Cellular and humoral immune responses to COVID-19 booster vaccination in Japanese dialysis patients.

BACKGROUND: Dialysis patients are susceptible to developing severe coronavirus disease 2019 (COVID-19) due to hypoimmunity. Antibody titers against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) after the primary vaccinations are lower in hemodialysis (HD) patients than in healthy individuals. This study aimed to evaluate the effect of a SARS-CoV-2 booster vaccination in HD and peritoneal dialysis (PD) patients based on antibody titers and cellular and humoral immunity. METHODS: Participants of the control, HD, and PD groups were recruited from 12 facilities. SARS-CoV-2 antigen-specific cytokine and IgG-antibody levels were measured. Regulatory T cells and memory B cells were counted using flow cytometry at 6 months after primary vaccination with BNT162b2 and 3 weeks after the booster vaccination in HD and PD patients and compared with those of a control group. RESULTS: Booster vaccination significantly enhanced the levels of antibodies, cytokines, and memory B cells in three groups. The HD group showed significantly higher levels of IgG-antibodies, IL-1ß, IL-2, IL-4, IL-17, and memory B cells than those in the control group at 3 weeks after the booster dose. The PD group tended to show similar trends to HD patients but had similar levels of IgG-antibodies, cytokines, and memory B cells to the control group. CONCLUSIONS: HD patients had significantly stronger cellular and humoral immune responses than the control 3 weeks after the booster dose. Our findings will help in developing better COVID-19 vaccination strategies for HD and PD patients.

A Dipeptidyl Peptidase-4 Inhibitor, Teneligliptin, Decreases Plasma Triglyceride-Rich Lipoprotein Remnants in Diabetic Patients with Chronic Kidney Disease Undergoing Hemodialysis.

OBJECTIVE: A high plasma level of remnant-like particle cholesterol (RLP-C), which is equivalent to triglyceride-rich lipoprotein remnant, is an important coronary risk marker. RLP-C level is high, independent of other plasma lipids, in patients with chronic kidney disease (CKD) undergoing hemodialysis. The effect of teneligliptin, a dipeptidyl peptidase (DPP)-4 inhibitor, on plasma levels of RLP-C in patients with diabetes mellitus and CKD under hemodialysis was studied. METHODS: Teneligliptin 20 mg/day was administered to 15 patients with diabetes and CKD undergoing hemodialysis for 12 weeks. Ten patients with diabetes and CKD undergoing hemodialysis were allocated to the control group. Blood was sampled following a 12-h fast. Fasting plasma glucose (FPG), C-peptide, triglyceride, low-density lipoprotein (LDL)-cholesterol (C), high-density lipoprotein (HDL)-C, RLP-C, apolipoprotein (apo) B, oxidized LDL, lipoprotein lipase, and glycated hemoglobin (HbA1c) were measured. RESULTS: HbA1c decreased in the teneligliptin group but significantly increased in the control group. FPG and RLP-C significantly decreased in the teneligliptin group. Plasma lipoprotein-related parameters except RLP-C were not affected by teneligliptin treatment. CONCLUSION: Teneligliptin treatment significantly reduced plasma levels of RLP-C, FPG, and HbA1c in patients with diabetes with CKD who are undergoing hemodialysis.

Low doses of losartan and trandolapril improve arterial stiffness in hemodialysis patients.

BACKGROUND: Hemodialysis patients have uremic dyslipidemia, represented by elevated serum intermediate-density lipoprotein cholesterol (IDL-C) levels, and an increased cardiovascular mortality rate. This study was performed to determine the low-dose effects of the angiotensin II receptor blocker losartan and the angiotensin-converting enzyme inhibitor trandolapril on pulse wave velocity (PWV), which predicts cardiovascular morbidity and mortality in hemodialysis patients. METHODS: Serum lipid levels and PWV were monitored for 12 months in 64 hemodialysis patients who were administered low doses of losartan or trandolapril or a placebo. RESULTS: At the start of the study, there were no differences in patient characteristics among the 3 groups. PWV tended to increase in the placebo group during the 12-month study period, but decreased significantly in the losartan and trandolapril groups, and decreases in PWV were similar in the losartan and trandolapril groups. There were no changes in blood pressure, hematocrit, erythropoietin dose, ankle-brachial index, serum lipid levels, serum 8-isoprostane levels, or serum C-reactive protein levels during the 12-month study period, but there was an increase in serum triglyceride levels in the losartan group and a decrease in serum IDL-C levels in the losartan and trandolapril groups. CONCLUSION: In hemodialysis patients, trandolapril is as effective as losartan in decreasing PWV independent of its depressor effect and in suppressing elevated IDL-C levels. Long-term blockade of the renin-angiotensin system may have a beneficial effect on the acceleration of atherosclerosis and uremic dyslipidemia.

Comparison of the effects of calcitriol and maxacalcitol on secondary hyperparathyroidism in patients on chronic haemodialysis: a randomized prospective multicentre trial.

BACKGROUND: To identify differences between the effects of calcitriol and the calcitriol analogue, maxacalcitol, on parathyroid hormone (PTH) and bone metabolisms, we conducted a randomized prospective multicentre study on patients on chronic haemodialysis. METHODS: We randomly assigned 91 patients with secondary hyperparathyroidism [intact PTH (iPTH) > or =150 pg/ml] to have either calcitriol (47 patients) or maxacalcitol (44 patients) therapy, for 12 months after a 1 month control period. Serum electrolytes, bone alkaline phosphatase (bAP), iPTH, total PTH and PTH(1-84) (whole PTH) levels were measured periodically. The first end point was a serum iPTH of <150 pg/ml, the second was the iPTH levels obtained. RESULTS: Treatment was discontinued for various reasons in nine patients in each group, but no serious side effects were observed in either group. The numbers of cases reaching the first end point were not significantly different between the two groups. Serum calcium concentration was significantly higher in the maxacalcitol than the calcitriol group during early treatment, but not at the end of treatment. Throughout the treatment period there were no significant differences between the two groups in serum iPTH, inorganic phosphate, the product of the serum calcium and inorganic phosphorus concentrations, bAP, or the ratio of whole PTH to total PTH minus whole PTH. Nor were the changes in these parameters significantly different between the two groups comparing the patients with moderate to severe hyperparathyroidism (basal iPTH > or =500 pg/ml). CONCLUSION: Calcitriol and maxacalcitol are equally effective on PTH and bone metabolism.