Characterization and trajectories of hematological parameters prior to severe COVID-19 based on a large-scale prospective health checkup cohort in western China: a longitudinal study of 13-year follow-up

• Published in: BMC medicine Vol. 22; no. 1; pp. 105 - 16
• Main Authors: Lin, Yifei, Yang, Yong, Xiang, Nanyan, Wang, Le, Zheng, Tao, Zhuo, Xuejun, Shi, Rui, Su, Xiaoyi, Liu, Yan, Liao, Ga, Du, Liang, Huang, Jin
• Format: Journal Article
• Language: English
• Published: London BioMed Central 07.03.2024; BioMed Central Ltd; BMC
• Subjects: Acids; Big Data; Biomedicine; Blood; Blood cell count; Blood platelets; Body mass index; CD4 antigen; CD8 antigen; Cell number; COVID-19; COVID-19 - diagnosis; COVID-19 - epidemiology; Diabetes; Epidemics; Epidemiology; Erythrocytes; Flow cytometry; Follow-Up Studies; Gene mutations; Health aspects; Health care facilities; Health checkup; Health risks; Hematology; Hemoglobin; Hospitals; Humans; Hypertension; Infections; Intensive care; Laboratories; Leukocytes; Leukocytes (basophilic); Leukocytes (neutrophilic); Long COVID; Long term; Longitudinal Studies; Lymphocytes; Medicine; Medicine & Public Health; Monocytes; Neutrophils; Outbreaks; Parameter identification; Post-Acute COVID-19 Syndrome; Proactive health; Prospective cohort; Public health; Research Article; Retrospective Studies; Risk; Risk groups; SARS-CoV-2; Sensitivity analysis; Severe acute respiratory syndrome coronavirus 2; Viral diseases; China; COVID-19; Health checkup; Proactive health; Long term; Prospective cohort
• ISSN: 1741-7015; 1741-7015
• DOI: 10.1186/s12916-024-03326-x

Background The relaxation of the “zero-COVID” policy on Dec. 7, 2022, in China posed a major public health threat recently. Complete blood count test was discovered to have complicated relationships with COVID-19 after the infection, while very few studies could track long-term monitoring of the health status and identify the characterization of hematological parameters prior to COVID-19. Methods Based on a 13-year longitudinal prospective health checkup cohort of ~ 480,000 participants in West China Hospital, the largest medical center in western China, we documented 998 participants with a laboratory-confirmed diagnosis of COVID-19 during the 1 month after the policy. We performed a time-to-event analysis to explore the associations of severe COVID-19 patients diagnosed, with 34 different hematological parameters at the baseline level prior to COVID-19, including the whole and the subtypes of white and red blood cells. Results A total of 998 participants with a positive SARS-CoV-2 test were documented in the cohort, 42 of which were severe cases. For white blood cell-related parameters, a higher level of basophil percentage (HR = 6.164, 95% CI = 2.066–18.393, P  = 0.001) and monocyte percentage (HR = 1.283, 95% CI = 1.046–1.573, P  = 0.017) were found associated with the severe COVID-19. For lymphocyte-related parameters, a lower level of lymphocyte count (HR = 0.571, 95% CI = 0.341–0.955, P  = 0.033), and a higher CD4/CD8 ratio (HR = 2.473, 95% CI = 1.009–6.059, P  = 0.048) were found related to the risk of severe COVID-19. We also observed that abnormality of red cell distribution width (RDW), mean corpuscular hemoglobin concentration (MCHC), and hemoglobin might also be involved in the development of severe COVID-19. The different trajectory patterns of RDW-SD and white blood cell count, including lymphocyte and neutrophil, prior to the infection were also discovered to have significant associations with the risk of severe COVID-19 (all P  < 0.05). Conclusions Our findings might help decision-makers and clinicians to classify different risk groups of population due to outbreaks including COVID-19. They could not only optimize the allocation of medical resources, but also help them be more proactive instead of reactive to long COVID-19 or even other outbreaks in the future.