Post COVID-19 condition imposes significant burden in patients with advanced chronic kidney disease: A nested case-control study

BACKGROUND

The burden of post COVID-19 condition (PCC) is not well studied in patients with advanced kidney disease.

METHODS

A large prospective cohort of SARS-CoV-2 vaccinated patients with chronic kidney disease stages G4-G5 (CKD G4/5), on dialysis, and kidney transplant recipients (KTR) were included. Antibody levels were determined after vaccination. Presence of long-lasting symptoms was assessed in patients with and without prior COVID-19 and compared using logistic regression. In patients with prior COVID-19, PCC was defined according to the WHO definition.

RESULTS

Two hundred sixteen CKD G4/5 patients, 375 dialysis patients, and 2005 KTR were included. Long-lasting symptoms were reported in 204/853 (24%) patients with prior COVID-19 and in 297/1743 (17%) patients without prior COVID-19 (aOR: 1.45 (1.17-1.78)], P < 0.001). PCC was prevalent in 29% of CKD G4/5 patients, 21% of dialysis patients, and 24% of KTR. In addition, 69% of patients with PCC reported (very) high symptom burden. Odds of PCC was lower per 10-fold increase in antibody level after vaccination (aOR 0.82 [0.70-0.96], P = 0.01) and higher in case of COVID-19 related hospital admission (aOR 4.64 [2.61-8.25], P = 0.003).

CONCLUSIONS

CKD G4/5 patients, dialysis patients, and KTR are at risk for PCC with high symptom burden after SARS-CoV-2 vaccination, especially if antibody levels are low and in case of hospitalization due to COVID-19.

Incidence and Severity of COVID-19 in Relation to Anti-Receptor-Binding Domain IgG Antibody Level after COVID-19 Vaccination in Kidney Transplant Recipients

Kidney transplant recipients (KTRs) elicit an impaired immune response after COVID-19 vaccination; however, the exact clinical impact remains unclear. We therefore analyse the relationship between antibody levels after vaccination and the risk of COVID-19 in a large cohort of KTRs. All KTRs living in the Netherlands were invited to send a blood sample 28 days after their second COVID-19 vaccination for measurement of their IgG antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein (anti-RBD IgG). Information on COVID-19 was collected from the moment the blood sample was obtained until 6 months thereafter. Multivariable Cox and logistic regression analyses were performed to analyse which factors affected the occurrence and severity (i.e., hospitalization and/or death) of COVID-19. In total, 12,159 KTRs were approached, of whom 2885 were included in the analyses. Among those, 1578 (54.7%) became seropositive (i.e., anti-RBD IgG level >50 BAU/mL). Seropositivity was associated with a lower risk for COVID-19, also after adjusting for multiple confounders, including socio-economic status and adherence to COVID-19 restrictions (HR 0.37 (0.19-0.47), p = 0.005). When studied on a continuous scale, we observed a log-linear relationship between antibody level and the risk for COVID-19 (HR 0.52 (0.31-0.89), p = 0.02). Similar results were found for COVID-19 severity. In conclusion, antibody level after COVID-19 vaccination is associated in a log-linear manner with the occurrence and severity of COVID-19 in KTRs. This implies that if future vaccinations are indicated, the aim should be to reach for as high an antibody level as possible and not only seropositivity to protect this vulnerable patient group from disease.

Differences in mental health status during the COVID-19 pandemic between patients undergoing in-center hemodialysis and peritoneal dialysis

BACKGROUND

The mental health of dialysis patients during the COVID-19 pandemic may have been modulated by dialysis modality. Studies comparing mental health of in-center hemodialysis and peritoneal dialysis patients during the first 2 years of the pandemic are lacking.

METHODS

We conducted repeated cross-sectional and multivariable regression analyses to compare the mental health of in-center hemodialysis and peritoneal dialysis patients from March 2019 until August 2021 using data from the Dutch nOcturnal and hoME dialysis Study To Improve Clinical Outcomes. The study period was divided into one pre-pandemic and six 3-month pandemic periods (period 1-period 6). Mental health was assessed with the Mental Component Summary score of the 12-item Short Form health survey and mental symptoms of the Dialysis Symptom Index.

