Background. Data about SARS-CoV-2 vaccines efficacy in renal transplant recipients (RTR) are lacking. Methods. To reveal predictors for humoral response to BNT162b2 vaccine among RTR, patients were divided into positive (N = 42) and negative (N = 78) response groups based on receptor-binding domain (RBD) immunoglobulin G (IgG) ≥1.1 and neutralizing antibodies (NA) ≥16 dilution versus RBD IgG <1.1 or NA <16, respectively. NA were detected using a SARS-CoV-2 pseudo-virus. Results. NA were detected in only 42 of 120 (35%) of RTR versus 197 of 202 (97.5%) immunocompetent controls ( P < 0.001). NA geometric mean titers in RTR were significantly lower versus the control group {83.7 (95% confidence interval [CI], 50.5-138.8) versus 482 (95% CI, 411-566), P < 0.001}. In a multivariable analysis, mycophenolic acid (MPA) dose and hemoglobin level were found to be independent predictors for antibody response in RTR. A positive response rate of 27% versus 63% was observed in patients on and off MPA, respectively. An increase in MPA dose by 1 mg/kg weight reduced the odds for a positive response by 17% (odds ratio = 0.83; 95% CI, 0.75-0.92; P < 0.001). Geometric mean titers for RBD IgG were significantly reduced as MPA daily dose increased. Hemoglobin blood level <13 g/dL reduced the antibody response by 63% ( P = 0.04). Pain at the injection site after the second vaccine dose was significantly higher in the responders versus nonresponders (20.5% versus 5.5%, P = 0.01). Conclusions. Only 35% of RTR develop NA to the BNT162b2 mRNA vaccine. MPA is a major suppressor of antibody response in RTR.

This is the first study to evaluate changes in thyroid hormone levels following LSG for morbid obesity. TSH decrease and steady levels of FT4 are expected following LSG. These findings are comparable to reported changes following LRYGB. TSH decrease was not associated with EWL. Further studies are required to elucidate the exact mechanism of this effect.

The lymph node ratio is a valuable prognostic factor in node-positive colon cancer patients undergoing laparoscopic resection. Patients with an LNR below 0.13 have the same long-term outcome as stage II node-negative patients. The laparoscopic approach presents the same trends in terms of overall survival and disease-free survival as conventional open access when LNR is considered.

Perioperative blood transfusion is associated with decreased long-term survival in patients undergoing laparoscopic resection for colorectal cancer. However, this association apparently reflects the poorer medical condition of patients requiring surgery and not a causative relationship.