Background & Aims

In the context of the Italian severe acute respiratory syndrome coronavirus 2 vaccination program, liver transplant (LT) recipients were prioritized for vaccine administration, although the lower response to vaccines is a well-known problem in this population. We aimed to evaluate immunogenicity of BNT162b2 mRNA vaccine in LT recipients and healthy controls and to identify factors associated with negative response to vaccine.

Methods

In a cohort of adult patients with LT, we prospectively evaluated the humoral response (with anti-Spike protein IgG-LIAISON SARS-CoV-2 S1/S2-IgG chemiluminescent assay) at 1 and 3 months after 2-dose vaccination. A group of 307 vaccinated health care workers, matched by age and sex, served as controls.

Results

Overall, 492 LT patients were enrolled (75.41% male; median age, 64.85 years). Detectable antibodies were observed in the 75% of patients, with a median value of 73.9 AU/mL after 3 months from 2-dose vaccination. At multivariable analysis, older age (>40 years; P = .016), shorter time from liver transplantation (<5 years; P = .004), and immunosuppression with antimetabolites (P = .029) were significantly associated with non-response to vaccination. Moreover, the LT recipients showed antibody titers statistically lower than the control group (103 vs 261 AU/mL; P < .0001). Finally, in both controls and LT patients, we found a trend of inverse correlation between age and antibody titers (correlation coefficients: −0.2023 and −0.2345, respectively).

Conclusions

Three months after vaccination, LT recipients showed humoral response in 75% of cases. Older age, shorter time from transplantation, and use of antimetabolites were factors associated with non-response to vaccination, and LT recipients at risk of non-response to vaccination needed to be kept under close monitoring.

中文翻译：

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肝移植受者对 2 剂 BNT162b2 mRNA COVID-19 疫苗接种的体液反应

背景与目标

在意大利严重急性呼吸综合征冠状病毒 2 疫苗接种计划的背景下，肝移植 (LT) 接受者优先接种疫苗，尽管对疫苗的反应较低是该人群中众所周知的问题。我们旨在评估 BNT162b2 mRNA 疫苗在 LT 接受者和健康对照中的免疫原性，并确定与疫苗负反应相关的因素。

方法

在一组成年 LT 患者中，我们前瞻性地评估了 2 剂疫苗接种后 1 个月和 3 个月的体液反应（使用抗尖峰蛋白 IgG-LIAISON SARS-CoV-2 S1/S2-IgG 化学发光测定）。一组 307 名接种疫苗的医护人员，按年龄和性别匹配，作为对照。

结果

总体而言，共招募了 492 名 LT 患者（75.41% 为男性；中位年龄为 64.85 岁）。在 75% 的患者中观察到可检测到的抗体，接种 2 剂疫苗 3 个月后的中位值为 73.9 AU/mL。在多变量分析中，年龄较大（>40 岁；P  = .016）、肝移植时间较短（<5 岁；P  = .004）和抗代谢物免疫抑制（P  = .029）与无应答显着相关到疫苗接种。此外，LT 接受者的抗体滴度在统计学上低于对照组（103 vs 261 AU/mL；P< .0001)。最后，在对照组和 LT 患者中，我们发现年龄和抗体滴度之间存在负相关趋势（相关系数分别为 -0.2023 和 -0.2345）。

结论

接种疫苗三个月后，LT 接受者在 75% 的病例中表现出体液反应。年龄较大、移植时间较短和使用抗代谢物是与疫苗接种无反应相关的因素，需要密切监测有对疫苗接种无反应风险的 LT 受者。