RESULTS

We included 1274 patients (968 on in-center hemodialysis and 306 on peritoneal dialysis). Mental Component Summary scores did not differ between in-center hemodialysis and peritoneal dialysis patients. In contrast, in-center hemodialysis patients more often reported nervousness during period 3 (27% vs 15%, P = 0.04), irritability and anxiety during period 3 (31% vs 18%, P = 0.03, 26% vs. 9%, P = 0.002, respectively) and period 4 (34% vs 22%, P = 0.04, 22% vs 11%, P = 0.03, respectively), and sadness in period 4 (38% vs 26%, P = 0.04) and period 5 (37% vs 22%, P = 0.009). Dialysis modality was independently associated with mental symptoms.

CONCLUSIONS

In-center hemodialysis patients more often experienced mental symptoms compared to peritoneal dialysis patients from September 2020 to June 2021, which corresponds to the second lockdown of the COVID-19 pandemic. Mental health-related quality-of-life did not differ between in-center hemodialysis and peritoneal dialysis patients.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register NL6519, date of registration: 22 August, 2017.

Adherence to preventive measures after SARS-CoV-2 vaccination and after awareness of antibody response in kidney transplant recipients in the Netherlands: a nationwide questionnaire study

Background

Kidney transplant recipients (KTRs) were advised to tightly adhere to government recommendations to curb the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) because of a high risk of morbidity and mortality and decreased immunogenicity after vaccination. The aim of this study was to analyse the change in adherence to preventive measures after vaccination and awareness of antibody response, and to evaluate its effectiveness.

Methods

In this large-scale, national questionnaire study, questionnaires were sent to 3531 KTRs enrolled in the Dutch RECOVAC studies, retrospectively asking for adherence to nine preventive measures on a 5-point Likert scale before and after SARS-CoV-2 vaccination and after awareness of antibody response. Blood samples were collected 28 days after the second vaccination. Antibody response was categorised as non-responder (≤50 BAU/mL), low-responder (>50 ≤ 300 BAU/mL) or high-responder (>300 BAU/mL), and shared with participants as a correlate of protection. Participants of whom demographics on sex and age, blood samples and completed questionnaires were available, were included. Our study took place between February 2021 and January 2022. The primary outcome of adherence before and after vaccination was assessed between August and October 2021 and compared via the Wilcoxon signed rank sum test. Logistic regression analysis was performed to estimate the association between antibody response and non-adherence, and adherence on acquiring SARS-CoV-2 infection. This study is registered at ClinicalTrials.gov (NCT04841785).

Findings

In 2939 KTRs (83%) who completed the first questionnaire on adherence to preventive measures, adherence was higher before than after vaccination (4.56, IQR 4.11-4.78 and 4.22, IQR 3.67-4.67, p < 0.001). Adherence after awareness of antibody response was analysed in 2399 KTRs (82%) of whom also blood samples were available, containing 949 non-responders, 500 low-responders and 950 high-responders. Compared to non-responders, low- and high-responders reported higher non-adherence. Higher adherence was associated with lower infection rates before and after vaccination (OR 0.67 [0.51-0.91], p = 0.008 and OR 0.48 [0.28-0.86], p = 0.010).

Interpretation

Adherence decreased after SARS-CoV-2 vaccination and in KTRs who were aware of a subsequent antibody response compared with those without. Preventive measures in this vulnerable group seem to be effective, regardless of vaccination status. This study starts a debate on sharing antibody results with the patient and future studies should elucidate whether decreased adherence in antibody responders is justified, also in view of future pandemics.

Funding

The Netherlands Organization for Health Research and Development and the Dutch Kidney Foundation.

Alternative strategies to increase the immunogenicity of COVID-19 vaccines in kidney transplant recipients not responding to two or three doses of an mRNA vaccine (RECOVAC): a randomised clinical trial

BACKGROUND

An urgent need exists to improve the suboptimal COVID-19 vaccine response in kidney transplant recipients (KTRs). We aimed to compare three alternative strategies with a control single dose mRNA-1273 vaccination: a double vaccine dose, heterologous vaccination, and temporary discontinuation of mycophenolate mofetil or mycophenolic acid.

