Retrospective cohort study demonstrates that persistent severe hematuria at 6 months triples kidney failure risk in IgA nephropathy, indicating its value as an early prognostic biomarker.
Key Points
To evaluate whether hematuria status at 6 months after treatment initiation is independently associated with long-term kidney disease progression in patients with IgA nephropathy.
Conducted a single-center retrospective cohort study of 286 patients with biopsy-proven IgA nephropathy using a 6-month landmark analysis (median follow-up of 3.1 years).
Classified patients by 6-month urinary red blood cell (uRBC) count into remission (<5 RBC/HPF), persistent moderate (5–29 RBC/HPF), and persistent severe (≥30 RBC/HPF).
Evaluated a composite primary outcome of end-stage kidney disease or a ≥30% decline in estimated glomerular filtration rate using multivariable Cox models and restricted cubic splines.
The primary composite outcome occurred in 38 of 286 patients (13.3%) over the median 3.1-year follow-up period.
Persistent severe hematuria at 6 months was significantly associated with an increased risk of the primary outcome compared with remission (HR 2.97, 95% CI 1.33–6.67, P = 0.01).
Restricted cubic spline analyses revealed a continuous, graded association between higher uRBC counts at 6 months and worse kidney outcomes.