Lorestan University of Medical Sciences, Khorramabad, Iran.
Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
BMC Infect Dis. 2022 Jul 28;22(1):657. doi: 10.1186/s12879-022-07647-1.
Immunosuppressive chemotherapy increase the risk of vaccine-preventable infectious diseases in children; nevertheless, chemotherapy may result in delay or miss updated immunization schedules. The predictable antibody waning after incomplete primary immunization series may be intensified at the end of chemotherapy. This study aimed to investigate post-chemotherapy vaccine immunity waning at the end of immunosuppressive therapy in children with malignancy and hematologic disorders.
Children with malignancies and hematologic disorders including chronic immune thrombocytopenic purpura (ITP) younger than 18 years old were enrolled from September 2015 to August 2019. Eligible patients who completed their treatment protocol for at least 6 months were recruited. The patient information, including sex, age at the date of diagnosis, number of chemotherapy sessions, underlying disease, and vaccination history, was taken by chart review using predefined questionnaires. The patient's blood samples were obtained, and serum IgG antibody titer checked against diphtheria, tetanus, hepatitis B virus (HBV), mumps, measles, and rubella (MMR) were measured by enzyme-linked immunosorbent assay (ELISA).
110 children receiving immunosuppressive chemotherapy were recruited. Forty-four (40%) of the children tested were girls and 66 (60%) were boys. The mean age of patients was 5.5 years with a range of 2 to 13 years. Of 110 studied children, 27.3% were seronegative for all antibodies. On average, patients undergo 19 episodes of chemotherapy. The mean chemotherapy sessions were significantly greater in children who were seronegative for all tested antibodies (mean: 36.2, 95% CI 33.16 to 39.24, p-value < 0.001). No statistically significant differences were observed regarding the patient's sex and age between the seropositive and seronegative groups (p-value 0.513 and 0.060, respectively). Based on Poisson regression model analysis, the female gender was associated with 37% lower odds of seronegativity (incidence rate ratio (IIR): 0.63; [95% conf. interval: 0.39 to 1.01, p-value: 0.55]), while chemotherapy sessions 30 or more was associated with significant odds of seronegativity for all tested vaccines (IIR: 25.41; [95% conf. interval: 6.42 to 100.57, p-value < 0.001]).
Our results reemphasized planned catchup immunization in children undergoing immunosuppressive chemotherapy for malignancy, especially against tetanus, diphtheria, and hepatitis B at least 6 months after the end of chemotherapy sessions.
免疫抑制化疗会增加儿童患疫苗可预防传染病的风险；然而，化疗可能导致更新免疫接种计划的延迟或遗漏。在不完全的初级免疫接种系列之后，可以预测到的抗体衰减在化疗结束时可能会加剧。本研究旨在调查恶性肿瘤和血液系统疾病儿童在免疫抑制治疗结束时的疫苗后免疫衰减情况。
2015 年 9 月至 2019 年 8 月，招募了年龄小于 18 岁的恶性肿瘤和血液系统疾病的儿童，包括慢性免疫性血小板减少性紫癜（ITP）。招募了至少完成 6 个月治疗方案的合格患者。通过使用预定义问卷的图表回顾，获取患者的信息，包括性别、诊断时的年龄、化疗次数、基础疾病和疫苗接种史。使用酶联免疫吸附试验（ELISA）检测血清 IgG 抗体滴度，以检测白喉、破伤风、乙型肝炎病毒（HBV）、腮腺炎、麻疹和风疹（MMR）的抗体。
共招募了 110 名接受免疫抑制化疗的儿童。44 名（40%）儿童为女孩，66 名（60%）为男孩。患者的平均年龄为 5.5 岁，范围为 2 至 13 岁。110 名研究儿童中，27.3%的儿童对所有抗体均呈阴性。平均而言，血清学阴性的儿童接受的化疗次数明显更多（平均：36.2，95%CI 33.16 至 39.24，p 值<0.001）。在血清学阳性和阴性组之间，患者的性别和年龄没有观察到统计学上的显著差异（p 值分别为 0.513 和 0.060）。基于泊松回归模型分析，女性性别与血清学阴性的可能性降低 37%相关（发病率比（IIR）：0.63；[95%置信区间：0.39 至 1.01，p 值：0.55]），而化疗 30 次或更多与所有检测疫苗的血清学阴性的可能性显著相关（IIR：25.41；[95%置信区间：6.42 至 100.57，p 值<0.001]）。
我们的结果再次强调，对于接受恶性肿瘤免疫抑制化疗的儿童，特别是在化疗结束后至少 6 个月，应计划进行补种免疫，尤其是针对破伤风、白喉和乙型肝炎的疫苗接种。
