Imbalance of Follicular Helper and Follicular Regulatory T Cells in Chronic Rhinosinusitis with Nasal Polyps.

OBJECTIVE: Data regarding the imbalance in follicular helper T (Tfh) and follicular regulatory T (Tfr) cell responses in patients having chronic rhinosinusitis with nasal polyps (CRSwNP) is so far limited. Thus, we aimed to assess the changes in circulating Tfh and Tfr in CRSwNP patients. METHODS: This case-control study included 21 patients having CRSwNP and 20 age and sex-matched healthy blood donors as a control group. Lund-Mackay staging system was used for radiologic scoring of chronic rhinosinusitis. Two milliliters of peripheral blood samples were collected from all participants into EDTA-containing vacutainer tubes to assess the levels of Tfh and Tfr cells using flow cytometry. RESULTS: Patients having CRSwNP did not show significant differences in the percentages of CD4+ T cells and total CD4+CXCR5+ T cells from healthy controls. Meanwhile, levels of both activated circulating Tfh and Tfr showed a marked rise in patients than controls. In addition, a positive correlation was observed between the levels of both activated Tfh and Tfr cells. CONCLUSION: An imbalance in circulating Tfh/Tfr levels was detected in patients having CRSwNP. A significant rise in the levels of Tfh and Tfr was detected in patients proposing a possible role of this imbalance in disease pathogenesis.

Elevated CD39+T-Regulatory Cells and Reduced Levels of Adenosine Indicate a Role for Tolerogenic Signals in the Progression from Moderate to Severe COVID-19.

Viral infections trigger inflammation by controlling ATP release. CD39 ectoenzymes hydrolyze ATP/ADP to AMP, which is converted by CD73 into anti-inflammatory adenosine (ADO). ADO is an anti-inflammatory and immunosuppressant molecule which can enhance viral persistence and severity. The CD39-CD73-adenosine axis contributes to the immunosuppressive T-reg microenvironment and may affect COVID-19 disease progression. Here, we investigated the link between CD39 expression, mostly on T-regs, and levels of CD73, adenosine, and adenosine receptors with COVID-19 severity and progression. Our study included 73 hospitalized COVID-19 patients, of which 33 were moderately affected and 40 suffered from severe infection. A flow cytometric analysis was used to analyze the frequency of T-regulatory cells (T-regs), CD39+ T-regs, and CD39+CD4+ T-cells. Plasma concentrations of adenosine, IL-10, and TGF-ß were quantified via an ELISA. An RT-qPCR was used to analyze the gene expression of CD73 and adenosine receptors (A1, A2A, A2B, and A3). T-reg cells were higher in COVID-19 patients compared to healthy controls (7.4 ± 0.79 vs. 2.4 ± 0.28; p < 0.0001). Patients also had a higher frequency of the CD39+ T-reg subset. In addition, patients who suffered from a severe form of the disease had higher CD39+ T-regs compared with moderately infected patients. CD39+CD4+ T cells were increased in patients compared to the control group. An analysis of serum adenosine levels showed a marked decrease in their levels in patients, particularly those suffering from severe illness. However, this was paralleled with a marked decline in the expression levels of CD73. IL-10 and TGF-ß levels were higher in COVID-19; in addition, their values were also higher in the severe group. In conclusion, there are distinct immunological alterations in CD39+ lymphocyte subsets and a dysregulation in the adenosine signaling pathway in COVID-19 patients which may contribute to immune dysfunction and disease progression. Understanding these immunological alterations in the different immune cell subsets and adenosine signaling provides valuable insights into the pathogenesis of the disease and may contribute to the development of novel therapeutic approaches targeting specific immune mechanisms.

Memory T Cells Discrepancies in COVID-19 Patients.

