Relationship between preexisting anti-varicella-zoster virus (VZV) antibody and clinical VZV reactivation in hematopoietic stem cell transplantation recipients

Abstract

Reactivation of latent varicella-zoster virus (VZV), presenting as localized zoster or as disseminated infection, is a common and potentially serious complication in hematopoietic stem cell transplantation (HSCT) recipients. We retrospectively studied anti-VZV immunoglobulin G titers by the immune adherence hemagglutination method after HSCT and also studied VZV DNA by real-time PCR during clinical VZV reactivation using cryopreserved serum samples. No significant difference was found between anti-VZV titers in 13 patients with VZV infection (localized zoster in 11 patients and disseminated zoster in 2 patients) and in 13 subjects without VZV infection at each time point after HSCT. Preexisting anti-VZV titers of disseminated zoster cases tended to be lower than those of localized zoster cases (P=0.10). Serum VZV DNA copy numbers at the onset of disseminated zoster cases tended to be higher than those of localized zoster cases (P=0.09). A strong inverse correlation was found between preexisting anti-VZV titer and serum VZV DNA at onset (r=-0.90, P=0.006). In HSCT recipients, preexisting antibody does not prevent the development of VZV reactivation but may contribute to decreased viral load at onset, resulting in a mild clinical course.

FIG. 1.

(A) Transition of anti-VZV titer after HSCT (control, ▴; localized zoster, •; disseminated zoster, ○). In cases of VZV infection, only the results before VZV onset were plotted. (B) Transition of anti-VZV before, at onset of and after VZV infection in 13 cases of VZV reactivation (localized zoster, •; disseminated zoster, ○). VZV infection within the first 6 months after HSCT (continuous line) and VZV infection at more than 6 months after HSCT (dashed line) are also indicated. (C) Correlation of preexisting anti-VZV titer and serum VZV DNA (localized zoster, •; disseminated zoster, ○). Preexisting anti-VZV titer and serum VZV DNA were inversely correlated (determined by Pearson correlation test; r = −0.90, P = 0.006).