IMMUNOPHENOTYPING IN PRESUMED OCULAR HISTOPLASMOSIS LIKE RETINOPATHY

Four cases of presumed ocular histoplasmosis like retinopathy are pres ented. A detailed immunological assessment was carried out on the pati ents and a control group: lymphocyte immunophenotyping; flow cytometri c analysis; HLA typing and T cell receptor variable region (TCR V regi on) expression were assessed, Analysis of TCR V region expression reve aled no significant preferential expression, HLA typing also failed to reveal any links. All lgmphocyte markers analysed were unremarkable, with the exception of CD38 which was significantly raised compared wit h controls (p<0.01). This finding was confirmed by the use of two diff erent CD38-specific monoclonal antibodies. The raised CD38 in our case s was shown to be persistent when the patients were retested after an interval of several months, Significantly, this may correlate with poo r T cell function, as in Common Variable Immunodeficiency, making thes e patients more susceptible to various stimuli.