Coronavirus Disease 2019 in Kidney Transplant Recipients: Single-Center Experience and Case-Control Study

Clinical outcome in solid organ transplant recipients affected by COVID-19 compared to general population: a systematic review and meta-analysis

BACKGROUND

A significant increased risk of complications and mortality in immunocompromised patients affected by COVID-19 has been described. However, the impact of COVID-19 in solid organ transplant (SOT) recipients is an issue still under debate, due to conflicting evidence that has emerged from different observational studies.

OBJECTIVES

We performed a systematic review with a meta-analysis to assess the clinical outcome in SOT recipients with COVID-19 compared with the general population.

DATA SOURCES

PubMed-MEDLINE and Scopus were independently searched until 13 October 2021.

STUDY ELIGIBILITY CRITERIA

Prospective or retrospective observational studies comparing clinical outcome in SOT recipients versus general populations affected by COVID-19 were included. The primary endpoint was 30-day mortality.

PARTICIPANTS

Participants were patients with confirmed COVID-19.

INTERVENTIONS

Interventions reviewed were SOTs.

METHODS

The quality of the included studies was independently assessed with the Risk of Bias in Non-randomized Studies of Interventions tool for observational studies. The meta-analysis was performed by pooling ORs retrieved from studies providing adjustment for confounders using a random-effects model with the inverse variance method. Multiple subgroups and sensitivity analyses were conducted to investigate the source of heterogeneity.

RESULTS

A total of 3501 articles were screened, and 31 observational studies (N = 590 375; 5759 SOT recipients vs. 584 616 general population) were included in the meta-analyses. No difference in 30-day mortality rate was found in the primary analysis, including studies providing adjustment for confounders (N = 17; 3752 SOT recipients vs. 159 745 general population; OR: 1.13; 95% CI, 0.94-1.35; I2 = 33.9%). No evidence of publication bias was reported. A higher risk of intensive care unit admission (OR: 1.56; 95% CI, 1.03-2.63) and occurrence of acute kidney injury (OR: 2.50; 95% CI, 1.81-3.45) was found in SOT recipients.

CONCLUSIONS

No increased risk in mortality was found in SOT recipients affected by COVID-19 compared with the general population when adjusted for demographic and clinical features and COVID-19 severity.

Increased Tacrolimus Exposure in Kidney Transplant Recipients With COVID-19: Inflammation-Driven Downregulation of Metabolism as a Potential Mechanism

Kidney transplant recipients (KTRs) are at increased risk of severe COVID-19 disease compared to the general population. This is partly driven by their use of immunosuppressive therapy, which influences inflammatory responses and viral loads. Current guidelines suggest to withdraw mycophenolate while calcineurin inhibitors are often continued during a COVID-19 infection. However, clinical signs of calcineurin toxicity have been described in multiple COVID-19 positive KTRs. In this report we describe the course of tacrolimus exposure prior to, during, and post COVID-19 in observations from three clinical cases as well as four KTRs from a controlled trial population. We postulate inflammation driven downregulation of the CYP3A metabolism as a potential mechanism for higher tacrolimus exposure. To mitigate the risk of tacrolimus overexposure and toxicity therapeutic drug monitoring is recommended in KTRs with COVID-19 both in the in-, out-patient and home monitoring setting.

Elevated Tacrolimus Levels at Time of Diagnosis of COVID-19 Compared to Baseline Among Hospitalized Organ Transplant Recipients

BACKGROUND

The effect of COVID-19 on immunosuppressant drug levels in organ transplant recipients (OTRs) has not been adequately studied.

OBJECTIVE

To study the effect of COVID-19 on tacrolimus trough levels (primary outcome) in OTRs and the association of the later with acute kidney injury, bacterial infection, and oxygen requirements.

METHODS

We studied adult (>18-year-old) hospitalized OTRs with COVID-19, who were receiving tacrolimus between 3/1 and 12/16/2020.

