Differences in leucocytes and inflammation-based indices among critically ill patients owing to SARS-CoV-2 variants during several successive waves of COVID-19 pandemic

Awatef Ben Jemaa; Ridha Oueslati; Jihene Guissouma; Hatem Ghadhoune; Hana Ben Ali; Hend Allouche; Insaf Trabelsi; Mohamed Samet; Habib Brahmi

doi:10.1016/j.intimp.2023.110836

Differences in leucocytes and inflammation-based indices among critically ill patients owing to SARS-CoV-2 variants during several successive waves of COVID-19 pandemic

Int Immunopharmacol. 2023 Nov;124(Pt A):110836. doi: 10.1016/j.intimp.2023.110836. Epub 2023 Aug 24.

Authors

Awatef Ben Jemaa¹, Ridha Oueslati², Jihene Guissouma³, Hatem Ghadhoune³, Hana Ben Ali³, Hend Allouche³, Insaf Trabelsi³, Mohamed Samet³, Habib Brahmi³

Affiliations

¹ Unit IMEC-Immunology Microbiology Environmental and Carcinogenesis, Faculty of Science of Bizerte, Bizerte, Tunisia; Department of Biology, Faculty of Science of Gafsa, ,University of Gafsa, Gafsa, Tunisia. Electronic address: benjemaa_awatef@yahoo.fr.
² Unit IMEC-Immunology Microbiology Environmental and Carcinogenesis, Faculty of Science of Bizerte, Bizerte, Tunisia.
³ Intensive Care Department, CHU Habib Bougatpha Hospital, Bizerte, Tunisia; University of Tunis El Manar, Faculty of Medicine of Tunis, Tunis, Tunisia.

PMID: 37633238
DOI: 10.1016/j.intimp.2023.110836

Abstract

Background/aim: Inflammatory indices are useful informative markers in assessing the severity of the COVID-19 disease course; however, their involvements during series waves of SARS-CoV-2 virus outbreaks in critical patients with COVID-19 remain unclear. Hence, we aimed to ascertain the changing dynamics of the combined inflammatory indices (NLR, dNLR, CLR, LMR, PLR, SII, and SIRI) and their associations with clinical outcomes in severe COVID-19 patients during serial waves of SARS-CoV-2.

Patients and methods: We retrospectively enrolled 163 severe COVID-19 patients admitted to the ICU during six SARS-CoV-2 waves.

Results: We found that most of patients admitted to the ICU were from the fourth wave. Patients in the fourth wave were considerably younger and had the highest percentage of ARDS than other waves. The highest CRP was found in the first wave, while the lowest in patients admitted in the sixth wave. Although most of the COVID-19 waves were marked with leukocytosis, neutrophilia, and lymphocytopenia, the lowest of both NLR and dNLR were found in the fourth wave "Delta wave" and the lowest of both CLR and SII were observed in "Omicron wave". Interestingly, during most of the COVID-19 waves, the derived combined inflammatory ratio NLR, dNLR, CLR, SII and SIRI were sustained at high levels in fatal cases at the last day of hospitalization, while these indices declined in the alive group at the end of ICU hospitalization. No major difference was identified in lymphocyte count between admission and the last day of hospitalization in both deceased and recovered COVID-19 patients during Delta and Omicron waves. Moreover, patients admitted in the Omicron wave had less severe disease compared to those admitted in the Delta wave. The Kaplan-Meier analysis revealed no significant difference in survival rates or the probability of respiratory failure between six successive COVID-19 waves.

Conclusion: Taken together, our results showed marked differences in the alteration of nonspecific inflammation and damage in the adaptive immune response during the six serial SARS-CoV-2 waves. Considering the inflammatory response of infectious diseases, embedding inflammatory indices informative markers into routine clinical testing offers the potential to mitigate the impact of future pandemics of COVID-19 and other infectious diseases.

Keywords: COVID-19; Combined inflammatory indices; ICU; Immune cell subsets; SARS-CoV-2 Waves.