Additional investigations showed elevated angiotensin-converting enzyme (ACE) and β2-microglobulin, while inflammatory markers, autoantibodies, and infectious serologies, including HIV, hepatitis B and C, Epstein-Barr virus (EBV), cytomegalovirus (CMV), syphilis, toxoplasmosis, and atypical viruses, were negative (Table 2). This evidence concerns the gene ACE and syphilis.