Mitogenic activity of an extract of Trypanosoma gambiense.

An extract obtained by repeated freeze/thawing of a freshly isolated strain of Trypanosoma gambiense caused stimulation of lymphocytes obtained from healthy adult donors and from cord blood. The active factor had some stimulatory effect on purified B and T lymphocytes and in two of five subjects increased IgM production by lymphocytes cultured in vitro. A trypanosome-derived mitogenic factor may play some part in the pathogenesis of the hypergammaglobulinaemia characteristic of African trypanosomiasis.