Rapidly progressive glomerulonephritis in a patient with renal amyloidosis: Case report and review of the literature
A 50-year-old man presented with the complaint of swelling of feet and facial puffiness of 1 month duration accompanied by oliguria. There was no hematuria or turbid urine. There was no history of exertional breathlessness or orthopnea. His appetite was fairly well preserved and his bowel movements were regular. He was not a diabetic or hypertensive and had no significant illness in the past.\nOn examination, he had pallor, pitting pedal edema, and facial puffiness. His blood pressure was 120/80 mmHg. Respiratory system examination revealed bilateral basal crepitations. Abdominal examination showed the presence of ascites without any evidence of organomegaly. Laboratory examination showed hemoglobin of 10 mg/ dL, total leukocyte count of 14.4 × 109/L with 76% of polymorphs in differential count. Biochemical parameters were as follows: random blood sugar 127 mg/dL, serum creatinine 1.4 mg/dL, blood urea 34 mg/dL, and serum albumin 0.9 g/dL. Serum electrolytes and liver function tests were normal. Erythrocyte sedimentation rate was 140 mm/h. Urine analysis showed 3+ protein, 2–3 pus cells/hpf, and inactive sediments. Urine protein creatinine ratio was 4.6 g/g. Chest X-ray showed bilateral pleural effusion. Abdominal sonogram showed moderate ascites with bilateral pleural effusion and bilateral normal-sized kidneys.\nSerum protein electrophoresis showed normal pattern lacking “M-spike.” Renal biopsy was carried out to ascertain the nature of glomerular pathology. Light microscopy showed 24 glomeruli, all of which showed pale, eosinophilic, acellular, weakly periodic acid-Schiff (PAS)-positive material in the mesangium and basement membrane, focally forming nodules []. Congophilia and apple-green birefringence were documented. There was no interstitial fibrosis or tubular atrophy. Minimal amount of amyloid material was seen in the wall of interlobular arteries. Immunofluorescence showed ten viable glomeruli that were negative for IgG, IgA, IgM, C3c, C1q, and fibrin. Immunohistochemical studies were positive for amyloid A protein in the deposits []. There was no light chain restriction. Bone marrow examination and skeletal profile ruled out plasma cell dyscrasia. Serum rheumatoid arthritis (RA) factor was negative. A diagnosis of renal amyloid A (AA) amyloidosis causing secondary nephrotic syndrome was reached and the patient was put on enalapril, atorvastatin, and diuretics. He was also initiated on colchicine 1.2 mg/day.\nHe returned for follow-up after 1 month with complaints of anorexia, nausea, and oliguria. He had discontinued treatment 3 weeks before. On evaluation, he had anasarca and had blood pressure of 130/80 mmHg. Clinically, the patient had persisting bilateral pleural effusion and ascites. Laboratory tests were as follows: hemoglobin 6.5 g/dL, blood urea 157 mg/dL, serum albumin 1.8 g/ dL, and serum creatinine 6.5 mg/dL. Urine analysis showed 3+ protein and 10–12 RBCs/hpf. RBC casts and granular casts were seen. Doppler study ruled out renal vein thrombosis. Antineutrophil cytoplasmic antibody (by immunoblot assay) was negative and serum C3 was 93.8 mg/dL (normal, 90–180 mg/dL). Considering the rapid deterioration of renal function and sudden drop in hemoglobin, renal biopsy was repeated. Fourteen viable glomeruli were seen on light microscopy, of which 30% of them showed active cellular crescents occupying circumferentially in addition to amyloid deposits []. There was no fibrinoid necrosis of the tufts. Vessel wall had minimal amyloid deposits and no area of necrotizing vasculitis was seen. Immunofluorescence showed eight viable glomeruli that were negative for IgG, IgA, IgM, C3c, C1q, and fibrin. There was no light chain restriction with kappa and lambda light chains.\nThe patient was treated with large doses of diuretics. Injectable methylprednisolone (1g) was given on three consecutive days. Inj. cyclophosphamide 500 mg was given. The patient gradually had increasing urine output and was symptomatically better at discharge, with serum creatinine improving to 3.5 mg/dL. Unfortunately, he was lost to follow-up.