Epstein-Barr Virus-Encoded RNA-Positive Lymphocytes in Bone Marrow and Lymph Nodes in an Autopsy Case of TAFRO Syndrome.

A 55-year-old man was admitted to the hospital with vomiting, diarrhoea, and chest pain. Upon examination, he exhibited signs of increased inflammatory response, acute kidney injury, and thrombocytopenia, leading to a diagnosis of TAFRO syndrome, which was supported by the clinical evidence of generalized lymphadenopathy, pleural effusion, and hepatosplenomegaly. Despite receiving intensive multimodal immunosuppressive therapy, including glucocorticoid pulse therapy (methylprednisolone 1,000 mg/day), tocilizumab, and cyclosporine in the intensive care unit, the patient showed minimal response and succumbed to the disease on the seventh day of hospitalization. Histopathological analysis of the lymph nodes revealed idiopathic multicentric Castleman disease (iMCD)-like features, and Epstein-Barr virus-encoded RNA (EBER) in situ hybridization identified multiple EBER-positive cells. These findings highlight the elusive pathogenic mechanism of TAFRO syndrome and the potential resistance of some patients to standard treatments such as tocilizumab. The presence of EBER-positive cells in lymph nodes or bone marrow may serve as an indicator of disease severity and treatment resistance. Therefore, histopathological detection of EBER-positive cells may help predict responsiveness to conventional treatments, disease severity, and prognosis in patients with TAFRO syndrome.