The immune response implicated in Coronavirus disease 2019 (COVID-19) pathogenesis remains to be fully understood. The present study aimed to clarify the alterations in CD4+ and CD8+ memory T cells' compartments in SARS-CoV-2-infected patients, with an emphasis on various comorbidities affecting COVID-19 patients. Peripheral blood samples were collected from 35 COVID-19 patients, 16 recovered individuals, and 25 healthy controls, and analyzed using flow cytometry. Significant alterations were detected in the percentage of CD8+ T cells and effector memory-expressing CD45RA CD8+ T cells (TEMRA) in COVID-19 patients compared to healthy controls. Interestingly, altered percentages of CD4+ T cells, CD8+ T cells, T effector (TEff), T naïve cells (TNs), T central memory (TCM), T effector memory (TEM), T stem cell memory (TSCM), and TEMRA T cells were significantly associated with the disease severity. Male patients had more CD8+ TSCMs and CD4+ TNs cells, while female patients had a significantly higher percentage of effector CD8+CD45RA+ T cells. Moreover, altered percentages of CD8+ TNs and memory CD8+CD45RO+ T cells were detected in diabetic and non-diabetic COVID-19 patients, respectively. In summary, this study identified alterations in memory T cells among COVID-19 patients, revealing a sex bias in the percentage of memory T cells. Moreover, COVID-19 severity and comorbidities have been linked to specific subsets of T memory cells which could be used as therapeutic, diagnostic, and protective targets for severe COVID-19.

Phenotypical changes of hematopoietic stem and progenitor cells in COVID-19 patients: Correlation with disease status.

Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) play a crucial role in the context of viral infections and their associated diseases. The link between HSCs and HPCs and disease status in COVID-19 patients is largely unknown. This study aimed to monitor the kinetics and contributions of HSCs and HPCs in severe and non-severe COVID-19 patients and to evaluate their diagnostic performance in differentiating between healthy and COVID-19 patients as well as severe and non-severe cases. Peripheral blood (PB) samples were collected from 48 COVID-19 patients, 16 recovered, and 27 healthy controls and subjected to deep flow cytometric analysis to determine HSCs and progenitor cells. Their diagnostic value and correlation with C-reactive protein (CRP), D-dimer, and ferritin levels were determined. The percentages of HSCs and common myeloid progenitors (CMPs) declined significantly, while the percentage of multipotent progenitors (MPPs) increased significantly in COVID-19 patients. There were no significant differences in the percentages of megakaryocyte-erythroid progenitors (MEPs) and granulocyte-macrophage progenitors (GMPs) between all groups. Severe COVID-19 patients had a significantly low percentage of HSCs, CMPs, and GMPs compared to non-severe cases. Contrarily, the levels of CRP, D-dimer, and ferritin increased significantly in severe COVID-19 patients. MPPs and CMPs showed excellent diagnostic performance in distinguishing COVID-19 patients from healthy controls and severe from non-severe COVID-19 patients, respectively. Collectively, our study indicated that hematopoietic stem and progenitor cells are significantly altered by COVID-19 and could be used as therapeutic targets and diagnostic biomarkers for severe COVID-19.

Could the Crosstalk Between Myeloid-Derived-Suppressor Cells and Regulatory T Cells Have a Role in Beta-Thalassemia?

Background: Secondary iron overload, alloimmunization, and increased risk of infection are common complications in patients with transfusion-dependent thalassemia (TDT). Regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) play an essential role in preventing excessive immune response. This research aimed to study the interaction between Tregs and MDSCs in TDT patients and to evaluate the association of these cell types with disease severity. Methods: This case-control study included 26 patients with TDT and 23 healthy, age- and sex-matched controls. All patients were investigated for complete blood count (CBC), serum ferritin, and flow cytometric analysis of peripheral blood to detect Tregs, MDSCs, and MDSC subsets. Results: A significant increase was observed in the frequencies of Tregs and MDSCs, particularly monocytic MDSCs (MO-MDSCs), in TDT patients compared with controls. The frequencies of these cells showed a direct association with ferritin level and total leukocyte count and an inverse association with hemoglobin level. Furthermore, a positive correlation was observed between Tregs and each of the total MDSCs and MO-MDSCs. Conclusions: Levels of Tregs and MDSCs increased in TDT and may probably have a role in suppressing the active immune systems of TDT patients.

