Anticomplement immunofluorescence for the titration of antibody to varicella-zoster virus

Anticomplement immunofluorescence (ACIF) was tested for its use for the titration of antibody against varicella-zoster virus (VZV). ACIF antibody responses of patients with VZV infection were specific for VZV antigen and heterotypic responses to herpes simplex virus type-1 and cytomegalovirus antigens were not observed. Comparative studies of ACIF, membrane immunofluorescence (MIF) and indirect immunofluorescence (IF), using acetone-fixed antigen, were carried out with nonimmune sera and convalescent sera of patients who had recovered from varicella, herpes zoster and Rumsey Hunt disease. Nonspecific staining occurred with some nonimmune sera at a 1:4 dilution in the MIF and IF tests, after freezing and thawing of the serum, but not in the ACIF test. The antibody titers in convalescent sera agreed well in these three methods and the highest titer was obtained by MIF. The titers in ACIF and IF were similar but the ACIF antibody decreased earlier than the IF antibody during convalescence. On the other hand there was a discrepancy between the titers of ACIF and those of MIF and IF antibody in the sera of healthy adults, all sera with titers higher than 10 in the MIF and IF tests had titers below 10 in the ACIF test. The average titer of ACIF antibody declined to less than 10 with increasing age (13 to more than 20 years), whereas the MIF antibody increased during the same period of life.