Clinical Significance of Persistent Hematuria Degrees in Primary IgA Nephropathy: A Propensity Score-Matched Analysis of a 10-Year Follow-Up Cohort

The clinical significance of persistent hematuria degrees has not been expounded in primary IgA nephropathy (IgAN) and requires further research.From January 2003 to May 2022, a total of 684 IgAN patients with persistent hematuria were enrolled to conduct a retrospective single-center study. Patients whose hematuria degree at baseline was higher than the second tertiles of the whole were included in the high-degree hematuria cohort (Hh), and the low-degree hematuria cohort (Lh) was constructed with 1:1 matched cases from the rest according to age, gender, and estimated glomerular filtration rate (eGFR) at baseline and follow-up time. Survival was determined using the Kaplan-Meier method (K-M) and generalized linear mixed-effects model (GLMM). Risk factors for survival were determined according to the Cox proportional hazards model.Both the Hh and Lh consisted of 228 cases. While the demographic data and the renal function at baseline were matched, both the K-M (p = 0.02) and GLMM (p = 0.04) proved that the prognosis of the Hh was significantly worse than that of the Lh within 10 years of follow-up. The higher persistent hematuria degree was an independent risk factor (3.93; 95% confidence interval, 1.33-11.6) associated with reaching the endpoint (eGFR decreased from the baseline ≥30% continuously or reached end-stage renal disease [ESRD]). The Hh had a significantly higher proportion of crescent (p = 0.003). The prognosis of the Hh was significantly worse than that of the Lh when accompanied by the crescent and presented an indistinct difference if the crescent was absent.The clinicopathologic manifestation of IgAN patients with persistent high-degree hematuria was severer, and the prognosis was worse than those with persistent low-degree hematuria.