Henoch-Schonlein and IgA Nephropathy: are they the same disease?

Shaun Jackson, MD Division of Pediatric and Pediatric , Dept. of Pediatrics, University of Washington; Seattle Children’s Hospital Division of Nephrology HSP vs. IgA nephropathy?

Division of NephrologyDivision of Nephrology Disease spectrum or distinct entities?

1. Case report: Single patient with biopsy-proven IgA nephropathy then HSP nephritis. 2. Care report: Identical twins with adenovirus infection and subsequent development of HSP nephritis (rash, abdominal pain, plus renal disease) and renal-limited IgA nephropathy.

1. Ravelli, et al. 1996;72:111–112 2. Meadow, et al. Journal of Pediatrics 106 (1) 1985. Division of NephrologyDivision of Nephrology Pathogenesis: HSP and IgA nephropathy

* Davin, J.-C. & Coppo, R. Nat. Rev. Nephrol. 2014. * Rodrigues,et al. Clin J Am Soc Nephrol 12: 677–686, 2017.

Division of NephrologyDivision of Nephrology Henoch Schönlein Purpura vs. IgA nephropathy

Despite similar histopathology findings and possibly overlapping pathophysiology, HSP and IgA nephropathy have distinct clinical presentations, epidemiology, and long-term prognoses.

Division of NephrologyDivision of Nephrology Henoch Schönlein Purpura (HSP): A case…

• Phone call No. 1 (ED): 5 yo F with pain and swelling of bilateral knees, wrists and ankles for last 2 days. Mild URI symptoms for last week. No fever or rash. No sick contacts. • Phone call No. 2 (PCP): 2 days later, called by patient’s primary care physician. Joints still swollen…”is this JRA?” • Phone call No. 3 (ED): Back to Seattle Children’s ED with persistent joint pain/swelling and new rash…demanding that something be done.

Division of NephrologyDivision of Nephrology Henoch Schönlein Purpura (HSP) rash

Division of NephrologyDivision of Nephrology Henoch Schönlein Purpura (HSP) rash

Leukocytoclastic : • Post-capillary venules • Perivascular inflammatory cells

Division of NephrologyDivision of Nephrology Henoch Schönlein Purpura (HSP) tetrad

1. Rash 2. Abdominal pain 3. 4. Nephritis

Division of NephrologyDivision of Nephrology Henoch Schönlein Purpura: Epidemiology

• Disease of childhood • 75% ages 2-11

• Gender preference HSP! • M:F 1.5-2.0 (M>F)

• Seasonal variation • Spring, Fall, Winter > Summer

• Ethnicity Kawasaki • Caucasian, Asian > African

Division of NephrologyDivision of Nephrology Renal manifestations: Henoch Schönlein Purpura (HSP)

Unselected children with HSP < 17 years* * Narchi H. et al. Arch Dis Child. 2005 Sep;90(9):916-20. - Microscopic 11% - Macroscopic hematuria 5% - Hematuria and 10% - <1%

Retrospective cohort studies – 20-54%

Division of NephrologyDivision of Nephrology Who gets HSP nephritis?

Division of NephrologyDivision of Nephrology When does HSP nephritis develop?

Development of abnormal urinalysis (from Dx) - 4 weeks 85% - 6 weeks 91% - 6 months 97%

Screening for nephritis (urinalysis and BP) - Month 1 Weekly - Month 1-3 Every 2 weeks - Month 3-6 Monthly - Month 12

Division of NephrologyDivision of Nephrology IgA nephropathy

How does this disease differ from Henoch Schönlein Purpura?

Division of NephrologyDivision of Nephrology IgA nephropathy: clinical manifestations

1. Asymptomatic microscopic hematuria: - majority of patients, but dependent on screening practices. 2. Gross hematuria: - Concurrent with pharyngitis or other infection. - 10%–15% of subjects 3. Rarer presentation with significant nephritis: - Nephrotic syndrome - Rapidly progressive (RPGN)

Division of NephrologyDivision of Nephrology IgA nephropathy: Epidemiology

• Most common primary glomerulonephritis in the developed world. • Peak incidence: second and third decades.

1. Significant undiagnosed "latent" IgA nephropathy in the general population 2. Disease “prevalence” is affected by screening practices; genetic studies may be affected by comparison with normal "healthy" populations.

