Introduction
Celiac disease (CD) is the most common autoimmune disease (AD) of the small intestine, affecting 1-2% of the population globally. It is characterized by the serological presence of autoantibodies (Abs), tissue transglutaminase antibody (tTGA), immunoglobulin (Ig) A, and IgG. Production of antibodies against SARS-CoV-2 after infection with the virus or vaccination is not well understood, especially among CD patients. The goal of this study was to measure the IgG antibodies in Jordanian patients infected with or vaccinated against the SARS-CoV-2 virus with different types of vaccines (Pfizer- BioNTech BNT162b2, Sinopharm BBIBP-CorV or Oxford-AstraZeneca ChAdOx1-S) and compare them with the levels in non-celiac controls. IgG levels induced by different vaccines were also compared.

Material and methods
The data for this cross-sectional study were obtained via a survey, whereby respondents were identified through convenience sampling. The healthy controls were given Questionnaire A while CD patients completed Questionnaire B. The blood samples from all participants were tested for the COVID-19 nucleocapsid protein (NP) IgG serum levels for participants previously infected with SARS-CoV-2, and spike (S) protein (S1/S2) IgG serum levels for vaccine recipients.

Results
The study involved 116 individuals, 60 (51.7%) of whom were CD patients. The NP IgG serum levels in the infected and S1/S2 IgG levels in the vaccinated CD patients were significantly lower than the levels in controls (48.3 ±44.5 vs. 81.1 ±34.4 and 49 ±45.8 vs. 75.7 ±38.6, p = 0.002). Moreover, only the Pfizer vaccine induced significantly more IgG antibodies in controls compared to CD patients (88.8 ±29.1 vs. 58.3 ±45.4, p = 0.01). On the other hand, the IgG levels were significantly higher in CD patients who received the Pfizer relative to the AstraZeneca vaccine (58.3 ±45.5 vs. 13.0 ±23.6, p = 0.03). After adjusting for presence of CD, age, sex, body mass index (BMI), comorbidities, vaccine type, smoking, gluten adherence, and time since infection or vaccination, SARS-CoV-2 S1/S2 IgG Abs and/or NP IgG Abs positivity was significantly associated with CD absence and negatively with vaccine type (AstraZeneca) with the odds ratios (ORs) of 9.6 (95% CI = 1.5-59.2, p = 0.015) and 0.03 (95% CI = 0.004-0.244. p = 0.001), respectively.

Conclusions
We concluded that patients with CD had lower SARS-CoV-2 S1/S2 IgG Abs and NP IgG Abs levels than controls, and CD patients who received the Pfizer vaccine had higher IgG levels than patients who received the AstraZeneca vaccine. We recommend that further research be conducted to address the dynamics of the antibody responses in CD patients regarding COVID-19 infection.



中文翻译：

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乳糜泻患者对 COVID-19 感染或疫苗接种的体液免疫反应

简介
腹腔疾病 (CD) 是最常见的小肠自身免疫性疾病 (AD)，影响全球 1-2% 的人口。其特征在于自身抗体 (Abs)、组织转谷氨酰胺酶抗体 (tTGA)、免疫球蛋白 (Ig) A 和 IgG 的血清学存在。感染病毒或接种疫苗后抗 SARS-CoV-2 抗体的产生尚不清楚，尤其是在 CD 患者中。本研究的目的是用不同类型的疫苗（Pfizer-BioNTech BNT162b2、Sinopharm BBIBP-CorV 或 Oxford-AstraZeneca ChAdOx1-S）测量感染或接种 SARS-CoV-2 病毒的约旦患者的 IgG 抗体和将它们与非腹腔控制的水平进行比较。还比较了不同疫苗诱导的 IgG 水平。

材料与方法
这项横断面研究的数据是通过调查获得的，受访者是通过方便抽样确定的。健康对照者接受问卷 A，而 CD 患者完成问卷 B。对所有参与者的血液样本进行了 COVID-19 核衣壳蛋白 (NP) IgG 血清水平检测，检测了之前感染过 SARS-CoV-2 的参与者的血清水平，以及尖峰 (S) ) 疫苗接种者的蛋白质 (S1/S2) IgG 血清水平。

结果
该研究涉及 116 人，其中 60 人 (51.7%) 是 CD 患者。受感染的 NP IgG 血清水平和接种疫苗的 CD 患者的 S1/S2 IgG 水平显着低于对照组的水平（48.3 ±44.5 对 81.1 ±34.4 和 49 ±45.8 对 75.7 ±38.6，p = 0.002） . 此外，与 CD 患者相比，只有辉瑞疫苗在对照组中诱导出明显更多的 IgG 抗体（88.8 ±29.1 对 58.3 ±45.4，p = 0.01）。另一方面，接受辉瑞疫苗的 CD 患者的 IgG 水平明显高于阿斯利康疫苗（58.3 ±45.5 对 13.0 ±23.6，p = 0.03）。在针对 CD 的存在、年龄、性别、体重指数 (BMI)、合并症、疫苗类型、吸烟、麸质依从性以及感染或接种疫苗后的时间进行调整后，

结论
我们得出结论，CD 患者的 SARS-CoV-2 S1/S2 IgG Abs 和 NP IgG Abs 水平低于对照组，接受辉瑞疫苗的 CD 患者的 IgG 水平高于接受阿斯利康疫苗的患者。我们建议进行进一步的研究，以解决 CD 患者对 COVID-19 感染的抗体反应动态。