Rakesh Holla A*
Department of Pathology, 160 Military Hospital, Assam, India
*Corresponding Author: Rakesh Holla A, Department of Pathology, 160 Military Hospital, Assam, India.
Received: July 25, 2021; Published: September 18, 2021
The pandemic Covid-19 is caused by a single stranded RNA virus, SARS-CoV2 (Severe Acute Respiratory Syndrome Coronavirus 2). SARS CoV2 is one of the coronaviruses, primarily a respiratory infection with a significant impact on hematopoietic system and hemostasis. However, it is now learnt that Covid-19 also known to cause multisystem disorder with Kawasaki disease like fever in children. SARS-CoV-2 spreads via respiratory droplet and surface to human transmission via fomites where the virus can enter the mucus membrane of eyes, nose and mouth. Though asymptomatic/mild cases account for large number of cases, it is also postulated that the viral load is higher in pre-symptomatic cases compared to those with severe disease thereby making them most important overlooked viral shedders contributing to highly contagiousness of the infection. Therefore, early diagnosis of Covid-19 is critical for prevention and control of this pandemic and the clinical characteristics alone cannot define the diagnosis of Covid-19, especially for pre-symptomatic and asymptomatic patients.
Nuclei acid detection based approaches have become a rapid and reliable technology for detection of virus, and amongst them real time Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) is considered as the ‘Gold standard’ for the detection SARS-CoV-2. The real time RT-PCR has adequate sensitivity and high specificity in the diagnosis Covid-19 particularly the early infection. However, the important drawback with RT-PCR application is the risk of eliciting false-negative results which in the current pandemic can be perilous and a major impediment in the containment of outbreaks. It is reported that many ‘suspected’ cases with typical clinical characteristics of Covid-19 and diagnostic computed tomography (CT) images were not diagnosed with RT-PCR . Thus, a negative result does not exclude the possibility of Covid-19 infection entirely and therefore should not be used as the only criterion in the management of Covid-19 cases.
We carried out a study to assess the effects of SARS-CoV-2 on the hematopoietic and biochemical profile which might provide for an alternative mechanism to diagnose Covid-19, particularly in hospital settings when patients are being evaluated in the Non-Covid zone of the hospital or in resource constraint settings where Nucleic Acid based tests are not readily available for the diagnosis of Covid-19. The study was carried out on individuals who were serving in an organization that generates physically fit and mentally robust individuals, thereby weeding out affection of any other confounding factors such as obesity, cardiovascular disease and other co-morbidities on the evolution of the disease. A total of 250 Covid-19 positive patients were evaluated hematologically and biochemically between June 2020 and October 2020.
The Complete Blood Count (CBC) of the Covid-19 patients revealed normal Total Leukocyte Count (TLC) in more than 90% of patients, Leukocytopenia in less than 5% of patients, Leukocytosis in about 05% of cases and Thrombocytopenia in 5% of cases. It is pertinent to note that majority of the patients, particularly those presenting early in the course of the disease as pre-symptomatic illness, initially presented with Relative Lymphocytosis on days 2 to 3 post sampling that yielded a positive result for Covid-19. The Peripheral Blood Smear (PBS) confirmed the initial Relative Lymphocytosis with presence of characteristic Covicytes (Activated Lymphocytes) and Acquired Pseudo Pelger Huet Anomaly (APHA). With recovery, Covicytes gradually decrease in number but there is persistence of occasional covicytes which were observed in most patients who were assessed hematologically prior to discharge after being declared Covid-19 by RT-PCR testing. While the proportion of covicytes reduced as the patients recovered with improvement in symptomatology and waning viral loads, the Acquired Pseudo Pelger Huet anomaly in the neutrophils persisted for protracted periods of time and was appreciated in peripheral blood smear examination carried out when these Covid-19 recovered patients returned for blood evaluation for some other ailment weeks later.
The proposed approach also provides an alternative cheap and reliable Infection Prevention and Control mechanism in hospital settings for detecting Covid-19 cases amongst in-patients who were missed either during clinical assessment, if done cursorily or as RT-PCR false-negative cases. It will also enable efficient contact tracing, in the event of such patients being confirmed as Covid-19 positive cases. Correlation between Covicytes, APHA and inflammation associated markers such as CRP, LDH and Neutrophil to Lymphocyte Ratio (NLR) were also drawn. We analyzed that there is a linear correlation between lymphocyte decline, raised NLR, heightened inflammation markers and severity of infection.
Keywords: Pandemic; SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2); Covid-19; hematological assessment, hematological profile, Biochemical profile, Inflammatory markers, Relative lymphocytosis, Peripheral blood smear, Activated Lymphocytes, atypical lymphocytes, Covicytes, Acquired Pseudo Pelger Huet Anomaly (APHA), Quarantine, Isolation
Citation: Rakesh Holla A. “Study on the Effects of Sars-Cov-2 Infection on the Hematological and Biochemical Parameters and Clinicopathological Correlation in the Evolution of Covid-19”.Acta Scientific Medical Sciences 5.10 (2021): 47-81.
Copyright: © 2021 Rakesh Holla A. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.