The Impact of Frailty Syndrome on Humoral Response to SARSCoV- 2 mRNA Vaccines in Older Kidney Transplant Recipients

ABSTRACT

Purpose: Advanced age is associated with impaired humoral immune response to SARS-CoV-2 mRNA vaccines in kidney transplant recipients (KTR), however mechanisms are poorly understood. Frailty syndrome assessment in geriatric KTR may reveal the most vulnerable population. Method(s) This is the subcohort analysis of prospective study (NCT04832841) dealing with seroconversion after SARS-CoV-2 mRNA vaccination. In 101 KTR aged 70+ who were SARS-CoV-2 naive, the Fried frailty components were evaluated. Antibodies against S1 and S2 subunit of SARS-CoV-2 were evaluated >14 days after second dose of mRNA vaccines using immunochemiluminescent assay (cut off 9.5 AU/ml, sensitivity of 91.2% and specificity of 90.2%). The clinical variables affecting the humoral response were analyzed by multivariable binary regression model based on results of univariable analysis. Result(s) The seroconversion after SARS-CoV-2 vaccination was observed in 33 out of 101 (33%) KTR. In the univariable regression model, eGFR (OR=1.03, p=0.001), MMF-free immunosuppression (OR=4.32, p=0.002), physical inactivity (OR=0.36, p=0.039), grip strength (OR=1.05, p=0.045), male gender (OR=2.09, p=0.09), and Fried frailty score (OR=0.74, p=0.09) were associated with seroconversion. Multivariable binary logistic regression model adjusted for KTR age and gender retained as independent significant predictors for seroconversion the Fried frailty cumulative score (OR=0.6, p=0.048), eGFR (OR=1.05, p<0.001), MMF-free immunosuppression (OR=8.25, p=0.001) and longer follow-up from transplantation (OR=1.01, p=0.021). Conclusion(s) The frailty but not age itself is associated with impaired humoral response to SARS-CoV-2 mRNA vaccines in KTR. Intervention to reduce physical inactivity prior to vaccination may improve seroconversion rate in elderly KTR.