Background

Despite studies on low immunoglobulin G (IgG) levels in critically ill patients, their association with clinical outcomes in sepsis patients remains disputed. Herein, we determined the association between low IgG levels and clinical outcomes and investigated the 28-day mortality in patients with low IgG levels.

Methods

We retrospectively identified 238 patients whose serum IgG levels were measured upon intensive care unit admission using medical record data collected between January 2013 and August 2018. We extracted data on patient characteristics, severity scores (APACHE II, SOFA score), neutrophil-lymphocyte ratio (NLR), procalcitonin levels, and serum IgG levels and calculated the cut-off value for the IgG level according to the evaluated clinical outcomes. The primary outcome was 28-day mortality.

Results

There were no significant differences in NLR and procalcitonin levels between survivors and non-survivors; serum IgG levels were significantly higher in survivors than in non-survivors (P = 0.004). A serum IgG cut-off value of 670 mg/dL was calculated from receiver operating characteristic curve analysis, and serum IgG levels significantly predicted survival with an area under the curve of 0.63 (95% CI, 0.54–0.72) (P = 0.004). Patients with low IgG levels (<670 mg/dL) had significantly higher mortality rates than those with normal IgG levels (≥670 mg/dL) (P < 0.001).

Conclusion

Our results reveal that low IgG levels (<670 mg/dL) in critically ill patients are associated with poor clinical outcomes related to 28-day mortality. In patients with sepsis, low IgG levels could be a predictor of poor outcome.

中文翻译：

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低免疫球蛋白 G 水平与败血症和败血性休克患者的不良预后相关

背景

尽管对危重患者的低免疫球蛋白 G (IgG) 水平进行了研究，但它们与败血症患者临床结果的关联仍然存在争议。在此，我们确定了低 IgG 水平与临床结果之间的关联，并调查了低 IgG 水平患者的 28 天死亡率。

方法

我们使用 2013 年 1 月至 2018 年 8 月期间收集的病历数据，回顾性确定了 238 名在重症监护病房入院时测量血清 IgG 水平的患者。我们提取了患者特征、严重程度评分（APACHE II，SOFA 评分）、中性粒细胞 - 淋巴细胞比率（ NLR)、降钙素原水平和血清 IgG 水平，并根据评估的临床结果计算 IgG 水平的临界值。主要结果是 28 天死亡率。

结果

幸存者和非幸存者的 NLR 和降钙素原水平没有显着差异；幸存者的血清 IgG 水平显着高于非幸存者（P  = 0.004）。根据受试者工作特征曲线分析计算得出的血清 IgG 临界值为 670 mg/dL，血清 IgG 水平显着预测存活，曲线下面积为 0.63（95% CI，0.54–0.72）（P  = 0.004） . IgG水平低（<670 mg/dL）患者的死亡率显着高于IgG水平正常（≥670 mg/dL）患者（P  < 0.001）。

结论

我们的结果表明，危重患者的低 IgG 水平 (<670 mg/dL) 与与 28 天死亡率相关的不良临床结果相关。在脓毒症患者中，低 IgG 水平可能是预后不良的预测因素。