%0 Journal Article
%T Galactose-deficient IgA1 in skin and serum from patients with skin-limited and systemic IgA vasculitis.
%A Neufeld M
%A Molyneux K
%A Pappelbaum KI
%A Mayer-Hain S
%A von Hodenberg C
%A Ehrchen J
%A Barratt J
%A Suzuki Y
%A Sunderkötter C
%J J Am Acad Dermatol
%V 81
%N 5
%D Nov 2019
%M 30902725
%F 15.487
%R 10.1016/j.jaad.2019.03.029
%X <B>BACKGROUND: </B>IgA vasculitis (IgAV) encompasses a systemic form involving kidneys, gut, skin, or joints, and a skin-limited form. One characteristic feature of systemic IgAV is deposition of galactose-deficient IgA1 (GD-IgA1) in kidneys (as in IgA nephropathy). The relevance of GD-IgA1 for cutaneous vasculitis is unknown.<BR><B>OBJECTIVE: </B>We investigated whether GD-IgA1 is deposited perivascularly in systemic and also skin-limited IgAV and whether its serum levels differ between both forms.<BR><B>METHODS: </B>In a case-control study, deposition of GD-IgA1 was analyzed immunohistochemically by KM55 antibody in skin biopsy specimens from 12 patients with skin-limited IgAV and 4 with systemic IgAV. GD-IgA1 levels were compared by enzyme-linked immunosorbent assay in sera from 15 patients each with skin-limited and systemic IgAV and from 11 healthy individuals.<BR><B>RESULTS: </B>All biopsy samples from systemic IgAV, and also from skin-limited IgAV, revealed perivascular GD-IgA1 deposition. The average GD-IgA1 concentration in serum was significantly higher in systemic IgAV than in skin-limited IgAV, despite overlap between the groups.<BR><B>CONCLUSIONS: </B>Although high GD-IgA1 levels may be predictive of systemic IgAV, patient numbers were too low to determine cutoff values for systemic versus skin-limited IgAV.<BR><B>CONCLUSIONS: </B>Perivascular GD-IgA1 deposition is a prerequisite for systemic and skin-limited IgAV; however, high GD-IgA1 levels in some patients with systemic IgAV suggest a dose-dependent effect of GD-IgA1 in IgAV.