Frequency of rifampicin-resistant mycobacterium tuberculosis by GeneXpert MTB/RIF assay and its correlates among 2605 probable tuberculosis patients in upper Egypt.

RATIONALE: GeneXpert MTB/RIF (Mycobacterium tuberculosis/rifampicin) assay is a method for detecting rifampicin resistance (RR-MTB) in suspected samples in less than 2 hours with high sensitivity and specificity yield. This study aimed to use the GeneXpert MTB/RIF assay to determine the frequency of RR-MTB and to study the possible influencing correlates associated with positive results. SUBJECTS AND METHODS: This is a retrospective cross-sectional study of patients who visited TB clinic in 5 years (2016-2021). According to the data sheet of the patients, all the collected specimens were divided into 2 parts one for diagnosis by Ziehl-Neelsen stain and the other part for GeneXpert analysis. GeneXpert was also used to look for evidence of RR. RESULTS: Out of the 2605 total samples screened, 718 (27.6%) tested positive for MTB on GeneXpert assay; of them 633 (88.4%) were sensitive to Rifampicin, 83 (11.6%) were resistant to Rifampicin and 2 cases were undetermined. Factors contributing to RR-MTB were: smoker/ex-smoker, with 2.5 times more risk (p = 0.013.0, p = 0.001); recurrence cases had a 4-fold increased risk (p < 0.001); patients with very low M. tuberculosis detected on the GeneXpert MTB/RIF test were 8 times more likely to have RR-TB (P = 0.004). CONCLUSION: This study disclosed a high-rate MTB in Egyptian probable TB cases. Smoking, recurrence and cases with a very low M. tuberculosis burden noticed on the GeneXpert MTB/RIF test had augmented risk of RR-TB.

T cell subsets, regulatory T, regulatory B cells and proinflammatory cytokine profile in Schistosoma haematobium associated bladder cancer: First report from Upper Egypt.

BACKGROUND: The function of different populations of the immune system in bladder cancer (BCa) is well established. However, the cohesive role of the immune cell profile of schistosomal BCa at systemic and tissue levels is still lacking, especially in endemic countries. The balance hypothesized between protumorigenic and antitumor molecules determines the prognosis of tumor progression. This study aimed to investigate the frequency of T cell subsets at both blood and tumor tissue, regulatory T(Treg), regulatory B cells (Breg) and proinflammatory cytokines in S. haematobium-related BCa patients in Egypt. METHODOLOGY/PRINCIPAL FINDINGS: The frequency of T cell subsets at both blood and tumor tissue, regulatory T(Treg), regulatory B cells (Breg) were studied by flow cytometry and proinflammatory cytokines by ELISA in S. haematobium-related BCa patients in Egypt. The results indicated a significant increase in the activity of T-cell populations, particularly CD3+, CD4+, and regulatory T cells (Tregs), and a decrease in cytotoxic CD8+ T cells in the patient group. An increased proportion of CD19+CD24+CD38+ Bregs and proinflammatory cytokines (IL-1ß, IL-6, and TNF-α) was also observed. However, T-cell subpopulations in the tumor microenvironment showed a significant reduction in cancer patients compared to controls. Moreover, positive correlations were observed between the frequencies of Bregs and Tregs, suggesting the promotion of cancer progression besides their relation to the intensity of schistosomal infection. CONCLUSIONS/SIGNIFICANCE: Trapped Schistosoma haematobium eggs in bladder tissue might lead to persistent inflammation that contributes to immunomodulation and promotes tumor progression, as evidenced by the increase in peripheral T helper, Tregs, Bregs and serum tumor-promoting cytokines. Considering the role and integrated functions of specific immune responses in BCa could help future diagnostic and therapeutic implications.

