リウマチ様関節炎に対する免疫抑制療法中に発症した成人T細胞性白血病/リンパ腫の1例

A ６４-year-old woman presented with lower leg edema, fever, and bilateral joint pain, involving the wrists, fingers, and knees, in April ２０１X. Serological test results were negative for rheumatoid factor, antinuclear antibody, and anti-cyclic citrullinated peptide antibody. A diagnosis of remitting seronegative symmetrical synovitis with pitting edema syndrome, a type of seronegative rheumatoid arthritis, was made and prednisolone was administered. The joint pain was refractory to prednisolone therapy. In February, ２０１X＋２, the patient presented with right cervical lymphadenopathy. The CT scan revealed swelling of the cervical, axillary, and inguinal lymph nodes bilaterally and rapidly enlarged. In April, １８F-fluorodeoxyglucose PET/CT scan showed an abnormal collection in the enlarged lymph nodes. The patient subsequently developed hoarseness with dyspnea and attended our department. Blood test results showed high levels of lactate dehydrogenase （５４７U/L） and soluble interleukin‐２ receptor （３４２００ IU/L） and were positive for anti-human T-cell leukemia virus type１ （HTLV‐１） antibody. Biopsy of the right cervical lymph node showed proliferation of abnormal lymphoid cells positive for CD３, CD４, and CD２５ and negative for CD７. Monoclonal integration of HTLV‐１ proviral DNA was detected in the lymph node. A diagnosis of adult T-cell leukemia/lymphoma （ATLL）, lymphoma type was made. The pain involving multiple joints was attributed to HTLV‐１associated arthropathy. Immunosuppressive therapy for HTLV‐１ carrier status may have played a role in the development of ATLL.