To the Editor
With great interest, we read an Article published at The Lancet Regional Health - Americas by Pablo F. Belaunzarán-Zamudio and colleagues.1 The authors estimated the seroprevalence of hepatitis C virus (HCV) among adults with HIV in Mexico. Despite the strengths of this study, a technical issue should be considered.
The key to this study was the stability of anti-HCV IgG antibodies in blood samples, which were detected by a qualitative enzyme-linked fluorescent assay (VIDAS™ anti-HCV, BioMerieux). According to the authors, “Blood samples were shipped to the Serology and the Molecular Virology Laboratories of the Department of Infectious Diseases at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City, where samples were centrifuged, and serum stored in 1 mL vials at −70 °C until processed”, blood samples were transported to Mexico City from all over the country. Storage conditions and transportation time of blood samples were not described in the methods of the study. The performance of antibody-based assays relies on skilled blood collection followed by standardised methods of sample handling, serum separation and storage.2 The mishandling treatments, repetitive freezing and thawing, haemolysis and heat, might occur during routine blood collection, transport or storage. Although anti-HCV IgG antibodies in serum samples are regarded to be relatively stable under basic cold-chain storage conditions, there is no evidence available on the stability of anti-HCV IgG antibodies in blood samples.3,4 The stability of anti-HCV IgG antibodies in blood samples could influence the study conclusion.
Notably, the relationship between storage conditions and anti-HCV IgG antibodies in blood samples should be further investigated. The sample collection, processing, storage conditions, and transport conditions should be introduced in “Materials and Methods” during serological studies of HCV in the future. If the seropositive samples from this study were still stored, the stability of anti-HCV IgG antibodies in serum samples stored in differing conditions and multiple freeze-thaw cycles should be evaluated.5
Contributors
Lihua Yang, Yongzhi Wang, Yibo Zhao, Fangyu Zhang, Li Guo, Xiaogang Yan, and Jinghui Zhao contributed equally to this article.
Declaration of interests
We declare no competing interests.
Acknowledgements
This work was supported in part by grants from Changchun Science and Technology Development Plan Project of China (2024CNZ05) and the Central Government Guides Local Science and Technology Development Funds (the second batch) to Support Projects of China (YDZJ202203CGZH050).
References
- 1.Belaunzarán-Zamudio P.F., Mosqueda-Gómez J.L., Cano-Torres J.O., et al. Prevalence of hepatitis C virus co-infection in adults living with HIV in Mexico: a cross-sectional, seroprevalence study in a nationally representative sample. Lancet Reg Health Am. 2024;41 doi: 10.1016/j.lana.2024.100965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Kurian A., Neumann E.J., Hall W.F., et al. Effects of blood sample mishandling on ELISA results for infectious bronchitis virus, avian encephalomyelitis virus and chicken anaemia virus. Vet J. 2012;192(3):378–381. doi: 10.1016/j.tvjl.2011.08.028. [DOI] [PubMed] [Google Scholar]
- 3.Øverbø J., Aziz A., Zaman K., et al. Stability and feasibility of dried blood spots for hepatitis E virus serology in a rural setting. Viruses. 2022;14(11):2525. doi: 10.3390/v14112525. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Hacıseyitoğlu D., Yılmaz Ş., Erdoğan F., et al. Stability of SARS-CoV-2 antibody in serum under various usage and storage conditions. J Infect Dev Ctries. 2024;18(9.1):S101–S106. doi: 10.3855/jidc.18919. [DOI] [PubMed] [Google Scholar]
- 5.Shurrab F.M., Al-Sadeq D.W., Amanullah F., et al. Effect of multiple freeze-thaw cycles on the detection of anti-SARS-CoV-2 IgG antibodies. J Med Microbiol. 2021;70(8) doi: 10.1099/jmm.0.001402. [DOI] [PMC free article] [PubMed] [Google Scholar]