Blood cell morphology and COVID-19 clinical course, severity, and outcome

Abstract

COVID-19 infection affects different organs of the human body, and blood cells are not an exception. Peripheral blood smear (PBS) is a simple and available method to investigate blood cells’ morphologic changes. In this study, we aimed to determine the morphologic changes and abnormalities of COVID-19 patients and their relation to the patients’ clinical course. In this prospective cross-sectional study, we included 89 PCR-positive COVID-19 patients. A pathologist examined the PBS findings of these patients. The patients’ clinical course, including severity, outcome, intubation, and ICU admission, was extracted from their profiles. The statistical analyses were done to find out the relation between PBS findings and patients’ clinical course. Results showed that smudge cells are the most frequent abnormality in our participants. Other findings were schistocyte; atypical lymphocytes; and increased large granular lymphocytes, shift to left of granulocytes, giant platelets, and leukoerythroblastic reaction. Our results did not show any statistically significant relationship between PBS findings and their clinical course. Although other studies suggested PBS as a possible predictive tool for COVID-19 disease, our study showed that these findings could not predict nor relate to the patients’ clinical course. Supplementary Information The online version contains supplementary material available at 10.1007/s12308-021-00459-3.

Hematological Profile in COVID-19 Infection Among Patients in a Tertiary Care Hospital in Tamil Nadu, South India

“…The peripheral smear findings in this study were compared to other similar studies carried out in different populations of the world. In a study conducted by Pezeshki et al [18] from Iran, the most frequent peripheral smear abnormalities were thrombocytopenia (78.7%), smudge cells (67.4%), normocytic normochromic anemia (54%), giant platelets (42.7%), atypical lymphocytes (36%), leukopenia (37.1%), leukocytosis (29.2%) and schistocytes (27%), unlike the present study (Table 10). In a study of leukocyte morphological changes in COVID-19 by Kannan et al [7] from India, the neutrophils showed acquired neutrophilic nuclear projections (ANNP), acquired Pelger-Huet anomaly (APHA), toxic granules and myeloid shift to the left while the lymphocytes showed plasmacytoid appearance (plasmacytoid lymphocytes) in comparison to the present study which showed neutrophils with ring nuclei and toxic granules.…”

“…The peripheral smear findings in this study were compared to other similar studies carried out in different populations of the world. In a study conducted by Pezeshki et al [ 18 ] from Iran, the most frequent peripheral smear abnormalities were thrombocytopenia (78.7%), smudge cells (67.4%), normocytic normochromic anemia (54%), giant platelets (42.7%), atypical lymphocytes (36%), leukopenia (37.1%), leukocytosis (29.2%) and schistocytes (27%), unlike the present study (Table 10 ).…”

“…Della Rocca et al [21] reported a schistocyte count of ≥ 1% in 70% of hospitalized COVID-19 patients and schistocytes may serve as an important biomarker to categorize the high-risk subpopulation with latent systemic microvascular damage caused by SARS-CoV-2 irrespective of respiratory symptoms. However, in another study by Pezeshki et al [18], the presence of schistocytes in peripheral smear had no prognostic significance similar to the present study where there was no statistically significant association between the presence of schistocytes in peripheral smear and the prognostic serum markers like LDH and D-dimer levels.…”

Platelets in Viral Infections – Brave Soldiers or Trojan Horses

“…Despite overall minor reduction of circulating platelets, COVID-19 is associated with increased levels of immature platelets, indicating enhanced platelet turnover ( 162 ). Blood smears of COVID-19 patients further revealed the presence of giant platelets, corroborating reports of increased MPV ( 47 , 163 , 164 ). Increased MPV is associated with disease severity ( 164 , 165 ) and acute kidney failure in COVID-19 ( 166 ), but interestingly not with ICU requirement ( 48 ).…”

Laboratory medicine in pandemic of COVID-19

“…The most common findings were the presence of large granular, lymphoplasmoid, and Downey cell-like reactive lymphocytes, pseudo Pelger-Huet anomaly, and morphologically changed monocytes ( 30 - 40 ). Other changes less frequently reported were smudged and apoptotic neutrophils and neutrophils with other dysplastic like changes like C shaped, ring-shaped, and fetus-like nuclei and nucleoplasmic elongations ( 30 , 31 , 36 , 37 ). Lymphocyte changes did not correlate with patients’ clinical course, but it has been suggested that COVID-19 could become a new aetiology for reactive lymphocytes and can maybe indicate the presence of SARS-CoV-2 before PCR confirmation ( 31 - 33 , 37 ).…”