Hypertension is a major cardiovascular risk factor in both kidney transplant recipients (KTRs) and patients with chronic kidney disease (CKD). Ambulatory blood pressure monitoring (ABPM) is considered the gold-standard method for hypertension management in these subjects. This is the first study evaluating the full ambulatory blood pressure (BP) profile and short-term BP variability (BPV) in KTRs versus CKD patients without kidney replacement therapy. Methods: Ninety-three KTRs were matched with 93 CKD patients for age, sex, and estimated glomerular filtration rate. All participants underwent 24-hour ABPM. Mean ambulatory BP levels, BP trajectories, and BPV indices (standard deviation [SD], weighted SD, and average real variability) were compared between the two groups. Results: There were no significant between-group differences in 24-hour systolic BP (SBP)/diastolic BP (DBP) (KTRs: 126.9 ± 13.1/79.1 ± 7.9 mmHg vs. CKD: 128.1 ± 11.2/77.9 ± 8.1 mmHg, p = 0.52/0.29), daytime SBP/DBP and nighttime SBP; nighttime DBP was slightly higher in KTRs (KTRs: 76.5 ± 8.8 mmHg vs. CKD: 73.8 ± 8.8 mmHg, p = 0.04). Repeated measurements analysis of variance showed a significant effect of time on both ambulatory SBP and DBP (SBP: F = [19, 3002] = 11.735, p < 0.001, partial η2 = 0.069) but not of KTR/CKD status (SBP: F = [1, 158] = 0.668, p = 0.42, partial η2 = 0.004). Ambulatory systolic/diastolic BPV indices were not different between KTRs and CKD patients, except for 24-hour DBP SD that was slightly higher in the latter group (KTRs: 10.2 ± 2.2 mmHg vs. CKD: 10.9 ± 2.6 mmHg, p = 0.04). No differences were noted in dipping pattern between the two groups. Conclusion: Mean ambulatory BP levels, BP trajectories, and short-term BPV indices are not significantly different between KTRs and CKD patients, suggesting that KTRs have a similar ambulatory BP profile compared to CKD patients without kidney replacement therapy.

Background: The response to vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) varies depending on comorbidities. This study evaluated the clinical and immunological factors affecting the humoral response of patients with end-stage renal disease (ESRD) to the BNT162b2 vaccine. Methods: Humoral immunity was evaluated in 54 ESRD patients using serum levels of anti-receptor-binding domain (RBD) and neutralizing antibodies (NAbs), measured by a chemiluminescent immunoassay 30 (T1), 60 (T2), and 120 (T3) days after the second vaccine dose. The results were correlated to baseline patient T- and B-lymphocyte subpopulations determined by flow cytometry. Results: The proportion of seroconverted patients based on the NAb titer decreased from 83.3% at Τ1 to 53.7% at Τ3. Age was negatively correlated to the NAb titer at T1 and Τ2. Patients receiving hemodiafiltration had higher NAb titers at T3. Diabetes was associated with a lower response rate at T3. Univariate analysis revealed a positive correlation between the naïve CD4 T-lymphocyte population and RBD titer at T1 and the NAb titer at T3, with no association observed with naïve CD8 T lymphocytes. NAb titers at T3 were significantly correlated with late-differentiated CD4 T lymphocytes and terminally differentiated effector memory cells re-expressing CD45RA (TEMRA) CD8 T lymphocytes. RBD levels were positively correlated with naïve and memory B-lymphocyte counts at T3. Conclusions Age, diabetes, and hemodialysis prescription had significant impacts on the response to vaccination. T- and B-lymphocyte phenotypes are major determinants of the humoral response potency to SARS-CoV-2 vaccination with BNT162b2 in patients with ESRD.