METHODS

This open-label randomised trial, done in four university medical centres in the Netherlands, enrolled KTRs without seroconversion after two or three doses of an mRNA vaccine. Between Oct 20, 2021, and Feb 2, 2022, 230 KTRs were randomly assigned block-wise per centre by a web-based system in a 1:1:1 manner to receive 100 μg mRNA-1273, 2 × 100 μg mRNA-1273, or Ad26.COV2-S vaccination. In addition, 103 KTRs receiving 100 μg mRNA-1273, were randomly assigned 1:1 to continue (mycophenolate mofetil+) or discontinue (mycophenolate mofetil-) mycophenolate mofetil or mycophenolic acid treatment for 2 weeks. The primary outcome was the percentage of participants with a spike protein (S1)-specific IgG concentration of at least 10 binding antibody units per mL at 28 days after vaccination, assessed in all participants who had a baseline measurement and who completed day 28 after vaccination without SARS-CoV-2 infection. Safety was assessed as a secondary outcome in all vaccinated patients by incidence of solicited adverse events, acute rejection or other serious adverse events. This trial is registered with ClinicalTrials.gov, NCT05030974 and is closed.

FINDINGS

Between April 23, 2021, and July 2, 2021, of 12 158 invited Dutch KTRs, 3828 with a functioning kidney transplant participated in a national survey for antibody measurement after COVID-19 vaccination. Of these patients, 1311 did not seroconvert after their second vaccination and another 761 not even after a third. From these seronegative patients, 345 agreed to participate in our repeated vaccination study. Vaccination with 2 × mRNA-1273 or Ad26.COV2-S was not superior to single mRNA-1273, with seroresponse rates of 49 (68%) of 72 (95% CI 56-79), 46 (63%) of 73 (51-74), and 50 (68%) of 73 (57-79), respectively. The difference with single mRNA-1273 was -0·4% (-16 to 15; p=0·96) for 2 × mRNA-1273 and -6% (-21 to 10; p=0·49) for Ad26.COV2-S. Mycophenolate mofetil- was also not superior to mycophenolate mofetil+, with seroresponse rates of 37 (80%) of 46 (66-91) and 31 (67%) of 46 (52-80), and a difference of 13% (-5 to 31; p=0·15). Local adverse events were more frequent after a single and double dose of mRNA-1273 than after Ad26.COV2-S (65 [92%] of 71, 67 [92%] of 73, and 38 [50%] of 76, respectively; p<0·0001). No acute rejection occurred. There were no serious adverse events related to vaccination.

INTERPRETATION

Repeated vaccination increases SARS-CoV-2-specific antibodies in KTRs, without further enhancement by use of a higher dose, a heterologous vaccine, or 2 weeks discontinuation of mycophenolate mofetil or mycophenolic acid. To achieve a stronger response, possibly required to neutralise new virus variants, repeated booster vaccination is needed.

FUNDING

The Netherlands Organization for Health Research and Development and the Dutch Kidney Foundation.

Mycophenolic Acid Exposure Determines Antibody Formation Following SARS-CoV-2 Vaccination in Kidney Transplant Recipients: A Nested Cohort Study

Despite (repeated) boosting, kidney transplant recipients (KTRs) may remain at increased risk of severe COVID-19 since a substantial number of individuals remain seronegative or with low antibody titers. In particular, mycophenolic acid use has been shown to affect antibody formation negatively and may be an important modifiable risk factor. We investigated the exposure-response relationship between mycophenolic acid 12-hour area under the curve (AUC_0-12h ) exposure and seroconversion including antibody titers after vaccination using mRNA-1273 SARS-CoV-2 vaccine (Moderna) in 316 KTRs from our center that participated in the national Dutch renal patients COVID-19 vaccination - long term efficacy and safety of SARS-CoV-2 vaccination in kidney disease patients vaccination study. After two vaccination doses, 162 (51%) KTRs seroconverted. KTRs treated with mycophenolic acid showed less seroconversion and lower antibody titers compared with KTRs without mycophenolic acid (44% vs. 77%, and 36 binding antibody units (BAU)/mL vs. 340 BAU/mL; P < 0.001). The mean mycophenolic acid AUC_0-12h exposure was significantly lower in KTRs who seroconverted compared with KTRs who did not (39 vs. 29 mg⋅h/L; P < 0.001). High mycophenolic acid exposure (±90 mg⋅h/L) and no exposure to mycophenolic acid resulted in a seroconversion rate ranging from 10% to 80%. Every 10 mg⋅h/L increase in mycophenolic acid AUC_0-12h gave an adjusted odds ratio for seroconversion of 0.87 (95% confidence interval (CI), 0.79-0.97; P = 0.010) and 0.89 (95% CI, 0.85-0.93; P < 0.001) for KTRs on dual and triple maintenance immunosuppressive therapy, respectively. Higher mycophenolic acid AUC_0-12h correlated with lower antibody titers (R = 0.44, P < 0.001). This study demonstrates the exposure-response relationship between gold standard mycophenolic acid exposure and antibody formation to support interventional studies investigating mycophenolic acid adjustment to improve antibody formation after further boosting.

