Context: Inflammation is a significant factor driving the rise of multiple cases of viral pneumonia, including COVID-19 infection. Peripheral white blood cells (WBCs), the neutrophil (NEU)-to-lymphocyte (LYM) ratio (NLR), the platelet-to-lymphocyte (PLR) ratio, and hemoglobin (Hb) are markers of systematic inflammatory reaction and often predict disease severity.
Objective: The current study intended to examine the prognostic importance of hemoglobin (Hb), total leukocyte count (TLC), absolute neutrophile count (ANC), absolute lymphocyte count (ALC), NLR, d-NLR [derived NLR = ANC/(WBC-ANC)], absolute platelet count (APC), and PLR, based on complete blood counts (CBCs) for COVID-19 patients.
Design: The research team designed a retrospective that was conducted between March 27 and June 5, 2020, after the first COVID-19 case was reported in Ajmer, Rajasthan, India on March 27.
Setting: The study took place at Jawaharlal Nehru (JLN) Medical College in Ajmer, Rajasthan, India.
Participants: The study included 364 participants who were all COVID-positive patients who came to the hospital during the study's period, including patients from various age groups and of both genders.
Outcome measures: Using the results of the CBC, the research team measured: (1) Hb in g/dl, (2) ANC, (3) ALC, and (4) APC. The neutrophil-lymphocyte ratio (NLR) and the platelet-lymphocyte ratio (PLR) were calculated from measurements of the levels of the circulating biomarkers, as cells × 103/μl.
Result: For participants who were severely symptomatic, the mean age was 57.86 ± 8.92. Males were more likely to experience severe symptoms. Participants' Hb values were significantly different between groups, and TLC, ANC, NLR, d-NLR, and PLR were highest in the severely symptomatic group and lowest in the asymptomatic group. NLR was positively associated with a risk of COVID-19 pneumonia, while Hb was negatively associated with development of pneumonia.
Conclusions: Disease severity and age are independent predictors of poor outcomes. The NLR should be used as a routine blood test that can help in the diagnosis of disease severity in COVID-19. NLR is very simple tool that can be used as a fast and low-cost test that is easily available, even in small centers where the facilities for other tests, such as tests of LDH, CRP, and IL-6, and high resolution CT scans aren't available. Thus, NLR can be used as single independent predictor of COVID-19 disease severity.