Early diagnosis and monitoring of adaptive immune response in a cohort of mild mpox patients during the 2022 wave

Our study wants to describe the kinetics of serological and adaptive immune responses in mpox patients. Methods. Fourteen patients with a laboratory-confirmed mpox were tested at different time points after symptoms onset. An immunofluorescence assay was performed to evaluate seroconversion kinetics of specific IgA, IgM, and IgG. Moreover, the characterization of the adaptive immunological profile of T- and B-cells was performed. Results. Antibody kinetics revealed faster and more effective seroconversion of specific IgA than IgM. Moreover, we detected an increase of Active B memory cells and CD8+ cells in the early phases of infection, and a reduction of CD4+ T- in mpox patients with respect to controls; with a different CD8 active T-cells profile in HIV+ compared to HIV- subjects. Moreover, we found the presence of higher levels of Treg cells in HIV+ patients in the early phase of infection. Conclusion: Our data highlighted the relevance of specific IgA testing early after SO, suggesting a possible role as a marker in early diagnosis, especially in close contact subjects. Furthermore, after symptoms’ onset we observed a different maturation state of effector cells in HIV+ patients that, together with high Treg levels, may lead us to better understand the role of MPXV-HIV co-infection in disease progression.

本研究旨在描述猴痘（mpox）患者血清学与适应性免疫应答的动力学特征。
方法：本研究纳入14例经实验室确诊的猴痘患者，于症状发作后不同时间点开展检测。采用免疫荧光试验（immunofluorescence assay）检测特异性IgA、IgM及IgG的血清转换动力学；同时对T细胞与B细胞的适应性免疫谱进行表征分析。
结果：抗体动力学分析显示，特异性IgA的血清转换速度与效率均优于IgM。研究团队在感染早期检测到活化B记忆细胞与CD8+T细胞数量升高，猴痘患者的CD4+T细胞数量相较于对照组有所降低；HIV阳性（HIV+）受试者与HIV阴性（HIV-）受试者的CD8活化T细胞谱存在显著差异。此外，感染早期HIV阳性患者体内的调节性T细胞（Treg）水平更高。
结论：本研究结果凸显了症状发作早期检测特异性IgA的临床价值，提示其可作为早期诊断的生物标志物，尤其适用于密切接触人群。此外，症状发作后，HIV阳性患者的效应细胞成熟状态存在异常，结合其高水平的调节性T细胞，有助于进一步理解猴痘病毒（MPXV）与HIV合并感染对疾病进展的影响。