T-Cell Response and Antibody Production Induced by the COVID-19 Booster Vaccine in Japanese Chronic Kidney Disease Patients Treated with Hemodialysis.

Humoral and cellular responses are critical in understanding immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. Here, we evaluated these responses in hemodialysis (HD) patients after the booster vaccination. SARS-CoV-2 immunoglobulin (IgG) levels, neutralizing antibody titers, and the T-SPOT®.COVID test (T-SPOT) were measured prior to, three weeks after, and three months after the booster administration. The HD group had significantly higher SARS-CoV-2 IgG levels and neutralizing antibody titers against the original strain at three weeks and three months after the booster vaccination compared to the control group, albeit the HD group had lower SARS-CoV-2 IgG levels and neutralizing antibody titers before the booster administration. Moreover, the HD group had significantly higher T-SPOT levels at all three time points compared to the control group. The HD group also had significantly higher local and systemic adverse reaction rates than the control group. By booster vaccination, HD patients could acquire more effective SARS-CoV-2-specific humoral and cellular immunity than the control group.

Effectiveness of SARS-CoV-2 vaccines on hemodialysis patients in Japan: A nationwide cohort study.

INTRODUCTION: This study compared the outcomes of dialysis patients who received SARS-CoV-2 vaccine with those who did not use data from the Japanese COVID-19 registry. METHODS: A total of 1260 dialysis patients with confirmed positive SARS-CoV-2 infection was included in this study. Patients were divided into two groups: patients who experienced breakthrough infection and those who were unvaccinated. The need of oxygen supplementation and mortality risks were compared using multivariate logistic regression analysis. RESULTS: The mortality rate was 24.2% in unvaccinated patients and 8.6% in breakthrough patients. The odds ratio of need of oxygen supplementation in the breakthrough patients relative to unvaccinated patients was 0.197. The hazard ratio of mortality in the breakthrough patients relative to unvaccinated patients was 0.464. CONCLUSION: Our prospective observational study showed that SRAS-CoV-2 vaccination in hemodialysis patients is vital for reducing need of oxygen supplementation and mortality risk.

The Impact and Treatment of COVID-19 in Hemodialysis Patients.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) undergoing maintenance hemodialysis have a poor prognosis and limited treatment options. METHODS: This paper outlines the impact of COVID-19, its treatment, and the efficacy of vaccines in Japanese patients undergoing hemodialysis with a review of the literature. RESULTS: Patients undergoing dialysis in dialysis facilities are at greater risk of exposure to severe acute respiratory syndrome coronavirus 2 than the general population due to limited isolation capabilities. Therefore, vaccines are expected to be effective for patients undergoing dialysis. In addition, effective use of available medications is important because treatment options are limited. CONCLUSIONS: Efforts should be made to prevent the spread of the infection to high-risk patients undergoing dialysis while ensuring the effective use of vaccines.

Implementation of two novel schemes for patients on dialysis as a response to the COVID-19 surge in Tokyo.

The Japanese government recommended hospitalization of patients on dialysis once they tested positive because of their high COVID-19 mortality rate and definite need for periodic dialysis. However, after experiencing the Delta variant surge, strategic changes towards outpatient care for mild or asymptomatic cases, along with strengthening emergency preparedness were needed. Facing the Omicron surge, the Tokyo Metropolitan Government introduced two novel schemes: i) a temporary medical facility with a dialysis center for infected patients on hemodialysis, which started admitting patients on dialysis on January 20, 2022, to provide additional bed capacity and access to hemodialysis and ii) a transportation scheme for patients who need travel to maintenance dialysis facilities from their homes, which was introduced on February 5. The Tokyo Metropolitan Government, cooperating with some nephrology experts, announced these schemes and urged local dialysis facilities to change strategies, providing information regarding infection prevention measures and treatments in online seminars on February 3 and 7. Consequently, promoting outpatient care did not lead to an increase in the case fatality ratio (CFR) in patients on dialysis with COVID-19 in Tokyo during the first Omicron surge (January 7 to February 10, 8.2%; February 11 to March 31, 5.5%). Furthermore, after an additional online seminar on July 20, the CFR dramatically declined in the second Omicron surge (July 8 to September 8, 1.2%). Implementation of public health intervention and careful communication with local dialysis facilities were both crucial to the strategic changes. To maintain essential health services, emergency preparedness should be cultivated during regular times.

