Pattern of renal amyloidosis in Indian patients

Two hundred and thirty-three patients with renal amyloidosis were studied in an attempt to identify the incidence and pattern of the disease in northern India. The incidence of amyloidosis was 1.01% of 6431 post-mortems and 8.4% of 1980 renal biopsies from patients who presented with clinical evidence of glomerular disease. Two hundred and three patients (87.1%) had secondary amyloidosis, 22 (9.4%) had primary amyloid and 8 patients (3.5%) had amyloidosis associated with multiple myeloma. Tuberculosis of various organs was the commonest predisposing disease accounting for 59.1% of secondary amyloidosis, followed by chronic suppurative lung disease in 24.1%. Rheumatoid arthritis, chronic osteomyelitis and lepromatous leprosy were seen in a small percentage of patients (2 to 8%). Proteinuria of varying degree was present in all the 233 patients and 12.9% of them had a daily protein excretion of more than 10 g. Post-mortem examination of 65 patients with renal amyloidosis showed that 75.3% also had amyloid deposit in the spleen, 63% in the liver, and 50.8% in the adrenals. Clinical evidence of disappearance of proteinuria was observed in 3 patients with secondary amyloidosis; in 2 of them, the regression of amyloidosis was confirmed by serial renal biopsy performed 3 and 5 years after the initial diagnosis.