SARS-CoV-2ワクチン接種後のSBT/ABPC投与患者に生じた免疫性血小板減少症の1例

抄録

Immune thrombocytopenia （ITP） is an acquired autoimmune disease caused by antibody production against platelet-associated antigen. Recently, the onset of ITP after novel coronavirus （SARS-CoV-2） vaccination has been increasingly reported. We report a patient who received antibiotics （SBT/ABPC） after SARS-CoV-2 vaccination, and newly developed ITP through a rapid decrease in the platelet count. The patient was a 25-year-old female after SARS-CoV-2 vaccination. Due to acute purulent periostitis of the mandible, incision of an abscess was performed. Petechia and a rapid decrease in the platelet count （7,000/μl） were observed 2 days after the start of SBT/ABPC administration. Under a tentative diagnosis of drug-induced thrombocytopenia, drug administration was discontinued and platelet transfusion was performed. However, there was no response. Bone marrow biopsy did not show any abnormal findings, leading to a diagnosis of ITP. High-dose intravenous immunoglobulin/steroid combination therapy was started, resulting in prompt recovery of the platelet count. Concerning the etiological factor responsible for the decrease in the platelet count in the present case, it was difficult to differentiate drug （antibiotic）-induced thrombocytopenia from the incidental onset of ITP. Furthermore, the patient had received SARS-CoV-2 vaccination 15 days before the onset of ITP, suggesting a vaccination-related ITP onset. Serious thrombocytopenia may induce complications, such as abnormal hemorrhage, leading to a fatal outcome. Considering the prompt discontinuation of drug administration/switching and the possibility of ITP onset, it may be important to establish a system for close cooperation among medical departments so that prompt, adequate systemic management may be performed.