Distribution pattern of peripheral lymphocyte subsets in localized and generalized form of onchocerciasis

The relationship of peripheral lymphocyte subpopulations to the generalized and localized form of onchocerciasis has been studied in 43 Liberian (West African) patients. Typing revealed a significantly increased proportion of lymphocytes expressing interleukin 2 or transferrin receptors in the localized form of onchocerciasis (African sowda) when compared to subjects with a generalized form and those without signs of onchocerciasis. Patients with African sowda showed a higher number of helper/inducer T cells, a greater ratio of helper/inducer: suppressor/cytotoxic T cells, and an increased number of DR antigen-positive cells and lymphocytes with a natural killer cell phenotype. Furthermore, the serum concentrations of immunoglobulins, particularly IgE an IgG, and antifilarial antibodies were significantly elevated in sowda patients in comparison to the generalized form and the controls. These results indicate that both forms of onchocerciasis represent different immunological types of host responsiveness and that African sowda might be associated with an increased compartment of activated T lymphocytes.