2020 Volume 32 Issue 3 Pages 238-244
We report a case of severe consumption thrombocytopenia after tocilizumab（TCZ）administration. The patient was a 66-year-old Japanese woman with rheumatoid arthritis diagnosed at 20 years of age. Owing to exacerbation of her condition, intravenous TCZ was administered in July 2018. However, 12 days later, she visited our department because of petechiae on both legs. Her blood platelet count markedly decreased from 340,000/µl（before administration）to 6,000/µl（after administration）, and she was hospitalized on the same day. On the day of hospitalization, intravenous immunoglobulin infusion and prednisolone（50 mg/day）administration were initiated together with platelet transfusion. The thrombocyte corrected count increment at approximately 24 h after the initial platelet transfusion was 2511/µl, suggesting increased platelet destruction. The platelet count gradually improved and recovered to 340,000/µl on day 8 of hospitalization. The laboratory findings revealed elevated platelet-associated Immunoglobulin G and immature platelet levels. Bone marrow puncture revealed that both erythroid and granulocytic series were normal in terms of number and morphology, and her megakaryocyte levels were mildly increased. Based on the clinical course and these findings, drug-induced immune thrombocytopenia caused by TCZ was suspected. Consumption thrombocytopenia can occur after TCZ administration.
