Reduced cellular immunity to varicella zoster virus during treatment for acute lymphoblastic leukemia of childhood: in vitro studies of possible mechanisms

Varicella-zoster virus: aspects of pathogenesis and host response to natural infection and varicella vaccine

Events in the pathogenesis of infection and the host response to VZV are very closely linked. Our experiments demonstrate that CD4- and CD8+ T-lymphocyte populations that are targets of cell-associated VZV viremia also mediate protection against severe infection. Diminished cell-mediated immunity predisposes the host to progressive primary or recurrent VZV disease because infected lymphocytes persist in the circulation and carry the virus to major organs, causing pneumonitis, hepatitis, or other life-threatening complications. The live attenuated varicella vaccine induces cell-mediated immunity and protects against or significantly reduces the morbidity associated with primary VZV infections. The universal administration of varicella vaccine is likely to generate new insights about host-virus interactions, particularly in relation to how VZV immunity is maintained, that will be relevant to the design of vaccines for other human herpesviruses.

Impaired expression of interleukin 2 receptor and CD45RO antigen on lymphocytes from children with acute lymphoblastic leukemia in response to cytomegalovirus and varicella-zoster virus

The expression of CD25 and CD45RO in lymphocytes from patients with acute lymphoblastic leukemia in response to cytomegalovirus and varicella-zoster virus antigens was analyzed by flow cytometry. It is suggested that the defects in the immune response to cytomegalovirus and varicella-zoster virus in patients with acute lymphoblastic leukemia on chemotherapy are in the expression of CD25 and in the switching of CD45RA cells to CD45RO cells.

T-lymphocyte subsets in otherwise healthy patients with herpes zoster and relationships to the duration of acute herpetic pain

T-lymphocyte subsets (CD3, CD4, and CD8 lymphocytes) in peripheral blood, parameters of cell-mediated immunity, were serially measured in 62 otherwise healthy Japanese patients with herpes zoster (HZ), and the findings were compared with those of 20 age-matched healthy controls who had had varicella but not HZ. Our objective was to elucidate whether there were changes in cell-mediated immunity, even in immunocompetent patients with HZ, and to investigate relationships between these variables and the duration of acute herpetic pain (AHP). All the patients underwent repeated sympathetic nerve blocks until pain was relieved. As compared with controls, there were slight increases in the percentages of CD4 lymphocytes (helper/inducer) and highly significant increases in the percentages of CD8 lymphocytes (suppressor/cytotoxic), resulting in marked decreases in CD4/CD8 ratios in the acute phase of HZ. The percentages of CD3 lymphocytes (pan-T lymphocytes) did not differ significantly. The duration of AHP was analyzed in 49 patients in whom T-lymphocyte subsets were measured more than twice. There was a weak but statistically significant positive linear correlation between age and the duration of AHP (r = 0.43, P < 0.01). There were statistically highly significant positive linear correlations between the number of days on which percentages of CD3 (r = 0.72, P < 10(-8)) and CD4 lymphocytes (r = 0.60, P < 10(-5)), and CD4/CD8 ratios (r = 0.62, P < 10(-5)) reached the maximum values after the onset of HZ and the duration of AHP. These correlation coefficients were higher than that between age and the duration of AHP.(ABSTRACT TRUNCATED AT 250 WORDS)

Varicella vaccine in children with acute lymphoblastic leukemia and non-Hodgkin lymphoma

To determine the safety and efficacy of varicella vaccine, 17 children with acute lymphoblastic leukemia (ALL) and 2 children with non-Hodgkin lymphoma (NHL) receiving chemotherapy in remission were immunized with live attenuated varicella vaccine (Oka strain). Rash occurred in 7 children 7-53 days (median 24 days) after vaccination. There were 10-80 (median 20) erythematous vesicles and low-grade fever. All children required no specific treatment. There was no spread of varicella to their susceptible siblings. The control group comprised 92 ALL and 25 NHL patients receiving chemotherapy in remission who were nonvaccinated and susceptible to varicella. Over a risk duration of 80 person-years, one child of the vaccinated group developed varicella of mild degree, whereas in a risk duration of 120 person-years, 14 of the control group developed varicella. One patient died, though prompt antiviral therapy, especially acyclovir, was given to all of them. Herpes zoster of mild degree was observed in one child of the vaccinated group 65 days after vaccination. Two children of the control group developed disseminated herpes zoster. With acyclovir therapy, there was no mortality. The incidence of varicella in the vaccinated group was less than that of the control group. The difference is statistically significant (p = .0222), and the side effects of the vaccine were acceptable. Thus we conclude that the vaccine can be safely used in children with ALL or NHL under chemotherapy and can effectively protect such children from varicella.

External ocular herpesvirus infections in immunodeficiency

Infections of the eye with members of the herpes family of viruses (e.g. HSV, CMV, VZV) are frequent manifestations of acquired and inherited defects in cell mediated immunity. Herpesvirus infections in the immunocompromised may reflect frequent viral reactivation from the latent state, as well as extensive productive infection of ocular structures following reactivation or primary infection. A review of experimental and clinical studies of both acquired and inherited immune dysfunction implicates specific immune mechanisms influencing the establishment of latency, viral reactivation and the control of active viral replication in ocular tissues.