新型コロナウイルスと血液透析

2019 年に中国湖北省武漢市から発生したと推定される新型コロナウイルス感染症（coronavirus disease 2019： COVID‒19）は急速に世界中に蔓延し，世界保 健機関は 2020 年 3 月 11 日にパンデミックに該当すると宣言した．国内では，2020 年 1 月 15 日に武漢市に 渡航歴のある肺炎患者から新型コロナウイルス（severe acute respiratory syndrome coronavirus 2： SARS‒CoV‒2）を検出，その後，第 1 波から第 5 波までの急 激な新規患者数の増加を経験した

Investigation for the efficacy of COVID-19 vaccine in Japanese CKD patients treated with hemodialysis

Background Dialysis patients are predisposed to severe disease and have a high mortality rate in coronavirus disease 2019 (COVID-19) due to their comorbidities and immunocompromised conditions. Therefore, dialysis patients should be prioritized for vaccination. This study aimed to examine how long the effects of the vaccine are maintained and what factors affect antibody titers. Methods Hemodialysis patients (HD group) and age- and sex-matched non-dialysis individuals (Control group), receiving two doses of BNT162b2 vaccine, were recruited through the Japanese Society for Dialysis Therapy (JSDT) Web site in July 2021. Anti-SARS-CoV-2 immunoglobulin (IgG) (SARS-CoV-2 IgG titers) was measured before vaccination, 3 weeks after the first vaccination, 2 weeks after the second vaccination, and 3 months after the second vaccination, and was compared between Control group and HD group. Factors affecting SARS-CoV-2 IgG titers were also examined using multivariable regression analysis and stepwise regression analysis (least AIC). In addition, we compared adverse reactions in Control and HD groups and examined the relationship between adverse reactions and SARS-CoV-2 IgG titers. Results Our study enrolled 123 participants in the Control group (62.6% men, median age 67.0 years) and 206 patients in the HD group (64.1% men, median age 66.4 years). HD group had significantly lower SARS-CoV-2 IgG titers at 3 weeks after the first vaccination (p < 0.0001), 2 weeks after second vaccination (p = 0.0002), and 3 months after the second vaccination (p = 0.045) than Control group. However, the reduction rate of SARS-CoV-2 IgG titers between 2 weeks and 3 months after the second vaccination was significantly smaller in HD group than in Control (p = 0.048). Stepwise regression analysis revealed that dialysis time was identified as the significant independent factors for SARS-CoV-2 IgG titers at 2 weeks after the second vaccination in HD group (p = 0.002) and longer dialysis time resulted in higher maximum antibody titers. The incidences of fever and nausea after the second vaccination were significantly higher in the HD group (p = 0.039 and p = 0.020). Antibody titers in those with fever were significantly higher than those without fever in both groups (HD: p = 0.0383, Control: p = 0.0096). Conclusion HD patients had significantly lower antibody titers than age- and sex-matched non-dialysis individuals over 3 months after vaccination. Dialysis time was identified as a factor affecting SARS-CoV-2 IgG titers in HD group, with longer dialysis time resulting in higher maximum SARS-CoV-2 IgG titers.

A case of COVID-19 reinfection in a hemodialysis patient: the role of antibody in SARS-CoV-2 infection.

Hemodialysis patients are vulnerable to severe and lethal COVID-19, and their protective immunity against COVID-19 is not yet fully understood. Therefore, we report a case of COVID-19 reinfection in a hemodialysis patient 81 days after the first episode and discuss the role of antibodies in SARS-CoV-2 infection. A hemodialysis patient developed asymptomatic COVID-19 due to an outbreak in a hospital on October 29th, 2020. As he was hospitalized and did not develop any symptoms, he was discharged on November 9th. On January 18th, he presented with symptomatic COVID-19 due to close household contact. Then, he developed respiratory failure and was transferred to National Center for Global Health and Medicine if he would need intensive care. He recovered with oxygen inhalation, favipiravir, and steroid treatment, and was discharged on February 12th. To evaluate anti-SARS-CoV-2 antibodies during two hospital stays, we measured immunoglobulin (Ig) G specific for S1 subunit of Spike (S) protein of SARS-CoV-2 (IgG-S1) , IgG specific for the full-length S protein (anti-Spike IgG) and neutralizing antibodies. No seroconversion occurred 5 days after initial infection, the seroconversion of IgG-S1 was observed 10 days after the second infection. Similar to IgG-S1 antibody titer results, anti-Spike IgG and neutralizing antibodies increased from 12 days after the second infection. In conclusion, we experienced a case of COVID-19 reinfection in a hemodialysis patient 81 days after the first episode and showed the kinetics and role of antibodies in SARS-CoV-2 infection. Further studies are needed to understand SARS-CoV-2 reinfection risk in hemodialysis patients and its clinical significance.

Survival and predictive factors in dialysis patients with COVID-19 in Japan: a nationwide cohort study.

