Hematology, immunology and clinical chemistry profiles of COVID-19 patients: Systematic review

Abstract

Background: COVID-19 is an emerging novel viral infection that first emerged in December 2019 and was officially pronounced as a ‘pandemic’ by March 2020. One of the strategies to control the spread of COVID-19 disease is expanding laboratory diagnosis services. So far, the molecular biology-based real-time polymerase chain reaction (RT-PCR) method is the only recommended laboratory test to diagnose the disease. However, during COVID-19 infection, hematology, immunology, and clinical chemistry test profile changes might also assist in diagnosing the disease.

Objective: The objective of this systematic review was “assessment of routine hematology, immunology, and clinical chemistry test profile changes among COVID-19 RT-PCR laboratory tests positive individuals”, which, before such tests are carried out, might suggest the occurrence of COVID-19 infection.

Material and methods: The systematic review was done to assess general epidemiology, routine clinical chemistry and hematology/ immunohematology tests done in association with COVID-19 diagnosed cases. Online published articles were searched using PubMed, Hinari, AGORA and Google Scholar search engines, based on the following inclusion criteria: articles on COVID-19 that focus on human coronavirus diseases, their epidemiology, laboratory diagnosis of such diseases, the RT-PCR test, and additional routine laboratory tests. Exclusion criteria included articles that discuss the RT-PCR method only, imaging diagnostic methods, and those that focus on specific groups (such as COVID-19 among diabetes patients, cancer patients and so on). Accordingly, a total of 75 research articles were identified. Of these, 29 papers were selected for systematic review.

Results: From the collected 29 articles on routine clinical chemistry tests, it was concluded that in confirmed COVID-19 cases, aminotransferase enzymes – alanine transaminase (ALT) and aspartate transaminase (AST) – bilirubin, creatine kinase (CK), troponin, lactate dehydrogenase (LDH), creatine  and ferritin values were relatively high, whereas the albumin value was reduced. In the hematology/immunohematology tests, total white blood cell (WBC) counts, neutrophil counts, erythrocyte sedimentation rates (ESR), C-reactive protein (CRP) and prothrombin time (PT) increased, whereas lymphocyte counts, platelet counts, and cluster of differentiation 4 (CD4) and cluster of differentiation 8 (CD8) counts decreased. In addition, neutrophil-lymphocyte (N-L) ratios increased, whereas lymphocyte-C-reactive protein (L-C) ratios decreased.

Conclusions: For those individuals with signs and symptoms of COVID-19, leukocytosis with neutrophilia and lymphopenia, high N-L and low L-C ratios, mild increases in aminotransferase and creatinine values with increased CK, troponin and ferritin levels, might be considered as “routine laboratory test results that are supportive of occurrence COVID-19 disease”. Further large-scale studies are required to strengthen the present findings. [Ethiop. J. Health Dev. 2020; 34(3):226-231]

Key words: COVID-19, clinical chemistry, hematology, immunohematology tests