Impact of immunosuppressive treatment and type of SARS-CoV-2 vaccine on antibody levels after three vaccinations in patients with chronic kidney disease or kidney replacement therapy

Background

Patients with chronic kidney disease (CKD) or kidney replacement therapy demonstrate lower antibody levels after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination compared with healthy controls. In a prospective cohort, we analysed the impact of immunosuppressive treatment and type of vaccine on antibody levels after three SARS-CoV-2 vaccinations.

Methods

Control subjects (n = 186), patients with CKD G4/5 (n = 400), dialysis patients (n = 480) and kidney transplant recipients (KTR) (n = 2468) were vaccinated with either mRNA-1273 (Moderna), BNT162b2 (Pfizer-BioNTech) or AZD1222 (Oxford/AstraZeneca) in the Dutch SARS-CoV-2 vaccination programme. Third vaccination data were available in a subgroup of patients (n = 1829). Blood samples and questionnaires were obtained 1 month after the second and third vaccination. Primary endpoint was the antibody level in relation to immunosuppressive treatment and type of vaccine. Secondary endpoint was occurrence of adverse events after vaccination.

Results

Antibody levels after two and three vaccinations were lower in patients with CKD G4/5 and dialysis patients with immunosuppressive treatment compared with patients without immunosuppressive treatment. After two vaccinations, we observed lower antibody levels in KTR using mycophenolate mofetil (MMF) compared with KTR not using MMF [20 binding antibody unit (BAU)/mL (3-113) vs 340 BAU/mL (50-1492), P < .001]. Seroconversion was observed in 35% of KTR using MMF, compared with 75% of KTR not using MMF. Of the KTR who used MMF and did not seroconvert, eventually 46% seroconverted after a third vaccination. mRNA-1273 induces higher antibody levels as well as a higher frequency of adverse events compared with BNT162b2 in all patient groups.

Conclusions

Immunosuppressive treatment adversely affects the antibody levels after SARS-CoV-2 vaccination in patients with CKD G4/5, dialysis patients and KTR. mRNA-1273 vaccine induces a higher antibody level and higher frequency of adverse events.

The clinical frailty scale as a triage tool for ICU admission of dialysis patients with COVID-19 - An ERACODA analysis

Background

Several guidelines recommend using the Clinical Frailty Scale (CFS) for triage of critically ill coronavirus disease 2019 (COVID-19) patients. This study evaluates the impact of CFS on intensive care unit (ICU) admission rate and hospital and ICU mortality rates in hospitalized dialysis patients with COVID-19.

Methods

We analysed data of dialysis patients diagnosed with COVID-19 from the European Renal Association COVID-19 Database. The primary outcome was ICU admission rate and secondary outcomes were hospital and ICU mortality until 3 months after COVID-19 diagnosis. Cox regression analyses were performed to assess associations between CFS and outcomes.

Results

A total of 1501 dialysis patients were hospitalized due to COVID-19, of whom 219 (15%) were admitted to an ICU. The ICU admission rate was lowest (5%) in patients >75 years of age with a CFS of 7–9 and highest (27%) in patients 65–75 years of age with a CFS of 5. A CFS of 7–9 was associated with a lower ICU admission rate than a CFS of 1–3 [relative risk 0.49 (95% confidence interval 0.27–0.87)]. Overall, mortality at 3 months was 34% in hospitalized patients, 65% in ICU-admitted patients and highest in patients >75 years of age with a CFS of 7–9 (69%). Only 9% of patients with a CFS ≥6 survived after ICU admission. After adjustment for age and sex, each CFS category ≥4 was associated with higher hospital and ICU mortality compared with a CFS of 1–3.

Conclusions

Frail dialysis patients with COVID-19 were less frequently admitted to the ICU. Large differences in mortality rates between fit and frail patients suggest that the CFS may be a useful complementary triage tool for ICU admission in dialysis patients with COVID-19.

