Immune Response after SARS-CoV-2 Vaccination in Kidney Transplant Patients.

Background and Objectives: The prospective study was conducted to evaluate humoral and cellular immune responses after two doses of BNT162b2 (Pfizer-BioNTech) vaccine and possible relation with other factors (medication, etc.) in kidney transplant patients. Materials and Methods: Out of 167 vaccinated patients, 136 agreed to a follow-up visit three to six weeks after vaccination. Results: Only 39 patients (29%) developed antibody response against SARS-CoV-2 (≥35.2 binding antibody units (BAU)/mL) after full vaccination. Multivariate binary logistic regression analysis showed that predictive factors for good antibody response to the COVID-19 vaccine were better kidney function, higher hemoglobin level, and no use of mycophenolate mofetil for immunosuppression. For seropositive kidney transplant patients there was a significant negative correlation between anti-SARS-CoV-2 antibody titer and CD4/CD8 ratio (Spearman's correlation coefficient -0.4, p = 0.02), percentage of CD19+ cells (r = -0.37, p = 0.02), and a positive correlation with percentage of CD8+ cells (r = 0.4, p = 0.01). There was an increase of total leucocyte count after vaccination in the total studied population, and in the group of responders. Conclusions: Only one third of kidney transplant patients develop sufficient antibody responses after full COVID-19 vaccination with Pfizer-BioNTech. Better kidney function, higher hemoglobin level, and no use of mycophenolate mofetil for immunosuppression increases the adequacy of response. The antibody titers correlated positively with relative number of CD8+ cells and negatively with CD4/CD8 ratio in responders.

Factors influencing renal graft survival: 7-Year experience of a single center.

BACKGROUND AND OBJECTIVE: The demand for kidney transplants exceeds the existing supply. This leads to a recently growing interest of research in the area of factors that could prolong graft long-term outcomes and survival. In Lithuania, approximately 90% of kidney transplantations are from deceased donors. Donor organs are received and shared only inside the country territory in Lithuania; therefore, donor data is accurate and precise. This study was performed to present particularities of kidney transplantation data in Lithuania and to identify the effect of donor and recipient factors and histologic findings on renal graft outcomes. The aim of this study was to identify the effect of donor and recipient factors and histologic findings on renal graft outcomes. MATERIALS AND METHODS: We analyzed the influence of deceased donor and recipient factors and histological findings on the graft function in 186 renal transplant patients. Graft survival was estimated within the first year after transplantation. RESULTS: The donors and recipients were older in worse eGFR group 1 year after transplantation. Dissimilarity of degree of glomerulosclerosis (GS), interstitial fibrosis (IF) and arteriolar hyalinosis (AH) were significant in inferior and superior renal function groups (GS >20% 11.4 vs. 0%, P=0.017; IF 9.3 vs. 0%, P=0.034; AH 69 vs. 26.2%, P<0.001). Nine independent variables were significantly associated with a worse renal transplant function 1 year posttransplantation: AH (OR=6.287, P<0.001), an episode of urinary tract infection (OR=2.769, P=0.020), acute graft rejection (OR=3.605, P=0.037), expanded criteria (OR=4.987, P=0.001), female gender donors (OR=3.00, P=0.014), cerebrovascular disease caused donor brain death (OR=5.00, P=0.001), donor's age (OR=1.07, P<0.001), and recipient's age (OR=1.047, P=0.022). Worse renal graft survival 1 year posttransplantation was associated with a delayed graft function and a higher level of glomerulosclerosis in time-zero biopsy. CONCLUSIONS: Donor factors, such as age, female gender, brain death of cerebrovascular cause and expanded criteria donor status had a significant negative impact on the renal graft function 1 year after transplantation. Recipients' age, urinary tract infection and acute graft rejection episodes after transplantation were associated with a worse kidney function 1 year after transplantation. Lower 1-year graft survival was related to a delayed graft function (DGF) and a higher degree of glomerulosclerosis.