SI12Lymphocyte Subsets Following Autologous Transfer of CD25 Depleted Leukapheresis Products

The CXCL12/CXCR4 chemokine axis is a well characterized and important chemotactic stimulus/receptor unit that orchestrates the homing and migration of cells to the bone marrow and to ischemic tissues following tissue damage. Here, we demonstrate that the sialomucin, CD164, a regulator of haemopoietic precursor cell adhesion to stroma and entry of primitive CD34⁺CD38^lo/‐ precursor cells into cycle, modulates the migration of CD133⁺ cord blood cells to CXCL12 by associating with the CXCR4 receptor. This was demonstrated by a reduction in CD133⁺ cell migration on fibronectin to CXCL12 (i) by engaging the functional class II glycosylation‐dependent epitope on CD164 with the 103B2/9E10 class II but not the N6B6 class III antibody; and (ii) by RNAi knockdown of CD164 protein levels in CD133⁺ cells. The inhibition of migration was more pronounced in the more primitive CD34⁺CD38^lo/‐ cell subset. Similar studies using the Jurkat cell line confirmed these findings and led to further analyses using alternative chemokines. A direct association between CXCR4 and CD164 was demonstrated by the co‐localisation of CD164 with CXCR4 and VLA‐4 and VLA‐5 at the leading edge of CD133⁺ cells when CXCL12 was presented on fibronectin. This was further supported by immunoprecipitation studies that demonstrate in the absence of CXCL12, CXCR4 is associated only with VLA‐4 and VLA‐5 but on exposure to CXCL12, CD164 is rapidly recruited to the CXCR4 complex. Knock‐down of CD164 using siRNA revealed that signalling through CXCR4 via PKC‐ζ was significantly dampened. Our findings therefore support a novel association between three distinct families of cell surface receptors that regulate both cell migratory and proliferative responses and identify a CD164 as a key regulator of the CXCL12/CXCR4 axis.     

Is membrane sweeping beneficial at the initiation of labor induction?

Objective: To determine whether cervical membrane sweeping during labor induction is beneficial.

Methods: Outcomes of labor after induction in pregnant women at term were compared in a randomized trial. Women were assigned to having their membranes “swept” or “not swept” at the initiation of labor induction.

Results: We recruited a total of 870 women of which 70 were excluded. There were 400 nullipara (Group A) [198 “swept”, 202 “not swept”] and 400 multiparas (Group B) (201 “swept” and 199 “not swept”]. Among group A who received intravaginal prostaglandin (PG) E₂, those who had simultaneous sweeping had significantly shorter mean induction-labor interval (12.9?±?1.3 versus 16.2?±?1.1 hours, p?=?0.046), lower mean dose of oxytocin (6.6?±?0.6 versus 10.11?±?1.4?mU/minute, p?=?0.01), and increased normal delivery rates (vaginal delivery 82.8% versus 58.6%, p?=?0.01). Sweeping also had a favorable effect on nulliparas who had ARM and received oxytocin alone (mean induction-labor interval 5.9?±?2.9 versus 10.9?±?2.6 hours p?=?0.04, mean maximum dose of oxytocin 9.8?±?1.1 versus 15.2?±?1.1?mU/min, p?=?0.01). These results were restricted to women with unfavorable cervix in Group A those who had membrane sweeping.

Conclusion: Membrane sweeping, has beneficial effects on labor and delivery, which is limited to nulliparas with unfavorable cervix requiring PGE₂ or Oxytocin alone.     

T‐cell responses and therapies against SARS‐CoV‐2 infection

Coronavirus disease 2019 (COVID‐19) is caused by SARS‐CoV‐2, a novel coronavirus strain. Some studies suggest that COVID‐19 could be an immune‐related disease, and failure of effective immune responses in initial stages of viral infection could contribute to systemic inflammation and tissue damage, leading to worse disease outcomes. T cells can act as a double‐edge sword with both pro‐ and anti‐roles in the progression of COVID‐19. Thus, better understanding of their roles in immune responses to SARS‐CoV‐2 infection is crucial. T cells primarily react to the spike protein on the coronavirus to initiate antiviral immunity; however, T‐cell responses can be suboptimal, impaired or excessive in severe COVID‐19 patients. This review focuses on the multifaceted roles of T cells in COVID‐19 pathogenesis and rationalizes their significance in eliciting appropriate antiviral immune responses in COVID‐19 patients and unexposed individuals. In addition, we summarize the potential therapeutic approaches related to T cells to treat COVID‐19 patients. These include adoptive T‐cell therapies, vaccines activating T‐cell responses, recombinant cytokines, Th1 activators and Th17 blockers, and potential utilization of immune checkpoint inhibitors alone or in combination with anti‐inflammatory drugs to improve antiviral T‐cell responses against SARS‐CoV‐2.     