Markers of inflammasome activation in Coronavirus disease 2019 (COVID-19) Egyptian patients: Impact on disease severity.

There are conflicting data regarding the relationship between coronavirus disease 2019 (COVID-19) severity and Caspase-1 (Casp-1), interleukin-1ß (IL-1ß), and IL-18. Our study sought to quantify the levels of IL-18, IL-1ß, and Casp-1 as indicators for inflammasome activation in COVID-19 patients at Assiut University Hospitals and to correlate their levels with parameters of disease severity in COVID-19 patients. Serum levels of Casp-1, IL-1ß and IL-18 were measured in 63 COVID-19 patients and 26 normal controls by an enzyme linked immunosorbent assay (ELISA). Also, arterial blood gas analysis and laboratory parameters including hemoglobin, platelets, lymphocyte count, liver function test, kidney function test, C-reactive protein (CRP), D-dimer, ferritin and LDH were estimated. Serum levels of Casp-1, IL-1ß and IL-18 were significantly higher in the COVID-19 group as compared to controls (p= 0.04, p=0.001 and p=0.03, respectively). Although the three markers were higher in the severe group, yet only IL-1ß showed a significant difference as compared to the non-severe group (p=0.04). IL-18 had significant positive correlations with CRP and ferritin (p = 0.04 and p = 0.02, respectively). IL-1ß was positively correlated with alanine aminotransferase. Casp-1 had significant positive correlations with CRP and lactate dehydrogenase (p=0.045 and p=0.001, respectively). Patients showed weak positive correlations between serum level of Casp-1 and each of IL-1ß and IL-18. Also, a strong positive correlation was found between IL-1ß and IL-18 (p < 0.0001). In conclusion, inflammasome activation was a hallmark in COVID-19 patients. The markers of activation were positively correlated with many parameters of inflammation, may suggest their important roles in the pathophysiology of the disease and its progression. IL-1ß was the only marker to be correlated with disease severity and therefore may be suggested as a potential marker for identifying severe COVID-19 patients.

Cross-Talk between Mucosal-Associated Invariant T, Natural Killer, and Natural Killer T Cell Populations is Implicated in the Pathogenesis of Placenta Accreta Spectrum.

The study included 32 women with PAS and 20 with normally implanted placenta as a control group. Vascular endothelial cell growth factor (VEGF), Soluble FMS Like Tyrosine Kinase (sFLT-1/sVEGFR1), and Endoglin (ENG) were measured in placenta tissue by ELISA. Granzyme B (GrzB) expression in trophoblastic and stromal mesenchymal cells was evaluated by immunohistochemistry. MAIT, NK, and NKT cells were assessed in blood and placenta by flow cytometry. Alterations were observed in levels of MAIT cells, NK cell subsets, and NKT cells in patients compared with controls. Several significant correlations were detected between these cells and GrzB scores, VEGF, ENG, and sFLT-1 levels. This is the first study analysing these cells in PAS patients and correlating their levels with changes in some angiogenic and antiangiogenic factors implicated in trophoblast invasion and with GrzB distribution in trophoblast and stroma. Interrelation between these cells probably plays an important role in pathogenesis of PAS.

Impact of hydroxyurea on lymphocyte subsets in children with sickle cell anemia.

