The demonstration of cell-associated immunity to viruses. In vitro lymphocyte responsiveness to Varicella-zoster antigen

Varicella-zoster-specific immune responses in acute herpes zoster during a placebo-controlled trial of oral acyclovir therapy

During a placebo-controlled trial of oral acyclovir therapy for acute zoster in immunocompetent patients, we examined the blastogenic response of peripheral blood mononuclear cells and antibody titers in both placebo and acyclovir recipients to determine whether the drug affected the cell-mediated or humoral immune responses. Proliferative responses to mitogens and two dilutions of varicella-zoster virus antigen were not inhibited when fresh peripheral blood mononuclear cells were simultaneously tested in autologous sera collected before and on day 7 of a 10-day course of 2 g/day of oral acyclovir (plasma drug levels averaged 4.6 microM). Using cryopreserved cells from study days 0, 3, 7, 14, and 30, thawed and tested simultaneously, there was no significant difference at the p less than or equal to 0.05 level between the net proliferative responses at each time point for the two groups. On day 14, however, the proliferative response of the acyclovir group was approximately 50% lower than that of the placebo group. Geometric mean antibody titer rises to varicella-zoster virus were also lower among drug recipients but not significantly so. Although this dose of acyclovir did not have a statistically significant effect on lymphocyte proliferative responses to varicella-zoster virus antigen or antibody titers, the lower values in drug recipients may be a reflection of the ability of acyclovir to terminate viral replication, thus reducing the patient's antigenic burden.

Immunity to cytopathic agents associated with Crohn's disease: a negative study

Serum and peripheral blood lymphocytes from 10 patients with Crohn's disease and 10 healthy subjects were examined for immunological reactivity against chick embryo cell cultures displaying cytopathic effects after inoculation with 0.2 micro filtrates prepared from Crohn's disease intestinal tissues. Although the assay systems (indirect immunofluorescence, lymphocyte transformation, and cytotoxicity) yielded positive results using well-characterized cytopathic viruses (mumps, measles), neither Crohn's disease nor healthy subjects showed immune reactivity to the chick embryo cell cultures inoculated with Crohn's disease intestinal tissues in any of the assay systems. These experiments provide evidence against the hypothesis that the in vitro cytopathic effect on chick embryo cell cultures produced by Crohn's disease intestinal filtrates are caused by a replicating virus or viruses.

Decrease of the lymphoproliferative response to varicella-zoster virus antigen in the aged

Humoral antibodies and specific cellular immune reactions (proliferative immune response in the lymphocyte transformation test) to varicella-zoster virus antigen were measured in children, young adults, and elderly people. In children and young adults, the humoral varicella-zoster-specific antibodies and the virus-specific cellular immune response generally coincided. In the over-60 age group, however, a discrepancy was often observed between these parameters. Ninety percent of the elderly subjects showed humoral antibodies, but only 64% still had a measurable varicella-zoster-specific immune response. There was no correlation between the magnitude of the virus antigen-specific immune response and the mitogen-induced lymphoproliferative response (phytohemagglutinin stimulation). One in three elderly people, therefore, showed no cellular immune response to the varicella-zoster virus antigen, and this person could probably be regarded as a potential herpes zoster patient.

Herpes zoster and impaired cell-associated immunity to the varicella-zoster virus in patients with Hodgkin's disease

Thirty-two patients with Hodgkin's disease and 12 normal donors were studied for their in vitro lymphocyte responsiveness to a membrane-associated varicella-zoster (VZ) antigen. When compared to the normal donors, patients with Hodgkin's disease in whom radiotherapy was recently completed and those with active, recurrent disease had markedly impaired cell-associated immunity to VZ antigen. In addition, there was a suggestion that patients in long-term remission who had received primary combined modality therapy (radiotherapy plus chemotherapy) had an impaired response when compared to normal persons or to patients who had received single modality therapy. Newly diagnosed, untreated patients with Hodgkin's disease did not differ significantly from normal persons as a group but two of six were unresponsive to the VZ antigen whereas all normal subjects were responsive. Most patients in remission for at least one year following therapy had normal in vitro responsiveness. In two patients herpes zoster developed after the demonstration of absent in vitro lymphocyte reactivity to the VZ antigen.