MO337: Higher Antibody Response After 2 Vaccinations With MRNA-1273 as Compared With BNT162B2 and AZD1222 in High-Risk Kidney Patients

BACKGROUND AND AIMS

Lower antibody responses after SARS-Cov-2 vaccination have been reported in patients with severely impaired kidney function or patients with kidney replacement treatment. We compared humoral responses and reported adverse events of three vaccines (mRNA-1273, BNT162b2 and AZD1222) in kidney transplant recipients (KTRs), dialysis patients, patients with CKD stages G4–G5 and control subjects without kidney disease.

METHOD

KTRs, dialysis patients and patients with CKD stages G4–G5 were vaccinated with either mRNA-1273, BNT162b2 or AZD1222 during the Dutch SARS-CoV-2 vaccination program. Control subjects were all vaccinated with mRNA-1273. Blood samples were obtained at 1 month after two vaccinations by home-based finger prick tests and were analysed for the presence of IgG antibodies against the receptor-binding domain of the spike protein of SARS-CoV-2 using the Sanquin anti-SARS-CoV-2 RBD IgG ELISA assay. Primary endpoints were the antibody titer and reported systemic adverse events (AEs) at 1 month after the second vaccination. Multivariate regression analysis was performed on the difference between vaccines with respect to antibody titer and AEs after correction for sex, ethnicity, BMI, eGFR, dialysis vintage, transplantation characteristics and use of immunosuppressive drugs.

RESULTS

A total of 2468 KTRs, 480 dialysis patients, 400 patients with CKD stages G4–G5 and 186 control subjects were enrolled. KTRs had lower antibody titers (66 [8–573] BAU/mL) in comparison to dialysis patients [1375 (431–2896) BAU/mL], patients with CKD stages G4–G5 [2097 (828–4077) BAU/mL] and control subjects [3713 (2291–6451) BAU/mL]. mRNA-1273 demonstrated a higher antibody titer compared with BNT162b2 in KTR [72 (9–638) versus 21 (6–128) BAU/mL; P &lt; .001), dialysis patients [1675 (573–3031) versus 636 (216–1416) BAU/mL; P &lt; .001] and patients with CKD stages G4–G5 [2879 (1425–5311) versus 1063 (389–1939) BAU/mL; P &lt; .001). In a similar pattern, mRNA-1273 demonstrated a higher antibody titer compared with AZD1222 (P &lt; .001 in all groups). Multivariate analysis revealed that BNT162b2 and AZD1222 were significantly associated with lower antibody levels compared with mRNA-1273 in all 3 patient groups. BNT162b2 demonstrated less frequently systemic AEs compared with mRNA-1273 in KTRs (12% versus 27%; P &lt; .001), dialysis patients (12% versus 29%; P = .007) and in patients with CKD G4–G5 (18% versus 67%, P &lt; .001). AZD1222 demonstrated less systemic AEs compared with mRNA-1273 only in patients with CKD stages G4–G5 (39% versus 67%; P = .03). Multivariate analysis revealed that BNT162b2 was associated with fewer systemic AEs in only dialysis patients (P = .04) and patients with CKD stages G4–G5 (P = .02).

CONCLUSION

mRNA-1273 demonstrated significantly higher antibody levels at 1 month after 2 vaccinations as compared with BNT162b2 and AZD1222 in high-risk patients with kidney disease. BNT162b2 was associated with a fewer systemic AEs in dialysis patients and patients with CKD stages G4–G5, although these AEs were mild and self-limiting. mRNA-1273 may therefore be considered as the preferred SARS-CoV-2 vaccine in high-risk patients with kidney disease. Whether the higher antibody response following vaccination with mRNA-1273 sustains and results in a better protection against COVID-19 is yet to be analysed.

MO184: Development and Validation of a Multivariable Prediction Model for Nonseroconversion after SARS-COV-2 Vaccination in Kidney Transplant Recipients

BACKGROUND AND AIMS

Kidney transplant recipients (KTRs) are still at risk of fatal COVID-19 disease after SARS-CoV-2 vaccination, even after a third booster vaccination. With the spread of new SARS-CoV-2 variants, great urgency exists for a better understanding of the factors that impact the immune response in these patients. Our aim was to predict nonseroconversion after SARS-CoV-2 vaccination to understand the factors that may disrupt the humoral response in KTRs.

