One Case of Abnormal Decrease of Interferon Gamma Release Assay Result Caused by Melphalan.

Background: Interferon gamma release assay (IGRA) is an important method to detect the specific antigen of tuberculosis, which is crucial to the diagnosis of tuberculosis or potential tuberculosis infection.
Methods: We report a case of myelosuppression caused by the use of Melphalan in the treatment of multiple myeloma, resulting in an abnormal decrease in interferon gamma release assay results.
Results: We collected blood samples from the patient for retesting and the result of the test did not differ significantly. Upon reviewing the case, it was found that the patient's use of Melphalan treatment resulted in bone marrow suppression and extreme reduction of peripheral blood lymphocytes. Therefore, it is speculated that the abnormal decrease of the interferon gamma release assay result is caused by bone marrow suppression, which is caused by the use of Melphalan.
Conclusions: When patients with multiple myeloma are treated with Melphalan, it can lead to bone marrow suppression and result in false negative interference gamma release assay results. Laboratory staff should consider the existence of such interference and communicate with clinical doctors in a timely manner.