Comparison of T Lymphocyte Subsets and Natural Killer Lymphocytes in Moderate Versus Severe COVID-19 Patients.

Severe respiratory involvement that follows a process of immune dysregulation and intense cytokine production remains to be the most dreaded complication of Coronavirus Disease-2019 (COVID-19) infection. The aim of this study was to analyze T lymphocyte subsets and natural killer (NK) lymphocytes in moderate and severe cases of COVID-19 infection and assess their significance in disease severity and prognosis. Twenty moderate cases and 20 severe cases of COVID-19 were studied and compared regarding blood picture, biochemical markers, T lymphocyte population subsets, and NK lymphocytes, which were determined by flow cytometric analysis. On analyzing the flow cytometric data of T lymphocyte cells and their subsets and NK cells in two groups of COVID-19 infection (one group moderate and the other severe cases), some immature NK lymphocyte relative and absolute counts were higher in the severe patients with worse outcome and death, while some mature NK lymphocyte relative and absolute counts were depressed in both groups. Also, interleukin (IL)-6 was significantly higher in severe cases when compared to moderate cases, and there was a positive significant correlation between immature NK lymphocyte relative and absolute counts and IL-6. There was no statistically significant difference between T lymphocyte subsets (T helper and T cytotoxic) with disease severity or outcome. Some immature NK lymphocyte subsets contribute to the widespread inflammatory response that complicates severe cases of COVID-19; therapeutic approaches directed to enhancing NK maturation or drugs that block NK cell inhibitory receptors have a potential role in controlling COVID-19 induced cytokine storm.

Changes in peripheral blood cellular morphology as diagnostic markers for COVID-19 infection.

INTRODUCTION: Real-time reverse-transcriptase polymerase chain reaction (RT-PCR) assays were established to detect severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). However, due to the high rate of false negative results, additional tests as computed tomography (CT) scans of the chest and blood chemistry are required to properly diagnose COVID-19 infection. Abnormal morphological changes of peripheral blood cells as granulocytic dysmorphism and abnormal reactive lymphocytes have been described in some cases. The aim of the present study was to investigate the morphological changes affecting all peripheral blood cells of COVID-19 patients, in order to find any specific abnormalities that could help in the early diagnosis and/or prognosis. METHODS: Peripheral blood smears of 113 COVID-19 patients and 50 non-COVID-19 controls were examined for morphological changes in the period between October 2020 and January 2021 (second wave). We set a score value in which every morphological abnormality was given one point in each examined blood smear. Score, neurophil/lymphocyte (N/L) ratio, and blood chemistry were compared to the severity and outcome of the disease. RESULTS: Significant morphological changes were found when compared to control blood smears. Various abnormalities as pyknotic cells, broken cells, pseudo Pelger-Huët, abnormal lymphocytes, abnormal monocytes, and leukoerythroblastic reaction were found. Cases with higher scores had unfavorable outcomes (p = .005). High interleukin-6 (IL-6) levels were correlated to pyknotic cells (p = .003). CONCLUSION: The blood picture of COVID-19 patients revealed various morphological changes that are not detected with the same frequency and variability in other viral infections. The prominent morphological changes can be predictive of an undesirable outcome of the disease.

Effect of mast cell stabilization on angiogenesis in primary and secondary experimental Trichinella spiralis infection.

BACKGROUND: Mast cells are known to affect the primary and secondary immune responses against parasites, and this effect is partially mediated through the release of pro-angiogenic mediators. The aim of this study was to explore the effect of the mast cell stabilizer (MCS), ketotifen, with and without albendazole, an anti-parasitic prescription medicine, on the inflammatory response against Trichinella spiralis, with the overall aim to investigate its effect on angiogenesis accompanying nurse cell formation. METHODS: The effect of ketotifen and albendazole was explored in eight groups of female BALB/c mice. Four groups were sensitized with a small dose of T. spiralis larvae. The drug regimen was then applied to both sensitized (challenged) and non-sensitized mice. The parasite load was assessed by histopathological examination of the small intestine and muscle tissue, and angiogenesis was assessed by immunohistochemistry to determine the expression of vascular endothelial growth factor (VEGF). RESULTS: Sensitized mice showed a significantly lower parasite load and a more pronounced inflammatory response than mice receiving a single infective dose of T. spiralis larvae. All treated groups showed a significant reduction in parasite count compared to the control groups (groups IAa and IBa), reaching approximately an 98.8% reduction in adult parasite count in the sensitized group treated with albendazole (groups IIAb and IIBb). MCS significantly decreased the parasite count during both the intestinal or muscular phases, reduced tissue inflammation, and decreased local VEGF expression, both in the non-sensitized and sensitized groups. CONCLUSION: Sensitization with a low dose of T. spiralis larvae was found to confer a partial protective immunity against re-infection and to positively affect the study outcomes, thus underlining the importance of vaccination, but after extensive studies. The anti-angiogenic effect of MCS protects against larval encystation during the muscle phase. The anti-angiogenic potential of albendazole suggests that the action of this anti-helminthic during trichinellosis is not confined to structural damage to the parasite cuticle but includes an effect on host immunopathological response.

