Impaired Immune Response to SARS-CoV-2 Vaccination in Dialysis Patients and in Kidney Transplant Recipients

Predicting immunogenicity of COVID-19 vaccines in hemodialysis patients with renal disease

Individuals who are diagnosed with chronic kidney disease, particularly those receiving maintenance hemodialysis treatment, face a greater likelihood of suffering from severe symptoms and fatality due to COVID-19. This study aimed to explore the optimal vaccination approach for these individuals. The study used data analysis tasks such as data preprocessing, cleaning, and exploration, and machine learning models including linear regression, random forest, XGBoost, gradient boosting, AdaBoost, decision trees, Lasso, and ridge regression were used to construct the predictive model. The study found that the Lasso model performed the best overall in predicting anti-S IgG antibodies levels in response to COVID-19 vaccines for people with kidney failure with MAE of 8.81, RMSE of 19.59, and R2 value of 0.93. The adjusted R2 value for the Lasso model was also 0.93, indicating that the model's ability to explain the variance in the data was not affected by the number of predictors in the model. The Random Forest model best predicted the duration of immunogenicity, with R2 and adjusted R2 values of 0.71 and 0.69, respectively. The ensemble model that includes all eight models, i.e., Ridge, Lasso, Linear Regression, Random Forest, AdaBoost, Gradient Boosting, XGBoost, and Decision Tree, has the best performance with the lowest MAE, the lowest RMSE, the highest R2, and the highest adjusted R2 values of 3.91, 5.00, 0.73, and 0.72, respectively. However, further research is required to validate these models and extend their application to different populations and vaccine types, as well as considering other factors that may affect immune response to COVID-19 vaccines. These findings can be helpful in improving vaccination strategies and promoting public health.

Low switched memory B cells are associated with no humoral response after SARS-CoV-2 vaccine boosters in kidney transplant recipients

Introduction

The humoral response after SARS-CoV-2 vaccination and boosters in kidney transplant recipients (KTRs) is heterogeneous and depends on immunosuppression status. There is no validated immune measurement associated with serological response in clinical practice. Multicolor flow cytometric immunophenotyping could be useful for measuring immune response. This study aimed to study B- and T-cell compartments through Standardized EuroFlow PID Orientation after SARS-CoV-2 vaccination and their association with IgG SARS-CoV-2 seropositivity status after two doses or boosters.

Methods

We conducted a multicenter prospective study to evaluate humoral response after SARS-CoV-2 vaccination in KTRs. Heterologous regimen: two doses of inactivated SARS-CoV-2 and two boosters of BNT162b2 mRNA (n=75). Homologous vaccination: two doses of BNT162b2 mRNA and one BNT162b2 mRNA booster (n=13). Booster doses were administrated to KTRs without taking into account their IgG SARS-CoV-2 seropositivity status. Peripheral blood samples were collected 30 days after the second dose and after the last heterologous or homologous booster. A standardized EuroFlow PID Orientation Tube (PIDOT) and a supervised automated analysis were used for immune monitoring cellular subsets after boosters.

Results

A total of 88 KTRs were included and divided into three groups according to the time of the first detected IgG SARS-CoV-2 seropositivity: non-responders (NRs, n=23), booster responders (BRs, n=41), and two-dose responders (2DRs, n=24). The NR group was more frequent on mycophenolate than the responder groups (NRs, 96%; BRs, 80%; 2DRs, 42%; p=0.000). Switched memory B cells in the 2DR group were higher than those in the BR and NR groups (medians of 30, 17, and 10 cells/ul, respectively; p=0.017). Additionally, the absolute count of central memory/terminal memory CD8 T cells was higher in the 2DR group than in the BR and NR groups. (166, 98, and 93 cells/ul, respectively; p=0.041). The rest of the T-cell populations studied did not show a statistical difference.

Conclusion

switched memory B cells and memory CD8 T-cell populations in peripheral blood were associated with the magnitude of the humoral response after SARS-CoV-2 vaccination. Boosters increased IgG anti-SARS-CoV-2 levels, CM/TM CD8 T cells, and switched MBCs in patients with seropositivity after two doses. Interestingly, no seropositivity after boosters was associated with the use of mycophenolate and a lower number of switched MBCs and CM/TM CD8 T cells in peripheral blood.

Humoral response to SARS-CoV-2 mRNA vaccine on in ABO blood type incompatible kidney transplant recipients treated with low-dose rituximab

We aimed to evaluate the humoral response after the second and third doses of SARS-CoV-2 mRNA vaccine in ABO blood type incompatible kidney transplant (KT) recipients treated with rituximab. This retrospective study conducted between June 2021 and June 2022 included 131 KT recipients and 154 nontransplant controls who had received mRNA vaccines. We compared the seropositivity (anti-SARS-CoV-2 spike IgG antibody titer ≥ 0.8 U/mL) after the second and third vaccinations. Furthermore, we evaluated the impact of pretransplant vaccination for seropositivity. Of the 131 KT recipients, 50 had received the third dose of mRNA vaccine. The antibody titer was significantly increased after the third dose of mRNA vaccine. The seropositivity rate after the third dose of mRNA vaccine increased from 36 to 70%. We observed no significant difference in seropositivity after the third dose of mRNA vaccine in ABO incompatibility, rituximab use, mycophenolate mofetil use, and age at KT. Of the nine recipients who had received the second or third dose of the mRNA vaccine prior to the KT, eight of the recipients were seropositive both before and after the KT. Our results suggest that ABO incompatibility or rituximab use was not significantly associated with seropositivity.

COVID-19 vaccine in hemodialysis patients: Time for a boost

OBJECTIVES

To evaluate anti-spike immunoglobulin G (IgG) antibody levels of hemodialysis patients and correlate them with the patients' demographic data and to evaluate these patients' need for a coronavirus disease-19 (COVID-19) vaccine booster.

METHODS

A cross-sectional multi-center study carried out at King Abdulaziz Kidney Center, Hasan Tahir Hemodialysis Center, and Hayat Organization Hemodialysis Center in Al-Madinah Al-Munawarah, Saudi Arabia. Patients (n=167) who received a minimum single dose of COVID-19 vaccine were recruited. The samples were collected between March 2022 and January 2023. Anti-spike IgG antibody levels were measured using enzyme-linked immunosorbent assays.

