Performance of Derived Laboratory Biomarkers with Regard to 30-Day Mortality in Kidney Transplant Recipients with COVID-19.

There are limited data on the performance of laboratory-derived biomarkers in kidney transplant recipients (KTR) with COVID-19. This observational study enrolled 65 KTR with COVID-19 who were treated at the University Hospital of Split up to March 2022. Laboratory-derived biomarkers (neutrophile-to-lymphocyte (NLR) ratio, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, De Ritis ratio, C-reactive protein (CRP)-to-albumin ratio, lactate dehydrogenase (LDH)-to-hemoglobin ratio, CRP-to-lymphocyte ratio, red cell distribution width-to-albumin ratio, platelet-to-albumin ratio, D-Dimer-to-albumin ratio, D-Dimer-to-NLR ratio, LDH-to-albumin ratio, and LDH-to-white blood cell (WBC) ratio) were calculated, and their performance with regard to 30-day mortality was determined. Mortality events occurred in 12 patients (18.5%), which was significantly associated with increased De Ritis (HR 3.83, 95% CI 1.57-9.35, p = 0.003), CRP-to-albumin (HR 1.36, 95% CI 1.13-1.64, p = 0.001), LDH-to-hemoglobin (HR 1.44, 95% CI 1.07-1.92, p = 0.015), CRP-to-lymphocyte (HR 1.03, 95% CI 1.01-1.07, p = 0.003), D-dimer-to-albumin (HR 4.94, 95% CI 1.38-7.24, p = 0.038), LDH-to-albumin (HR 1.20, 95% CI 1.05-1.36, p = 0.008), and LDH-to-WBC (HR 1.03 95% CI 1.01-1.05, p = 0.024) ratios. Out of these, the best area-under-the-curve (AUC) values were achieved with De Ritis (AUC 0.691), CRP-to-albumin (AUC 0.764), LDH-to-hemoglobin (AUC 0.877), CRP-to-lymphocyte (AUC 0.739), and LDH-to-albumin (AUC 0.827) ratios, while the best discrimination displayed LDH-to-hemoglobin ratio (Harrell's C 0.808 and Somers' D 0.616). The overall calibration was satisfactory for all models. Derived laboratory biomarkers such as the de Ritis, CRP-to-albumin, LDH-to-hemoglobin, CRP-to-lymphocyte, and LDH-to-albumin ratios show significant association and discrimination with all-cause mortality in KTR with COVID-19, suggesting its potential risk stratification role.

Association of the novel CROW-65 risk score and mortality in hospitalized kidney transplant recipients with COVID-19 : A retrospective observational study.

BACKGROUND: Kidney transplant recipients (KTR) are a group of patients with heterogeneous risks for adverse outcomes with COVID-19, but risk stratification tools in this patient group are lacking. METHODS AND PARTICIPANTS: This retrospective observational, hypothesis-generating study included 49 hospitalized adult KTR patients with COVID-19 at the University Hospital of Split (August 2020 to October 2021) and evaluated the performance of novel risk score CROW-65 (age, Charlson Comorbidity Index [CCI] lactate dehydrogenase to white blood cell [LDH:WBC] ratio, and respiratory rate oxygenation [ROX index]). The primary outcome of the study was 30-day postdischarge all-cause mortality. RESULTS: A total of 8 fatal events (16.3%) occurred during the study follow-up. When comparing CROW-65 by survival status, it was significantly increased in patients with fatal event (P < 0.001). Using the Cox proportional hazards regression analysis, the CROW-65 risk score showed statistically significant association with mortality (HR 1.11, 95% CI 1.01-1.23, P = 0.027), while receiving operator characteristics (ROC) showed significant discrimination of all-cause mortality with an AUC of 0.85 (95% CI 0.72-0.94, P < 0.001), and satisfactory calibration (χ2 4.91, P = 0.555 and Harrell's C 0.835). Finally, survival Kaplan-Meier analysis confirmed significantly higher cumulative incidence of mortality with increasing risk score tertiles and curve separation after 13 days (P = 0.009). CONCLUSION: A novel risk score CROW-65 showed significant association with all-cause mortality in KTR yielding important hypothesis-generating findings. Further powered studies should reassess the performance of CROW-65 risk score in this population, including predictability, calibration and discrimination.