Division of NephrologyDivision of Nephrology Global prevalence of IgA nephropathy

Pediatric IgA nephropathy disease incidence (per 100,000/yr): - Japan: 4.5 - Tennessee: 0.57

Incidental glomerular IgA deposition on autopsy: - Japan: 15.6% - Finland: 1.3%

* Rodrigues,et al. Clin J Am Soc Nephrol 12: 677–686,Division 2017. of NephrologyDivision of Nephrology Prognosis: HSP vs. IgA nephropathy

HSP Nephritis IgA nephropathy Spontaneous resolution of Slow, but progressive, decline disease, except for the subset in renal function in patients with with more severe disease persistent proteinuria.

HSP Nephritis Outcomes Risk of permanent renal impairment Complete renal recovery (18 mo) Normal urinalysis 0% 94% children, 89% adults Isolated hematuria/proteinuria 1.6% Recurrent disease in 1/3. Nephritis/Nephrosis 19.5%

Division of NephrologyDivision of Nephrology IgA nephropathy: prognosis

* Reich, et al. JASN 2007,Division18 (12) of3177 Nephrology-3183 Division of Nephrology Treatment

Each disease poses a fundamental challenge to clinical trial design

HSP Nephritis IgA nephropathy High rates of spontaneous Slowly progressive immune resolution. Thus, only a subset disorder requiring: 1) long-term of patients can feasibly benefit clinical trials; 2) favorable from treatment. toxicity profile.

Division of NephrologyDivision of Nephrology Treatment – work for non-renal HSP

Who do I treat? 1) Severe abdominal pain 2) Severe joint pain 171 patients (84 prednisone, 87 placebo). 3) Patient’s requiring Treatment arm: Prednisone 1mg/kg/d x 2 weeks, hospitalization Weaned x 2 weeks Results: - Decreased joint pain (pain score 4.6 vs 7.3; P = .030). - Decreased abdominal pain (2.5 vs 4.8; P = .029)

Division of NephrologyDivision of Nephrology HSP nephritis treatment

2 randomized controlled trials.

- Henoch-Schönlein purpura nephritis: course of disease and efficacy of . Tarshish et al. Pediatr Nephrol (2004) 19:51–56.

- Ronkainen J, et al.. Cyclosporine A (CyA) versus MP pulses (MP) in the treatment of severe Henoch-Schonlein Nephritis (HSN). Pediatr Nephrol 2006;21:1531.

Division of NephrologyDivision of Nephrology HSP nephritis treatment: what do we do?

Risk stratification: Mild disease: 1) Degree of proteinuria – Prednisone taper (+/- second agent) 2) Renal biopsy to evaluate for crescentic disease Moderate disease: Treatment: – Prednisone taper + MMF 1) (Off-label use of Steroids, cyclophosphamide, Severe disease (crescentic GN): mycophenolate mofetil) - Methylprednisilone pulses, 2) Balance treatment of nephritis vs. prednisone taper, risk of immunosuppression cyclophosphamide.

Division of NephrologyDivision of Nephrology IgA nephropathy treatment

1. Optimization of proteinuria control - ACE inhibitor, ARB 2. Immunosuppression:

Division of NephrologyDivision of Nephrology IgA nephropathy treatment: STOP IgA Trial

• 6-month run-in period for BP control and RAS blockade • Randomized to: corticosteroids (eGFR >60 ml/min/1.73m2); corticosteroids plus cyclophosphamide / maintenance (eGFR 30–59 ml/min/1.73m2). 3 year study: • Full clinical remission > in immunosuppression arm (17% vs. 5%) • No difference in proportion with >15mo ml/min/1.73m2 drop in eGFR (28% supportive-care vs. 26% immunosuppression) Side-effects: • Increase in infection (incl. 1 sepsis-related death), glucose intolerance and weight gain.

* Rauen, et al. NEJM, 2015.Division of NephrologyDivision of Nephrology Summary

HSP Nephritis IgA nephropathy • Common pediatric vasculitis • Commonest primary glomerular • Renal involvement common, but disease typically mild and self-resolving. • Wide disease spectrum: majority • Progression to end-stage renal undiagnosed disease can occur in severe • Commonest presentation: Acute cases. macroscopic hematuria concurrent • Paucity of clinical trials makes with intercurrent URI treatment choices difficult. • Treatment: ACE inhibition plus tailed immunosuppression balancing efficacy with toxicity.

Division of NephrologyDivision of Nephrology

Division of Nephrology