The Identification of B cell subsets with regulatory functions might open the way to new therapeutic strategies in the field of transplantation, which aim to reduce the dose of immunosuppressive drugs and prolong the graft survival. CD25 was proposed as a marker of a B-cell subset with an immunosuppressive action termed Bregs. The effect of CD19 + CD25 + Bregs on graft function in renal transplant recipients has not yet been elucidated. We investigated a potential impact of CD19 + CD25 + Bregs on renal graft function as well as a possible interaction of CD19 + CD25 + Bregs with peripheral Tregs in healthy controls, end-stage kidney disease patients (ESKD), and renal transplant recipients. Moreover, we aimed to investigate the association of CD19 + CD25 + Bregs with serum IL-10, TGF-ß1, and IFN-γ in the same study groups.

Objectives

Chronic kidney disease (CKD) patients are liable to changes in zinc homeostasis through anorexia and dietary restrictions, as well as hemodialysis (HD). Changes in zinc homeostasis might predispose CKD and HD patients to specific adverse effects, including erythropoietin-resistant anemia, oxidative stress, atherosclerosis, and cardiovascular disease. Since serum zinc levels are rarely measured in CKD and HD patients, zinc supplementations do not represent a routine therapy for CKD and dialysis patients. Therefore, in this meta-analysis, we aimed to assess serum zinc levels in CKD and HD patients compared with healthy controls (HC). In addition, we investigated whether HD affects serum zinc levels by comparing serum zinc levels in HD versus CKD patients and comparing serum zinc pre- versus post-HD.

Methods

A comprehensive search of databases was conducted to identify either observational studies or randomized trials that assessed serum zinc levels in either CKD and /or HD patients in comparison to HC. We conducted a random-effects meta-analysis.

Results

Our meta-analysis included 42 studies with a total of 4161 participants, of whom 460 represented CKD patients, whereas 2047 patients represented HD patients. 1654 participants were healthy controls. Both CKD and HD patients showed lower serum zinc levels compared with HC (mean difference = -22.86 μg/dl, 95% CI [-33.25, -12.46]; mean difference = -13.64 μg/dl, 95% CI [-21.47, -53.80], respectively). CKD and HD patients showed no significant difference in serum zinc levels (mean difference = 15.39, 95% CI [-8.91, 39.68]). Pre-HD serum zinc levels were significantly lower than those post-HD (mean difference = -7.51 μg/dl, 95% CI [-14.24, -0.78]).

Conclusion

Occurrence of Lower serum zinc levels in CKD and HD patients than in HC appears to be more frequent than reported in daily clinical practice. An increase in the frequency of zinc measurement might be beneficial.

Patients receiving maintenance dialysis (MD) are vulnerable to COVID-19-related morbidity and mortality. Currently, data on SARS-CoV-2-specific cellular and humoral immunity post-vaccination in this population are scarce.

We conducted a prospective single-center study exploring the specific cellular (interferon-γ and interleukin-2 ELISpot assays) and humoral immune responses (dot plot array and chemiluminescent microparticle immunoassay [CMIA]) at 4 weeks and 6 weeks following a single dose or a complete homologous dual dose SARS-CoV-2 vaccine regimen in 60 MD patients (six with a history of COVID-19).

Our results show that MD patients exhibit a high seroconversion rate (91.7%) but the anti-spike IgG antibodies (CMIA) tend to wane rapidly after full immunization. Only 51.7% of the patients developed T cell immune response. High anti-spike IgG antibodies may predict a better cellular immunity …