Tuberculosis and pauci-immune crescentic glomerulonephritis

We report here a case that highlights tuberculosis (TB) as a possible cause for pauci-immune crescentic glomerulonephritis (c-GN), an important and often treatable cause of kidney injury. A 47-year-old HIV-negative man of mixed ethnicity presented with a 2-week history of cough, haemoptysis and unintentional weight loss. Chest examination revealed crepitations over the right upper zone and urinalysis demonstrated an active urinary sediment with red cell casts. Chest radiograph confirmed right upper lobe cavitation. Serum laboratory investigations revealed a serum creatinine of 632 µmol/L and were negative for antineutrophil cytoplasmic antibodies. A diagnosis of pauci-immune c-GN was made on renal biopsy. In addition, sputum PCR confirmed infection with drug-sensitive Mycobacterium tuberculosis . Standard TB treatment and immunosuppression with prednisone and cyclophosphamide was commenced, and over the course of 6 months, renal function improved to an estimated glomerular filtration rate >60 mL/min.