Division of Allergy, Immunology and Rheumatology, Department of Pediatrics, Federal University of São Paulo, São Paulo, Brazil.
Immunodeficiency Centre for Wales, University Hospital of Wales, Cardiff, United Kingdom.
Front Immunol. 2024 Oct 23;15:1495564. doi: 10.3389/fimmu.2024.1495564. eCollection 2024.
Calculated globulin (CG, total protein minus albumin levels) correlate well with IgG levels and has been proposed as a suitable screening method for individuals with primary antibody deficiencies (PADs). We aimed to show the correlation of CG with IgG levels in children and adolescents, utilizing a common method for albumin measurement, bromocresol green.
Individuals from two Allergy and Immunology clinics were invited to participate. Inclusion criteria were age < 18, stable conditions, and signed informed consent. We included 1084 individuals. Immunoglobulin G values were determined by immunoturbidimetry; the colorimetric bromocresol green method and the Architect Biuret method were utilized for the albumin and total protein (TP) measurements, respectively.
A total of 1084 individuals were included in the analysis and divided into 4 age groups (0 to <1 year, 1 to <4 years, 4 to <10 years, and 10 to <18 years). For all patients, the mean age was 6.1 (± 5) years old, the mean IgG was 9.4 (± 4.7) g/L, and CG was 23.7 (± 5.9) g/L. The most frequent diagnosis were respiratory allergies, followed by inborn errors of immunity. IgG and CG varied according to age group. Cutoff values for hypogammaglobulinemia varied from 13.8 g/L in children < 1 year to 23.1 g/L in children and adolescents aged 10 to <18 years. CG sensitivity varied from 70.9% in children aged 1 to <4 years old to 95.8% in children 4 to <10. Specificity ranged from 87.5% in children 4 to <10 years old to 100% in children and adolescents aged 10 to <18 years.
CG is a suitable screening test for hypogammaglobulinemia in children less than 18 years of age.
计算球蛋白（CG，总蛋白减去白蛋白水平）与 IgG 水平相关性良好，已被提议作为原发性抗体缺陷（PAD）个体的合适筛选方法。我们旨在利用溴甲酚绿这一常用白蛋白测量方法，显示 CG 与儿童和青少年 IgG 水平的相关性。
邀请两个过敏和免疫学诊所的个体参与。纳入标准为年龄<18 岁、病情稳定且签署知情同意书。共纳入 1084 名个体。免疫球蛋白 G 值通过免疫比浊法测定；分别使用比色溴甲酚绿法和Architect 双缩脲法测定白蛋白和总蛋白（TP）。
共纳入 1084 名个体进行分析，并分为 4 个年龄组（0 至<1 岁、1 至<4 岁、4 至<10 岁和 10 至<18 岁）。所有患者的平均年龄为 6.1（±5）岁，平均 IgG 为 9.4（±4.7）g/L，CG 为 23.7（±5.9）g/L。最常见的诊断是呼吸道过敏，其次是先天性免疫缺陷。IgG 和 CG 随年龄组而异。低丙种球蛋白血症的截断值从<1 岁儿童的 13.8g/L 到 10 至<18 岁儿童和青少年的 23.1g/L 不等。CG 敏感性从 1 至<4 岁儿童的 70.9%到 4 至<10 岁儿童的 95.8%不等。特异性从 4 至<10 岁儿童的 87.5%到 10 至<18 岁儿童和青少年的 100%不等。
CG 是<18 岁儿童低丙种球蛋白血症的一种合适的筛选试验。
