Correlates of systemic disease in adult Henoch-Schönlein purpura: A retrospective study of direct immunofluorescence and skin lesion distribution in 87 patients at Mayo Clinic

BackgroundDetection of IgM in lesional skin of adult patients with Henoch-Schönlein purpura via direct immunofluorescence (DIF) has been associated with the presence of renal disease.ObjectiveWe sought to examine whether DIF findings of skin biopsy specimens and distribution of skin lesions were associated with the presence of systemic disease, including renal, gastrointestinal tract, and joint involvement.MethodsWe performed a retrospective review of adult patients with Henoch-Schönlein purpura seen at Mayo Clinic between 1992 and 2011.ResultsOf the 87 patients (mean age, 46.1 years), 51 (59%) were male. A total of 39 patients (45%) had renal disease; 32 (37%), gastrointestinal tract involvement; 39 (45%), joint involvement; and 65 (75%), some systemic involvement. In all, 61 patients (70%) had cutaneous lesions above the waist. The DIF findings showed the presence of IgA in all 87 patients (100%). In addition, findings were positive for IgM in 32 patients (37%); IgG in 3 patients (3%); C3 in 75 patients (87%); and fibrinogen in 78 patients (92%). IgM was not found to be significantly associated with renal disease (P = .10); however, absence of fibrinogen was correlated with presence of renal involvement (P = .04). No other correlations were detected between DIF findings and systemic disease. Lesions above the waist were not significantly associated with renal (P = .12) or any (P = .76) systemic involvement.LimitationsThis study is retrospective.ConclusionsNeither IgM in lesional skin nor distribution of skin lesions above the waist was a reliable indicator of renal or systemic disease in adults with Henoch-Schönlein purpura.