Open access Protocol BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from Amyotrophic lateral sclerosis and the innate immune system: protocol for establishing a biobank and statistical analysis plan

Anne-­Lene Kjældgaard ‍ ‍ ,1,2 Katrine Pilely,2 Karsten Skovgaard Olsen,1 Anne Øberg Lauritsen,1 Stephen Wørlich Pedersen,3 Kirsten Møller,1,4 Peter Garred2,4

To cite: Kjældgaard A-L,­ ABSTRACT Strengths and limitations of this study Pilely K, Olsen KS, et al. Introduction Amyotrophic lateral sclerosis (ALS) is a Amyotrophic lateral sclerosis devastating, progressive disease that causes degeneration ►► This prospective, observational study ensures a na- and the innate immune system: of the motor neurons leading to paresis of the bulbar and protocol for establishing tional amyotrophic lateral sclerosis (ALS) biobank the skeletal musculature. The pathogenesis of ALS remains a biobank and statistical which will facilitate many future clinical studies of a unknown. We will test the hypothesis that the complement analysis plan. BMJ Open rare disease such as ALS. system is involved in the pathophysiology of ALS. This 2020;10:e037753. doi:10.1136/ ►► Even though ALS is a heterogeneous disease, all pa- protocol article describes our efforts to establish a bmjopen-2020-037753 tients face a rapid deterioration and severe distress national Danish ALS biobank. The primary aim is to obtain and the design of this study provides recruitment of ►► Prepublication history for biological material from patients with ALS for the current this paper is available online. patients with ALS at an early clinical stage hence study as well as for future studies. To view these files, please visit facilitating trial participation. Methods and analysis We intend to establish an the journal online (http://​dx.​doi.​ ►► The diagnosis of ALS is difficult, and patients fol- observational ALS biobank; some of the material from org/10.​ ​1136/bmjopen-​ ​2020-​ low highly variable courses of disease; thus, some this biobank will be used for a prospective, observational 037753). patients who have been recruited for the study will case–control study. The participants are patients with ALS, eventually be diagnosed with other diseases and Received 18 February 2020 neurologically healthy controls and non-ALS­ neurological Revised 04 May 2020 need to be excluded from the present study; con-

controls. Each participant consents to be interviewed and http://bmjopen.bmj.com/ versely, some patients who are in the early phase of Accepted 29 June 2020 to donate blood and cerebrospinal fluid to the biobank. ALS may be missed because of atypical symptoms Analysis of the complement system will be carried out on and will therefore be recruited in a later phase. the three groups of patients and compared. Ethics and dissemination The project has been approved by the Committees on Health Research Ethics in the Capital Region of Denmark (Approval number 000. In 70% of all ALS cases, initial symp- H-16017145) and the Danish Data Protection Agency (file toms appear in the upper or lower extrem- number 2012-58-0004). All results will be published in ities (spinal ALS), in 5% symptoms initially peer-reviewed,­ medical journals and presented at scientific on September 28, 2021 by guest. Protected copyright. conferences. appears in the truncus (truncal ALS), and in Trial registration number NCT02869048 25% a bulbar onset (bulbar ALS) is seen. In a systematic review of the global epidemiology of ALS, the median survival time was reported INTRODUCTION as 24–48 months from symptom onset.2 Amyotrophic lateral sclerosis (ALS) is an Five per cent to ten per cent of all ALS cases aggressive disease that causes progressive are of the familial type (fALS) which is genet- degeneration of the upper and lower motor ically heterogeneous mainly with a Mende- © Author(s) (or their neurons leading to severe muscular dystrophy, lian inheritance pattern.3 In the remaining employer(s)) 2020. Re-­use fasciculations, hyper-­reflexia and paresis of patients, there is no family history (sporadic permitted under CC BY-­NC. No 3 commercial re-­use. See rights the bulbar and skeletal musculature. As the ALS (sALS)). and permissions. Published by disease inevitably progresses, the patient The pathogenesis of ALS remains unknown BMJ. becomes unable to move, speak, swallow and and presently, there is no effective treatment For numbered affiliations see breathe. In addition to the neuromuscular to stop the progression. The immune system end of article. symptoms, frontotemporal dementia appears has been hypothesised to be an important, 1 Correspondence to in up to 15% of all patients with ALS. pathophysiological factor. This is based on Dr Anne-­Lene Kjældgaard; ALS is a rare disease with an incidence of the fact that immunological reactions appear akja0044@​ ​regionh.dk​ 1–2/100 000 and a prevalence of 4–6/100 both in the proximity of the degenerating

Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753 1 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from motor neurons in the central nervous system (CNS) and for the longitudinal cohort study, substudy 3, is planned systemically.4 to continue as long as the included patients with ALS The complement system plays a central role in the consent to lumbar puncture, blood sampling, and a short innate immune system. The complement system initi- interview every 6 months, if possible. ates inflammation and activates innate as well as adap- tive immune cells by detecting invading pathogens or Patient and public involvement damaged host cells. Patients or the public were not involved in the design, According to recent animal models of ALS, the very conduct, reporting or dissemination plans of this research. first detectable pathophysiological changes are seen in the neuromuscular junctions and might be a sign of Participants aberrant complement activation.5 6 Such inappropriate The national ALS bio-bank­ comprises samples from activation of the complement cascades may participate three groups of patients: patients with ALS, neurolog- in the initiation of the destruction of the neuromuscular ically healthy patients (healthy controls) and patients junctions by an autoinflammatory mechanism. Further- with neurological diseases other than ALS (neurological more, aberrant complement activation has been found in controls, NCs). All the participants included are above the proximity of the degenerating motor neurons during 18 years. ALS progression. In addition, findings of complement Patients with ALS activation in the blood and in the muscle tissue, as well Patients referred to an ALS outpatient clinic at either of as an unexplained erythrocyte cytotoxicity phenomenon five Danish hospitals (table 2) due to symptoms suspected found in the plasma of patients with ALS, suggest that the to be early symptoms of ALS are informed and invited complement system could play an important role in the 4 7 to participate in the project during the standard clinical pathophysiology during the progression of ALS. workup. If a patient at the end of the planned workup is To be able to develop an effective medical treatment, it diagnosed with either probable or definite ALS according is essential to study the pathogenesis and the pathophys- to El Escorial Revised criteria9 and consents to inclusion, iology of ALS. Since complement inhibition employing the patient is included in the project. Furthermore, all the terminal complement inhibitor ravulizumab now probable or definite patients with ALS who have already is entering a phase 3 clinical trial for the treatment of been permanently associated to an ALS outpatient clinic ALS, it is crucial to firmly establish how the complement (post clinical investigation) and who accept to undergo system affects the progression of ALS (https://news.​ ​alex- an additional lumbar puncture are invited to be part of ionpharma.​com). Understanding the pathophysiology of the project. the disease provides a tool to develop diagnostic methods such as biomarkers. This may optimise the diagnostic Neurologically healthy controls http://bmjopen.bmj.com/ process ensuring a faster and more precise diagnosis. In Neurologically healthy patients scheduled for elective addition, this could increase the knowledge of the hetero- orthopaedic surgery under spinal anaesthesia are invited geneity of the ALS symptoms. to participate.

Aim Neurological controls The overall, long-­term objective of this project is to estab- Patients admitted to hospital due to acute symptoms lish an ALS biobank to facilitate future basic ALS research. consistent with a subarachnoid haemorrhage are all Under the assumption that ALS is an autoinflamma-

subjected to a CT scan of the head. If this scan is without on September 28, 2021 by guest. Protected copyright. tory disease, another aim of the project is to disclose any signs of haemorrhage, an acute lumbar puncture will whether complement activation plays an essential role in be carried out. We recruit participants for the NC group the pathophysiology of ALS. The protocol describes the from this group of patients and the primary investigator design and data collection methods in detail in order to performs the lumbar puncture. Furthermore, patients inform other researchers of the biobank. who are referred for a planned lumbar puncture as part of a clinical neurological investigation due to neurolog- ical symptoms are also recruited for the NC group. METHODS Design Exclusion criteria for the two control groups This Danish national ALS biobank project is designed as Subjects with motor neuron disease, chronic inflam- a prospective, observational case–control study, based on matory or autoimmune diseases are excluded from the the Standard Protocol Items: Recommendations for Inter- neurologically healthy control (NHC) group and the NC 8 ventional Trials guidelines. The biobank will be estab- group. lished to facilitate future studies. The first study comprises four substudies (substudy 1–4, table 1) of which substudy Settings 1 and 2 are ongoing and the recruitment of participants Patients with ALS are recruited from five ALS outpa- for substudy 3 and 4 is planned to begin in the fall, 2020. tient clinics at five Danish neurological departments: Collection of biological material from patients with ALS Bispebjerg Hospital, Rigshospitalet (Glostrup) (both