RESULTS

A significantly higher proportion of patients who received 3 doses of COVID-19 vaccine had positive serostatus compared with patients who received one or 2 doses (3 doses: 87.2%, one dose: 0.0%, 2 doses: 77.3%; p=0.000). Compared with patients who received one dose, significantly higher IgG antibody levels were detected in patients who received 2 (p=0.013) and 3 doses (p=0.025; n=35). In contrast, there was no significant difference in IgG antibody levels between patients who received 2 or 3 doses (p=0.45). Significant IgG antibody levels were detected in patients who received 2 and 3 doses (p=0.0125) compared with those received one vaccine dose (p=0.0004). Furthermore, patients who received 3 doses had significantly higher IgG antibody levels than patients who received 2 doses (p=0.000).

CONCLUSION

The results show a dose-dependent association between IgG antibody levels and the number COVID-19 vaccines received. The study highlights the need for booster COVID-19 vaccination for patients on hemodialysis.

Immune Status and SARS-CoV-2 Viral Dynamics

Immunocompromised individuals are disproportionately affected by severe coronavirus disease 2019, but immune compromise is heterogenous, and viral dynamics may vary by the degree of immunosuppression. In this study, we categorized ACTIV-2/A5401 participants based on the extent of immunocompromise into none, mild, moderate, and severe immunocompromise. Moderate/severe immunocompromise was associated with higher nasal viral load at enrollment (adjusted difference in means: 0.47 95% confidence interval, .12-.83 log10 copies/mL) and showed a trend toward higher cumulative nasal RNA levels and plasma viremia compared to nonimmunocompromised individuals. Immunosuppression leads to greater viral shedding and altered severe acute respiratory syndrome coronavirus 2 viral decay kinetics. Clinical Trials Registration. NCT04518410.

Cellular immune response of SARS-CoV-2 vaccination in kidney transplant recipients: a systematic review and meta-analysis

Background

Evidence has demonstrated inferior humoral immune responses after SARS-CoV-2 vaccination in kidney transplant recipients compared to the general population. However, data on cellular immune responses in this population have not been established.

Methods

We searched the MEDLINE, Scopus, and Cochrane databases and included studies reporting cellular immune response rates in kidney transplant recipients after receiving SARS-CoV-2 vaccines. Studies that reported factors associated with cellular immune responders or non-responders were also included (PROSPERO: CRD42022375544).

Results

From a total of 1,494 articles searched, 53 articles were included in the meta-analysis. In all, 21 studies assessed cellular immune response by interferon-γ enzyme-linked immunosorbent spot (IFN-γ ELISPOT), 22 studies used interferon-γ release assay (IGRA), and 10 studies used flow cytometric analysis. The pooled response rate after two doses (standard regimen) and three doses of vaccination was 47.5% (95%CI 38.4-56.7%) and 69.1% (95%CI 56.3-80.6%) from IFN-γ ELISPOT, 25.8% (95%CI 19.7-32.4%) and 14.7% (95%CI 8.5-22.2%) from IGRA, and 73.7% (95%CI 55.2-88.8%) and 86.5% (95%CI 75.3-94.9%) from flow cytometry, respectively. Recipients with seroconversion were associated with a higher chance of having cellular immune response (OR 2.58; 95%CI 1.89-3.54). Cellular immune response in kidney transplant recipients was lower than in dialysis patients (OR 0.24; 95%CI 0.16-0.34) and the general population (OR 0.10; 95%CI 0.07-0.14). Age and immunosuppressants containing tacrolimus or corticosteroid were associated with inferior cellular immune response.

Conclusion

Cellular immune response after SARS-CoV-2 vaccination in kidney transplant recipients was lower than in dialysis patients and the general population. Age, tacrolimus, and corticosteroid were associated with poor response. Cellular immune response should also be prioritized in vaccination studies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022375544.

Immunogenicity and safety of inactivated SARS-CoV-2 vaccine in haemodialysis patients: a prospective cohort study

End-stage renal disease patients on haemodialysis (HD) have been largely excluded from SARS-CoV-2 vaccine trials due to safety reasons and shown to mount lower responses to vaccination. This study aims to evaluate the immunogenicity and safety of inactivated COVID-19 vaccine among HD patients compared to healthy controls. All subjects who received the primary inactivated COVID-19 vaccination had their blood samples tested 21 days after the second dose. We report the immunogenicity based on anti-RBD IgG titre (IU/mL), the inhibition rate of neutralizing antibodies (NAbs) (%) to RBD, and seroconversion rates. Adverse events were assessed within 30 min and on the 7th day after each dose. Among 75 HD patients and 71 healthy controls, we observed no significant difference in all immunogenicity measures: anti-RBD IgG GMT (277.91 ± 7.13 IU/mL vs. 315.50 ± 3.50 IU/mL, p = 0.645), NAbs inhibition rate (82% [53-96] vs. 84% [39-98], p = 0.654), and seroconversion rates (anti-RBD IgG: 86.7% vs. 85.9%, p = 0.895; NAbs: 45.3% vs. 60.6%, p = 0.065). The number of adverse events is not significantly different between the two groups. The primary inactivated SARS-CoV-2 vaccination elicits an adequate antibody response and can be safely administered in haemodialysis patients.

Differential cellular and humoral immune responses in immunocompromised individuals following multiple SARS-CoV-2 vaccinations

Introduction

The heterogeneity of the immunocompromised population means some individuals may exhibit variable, weak or reduced vaccine-induced immune responses, leaving them poorly protected from COVID-19 disease despite receiving multiple SARS-CoV-2 vaccinations. There is conflicting data on the immunogenicity elicited by multiple vaccinations in immunocompromised groups. The aim of this study was to measure both humoral and cellular vaccine-induced immunity in several immunocompromised cohorts and to compare them to immunocompetent controls.

