Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, Federal University of São Paulo, São Paulo, SP, Brazil.
Immunodeficiency Centre for Wales, University Hospital of Wales, Cardiff, Wales, UK.
J Clin Immunol. 2023 Nov;43(8):1873-1880. doi: 10.1007/s10875-023-01536-1. Epub 2023 Jul 28.
This study aimed to investigate the correlation between calculated globulin (CG, total protein level minus albumin level) and the gamma globulin fraction (Gamma), obtained from serum protein electrophoresis with serum IgG levels in adults (≥ 18 years).
Using linear regression models, analyses of CG and Gamma levels correlation with IgG levels in adults were performed. Receiver-operator curves were created to determine cutoff values and the respective sensitivity and specificity measures.
A total of 886 samples were analyzed. CG and Gamma were positively and statistically correlated with IgG levels (r = 0.4628 for CG, and = 0.7941 for Gamma, p < 0.0001 for both analyses). For the detection of hypogammaglobulinemia, i.e., IgG level below the reference value (6 g/L), a CG cutoff value of 24 g/L showed a sensitivity of 86.2% (95% CI 69.4-94.5) and a specificity of 92% (90.0-93.6). A Gamma cutoff value of 7.15 g/L yielded a sensitivity of 100% (88.3-100) and a specificity of 96.8 (95.3-97.8).
Both CG and Gamma levels determined by protein electrophoresis analysis may be used to screen for antibody deficiencies in adults, enabling earlier diagnosis of antibody deficiencies in a routine clinical setting.
本研究旨在探讨成人（≥18 岁）血清总蛋白减去白蛋白水平（CG）与血清蛋白电泳γ球蛋白（Gamma）与 IgG 水平之间的相关性。
采用线性回归模型，分析 CG 和 Gamma 水平与成人 IgG 水平的相关性。绘制受试者工作特征曲线，确定截断值及相应的敏感度和特异度指标。
共分析了 886 例样本。CG 和 Gamma 与 IgG 水平呈正相关且具有统计学意义（CG 的 r 值为 0.4628，Gamma 的 r 值为 0.7941，两者的 p 值均<0.0001）。为了检测低丙种球蛋白血症（即 IgG 水平低于参考值 6g/L），CG 的截断值为 24g/L 时，敏感度为 86.2%（95%CI 69.4-94.5），特异度为 92%（90.0-93.6）。Gamma 的截断值为 7.15g/L 时，敏感度为 100%（88.3-100），特异度为 96.8%（95.3-97.8）。
血清蛋白电泳分析所确定的 CG 和 Gamma 水平可用于筛查成人的抗体缺陷，有助于在常规临床环境中更早地诊断抗体缺陷。
