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.

Seroprevalence rates and molecular characterization of hepatitis E virus (HEV) prevalent in the Lithuanian human population has not yet been evaluated. Immunosuppressed individuals have been recognized as a risk group for chronic hepatitis due to HEV genotype 3 (HEV-3) infections. The objectives of the present study were to determine prevalence rates of anti-HEV antibodies among inflammatory bowel disease (IBD) patients and solid organ transplant (SOT) recipients, to isolate and characterize HEV strain present in the Lithuanian human population, and to investigate its capacity to infect non-human primate (MARC-145 and Vero), swine (PK-15) and murine (Neuro-2a) cells in vitro. In the present study, the significant difference of anti-HEV IgG prevalence between healthy (3.0% (95% CI 0–6.3)) and immunosuppressed individuals (12.0% [95% CI 8.1–15.9]) was described. Moreover, our findings showed that anti-HEV IgG seropositivity can be significantly predicted by increasing age (OR = 1.032, p < 0.01), diagnosis of IBD (OR = 4.541, p < 0.01) and reception of SOT (OR = 4.042, <0.05). Locally isolated HEV strain clustered within genotype 3i subtype of genotype 3 and was capable of infecting MARC-145 cells. This study demonstrates higher HEV seroprevalence in the risk group compared to healthy control individuals without confidence interval overlap. The high level of genetic homology between human and animal strains in Lithuania and the capacity of locally isolated strains to infect cells of non-human origin suggests its potential for zoonotic transmission.

Background and Objectives: Early improvements to graft function are crucial for good outcomes in kidney transplantation (kTx). Various factors can influence early graft function. This study aimed to evaluate the pre- and post-transplant hydration statuses of kTx recipients using bioimpedance analysis (BIA) and lung ultrasonography (LUS) and to investigate the hydration status’ relationship with the function of the transplanted kidney during the first year after transplantation. Materials and Methods: This observational prospective cohort study included deceased kidney recipients transplanted in the Hospital of the Lithuanian University of Health Sciences between September 2016 and January 2023. BIA and LUS were performed before transplantation, on days 3 and 7, and at discharge. Data on recipient and donor clinical characteristics were collected. Graft function was evaluated according to the serum creatinine reduction ratio and the need for dialysis. Hydration status was evaluated by calculating B-lines (BL) on LUS and the ratio of extracellular/total body water on BIA. Results: Ninety-eight kTx recipients were included in the study. Patients with immediate graft function (IGF) were compared to those with slow or delayed graft function (SGF + DGF). Recipients in the SGF + DGF group had a higher sum of BL on LUS before transplantation. After transplantation in early postoperative follow-up, both groups showed hyperhydration as determined by BIA and LUS. After one year, recipients with no BL before transplantation had better graft function than those with BL. Logistic regression analysis showed that having more than one BL in LUS was associated with a 2.5 times higher risk of SGF or DGF after transplantation. Conclusions: This study found that lung congestion detected by LUS before kTx was associated with slower graft recovery and worse kidney function after 1 year. Meanwhile, the hyperhydration status detected by BIA analysis did not correlate with the function of the transplanted kidney.