Methods

Cytokine release in peptide-stimulated whole blood, and neutralising antibody and baseline SARS-CoV-2 spike-specific IgG levels in plasma were measured in rheumatology patients (n=29), renal transplant recipients (n=46), people living with HIV (PLWH) (n=27) and immunocompetent participants (n=64) post third or fourth vaccination from just one blood sample. Cytokines were measured by ELISA and multiplex array. Neutralising antibody levels in plasma were determined by a 50% neutralising antibody titre assay and SARS-CoV-2 spike specific IgG levels were quantified by ELISA.

Results

In infection negative donors, IFN-γ, IL-2 and neutralising antibody levels were significantly reduced in rheumatology patients (p=0.0014, p=0.0415, p=0.0319, respectively) and renal transplant recipients (p<0.0001, p=0.0005, p<0.0001, respectively) compared to immunocompetent controls, with IgG antibody responses similarly affected. Conversely, cellular and humoral immune responses were not impaired in PLWH, or between individuals from all groups with previous SARS-CoV-2 infections.

Discussion

These results suggest that specific subgroups within immunocompromised cohorts could benefit from distinct, personalised immunisation or treatment strategies. Identification of vaccine non-responders could be critical to protect those most at risk.

A Third Dose of SARS-CoV-2 mRNA Vaccine Improves Immune Response in Chronic Kidney Disease Patients

Chronic kidney disease (CKD) patients have an increased risk of morbidity and mortality following SARS-CoV-2 infection. Vaccination in these patients is prioritized, and monitoring of the immune response is paramount to define further vaccination strategies. This prospective study included a cohort of 100 adult CKD patients: 48 with kidney transplant (KT) and 52 on hemodialysis without prior COVID-19. The patients were assessed for humoral and cellular immune responses after four months of an anti-SARS-CoV-2 primary two-dose vaccination scheme (CoronaVac or BNT162b2) and one month after a booster third dose of BNT162b2 vaccine. We identified poor cellular and humoral immune responses in the CKD patients after a primary vaccination scheme, and these responses were improved by a booster. Robust polyfunctional CD4⁺ T cell responses were observed in the KT patients after a booster, and this could be attributed to a higher proportion of the patients having been vaccinated with homologous BNT162b2 schemes. However, even after the booster, the KT patients exhibited lower neutralizing antibodies, attributable to specific immunosuppressive treatments. Four patients suffered severe COVID-19 despite three-dose vaccination, and all had low polyfunctional T-cell responses, underscoring the importance of this functional subset in viral protection. In conclusion, a booster dose of SARS-CoV-2 mRNA vaccine in CKD patients improves the impaired humoral and cellular immune responses observed after a primary vaccination scheme.

Clinical manifestations of COVID-19 infection in dialysis patients and protective effect of COVID-19 vaccine

BACKGROUND AND OBJECTIVE

COVID-19 infection poses a special challenge to patients with dialysis patients. The purpose of this study was to evaluate the clinical manifestations of dialysis patients with COVID-19 and the protective effect of the vaccine.

METHODS

We included 41 studies based on big data, mainly analyzing the clinical symptoms of dialysis patients with COVID-19, the proportion of severe patients before and after vaccination, and the humoral reaction of vaccine in the body.

RESULTS

6.1% to 35.7% of dialysis patients with COVID-19 developed respiratory distress symptoms and needed to be admitted to an intensive care unit for mechanical ventilation. The incidence and mortality of COVID-19 in dialysis patients before vaccination were 5.5% and 1.1%, respectively, and decreased to 4.5% and 0.6% in breakthrough infected patients. There was no statistical difference in serum conversion rates between dialysis patients and healthy controls, but the neutralizing antibody titer in the control group was 1922 (IQR 533 to 3186) AU/mL, and the neutralizing antibody titer in dialysis patients significantly decreased to 367 (IQR 171 to 1650) AU/mL (P=0.046).

CONCLUSIONS

Dialysis is associated with an increased risk of severe COVID-19, and generally has a poor seroconversion response to vaccines. It also confirms the protective effect of vaccines on high-risk populations such as dialysis.

Human brain organoids to explore SARS-CoV-2-induced effects on the central nervous system

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). In less than three years, an estimated 600 million infections with SARS-CoV-2 occurred worldwide, resulting in a pandemic with tremendous impact especially on economic and health sectors. Initially considered a respiratory disease, COVID-19, along with its long-term sequelae (long-COVID) rather is a systemic disease. Neurological symptoms like dementia or encephalopathy were reported early during the pandemic as concomitants of the acute phase and as characteristics of long-COVID. An excessive inflammatory immune response is hypothesized to play a major role in this context. However, direct infection of neural cells may also contribute to the neurological aspects of (long)-COVID-19. To mainly explore such direct effects of SARS-CoV-2 on the central nervous system, human brain organoids provide a useful platform. Infecting these three-dimensional tissue cultures allows the study of viral neurotropism as well as of virus-induced effects on single cells or even the complex cellular network within the organoid. In this review, we summarize the experimental studies that used SARS-CoV-2-infected human brain organoids to unravel the complex nature of (long)-COVID-19-related neurological manifestations.

Outcomes of vaccinations against respiratory diseases in patients with end-stage renal disease undergoing hemodialysis: A systematic review and meta-analysis

Due to the nature of the disease, end-stage renal disease (ESRD) patients suffer from dysfunction of the adaptive immune system, which leads to a poorer response to vaccination. Accordingly, it is crucial to evaluate the efficacy and safety of management strategies, including vaccinations, which could potentially reduce the risk of respiratory diseases, such as pneumonia, influenza, or COVID-19, and its associated outcomes. We searched PubMed, CENTRAL, ScienceDirect, Scopus, ProQuest, and Google Scholar databases using designated MeSH keywords. The risk of bias was assessed using ROBINS-I. The quality of evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Relative risk (RR) and 95% confidence interval (CI) were calculated. Heterogeneity was investigated using forest plots and I2 statistics. This systematic review included a total of 48 studies, with 13 studies of influenza (H1N1 and H3N2) vaccination and 35 studies of COVID-19 vaccination. H1N1 vaccination in ESRD patients undergoing hemodialysis induced lower seroconversion rates (RR 0.62, 95% CI: 0.56-0.68, p <0.00001) and lower seroprotection rates (RR 0.76, 95% CI: 0.70-0.83, p <0.00001) compared to controls. H3N2 vaccination in ESRD patients undergoing hemodialysis yielded lower seroconversion rates (RR 0.76, 95% CI: 0.68-0.85, p <0.00001) and lower seroprotection rates (RR 0.84, 95% CI: 0.77-0.90, p <0.00001) compared to controls. Twenty-nine studies demonstrate significantly lower antibody levels in ESRD patients undergoing hemodialysis compared to the controls following COVID-19 vaccination. This review presents evidence of lower seroconversion and seroprotection rates after vaccination against viral respiratory diseases in patients with ESRD undergoing hemodialysis. Since hemodialysis patients are more susceptible to infection and severe disease progression, a weakened yet substantial serological response can be considered adequate to recommend vaccination against respiratory diseases in this population. Vaccination dose, schedule, or strategy adjustments should be considered in stable ESRD patients on maintenance hemodialysis. Trial registration: Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021255983, identifier: CRD42021255983.