Endothelial cell protein C receptor gene 6936A/G and 4678G/C polymorphisms as risk factors for deep venous thrombosis.

Endothelial cell protein C receptor (EPCR) enhances the generation of activated protein C by the thrombin-thrombomodulin complex. A soluble form of EPCR (sEPCR) is present in plasma. Two polymorphisms in the EPCR gene (6936A/G and 4678G/C) have been reported to influence the risk of venous thromboembolism. We aimed to investigate the relation between EPCR gene polymorphisms (6936A/G and 4678C/G) and deep venous thrombosis (DVT) and their relations to sEPCR level. This study involved 90 patients with DVT and 90 age and sex-matched healthy controls. Plasma levels of sEPCR were measured in 45 cases of the primary DVT by ELISA. PCR-restriction fragment length polymorphism (RFLP) was used for detection of EPCR polymorphisms (6936A/G and 4678G/C). Regarding 6936A/G, our results demonstrated that mutant genotypes (AG, GG) were associated with an increased risk for DVT [P < 0.001, odds ratio (OR) 4.125, 95% confidence interval (95% CI) 2.198-7.740] as well as its mutant allele G (P < 0.001, OR 2.549, 95% CI 1.601-4.061). The mutant genotypes were associated with increased levels of sEPCR. Although in 4678G/C, our results demonstrated that the mutant genotype (CC) was considered as a protective factor against DVT (P = 0.014, OR 0.289, 95% CI 0.108-0.776) as well as its mutant allele C (P = 0.02, OR 0.600, 95% CI 0.388-0.927), but it had no effect on sEPCR level. Our data suggest that 6936A/G polymorphism is a risk factor for DVT and is associated with elevated plasma levels of sEPCR, while 4678G/C polymorphism plays a role in protection against DVT.

Flow cytometric assessment of endothelial and platelet microparticles in preeclampsia and their relation to disease severity and Doppler parameters.

OBJECTIVE: Platelet (P) and endothelial (E) microparticle (MP) levels increase in preeclampsia. However, their relation to the severity of the disease needs to be clarified. The objectives of this study were to compare the levels of EMP and PMP in severe and mild preeclampsia to healthy gravidas to find possible correlations to severity of the disease, Doppler changes, and complications. METHODS: A comparative prospective clinical trial (Canadian Task Force II-1) was conducted on 135 pregnant women divided into three groups: 35 women with severe preeclampsia (group 1), 40 with mild preeclampsia (group 2), and 60 healthy gravids (group 3). Assessment of EMP and PMP was done by flow cytometry using anti-CD31 and anti-CD42b antibodies. RESULTS: Expression of CD31 and CD42b (EMPs) was higher in group 1 compared to groups 2 and 3 with P < 0.001, while expression of CD42b alone (PMPs) did not show a statistically significant difference (P = 0.957). EMPs were correlated positively to umbilical and middle cerebral artery resistance index. There was a significant negative correlation between platelet count and EMPs. Also, EMPs were correlated positively to aspartate transferase and bilirubin levels and were significantly higher with neonatal death. DISCUSSION: The present study revealed a significant association between plasma levels of EMPs and severity of preeclampsia together with poor neonatal outcome as regards birth weight and percent of neonatal death. So, EMPs assay could be a good predictor of maternal and fetal outcomes and in cases with preeclampsia.

FAS and FAS ligand gene polymorphisms in Egyptian females with preeclampsia.

We aimed to evaluate the association of Fas polymorphism and the Fas ligand with preeclampsia, investigating whether the G 670 Fas gene variant and the Fas Ligand INV2nt 124 G variant had a differential distribution in patients with preeclampsia. The preeclamptic group consisted of 50 pregnant women who developed preeclampsia, while the control group consisted of 50 age-matched pregnant women with uncomplicated pregnancies. Fas and Fas ligand gene polymorphisms were tested using polymerase chain reaction-restriction fragment length polymorphism. Regarding the Fas 670 A>G polymorphism, statistically significant differences were found between the two groups regarding the AA and GG/AG genotypes as well as the A, G allele frequency, while no statistically significant differences were found regarding AG or GG genotypes. Regarding the FasLG IVS2nt 124 A>G polymorphism, no statistically significant differences were found between the two groups studied. Concerning the Fas 670 A>G gene, no statistically significant differences between the severe and mild preeclampsia groups regarding the A allele frequency were found. Concerning the FasLG IVS2nt 124 A>G gene, there were no statistically significant differences between the severe and mild preeclampsia groups regarding the A allele frequency or the G allele frequency. The presence of the Fas gene polymorphism Fas A670G is associated with an increased risk of preeclampsia, while the presence of FasLG IVS2nt 124 A>G gene may be protective against preeclampsia.