RESUMO
BACKGROUND: Urinary tract infection (UTI), especially pyelonephritis when inadequately treated may culminate in end-stage renal disease. The study aims to evaluate the risk factors for and clinico-pathologic features of chronic pyelonephritis (CPN) among patients in Aminu Kano Teaching Hospital, Kano, in North-Western Nigeria. MATERIALS AND METHODS: Data on cases diagnosed as CPN between 2010 and 2017 in the study centre were retrieved from archives and analysed for risk factors and clinic-pathologic features. RESULTS: Forty-three cases of CPN were diagnosed in the study period and comprised 24 males and 19 females, with a male: female ratio of 1.3:1. The ages ranged from 3 to 80 years with a mean age of 37.0 ± 19.6 years. Urinary tract obstruction, poorly treated UTI, HIV infection and polycystic kidney disease were the risk factors in 21 (49%), 15 (35%), 6 (14%) and 1 (2%) cases, respectively. Proteinuria was seen in 10 (23.3%) of the patients, hypertension in 7 (16.3%) and haematuria in 3 (7.0%) of cases. Nephrectomy was done in 17 (39.5%) of the 43 CPN cases, indications for surgery were pus-filled, non-functioning kidneys. The diameters of the removed kidneys ranged from 10 to 28 cm and they weighed between 140 g and 2500 g. Scarring, reported in 79.0% of patients, was the most common pathological finding, followed by pus casts in 48.8% and focal segmental glomerulosclerosis in 27.9%. No statistically significant difference was found between age or gender and aetiology or risk factors of the disease (P > 0.05). CONCLUSION: CPN with pus-filled and non-functioning kidneys is a common indication for nephrectomy. Urinary tract obstruction, poorly treated UTI, and HIV infection were major risk factors seen in this environment. To prevent this complication there is a need for better training of clinicians in the diagnosis and adequate treatment of UTI.