2 Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from

Table 1 Overview and the inclusion status of the four substudies Substudy 1: a case–control study: haemolytic activity in ALS plasma Course of study ►► Interviews. ►► Blood samples. ►► Separation of red blood cells and plasma. ►► Red blood cells incubated with blood type matched plasma with or without inactivated complement system. ►► The degree of haemolysis is measured and compared. Subjects: aim/included so far ALS: 25/25 NC: 25/25 NHC: 25/25 Substudy 2: a case–control study: collection of material for biobank and profiling of the complement system Course of study ►► Interviews. ►► Blood samples and cerebrospinal fluid by lumbar puncture. ►► Biological material is prepared and freezed on site (−20°C). ►► Transportation of samples to central biobank for storage (−80°C). ►► Profiling of the complement system comparing the three groups. Subjects: aim/Included so far ALS: 100/98 NC: 100/61 NHC: 100/96 Substudy 3: a cohort study: collection of material for biobank and a study of the complement system over time Course of study ►► The same course as in Substudy 2 repeated every 6 months Subjects: aim/Included so far ALS: 20/0 NC: — NHC: — Substudy 4: pilot study: searching for complement activity in the neuromuscular junctions of patients with ALS Course of study ►► Interviews. ►► Tru-­cut biopsy from dominant lateral vastus muscle. ►► Transportation of muscle biopsy to Department of Neuropathology, Hospitalise. ►► Analysis of complement activity in muscle fibres and neuromuscular junctions. Subjects: aim/Included so far ALS: 10/0 NC: — NHC: —

ALS, amyotrophic lateral sclerosis; C, celsius; NC, neurological controls; NHC, neurologically healthy controls. http://bmjopen.bmj.com/

University of Copenhagen), Roskilde University Hospital, are transported in a −20°C freezer to a central biobank Odense University Hospital, and Aarhus University where they are stored at −80°C (figure 1). Hospital. NHCs are recruited at Gildhøj Private Hospital, Denmark. Controls from the neurological group are Biological samples recruited at the neurological department at Rigshospi- Blood samples talet (Glostrup), Denmark. At each hospital, one local Venous blood samples are collected by the primary inves- on September 28, 2021 by guest. Protected copyright. investigator is appointed. During sample collection, the tigator or by a skilled clinical nurse. Blood is collected primary investigator is present to obtain biological mate- in sample 1: ethylenediaminetetraacetic acid (EDTA) rial from each patient and to process and freeze the blood tube (8 mL), sample 2: hirudin blood tubes (8 mL), samples using a portable ‘mini-­lab’. All data collected on sample 3: heparin lithium plasma tubes (8 mL), sample 4: case report forms are anonymised, gathered and stored blood tube with clot activator for serum (8 mL), sample in an audited, central, electronic database. All biological 5: PAXgene tube with RNAlater (2.5 mL). Samples 1–3 material is transported to the Department of Clinical are centrifuged immediately at 2000 g for 10 min. The Immunology at Rigshospitalet, Denmark to be stored in supernatant (plasma) is aliquoted in small volumes into biobanking facilities. 1.5 mL tubes. The precipitate from sample 1 is aliquoted into 1.5 mL tubes. Sample 4 is kept for 45–60 min at Data collection room temperature and is then centrifuged at 2000 g for In patients with ALS and patients in the NC group, 10 min. The supernatant (serum) is aliquoted in small blood samples are drawn from a peripheral vein after volumes into 1.5 mL tubes. All samples are processed by the performance of the lumbar puncture. In NHCs, for the primary investigator. Subsequently, all the processed logistical reasons, the blood samples are drawn before the samples are transported in a −20°C freezer and stored in lumbar puncture. All the samples are processed by the a central biobanking facility at −80°C. Sample 5 is placed primary investigator at the respective inclusion site and vertically at room temperature for 24–72 hours, is frozen

Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753 3 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from

