Dynamic profile and clinical implications of hematological and immunological parameters in COVID-19 patients. A retrospective study.

Background: Ever since the World Health Organization (WHO) announced the SARS-CoV-2 or nCOVID-19 infection (a pandemic), continuous spread of the virus has been observed which has continuously seen to affect and kill multitudes of individuals all over the world. An understanding of the pathophysiology of this disease is necessary for an effective treatment. Laboratory investigations play an important role in the diagnosis as well as treatment of this infectious disease. Hematological parameters demonstrate alterations during the progression of nCOVID-19 infection. Of these, many are indicative of extremely poor clinical outcome. Hematological findings like leukopenia, lymphopenia, thrombocytopenia and coagulation-related abnormalities are the most common manifestations. The aim of this study was to assess the dynamic profile and clinical implications of hematological and immunological parameters among nCOVID-19 infections. Materials and Methods: This retrospective study was designed after categorizing patients suffering from COVID-19 into three groups: (a) Group I; (b) Group II and (c) Group III or severe critical patients. Hematological and immunological parameters of neutrophilic and white blood cell counts, d-dimer levels, hemoglobin levels, immunoglobulin G (IgG) and M (IgM) levels and interleukin-6 (IL-6) levels were assessed. Statistical analysis using Kruskal–Wallis test was used. Results: Normal white blood cell and neutrophil count among COVID-19 patients was seen. However, median values in Group II (P < 0.01) and Group III (P < 0.0001) were found to show significantly higher values when compared to Group I. A significant (P < 0.01) decrease in lymphocytic counts was found among severe and critical patients. Hemoglobin level was found to demonstrate higher decrease (P < 0.01) among severe and critical patients. Platelet count was found in normal range in all COVID-19 patients. Routine coagulation tests revealed increased fibrinogen (P < 0.01) and d-dimer levels (P < 0.0001) in severe and critical patients. Normal proportions of total CD3+ and CD4 + T lymphocytes were observed in COVID-19. However, CD8 + T lymphocytes proportion was found to be decreased (P-value < 0.05). Immunoglobulin G levels among Groups II and III patients were found to be lower when compared with Group I (P < 0.001). No statistical significance was observed between the groups in IgM levels. Plasma IL-6 levels were found to show progressive rise among Groups II and III patients (P < 0.05). Conclusion: Analysis of hematological and immunological parameters profiles in COVID-19 patients may help in deciphering the clinical progression of patients suffering from COVID-19 disease. Thus, regular monitoring of the hospitalized patients may help in planning the management of these cases. [ABSTRACT FROM AUTHOR]