[Systemic Lupus Erythematosus with Marked Eosinophilia and Clinical Features Mimicking TAFRO Syndrome]

A 76-year-old woman was referred to our hospital because of fever, hemorrhagic skin lesion with pruritus, and severe thrombocytopenia. Anemia; marked eosinophilia; and elevated ALP, CRP, and soluble IL-2 receptor levels were observed on admission. Both anti-nuclear antibody and Coombs tests were positive. Computed tomography revealed bilateral pleural effusion, ascites, abdominal lymphadenopathy, and mild hepatosplenomegaly. A thorough examination for the initial differential diagnoses excluded the possibility of myeloid/lymphoid neoplasms with eosinophilia and gene rearrangement, infectious diseases, and eosinophilic granulomatosis with polyangiitis. Remaining possibilities included angioimmunoblastic T-cell lymphoma (AITL) and systemic inflammatory disorders. Although AITL was plausible, there was no histological evidence to support the diagnosis. The patient was then administered prednisolone alone, which led to a lasting resolution of her symptoms. The atypical AITL course raised the suspicion of a misdiagnosis; thus the possibility of an inflammatory disease was reconsidered. TAFRO syndrome was suspected owing to its characteristic clinical features (thrombocytopenia, anasarca, fever and organomegaly). Since a definitive diagnosis required the exclusion of systemic lupus erythematosus (SLE), anti-double-stranded DNA antibody was tested in the initial frozen serum sample. An unexpected positive result led to the final diagnosis of SLE. Here, we report a rare case of SLE lacking typical symptoms and exhibiting various hematological abnormalities, such as eosinophilia.