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 multi-institutional, observational study of outcomes after catheter placement for peritoneal dialysis in Japan.

BACKGROUND: This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications. METHODS: Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest. RESULTS: Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27-0.70) and straight type catheter (HR 2.14; 95% CI 1.24-3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30-5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines. CONCLUSION: PD catheter placement in Japan was proven to be safe and appropriate.

Comparing the efficacy of continuous erythropoietin receptor activator and darbepoetin Alfa treatments in Japanese patients with chronic kidney disease during the predialysis period: A propensity-matched analysis.

AIM: Erythropoiesis-stimulating agent (ESA) treatment during the predialysis period can be a strategy to reduce cardiac mortality soon after initiation of dialysis. In this study, we compared the efficacy of continuous erythropoietin receptor activator (CERA) and darbepoetin alfa (DA) in patients with chronic kidney disease (CKD) over 6 months prior to initiation of dialysis. METHODS: This study was a retrospective propensity score-matched study conducted at a single center in Japan that analyzed the effects of CERA and DA therapy on haemoglobin (Hb) changes, ESA resistance index (ERI) changes, and interval of ESA administration during a 6-month observation period prior to initiation of dialysis. Propensity scores were used for matching the patients included in the CERA and DA groups. RESULTS: Among 680 screened, 74 pairs of patients (one in each group) were included in the present analysis after propensity score matching. Mean Hb significantly decreased over 6 months in the DA group compared to that in the CERA group (-0.70 ± 0.23 vs. -0.33 ± 0.22). In the DA group, mean ERI was significantly increased at 4, 3, 2, and 1 month before dialysis and initiation of dialysis, while in the CERA group, mean ERI was significantly increased only at 1 month before dialysis and initiation of dialysis. Moreover, patients administered CERA were required to visit the hospital significantly less frequently for ESA administration than those administered DA. CONCLUSION: Our study showed that CERA may be more effective than DA for management of anaemia during the predialysis period in CKD patients.