How Did the Omicron Surge Affect Kidney Transplant Recipients Compared With a Cohort From the General Population?

COVID-19 among kidney transplant recipients: evaluating risk factors during the initial phase of the pandemic

Background

Current knowledge about risk factors for severe COVID-19 among kidney transplant recipients stem from meta-analyses of small or regional studies.

Methods

All kidney transplant recipients in Sweden as of 1 January 2020 (n = 5824) were followed during the first 2 years of the pandemic. Data from the Swedish Renal Registry and linked health care registries were analyzed by multivariable adjusted logistic regression to identify risk factors for severe COVID-19, defined as hospitalization or death due to COVID-19.

Results

Male sex increased the risk of severe COVID-19. While many comorbidities were associated with increased risk, their significance diminished after adjustment for other factors. Kidney transplant recipients of working age, 49-58 years adjusted odds ratio (aOR) 2.32 (95% CI 1.53-3.51) and 59-68 years aOR (1.92; 1.26-2.91) had the highest risk compared to the youngest age group (18-38 years). Compared to recently (<1 year) transplanted patients, those transplanted >5 years ago had a lower risk of severe COVID-19 (aOR 0.52; 0.36-0.75 for 6-10 years; aOR 0.57; 0.41-0.79 for >10 years). Longer pre-transplant dialysis vintage (aOR1-year 1.04; 1.01-1.06) and deceased donor kidneys (aOR 1.41; 1.09-1.84) increased the risk. Immunosuppression with mycophenolate mofetil (aOR 1.47, 95% CI 1.08-1.99) and proton pump inhibitor use (aOR 1.58, 95% CI 1.24-2.01) were strongly associated with severe COVID-19.

Conclusions

While kidney transplant recipients share risk factors with the general population, working age groups were at the highest risk, unlike in the general population. These findings emphasize the need for targeted prevention and treatment strategies for kidney transplant recipients in future pandemics.

Safety and efficacy of tixagevimab/cilgavimab for pre-exposure prophylaxis in kidney transplant recipients: a multicenter retrospective cohort study

BACKGROUND

Immunocompromised patients show an impaired vaccine response and remain at high risk of severe COVID-19, despite vaccination. Neutralizing monoclonal antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed for prophylaxis and treatment. The combination tixagevimab/cilgavimab (AZD7442) has been authorized for emergency use as pre-exposure prophylaxis for COVID-19, but data on safety and efficacy in kidney transplant recipients during the Omicron period are limited.

METHODS

We conducted a multicenter retrospective cohort study including 253 kidney transplant recipients, of whom 98 were treated with tixagevimab/cilgavimab 150 mg/150 mg and 155 who received only four doses of the BNT162b2 mRNA vaccine.

RESULTS

Only 13.3% of patients developed SARS-CoV-2 infection after the administration of tixagevimab/cilgavimab; in comparison, 34.2% of patients had been infected after the fourth dose of vaccine (p = 0.00013). Most infected patients in the AZD7442 group remained asymptomatic (92.3% vs 54.7%), 7.7% had mild symptoms and none had severe disease, need for hospitalization or died, while in the control group, 9.4% of patients had moderate or severe disease (p = 0.04). Using Kaplan-Meier curves we demonstrated that the controls presented early infection compared to the AZD7442 group (p = 0.000014). No changes in eGFR or proteinuria, assessed before and after the administration, were observed.

CONCLUSIONS

In conclusion, our study showed that tixagevimab/cilgavimab 150/150 mg is effective and safe in preventing infection and severe disease when administered to patients with weak or no response to COVID-19 vaccine.

Prevention and treatment strategies for kidney transplant recipients in the context of long-term existence of COVID-19

The sudden outbreak of coronavirus disease 2019 (COVID-19) in early 2020 posed a massive threat to human life and caused an economic upheaval worldwide. Kidney transplant recipients (KTRs) became susceptible to infection during the COVID-19 pandemic owing to their use of immunosuppressants, resulting in increased hospitalization and mortality rates. Although the current epidemic situation is alleviated, the long-term existence of COVID-19 still seriously threatens the life and health of KTRs with low immunity. The Omicron variant, a highly infectious but less-pathogenic strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised concerns among transplant physicians regarding managing KTRs diagnosed with this variant. However, currently, there are no clear and unified guidelines for caring for KTRs infected with this variant. Therefore, we aimed to summarize the ongoing research on drugs that can treat Omicron variant infections in KTRs and explore the potential of adjusting immunotherapy strategies to enhance their responsiveness to vaccines. Herein, we discuss the situation of KTRs since the emergence of COVID-19 and focus on various prevention and treatment strategies for KTRs since the Omicron variant outbreak. We hope to assist physicians in managing KTRs in the presence of long-term COVID-19 variants.

Long COVID Among Kidney Transplant Recipients Appears to Be Attenuated During the Omicron Predominance

BACKGROUND

Omicron variant has been associated with milder cases of COVID-19 among kidney transplant recipients. However, little is known about postacute sequelae, referred to as Long COVID.

METHODS

Prospective, single-center cohort study investigating prevalence and risk factors for Long COVID among kidney transplant recipients during the omicron predominance in Brazil. The analysis included adult patients with confirmed SARS-CoV-2 infection between January 5, 2022, and July 18, 2022, were alive, had a functioning kidney transplant 3 mo after symptom onset, and answered a telephonic survey about physical complains of Long COVID.