Table 2 Demographic data of the included patients with Table 2 Continued ALS in substudy 2 Characterisation of the ALS group (n: 96) n % Characterisation of the ALS group (n: 96) n %  No 75 78 Inclusion site Riluzole treatment on data collection day  Glostrup Hospital 9 9  Yes 33 34  Bispebjerg Hospital 33 34  No 63 66  Roskilde Hospital 33 34 ALS, Amyotrophic lateral sclerosis; ALSFRS-­R, Amyotrophic Lateral  Odense Hospital 16 17 Sclerosis Functional Rating Scale-­Revised.  Aarhus Hospital 5 5 Age (median age: 67) at −20°C for 24–72 hours, and is subsequently stored at  <40 3 3 −80°C.  40–49 12 13  50–59 13 14 Cerebrospinal fluid samples  60–69 28 29 On lumbar puncture, the first 1 mL of cerebrospinal fluid  >70 40 42 (CSF) obtained is discarded. Thereafter, 4–6 mL of CSF is obtained as feasible. Samples are immediately centri- Age when first symptoms occurred (median age: 65) fuged at 2000 g, and the supernatant is aliquoted into  <40 4 4 1.5 mL tubes.  40–49 13 14  50–59 15 16 Biobank facility  60–69 35 36 The processed blood samples and the processed CSF samples will be stored in a biobank in a −80°C freezer  >70 29 30 located at Laboratory of Molecular Medicine, Depart- Gender ment of Clinical Immunology, Rigshospitalet, Copen-  Female 40 42 hagen, Denmark.  Male 56 58 ALS subtype I Muscle biopsies (substudy 4) After injection of local anaesthesia (lidocaine 2%) one  Familial ALS 2 2 tru-­cut biopsy is obtained containing 100 mg of skeletal  Sporadic ALS 94 98 muscle tissue from the lateral vastus muscle. The biopsy ALS subtype II is transported to the Department of Neuropathology, http://bmjopen.bmj.com/  Spinal ALS 60 63 Rigshospitalet for further processing.  Bulbar ALS 28 29 Base-line information Both spinal and bulbar ALS 6 6 The following demographic information about the  Truncal ALS 2 2 patients with ALS are collected: age, gender, subtype of ALSFRS-R­ score on date collection day (median score: 37): disease, current stage of disease, T0 (defined as the month Mild ALS symptoms (ALSFRS-R­ score >36) 49 51 Moderate ALS symptoms (24< ALSFRS R 33 34 on September 28, 2021 by guest. Protected copyright. score ≤36) Sever e ALS symptoms (ALSFRS-R­ score ≤24) 14 15 Progression rate estimation (Δtime*ALSFRS-R­ score on data collection day) Slow progression rate 26 27 Medium progression rate 37 39 Aggr essive progressive rate 33 34 Overall survival time from onset of symptoms (Database update: 2 May 2020) Still alive (missing data) 39 41 Short survival time (0–2 years) 22 23 Medium survival time (2–4 years) 25 26 Long survival time (4+ years) 10 10 Cognitive impairments observed  Yes 21 22 Figure 1 Collection of biological material.EDTA, ethylenediaminetetraacetic acid; g, therelative centrifugal Continued force; RNA, ribonucleidacid

4 Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from

ELISA experiments are performed at the Laboratory of Molecular Medicine, Rigshospitalet, using specific monoclonal antibodies as previously described.11–23 Total serum concentrations of C4 and C3 are quantified by an automated turbidimetric protein analyser (SPAPLUS, The Binding Site group LDT, Birmingham, UK) where sheep polyclonal antibodies against either human C3c or human C4 are applied (The Binding Site group LDT, Birmingham, UK).

Cytokine measurement Selected cytokines as well as acute phase reactants will Figure 2 Inclusion and baseline registration. ALS, be analysed with a multiplex sandwich immunoassay amyotrophic lateral sclerosis; ALSFRS-­R, Amyotrophic with electrochemiluminescence: plates, precoated with Lateral Sclerosis Functional Rating Scale-­Revised; NMD, capture antibodies for the cytokines, are incubated with neuromuscular disease; SAH, subarachnoid haemorrhage; T0, plasma samples. Subsequently, detection antibodies are time of first symptoms (month and year). put in the wells and then the plates are incubated. After washing, the detection levels are measured. and year of the first subjective symptoms that later led to RNA expression and proteomics studies the diagnosis of either probable ALS or definite ALS), Full blood is obtained in PAXgene Blood RNA tubes with treatment with riluzole, daily medication and observed RNA later, an RNA stabilising buffer, for future isolation cognitive changes. Data are pseudonymised and entered of RNA and gene expression profiling. At that point in into an Excel database only accessible for A-­LK, PG and time, we will be able to conduct proteomic analysis simul- KM and the database is updated, stored, and logged in taneously as well as using the same samples of whole accordance with Danish law and regulations set by the blood preserved in RNA later. Danish Data Protection Agency. An interview of all the patients with ALS, based on the questionnaire ALS func- Neuropathological studies tional Rating Scale-Revised­ (ALSFRS-R),­ 10 is conducted For immunofluorescence staining, sections of ALS by the primary investigator on the day of lumbar punc- muscle biopsies from the lateral vastus muscle is air-­dried ture and blood sampling (data collection day) and the and fixed in 4% paraformaldehyde at −20°C. Slides are score is noted in the database (figure 2). washed in phosphate-­buffered saline (PBS), permeabi-

lised in PBS/0.2% TritonX and blocked using PBS/5% http://bmjopen.bmj.com/ Clinical phenotyping fetal calf serum/0.2% TritonX. The sections are stained The subtype of ALS is noted: sALS/fALS and the subtype with primary antibodies directed against complement of spinal, bulbar or truncal ALS. Furthermore, it is noted components and regulators (anti-C3c,­ anti-C1q,­ anti-C4c,­ whether the ALS specialists observe any sign of cognitive anti-C5b-9­ and anti-CD59),­ followed by incubation with impairment. ALSFRS-­R score, estimated on the day of fluorescence marked secondary antibodies. The motor data collection, is noted. Patients are age categorised into end plates are visualised by incubating with Alexa 488 age groups. Time of the first appearance of symptoms conjugated antibungarotoxin, which binds to postsyn-

