A Retrospective Study of Absolute Lymphocyte Count as a Marker of Covid 19 Disease Severity in Tertiary Care Center

Abstract

Introduction: Coronavirus disease 2019 (Covid‐19) is a predominantly respiratory illness caused by the SARS‐CoV‐2 virus. Data regarding prognostic factors are currently scarce given the novelty of the disease. Prognostic information would aid clinicians in managing patients, who are often left without data‐driven guidelines to make important clinical decisions. It is known that lymphocytopenia, defined as an absolute lymphocyte count (ALC) < 1000 cells/μL, occurs in Covid‐19 and may correlate with increased disease severity.Materials and Methods: Data were obtained for patients admitted to one local, academic, community‐based Hazaribag Medical College and hospital, Hazaribag. Patients were included if they had a positive diagnosis of Covid‐19 based on a polymerase chain reaction‐based assay to detect the SARS‐CoV‐2 virus or had been diagnosed in the community, were over the age of 18, and were admitted and discharged from the hospital between 03/01/2020 and 30/07/2020. Results: We obtained 114 patients who were admitted to and discharged from the hospital between 03/01/2020 and 30/07/2020. The cohort was predominantly male (59%), obese (average BMI of 32.3 ± 1.19 kg/m2) with an average age of 58.2 ± 2.08 years. Our cohort consisted mostly of patients with minority backgrounds (86%). Thirty‐one percent of patients (N = 36) were admitted to the ICU and mortality was 16% (N = 18). Of note, 4 patients had a diagnosis of Human Immunodeficiency Virus (HIV) infection. The median Charlson comorbidity index was 4 (1.5‐6), indicating an median 10‐year survival rate of 53%. In our study, we found that 50% (18/36) of patients admitted to the ICU required intubation and 38% (14/36) required vasopressors. Thus, patients admitted to the ICU were classified as having severe disease given the relatively common occurrence of hemodynamic instability and respiratory failure in this population.Conclusion: In summary, we find that lymphocytopenia and anemia are more common in patients admitted to the ICU, with an odds ratio of approximately 3.4 and 3.6, respectively. Additionally, patients with lymphocytopenia are more likely to develop an AKI relative to those without lymphocytopenia by an odds ratio of 4.2. Thus, it appears likely that lymphocytopenia is related to disease severity and clinical outcomes in Covid‐19.