Humoral response to SARS-CoV-2 is well preserved and symptom dependent in kidney transplant recipients

Abstract

Data on the immune response to SARS‐CoV‐2 in kidney transplant recipients are scarce. Thus, we conducted a single‐center observational study to assess the anti‐SARS‐CoV‐2 IgG seroprevalence in outpatient kidney transplant recipients (KTR; n = 1037) and healthcare workers (HCW; n = 512) during the second wave of the COVID‐19 pandemic in fall 2020 and evaluated the clinical variables affecting antibody levels. Antibodies against S1 and S2 subunit of SARS‐CoV‐2 were evaluated using immunochemiluminescent assay (cut off 9.5 AU/ml, sensitivity of 91.2% and specificity of 90.2%). Anti‐SARS‐CoV‐2 IgG seroprevalence was lower in KTR than in HCW (7% vs. 11.9%, p = .001). Kidney transplant recipients with SARS‐CoV‐2 infection were younger (p = .001) and received CNI‐based immunosuppression more frequently (p = .029) than seronegative KTR. Anti‐SARS‐CoV‐2 IgG positive symptomatic KTR had a higher BMI (p = .04) than asymptomatic KTR. Interestingly, anti‐SARS‐CoV‐2 IgG levels were higher in KTR than in HCW (median 31 AU/ml, IQR 17–84 vs. median 15 AU/ml, IQR 11–39, p < .001). The presence of moderate to severe symptoms in KTR was found to be the only independent factor affecting IgG levels (Beta coefficient = 41.99, 95% CI 9.92–74.06, p = .011) in the multivariable model. In conclusion, KTR exhibit a well‐preserved symptom‐dependent humoral response to SARS‐CoV‐2 infection.

Determinants of Immune Response to Anti–SARS-CoV-2 mRNA Vaccines in Kidney Transplant Recipients: A Prospective Cohort Study

“…Furthermore, we recently showed that KTRs mounted a similar level of anti-SARS-CoV-2 antibodies compared with healthcare workers as a result of natural immunization. 10 Using an identical antibody detection method in both studies, the observed SARS-CoV-2 antibody levels after a natural infection 10 were lower than in KTRs who were first infected with SARS-CoV-2 and later received a vaccine. Therefore, mRNA vaccines may serve as a booster of the immune response primed by natural immunization when immunosuppression is absent or reduced.…”

“…In other studies, participants were screened for SARS-CoV-2 antibodies. However, even serological screening has its limitations, as varying proportions of SARS-CoV-2 positive KTRs will not mount antibodies 10,36 or the antibodies might decrease over time. Therefore, even individuals with negative SARS-CoV-2 antibodies might carry an immune memory and bias the measurements.…”

COVID-19 and solid organ transplantation: Finding the right balance

“…Twelve studies concerning natural immunity after COVID-19 infection have been included. [ [101] , [102] , [103] , [104] , [105] , [106] , [107] , [108] , [109] , [110] , [111] , [112] ]…”

“…Overall, the majority of SOT patients is able to mount a humoral response to SARS-COV-2. [ [101] , [102] , [103] , [104] , [105] , [106] , [107] , [108] , 111 ]…”

“…In addition, the humoral response to SARS-COV-2 is comparable to immunocompetent patients [ [102] , [103] , [104] , [105] , [106] ]. In the study of Zervou et al, 83.6% of the 61 SOT patients had seropositive IgG results after two months.…”