Renal disorders in patients with collagen vascular diseases

Membranous nephropathy, mesangial proliferative glomerulonephritis and renal amyloidosis are common renal pathology in RA patients. However, IgA nephropathy and diffuse thinning of glomerular basement membrane are described as common and characteristic renal lesions in Japanese RA patients. Glomerular filtration rate may decrease significantly in active lupus nephritis, but renal plasma flow does not change or even increase. These findings seem to be characteristic of SLE patients with active renal disorders. Therefore, filtration fraction may be a useful clinical parameter to evaluate SLE patients. Scleroderma renal crisis(SRC) has been believed to be the most serious renal disorder in systemic sclerosis (SSc). Recently, the presence of an antibody to RNA polymerase has been associated with a high prevalence of SRC.