Association between lepromatous leprosy and Australia antigen

Australia antigen is more common in patients with lepromatous leprosy than in patients with tuberculoid leprosy or in non-leprosy controls. In the combined populations, the frequency is, in general, higher in males than females, and in younger people than in older people. Australia antigen has now been found to be associated with lepromatous leprosy, leukaemia, and hepatitis, and to cluster in families. It is sugegsted that indivuduals with Australia antigen have an inadequate immune response and are especially susceptible to various illness, including lepromatous leprosy.