Gastrointestinal bleeding is associated with renal prognosis in adult patients with IgA vasculitis with nephritis

BACKGROUND: Although the prediction of renal prognosis in patients with IgA vasculitis with nephritis (IgAVN) is important, the association between gastrointestinal bleeding (GIB) and its renal prognosis is unknown. This study investigated the effect of GIB on the progression to end‐stage kidney disease (ESKD) in patients with IgAVN. METHODS: We compared the clinicopathological findings at diagnosis, therapy, and clinical outcomes between 10 patients with GIB and 20 patients without GIB in 30 patients with IgAVN aged ≥18 years at the renal biopsy. The primary outcome was the incidence of ESKD. Secondary outcomes included clinical remission and all‐cause mortality. The outcomes and factors affecting the progression to ESKD were evaluated using the Kaplan‐Meier method with log‐rank test and Cox proportional hazards models. RESULTS: End‐stage kidney disease, clinical remission, and deaths from any related cause occurred in 6, 17, and 2 patients, respectively. In Kaplan‐Meier analyses, the GIB group showed a higher incidence of ESKD (50% vs 5%, P = .003) and a lower incidence of clinical remission (20% vs 75%, P = .003). Although the numbers were not statistically significant, this group tended to have a greater number of deaths than the non‐GIB group (7% vs 0%, P = .07). In a multivariable Cox model adjusted for hypertension and urinary proteinuria, GIB could not demonstrate a significant association with ESKD (hazard ratio, 4.51; 95% confidence interval, 0.39‐52.7; P = .23). CONCLUSION: IgAVN with GIB has worse renal outcome, but GIB does not have a statistically significant association with progression to ESKD.