Serum immunoglobulin levels in tropical splenomegaly syndrome in New Guinea.

The serum levels of the immunoglobulins IgG, IgA and IgM were measured in 142 New Guinea natives with tropical splenomegaly syndrome, forty-two normal natives and twenty-four normal Caucasians. The mean levels of IgG and IgM were significantly elevated in all groups of natives. The highest levels of IgM occurred in natives with splenomegaly, with a wide range of values (150–3000 mg/100 ml). There were no significant differences in the levels of IgA or IgM between two groups of natives with splenomegaly from different regions, but the difference in IgG between the two groups was significant at the 5% level. No explanation was found for the significantly higher mean level of IgA in one group of native controls, compared with other groups of natives and Caucasians. The association of macroglobulinaemia with tropical splenomegaly syndrome in New Guinea resembles the syndrome reported from several tropical areas as Charmôt's disease or `le syndrôme splénomégalie–macroglobulinémie'. It probably represents an unusual immunological response to repeated infection with malarial parasites of varying antigenicity but there is no direct evidence for this proposal.