METHOD

A multivariable logistic regression model was developed and validated that uses routinely available clinical and laboratory information to predict nonseroconversion after two doses of SARS-CoV-2 mRNA vaccination in KTRs. KTRs were prospectively enrolled to the Dutch REnal patients COVID-19 VACcination (RECOVAC) consortium, specifically to the Immune Response (IR) study with four participating university medical centres in the Netherlands. The discovery cohort consisted of three participating centres (Amsterdam UMC, Radboud UMC Nijmegen and Erasmus MC Rotterdam), and the validation cohort of patients treated in UMC Groningen. A large second validation set from the RECOVAC consortium (LESS-CoV-2) was used to test a more simplified version of the model without lymphocyte counts. All participants received two doses of the mRNA-1273 COVID-19 vaccine (Moderna) and had no history of SARS-CoV-2 infection. Participants were classified as responder or non-responder based on seroconversion at day 28 following the second vaccination with a threshold for seropositivity based on receiver operator curve analysis set at S1-specific IgG antibody concentration ≥10 BAU/mL.

RESULTS

The discovery cohort included 215 KTRs of which 126 responders and 89 non-responders. After backward selection, 6 out of 19 factors remained predictive for nonseroconversion: increased age, lower lymphocyte count, lower estimated glomerular filtration rate (eGFR), shorter time after transplantation, not using steroids and the use of mycophenolate mofetil/mycophenolic acid (MMF/MPA) (Figure 1). The area under the curve (AUC) of the receiver operating characteristics was 0.83 (95% confidence interval 0.78–0.89) in the discovery cohort after adjustment for optimism and 0.84 (0.74–0.94) in external validation of the UMC Groningen cohort (n = 73), and 0.75 (0.72–0.77) in external validation of the LESS-CoV-2 dataset (n = 2484). In addition, MMF/MPA appeared to have a dose-dependent unfavourable association with the S1 IgG antibody titer (Figure 2).

CONCLUSION

Six predictors allow for a better understanding of the process of the development of the humoral response in KTRs. These predictors could be applied to individualized patient counseling and treatment strategy during the COVID-19 pandemic and future innovative vaccine trial design for this complex patient group.

MO899: The Clinical frailty Scale is Useful for ICU Triage in Dialysis Patients With COVID-19–An Eracoda Analysis

BACKGROUND AND AIMS

during the COVID-19 pandemic, several guidelines have recommended the use of the Clinical Frailty Scale (CFS) for triage of critically ill patients with COVID-19 in case of shortage in ICU resources. However, no data on using CFS assessment for ICU triage for dialysis patients is yet available. This study evaluates whether CFS is associated with mortality rates in a cohort of hospitalized dialysis patients with COVID-19.

METHOD

the analyses are based on data of the European Renal Association COVID-19 Database (ERACODA). Dialysis patients who presented with COVID-19 between 1 February 2020 and 30 April 2021 and with complete information on CFS and vital status at 3 months were included. Study outcomes were hospital and ICU admission rates and hospital and ICU mortality at 3 months after hospital admission. Cox regression analyses were performed to assess the association of CFS category (≤5 versus ≥ 6) and study outcomes in line with Dutch ICU triage guidelines for COVID-19. Furthermore, additional subgroup analyses were performed to assess the association between CFS and 3-month mortality by age category (<65, 65–75 and >75 years).