BACKGROUND: The Japanese Association of Dialysis Physicians, the Japanese Society for Dialysis Therapy, and the Japanese Society of Nephrology jointly established COVID-19 Task Force Committee and began surveying the number of newly infected patients. METHODS: This registry of the COVID-19 Task Force Committee was used to collect data of dialysis patients; a total of 1010 dialysis patients with COVID-19 were included in the analysis. Overall survival of patients was investigated with stratification by age group, complication status, and treatment. In addition, predictive factors for mortality were also investigated. The overall survival was estimated by Kaplan-Meier methods and compared by using log-rank test. Multivariate analysis was performed to identify the risk factor of mortality. For all statistical analyses, p < 0.05 was considered to be statistically significant. RESULTS: The mortality risk was increased with age (p < 0.001). The mortality risk was significantly higher in patients with peripheral arterial disease (HR: 1.49, 95% CI 1.05-2.10) and significantly lower in patients who were treated with remdesivir (HR: 0.60, 95% CI 0.37-0.98). Multivariate analysis showed increased risk of mortality with increment in BMI, and increment in CRP, and decreased risk with increment in albumin. CONCLUSION: Dialysis patients have a high severity of illness and a high risk of mortality in cases of COVID-19. Treatment with remdesivir might be effective in shortening the duration of hospitalization and reducing the risk of mortality.

Committee report: Questionnaire survey on the treatment of COVID-19 in patients receiving dialysis therapy.

Background: Patients with coronavirus disease 2019 (COVID-19) who receive dialysis therapy develop more severe disease and have a poorer prognosis than patients who do not. Although various data on the treatment of patients not receiving dialysis therapy have been reported, clinical practice for patients on dialysis is challenging as data is limited. The Infection Control Committee of the Japanese Society for Dialysis Therapy decided to clarify the status of treatment in COVID-19 patients on dialysis. Methods: A questionnaire survey of 105 centers that had treated at least five COVID-19 patients on dialysis was conducted in August 2021. Results: Sixty-six centers (62.9%) responded to the questionnaire. Antivirals were administered in 27.7% of facilities treating mild disease (most patients received favipiravir) and 66.7% of facilities treating moderate disease (most patients with moderate or more severe conditions received remdesivir). Whether and how remdesivir is administered varies between centers. Steroids were initiated most frequently in moderate II disease (50.8%), while 43.1% of the facilities initiated steroids in mild or moderate I disease. The type of steroid, dose, and the duration of administration were generally consistent, with most facilities administering dexamethasone 6 mg orally or 6.6 mg intravenously for 10 days. Steroid pulse therapy was administered in 48.5% of the facilities, and tocilizumab was administered in 25.8% of the facilities, mainly to patients on ventilators or equivalent medications, or to the cases of exacerbations. Furthermore, some facilities used a polymethylmethacrylate membrane during dialysis, nafamostat as an anticoagulant, and continuous hemodiafiltration in severe cases. There was limited experience of polymyxin B-immobilized fiber column-direct hemoperfusion and extracorporeal membrane oxygenation. The discharge criteria for patients receiving dialysis therapy were longer than those set by the Ministry of Health, Labor and Welfare in 22.7% of the facilities. Conclusions: Our survey revealed a variety of treatment practices in each facility. Further evidence and innovations are required to improve the prognosis of patients with COVID-19 receiving dialysis therapy.

Factors associated with SARS-CoV-2 antibody titers and prognosis of breakthrough infection in hemodialysis patients.

BACKGROUND: The mortality rate of Coronavirus disease 2019 (COVID-19) is extremely high in hemodialysis patients (HDP). These patients also develop lower antibody titers after vaccination. Therefore, factors associated with antibody titers and vaccine efficacy in HDP with breakthrough infection need to be investigated. METHODS: We measured anti-S1 antibody titers in HDP (n = 104) and controls (n = 35), evaluating the influence of background on HDP by multivariable regression analysis. We classified 26 HDP patients admitted with COVID-19 into the unvaccinated (n = 15) and breakthrough infection group (n = 11), performing between-group comparisons of laboratory findings and prognosis. Vaccinated COVID-19 patients were classified into HDP and non-HDP controls, and compared the relationship between antibody titer and severity, and the prognosis of breakthrough infection. RESULTS: The antibody titer was significantly lower in the HDP group than in the control group. Among HDP, age and smoking history were significantly independent factors associated with antibody titer. The breakthrough infection group had significantly better laboratory findings (KL-6 and LDH), severity, and hospitalization period than the unvaccinated group even if antibody titers were lower than the known threshold for neutralization (p < 0.05). There was no significant difference in prognosis between the HDP and non-HDP with breakthrough infection. Severity of COVID-19 tended to be higher with lower antibody titer in non-HDP, but not in HDP. CONCLUSION: Vaccines improved the severity of COVID-19 and hospitalization period of breakthrough infection in HDP, although HDP, especially in elderly smokers had lower antibody titers than control. There was no significant association between antibody titer and severity in HDP.

Nationwide survey of the coronavirus disease 2019 prevention and treatment systems for kidney disease patients: a study of Japanese Society of Nephrology-certified educational facilities.