BACKGROUND: Hydroxyurea (HU) has beneficial effects in the management of sickle cell anemia (SCA), but there is a paucity of data on the effect of HU on immune cells in SCA. Herein we aimed to evaluate the effect of HU on immune profiles of Egyptian children with SCA. METHODS: This was a controlled prospective cohort study conducted in 30 children with SCA and 30 healthy age-matched controls. Flow cytometry was used to evaluate lymphocyte profiles, including CD8+ T, CD19+ B, CD3+, CD4+, natural killer (NK), NK T, T helper 1 (Th1), Th2, T cytotoxic (Tc1), and Tc2 cells, prior to and after 1 year of treatment with HU. RESULTS: HU treatment led to significant increases in hemoglobin (Hb), red blood cell, and hematocrit counts and a significant decrease in the percentage of sickle Hb, with subsequent improvement in SCA complications. Compared with baseline values, CD3+, CD4+, Th1, and CD8+ T cells were significantly increased, while NK, Th2, and Tc2 cells were significantly decreased, with a resulting increase in the Th1/Th2 and Tc1/Tc2 ratios. CONCLUSIONS: HU has the beneficial effect of restoring the abnormally elevated immune parameters in children with SCA. IMPACT: Hydroxyurea treatment restores the abnormal immune parameters in children with sickle cell anemia. HU treatment led to significantly increased CD3+, CD4+, Th1, and CD8+ T cells, while NK, Th2, and Tc2 cells were significantly decreased, with a resulting increase in the Th1/Th2 and Tc1/Tc2 ratios. Our study showed the impact of HU therapy on immune parameters in children with SCA.

The dogma of cetuximab in advanced squamous cell carcinoma of the head and neck after failure of surgery and radiotherapy: is it true among patients in upper Egypt?

Background and aim: We aimed from the current study to explore the treatment results of cetuximab in combination with a weekly carboplatin and paclitaxel regimen in advanced squamous cell carcinoma of head and neck (HNSCC) after failure of radiotherapy and chemotherapy. Methods: This study was a non-randomised, single arm, phase 2 efficacy study conducted in two oncology centres in upper Egypt, we recruited 31 patients with recurrent HNSCC previously treated with concurrent chemoradiation ± surgery to receive weekly cetuximab, carboplatin and paclitaxel for 18 weeks followed by maintenance cetuximab every 2 weeks for 12 months. All patients underwent intention to treat analysis. Results: The current study revealed a significant reduction of the size of recurrent primary lesion (p < 0.001), without comparable significant reduction of regional lymph nodes (LNs) (p = 0.06), the current overall response rate (ORR) was 83.9%, ≥1-year progression-free survival (PFS) was 58.1%, also surgical intervention was succeeded to salvage 32.3% who did not achieve complete response to the current protocol, the median PFS was 12 months which was significantly affected by tumour site (p = 0.012), programmed death ligand-1 (PDL-1) expression (p = 0.01) and overall response rate (ORR) (p < 0.001). Conclusion: Based on favourable treatment outcomes, including high ORR and disease control rate, improved median PFS and tolerable toxicity profile, the current weekly cetuximab, carboplatin and paclitaxel with 1 year maintenance cetuximab in responding patients is considered a feasible and effective regimen.

Delineation of T cell subsets in chronic rhinosinusitis with nasal polyps.

Objectives: Detailed characterisation of CD45RA+ and CD45RO+ T cell subsets in both CD4+ and CD8+ cells in blood and tissue of patients with chronic rhinosinusitis with nasal polyps (CRSwNP) is lacking. We aimed to investigate T cell differentiation levels in blood and tissue and correlate this with CT score and white blood cell count. Methods: This case-control study was conducted on 21 patients with CRSwNP and 20 healthy controls. Lund-Mackay score was used for radiologic staging of chronic rhinosinusitis. T cell subsets were characterised in blood and nasal polyp tissue using CD4, CD8, CCR7, CD45RA, CD45RO, CD27, and CD95 monoclonal antibodies. Results: Most variations in T cell subsets were detected in tissue rather than blood. A higher level of CD8+ TCM, CD4+ TSCMs and lower level of CD8+ TEM were detected in the blood of CRSwNP patients vs controls. In CRSwNP patients, substantial decrease of tissue CD8+ TNs, CD8+ TCMs, CD4+ TNs, and CD4+TSCMs with marked increase in the percentages of TEMs and TEMRAs were detected among CD4+ and CD8+ T cells compared with levels in blood. Conclusions: The reduction of TNs, TSCMs, and TCMs and accumulation of TEMs and TEMRAs subsets that function as effector cells in sinonasal mucosa, especially CD8+ T cells, might indicate the role of immunomodulation of memory/effector T-cells in the pathogenesis of CRSwNP.

