Platelet aggregation by Herpes simplex antigen-antibody complexes

Differences in antibody responses in varicella, herpes zoster and after vaccination

Difference in antibody responses between varicella and herpes zoster was reconfirmed by complement fixation (CF) test and by platelet aggregation (PA) test. Rise in PA antibody level was observed only in patients with herpes zoster, but not in patients with varicella, while the increase in CF antibody was demonstrated in both types of the diseases. Among 235 healthy children, CF antibody was detected in 42 children and out of these 25 also had PA antibody. Sera of 116 individuals who were vaccinated with a live vaccine comprised of varicella-herpes zoster virus (VZV) were tested for CF and PA antibodies. Within six months after vaccination, 81.3 per cent of the vaccinees demonstrated the rise in CF antibody alone, and only one vaccinee possessed low level of PA antibody. Six months to 1 year after vaccination, CF antibody in 12 out of 13 vaccinees fell to undetectable level. Later than 1 year after vaccination, 9 out of 28 vaccinees possessed CF antibody. Two out of these 9 vaccinees also had PA antibody. The PA antigens prepared from viruses isolated either from a varicella patient or a herpes zoster patient responded similarly to the sera of herpes zoster patients, but no response was detected with sera of varicella patients. PA and CF antibody titers of herpes zoster patients showed a high degree of correlation.

Platelet immuno-assay (PIA) as a simple and sensitive technique for the detection of antigens

The platelet immuno-assay (PIA) is a simple and inexpensive technique to detect antigens with ng/ml sensitivity using micro-titer equipment and commercially available antisera. It can be easily adapted for virtually any antigen to which rabbit antiserum containing specific IgG-antibodies cna be obtained. The assay is inhibited by IgG and C1q in amounts greater than or equal to 125 microgram/ml and 12.5 microgram/ml respectively. Its application is thus limited to those fluids where IgG and C1q are present in less than these concentrations.