Abstract
The asymptomatic hemizygous female carriers of the X-linked lymphoproliferative syndrome (XLP) have abnormal antibody responses to EBV. This suggests partial expression of the defect that leads to EBV-provoked life-threatening diseases in their affected sons. EBV specific antibodies were measured in serum samples of obligate carrier females and their daughters (females at risk) during periods ranging from 1 to 5 yr. Abnormal qualitative antiviral capsid antigen (VCA) IgG titers were nearly fourfold higher than normal controls, two carriers had persistent IgM anti-VCA antibody, two thirds had persistent IgA anti-VCA antibody, and half of the women had titers to early antigen (EA). Five of seven females exhibited a similar persistent pattern. These findings may prove useful for detecting carriers of the syndrome. Abnormal anti-EBV titers similar to he carrier pattern have been reported in patients and other immunosuppressed individuals, and are indicative of active viral infection.