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Kidney Week

Abstract: TH-PO669

Effective Treatment of Renal Thrombotic Angiopathy due to Idiopathic Multicentric Castleman Disease with Rituximab

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Doppalapudi, Hima B., UMass Memorial Health, Worcester, Massachusetts, United States
  • Caraballo, Luis B., UMass Memorial Health, Worcester, Massachusetts, United States
  • Vanguri, Vijay K., UMass Memorial Health, Worcester, Massachusetts, United States
  • Ralto, Kenneth M., UMass Memorial Health, Worcester, Massachusetts, United States
Introduction

Idiopathic multicentric Castleman disease (iMCD) is a rare, benign lymphoproliferative disorder. Renal involvement in iMCD is uncommon but is usually associated with thrombotic microangiopathy, and effective therapies have not been rigorously studied. First-line therapy includes steroids and monoclonal antibodies targeting IL-6. We present a case of iMCD with renal involvement unresponsive to siltuximab but responsive to rituximab.

Case Description

A 36-year-old gentleman presented with shortness of breath, edema, lymphadenopathy, and fevers and was found to have a serum creatinine (sCr) of 2.5 mg/dL. Urine sediment showed muddy brown casts and he had subnephrotic range proteinuria. A renal biopsy showed acute microangiopathy with diffuse glomerular endotheliosis and minimal fibrosis. A subsequent inguinal lymph node biopsy showed reactive lymphoid hyperplasia with some changes suggestive of Castleman disease. He was initiated on steroids and sCr improved to 0.94 mg/dL. One year after the initial presentation, he was re-admitted with dyspnea and acute kidney injury (AKI). A repeat renal biopsy showed chronic angiopathic changes accompanied by scattered endotheliosis and mild fibrosis, and he was placed on a prednisone taper with improvement in his renal function. Given his recurrent disease, he was started on siltuximab and received 3 doses. He failed to respond to this and was transitioned to rituximab with subsequent resolution of his AKI, proteinuria, and lymphadenopathy.

Discussion

Renal involvement in severe cases of iMCD is rare but is usually associated with microangiopathy and endothelial injury; however, little is known about the most effective treatment. Siltuximab is often the first-line therapy, but there is limited data for patients who do not respond. Second-line therapies include chemotherapy, immunomodulators, and immunosuppressants. Our case demonstrates improvement in renal function and resolution of proteinuria with rituximab.