Background/Purpose:

Henoch-Schonlein purpura (HSP) is a small vessel vasculitis characterized by non-thrombocytopenic purpura, abdominal pain, arthritis, and glomerulonephritis. Typically, HSP is self-limited, but more severe cases may require corticosteroid (CS) treatment. Rarely, a subset of patients has persistent rash, arthritis, abdominal involvement, or renal disease despite treatment with CS, or has disease recurrence on CS tapering. Although there is no consensus definition for refractory HSP, the 1-2 month timeframe is commonly used by many experts to determine refractoriness to daily oral CS treatment. Nevertheless, refractory HSP has been effectively treated with a variety of CS sparing therapies. For severe refractory HSP, the B cell depleting agent, rituximab (RTX), has been reported as beneficial for children with substantial renal or central nervous system involvement (J Pediatr 2009;155:136). However, RTX use for children with less severe HSP, but chronic CS dependent disease refractory to CS sparing immunomodulatory agents, has been less well explored. Herein, we describe 8 children treated with RTX for chronic refractory HSP and report a reduction in recurrent hospitalizations and eventual CS discontinuation.    

Patients and Methods:

Children diagnosed with HSP treated with RTX during the years 2008-2012 at a single institution were retrospectively identified through the electronic medical record. Clinical, laboratory, and therapeutic data were abstracted, including the presenting symptoms, the type and duration of treatment received, and the number of hospitalizations prior to and after RTX. Data were stored on an Excel spreadsheet and were subjected to the appropriate analyses and statistical tests.

Results:

Eight children (ages – 2 months to 16 years, 5 male), not previously reported, treated with RTX for chronic CS dependent HSP were identified (Table). In addition to palpable purpura (8), they suffered gastrointestinal distress/bleed (7), hematuria and/or proteinuria (7), and arthritis (1). Seven received long-term CS use, and 7 received various immunomodulatory therapies (methotrexate, azathioprine, mycophenolate mofetil, cyclophosphamide, and IVIg). All 8 received 1-6 rounds (two 750mg/m² doses, max. 1 gm/dose) of RTX with good B cell depletion. The incidence rate of hospital admission before and after receiving RTX was 1.78 vs. 0.68 per year, respectively, yielding an incidence rate ratio of 0.38 (confidence interval of 0.11 – 1.1, p = 0.06). Six achieved full remission off CS. The mean total oral steroid dose of RTX revealed a non-statistically significant reduction (p = 0.668). No serious adverse events were noted.

Conclusion:

RTX appears to be an effective and safe therapy for chronic CS dependent and immunomodulatory refractory childhood HSP. Future prospective analyses of RTX use for treatment of chronic CS dependent HSP will be worthwhile.