A Retrospective Observational Study: Is Absolute Lymphocyte Count a Prognostic Marker in COVID-19?

Mansoor Zafar,Alisha Khanna,Mangala Karkhanis,Ubaid Ur Rehman,Stefano Berliti,Steve Moran,Bipin Pun,Karuna Subba,Saba Alam,Ellie M Giddings,Lucinda Barry,Muhammad Shahbaz,Kamal Lawrence,Mohamed Abdelbagi,Najam-Us-Saher Rizvi,Jabeen Hsiao,Johannes Hegner,Reem Eldebri,Tila Muhammad,Amr Elyasaky,Bao Khuu,Umesh Dashora,Athanasios Nakos,Nadiyah Zafar,Manivannan Periasamy,Gjulio Ciroi,Simon Merritt,Viktoriya Clarke,Mirej Patel,Bianca A Lazau,Mariya Farooq,Maryam Zare ,Maaryah J Zafar ,Frederic Cuison ,O A Makanjuola ,Oluwamayowa Ojofeitimi ,M Whitehead ,Dana Šafářová ,B A Adekunle ,Hesam Ahmadi Nooredinvand ,Osei Kankam ,Ratan Randhawa ,Andreia Esteves Morete ,William A O'neill

doi:10.7759/cureus.16554

Abstract

AimOur study aimed to find a correlation between low absolute lymphocyte count and COVID-19-related mortality.MethodsThis study followed a retrospective observational cohort design to analyze the data of patients who presented with symptoms and signs of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), at the Conquest Hospital and Eastbourne District General Hospital in East Sussex, United Kingdom, between February 10, 2020 and May 1, 2020, retrospectively. Survival and mortality for the first 30 days and comorbidities were analyzed for all patients who were tested for COVID-19 irrespective of swab results and had blood lymphocyte levels taken at the time of their visit to the ED and their data were analyzed for statistical significance.ResultsA total of 1226 patients had SARS-CoV-2 RNA identification swabs taken between February 10, 2020 and May 1, 2020. A cohort of 742 patients of these patients tested for COVID-19 also had blood lymphocyte levels measured.Overall, the lymphocyte count did not differ significantly between patients suspected to have COVID-19 infection with either positive or negative COVID-19 swab results.The lymphocyte count, however, was significantly lower in those who died from COVID-19 (p < 0.001) but when comorbidities were analyzed, we found an association between an increased number of comorbidities and a significantly decreased lymphocyte count.ConclusionOnce adjusted for comorbidities, the lymphocyte count had no association with COVID-19 infection and mortality.

Highlights

The 21st century has witnessed a global pandemic of the COVID-19 phenomenon, that has wreaked havoc worldwide issuing lockdowns, panic, and disaster
Our study aimed to find a correlation between low absolute lymphocyte count and COVID-19-related mortality
Survival and mortality for the first 30 days and comorbidities were analyzed for all patients who were tested for COVID-19 irrespective of swab results and had blood lymphocyte levels taken at the time of their visit to the ED and their data were analyzed for statistical significance

Summary

Introduction

The 21st century has witnessed a global pandemic of the COVID-19 phenomenon, that has wreaked havoc worldwide issuing lockdowns, panic, and disaster. It is an illness that mainly affects the respiratory system and is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Information about the prognostic markers is limited. Lymphopenia is defined as a lymphocyte count level less than 1.5 x10^9/l, and several studies suggest an association of COVID-19 with lymphopenia [1,2]. Other studies have focused on lymphocyte count mainly in the ICU during acute admission [3]. There is minimal information available about the level of lymphopenia or lymphocyte count that is strongly associated with increased mortality due to COVID-19. The role of comorbidity and other confounding variables is not clear [4]

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