A prospective multicenter study on varicella-zoster virus infection in children with acute lymphoblastic leukemia

Lymphocyte counts predict optimal timing of chemotherapy reinitiation after antivirus treatment for herpes zoster in children with leukemia

Herpes zoster (HZ) is rare in healthy children, but more prevalent in those with leukemia. Optimal timing of chemotherapy reinitiation after HZ treatment is challenging because chemotherapy suppresses immunity and increases risk of HZ relapse. We aimed to optimize the timing of chemotherapy reinitiation after HZ therapy in children with leukemia. The study included 31 children with acute leukemia and HZ infection. General information, clinical symptoms, laboratory test results, duration of HZ treatment, and prognosis were compared with those of children with leukemia alone. Correlation analysis was performed for 20 children who restarted chemotherapy after HZ treatment. Of 31 children with leukemia and HZ, 67.74% had lesions at multiple sites. The median time from chemotherapy initiation to HZ onset was 14.1 (1.5-29.5) months. Among 27 children included in the follow-up, there was one case of HZ relapse. After excluding children who did not continue chemotherapy after HZ treatment, the median interval between completion of HZ therapy and chemotherapy reinitiation in the remaining 20 children was 8.00 (- 3 to 27) days. Lymphocyte counts (LY#) on restarting chemotherapy correlated inversely with HZ lesion healing time (p < 0.05). LY# at the time of HZ onset were lower than those pre- and post-onset, and lower than those in the control group (p < 0.05). In conclusion, children with leukemia have a good HZ prognosis, but an increased risk of HZ recurrence. LY# at the time of chemotherapy reinitiation may be a useful indicator for selecting the optimal interval between antiviral therapy completion and chemotherapy reinitiation.

Could Herpesviridae be the cause of severe acute hepatitis of unknown origin in children?

INTRODUCTION

Severe acute hepatitis (SAH) is defined by a severe inflammation of hepatocytes in the liver parenchyma which can lead to an acute liver failure, a clinical condition with high mortality rate that can be triggered by several factors but is usually associated to hepatotropic viruses' infection. In 2022, cases of children with severe acute hepatitis of unknown origin hospitalized in Glasgow, Scotland, were reported. Possible causes of this condition include, but are not limited to, undiagnosed viral (and non-viral) infections, autoimmune hepatitis, drug and/or chemical toxicity, mitochondrial chain respiratory and metabolic disorders.

AREAS COVERED

Herpesviruses can cause severe acute hepatitis, but little is known about the role and the mechanisms of herpesviruses as a causative agent of this type of hepatitis. We review the role of herpesviruses as causative agent of SAH in children and other possible mechanisms involved in this disease.

EXPERT OPINION

Differential diagnosis for herpesvirus in SAH should be implemented in all settings. Alternative fluids, such as saliva and dried blood, could be used in the diagnosis to overwhelm the availability of biological specimens at sufficient volume. In the future, genetic studies could also be added to increase the knowledge about severe acute hepatitis in children.