Introduction: Henoch-Schönlein Purpura (HSP) is a small-vessel vasculitis characterized by deposits of immunoglobulin A (IgA) in target tissues. HSP is more frequently seen in children and usually has benign and self-limiting renal involvement; however, it is estimated that up to 2% of children with HSP nephritis can develop End-Stage Renal Disease (ESRD) and require renal replacement therapy. Due to the infrequency of HSP causing ESRD, large-scale studies of HSP and kidney transplant (KT) outcomes are scarce.

Methods: We used data from Scientific Registry of Transplant Recipients to evaluate differences for HSP patients listed for KT. Adult and pediatric patients listed from October 1987 to April 2021 were included. Recipients without HSP were randomly selected and matched in a 3:1 ratio to HSP recipients according to age (exact year), gender, ethnicity, donor source (living versus deceased), and year of transplantation (±3 years). Inferential statistics were used to evaluate differences between HSP and non-HSP patients. Regression modeling using a forward conditional approach and Kaplan-Meier survival analysis with a Mantel-Cox log-rank test were performed to calculate survivals and compare outcomes.

Results: During the study time period, 504,878 KT were performed; 893 (0.17%) were for HSP. Compared with non-HSP patients, HSP KT recipients were younger (30.6±14.2vs 47.2±15.8; p<0.001) and more commonly Caucasian (87.5% vs 68.6%; p<0.001), received a living donor allograft (44.5 vs 32.9; p<0.001), and female (45.3% vs. 39.5%, p=0.001). Most HSP KT patients were preemptive (79.8%). A total of 773 HSP recipients were matched to 2,319 non-HSP recipients. For HSP patients, 1-, 3-, and 5-year death-censored graft survival (DCGS) was 87.3%, 70.4%, and 53.3%, respectively. For matched non-HSP patients, DCGS was 86.9%, 70.2%, and 52.5%, respectively (all p>0.05). Overall patient survival for HSP patients was 89.8%, 72.4%, and 55.6% at 1, 3, and 5 years, respectively. Overall patient survival for matched non-HSP patients was 89.3%, 72.9%, and 55.4% at 1, 3, and 5 years, respectively (all p>0.05). Acute rejection and graft thrombosis were the two leading causes of graft loss for both HSP (28.6% and 19.0%, resp.) and non-HSP patients (18.8% and 31.6%, resp.). In HSP patients who did not suffer recurrence, 1-, 3-, 5-, and 10-year DCGS was 95.8%, 88.8%, 81.3%, and 64.0%, respectively. Using regression model analysis of HSP KT patients for recurrence, older age (OR, 95% CI 1.05, 1.03-1.07, p<0.001) was significantly associated with recurrence; while a living donor allograft (0.50, 0.32-0.79, p=0.003) and a higher BMI (0.95, 0.91-0.99, p=0.020) were protective.

Conclusion: In a contemporary cohort of HSP KT patients, we demonstrate comparable graft and patient survival for HSP patients, compared to matched non-HSP patients, and superior survival if recurrence can be avoided.