Hemograms and serial hemogram-derived ratios in survivors and non-survivors of COVID-19 in Campinas, Brazil

Abstract

Introduction: The hemogram and hemogram-derivative ratios (HDRs) are becoming markers of the severity and mortality of COVID-19. We evaluated the hemograms and serial weekly HDRs [neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), neutrophil-platelet ratio (NPR) and systemic immune-inflammatory index (SII)] in the survivors and non-survivors of COVID-19.

Methods: We retrospectively reviewed the medical notes and serial hemograms of real-time reverse-transcription polymerase chain reaction (RT-PCR)-confirmed COVID-19 adults hospitalized from April 2020 to March 2021 from the time of diagnosis to the 3^rd week of diagnosis.

Results: Of the 320 adults, 257 (80.3%) were survivors and had a lower mean age than the non-survivors (57.73 vs. 64.65 years, p < 0.001). At diagnosis, the non-survivors had lower hematocrit (p = 0.021), and lymphocyte (p = 0.002) and basophil (p = 0.049) counts and the hematocrit showed a p-value (Is this what you meant???) of 0.021); higher NLR (p < 0.001), PLR (p = 0.047), NPR (p = 0.022) and SII (p = 0.022). Using general linear models, the survivors and non-survivors showed significant variations with weekly lymphocyte count (p < 0.001), neutrophil count (p = 0.005), NLR (p = 0.009), MLR (p = 0.010) and PLR (p = 0.035). All HDRs remained higher in the non-survivors in the 2^nd week and 3^rd week of diagnosis and the HDRs were higher in the intubated patients than in the non-intubated patients. The NLR and SII were more efficient predictors of mortality in COVID-19 patients.

Conclusions: This study shows that serial lymphocyte and neutrophil counts, NLR, PLR, MLR, NPR and SII could serve as good and easily accessible markers of severity and predictors of outcomes in COVID-19 patients and should be used for the monitoring of treatment response.

Keywords: COVID-19; Complete blood counts; Disease outcome; Inflammation; Survivors.

Figure 1

Multivariate Analysis of the Hemogram-Derived Ratios between COVID-19 Survivors and Non-Survivors: A. Neutrophil-Lymphocyte Ratio (NLR); B. Platelet-Lymphocyte Ratio (PLR); C. Monocyte-Lymphocyte Ratio; D. Neutrophil-Platelet Ratio (NPR); E. Systemic Immune Inflammation Index (SII) at diagnosis (W0), 2^nd week (W1), and 3^rd week (W2) post-diagnosis, ns not significant, * p < 0.05, ** p < 0.01, ***p < 0.001 (Mann-Whitney test). n = 174 (134 survivors and 40 non-survivors).