Long‑term microvascular alterations in kidney transplant recipients after SARS‑CoV‑2 infection

INTRODUCTION: The long-term cardiovascular consequences of COVID-19 in organ recipients have been insufficiently studied. OBJECTIVE: The aim of our study was to evaluate the association between COVID-19 and microvascular abnormalities in kidney transplant recipients 8 weeks after SARS-CoV-2 infection.  Patients and methods: The study population consisted of 54 kidney transplant recipients,  and was divided into two subgroups: patients with a history of COVID-19 (n = 35) and patients without a history of COVID-19 (n = 21). We assessed both the structure and function of microcirculation. RESULTS: The study group was aged 47.6 (12.7) years and included 54% of women. Patients with and without a history of COVID-19 did not differ in baseline characteristics. Compared to patients without a history of COVID-19, subjects after SARS-CoV-2 infection had substantially lower values of ischemic response: IRmax; 7.0 (5.0-8.7) vs. 9.6 (8.8-11.5), P = 0.04; IR index 3.1 (2.3-4.2) vs 7.2 (5.2-8.2), P = 0.01), with the IR index further confirmed in a multivariable analysis. Logistic regression analysis showed that estimated glomerular filtration rate was linked to microvascular functional decline, expressed by a poorer normoxia oscillatory index (odds ratio 0.95, CI 0.90-0.99, P = 0.047). C-reactive protein was associated with arterioles' wall thickness (R = 0.42, P = 0.02) and wall-to-lumen ratio (R = 0.48, P = 0.01). CONCLUSION: We documented that microvascular dysfunction was associated with SARS-CoV-2 infection and is detectable 8 weeks after the acute phase in kidney transplant recipients.