Comparison of hematologic abnormalities between hospitalized coronavirus disease 2019 positive and negative patients with correlation to disease severity and outcome

Abstract

Peripheral blood smear (PBS) changes in coronavirus disease 2019 (COVID‐19) are diverse and have been reported in the literature in the form of case series with relatively smaller sample sizes and with a handful of studies showing the association between PBS and clinical severity. This study aims to highlight the numerical and morphological changes in peripheral blood of COVID‐19 patients and to compare the same in intensive care unit (ICU) and non‐ICU settings as well as with disease severity and outcome. The study included 80 COVID‐19 positive (41 ICU and 39 non‐ICU) patients and 32 COVID‐19 negative ICU patients. Complete blood counts (CBCs) and PBS findings were studied and scored by two pathologists blindfolded. Absolute lymphocyte count (ALC) and absolute eosinophil count (AEC) were significantly lower in COVID‐19 positive cases as compared to the COVID‐19 negative group ( p = 0.001 and p = 0.001). COVID‐19 positive group showed significant left myeloid shift ( p = 0.021), Dohle bodies ( p = 0.025) with significant prominence of acquired pseudo–Pelger–Huët anomaly, ring‐shaped neutrophils, monolobate neutrophils, and plasmacytoid lymphocytes as compared to control group ( p = 0.000, p = 0.009, p = 0.046, and p = 0.011, respectively). The overall mean white blood cell (WBC) counts were higher in COVID‐19 positive ICU patients as compared to non‐ICU COVID patients with significant shift to left, presence of ring‐shaped neutrophils, monocyte vacuolation, and large granular lymphocytes ( p = 0.017, p = 0.007, p = 0.008, and p = 0.004, respectively). Deceased group showed significantly higher WBC count ( p = 0.018) with marked neutrophilia ( p = 0.024) and toxic granulation ( p = 0.01) with prominence of monocyte vacuolization, ring‐shaped neutrophils, large granular lymphocytes, and reactive lymphocytes. Parameters like myeloid left shift, ring‐shaped neutrophils, monocyte vacuolation, and large granular lymphocytes emerged as highly sensitive markers of disease severity. Therefore, serial CBC with comprehensive PBS analysis should be done in every newly diagnosed hospitalized COVID‐19 patient which potentially predicts the course of the disease.

Fatal Gets More Fatal: A COVID-19 Infection With Macrophage Activation Syndrome

“…Initial peripheral smear on the day of admission revealed Döhle bodies that are small, round or oval, basophilic structures locating the periphery of the neutrophils. Döhle bodies are seen in bacterial infections, burns, trauma, and reportedly in COVID-19 [ 5 ].…”

Coronavirus disease 2019 (COVID‐19): Focus on peripheral blood cell morphology

“… 26 , 39 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 Not uncommonly a combination of hypergranular/toxic neutrophils with hypogranular neutrophils on the same film is reported. Presence of small basophilic, agranular cytoplasmic areas, blue areas or Döhle bodies 11 , 39 , 42 , 47 , 49 , 54 ; such pale blue areas correspond to membranes of the endoplasmic reticulum. Cytoplasmic vacuoles, 11 , 43 , 45 , 47 , 51 , 55 found in up to 95% of cases.…”

“…Presence of small basophilic, agranular cytoplasmic areas, blue areas or Döhle bodies 11 , 39 , 42 , 47 , 49 , 54 ; such pale blue areas correspond to membranes of the endoplasmic reticulum.…”

“… 43 , 55 An impressive morphological monocyte feature, highlighted by almost all authors, is an increase and dysmorphism of cytoplasmic vacuolisation, considered striking in some studies, with many large coalescing empty vacuoles. 11 , 21 , 29 , 38 , 47 , 48 , 54 Sporadic cases with haemophagocytosis images in PB have been described. 21 Blue‐green cytoplasmic inclusions, similar to those observed in neutrophils, have been seen in fatal cases.…”

“… 38 In all, 19 of these group studies detailed morphological abnormalities in multiple cell populations in patients with different phases of the disease (10 of them included control groups of healthy subjects or patients with non‐COVID‐19 inflammatory states) (Table 1 ). 11 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 Other studies described case reports or original articles specifically dedicated to red blood cell (RBC) morphological abnormalities, with particular reference to the presence of schistocytes in COVID‐19‐related microangiopathies (subsection ‘ Red blood cells ’).…”