Kidney histology and clinical correlates in malignant hypertension

In this clinico-pathologic study, post-mortem kidney material from 30 cases with malignant hypertension (MHT) defined as severe hypertension with bilateral retinal haemorrhages and exudates (grade III retinopathy) with (grade IV retinopathy) or without papilloedema, were studied. Mucoid intimal proliferation (MIP) in interlobular artery and ischaemic collapse of the glomerular tufts occurred in all cases, whereas fibrinoid necrosis (FN) was seen in only 24 (80%) of the cases. FN was not correlated nor associated with sex, age, blood pressure, retinopathy or serum creatinine. Tubular atrophy and interstitial fibrosis occurred in 24 (80%) and correlated best (rS = 0.8, p < 0.05) with serum creatinine in comparison to glomerular sclerosis (rS = 0.6, p = n.s), fibrinoid necrosis (rS = 0.49, p = n.s) and epithelial crescents (rS = 0.43, p = n.s). This study provides histologic evidence of lack of difference between grades III and IV retinopathy, shows MIP as the more characteristic vascular lesion in MHT and also, good correlation between renal function and tubulointerstitial involvement.