Renal thrombotic microangiopathy is associated with poor renal survival in children with immunoglobulin A nephropathy

The aim of this study was to examine the clinical and pathological characteristics as well as the prognosis of immunoglobulin A nephropathy (IgAN) accompanied by renal thrombotic microangiopathy (rTMA) in paediatric patients.

After balancing epidemiological characteristics and pathological types between groups, 427 patients (rTMA group: 23, non-rTMA group: 46) were included. The clinical and pathological features, prognosis and clinical risk factors of the two groups were analysed.

IgAN-rTMA children showed more severe clinical and pathological manifestations. The findings from the logistic regression analysis indicated that hypercellularity 1 (E1) (HR: 0.805, 95% CI: 0.763 ~ 1.452, P = .016), endocapillary proliferation (HR: 1.214, 95% CI: 0.093 ~ 4.815, P = .025) and C3 staining (HR: 7.554, 95% CI: 2.563 ~ 15.729, P = .037) were the risk factors for rTMA in children with IgAN. The renal survival in rTMA group was lower than non-rTMA group (χ² = 18.467, P = .000). Cox regression analysis showed that E1 (HR: 7.441, 95% CI: 1.095 ~ 10.768, P = .037), C3 disposition (HR: 3.414, 95% CI: 0.834 ~ 11.578, P = .027) and rTMA (HR: 8.918, 95% CI: 1.032 ~ 16.754, P = .041) were identified as independent risk factors for the development of end-stage renal disease (ESRD).

The presence of rTMA had a significant impact on the severity and prognosis of IgAN. And rTMA has been identified as an independent risk factor for the development of renal failure in children diagnosed with IgAN.