Clinical course and predictive risk factors for fatal outcome of SARS-CoV-2 infection in patients with chronic kidney disease

Abstract

Purpose: The ongoing pandemic caused by the novel severe acute respiratory coronavirus 2 (SARS-CoV-2) has stressed health systems worldwide. Patients with chronic kidney disease (CKD) seem to be more prone to a severe course of coronavirus disease (COVID-19) due to comorbidities and an altered immune system. The study's aim was to identify factors predicting mortality among SARS-CoV-2-infected patients with CKD.

Methods: We analyzed 2817 SARS-CoV-2-infected patients enrolled in the Lean European Open Survey on SARS-CoV-2-infected patients and identified 426 patients with pre-existing CKD. Group comparisons were performed via Chi-squared test. Using univariate and multivariable logistic regression, predictive factors for mortality were identified.

Results: Comparative analyses to patients without CKD revealed a higher mortality (140/426, 32.9% versus 354/2391, 14.8%). Higher age could be confirmed as a demographic predictor for mortality in CKD patients (> 85 years compared to 15-65 years, adjusted odds ratio (aOR) 6.49, 95% CI 1.27-33.20, p = 0.025). We further identified markedly elevated lactate dehydrogenase (> 2 × upper limit of normal, aOR 23.21, 95% CI 3.66-147.11, p < 0.001), thrombocytopenia (< 120,000/µl, aOR 11.66, 95% CI 2.49-54.70, p = 0.002), anemia (Hb < 10 g/dl, aOR 3.21, 95% CI 1.17-8.82, p = 0.024), and C-reactive protein (≥ 30 mg/l, aOR 3.44, 95% CI 1.13-10.45, p = 0.029) as predictors, while renal replacement therapy was not related to mortality (aOR 1.15, 95% CI 0.68-1.93, p = 0.611).

Conclusion: The identified predictors include routinely measured and universally available parameters. Their assessment might facilitate risk stratification in this highly vulnerable cohort as early as at initial medical evaluation for SARS-CoV-2.

Keywords: COVID-19; Chronic kidney disease; LEOSS; Predictive factor; SARS-CoV-2.

Fig. 1

LEOSS definition of clinical phases (https://leoss.net/statistics/). ALT alanine transaminase, AST aspartate aminotransferase, INR international normalized ratio, SO₂ oxygen saturation, ULN upper limit of normal in the respective local laboratory

Fig. 2

Forest plot of predictive factors for fatal outcome in SARS-CoV-2-infected patients suffering from chronic kidney disease. Continuous parameters were collected in categories. n = 289 observations were excluded from multivariable regression model due to missingness. Missing rates and frequency distribution are displayed in Suppl. Table 2 for variables with missing rate > 5%. Reference categories: CRP < 30 mg/l, hemoglobin ≥ 10 g/dl, platelets ≥ 120,000/µl, lymphocytes ≥ 800/µl, LDH normal, no dyspnea, SO2 ≥ 90%, no immunosuppressive medication, not on dialysis, no cerebrovascular disease, no atrial fibrillation, no chronic heart failure, age 15–65 years. CRP C-reactive protein, SO₂ oxygen saturation in arterial blood, LDH lactate dehydrogenase, ULN upper limit of normal in the respective local laboratory