Gross S, Blaiss M S, Herrod H G
Department of Pediatrics, University of Tennessee, Memphis 38163.
J Pediatr. 1992 Oct;121(4):516-22. doi: 10.1016/s0022-3476(05)81137-0.
We studied humoral immune function in 267 children with recurrent respiratory infections referred to our immunology clinic to determine the most appropriate immunologic studies for evaluating recurrent infections in children. Of this highly selected population, 58% had a partial deficiency in one or more of the major immunoglobulin isotypes or IgG subclasses (defined as at least 2 SD below the normal age-adjusted mean). In none of the patients was there a total absence of an immunoglobulin isotype. The most common abnormality was partial IgA deficiency, which was found in one third of the patients. Twenty-six patients had only partial IgG subclass deficiencies, of which 20 were deficiencies of a single subclass. IgG1 was an isolated partial defect in three patients, IgG3 in five patients, and IgG2 and IgG4 were selective partial defects in six patients each. Tetanus toxoid and pneumopolysaccharide type 3 were the most immunogenic of the immunogens tested; hyporesponsiveness to pneumococcal polysaccharide types 7, 9, and 14 was common. Nineteen percent of the patients with normal immunoglobulin concentrations who were tested had lower-than-expected antibody titers; 42% of those tested with partial isotype deficiencies had deficient antibody responses. Of 25 patients with selective partial IgG subclass deficiencies or combined IgG subclass deficiencies, eight had antibody deficiencies. Our findings indicate that a high proportion of children referred to immunology clinics for recurrent infection have a demonstrable immunologic abnormality. Selective IgG subclass deficiency or a combined IgG subclass deficiency without an associated deficiency in a major immunoglobulin isotype is unusual. Identification of such patients is not predictive of the capacity to form antibodies to the antigens tested in this study and, in our opinion, adds little to the initial evaluation of immune function in such children.
我们对267名因反复呼吸道感染前来我院免疫科就诊的儿童进行了体液免疫功能研究，以确定评估儿童反复感染最合适的免疫学检查项目。在这一经过高度筛选的人群中，58%的儿童存在一种或多种主要免疫球蛋白同种型或IgG亚类部分缺陷（定义为至少低于正常年龄校正均值2个标准差）。所有患者均未出现某种免疫球蛋白同种型完全缺失的情况。最常见的异常是部分IgA缺陷，三分之一的患者存在该问题。26名患者仅存在部分IgG亚类缺陷，其中20名患者为单一亚类缺陷。3名患者存在孤立的IgG1部分缺陷，5名患者存在IgG3缺陷，IgG2和IgG4各有6名患者存在选择性部分缺陷。破伤风类毒素和3型肺炎多糖是所检测免疫原中免疫原性最强的；对7型、9型和14型肺炎球菌多糖反应低下很常见。在接受检测的免疫球蛋白浓度正常的患者中，19%的患者抗体滴度低于预期；在存在部分同种型缺陷的患者中，42%的患者抗体反应不足。在25名存在选择性部分IgG亚类缺陷或合并IgG亚类缺陷的患者中，8名患者存在抗体缺陷。我们的研究结果表明，因反复感染前来免疫科就诊的儿童中，很大一部分存在可证实的免疫异常。选择性IgG亚类缺陷或合并IgG亚类缺陷且主要免疫球蛋白同种型无相关缺陷的情况并不常见。识别这类患者并不能预测其针对本研究中所检测抗原产生抗体的能力，并且在我们看来，对这类儿童免疫功能的初始评估帮助不大。