RESULTS

among a total of 2206 dialysis patients (mean age = 67.2 (14.1) years, male sex = 61%), 1694 (77%) had CFS ≤ 5 and 514 (23%) had CFS ≥ 6. Hospitalization rate was comparable in patients with CFS ≤ 5 and in patients with CFS ≥ 6 (67 and 71%, respectively), whereas the rate of ICU admission was higher in patients with CFS ≤ 5 than in patients with CFS ≥ 6 (16 versus 9%, p = 0.001). Among 1501 hospitalized patients, 3-month mortality was 26% of patients with CFS ≤ 5 and 59% in patients with CFS ≥ 6 (P < 0.001). Multivariate analysis with adjustment for patient demographics, smoking status and BMI revealed that CFS ≥ 6 was associated with hospital mortality [aHR 2.27 (1.88–2.74) versus CFS ≤ 5; P < 0.001) with a significant interaction for age (P = 0.029). aHR was 4.00 (2.56–6.37; CFS ≥ 6 versus CFS ≤ 5; P < 0.001) in patients < 65 years, aHR was 1.87 (1.33–2.64; CFS ≥ 6 versus CFS ≤ 5; P < 0.001) in patients 65–75 years and aHR was 2.12 (1.64–2.75; CFS ≥ 6 versus CFS ≤ 5; P < 0.001) in patients >75 years. Among 219 ICU admitted patients, 3-month mortality was 60% of the patients with CFS ≤ 5 and 91% in the patients with CFS ≥ 6, respectively. Multivariate analysis with adjustment for patient demographics, smoking status and BMI revealed that CFS ≥ 6 was associated with ICU mortality [aHR 1.80 (1.17–2.77); CFS ≥ 6 versus CFS ≤ 5; P = 0.002].

CONCLUSION

more frail dialysis patients with CFS ≥ 6 who are hospitalized for COVID-19 were less often admitted to the ICU, but in case they were admitted to the ICU they have a very high mortality of 91% in this cohort study. In fit to mildly frail dialysis, patients who were admitted to the ICU, mortality rates are lower. The association between frailty and hospital mortality is interacted by age with the strongest association in patients younger than 65 years. These findings suggest that CFS may be a useful complementary triage tool for ICU admission of dialysis patients during the ongoing COVID-19 pandemic.

Long-term efficacy and safety of SARS-CoV-2 vaccination in patients with chronic kidney disease, on dialysis or after kidney transplantation: a national prospective observational cohort study

Background

COVID-19 is associated with increased morbidity and mortality in patients with chronic kidney disease (CKD) stages G4-G5, on dialysis or after kidney transplantation (kidney replacement therapy, KRT). SARS-CoV-2 vaccine trials do not elucidate if SARS-CoV-2 vaccination is effective in these patients. Vaccination against other viruses is known to be less effective in kidney patients. Our objective is to assess the efficacy and safety of various types of SARS-CoV-2 vaccinations in patients with CKD stages G4-G5 or on KRT.

Methods

In this national prospective observational cohort study we will follow patients with CKD stages G4-G5 or on KRT (n = 12,000) after SARS-CoV-2 vaccination according to the Dutch vaccination program. Blood will be drawn for antibody response measurements at day 28 and month 6 after completion of vaccination. Patient characteristics and outcomes will be extracted from registration data and questionnaires during 2 years of follow-up. Results will be compared with a control group of non-vaccinated patients. The level of antibody response to vaccination will be assessed in subgroups to predict protection against COVID-19 breakthrough infection.

Results

The primary endpoint is efficacy of SARS-CoV-2 vaccination determined as the incidence of COVID-19 after vaccination. Secondary endpoints are the antibody based immune response at 28 days after vaccination, the durability of this response at 6 months after vaccination, mortality and (serious) adverse events.

Conclusion

This study will fulfil the lack of knowledge on efficacy and safety of SARS-CoV-2 vaccination in patients with CKD stages G4-G5 or on KRT.

Trial registration

The study protocol has been registered in clinicaltrials.gov(NCT04841785).

Current knowledge about this subject

COVID-19 has devastating impact on patients with CKD stages G4-G5, on dialysis or after kidney transplantation.

Effective SARS-CoV-2 vaccination is very important in these vulnerable patient groups.

Recent studies on vaccination in these patient groups are small short-term studies with surrogate endpoints.

Contribution of this study

Assessment of incidence and course of COVID-19 after various types of SARS-CoV-2 vaccination during a two-year follow-up period in not only patients on dialysis or kidney transplant recipients, but also in patients with CKD stages G4-G5.

Quantitative analysis of antibody response after SARS-CoV-2 vaccination and its relationship with incidence and course of COVID-19 in patients with CKD stages G4-G5, on dialysis or after kidney transplantation compared with a control group.

Monitoring of (serious) adverse events and development of anti-HLA antibodies.

Impact on practice or policy

Publication of the study design contributes to harmonization of SARS-CoV-2 vaccine study

methodology in kidney patients at high-risk for severe COVID-19.

Data on efficacy of SARS-CoV-2 vaccination in patients with CKD will provide guidance for future vaccination policy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02680-3.