Retrospective cohort evaluation of renal involvement in non-HIV castleman disease patients from a single academic center in Beijing, China.

Castleman disease (CD), a rare and clinically heterogeneous condition, frequently involves renal impairment, though this relationship remains poorly characterized. This large cohort study of 183 patients (116 unicentric [UCD], 67 multicentric [MCD]) investigated renal involvement (RI). RI occurred in 6.03% (7/116) of UCD and 55.22% (37/67) of MCD patients. In UCD-RI, 4 underwent renal biopsy, revealing varied pathological results, and 1 underwent total left nephroureterectomy. In MCD-RI, common manifestations included edema, nephrotic syndrome, and acute renal failure. Thrombotic microangiopathy (TMA) was the most frequent renal pathology (9/19 biopsies). Acute renal failure often responded well to treatment, with 60% (9/15) achieving complete recovery. The myeloma-like treatment regimen demonstrated superior efficacy compared to the lymphoma-like regimen and immunomodulatory therapy (P = 0.039). The 5-year renal survival rate in the MCD-RI group was 88.9%, not significantly different from UCD-RI (P = 0.45). Furthermore, the 5-year overall survival in the CD-RI group was 81.9%, showing no statistically significant difference from CD patients without renal involvement (P = 0.11). This study confirms that RI is more common in MCD, with TMA as a key pathological feature, and demonstrates that renal involvement does not negatively impact overall survival.