Increased percentage of apoptotic and CTLA-4 (CD152) expressing cells in CD4+/CD8+ cells in COVID-19 patients.

Coronavirus infectious disease 2019 (COVID-19) confirmed cases are characterized by T lymphopenia. Total apoptotic and cytotoxic T-lymphocyte antigen-4 (CTLA-4) expressing cells among CD4+/CD8+ cells were analyzed in 24 COVID-19 patients (16 out-patients and 8 in-patients) and 18 healthy volunteers using flow cytometry to detect their possible role in T lymphopenia. Hospitalized patients did not show significant difference compared to non-hospitalized patients. While the percentage and absolute count of CD4+/CD8+ cells were significantly reduced in COVID-19 cases compared to healthy control (P < .05), the proportion of apoptotic and CTLA-4 expressing CD4+/CD8+ cells were significantly up-regulated in COVID-19 patients (P < .05). In addition, apoptotic and CTLA-4+/CD4+ cells were directly related to dyspnea duration, chest CT score, ferritin, and C-reactive protein and inversely correlated with platelet count in COVID-19 patients. While apoptotic and CTLA-4+/CD8+ cells were directly related to lymphocyte count in COVID-19 patients. The apoptotic and CTLA-4+ cells were directly related to each other in CD4+/CD8+ cells (P < .05). White blood cells (WBCs) (×103/L), eosinophils (ratio and count), lymphocyte ratio, neutrophil ratio, neutrophil/lymphocyte ratio, neutrophil/CD4 ratio, neutrophil/CD8 ratio, CD4+ cells ratio, and CTLA-4+ cells percentage), and CD8+ cells (ratio, count, total apoptotic cell, and CD152 + cells) were all found to be significantly altered in association with COVID-19. Total lymphopenia and depletion of CD4+/CD8+ cells are characterizing COVID-19 patients. Increased apoptosis and CTLA-4 expression in CD4+/CD8+ cells in COVID-19 and their correlations with reduced cell count and severity indicators as CRP and ferritin can be used for diagnosis and follow up of the clinical severity. Our current study proposes promising future diagnostic and therapeutic targets.

Genistein anticancer efficacy during induced oral squamous cell carcinoma: an experimental study.

BACKGROUND: About 7 million people die from various types of cancer every year representing nearly 12.5% of deaths worldwide. This fact raises the demand to develop new, effective anticancer, onco-suppressive, and chemoprotective agents for the future fighting of cancers. Genistein exhibits pleiotropic functions in cancer, metabolism, and inflammation. It functions as an antineoplastic agent through its effect on the cell cycle, apoptotic processes, angiogenesis, invasion, and metastasis. AIM OF THE STUDY: The current study aimed to study the genistein onco-suppressive effects during 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters' buccal pouch utilizing flow cytometry analysis (FMA), as a fast-diagnosing tool, in addition to the histopathology. MATERIAL AND METHODS: The buccal mucosa of adult male Syrian hamsters was painted with paraffin oil only (group 1), DMBA mixed in mineral oil (group 2), or orally administrated genistein along with painting DMBA (group 2B). The buccal mucosa was utilized for flow cytometric analysis and histopathological examination. RESULTS: Grossly, DMBA-induced carcinogenesis started at the 9th week. Progressive signs appeared in the following weeks reaching to large ulcerative oral masses and exophytic nodules at the 21st week. Histologically, invasive well-differentiated oral squamous cell carcinoma (OSCC) appeared in the underlying tissues from the 12th week, showing malignant criteria. Genistein had delayed clinicopathological change, which started 6 weeks later, than the DMBA-painted hamsters, as mild epithelial dysplastic changes. This became moderate during the last 6 weeks, without dysplastic changes. Flow cytometry revealed that DMBA led to considerable variation in DNA proliferation activity, aneuploid DNA pattern, in 47.22% of hamsters and significantly raised the S-phase fragment (SPF) values, which drastically reduced after genistein treatment. CONCLUSION: Taken together, genistein could be employed as an onco-suppressive agent for carcinogenesis. Moreover, FMA could be used as an aiding fast tool for diagnosis of cancer.

