Purpose

COVID-19 disease may result in a severe multisystem inflammatory syndrome in children (MIS-C), which in turn may alter thyroid function (TF). We assessed TF in MIS-C, evaluating its impact on disease severity.

Methods

We retrospectively considered children admitted with MIS-C to a single pediatric hospital in Milan (November 2019–January 2021). Non-thyroidal illness syndrome (NTIS) was defined as any abnormality in TF tests (FT3, FT4, TSH) in the presence of critical illness and absence of a pre-existing hormonal abnormality. We devised a disease severity score by combining severity scores for each organ involved. Glucose and lipid profiles were also considered. A principal component analysis (PCA) was performed, to characterize the mutual association patterns between TF and disease severity.

Results

Of 26 (19 M/7F) patients, median age 10.7 (IQR 5.8–13.3) years, 23 (88.4%) presented with NTIS. A low FT3 level was noted in 15/23 (65.3%), while the other subjects had varying combinations of hormone abnormalities (8/23, 34.7%). Mutually correlated variables related to organ damage and inflammation were represented in the first dimension (PC1) of the PCA. FT3, FT4 and total cholesterol were positively correlated and characterized the second axis (PC2). The third axis (PC3) was characterized by the association of triglycerides, TyG index and HDL cholesterol. TF appeared to be related to lipemic and peripheral insulin resistance profiles. A possible association between catabolic components and severity score was also noted.

Conclusions

A low FT3 level is common among MIS-C. TF may be useful to define the impact of MIS-C on children’s health and help delineate long term follow-up management and prognosis.

中文翻译：

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儿童非甲状腺疾病综合征和 SARS-CoV-2 相关多系统炎症综合征

目的

COVID-19 疾病可能导致儿童出现严重的多系统炎症综合征 (MIS-C)，进而可能改变甲状腺功能 (TF)。我们评估了 MIS-C 中的 TF，评估其对疾病严重程度的影响。

方法

我们回顾性研究了米兰一家儿科医院（2019 年 11 月至 2021 年 1 月）收治的 MIS-C 患儿。非甲状腺疾病综合征 (NTIS) 被定义为在存在危重疾病且没有预先存在的激素异常的情况下 TF 测试 (FT3、FT4、TSH) 的任何异常。我们通过结合每个相关器官的严重程度评分来设计疾病严重程度评分。还考虑了葡萄糖和脂质谱。进行了主成分分析 (PCA)，以表征 TF 和疾病严重程度之间的相互关联模式。

结果

在 26 名 (19 M/7F) 患者中，中位年龄 10.7 (IQR 5.8-13.3) 岁，23 名 (88.4%) 出现 NTIS。在 15/23 (65.3%) 中注意到低 FT3 水平，而其他受试者有不同的激素异常组合 (8/23, 34.7%)。与器官损伤和炎症相关的相互关联的变量在 PCA 的第一维 (PC1) 中表示。FT3、FT4 和总胆固醇呈正相关，并以第二轴 (PC2) 为特征。第三轴 (PC3) 的特点是甘油三酯、TyG 指数和 HDL 胆固醇的关联。TF 似乎与脂血和外周胰岛素抵抗谱有关。还注意到分解代谢成分与严重程度评分之间可能存在关联。

结论

MIS-C 中常见的 FT3 水平较低。TF 可能有助于定义 MIS-C 对儿童健康的影响，并有助于描述长期随访管理和预后。