Intrathecal Immunoglobulin a and G Antibodies to Synapsin in a Patient with Limbic Encephalitis

Piepgras et al. 1

Appendix e-2

Intrathecal immunoglobulin A and G antibodies to synapsin in a patient with limbic encephalitis

Johannes Piepgras, Markus Höltje, Carolin Otto, Hendrik Harms, Annyesha Satapathy, Fabrizia Cesca, Fabio Benfenati, Daniel Gitler, Andreas Pich, Johannes- Friedrich Zander, Gudrun Ahnert-Hilger, Klemens Ruprecht

Table 1

Levels of immunoglobulin G to voltage-gated potassium channels in cerebrospinal fluid and serum

Aug. 7th Aug. 19th October November January June

2013 2013 2013 2013 2014 2014 CSF 17 9 7 2 4 <1 (pmol/l) Serum <1 27 <1 <1 <1 <1 (pmol/l)

Levels of immunoglobulin (Ig)G to voltage-gated potassium channels (VGKC) in cerebrospinal fluid (CSF) and serum as detected by radioimmunoassay (RIA) in a patient with limbic encephalitis and antibodies to synapsin. In CSF, values above 2 pmol/l, and in serum, values above 85 pmol/l are considered elevated. Piepgras et al. 2

Table 2-5

Titers of immunoglobulin (Ig)A and IgG antibodies to synapsin Ia and Ib, total

IgA and IgG concentration, and antibody indices (AIs) in paired cerebrospinal fluid (CSF) and serum samples of a patient with limbic encephalitis associated with antibodies to synapsin

Table 2

Synapsin Ia IgA

August 2013 October 2013 January 2014 June 2014 Antibody titer 1:1000 1:1000 1:1000 1:3200 CSF Antibody titer 1:1000 1:3200 1:1000 1:3200 serum Total IgA 0.127 0.158 0.04 0.039 CSF (mg/ml) Total IgA 2.22 2.15 2.3 1.62 serum (mg/ml) Antibody index 17.5 4.2 58 41

Table 3 Piepgras et al. 3

Synapsin Ib IgA

August 2013 October 2013 January 2014 June 2014 Antibody titer 1:10000 1:3200 1:320 1:1000 CSF Antibody titer 1:3200 1:3200 1:320 1:320 serum Total IgA 0.127 0.158 0.04 0.039 CSF (mg/ml) Total IgA 2,22 2,15 2,3 1,62 serum (mg/ml) Antibody index 54 13 58 130

Table 4

Synapsin Ia IgG

August 2013 October 2013 January 2014 June 2014 Antibody titer 1:32000 1:32000 1:3200 1:10000 CSF Antibody titer 1:10000 1:10000 1:3200 1:3200 serum Total IgG 0.217 0.181 0.15 0.133 CSF (mg/ml) Total IgG 21.9 9.85 8.37 8.33 serum (mg/ml) Antibody index 355 174 58 130

Table 5

Synapsin Ib IgG

August 2013 October 2013 January 2014 June 2014 Antibody titer 1:10000 1:32000 1:10000 1:10000 CSF Antibody titer 1:3200 1:10000 1:3200 1:3200 Piepgras et al. 4 serum Total IgG 0.217 0.181 0.15 0.133 CSF (mg/ml) Total IgG 21.9 9.85 8.37 8.33 serum (mg/ml) Antibody index 347 174 58 208

Antibody titers were obtained by incubating HEK293 cells transfected with either synapsin Ia or synapsin Ib plasmids with increasing dilutions of CSF or serum followed by a secondary anti-human IgA or IgG fluorescent antibody. Antibody indices were calculated using the formula: AI = (anti-synapsin titer CSF-1/anti-

-1 synapsin titer serum )/(total Ig CSF/total Ig serum). AI values above 4 are considered as evidence of an intrathecal antibody synthesis.1

REFERENCE

1. Reiber H, Lange P. Quantification of virus-specific antibodies in cerebrospinal fluid and serum: sensitive and specific detection of antibody synthesis in brain. Clin

Chem 1991;37:1153-1160.