(T0) is noted and the clinical status on data collection day aptic acetylcholine receptors on the muscle fibres, thus on September 28, 2021 by guest. Protected copyright. is categorised. visualising the end plates. After staining, the sections are washed in PBS, air dried and mounted on slides. The Analysis muscle sections are analysed for complement staining Complement measurements and colocalisations with motor end plates using confocal The concentrations of complement components microscopy. Each motor end plate identified on the (ficolin-1, ficolin-2, ficolin-3, collectin-11, pentraxin 3 surface of a muscle fibre will be counted using automated (PTX3), mannose-­binding lectin (MBL), MBL/ficolin/ software, and the length of the end plates will be measured CL-­associated serine protease 3 (MASP-3), MBL/ficolin/ in the ALS muscle biopsies. The size of end plates will be Cl-­associated protein 1 (MAP-1), complement activa- measured and the number of immunoreactive areas per tion products (C4c, C3bc, sC5b-9) as well as comple- section will be scored. ment activation potentials (measured as activation on pathway-specific­ ligands: human serum albumin/ Outcome measures, sample size and statistics for each antihuman serum albumin immune complexes for substudy classical pathway activation; lipopolysaccharide for alter- Substudy 1 native pathway activation; mannan for MBL-mediated­ Primary and explorative outcomes lectin pathway activation; and acetylated bovine serum The primary outcome is the difference in haemolytic albumin for ficolin-mediated­ lectin pathway activation) activity of plasma against healthy red erythrocytes as are measured by ELISA in plasma and CSF samples. The measured by absorbance between patients with ALS and

Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753 5 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from

NHCs. The difference in haemolytic activity between Cut-off­ values and predictive values are calculated using patients with ALS and NCs is an exploratory outcome. ROC curves.

Sample size Substudy 3 Overgaard et al measured the haemolytic activity after Primary and explorative outcomes incubation of healthy as well as ALS erythrocytes in both The primary outcome measure is the change in the healthy plasma and ALS plasma. They described a mean plasma/CSF concentration ratio of ficolin-3 over time difference of 0.20 (SE 0.052 in the group of patients with in patients with rapid progression compared with those ALS, number 20, SD 0.22) in the absorbance (415 nm, with slow progression. The concentrations in plasma and incubation: 5 hours) between ALS group and group CSF of ficolin-1, ficolin-2, ficolin-3, collectin-11, PTX3, 24 of healthy controls. At α=0.05 and β=0.20, we need MASP-3, MBL, MAP-1, C4c, C3bc, sC5b-9 as well as the to include 21 participants in each group. Taking into plasma/CSF concentration ratios of ficolin-1, ficolin-2, account possible dropouts, failed technical tests, inclu- collectin-11, PTX3, MASP-3, MBL, MAP-1, C3bc, C4c and sion of 25 persons per group is planned. sC5b-9 are exploratory outcomes.

Statistical analysis Sample size The haemolytic activity in the three groups (patients with To our knowledge, no prior studies describe the activity ALS, NCs, NHCs) will be compared using one-way­ anal- of the complement system in patients with ALS over time. ysis of variance (ANOVA) followed by t-­tests to pinpoint This is hence a pilot study for which no sample size calcu- differences between groups. cut-off­ values and predictive lation has been made. We will include 20 patients with values will be calculated using receiver operating charac- ALS. teristic (ROC) curves. Statistical analysis Substudy 2 Analyses are carried out as described for substudy 2. In Primary and explorative outcomes addition, we will conduct linear regression analyses with The primary outcome is the activation potential of the the levels of complement proteins as the dependent vari- ficolin-­mediated lectin pathway. The activation potential able and time since onset of disease, gender, age and of the classical pathway, the alternative pathway and the subtype of ALS as explanatory variables. MBL-­mediated lectin pathway are exploratory outcomes. Substudy 4 Sample size Primary and explorative outcomes The number of subjects in each group is calculated using The primary outcome is the presence of any marker of