COVID-19 Infection in Patients with Comorbidities: Clinical and Immunological Insight.

AIM: Our study's objectives were to study the clinical and laboratory characteristics that may serve as biomarkers for predicting disease severity, IL-10 levels, and frequencies of different T cell subsets in comorbid COVID-19 patients. METHODS: Sixty-two hospitalized COVID-19 patients with comorbidities were assessed clinically and radiologically. Blood samples were collected to assess the T lymphocyte subsets by flow cytometry and IL-10 levels by ELISA. RESULTS: The most common comorbidities observed in COVID-19 patients were diabetes mellitus (DM), hypertension, and malignancies. Common symptoms and signs included fever, cough, dyspnea, fatigue, myalgia, and sore throat. CRP, ferritin, D dimer, LDH, urea, creatinine, and direct bilirubin were significantly increased in patients than controls. Lymphocyte count and CD4+ and CD8+ T-cells were significantly decreased in comorbid COVID-19 patients, and CD25 and CD45RA expression were increased. CD4+ and CD8+ regulatory T cells (Tregs) and IL-10 levels were significantly decreased in patients. CONCLUSIONS: Many parameters were found to be predictive of severity in the comorbid patients in our study. Significant reductions in the levels and activation of CD4+ and CD8+ T-cells were found. In addition, CD4+ and CD8+ Tregs were significant decreased in patients, probably pointing to a prominent role of CD8+ Tregs in dampening CD4+ T-cell activation.

Corrigendum: Higher proportion of non-classical and intermediate monocytes in newly diagnosed multiple myeloma patients in Egypt: A possible prognostic marker.

[This corrects the article DOI: 10.4102/ajlm.v10i1.1296.].

Association of follicular helper T and follicular regulatory T cells with severity and hyperglycemia in hospitalized COVID-19 patients.

We aimed to determine the levels of follicular helper T (Tfh) and follicular regulatory T (Tfr) cells in COVID-19 patients and determine whether their levels correlated with disease severity and presence of hyperglycemia. This study was carried out in 34 hospitalized COVID-19 patients and 20 healthy controls. Levels of total circulating Tfh, inducible T-cell costimulator (ICOS)+ activated Tfh, and Tfr cells were assessed in all participants by flow cytometry. Total CD4+CXCR5+ Tfh cells and ICOS+Foxp3-activated Tfh cells increased and ICOS+Foxp3+ Tfr cells decreased in COVID-19 patients, especially in diabetic patients and those with severe disease. Activated ICOS+ Tfh cells were directly correlated with lactate dehydrogenase, D-dimer, ferritin, and respiratory rate and inversely correlated with the partial pressure of carbon dioxide. COVID-19 is associated with marked activation of Tfh cells and a profound drop in Tfr cells, especially in severe and diabetic patients. Future studies on expanded cohorts of patients are needed to clarify the relationship between SARS-CoV-2 and acute-onset diabetes.

Upregulation of Cytotoxic T-cells in pediatric patients with Gaucher disease.

Cytotoxic (CD8) T-cells and natural killer (NK) cells have a significant immune function role. The ongoing stimulation of immunity and the excessive release of proinflammatory cytokines observed in pediatric patients with Gaucher disease (GD) can affect immune cells. Few studies have looked at the proportion of cytotoxic CD8 T-cells and their subsets in children with GD. A prospective case-control study was performed involving twenty pediatric patients with type 1 GD and twenty healthy age-matched controls. All patients received regular enzyme replacement therapy (ERT) for at least 6 months before the study. Complete blood count and flow cytometric analyses of CD8 T, Tc1, Tc2, NK, and NK T-cells were performed. GD patients showed significantly increased of CD8 T, Tc1 and significantly decreased NK cells frequencies when compared to healthy controls. However, no significant difference in Tc2 and NK T-cells was found between the studied groups. GD patients on regular ERT have increased CD8+ T-cell frequencies, predominantly Tc1, together with a reduction in NK cells than in healthy controls. These crucial immunological changes may contribute to some extent to the pathogenesis and the progression of GD.

