Kidney involvement in idiopathic multicentric Castleman disease–TAFRO syndrome: clinical spectrum, pathology and outcomes

Abstract

ABSTRACT Background Idiopathic multicentric Castleman disease–thrombocytopenia, anasarca, myelofibrosis, renal dysfunction and organomegaly syndrome (iMCD-TAFRO) is a clinically aggressive subtype. Renal involvement and its impact on prognosis are poorly characterized. We aimed to describe renal clinicopathological features and outcomes in a large iMCD-TAFRO cohort. Methods This 10-year retrospective cohort study enrolled iMCD-TAFRO patients at Peking Union Medical College Hospital. Renal involvement was defined by iMCD consensus criteria. Survival was analyzed using Kaplan–Meier methods. Results A total of 48 patients (70.8% male; mean age 45 ± 15 years) were included. Renal involvement was observed in 95.8% (46/48) of the patients, presenting predominantly with reduced urine output, mild hematuria and proteinuria, as well as elevated serum creatinine. Acute kidney injury (AKI) occurred in 80.4% (37/46) of patients showing renal involvement and 37.8% of them required renal replacement therapy. Renal biopsies (n = 7) revealed glomerular microangiopathy in six cases. AKI was associated with elevated C-reactive protein (CRP) and D-dimer levels, and CRP levels correlated with peak serum creatinine levels. Therapy targeting the iMCD was mainly bortezomib, cyclophosphamide and dexamethasone regimen (31/48, 64.6%) with/without anti-interleukin-6 therapy. Nine patients died within hospital or during follow-up. Among AKI patients, 28/37 (75.7%) showed full recovery of renal function. Despite worse renal function at baseline, no significant survival difference was observed between dialyzed and non-dialyzed patients. Conclusions Renal involvement in iMCD-TAFRO is common and frequently manifests as AKI associated with systemic inflammation. Early and aggressive therapy combined with supportive renal care, including timely dialysis, improved renal recovery and overall prognosis.