For transplant recipients, elevations of three biomarkers predict mortality from COVID-19
Among kidney transplant recipients in France, elevations of three specific biomarkers –including those showing inflammation, cardiac injury and thrombosis – were significantly associated with an increased risk for mortality due to COVID-19.
The study, which was published in Kidney International Reports, evaluated 494 individuals who were included in the French solid organ transplant COVID-19 registry during the first wave of the pandemic.
“Much of the recent focus in COVID-19 research has revolved around predictors of death and severe disease. Several studies in the adult general population have found an association between elevation of cardiac injury, coagulation, and inflammatory biomarkers and COVID19-related mortality,” Sophie Caillard, MD, PhD, of the department of nephrology and transplantation at Strasbourg University Hospital, and colleagues wrote. “Nevertheless, only a limited number of single-center studies specifically explored the clinical utility of circulating biomarkers for the prediction of COVID-19-related mortality in solid organ transplant recipients. By taking advantage of data from a French nationwide registry of [kidney transplant recipients] KTRs with COVID-19, we sought to investigate the prognostic significance of increased biomarkers of cardiac injury, coagulation and inflammation in this population.”
In the entire study population (411 participants were hospitalized and 83 were managed at home), SARS-CoV-2 infection was diagnosed a median of 6 years after transplant. For those hospitalized, the median interval between symptom onset and hospital admission was 5 days (the most common symptom was fever). The 60-day survival rate in the entire study cohort was 80%.
Caillard and colleagues assessed serum CRP and procalcitonin as markers of inflammation, circulating hs-troponin I as a marker for myocardial injury and D-dimer concentrations as a marker of thrombosis/coagulation.
Results pointed toward the predictive value of the biomarkers, with researchers finding patients with serum creatinine greater than 150 µmol/L, CRP greater than 50 mg/L, procalcitonin greater than 0.3 mg/L, hs-troponin I greater than 20 ng/L and D-dimer greater than 1,500 UI/L were at an increased risk of COVID-19-related mortality. Further, cumulative patient survival was significantly lower in those who had increased concentrations of these biomarkers at the time of hospital admission or diagnosis.
The combination of procalcitonin, D-dimer and hs-troponin I was “highly predictive” of mortality, with researchers observing the 60-day survival rate to be as high as 92% in patients without elevation of any of the three biomarkers; 60-day survival declined to 77% in those who had at least one elevated biomarker (and again to 58% with two elevated biomarkers and 40% with three).
“If independently validated, the use of biomarkers may help guiding therapeutic decision- making in transplant patients,” the researchers concluded of the findings.