Immunogenicity Rates after SARS-CoV-2 Three-Dose Vaccination in Patients under Dialysis: A Systematic Review and Meta-Analysis

BACKGROUND

Considering the indeterminate effects following the administration of three doses of the SARS-CoV-2 vaccine to patients under dialysis, the present study aimed to evaluate the immunogenicity rates of patients who received the three-dose vaccine.

METHODS

MEDLINE, Web of Science, EMBASE, ClinicalTrials.gov, and the Cochrane Central Register for Controlled Trials were searched to select the relevant literature to perform the present review. We included randomized controlled trials, non-randomized trials, prospective, observational cohort, and case-control studies to assess the humoral and cellular immune responses following the administration of the three-dose SARS-CoV-2 vaccine to patients receiving dialysis.

RESULTS

Overall, 38 studies are included in the meta-analysis presented in this paper. For patients on dialysis, the overall humoral antibody response rate is 97% following three doses of mRNA or viral vector vaccines and 100% following four doses of the SARS-CoV-2 vaccine. A subgroup analysis shows that the antibody response rate is 96% for patients on hemodialysis (HD) and 100% for those receiving peritoneal dialysis (PD). The antibody response rate in the different immunogen-vaccinated groups tends to be higher than that in the same immunogen-vaccinated group (99% vs. 96%). For those who exhibit no response following two doses of the vaccine, the third and fourth doses can elevate the antibody response rate to 81%, and that number for low responders increases to 96%. However, the pooled results obtained from the relatively few trials conducted indicate that the positive T-cell response rate only increases to 59% following three doses of the vaccine. The antibody response rate is not different between dialysis and non-dialysis groups (relative risk = 0.95, 95% CI 0.90-1.02) following three doses of the vaccine. The relative risks for a SARS-CoV-2 breakthrough infection, all-cause mortality, and hospital admissions are 0.59 (95% CI 0.30-1.04), 0.63 (95% CI 0.35-1.12), and 0.53 (95% CI 0.37-0.74), respectively, when comparing three doses with two doses of the vaccine administered to the dialysis population.

CONCLUSIONS

The third or fourth dose of the SARS-CoV-2 vaccine significantly increases the immunogenicity rates in dialysis patients, and this beneficial effect does not vary with the type of vaccine (the same or different immunogen vaccination), dialysis modality (HD or PD), or previous low response following the administration two doses of the vaccine. We believe that healthcare workers should encourage patients receiving dialysis to receive a third or fourth vaccine dose to strengthen their immunity against SARS-CoV-2.

Association of malnutrition with SARS-CoV-2 vaccine response in patients undergoing hemodialysis

BACKGROUND & AIMS

Patients undergoing dialysis are less likely to develop immune responses to SARS-CoV-2 vaccine. Malnutrition is common in the dialysis population. However, whether malnutrition contributes to the impaired immunogenicity remains unknown. The aim of this study was to assess the association between nutritional status and SARS-CoV-2 vaccine response in patients receiving maintenance hemodialysis.

METHODS

A total of 206 hemodialysis patients (mean age, 67 ± 13 years) without prior SARS-CoV-2 infection were examined for the primary outcome of seroconversion, defined as the detection of IgG antibodies (≥50 AU/mL) to the receptor-binding domain of the S1 spike protein of SARS-CoV-2 one month after a priming dose of ChAdOx1 nCoV-19, an adenovirus-vectored vaccine. Nutritional status was assessed by using the Controlling Nutritional Status (CONUT) score, an objective indicator of nutrition incorporating serum albumin, total cholesterol, and total lymphocyte count, as well as the subjective global assessment (SGA).

RESULTS

Overall, 16.5% of patients were classified as malnourished, and 64.1% of patients were at risk for malnutrition based on the CONUT score. Anti-SARS-CoV-2 IgG were the highest in patients with normal nutrition. In multivariate logistic regression analyses adjusted for age, sex, comorbidities, and use of immunosuppressants, patients with malnutrition remained less likely to develop an antibody response than those with normal nutrition (odds ratio 0.23, 95% CI, 0.07-0.76). SGA was a significant predictor of anti-SARS-CoV-2 IgG seroconversion in univariate but not multivariate analyses.

CONCLUSIONS

Malnutrition according to CONUT score is associated with impaired humoral responses to SARS-CoV-2 vaccination in patients undergoing hemodialysis. Our results highlight the importance of incorporating nutritional assessment into routine dialysis care to identify patients at risk for suboptimal immune responses after SARS-CoV-2 vaccination. Further research is needed to determine whether nutritional intervention can improve immune responses in these vulnerable patients.

