Association of anti-glomerular basement membrane antibody disease with dermatomyositis and psoriasis: case report

context: anti-glomerular basement membrane (anti-gbm) antibody syndrome is characterized by deposition of anti-gbm antibodies on affected tissues, associated with glomerulonephritis and/or pulmonary involvement. this syndrome has been described in association with other autoimmune disorders, but as far as we know, it has not been described in association with dermatomyositis and psoriasis. case report: a 51-year-old man with a history of dermatomyositis and vulgar psoriasis presented with a condition of sensitive-motor polyneuropathy of the hands and feet, weight loss of 4 kg, malaise and fever. on admission, he had been making chronic use of cyclosporin and antihypertensive drugs for three months because of mild arterial hypertension. laboratory tests showed anemia and leukocytosis, elevated serum urea and creatinine and urine presenting proteinuria, hematuria, leukocyturia and granular casts. the 24-hour proteinuria was 2.3 g. renal biopsy showed crescentic necrotizing glomerulonephritis with linear immunoglobulin g (igg) deposits on the glomerular basement membrane by means of direct immunofluorescence, which were suggestive of anti-gbm antibodies. the patient was then treated initially with methylprednisolone and with monthly cyclophosphamide in the form of pulse therapy.