Les atteintes uro-néphrologiques au cours de la maladie associée aux IgG4

Hyper-IgG4 syndrome, or IgG4-related disease, is an emerging disorder, involving one or more organ(s), and characterized by “storiform” fibrosis and inflammatory lesions with a predominance of IgG4+ plasma cells and increased IgG4 serum levels. Since the first report of auto-immune pancreatitis, numerous organ lesions have been reported and have been found to occur in a same patient including: sialadenitis, dacryoadenitis, lymphadenopathy, liver and biliary tract involvement, and renal and retroperitoneal lesions. Renal involvement was first described in 2004 and usually presents as functional and/or morphological abnormalities. In most cases, renal pathological analysis reveals tubulointerstitial nephritis that is rarely associated with glomerular lesions. Retroperitoneal fibrosis is also a typical feature that may be associated with periaortitis or inflammatory abdominal aortic aneurysm. First line treatment is based on corticosteroid therapy. Short-term outcome is usually favorable. However, patients should be carefully monitored for relapses and long-term complications. Although the multiple organ lesions share common clinical, biological, radiological and pathological features, no consensus diagnostic criteria have yet been validated for IgG4-related disease. Ruling out differential diagnoses is thus mandatory. Our literature review provides nephrologists, urologists and pathologists with key elements that will help in the early diagnosis and proper management of this new and emerging disorder.     

Une artérite à cellules géantes révélatrice d’un syndrome de Goodpasture

Goodpasture's syndrome is a triad of anti-glomerular basement membrane (anti-GBM) circulating antibodies, glomerulonephritis and pulmonary hemorrhage. We reported a 65-year-old woman with headaches, asthenia and weight loss. Giant cell arteritis was confirmed by temporal artery biopsy. The patient had associated renal condition with moderate acute renal failure, proteinuria and haematuria. Renal biopsy showed extracapillary glomerulonephritis and linear staining of immunoglobulins G along glomerular basement membrane. There was no clinical pulmonary involvement. Anti-MBG antibody was positive and allowed Goodpasture's syndrome diagnosis. The patient was treated with corticoids and cyclophosphamide. Patient's condition and renal function improved quickly and anti-MBG antibodies became negative. Goodpasture's syndrome may be characterized by isolated renal expression without pulmonary involvement. We described for the first time association of Goodpasture's syndrome with giant cell arteritis.