Impact of ABO Compatibility/Incompatibility on the Perioperative Anti-SARS-CoV-2 Immunoglobulin G Levels in 2 Preoperatively Vaccinated Patients Undergoing Kidney Transplant: A Case Report

Herein, we monitored the perioperative anti-SARS-CoV-2 spike immunoglobulin G titers in patients who were preoperatively vaccinated with 2 doses of a COVID-19 messenger RNA vaccine. Additionally, we compared the clinical settings between ABO-incompatible and ABO-compatible pre-emptive kidney transplant (KTx). Case 1 was of a 45-year-old man who was an ABO-incompatible KTx recipient. Before transplant, his serum antibody titers decreased from 278 U/mL at baseline to 41.9 U/mL after desensitization therapy (84.9% lower) and 54.7 U/mL (80.3% lower) at day 8; it is now maintained at 4.1 U/mL at 6 months posttransplant (98.5% lower). Case 2 was of a 50-year-old man who was an ABO-compatible KTx recipient. His serum antibody titer level decreased from 786 U/mL at baseline to 386 U/mL on day 8 (50.8% lower) and is now maintained at 156 U/mL at 6 months posttransplant (80.1% lower). We suggest that anti-SARS-CoV-2 spike immunoglobulin G titers should be monitored during the perioperative period to determine the optimal timing of COVID-19 vaccine booster doses for the maintenance of protective immunity, particularly in ABO-incompatible KTx recipients who require desensitization therapy.

A systematic review assessing the effectiveness of COVID-19 mRNA vaccines in chronic kidney disease (CKD) individuals

Background: SARS-CoV-2 is a coronavirus that has rapidly spread across the world with a detrimental effect on the global population. Several reports have highlighted an increased mortality rate and a higher severity of COVID-19 infection in chronic kidney disease (CKD) individuals. Upon the development of various SARS-CoV-2 vaccines, mRNA vaccines including BNT162b2 and mRNA-1273 were deemed safe, with a high efficacy in preventing COVID-19 in the general population. This review investigates whether  SARS-CoV-2 mRNA vaccines are as effective in triggering an immune response in Dialysis Patients (DPs) and Kidney Transplant Recipients (KTRs) and if a third dose is required in this  population. Methods: A systematic search employing the PRISMA criteria was conducted in several major databases, with the data being extracted from publications for the period January 2021 to May 2022 (PROSPERO: CRD42022338514, June 15, 2022). Results: 80 studies were included in this analysis with a total cohort number of 15,059 participants. Overall, 85.29% (OR = 17.08, 95% CI = 15.84-18.42, I ² = 98%) and 41.06% (OR = 0.52, 95% CI = 0.48-0.5, I ² = 95%) of DPs and KTRs included in this review showed positive seroconversion after two doses of either mRNA vaccine, respectively. A total 76% (OR = 6.53, 95% CI = 5.63-7.5, I ² = 96%) of the cohort given a third dose of an mRNA vaccine demonstrated positive seroconversion, with 61.86% (OR = 2.31, 95% CI = 1.95-2.75 I ² = 95%) of the cohort that was assessed for a cellular response displaying a positive response. Conclusions: This data emphasises a reduced incidence of a positive immune response in DPs and KTRs compared to healthy controls, albeit a better response in DPs than when compared to KTRs alone was observed. A third dose  appears to increase the occurrence of an immune response in the overall DP/KTR cohort.

Development and validation of multivariable prediction models of serological response to SARS-CoV-2 vaccination in kidney transplant recipients

Repeated vaccination against SARS-CoV-2 increases serological response in kidney transplant recipients (KTR) with high interindividual variability. No decision support tool exists to predict SARS-CoV-2 vaccination response to third or fourth vaccination in KTR. We developed, internally and externally validated five different multivariable prediction models of serological response after the third and fourth vaccine dose against SARS-CoV-2 in previously seronegative, COVID-19-naïve KTR. Using 20 candidate predictor variables, we applied statistical and machine learning approaches including logistic regression (LR), least absolute shrinkage and selection operator (LASSO)-regularized LR, random forest, and gradient boosted regression trees. For development and internal validation, data from 590 vaccinations were used. External validation was performed in four independent, international validation cohorts comprising 191, 184, 254, and 323 vaccinations, respectively. LASSO-regularized LR performed on the whole development dataset yielded a 20- and 10-variable model, respectively. External validation showed AUC-ROC of 0.840, 0.741, 0.816, and 0.783 for the sparser 10-variable model, yielding an overall performance 0.812. A 10-variable LASSO-regularized LR model predicts vaccination response in KTR with good overall accuracy. Implemented as an online tool, it can guide decisions whether to modulate immunosuppressive therapy before additional active vaccination, or to perform passive immunization to improve protection against COVID-19 in previously seronegative, COVID-19-naïve KTR.

Immunogenicity of COVID-19 mRNA vaccines in hemodialysis patients: Systematic review and meta-analysis

Background and Aims

Vaccine response is a concern in hemodialysis patients. Given that hemodialysis patients were not included in clinical trials, we aimed to synthesize the available evidence on the immunogenicity of coronavirus disease 2019 (COVID‐19) mRNA vaccines in hemodialysis patients.

Methods

We searched Scopus, PubMed, Sciencedirect, and finally google scholar databases for studies on COVID‐19 mRNA‐vaccines immunogenicity in hemodialysis patients up to December 1, 2021. Eligible articles measured antibodies against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) spike or Receptor‐Binding Domain Antibody (S/RBD) postimmunization with COVID‐19 mRNA vaccines. The immunogenicity of the vaccine was evaluated using seroconversion rates measured between 21 and 30 days after the first immunization and between 14 and 36 days post the second dose. We included studies including participants without a history of COVID‐19 before vaccination. Healthy controls or health‐care workers served as the control groups. After selecting eligible articles, the data were finally extracted from included articles. We used a random effects model to estimate the pooled seroconversion rate after COVID‐19 mRNA vaccine administration. We assessed the heterogeneity between studies with the I² statistical index.

Result

We selected 39 eligible citations comprising 806 cases and 336 controls for the first dose and 6314 cases and 927 controls for the second dose for statistical analysis. After the first dose of mRNA vaccines, the seroconversion rate was 36% (95% confidence interval [CI]: 0.24–0.47) and 68% (95% CI: 0.45–0.91) in hemodialysis patients and the control group, respectively. While seroconversion rate after the second dose of mRNA vaccines was 86% (95% CI: 0.81–0.91) and 100% (95% CI: 1.00–1.00) in hemodialysis patients and the control group, respectively.

Conclusion

Although the immune response of hemodialysis patients to the second dose of the SARS‐CoV‐2 mRNA vaccine is very promising, the seroconversion rate of dialysis patients is lower than healthy controls. Periodically assessment of antibody levels of hemodialysis patients at short intervals is recommended.

