Antibodies to Epstein-Barr virus-specific antigens in patients with hairy-cell leukemia.

Antibody titers to Epstein-Barr virus (EBV)-specific antigens of 19 patients with hairy-cell leukemia (HCL) were markedly elevated. All patients showed high titers of IgG anti-viral capsid antigen (VCA) reactivity equal to or greater than 320 (reciprocal titer). The anti-VCA reciprocal geometric mean titer (GTM) was 1106 in contrast to a GMT of 80 for healthy controls (p less than 0.001). No IgM anti-VCA antibody was detected, but three patients had IgA anti-VCA antibodies. Fourteen patients had elevated anti-early antigen (EA) titers (GMT = 177) which were indicative of active infections with EBV. Seven of the 14 patients demonstrated the diffuse component antibody of the early antigen (EA) complex at a GMT of 98. Anti-Epstein-Barr virus nuclear antigen (EBNA) was detected in sera of 16 patients (GMT = 64, controls GMT = 79). It is noteworthy that three patients with anti-VCA titers lacked anti-EBNA titers. These anti-body responses suggest that immunodeficiency secondary to HCL allowed reactivation of the virus.