Molecular characterization of hepatitis B virus (HBV) isolated from a pediatric case of acute lymphoid leukemia, with a delayed response to antiviral treatment: a case report.

Autor: Chen CY; Hepatitis Virus Diversity Research Unit, Department of Internal Medicine, University of the Witwatersrand, Johannesburg, South Africa., Hajinicolaou C; Department of Paediatrics, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.; Paediatric Gastroenterology, Hepatology and Nutrition Unit, Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa.; Paediatric Gastroentrology, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa., Walabh P; Paediatric Gastroenterology, Hepatology and Nutrition Unit, Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa., Ingasia LAO; Hepatitis Virus Diversity Research Unit, Department of Internal Medicine, University of the Witwatersrand, Johannesburg, South Africa., Song E; Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa., Kramvis A; Hepatitis Virus Diversity Research Unit, Department of Internal Medicine, University of the Witwatersrand, Johannesburg, South Africa. Anna.Kramvis@wits.ac.za.
Jazyk: angličtina
Zdroj: BMC pediatrics [BMC Pediatr] 2022 Mar 31; Vol. 22 (1), pp. 168. Date of Electronic Publication: 2022 Mar 31.
DOI: 10.1186/s12887-022-03204-6
Abstrakt: Background: Tenofovir disoproxil fumarate (TDF) is effectively used as the first-line antiviral for chronic hepatitis B virus (HBV) infection in adults and children older than 12 years. To date, no confirmed case of virologic breakthrough (VBT) in a pediatric case has been reported.
Case Presentation: Here we describe a case of a 5-year old, asymptomatically infected with HBV infection two months after chemotherapy for precursor B acute lymphoblastic leukemia (ALL). Although the 5-year old male is South African, his family originated from Guinea. At the end of the one-year follow-up, the infection progressed to chronic HBV infection, with a high viral load. At 36 weeks (8 months) post-treatment with lamivudine (LAM), there was a partial virologic response (PVR) and after 61 weeks (14 months), he was switched to TDF rescue monotherapy. Even with TDF treatment, he still experienced VBT and subsequent PVR. The full-length genome of HBV isolated 78 weeks after the switch to rescue TDF monotherapy was sequenced and belonged to genotype E. In addition to the LAM mutations (rtS256G and rtM267L), missense mutations in B-cell, T-cell, HLA class I and II-restricted epitopes emerged, which were to evade and escape host surveillance, leading to delayed viral clearance, persistence and disease progression. Two further events of VBT occurred between weeks 113 and 141 of TDF rescue-therapy. Viral loads and liver enzymes are normalizing progressively with long-term therapy.
Conclusion: Although the host immune reconstitution may be delayed, prolonged TDF treatment was effective in treating this pediatric case of HBV infection with VBT and PVR.
(© 2022. The Author(s).)
Databáze: MEDLINE
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