The risk and consequences of breakthrough SARS-CoV-2 infection in solid organ transplant recipients relative to non-immunosuppressed controls

Clinical outcomes in solid organ transplant (SOT) recipients with breakthrough COVID (BTCo) after two doses of mRNA vaccination compared to the non-immunocompromised/immunosuppressed (ISC) general population, are not well described. In a cohort of adult patients testing positive for COVID-19 between December 10, 2020 and April 4, 2022, we compared the cumulative incidence of BTCo in a non-ISC population to SOT recipients (overall and by organ type) using the National COVID Cohort Collaborative (N3C) including data from 36 sites across the United States. We assessed the risk of complications post-BTCo in vaccinated SOT recipients versus SOT with unconfirmed vaccination status (UVS) using multivariable Cox proportional hazards and logistic regression. BTCo occurred in 4776 vaccinated SOT recipients over a median of 149 days (IQR 99-233), with the highest cumulative incidence in heart recipients. The relative risk of BTCo was greatest in SOT recipients (relative to non-ISC) during the pre-Delta period (HR 2.35, 95% CI 1.80-3.08). The greatest relative benefit with vaccination for both non-ISC and SOT cohorts was in BTCo mortality (HR 0.37, 95% CI 0.36-0.39 for non-ISC; HR 0.67, 95% 0.57-0.78 for SOT relative to UVS). While the relative benefit of vaccine was less in SOT than non-ISC, SOT patients still exhibited significant benefit with vaccination.

Response to SARS-CoV-2 vaccines in patients receiving B-cell modulating antibodies for renal autoimmune disease

Background

Effective SARS-CoV-2 vaccination in patients receiving treatment with B-cell depleting agents is challenging. Information on vaccination responses in these patients are a valuable tool to develop efficient vaccination regimens.

Methods

In this single-center retrospective observational study, we report the humoral and cellular response in 34 patients receiving anti-CD20 antibody treatment for renal immune disease.

Results

After base immunization with SARS-CoV-2-vaccines, 92.0% developed a cellular, 32.4% a humoral response. Humoral immunity correlated with B-cell counts and the timespan between anti-CD20 antibody treatment and vaccination. All patients with > 21/µl B-cells, or > 197 days after treatment showed humoral response.

Conclusions

Adequate timing of SARS-CoV-2-vaccinations after anti-CD20 antibody treatment and CD19 measurements are crucial to generate immunity. Awaiting partial B-cell recovery by postponing regularly scheduled anti-CD20 treatment should be considered in patients with stable immune disease.

Trial registration: This study has been retrospectively registered in the German Clinical Trials Register (DRKS00027049) on 29/10/2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07722-7.

Immune response to third SARS-CoV-2 vaccination in seronegative kidney transplant recipients: Possible improvement by mycophenolate mofetil reduction

Modification of vaccination strategies is necessary to improve the immune response to SARS-CoV-2 vaccination in kidney transplant recipients (KTRs). This multicenter observational study analyzed the effects of the third SARS-CoV-2 vaccination in previously seronegative KTRs with the focus on temporary mycophenolate mofetil (MMF) dose reduction within propensity matched KTRs. 56 out of 174 (32%) previously seronegative KTRs became seropositive after the third vaccination with only three KTRs developing neutralizing antibodies against the omicron variant. Multivariate logistic regression revealed that initial antibody levels, graft function, time after transplantation and MMF trough levels had an influence on seroconversion (P < .05). After controlling for confounders, the effect of MMF dose reduction before the third vaccination was calculated using propensity score matching. KTRs with a dose reduction of ≥33% showed a significant decrease in MMF trough levels to 1.8 (1.2-2.5) μg/ml and were more likely to seroconvert than matched controls (P = .02). Therefore, a MMF dose reduction of 33% or more before vaccination is a promising approach to improve success of SARS-CoV-2 vaccination in KTRs.

Efficacy and Safety of COVID-19 Vaccine in Patients on Renal Replacement Therapy

Patients with CKD on RRT are at high risk for severe disease and mortality in COVID-19 disease. We decided to conduct an observational prospective study to evaluate antibody response after vaccination for COVID-19 in a cohort of 210 adult patients on RRT (148 on HD; 20 on PD; and 42 kidney transplant recipients). Blood samples were taken before and 4 weeks after vaccination. Antibody levels were evaluated with CLIA immunoassay testing for IgG anti-trimeric spike protein of SARS-CoV-2. A positive antibody titer was present in 89.9% of HD patients, 90% of PD patients, and 52.4% of kidney transplant recipients. Non-responders were more frequent among patients on immunosuppressive therapy. Mycophenolate use in kidney transplant patients was associated with lower antibody response. The median antibody titer was 626 (228–1480) BAU/mL; higher in younger patients and those previously exposed to the virus and lower in HD patients with neoplasms and/or on immunosuppressive therapy. Only two patients developed COVID-19 in the observation period: they both had mild disease and antibody titers lower than 1000 BAU/mL. Our data show a valid response to COVID-19 mRNA vaccination in HD and PD patients and a reduced response in kidney transplant recipients. Mycophenolate was the most relevant factor associated with low response.

Clinical efficacy of SARS-CoV-2 vaccination in hemodialysis patients

Introduction

The COVID-19 pandemic is a global public health problem. Patients with end-stage renal disease on hemodialysis are at a higher risk of infection and mortality than the general population. Worldwide, a vaccination campaign has been developed that has been shown to reduce severe infections and deaths in the general population. However, there are currently limited data on the clinical efficacy of vaccinations in the hemodialysis population.

Methods

A national multicenter observational cohort was performed in Chile to evaluate the clinical efficacy of anti-SARS-CoV-2 vaccination in end-stage renal disease patients on chronic hemodialysis from February 2021 to August 2021. In addition, the BNT162b2 (Pfizer-BioNTech) and CoronaVac (Sinovac) vaccines were evaluated. The efficacy of vaccination in preventing SARS-CoV-2 infection, hospitalizations, and deaths associated with COVID-19 was determined.

