ABSTRACT
Purpose: Recent data has shown poor antibody response to SARS-CoV-2 vaccination among adult kidney transplant (tx) recipients, with seroconversion ranging between 22%-58% after two mRNA vaccine doses. Here, we evaluated the antibody and T cell response to SARS-CoV-2 vaccination and evaluate the effects of intensified immunosuppression on such response in pediatric (ped) kidney tx recipients. Method(s): Between April and November 2021, 31 ped renal tx patients (pts)aged 13-22 years old had SARS-CoV-2 spike IgG assessment after receiving 2 doses of SARS-CoV-2 mRNA or 1 dose of viral vector vaccine. Pts were evaluated by their level of immunosuppression: A) standard immunosuppression (tacrolimus, mycophenolate mofetil +/- steroids) or B) intensified immunosuppression (standard immunosuppression + solumedrol pulse, IVIG, rituximab, and/or tocilizumab within 11 months prior to and up to 5 months after SARS-CoV-2 vaccination). A subgroup of 18 pts had SARS-CoV-2 Tc assessment post-vaccination. Result(s): 23 of 31 (74.2%) pts seroconverted at a median assessment time of 83 days (IQR 43-124) post-vaccination. There was no difference in the use of steroid-based or steroid-free immunosuppression between the two groups or the type of vaccine received (Table 1). 15 of 17 (88.2%) of those who received standard immunosuppression seroconverted post-vaccination compared to 8 of 14 (57.1%) in those who received intensified immunosuppression (Table 1;p = 0.10). In a subgroup of pts who had SARS-CoV-2 spike-specific Tc testing, 7 of 7 (100%) in the standard immunosuppression group had positive Tc compared to 7 of 11 (63.6%) in the intensified immunosuppression group (Table 1, p = 0.12). There was no leukopenia or difference in the WBC count in either group at the time of Tc testing (Table 1;p = 0.97). No pts developed symptomatic SARS-CoV-2 infection. Conclusion(s): Ped renal tx recipients appear to have higher rates of seroconversion after the standard 2-dose mRNA or 1-dose viral vector SARS-CoV-2 vaccination compared to adult renal tx recipients. The intensified immunosuppression group appears to have a trend towards lower SARS-CoV-2 spike IgG and Tc conversion, however, results are limited by the small sample size. Larger studies are needed to better understand the humoral and cellular response to SARS-CoV-2 vaccination in this group. (Figure Presented).
ABSTRACT
Purpose: As of late November 2020, there have been 61.5 million cases of SARSCoV- 2 (COVID-19) worldwide resulting in 1.44 million deaths. Despite the outstanding number of cases there is limited data on the incidence of SARS-CoV-2 infection, both symptomatic and asymptomatic, among pediatric (ped) kidney transplant (KTx) patients (pts) and their outcomes. Methods: Between March and November 2020, 33 SARS-CoV-2 RNA RT-PCR tests were performed among 23 ped KTx pts who were maintained on mycophenolate mofetil, tacrolimus, +/- steroids. Pts were tested for SARS-CoV-2 if they had any COVID-19 symptoms, had positive COVID-19 contact, or needed SARS-CoV-2 testing for admission to the hospital or for pre-procedural clearance. No pts were tested more than once during each encounter. Results: Of the 33 SARS-CoV-2 tests performed, 7 (21.2%) were due to pts having one or several COVID-19-like symptoms, while 26 (78.8%) were for pts who had positive COVID-19 contact or needed SARS-CoV-2 testing for admission to the hospital or for pre-procedural clearance. Of the 33 tests performed, there were 3 (9.1%) confirmed cases of COVID-19. Two of the 3 SARS-CoV-2 positive cases had symptoms consistent with infection, compared to one asymptomatic case (p = 0.11). The two positive cases with symptoms were on steroid-free immunosuppression, had estimated GFR (eGFR) of 101 and 60 ml/min/1.73m2, and were 0.9 and 3.1 years post-Tx, respectively. The one asymptomatic case was on steroid-based immunosuppression, had eGFR 85, and was 0.9 years post-Tx. No pts who tested positive for SARS-CoV-2 required hospitalizations. Five of the 7 pts (71.4%) with symptoms consistent with COVID-19 were eventually diagnosed with a different infection (bacterial and/or viral) and all required admission for management. Conclusions: There is a low rate of asymptomatic SARS-CoV-2 (COVID-19) infection among our ped KTx cohort. When infected with SARS-CoV-2, ped KTx pts tend to present with minimal symptoms. In this small cohort, there appears to be no correlation between the time since Tx, eGFR, and the maintenance immunosuppression in relation to whether or not pts were more likely to have symptoms or have more severe disease if infected with SARS-CoV-2. Ped KTx pts with symptoms concerning for COVID-19 with clinical indications for admission were more likely to have alternative diagnoses. Larger studies are needed to understand the prevalence and impact of SARS-CoV-2 infection in the ped KTx population.