Nettagul R, Visitsunthorn N, Vichyanond P
Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
J Med Assoc Thai. 2003 Jul;86(7):686-92.
Primary immunodeficiency diseases are not common in children. The possibility of an immunological defect should be considered in any individual with repeated infections. A definite diagnosis for immodeficiency is sometimes difficult to achieve because of overlapping clinical manifestations. Immunoglobulin subclass deficiency is an immunological deficiency disease with which, one or more IgG subclasses are deficient. T cell immunity is normal. Patients may develop recurrent bacterial and respiratory infections or could remain asymptomatic.
The authors report a case of immunoglobulin G subclass deficiency presenting initially as transient hypogammaglobulinemia of infancy.
A 2 month-old boy presented to Siriraj Hospital with a history of chronic protracted diarrhea, disseminated scabies and sepsis. On presentation, he had generalized scaly and maculopapular rash with no palpable lymph nodes. CBC revealed WBC 22,100 cells/cm3 with PMN 42 per cent, lymphocytes 38 per cent, Eosinophils 4 per cent, Basophil 2 per cent and platelets 254,000/cm3. The immunoglobulin levels were as follows: IgG 181 mg/dl, IgA < 6.6 mg/dl, IgM 26.3 mg/dl. Lymphocyte enumerations revealed CD4 of 2,433 cells/cm3 (N 1,460-5,160); CD8 4,682 cells/cm3 (N 650-2,450); CD19 1,588 cell/cm3 (N 500-1,500); CD16 230 cell/cm3 (N 573 +/- 264). The initial diagnosis was X-linked agammaglobulinemia vs common variable immunodeficiency disease. His diarrhea and five courses of sepsis responded well to antibiotics administration and courses of intravenous immunoglobulin (IVIG) replacement. His through IgG became normal at 2 years of age (after 12 months of IVIG). IVIG was stopped and the diagnosis was changed to transient hypogammaglobulinemia of infancy (THI). Nevertheless, during his 4 month follow-up he developed recurrent sinopulmonary infections (i.e, otitis media and pneumonia). Repeated immunoglobulin profile showed IgG 1,200 mg/dl, IgA 135 mg/dl, IgM 26 mg/dl, IgG subclass were IgG, 1,030 mg/dl (N 280-830), IgG2 30 mg/dl (N 40-2,400), IgG3 22 mg/dl (N 6-130), IgG4 3 mg/dl (N 3-120). A diagnosis of IgG2 subclass deficiency presenting early as transient hypogammaglobulinemia of infancy was then made. Treatment with monthly IVIG was reinitiated and the patient is currently doing well.
The authors present a case of IgG subclass deficiency presenting as transient hypogammaglbulinemia of infancy. Follow-up of the immune profile and clinical manifestation is necessary for a definite diagnosis.
原发性免疫缺陷病在儿童中并不常见。任何反复感染的个体都应考虑存在免疫缺陷的可能性。由于临床表现重叠，有时难以明确诊断免疫缺陷。免疫球蛋白亚类缺陷是一种免疫缺陷病，其中一种或多种IgG亚类缺乏。T细胞免疫正常。患者可能会反复发生细菌感染和呼吸道感染，也可能没有症状。
作者报告一例最初表现为婴儿期短暂性低丙种球蛋白血症的免疫球蛋白G亚类缺陷病例。
一名2个月大的男孩因慢性迁延性腹泻、播散性疥疮和败血症病史就诊于诗里拉吉医院。就诊时，他全身有鳞屑性斑丘疹，未触及淋巴结。血常规显示白细胞22,100个/立方厘米，中性粒细胞42%，淋巴细胞38%，嗜酸性粒细胞4%，嗜碱性粒细胞2%，血小板254,000个/立方厘米。免疫球蛋白水平如下：IgG 181毫克/分升，IgA<6.6毫克/分升，IgM 26.3毫克/分升。淋巴细胞计数显示CD4为2,433个/立方厘米（正常范围1,460 - 5,160）；CD8为4,682个/立方厘米（正常范围650 - 2,450）；CD19为1,588个/立方厘米（正常范围500 - 1,500）；CD16为230个/立方厘米（正常范围573±264）。初步诊断为X连锁无丙种球蛋白血症与常见变异型免疫缺陷病。他的腹泻和五个疗程的败血症对抗生素治疗和静脉注射免疫球蛋白（IVIG）替代治疗反应良好。他的总IgG在2岁时（IVIG治疗12个月后）恢复正常。停用IVIG，诊断改为婴儿期短暂性低丙种球蛋白血症（THI）。然而，在他4个月的随访期间，他出现了反复的鼻窦肺部感染（即中耳炎和肺炎）。重复的免疫球蛋白谱显示IgG 1,200毫克/分升，IgA 135毫克/分升，IgM 26毫克/分升，IgG亚类为IgG 1,030毫克/分升（正常范围280 - 830），IgG2 30毫克/分升（正常范围40 - 2,400），IgG3 22毫克/分升（正常范围6 - 130），IgG4 3毫克/分升（正常范围3 - 120）。随后诊断为早期表现为婴儿期短暂性低丙种球蛋白血症的IgG2亚类缺陷。重新开始每月一次的IVIG治疗，患者目前情况良好。
作者报告了一例表现为婴儿期短暂性低丙种球蛋白血症的IgG亚类缺陷病例。为明确诊断，有必要对免疫谱和临床表现进行随访。
