A CASE OF CAST NEPHROPATHY PROBABLY ASSOCIATED WITH RIFAMPICIN THERAPY IN AN ADULT MALE WITH TB SPINE

In developing countries, where tuberculosis is epidemic, acute kidney injury requires diagnostic renal biopsy and prognostication. A 60 year old male, hypertensive with left ventricular dysfunction, presented with non ST elevation myocardial infarction. Previously, he had been diagnosed Potts spine and was treated with anti tubercular drugs, including rifampicin 600 mg for 7 months. Investigations revealed blood urea nitrogen 12.20 mmol/L, serum creatinine 247.52 micromol/L, urine albumin 1+, with no sediments. Ultrasound abdomen showed normal sized kidneys. As he had rapidly worsening renal function over the next 7 days with blood urea nitrogen 23.20 mmol/L, creatinine 624.98 micromol/L, hemodialysis was initiated through a temporary jugular access, which was subsequently changed over to a continuous ambulatory peritoneal dialysis. As the patient continued to be dialysis dependant and oliguric, a renal biopsy done showed acute on chronic tubulointerstitial nephritis and cast nephropathy. Serum kappa was 2960 mg/L (3.3-19.4 mg/L), lambda 296 mg/L (5.71-26.3 mg/L), ratio 10(0.26-1.65), serum β2 microglobulin >20,000 ng/ml (670-2143 mg/ml), serum IgG 24.20 g/L (7-16 g/L) and IgA 5350 mg/L (700-4000 mg/L). In view of cast nephropathy, rifampicin was discontinued as suspected to be the most probable cause. Patient continued on peritoneal dialysis, with no renal recovery for 4 months, after which he had a cardiac arrest in hospital. Our patient is unique in that despite discontinuation of rifampicin, his acute kidney injury progressed to chronic kidney disease requiring dialysis and a cardiovascular death.