RESULTS

From the 1529 eligible, 602 (39%) patients responded the survey. Sixteen percent reported a previous SARS-CoV-2 infection, and 85% had been fully vaccinated. The prevalence of Long COVID was 52%, with the most common complaints being weakness (46%), myalgia (41%), dizziness (33%), and headache (31%). Among employed patients, 94% were able to resume their normal work activities. In multivariable analysis, female gender (hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.51-3.02; P  < 0.0001), previous SARS-CoV-2 infection (HR, 3.55; 95% CI, 1.91-6.60; P  < 0.0001), fatigue (HR, 2.32; 95% CI, 1.18-4.55; P  = 0.014), myalgia (HR, 1.48; 95% CI, 1.03-2.15; P  = 0.036) during the acute phase, and hospitalization because of COVID-19 (HR, 1.71; 95% CI, 1.06-2.76; P  = 0.028) were independently associated with Long COVID.

CONCLUSIONS

In the "omicron era," Long COVID among kidney transplant recipients exhibited milder characteristics and had a less significant impact on their ability to resume normal life activities. The risk factors for persistent symptoms were similar to those observed in the general population except for the vaccination status, underscoring the importance of closer monitoring in special subgroups.

Excess mortality among kidney transplant recipients: Impact of COVID-19-related deaths during the pandemic

BACKGROUND

Because COVID-19 has been associated with high lethality rates among kidney transplant recipients (KTR), but also with a severe disruption and delays in overall healthcare, this study aims to evaluate the excess mortality in the pandemic era among KTR in a high-volume Brazilian transplant center.

METHODS

This study used data from a single center that provides follow-up on all its transplant recipients. The population of interest included all the patients who were transplanted between August 31, 1983 and December 31, 2022 and who were live from January 1, 2014. Using the "AutoRegressive Integrated Moving Average" forecasting algorithm, the expected mortality for the pandemic era (2020-2022) was modeled from the pre-pandemic era (2014-2019).

RESULTS

There were 12 077 KTRs at risk of dying in the entire observation period. In the pre-pandemic era, there were 21 deaths per 1000 patients at risk. In the pandemic era, there were 1429 observed deaths (rate of 47 deaths per 1000 patients at risk) versus the expected 587 deaths, resulting in an absolute number of 842 excess deaths, or an observed-to-expected ratio of 2.4, or an absolute rate of 26 deaths in excess per 1000 patients at risk. The excess deaths exhibited a temporal pattern mirroring that of the surges in new cases and lethality rates of COVID-19. COVID-19-related deaths drove 94% of excess mortality in the pandemic era.

CONCLUSION

In this large cohort of KTR under centralized follow-up, more than twofold excess mortality was primarily driven by COVID-19-related deaths, highlighting the vulnerability of this population to the most severe presentation of SARS-CoV-2 infection.

Humoral and cellular immunity against different SARS-CoV-2 variants in patients with chronic kidney disease

Chronic kidney disease (CKD) patients are at higher risk of severe COVID-19. Humoral and cellular immunity from prior infection or vaccination are important for protection, but the neutralizing antibody (nAb) response against SARS-CoV-2 variants is impaired. We investigated the variant-specific nAb and T cell immunity among CKD patients. Adult CKD patients were recruited between August and October 2022. nAb against the SARS-CoV-2 (ancestral strains and four Omicron sublineages) and T cell response were measured using the live virus neutralization assay and interferon-gamma release assay (IGRA). The correlation between nAb/T-cell response and subsequent infection after recruitment were also determined. Among the 88 recruited patients, 95.5% had prior infection or had completed the primary vaccine series. However, only 77.3% had detectable nAb against at least one SARS-CoV-2 strains, 59.1% tested positive in IGRA, and 52.3% had detectable nAb and tested positive in the IGRA. The nAb geometic mean titers (GMTs) against XBB.1, BA.5 and BA.2.3.20 were significantly lower than those against BA.2 and ancestral strain. Prior SARS-CoV-2 infection was associated with elevated nAb and T cell response. More kidney transplant recipients (KTRs) showed absent nAb and T cell response (36.8% vs. 10.1%), despite a higher prevalence of vaccine booster in this population (94.7% vs. 50.7%). Lower levels of nAb titer and T cell response were significantly associated with subsequent infection. A considerable proportion of CKD patients, especially KTRs, showed absence of humoral and cellular protective immunity against SARS-CoV-2. Strategies to improve immunogenicity in this population are urgently needed.

Understanding Concerns about COVID-19 and Vaccination: Perspectives from Kidney Transplant Recipients

The COVID-19 pandemic poses a significant risk for immunosuppressed groups such as transplant patients. The purpose of this study was to improve our understanding of the impact of the COVID-19 pandemic on kidney transplant recipients, including their views on COVID-19 vaccination. Semi-structured interviews were conducted from December 2021 to August 2022 with 38 kidney transplant recipients who had an appointment with their transplant care team within the previous 6 months. We used qualitative thematic analysis to characterize the perspectives of interviewees. Regardless of COVID-19 vaccination status, most interviewees reported utilizing public health measures such as masking, hand washing, and avoiding crowds to protect themselves against COVID-19. Vaccinated interviewees (n = 31) noted that they chose to receive a COVID-19 vaccine because of their increased risk due to their immunocompromised state. For unvaccinated interviewees (n = 7), reasons for not receiving a COVID-19 vaccine included concerns about the safety and efficacy of the vaccine. Both vaccinated and unvaccinated interviewees expressed concerns about the lack of adequate testing of the vaccine in transplant patients and questioned if the vaccine might have unknown side effects for transplant recipients. Regardless of the vaccination status, most interviewees noted having trust in their healthcare team. Interviewees also described interpersonal tensions that arose during the pandemic, many of which surrounded vaccination and other preventive measures that were important to participants to protect their health. Together, these data demonstrate differing concerns and experiences related to the COVID-19 pandemic for vaccinated and unvaccinated transplant recipients. These findings highlight the unique needs of transplant recipients and reveal opportunities to support this vulnerable patient population in efforts to protect their health as the COVID-19 pandemic evolves.