an α=0.05 and β=0.20. We compare the complement acti- the complement system in the neuromuscular junction http://bmjopen.bmj.com/ vation potential of three equal-­sized groups. In healthy as visualised by confocal microscopy of muscle biopsies subjects, the complement activation potential is 100% from patients with ALS. These putative observations will with a normal area ranging from 50% to 150%, and the be compared against an existing normative sample of prevalence of subjects with a low complement activation muscle biopsies. potential (under 50%) is under 10%. If 100 subjects are included in each group, it will be possible to detect statis- Sample size tically significant differences between the groups corre- This is a hypothesis-­generating study as the presence of complement activity in living patients with ALS have sponding to an OR of 2.3, which would correspond to on September 28, 2021 by guest. Protected copyright. 20% of patients with ALS having a low complement activa- not been described previously; therefore, no sample size tion potential caused by increased complement activity.25 calculation has been made. We will include 10 patients with ALS. Statistical analysis The concentration of complement markers and the Statistical analysis complement activation potential will be compared Complement depositions in the muscle fibres and in between patients with ALS and the two control groups particular in the neuromuscular junctions are described using stepwise ANOVA followed by t-­tests, Bonferroni-­ qualitatively. The samples are scored by an investigator, corrected as appropriate. If necessary, we will log-­ who is blinded to clinical information, into either transform the data to ensure a Gaussian distribution. The ‘normal’, ‘light degree’ or ‘Severe degree’ of changes. covariates, that will be used for the stepwise ANOVA to These assessments will be compared with 2 x K tables and test for differences between the three groups, are subject non-­parametric statistics. category (patient with ALS, NHC or NC), gender and age. The patients with ALS will be described and categorised by the covariates as illustrated in table 1. We will analyse DISCUSSION the covariates and the response variables by doing step- ALS is a rapidly progressive, fatal disease. Despite the wise, one-way­ ANOVA to test for differences between the aggressive course and devastating consequences, there is ALS subtypes. currently no effective treatment of ALS.

6 Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from

This manuscript describes the generation of a Danish Retrospectively, it has been common procedure to ALS biobank that will hopefully provide a starting point include patients with probable or definite ALS in clin- for future national ALS research. With the present ical ALS research projects. Some patients have slowly project, a substantial amount of biological material from progressing symptoms of a motor neuron disease which patients suffering from ALS will be obtained. We hope initially do not meet the criteria of probable or definite that the project will bring ALS research a significant step ALS as the upper and lower motor neurons are not yet forward, will inspire other groups to start similar projects both affected. Even so, the symptoms may progress in regarding this and other rare diseases, and hence will which case the patient will eventually meet the criteria enable future basic biobank research within this chal- of probable or definite ALS. With the inclusion criteria lenging field. stated for the present protocol, we realise that we may The generation of this biobank was inspired by the miss inclusion of this subset of (possible) patients with hypothesis that the innate immune system plays a signif- ALS and hence the opportunity to observe the initial icant role in the pathogenesis or the pathophysiology of phase of such patients.32 ALS. With a specific aim to profile the complement system Information about cognitive impairment/changes in patients with ALS, it became important to ensure that registered in the electronic patient file has been entered the two control groups do not include patients with into the database. However, less severe symptoms in some diseases with neither primary nor secondary complement cases of cognitive impairment might be overlooked by activation even if this means that the two control groups the clinicians, and ideally, patients should undergo stan- will not be comparative in age and gender. dardised, neuropsychological testing. However, as it was Several initiatives have conducted multicentre, interven- not within the scope of this project to ensure neuropsy- tional clinical trials and established large ALS biobanks.26 chological testing of the patients with ALS, we elected to Continuing the collection of biological material from rely on the practice of the clinical inclusion sites, which patients with this rare disease will maintain and expand unfortunately does not always comprise testing, regard- the capacity to study the increasing number of hypoth- less of cognitive changes. eses generated by the spatiotemporal studies conducted Substudy 4 is a pilote study based on tru-cut­ skeletal on animal ALS models.5 6 27 28 With the present protocol, muscle biopsies from 10 patients with ALS. Since only we intend to obtain biological material from patients with one biopsy is obtained from each patient, this is a rather ALS starting in a relatively early phase of clinical disease. small amount of tissue in particular for a neuromuscular-­ Furthermore, patients with ALS are invited to participate junction study. We chose this option as a compromise in the cohort study (substudy 3) which will add a spatio- given the pilot nature of the study, to inflict as little pain temporal aspect to the biobank. as possible on the patient. All Danish citizens are registered in the National Patient The NHCs in the biobank and hence also for the four http://bmjopen.bmj.com/ Registry (DNPR) which is one of the oldest complete, substudies are included if they have no neurological national patient registries in the world. DNPR is linkable symptoms based only on the anamnesis. However, to on an individual level with other clinical and administra- ensure that these are neurologically healthy, one could tive registries.29 Hence, this poses a unique possibility to argue that all the NHCs should have a clinical neurolog- conduct registry-­based research combined with data from ical examination performed as well as an MRI scan of the this ALS biobank in future studies. CNS before inclusion. More than 20 genetic mutations have been associ- ated with ALS, the most well-­known and well-­researched Author affiliations 1 on September 28, 2021 by guest. Protected copyright. mutations being the SOD1, FUS, TARDBP and C9ORF72 Neuroanaesthesiology, The Neuroscience Centre, Rigshospitalet, Copenhagen, 30 Denmark genes. Even though ALS seems to have a multifactorial 2Laboratory of Molecular Medicine, Department of Clinical Immunology Section aetiology, genetic mutations may play a pivotal role in 7631, Diagnostic Centre, Rigshospitalet, Copenhagen, Denmark the pathogenesis of ALS. Our planned substudies do not 3Neurology, The Neuroscience Centre, Rigshospitalet, Glostrup, Denmark include genetic analysis. However, future genetic studies 4Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of will be possible as biological material in the form of EDTA Copenhagen, Copenhagen, Denmark precipitate will be secured for the biobank. Acknowledgements The authors are most grateful towards all the patients that consent to participate in this study. Furthermore, we wish to thank clinicians and researchers at the neurological departments that are inclusion sites for the TRIAL LIMITATIONS substudies, as well as Gildhøj Private Hospital, which is the inclusion site for All patients have been interviewed by the same person neurologically healthy patients. preventing inter-­rater variability. The possibility of Contributors KSO, SWP, AØL, KM, PG and A-­LK conceived and designed the study. A-­LK drafted the protocol, and A-­LK, KSO, SWP, AØL, KP, KM and PG revised the reporting bias is not prevented, however, as the inter- protocol for important intellectual content. A-­LK, AØL, KSO and KM implemented the viewer might subtly change the way of questioning over study at the clinical departments. A-­LK drafted the manuscript. All authors revised time, even though they are using the same questionnaire the manuscript for important intellectual content and assume responsibility for the final version. for all patients. Additionally, the T0 can be difficult for the patients to define and remember and lead to imprecise or even incorrect answers.31

Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753 7 Open access BMJ Open: first published as 10.1136/bmjopen-2020-037753 on 5 August 2020. Downloaded from

Funding This work was funded by Aase and Ejnar Danielsen’s Foundation, The 13 Skjoedt M-­O, Palarasah Y, Munthe-­Fog L, et al. MBL-­associated Jascha Foundation, The Danish Research Foundation of Independent Research serine protease-3 circulates in high serum concentrations (DFF-6110–00489), and The Danish Heart Foundation (16-­R107-­A6650-22966). predominantly in complex with ficolin-3 and regulates ficolin-3 mediated complement activation. Immunobiology 2010;215:921–31. Competing interests None declared. 14 Skjoedt M-O,­ Hummelshoj T, Palarasah Y, et al. Serum concentration and interaction properties of MBL/ficolin associated protein-1. Patient consent for publication Not required. Immunobiology 2011;216:625–32. Provenance and peer review Not commissioned; externally peer reviewed. 15 Seelen MA, Roos A, Wieslander J, et al. Functional analysis of the classical, alternative, and MBL pathways of the complement Open access This is an open access article distributed in accordance with the system: standardization and validation of a simple ELISA. J Immunol Creative Commons Attribution Non Commercial (CC BY-­NC 4.0) license, which Methods 2005;296:187–98. permits others to distribute, remix, adapt, build upon this work non-commercially­ , 16 Hein E, Honoré C, Skjoedt M-­O, et al. Functional analysis of ficolin-3 and license their derivative works on different terms, provided the original work is mediated complement activation. PLoS One 2010;5:e15443. properly cited, appropriate credit is given, any changes made indicated, and the use 17 Pilely K, Skjoedt M-­O, Nielsen C, et al. A specific assay for is non-­commercial. See: http://​creativecommons.org/​ ​licenses/by-​ ​nc/4.​ ​0/. quantification of human C4c by use of an anti-­C4c monoclonal antibody. J Immunol Methods 2014;405:87–96. Author note A steering committee will be established with representatives from 18 Garred P, Mollnes TE, Lea T. Quantification in enzyme-linked­ clinical as well as basic ALS research groups in order to ensure easy access to the immunosorbent assay of a C3 neoepitope expressed on activated collected biological material for future, state-­of-­the-­art ALS research projects. human complement factor C3. Scand J Immunol 1988;27:329–35. 19 Mollnes TE, Lea T, Frøland SS, et al. Quantification of the terminal ORCID iD complement complex in human plasma by an enzyme-­linked Anne-Lene Kjældgaard­ http://orcid.​ ​org/0000-​ ​0002-7197-​ ​8298 immunosorbent assay based on monoclonal antibodies against a neoantigen of the complex. Scand J Immunol 1985;22:197–202. 20 Garred P, Madsen HO, Kurtzhals JA, et al. Diallelic polymorphism may explain variations of the blood concentration of mannan-­binding protein in Eskimos, but not in black Africans. Eur J Immunogenet REFERENCES 1992;19:403–12. 1 Phukan J, Pender NP, Hardiman O. Cognitive impairment in 21 Munthe-­Fog L, Hummelshøj T, Hansen BE, et al. The impact of FCN2 amyotrophic lateral sclerosis. Lancet Neurol 2007;6:994–1003. polymorphisms and haplotypes on the ficolin-2 serum levels. Scand 2 Chiò A, Logroscino G, Traynor BJ, et al. Global epidemiology of J Immunol 2007;65:383–92. amyotrophic lateral sclerosis: a systematic review of the published 22 Munthe-­Fog L, Hummelshøj T, Ma YJ, et al. Characterization of a literature. Neuroepidemiology 2013;41:118–30. polymorphism in the coding sequence of FCN3 resulting in a ficolin-3 3 Philips T, Rothstein JD. Rodent models of amyotrophic lateral (Hakata antigen) deficiency state. Mol Immunol 2008;45:2660–6. sclerosis. Curr Protoc Pharmacol 2015;69:5.67.1-5.67.21. 