key: cord-0860259-121slr0f
authors: Ahnach, Maryame; Bouanani, Nouama; Nejjari, Sara; Bendari, Mounia; Doghmi, Kamal; El kettani, Chafik
title: The critical role of complete blood count in the management of patients with COVID-19
date: 2020-06-04
journal: Pan Afr Med J
DOI: 10.11604/pamj.supp.2020.35.2.23764
sha: 9ad7714da428cf69c4a9ec7dbc4c44262e894c7d
doc_id: 860259
cord_uid: 121slr0f

nan

Since March 2020, the world has declared a global health crisis caused by the coronavirus COVID-19 pandemic. After Asia, Europe, the United States is the most affected. The main features described are pulmonary manifestations, however, this systemic infection seems to have a direct impact on the hematopoietic system. Many publications have documented the clinical, biological and radiological characteristics of COVID-19 infection, and several international societies have developed protocols for management and follow-up. In these recommendations, biological analysis and especially the complete blood count, represents a major tool in the diagnosis, monitoring, detection of severe forms, and hematological complications [1] . Quantitative hematologic abnormalities have been reported since the first papers, all blood cells can be affected during COVID-19, mainly leukocyte and platelet cells [2] .

During asymptomatic forms or the incubation period, patients can manifest a moderate abnormality in the blood count, Qilin et al suggested the potential value of eosinopenia as predictors of early identification of COVID-19 [3] . Regarding symptomatic forms, Guan et al found in a large series of 1099 cases, a predominance of lymphopenia (83%), thrombocytopenia (36.2) and neutropenia (33.7%) [4] . In severe cases, these abnormalities were more prominent (96.1% versus 80.4% lymphopenia, 57.7% versus 31.6% thrombocytopenia and 61.1% versus 28.1% for leukopenia) [5] . Lymphopenia is the most common sign, in fact, the coronavirus attack directly and indirectly the lymphocytes by immune and inflammatory mechanisms [6] . The analysis of the lymphocyte count is therefore a reliable indicator of the severity, which can be really useful in the monitoring and therapeutic adaptation, moreover after clinical improvement the lymphocyte count is corrected [7] .

Among recent studies, a meta-analysis, have reported the association between low platelet count (less than 30 10 9 /l) and the increased risk of severity and mortality from COVID-19. The pathophysiologic mechanism of thrombocytopenia is multifactorial due mainly to disseminated intravascular coagulation, micro-vascular thrombosis and macrophagic activation syndromes, that can cause bleeding and poor outcome [8] . In summary, the blood count as a routine biological analysis, keeps a prominent role in the early diagnosis and follow-up of COVID-19 infection. The blood cells perturbations are seen as a prognosis factors, careful analysis and interpretation of lymphocyte and platelet count, allows not only to evaluate the prognosis, but above a clinician to adapt

Laboratory abnormalities in patients with COVID-19 infection

Hematologic parameters in patients with COVID-19 infection

A simple laboratory parameter facilitates early identification of COVID-19 patients

Jian-Xing He et al. Clinical Characteristics of Coronavirus Disease 2019 in China

Hematological findings and complications of COVID-19

Lymphopenia predicts disease severity of COVID-19: a descriptive and predictive study

Characteristics of peripheral lymphocytes subset alteration in COVID-19 pneumonia

Thrombocytopenia is associated with severe coronavirus disease 2019 (COVID-19) infections: A metaanalysis

therapeutic care. Compared to specific inflammatory biomarkers tests (Lactate dehydrogenase, Interleukin, procalcitonin, etc.), the blood count remains a less expensive alternative, especially in countries with limited resources.

All authors declare no competing interests.

Maryame Ahnach conceptualized and write the manuscript. Nouama Bouanani, Mounia Bendari , Kamal Doghmi and Chafik El kettani collect data. All authors have read and approved the final version of manuscript.