Hidalgo H, Moore C, Leiva L E, Sorensen R U
Department of Pediatrics, Louisiana State University Medical Center, New Orleans, USA.
Ann Allergy Asthma Immunol. 1996 Apr;76(4):341-6. doi: 10.1016/S1081-1206(10)60035-X.
Patients with recurrent infections and normal IgG levels may have an abnormal response to pneumococcal polysaccharides. The ability to develop antibodies against different pneumococcal polysaccharides develops gradually in the first years of life, but the sequence of development and the influence of preexisting antibody titers has not been defined.
Preimmunization and postimmunization IgG antibody titers against pneumococcal serotypes 3, 7F, 9N, and 14 were evaluated in a population of 100 1- to 18-year-old children referred to a pediatric allergy-immunology clinic because of recurrent respiratory infections. None of the patients had a known immunodeficiency syndrome; all had normal total IgG levels. Postimmunization antibody levels were obtained 4 to 6 weeks after immunization. Patients less than/=5 years of age who failed to develop antibody levels above 200 ng Ab N/mL against any serotype and older patients who failed to develop these levels against a second serotype in addition to serotype 3 were considered for IgG replacement therapy.
Prior to immunization, 50% of 51 patients did not have protective antibody levels against any of the serotypes tested. Immunization induced a high response to serotype 3 in all age groups, but responses to serotypes 7F and 14 increased with age. Five of 78 patients (6.4%) failed to develop protective antibody levels against any serotype tested. Three of these patients had clinical criteria that justified the use of IgG replacement therapy; all improved. Three patients were re-immunized 1 to 2 years after the first immunization and all developed protective levels of antibodies against serotype 3 after the second immunization.
We conclude that, although measurement of antibody levels against pneumococcal serotype 3 allows a good differentiation of patients who are able to develop anti-polysaccharide antibodies from those who are not, further studies of the development of specific antibodies against other vaccine serotypes in normal populations of different ages are needed to define a normal response to pneumococcal polysaccharides.
反复感染且免疫球蛋白G（IgG）水平正常的患者可能对肺炎球菌多糖有异常反应。针对不同肺炎球菌多糖产生抗体的能力在生命的最初几年逐渐发展，但发展顺序以及先前存在的抗体滴度的影响尚未明确。
对100名因反复呼吸道感染而转诊至儿科过敏免疫诊所的1至18岁儿童进行评估，检测其针对肺炎球菌血清型3、7F、9N和14的免疫前及免疫后IgG抗体滴度。所有患者均无已知免疫缺陷综合征；所有患者的总IgG水平均正常。免疫后4至6周获得免疫后抗体水平。5岁及以下未能针对任何血清型产生高于200 ng Ab N/mL抗体水平的患者，以及除血清型3外未能针对第二种血清型产生这些水平的年龄较大患者，被考虑进行IgG替代治疗。
免疫前，51名患者中有50%对所检测的任何血清型均无保护性抗体水平。免疫在所有年龄组中均诱导出对血清型3的高反应，但对血清型7F和14的反应随年龄增加。78名患者中有5名（6.4%）未能针对所检测的任何血清型产生保护性抗体水平。其中3名患者具有符合使用IgG替代治疗的临床标准；所有患者病情均有改善。3名患者在首次免疫后1至2年进行了再次免疫，所有患者在第二次免疫后均产生了针对血清型3的保护性抗体水平。
我们得出结论，尽管检测针对肺炎球菌血清型3的抗体水平能够很好地区分能够产生抗多糖抗体的患者和不能产生抗多糖抗体的患者，但需要对不同年龄正常人群中针对其他疫苗血清型的特异性抗体的发展进行进一步研究，以确定对肺炎球菌多糖的正常反应。