Overexpression of PD-1 and CD39 in tumor-infiltrating lymphocytes compared with peripheral blood lymphocytes in triple-negative breast cancer.

BACKGROUND AND AIM: Growing evidence highlighted the primary role of the immune system in the disease course of triple-negative breast cancer (TNBC). The study aim was to investigate the expression of PD-1 and CD39 on CD4+ and CD8+ cells infiltrating tumor tissue compared to their counterparts in peripheral blood and explore its association with tumor characteristics, disease progression, and prognosis in females with TNBC. PATIENTS AND METHODS: The study included 30 TNBC patients and 20 healthy controls. Cancer and normal breast tissue and peripheral blood samples were collected for evaluation of the expression of PD-1 and CD39 on CD4+ and CD8+T cells by flow cytometry. RESULTS: A marked reduction in the percentage of CD8+ T lymphocytes and a significant increase in the frequencies of CD4+ T lymphocytes and CD4+ and CD8+ T lymphocytes expressing PD1 and CD39 were evident in tumor tissue in comparison with the normal breast tissue. The DFS was inversely related to the cancer tissue PD1+CD8+ and CD39+CD8+ T lymphocytes. Almost all studied cells were significantly increased in the tumor tissue than in peripheral blood. Positive correlations were detected among peripheral PD1+CD4+T lymphocytes and each of cancer tissue PD1+CD4+, PD1+CD8+and CD39+CD8+T cells, and among peripheral and cancer tissue CD39+CD4+and CD39+CD8+ T cells. CONCLUSIONS: The CD39 and PD1 inhibitory pathways are synergistically utilized by TNBC cells to evade host immune response causing poor survival. Hence, combinational immunotherapy blocking these pathways might be a promising treatment strategy in this type of cancer.

Regulatory T-cell phenotypes in children with sickle cell disease.

BACKGROUND: Regulatory T cells (Tregs) are linked to a reduction in alloreactive immune responses, but few studies have investigated the impact of hydroxyurea (HU) therapy on Tregs in sickle cell disease (SCD). METHODS: Our case-controlled study presented here included two groups, the first comprising 60 pediatric SCD patients, 30 of whom did not receive any treatment and 30 who received HU, and the second group consisting of 30 healthy controls. Flow cytometry was used to evaluate the percentage of CD4+CD25+highFoxp3+ Tregs present and their phenotypes. RESULTS: The percentage of CD4+CD25+high Tregs was significantly increased in untreated SCD patients in comparison to treated SCD patients and controls. Conversely, treated SCD children had a lower percentage of CD4+CD25+high Tregs than controls. In addition, a significant increase in the percentage of CD4+CD25+highFoxp3+ Tregs was found in untreated SCD patients, compared to in HU-treated patients and controls. The percentage of naive CD45RA+ Tregs was significantly decreased in untreated SCD patients when compared to other groups. CONCLUSIONS: Among children with SCD, HU treatment exhibited significant qualitative and quantitative effects on Tregs by decreasing their frequency, and increasing the proportion of naive CD45RA+ Tregs and reducing levels of the most suppressive Tregs: HLA-DR+, CD39+, and CD69+. IMPACT: Among children with, SCD, HU treatment exhibited significant qualitative and quantitative effects on Tregs. HU treatment in SCD decreases the frequency of Tregs, as well as the levels of the most suppressive Tregs: HLA-DR+, CD39+, and CD69+. At the same time, HU increases the proportion of naive CD45RA+ Tregs. Our study showed the impact of HU therapy on Tregs in children with SCD.