Serological Response and Clinical Protection of Anti-SARS-CoV-2 Vaccination and the Role of Immunosuppressive Drugs in a Cohort of Kidney Transplant Patients

Abstract

Vaccination against SARS-CoV2 represents a key weapon to prevent COVID-19, but lower response rates to vaccination have frequently been reported in solid organ transplant recipients. The aim of our study was to evaluate the rate of seroconversion to SARS-CoV-2 mRNA vaccines in a cohort of kidney transplant recipients and the potential role of the different immunosuppressive regimens. We conducted an observational retrospective cohort study in kidney transplant patients vaccinated for COVID-19. For each patient, we evaluated IgG anti-S-RBD SARS-CoV-2 titers immediately before the administration of first COVID-19 vaccination dose, 20 days after the first dose and 40 days after the second dose. Moreover, we evaluated the type of immunosuppressive treatment and the incidence of vaccine breakthrough SARS-CoV-2 infection. We enrolled 121 kidney transplant patients vaccinated for COVID-19. At the time of administration of the first vaccine dose, all patients had a negative antibody titer; only 4.1% had positive antibody titers 20 days after the first dose. More than half patients 62 (51%) had protective antibody titers 40 days after the second dose. A total of 18 Solid Organ Transplant Recipients (SOTRs) (14.9%) got a SARS-CoV-2 breakthrough infection during the study period. With regard to immunosuppressive regimen, patients on mycophenolate-based regimen (48.7%) showed the lowest antibody response rates (27.5%) compared to other regimens. Our study confirms that kidney transplant patients show a poor response to two doses of COVID-19 vaccination. Moreover, in our study the use of mycophenolate is significantly associated with a non-response to COVID-19 m-RNA vaccines.

Role of mTOR inhibitor in the cellular and humoral immune response to a booster dose of SARS-CoV-2 mRNA-1273 vaccine in kidney transplant recipients

“…Nevertheless, this beneficial effect of mTORi after two doses of vaccine was no maintained in the adjusted model in our cohort, findings also noted by Bae ( 33 ). Several authors found similar results with MPA and mTORi in different groups of patients who received two doses ( 33 – 37 ), even proposing the temporary suspension of treatment during the vaccination process ( 38 ).…”

Relationship Between Immune Response to Severe Acute Respiratory Syndrome Coronavirus 2 Vaccines and Development of Breakthrough Infection in Solid Organ Transplant Recipients: The CONTRAST Cohort

“…In addition, there was a statistically significant relationship between increasing titer categories and proportion with confirmed infection (Wilcoxon rank sum, P = .006) [ 10 ]. It is also worth mentioning that in other cohorts of SOT recipients with BI, patients with negative or non–high-level AbR had a higher risk of unfavorable outcomes in terms of mortality and hospitalization compared with patients with high-level AbR [ 11–13 ].…”