BACKGROUND: There are no reports of a large-scale survey on the infection prevention measures against coronavirus disease 2019 (COVID-19) in nephrology facilities. This study investigated the facility-level nephrology practices adopted during the COVID-19 pandemic and their associated challenges. Additionally, the treatment patterns and outcomes of chronic kidney disease (CKD) patients with COVID-19 were reviewed. METHODS: We conducted a nationwide questionnaire survey of 704 educational facilities that were certified by the Japanese Society of Nephrology (JSN) from October 20, 2020 to November 16, 2020. The questionnaire reviewed the facility characteristics, infection prevention measures taken during routine nephrology practice, impact of COVID-19 on nephrology practice, experiences in managing CKD patients with COVID-19, and nosocomial transmission in the nephrology unit. RESULTS: Of the 347 facilities that responded, 95.1% checked outpatients' body temperatures and COVID-19 symptoms at their visits. To reduce face-to-face contact, 80% and 70% of the facilities lengthened the intervals between outpatient visits and introduced online/telephonic consultations, respectively. As a result, more than half of the hospitals experienced a decrease in the numbers of outpatients and inpatients (64% and 50%, respectively). During the study period, 347 facilities managed 479 CKD patients with COVID-19. Oxygen administration and mechanical ventilation were performed for 47.8% and 16.5% of the patients, respectively, with a 9.2% total mortality rate. CONCLUSION: This survey demonstrated that JSN-certified educational nephrology facilities adopted multiple measures to manage the COVID-19 pandemic; however, they faced several challenges. Sharing these experiences could standardize these approaches and prepare us better for the future.

Infection prevention measures for patients undergoing hemodialysis during the COVID-19 pandemic in Japan: a nationwide questionnaire survey.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic affecting a variety of medical treatments, including hemodialysis. This study aims to investigate the implementation of infection control measures, to examine the shortage of personal protective equipment (PPE) and disinfectants, and to quantify the number of nosocomial COVID-19 transmissions in hemodialysis facilities in Japan during the pandemic. METHODS: We conducted a nationwide questionnaire survey between 20 October and 16 November 2020 (i.e., between the "second wave" and "third wave" in Japan) in the 4198 dialysis facilities of the Japanese Association of Dialysis Physicians and the Japanese Society for Dialysis Therapy. A total of 2227 facilities (53.0%) responded. The questionnaire consisted of (i) characteristics of facilities, (ii) infection prevention measures in routine dialysis practices, (iii) shortage of PPE, (iv) feasibility of various isolation measures, and (v) nosocomial transmission. RESULTS: Half of the responding facilities were hospitals with multiple departments, and the other half were clinics specialized in dialysis. Several infection prevention measures such as health checks of staff and patients, donning of masks before and after hemodialysis, and disinfection of frequently contacted areas were implemented during the COVID-19 pandemic. There was a significant improvement in the implementation rate of these measures during the pandemic, compared to before it, which reached over 90%. More than half of the facilities reported a shortage of disposable masks (67.2%) and hand sanitizer alcohol (56.7%). Isolation of COVID-19 patients in private rooms was possible only in 52.7% of the facilities. The majority of facilities (73.3%) could not accept COVID-19 dialysis patients due to lack of space and manpower. Nosocomial transmission of COVID-19 occurred in 4.0% of the facilities. Of those infected, 51.9% were staff. CONCLUSIONS: This survey revealed that most hemodialysis facilities in Japan had improved implementation of infection control measures and had shortage of PPEs and disinfectants, though some facilities did not implement infection prevention measures adequately, mainly due to the limited space of the facility. It may be recommended that each facility immediately establishes isolation measures to prepare for the pandemic of COVID-19. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s41100-021-00350-y.

COVID-19 of dialysis patients in Japan: Current status and guidance on preventive measures.

In Japan, the first case of COVID-19 in dialysis patients was reported on March 1, 2020. A total of 31 cases were reported by April 10, and it increased to 95 by May 15. Thereafter, with the rapid increase in the number of COVID-19 cases in the general population since late March, there was a not surprising increase in the number of COVID-19 cases in dialysis patients. The mortality rate is 16.2% (16/99 cases) in dialysis patients, which is higher than 5.3% (874/16 532 cases) in the general population. This higher mortality rate in dialysis patients with COVID-19 might be related to their age; the majority of COVID-19 cases are aged between 70 and 90 years old in dialysis patients, compared with between 20 and 60 years old in the general population. As COVID-19 presents with severe symptoms and is associated with a high mortality rate in dialysis patients, dialysis patients who have contracted severe acute respiratory syndrome coronavirus 2 infection confirmed by polymerase chain reaction testing are required to be hospitalized under Japanese government policy. In cases of COVID-19 hospitalizations, it is essential to prevent nosocomial infection. Therefore, patients must be sufficiently instructed in infection prevention and robust measures to prevent contraction and spread of the infection must be taken at dialysis facilities.