Kidney Biopsy-Proven Malignant Hypertension in South Africa: The Impact of Underlying Glomerulonephritis on Clinical Features and Survival

Background Malignant hypertension is a medical emergency that frequently causes kidney damage. In sub-Saharan Africa (SSA), it continues to impose a substantial morbidity and mortality burden. Despite its clinical importance, data from SSA remain scarce. Materials and Methods In this retrospective case series of adults with biopsy-confirmed malignant hypertension admitted between 1990 and 2022, we characterized the clinical and renal histopathological features of malignant hypertension and assessed their relationship with kidney and patient outcomes. We also compared these features between patients with and without underlying glomerulonephritis (GN). Results Forty-five patients were included. The mean age was 37 years, and three-quarters were male. At admission, mean systolic blood pressure was 204 ± 33 mmHg, diastolic blood pressure was 124 ± 23 mmHg, serum creatinine was 972 µmol/L (IQR 535–1287), and proteinuria was 3.8 g/d (IQR 1.3–6.6). GN was identified in 36% of cases. Key differences included significantly larger kidneys ( p <0.001) and higher serum potassium levels ( p = 0.007) in patients with GN, whereas those without GN had more frequent ischemic wrinkling of the glomerular basement membrane ( p = 0.002). Kidney recovery was very poor, with only one patient (2%) regaining kidney function. Overall, in-hospital mortality was high at 39%. Conclusions Malignant hypertension primarily affected young adult males and was characterized by severe kidney dysfunction, poor renal recovery, and high in-hospital mortality. Underlying glomerular disease was associated with the worse survival.