Clinical study on varicella zoster virus infection in children following allogeneic hematopoietic stem cell transplantation

Objective To analyze the risk factors of varicella zoster virus(VZV) infection after allogeneic hematopoietic stem cell transplantation(allo-HSCT) in children, and to provide reference for the diagnosis, monitoring and prophylaxis of VZV infection after allo-HSCT. Methods A total of 367 patients, who underwent allo-HSCT in Pediatric Transplantation Center of Nanfang Hospital Affiliated to Southern Medical University from January 2012 to June 2015 were collected.Clinical characteristics and risk factors of the patients complicated with VZV after allo-HSCT were retrospectively analyzed. Results Thirty-four patients (9.26%) were complicated with VZV infection after allo-HSCT.The median onset time was 96.5 d(19-326 d). Two of 34 patients relapsed 3 times, 1 case of them relapsed twice, 3 cases of them relapsed once, and 4 cases of 34 patients were complicated with VZV encephalitis.All cases were treated with antivirus drugs, infusion of immunoglobulin, reduction of immunosuppressant dosages, with external use of Acyclovir ointment.The median therapy time was 13 days (7-28 days). All of their herpes subsided, and neurological symptoms such as headache, vomiting and convulsion disappeared.VZV-DNA both in blood and cerebrospinal fluid turned negative.No patient had herpetic dissemination and visceral involvement, and no one died directly of VZV infection.Results indicated that age(χ2=6.863, P=0.009), underlying disease(χ2=14.793, P=0.022), type of HSCT(χ2=14.459, P=0.001) and resource of stem cell (χ2=20.585, P=0.002) were significant risk factors for VZV infection after allo-HSCT, while sex (χ2=0.106, P=0.745) and antithymocyte globulin in conditioning regimen(χ2=0.010, P=0.921) had no relation to it. Conclusions VZV infection mainly occur within 12 months after allo-HSCT and is prone to be complicated with VZV encephalitis.The effect of Acyclovir is good.Monitoring and prophylaxis of VZV infection after allo-HSCT should be strengthened in children with high risk factors. Key words: Varicella zoster virus; Allogeneic Hematopoietic stem cell transplantation; Child; Prophylaxis