Valentini Diletta, Marcellini Valentina, Bianchi Simona, Villani Alberto, Facchini Marzia, Donatelli Isabella, Castrucci Maria Rita, Marasco Emiliano, Farroni Chiara, Carsetti Rita
Pediatric and Infectious Disease Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Immunology Unit, Immunology and Pharmacotherapy Area, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Vaccine. 2015 Nov 27;33(48):6689-96. doi: 10.1016/j.vaccine.2015.10.083. Epub 2015 Oct 28.
Immunodeficiency is an integral aspect of Down syndrome, as demonstrated by the increased susceptibility to infection of affected. Mortality is still higher than in general population, with respiratory infections among the major causes of death. As more people with Down syndrome are living today than ever before, it is indispensable to develop strategies to prevent and cure the associated disorders. Vaccination is the most successful instrument of preventive medicine. Special seasonal influenza and pneumococcal vaccination strategies have been designed for individuals with risk conditions of all ages. Down syndrome individuals are not included in the high-risk categories.
We enrolled in our study 15 children with Down syndrome and their siblings, vaccinated for the first time with seasonal influenza vaccine and receiving a booster dose of a glyco-conjugated pneumococcal vaccine. We compared the immunological features and response to vaccination measuring serum antibody titers and frequency of specific memory B cells.
We confirm that a severe reduction of switched memory B cells is always associated to Down syndrome. After primary vaccination Down syndrome children generate significantly less specific switched memory B cells than their siblings. The response to a booster dose of vaccine is instead comparable in both groups. The production of specific antibodies was equally effective in Down syndrome and controls both after primary and secondary immunization.
Down syndrome individuals should be considered a high risk group, because of their increased susceptibility to infection and reduced number of switched memory B cells. Tailored vaccination protocols are needed in order to reduce their burden of infections throughout life.
免疫缺陷是唐氏综合征的一个重要方面，这表现为患者对感染的易感性增加。唐氏综合征患者的死亡率仍高于普通人群，呼吸道感染是主要死因之一。由于如今患有唐氏综合征的人数比以往任何时候都多，因此制定预防和治疗相关疾病的策略必不可少。疫苗接种是预防医学最成功的手段。针对所有年龄段有风险状况的个体设计了特殊的季节性流感和肺炎球菌疫苗接种策略。唐氏综合征患者并不在高危类别中。
我们招募了15名患有唐氏综合征的儿童及其兄弟姐妹，他们首次接种季节性流感疫苗，并接受一剂糖共轭肺炎球菌疫苗的加强剂量。我们通过测量血清抗体滴度和特异性记忆B细胞频率来比较免疫特征和疫苗接种反应。
我们证实，转换记忆B细胞的严重减少总是与唐氏综合征相关。初次接种疫苗后，唐氏综合征儿童产生的特异性转换记忆B细胞明显少于他们的兄弟姐妹。而两组对加强剂量疫苗的反应相当。初次和二次免疫后，唐氏综合征患者和对照组产生特异性抗体的效果相同。
唐氏综合征患者应被视为高危人群，因为他们对感染的易感性增加且转换记忆B细胞数量减少。需要制定量身定制的疫苗接种方案，以减轻他们一生的感染负担。