23 Munthe-Fog­ L, Hummelshoj T, Honoré C, et al. Variation in FCN1 4 Kjældgaard A-­L, Pilely K, Olsen KS, et al. Amyotrophic lateral affects biosynthesis of ficolin-1 and is associated with outcome of sclerosis: the complement and inflammatory hypothesis. Mol systemic inflammation. Genes Immun 2012;13:515–22. Immunol 2018;102:14–25. 24 Overgaard K, Werdelin L, Sørensen H, et al. Cytotoxic activity in 5 Bahia El Idrissi N, Bosch S, Ramaglia V, et al. Complement plasma from patients with amyotrophic lateral sclerosis. Neurology activation at the motor end-­plates in amyotrophic lateral sclerosis. J 1991;41:925–7. Neuroinflammation 2016;13:72. 25 Armitage PBG. Statistical methods for medical researchers. 6 Heurich B, El Idrissi NB, Donev RM, et al. Complement upregulation Blackwell, 1994. and activation on motor neurons and neuromuscular junction in the 26 Sherman AV, Gubitz AK, Al-­Chalabi A, et al. Infrastructure resources SOD1 G93A mouse model of familial amyotrophic lateral sclerosis. J for clinical research in amyotrophic lateral sclerosis. Amyotroph Neuroimmunol 2011;235:104–9. Lateral Scler Frontotemporal Degener 2013;14:53–61. 7 Parker SE, Hanton AM, Stefanou SN, et al. Revisiting the role of 27 Wang H, Ricklin D, Lambris JD. Complement-­activation fragment the innate immune complement system in ALS. Neurobiol Dis C4a mediates effector functions by binding as untethered agonist http://bmjopen.bmj.com/ 2019;127:223–32. to protease-­activated receptors 1 and 4. Proc Natl Acad Sci U S A 8 Chan A-­W, Tetzlaff JM, Gøtzsche PC, et al. Spirit 2013 explanation 2017;114:10948–53. and elaboration: guidance for protocols of clinical trials. BMJ 28 Wang HA, Lee JD, Lee KM, et al. Complement C5a-­C5aR1 signalling 2013;346:e7586. drives skeletal muscle macrophage recruitment in the hSOD1G93A 9 Brooks BR, Miller RG, Swash M, et al. El Escorial revisited: revised mouse model of amyotrophic lateral sclerosis. Skelet Muscle criteria for the diagnosis of amyotrophic lateral sclerosis. Amyotroph 2017;7:10. Lateral Scler Other Motor Neuron Disord 2000;1:293–9. 29 Schmidt M, Schmidt SAJ, Sandegaard JL, et al. The Danish national 10 Cedarbaum JM, Stambler N, Malta E, et al. The ALSFRS-­R: a patient registry: a review of content, data quality, and research revised ALS functional rating scale that incorporates assessments of potential. Clin Epidemiol 2015;7:449–90. respiratory function. BDNF ALS Study Group (phase III). J Neurol Sci 30 Nowicka N, Juranek J, Juranek JK, et al. Risk factors and emerging

1999;169:13–21. therapies in amyotrophic lateral sclerosis. Int J Mol Sci 2019;20. on September 28, 2021 by guest. Protected copyright. 11 Bayarri-­Olmos R, Kirketerp-­Moller N, Pérez-­Alós L, et al. doi:10.3390/ijms20112616. [Epub ahead of print: 28 May 2019]. Development of a quantitative assay for the characterization of 31 Taylor-­Rowan M, Wilson A, Dawson J, et al. Functional assessment human Collectin-11 (CL-11, CL-­K1). Front Immunol 2018;9:2238. for acute stroke trials: properties, analysis, and application. Front 12 Bastrup-­Birk S, Skjoedt M-­O, Munthe-­Fog L, et al. Pentraxin-3 Neurol 2018;9:191–91. serum levels are associated with disease severity and mortality in 32 Al-­Chalabi A, Hardiman O, Kiernan MC, et al. Amyotrophic lateral patients with systemic inflammatory response syndrome. PLoS One sclerosis: moving towards a new classification system. Lancet Neurol 2013;8:e73119. 2016;15:1182–94.

8 Kjældgaard A-­L, et al. BMJ Open 2020;10:e037753. doi:10.1136/bmjopen-2020-037753