Lymphocyte phenotype changes in congenital and acquired perinatal cytomegalovirus infections.

The recognition that the multiple functions of T-lymphocytes are accomplished by separate subpopulations of cells that can be delineated both functionally and by antisera directed against specific cell surface markers is one major advance in immunology. Our study was directed at enumerating lymphocyte subsets in cytomegalovirus (CMV) perinatal infections with monoclonal antibodies and cell flow cytometry. Eight patients ranging in age from 1 week to 2 1/2 months were studied. Except for one term neonate, all of the infants were less than 36 weeks of gestational age, with a mean of 31.5 weeks (range 27-36 weeks) at birth. The mean birth weight of the premature infants was 1,211 gm (range 870-2420 gm). Five patients were 3 weeks old when studied and were classified as congenital CMV by viral isolation. Three were older than 2 months and were classified as acquired CMV. One of the acquired CMV infants was followed from birth to 6 months of age and had normal lymphocyte numbers at 2 weeks with alterations appearing at 8 weeks. The results of these studies indicated that in congenital CMV there is a normal to high helper/suppressor ratio. On the contrary, in acquired CMV this ratio is profoundly depressed because of significant increase in suppressor T-lymphocytes with borderline normal helper T-lymphocytes. In the latter group, the ratio increased with time after the acute infection episode. Our results agree with reported data indicating that in adults with CMV there is a depression of the helper/suppressor ratio during the acute stage with a return toward normal values during convalescence.