Choi Daniel K, Fuleihan Ramsay L, Walterhouse David O
Division of Pediatric Hematology/Oncology, Department of Pediatrics, University of Illinois at Chicago College of Medicine, Chicago, Illinois.
Division of Allergy/Immunology, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago/Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Pediatr Blood Cancer. 2016 Nov;63(11):2011-8. doi: 10.1002/pbc.26110. Epub 2016 Jun 21.
Influenza is a health risk to children receiving chemotherapy for cancer. An absolute lymphocyte count (ALC) >1,000 cells/mm(3) has been associated with the ability to produce an immune response to influenza vaccine during chemotherapy. However, clinical efficacy of influenza vaccination during chemotherapy remains unclear.
We conducted a prospective cohort study in children receiving chemotherapy for cancer during two consecutive influenza seasons. Assessments of immune cells and serologic response were measured immediately before and after receiving influenza vaccine. Patients were monitored for influenza or influenza-like illness (ILI).
Two hundred fifty-nine patients were studied over 2 years. The seroresponse rate was 62% (98/157). The median ALC at vaccination was higher in seroresponders than nonresponders, 854 cells/mm(3) versus 602 cells/mm(3) , respectively (P < 0.036). Univariate analysis showed that patients with an ALC <1,000 cells/mm(3) at the time of vaccination were twice as likely to be sero-nonresponders (P < 0.02, OR = 2.4, 95% CI: 1.1-5.0). Twelve percent (31/259) of patients developed influenza, of whom all had fever at presentation, 26% (8/31) required hospitalization, and 81% (25/31) had chemotherapy delays. No deaths were associated with influenza infection. The proportion of patients with influenza was not different between seroresponders and nonresponders.
Influenza infection following immunization remains a source of morbidity in children undergoing chemotherapy. Lymphopenia at vaccination predicted sero-nonresponse. Seroresponse was not associated with a decreased frequency of influenza infection or ILI when compared to sero-nonresponders, suggesting clinical effectiveness of vaccination is likely multifactorial. Further investigation into the efficacy of the influenza vaccine is needed to refine immunization recommendations.
流感对接受癌症化疗的儿童构成健康风险。绝对淋巴细胞计数（ALC）>1000个细胞/mm³与化疗期间对流感疫苗产生免疫反应的能力相关。然而，化疗期间流感疫苗接种的临床疗效仍不明确。
我们在连续两个流感季节对接受癌症化疗的儿童进行了一项前瞻性队列研究。在接种流感疫苗前后立即测量免疫细胞和血清学反应。对患者进行流感或流感样疾病（ILI）监测。
在2年期间对259名患者进行了研究。血清反应率为62%（98/157）。血清反应者接种疫苗时的ALC中位数高于无反应者，分别为854个细胞/mm³和602个细胞/mm³（P<0.036）。单因素分析显示，接种疫苗时ALC<1000个细胞/mm³的患者血清无反应的可能性是前者的两倍（P<0.02，OR=2.4，95%CI：1.1-5.0）。12%（31/259）的患者患流感，所有患者就诊时均有发热，26%（8/31）需要住院治疗，81%（25/31）化疗延迟。没有死亡与流感感染相关。血清反应者和无反应者之间患流感的患者比例没有差异。
免疫后流感感染仍然是接受化疗儿童发病的一个原因。接种疫苗时淋巴细胞减少预示血清无反应。与血清无反应者相比，血清反应与流感感染或ILI频率降低无关，这表明疫苗接种的临床有效性可能是多因素的。需要进一步研究流感疫苗的疗效以完善免疫接种建议。
