In our patient, ADA was markedly elevated at 126.5 U/L and 100.0 U/L, with lymphocyte-predominant exudate, particularly when other causes, such as lymphoma, empyema, or autoimmune conditions, were excluded via cytology, histopathology, and autoantibody panels, which further supported the presumptive diagnosis of TPE. This evidence concerns the gene ADA and Autoimmunity.