Patients with lepromatous leprosy, whether reactional or not, had a CD4/CD8 frequency of 2:1. However, in healthy volunteers (HVs) there was a 1:1 ratio of CD4/CD8, in addition to the change in the frequency of whole T cells, after in vitro stimulation by M. leprae. This same group showed an increased frequency of CD4 and CD8 + T lymphocytes, although the CD4/CD8 ratio did not change. The gene discussed is CD8A; the disease is lepromatous leprosy.