[A case of pulmonary tuberculosis complicated with severe thrombocytopenia during treatment].

A 58-year-old man was hospitalized with dyspnea. His sputum tested positive for acid-fast bacilli, and PCR analysis revealed Mycobacterium tuberculosis. After the initiation of treatment with isoniazid, rifampicin, ethambutol, and pyrazinamide, the patient developed severe thrombocytopenia. The thrombocytopenia persisted even after the discontinuation of all antituberculosis drugs, and hence, the patient was given blood transfusion. Later, it was found that the patient's platelet-associated IgG level was high, and bone marrow aspiration revealed the presence of megakaryocytes with lesser degree of platelet adhesion. Considering that the patient's thrombocytopenia was induced by an immunological mechanism, he was administered prednisolone; this resulted in the resolution of thrombocytopenia. The patient successfully completed the tuberculosis treatment. Clinicians should remember that antituberculosis drugs may induce autoimmune thrombocytopenia, and if they experience such a case, they should report it to share information, including the names of possible offending drugs.