The critical role of complete blood count in the management of patients with COVID-19

The critical role of complete blood count in the management of patients with COVID-19

Maryame Ahnach^1,&, Nouama Bouanani¹, Sara Nejjari¹, Mounia Bendari¹, Kamal Doghmi², Chafik El kettani³

¹Department of Hematology, Cheikh khalifa International University Hospital, Mohammed VI University of Health Sciences Casablanca, Morocco, ²Department of Hematology, Military Hospital Mohammed V, Mohammed V University Faculty of medicine and Pharmacy, Rabat, Morocco, ³Department of Anesthesiology and Reanimation, Cheikh khalifa International University Hospital, Hassan II VI University Faculty of Medicine and Pharmacy, Casablanca, Morocco

^&Corresponding author
Maryame Ahnach, Department of Hematology, Cheikh khalifa International University Hospital, Mohammed VI University of Health Sciences Casablanca, Morocco

To the editors of the Pan African Medical Journal    

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 30 10⁹/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 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.

Competing interests    

All authors declare no competing interests.

Authors' contributions     

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.

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