Results

A total of 12,301 patients were evaluated; 10,615 (86.3%) received a complete vaccination (2 doses), 490 (4.0%) received incomplete vaccination, and 1196 (9.7%) were not vaccinated. During follow-up, 1362 (11.0%) patients developed COVID-19, and 150 died (case fatality rate: 11.0%). The efficacy of the complete vaccination in preventing infection was 18.1% (95% confidence interval [CI]:11.8–23.8%), and prevention of death was 66.0% (95% CI:60.6–70.7%). When comparing both vaccines, BNT162b2 and CoronaVac were effective in reducing infection and deaths associated with COVID-19. Nevertheless, the BNT162b2 vaccine had higher efficacy in preventing infection (42.6% vs. 15.0%) and deaths (90.4% vs. 64.8%) compared to CoronaVac.

Conclusion

The results of our study suggest that vaccination against SARS-CoV-2 in patients on chronic hemodialysis was effective in preventing infection and death associated with COVID-19.

Evaluation of the correlation between responders and non-responders to the second coronavirus disease vaccination in kidney transplant recipients: A retrospective single-center cohort study

Background

The immune response to COVID-19 vaccination in kidney transplant (KTx) recipients is significantly lower than that in healthy controls. We evaluated immune responses after the COVID-19 vaccine and their possible relationship with other cofactors in KTx recipients.

Methods

This retrospective single-center cohort study included 29 KTx recipients 2-8 weeks after receiving 2 doses of the Pfizer-BioNTech SARS-CoV-2 messenger RNA vaccine. Anti-SARS-CoV-2 spike (S) immunoglobulin (Ig)-G levels were evaluated to define cofactors influencing the immune response between the responder (anti-SARS-CoV-2 IgG level ≥0.8 U/mL) (n = 16) and nonresponder groups (anti-SARS-CoV-2 IgG level <0.8 U/mL) (n = 13). The kinetics of antibodies between 2 and 6 months after the second vaccination was also compared between the groups.

Results

KTx recipients with IgG levels ≥0.8 U/mL were younger (54 [interquartile range {IQR}, 46.5-61] years vs 65 [IQR, 55-71.5] years; P = .01), had been transplanted for a longer median time (1588 [IQR, 1382-4751] days vs 1034 [IQR, 548.5-1833] days; P = .02), and were more often treated with a lower mycophenolate mofetil dosage (765.6 ± 119.6 vs 1077 ± 76.9 mg; P = .04) than KTx recipients with IgG levels <0.8 U/mL. There was no significant difference in antibody titers between time periods after the second dose in the responder group. At the 6-month follow-up, a serologic response against the SARS-CoV-2 S was observed in 44.4% of KTx recipients in the nonresponder group.

Conclusions

More than 50% of KTx recipients developed a higher antibody response after the second dose of COVID-19 vaccination.

Seroprevalence of SARS-CoV-2 spike IgG antibodies after the second BNT162b2 mRNA vaccine in Japanese kidney transplant recipients

We aimed to evaluate the seroprevalence and investigated factors associated with seropositivity after the second SARS-CoV-2 mRNA vaccination in kidney transplant (KT) recipients. This retrospective study conducted between June and November 2021 included 106 KT recipients and 127 healthy controls who received the second dose of the BNT162b2 mRNA vaccine at least 7 days before the measurement of antibody titers. The antibody titer against the receptor-binding domain of SARS-CoV-2 spike (S) protein was determined. We compared seroprevalence rates (immunoglobulin G [IgG] level of ≥ 0.8 or ≥ 15 U/mL) between the healthy controls and KT recipients and identified factors associated with impaired humoral response. The seroprevalence rate of the healthy controls and KT recipients was 98% and 22%, respectively. Univariate logistic regression analysis revealed that age > 53 years, rituximab use, mycophenolate mofetil use, and KT vintage < 7 years were negatively associated with the rate of anti-SARS-CoV-2 S IgG ≥ 15 U/mL in KT recipients. ABO blood type incompatible KT was not significantly associated with seroprevalence. Humoral response after the second BNT162b2 mRNA vaccine was greatly hindered by immunosuppression therapy in KT recipients. Older age, rituximab use, mycophenolate mofetil use, and KT vintage may play key roles in seroconversion.

Effect of active anticancer therapy on serologic response to SARS-CoV-2 BNT162b2 vaccine in patients with urothelial and renal cell carcinoma

Objectives

To evaluate the serologic response to the BNT162b2 messenger ribonucleic acid vaccine in patients with urothelial carcinoma and renal cell carcinoma.

Methods

Between June 2021 and November 2021, we retrospectively evaluated blood samples from 60 healthy controls (control group), 57 patients with urothelial carcinoma, and 28 patients with renal cell carcinoma who had received two doses of the BNT162b2 vaccine at Hirosaki University Hospital. We determined the immunoglobulin G antibody titers against the severe acute respiratory syndrome coronavirus 2 spike receptor‐binding domain. Seropositivity was defined as ≥15 U/mL. We investigate factors associated with antibody titers and seropositivity in the patients with urothelial carcinoma and renal cell carcinoma.

Results

Antibody titers in the control, urothelial carcinoma, and renal cell carcinoma groups were 813, 431, and 500 U/mL, respectively. Seropositivity was 100%, 90%, and 96% in the control, urothelial carcinoma, and renal cell carcinoma groups, respectively. Of the 85 patients, 37 of 57 (65%) and 21 of 28 (75%) were actively undergoing anticancer treatment for urothelial carcinoma and renal cell carcinoma, respectively. Anti‐severe acute respiratory syndrome coronavirus 2 spike immunoglobulin G antibody titers and seropositivity was not significantly different between the patients with urothelial carcinoma and renal cell carcinoma. Anti‐severe acute respiratory syndrome coronavirus 2 spike immunoglobulin G antibody titers were not significantly associated with active anticancer therapy or steroid treatment for immune‐related adverse events. Univariable logistic regression analysis revealed that older age and metastatic disease were significantly and negatively associated with seropositivity.

Conclusions

Patients with urothelial carcinoma or renal cell carcinoma exhibited an adequate antibody response to the BNT162b2 vaccine. Active anticancer therapy was not significantly associated with seropositivity following vaccination with severe acute respiratory syndrome coronavirus 2 BNT162b2 in patients with urothelial carcinoma and renal cell carcinoma.

