Varicella-zoster antibody titers in children with leukemia and lymphoma. Relationship of titer to varicella-zoster infection.

Serum varicella-zoster (VZ) antibody titers were determined by a simple, indirect immunofluorescent antibody technique in 50 children with leukemia or non-Hodgkin's lymphoma. Sixteen children had initial antibody titers that were not detectable at a serum dilution of 1:8 and were considered to be susceptible to varicella. Thirty-one patients had initial serum VZ antibody titers of 1:16 or greater, while three had levels of 1:8. The serum antibody titer was 1:8 or greater in 16 children with a history of varicella. Seven episodes of localized herpes zoster were observed in children whose VZ titer was 1:8 or greater prior to onset. Two nonfatal infections with primary varicella developed in children with leukemia in remission whose initial titers were less than 1:8 and were associated with a convalescent rise in VZ antibody to levels greater than 1:16. Three susceptible children received zoster immune plasma or zoster immune globulin for varicella exposure, causing a transient rise in serum VZ titer. The assessment of serum VZ titer by this immunofluorescent antibody technique combined with the prior varicella history is useful in defining the population of children with leukemia and non-Hodgkin's lymphoma who are susceptible to primary varicella.