RESULTS

Among 30 OTRs, 67% were men, 90% had a kidney transplant. Median age was 60.5 (interquartile range [IQR]: 45-68) years, median time from transplant 36 (IQR: 20-84) months. Tacrolimus troughs were higher on admission for COVID-19 than baseline (average over 6 months prior) (P = .001). Eighteen patients (60%) had admission tacrolimus trough >10, 5 (17%) >20 ng/mL. Patients with diarrhea had borderline higher tacrolimus troughs, compared to those without diarrhea (P = .09). Organ transplant recipients with a tacrolimus trough >10 ng/mL were more likely to have elevated aspartate aminotransferase on admission (P = .01) and require supplemental oxygen. (P = .026).

CONCLUSION AND RELEVANCE

Tacrolimus trough levels were elevated in most OTRs with COVID-19 at the time of hospital admission, compared to baseline. Potential mechanisms are diarrhea and hepatic involvement in COVID-19. In OTRs with COVID-19, including outpatients, immunosuppressant drug levels should be closely followed; management of immunosuppression should be individualized.

Use of anti-spike monoclonal antibodies in kidney transplant recipients with COVID-19: Efficacy, ethnic and racial disparities

Organ transplant recipients may not mount an adequate immune response to COVID-19 infection and therefore may benefit greatly from passive immunization with anti-spike monoclonal antibodies (mAbs), which have been shown to decrease hospitalization rates in the general outpatient population. We evaluated the efficacy of mAb therapy in decreasing hospitalizations or emergency room (ER) visits among kidney transplant recipients (KTR) with COVID-19. We identified KTR with COVID-19 between March 1, 2020 and April 30, 2021. Patients were excluded if they had multi-organ transplant or hospital-acquired COVID-19. We studied 95 KTR; 20 received mAb. mAb administration was associated with a significant decrease in hospitalizations or ER visits (15% vs. 76%, p < 0.001). This association remained significant after adjustment for potential confounders, and analysis of mAb administration as a time-dependent variable, with day of symptom onset as day 1 (adjusted HR 0.216, p = 0.04). Black or Hispanic patients were less likely to receive mAb and more likely to be admitted to the hospital or visit the ER. In our KTR population, mAb therapy for COVID-19 may have helped decrease hospitalizations and ER visits. Healthcare inequities, including access to investigational treatments, have been exacerbated by the COVID-19 pandemic. Antiviral mAbs are a promising therapeutic modality, especially for immunocompromised patients.

Incidence of Mortality, Acute Kidney Injury and Graft Loss in Adult Kidney Transplant Recipients with Coronavirus Disease 2019: Systematic Review and Meta-Analysis

The adverse impact of Coronavirus disease 2019 (COVID-19) on kidney function has been reported since the global pandemic. The burden of COVID-19 on kidney transplant recipients, however, has not been systematically analyzed. A systematic review and meta-analysis with a random-effect model was conducted to explore the rate of mortality, intensive care unit admission, invasive mechanical ventilation, acute kidney injury, kidney replacement therapy and graft loss in the adult kidney transplant population with COVID-19. Sensitivity analysis, subgroup analysis and meta-regression were also performed. Results: we demonstrated a pooled mortality rate of 21% (95% CI: 19−23%), an intensive care unit admission rate of 26% (95% CI: 22–31%), an invasive ventilation rate among those who required intensive care unit care of 72% (95% CI: 62–81%), an acute kidney injury rate of 44% (95% CI: 39–49%), a kidney replacement therapy rate of 12% (95% CI: 9–15%), and a graft loss rate of 8% (95% CI: 5–15%) in kidney transplant recipients with COVID-19. The meta-regression indicated that advancing age is associated with higher mortality; every increase in age by 10 years was associated with an increased mortality rate of 3.7%. Regional differences in outcome were also detected. Further studies focused on treatments and risk factor identification are needed.