Intensity of mycophenolate mofetil treatment is associated with an impaired immune response to SARS-CoV-2 vaccination in kidney transplant recipients

Kidney transplant recipients (KTRs) are extremely vulnerable to SARS-CoV-2 infection and show an impaired immune response to SARS-CoV-2 vaccination. We analyzed factors related to vaccination efficiency in KTRs. In a multicenter prospective observational study (NCT04743947), IgG antibodies levels against SARS-CoV-2 spike S1 subunit and their neutralization capacity after SARS-CoV-2 vaccination were analyzed in 225 KTRs and compared to 176 controls. After the vaccination, 56 (24.9%) KTRs became seropositive of whom 68% had neutralizing antibodies. This immune response was significantly lower compared to controls (239 [78-519] BAU/ml versus 1826 [560-3180] BAU/ml for KTRs and controls, p < .0001). The strongest predictor for an impaired response was mycophenolate mofetil (MMF) treatment. Multivariate regression analysis revealed that MMF-free regimen was highly associated with seroconversion (OR 13.25, 95% CI 3.22-54.6; p < .001). In contrast, other immunosuppressive drugs had no significant influence. 187 out of 225 KTRs were treated with MMF of whom 26 (13.9%) developed antibodies. 23 of these seropositive KTRs had a daily MMF dose ≤1 g. Furthermore, higher trough MMF concentrations correlated with lower antibody titers (R -0.354, p < .001) supporting a dose-dependent unfavorable effect of MMF. Our data indicate that MMF dose modification could lead to an improved immune response.

Anti-SARS-CoV-2 Antibody Level among Renal Transplant Recipients: A Case Report from Nepal

Globally, SARS-CoV-2 has caused significant public health burden, mainly in patients with underlying comorbidities including both communicable and noncommunicable diseases. Solid organ transplant recipients under immunesupressive medication are also amongst the high risk group. There is only sparse data on immunity against SARS-CoV-2 infection among renal transplant recipients. In this case report, we present the level of anti-SARS-CoV-2 antibody of three kidney transplant recipients after vaccination against COVID-19 virus. All three cases had received two doses of Oxford-AstraZeneca COVID-19 vaccine AZD1222 (ChAdOx1). Serological analysis showed protective level of circulating antibodies in the blood of all three cases. Although two out of three patients in the study acquired COVID-19 infection after immunization, they recovered with mild clinical course. Hence, we conclude that despite immune-suppressed status of transplant recipients, COVID-19 vaccination could protect them against severe illness.

Increased one-year mortality in hemodialysis patients with COVID-19: a prospective, observational study

Background

Dialysis confers the highest risk of coronavirus disease 2019 (COVID-19) death among comorbidities predisposing to severe COVID-19. However, reports of COVID-19-associated mortality frequently refer to mortality during the initial hospitalization or first month after diagnosis.

Methods

In a prospective, observational study, we analysed the long-term (1-year follow-up) serological and clinical outcomes of 56 haemodialysis (HD) patients who were infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the first pandemic wave. COVID-19 was diagnosed by a positive polymerase chain reaction (PCR) test (n = 37) or by the development of anti-SARS-CoV-2 antibodies (n = 19).

Results

After >1 year of follow-up, 35.7% of HD patients infected by SARS-CoV-2 during the first pandemic wave had died, 6 (11%) during the initial admission and 14 (25%) in the following months, mainly within the first 3 months after diagnosis. Overall, 30% of patients died from vascular causes and 40% from respiratory causes. In adjusted analysis, a positive SARS-CoV-2 PCR test for diagnosis {hazard ratio [HR] 5.18 [interquartile range (IQR) 1.30–20.65], P = 0.020}, higher baseline C-reactive protein levels [HR 1.10 (IQR 1.03–1.16), P = 0.002] and lower haemoglobin levels [HR 0.62 (IQR 0.45–0.86), P = 0.005] were associated with higher 1-year mortality. Mortality in the 144 patients who did not have COVID-19 was 21 (14.6%) over 12 months [HR of death for COVID-19 patients 3.00 (IQR 1.62–5.53), log-rank P = 0.00023]. Over the first year, the percentage of patients having anti-SARS-CoV-2 immunoglobulin G (IgG) decreased from 36/49 (73.4%) initially to 27/44 (61.3%) at 6 months and 14/36 (38.8%) at 12 months.

Conclusions

The high mortality of HD patients with COVID-19 is not limited to the initial hospitalization. Defining COVID-19 deaths as those occurring within 3 months of a COVID-19 diagnosis may better represent the burden of COVID-19. In HD patients, the anti-SARS-CoV-2 IgG response was suboptimal and short-lived.

Humoral and Cellular Vaccination Responses against SARS-CoV-2 in Hematopoietic Stem Cell Transplant Recipients

The cellular response to SARS-CoV-2 vaccination and infection in allogeneic hematopoietic stem cell transplant (HSCT) recipients is not yet clear. In the current study, HSCT recipients prior to and post vaccination were tested for SARS-CoV-2-specific humoral and cellular immunity. Antibodies against spike (S) 1 were assessed by Anti-SARS-CoV-2 IgG ELISA (Euroimmun). Cellular immunity was analyzed by an in house interferon-gamma ELISpot and T-SPOT.COVID (Oxford Immunotec), using altogether seven SARS-CoV-2-specific antigens. In 117 HSCT patients vaccinated twice, SARS-CoV-2 IgG antibodies were significantly higher than in HSCT controls pre vaccination (p < 0.0001). After the second vaccination, we observed a median antibody ratio of 4.7 and 68% positive results, whereas 35 healthy controls reached a median ratio of 9.0 and 100% positivity. ELISpot responses in patients were significantly (p < 0.001) reduced to ≤33% of the controls. After the second vaccination, female HSCT patients and female healthy controls showed significantly higher antibody responses than males (6.0 vs. 2.1 and 9.2 vs. 8.2, respectively; p < 0.05). Cellular immunity was diminished in patients irrespective of sex. In conclusion, especially male HSCT recipients showed impaired antibody responses after SARS-CoV-2 vaccination. Changing the vaccine schedule or composition could help increase vaccine responses.