Prognostic significance of an elevated creatine kinase in the absence of an elevated troponin I during an acute coronary syndrome

In patients with troponin-negative acute coronary syndromes, creatine kinase (CK)-MB elevation predicts a significantly higher risk of death and major acute cardiac events compared with CK-MB negative patients. This risk is accentuated in troponin-negative, CK-MB positive patients who do not demonstrate ST elevation by electrocardiogram.     

Exposure to war trauma and PTSD among parents and children in the Gaza strip

Objective Exposure to war trauma has been independently associated with posttraumatic stress (PTSD) and other emotional disorders in children and adults. The aim of this study was to establish the relationship between ongoing war traumatic experiences, PTSD and anxiety symptoms in children, accounting for their parents’ equivalent mental health responses. Methods The study was conducted in the Gaza Strip, in areas under ongoing shelling and other acts of military violence. The sample included 100 families, with 200 parents and 197 children aged 9–18 years. Parents and children completed measures of experience of traumatic events (Gaza Traumatic Checklist), PTSD (Children’s Revised Impact of Events Scale, PTSD Checklist for parents), and anxiety (Revised Children’s Manifest Anxiety Scale, and Taylor Manifest Anxiety Scale for parents). Results Both children and parents reported a high number of experienced traumatic events, and high rates of PTSD and anxiety scores above previously established cut-offs. Among children, trauma exposure was significantly associated with total and subscales PTSD scores, and with anxiety scores. In contrast, trauma exposure was significantly associated with PTSD intrusion symptoms in parents. Both war trauma and parents’ emotional responses were significantly associated with children’s PTSD and anxiety symptoms. Conclusions Exposure to war trauma impacts on both parents’ and children’s mental health, whose emotional responses are inter-related. Both universal and targeted interventions should preferably involve families. These could be provided by non-governmental organizations in the first instance.     

In‐vitro effect of pembrolizumab on different T regulatory cell subsets

Programmed death‐1 (PD‐1) and interactions with PD‐ligand 1 (PD‐L1) play critical roles in the tumour evasion of immune responses through different mechanisms, including inhibition of effector T cell proliferation, reducing cytotoxic activity, induction of apoptosis in tumour‐infiltrating T cells and regulatory T cell (T_reg) expansion. Effective blockade of immune checkpoints can therefore potentially eliminate these detrimental effects. The aim of this study was to investigate the effect of anti‐PD‐1 antibody, pembrolizumab, on various T_reg subpopulations. Peripheral blood mononuclear cells (PBMC) from healthy donors (HD) and primary breast cancer patients (PBC) were treated in vitro with pembrolizumab, which effectively reduced PD‐1 expression in both cohorts. We found that PD‐1 was expressed mainly on CD4⁺CD25⁺ T cells and pembrolizumab had a greater effect on PD‐1 expression in CD4⁺CD25^? T cells, compared to CD4⁺CD25⁺ cells. In addition, pembrolizumab did not affect the expression levels of T_reg‐related markers, including cytotoxic T lymphocyte antigen‐4 (CTLA‐4), CD15s, latency‐associated peptide (LAP) and Ki‐67. Moreover, we report that CD15s is expressed mainly on forkhead box P3 (FoxP3)^?Helios⁺ T_reg in HD, but it is expressed on FoxP3⁺Helios^? T_reg subset in addition to FoxP3^?Helios⁺ T_reg in PBC. Pembrolizumab did not affect the levels of FoxP3^+/?Helios^+/? T_reg subsets in both cohorts. Taken together, our study suggests that pembrolizumab does not affect T_reg or change their phenotype or function but rather blocks signalling via the PD‐1/PD‐L1 axis in activated T cells.