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Cutaneous vasculitis and glomerulonephritis associated with C4 deficiency
Author(s) -
Kosaka S.,
Osada S.,
Kaneko T.,
Nishimura S.,
Kawana S.
Publication year - 2013
Publication title -
clinical and experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 78
eISSN - 1365-2230
pISSN - 0307-6938
DOI - 10.1111/j.1365-2230.2012.04423.x
Subject(s) - medicine , mesangium , vasculitis , pathology , biopsy , skin biopsy , dermis , renal biopsy , purpura (gastropod) , mesangial proliferative glomerulonephritis , henoch schonlein purpura , glomerulonephritis , kidney , biology , disease , ecology
Summary Complete deficiency of the fourth component of complement (C4) is an extremely rare condition. However, it has been reported that partial C4 deficiency can occur in normal subjects, and is associated with several immune diseases. We report a 44‐year‐old woman who developed slight oedema and punctate purpura on her lower legs after a common cold. She was noted to have persistent microscopic haematuria and proteinuria, and her C4 level was undetectable. On histological examination of a skin biopsy specimen, leucocytoclastic vasculitis was seen, with granular deposition of IgG, IgM, C3 and C1q on the vessel walls in the upper dermis. A renal biopsy showed mild mesangial proliferative glomerulonephritis with slight damage to the capillary loops, and granular deposits of IgM and C4 mainly in the mesangium. The patient was systemically well and needed no medication. The C4 level remained low during the observation period, but neither genotyping nor allotyping analysis identified a C4 deficiency.