HYPERTENSION IN IGA NEPHROPATHY WITH MICROANGIOPATHY

Abstract

Objective: Our study aimed to describe blood pressure (BP) in case of thrombotic microangiopathy (TMA) associated with primitive IgA nephropathy (IgAN), its correlation with histological lesions and its prognostic impact. Design and method: We reviewed files of IgAN patients admitted and followed-up in our department between 1980 and 2017. We included adults showing at least one TMA lesion at their biopsy. Patients with IgA vasculitis or secondary IgAN were excluded. Results: Fifty files were studied. IgAN was revealed by malignant hypertension (MH) in 42% of cases. At admission, 68% of patients were under antihypertensive treatment. Mean arterial pressure (MAP), systolic pressure (SP) and diastolic pressure (DP) were respectively 113, 155 and 93 mmHg. Hypertension was found in 96% of patients, and was graded 1, 2 and 3 in 32%, 40% and 28% of cases. Only 30 patients had initial cardiac ultrasound and eye fundus revealing hypertensive cardiopathy in 53% and hypertensive retinopathy in 47% of cases. Mean proteinuria was 3.2 g/day ± 1.8. Median serum creatinine was 310 μmol/L. SP was correlated to C2 crescents (p = 0.015); DP to M1 mésangial hypercellularity (p = 0.033) and PAM to S1 glomerulosclerosis and C2 crescents (p = 0.045; p = 0.023). Those lesions were associated with more severe hypertension. After biopsy, all patients received antihypertensive agents (2.22 drugs per person): 80% had calcic inhibitors and 62% had renin angiotensin system inhibitors. At six months, among the 26 patients not on dialysis, only three had controlled BP. Dialysis risk was associated with initial MAP > = 100 mmHg (p = 0.027; OR = 12) and initial MH (p = 0.007; OR = 7.7). This risk was correlated with a higher SP at six months: 146 mmHg if dialysis versus 132 mmHg if not (p = 0.043). Renal survival was significantly reduced for patients with initial grade 3 hypertension (log Rank p = 0.043). Conclusions: Hypertension is frequent and severe in IgAN associated with TMA. Renal prognosis would be poorer in case of malignant, severe or persistent hypertension.