TAFRO Syndrome in Disguise: A Case of Idiopathic Multicentric Castleman Disease-Like Syndrome with Renal Thrombotic Microangiopathy and Autoimmune Overlap

Introduction: TAFRO syndrome is a rare systemic inflammatory disorder characterized by thrombocytopenia, anasarca, fever/elevated CRP, reticulin fibrosis/renal dysfunction, and organomegaly. It is considered an aggressive subtype of iMCD, requiring lymph node (LN) biopsy for definitive diagnosis. The cases lacking LN biopsy but meeting all the criteria for iMCD and TAFRO are categorized as TAFRO with possible iMCD. Another well recognized category is TAFRO associated with autoimmune diseases, Sjögren's syndrome. Case Description: We present a 29-year-old female patient with a history of rheumatoid arthritis and Sjögren’s syndrome who presented with thrombocytopenia, anasarca, high CRP, renal failure, hepatosplenomegaly, and retroperitoneal lymphadenopathy, 3 weeks after a viral illness. She required drainage of pleural effusions and ascites. Noted to have elevated sIL-2R, IL-6, and anti-SSA levels, negative HHV-8, and normal ADAMST 13 and complement levels. Bone marrow (BM) biopsy showed reticulin fibrosis. A LN biopsy was not feasible. Renal biopsy showed thrombotic microangiopathy (TMA). Hence, a diagnosis of ‘TAFRO syndrome with possible iMCD’ with autoimmune overlap was entertained. She responded well to systemic corticosteroids, plasmapheresis, and anakinra. She was stable on discharge with improved renal function. Post-discharge, regimen was changed to anti-IL6 therapy, sarilumab. Discussion: This case emphasizes the importance of recognizing TAFRO syndrome even without LN biopsy and further highlights its diagnostic complexity and the co-occurrence of renal TMA and autoimmune overlap. Prompt diagnosis and early immunosuppressive therapy are critical to improve systemic and renal outcomes in these diagnostically ambiguous presentations. Treatment options are glucocorticoids, IL-6 inhibitors (tocilizumab/siltuximab), anti-IL-1 drugs (anakinra/ canakinumab), along with supportive care.BM biopsy with reticulin fibrosis