Piezo1 facilitates optimal T cell activation during tumor challenge

Functional effector T cells in the tumor microenvironment (TME) are critical for successful anti-tumor responses. T cell anti-tumor function is dependent on their ability to differentiate from a naïve state, infiltrate into the tumor site, and exert cytotoxic functions. The factors dictating whether a particular T cell can successfully undergo these processes during tumor challenge are not yet completely understood. Piezo1 is a mechanosensitive cation channel with high expression on both CD4+ and CD8+ T cells. Previous studies have demonstrated that Piezo1 optimizes T cell activation and restrains the CD4+ regulatory T cell (Treg) pool in vitro and under inflammatory conditions in vivo. However, little is known about the role Piezo1 plays on CD4+ and CD8+ T cells in cancer. We hypothesized that disruption of Piezo1 on T cells impairs anti-tumor immunity in vivo by hindering inflammatory T cell responses. We challenged mice with T cell Piezo1 deletion (P1KO) with tumor models dependent on T cells for immune rejection. P1KO mice had the more aggressive tumors, higher tumor growth rates and were unresponsive to immune-mediated therapeutic interventions. We observed a decreased CD4:CD8 ratio in both the secondary lymphoid organs and TME of P1KO mice that correlated inversely with tumor size. Poor CD4+ helper T cell responses underpinned the immunodeficient phenotype of P1KO mice. Wild type CD8+ T cells are sub-optimally activated in vivo with P1KO CD4+ T cells, taking on a CD25loPD-1hi phenotype. Together, our results suggest that Piezo1 optimizes T cell activation in the context of a tumor response.

"SCULP" study: The benefits of skin graft pellets on the pain of sickle cell leg ulcers (SCLU)

BACKGROUND

Leg ulcers associated with major sickle cell disease (SCLU) are a chronic, painful complication, often treated by autologous skin graft. The analgesic effect of skin grafting in SCLU is poorly studied. The aim of this study was to evaluate the effect of skin grafting on the pain and healing of SCLU.

METHODS

Patients hospitalized for SCLU skin grafting were included in a retrospective and prospective observational cohort, between 2019 and 2023: 53 autologous pinch grafts were performed on a total of 35 SCLUs in 25 sickle cell patients. The primary endpoint was the evaluation of the analgesic effect of the skin graft, measured by visual analog scale (VAS) and weekly cumulative analgesic consumption between day (D)0, D7 and D30. Wound healing was assessed by variation in wound areas between D0 and D30.

RESULTS

Twenty-five patients with a median age range of 45.5years old were included, 68% were men, SS genotype was present in 96% of the cases. At D7, a significant decrease in VAS and consumption of analgesics of all classes was observed. At D30, only a significant decrease in VAS and consumption of mild opioids was present, as well as a significant reduction in wound surface area compared with D0.

CONCLUSION

Pinch grafts have a significant early analgesic effect in the management of patients with SCLU, and significantly notice reduction of wound surface area within one month.

Preventive treatment of unruptured intracranial aneurysms in adult patients with sickle cell anemia: A cohort study

BACKGROUND AND PURPOSE

Intracranial aneurysms are frequent in patients with sickle cell anemia, while subarachnoid hemorrhage is a major cause of death and disability in young adult patients. Several characteristics, such as younger age and smaller size at rupture, may incline therapeutic decision towards exclusion treatments. Clinical guidelines on treatment of unruptured intracranial aneurysms in this population are still missing. We aimed to assess the safety and efficacy of the treatment of unruptured intracranial aneurysm in patients with sickle cell anemia, using an adapted hematological preparation regimen.

PATIENTS AND METHODS

Adult patients with sickle cell anemia and treated unruptured aneurysms by endovascular therapy or neurosurgery were included in this retrospective cohort study. Treatment decision was reached after multi-disciplinary assessment. A pre-operative blood transfusion protocol was undertaken targeting a HbS below 30%. Demographic data, hematological preparation parameters and clinical and radiological outcomes were documented.

RESULTS AND CONCLUSIONS

Twenty-five procedures were performed in 18 patients encompassing 19 aneurysms treated by embolization and 6 by surgery. Median age at treatment was 34 years-old and median aneurysm dome size was 4.4 mm. Immediate aneurysm exclusion rate was 85.7% after endovascular therapy and 100% after neurosurgery. Median follow-up was 6 months, with all patients being asymptomatic at last follow-up. Two transitory ischemic neurological deficits, as well as four cases of iodine-induced encephalopathy were identified after embolization. No complication occurred after surgery. Endovascular therapy by coiling and neurosurgical treatment of unruptured intracranial aneurysms appears to be safe in patients with sickle cell anemia and should be considered given the specific hemorrhagic risk observed in this population. A rigorous hematological preparation, associated with a dedicated peri‑operative protocol and an adequate therapeutic strategy are essential prerequisites.

Potential therapeutic activity of adecatumumab (MT201), a fully human monoclonal antibody, against epithelial cell adhesion molecule (EpCAM) in uterine serous papillary carcinoma

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Background: Uterine serous papillary carcinoma (USPC) represents a variant of endometrial cancer characterized by a highly aggressive biologic behavior and inborn resistance to chemotherapy. MT201 is a fully human monoclonal antibody recently developed against epithelial cell adhesion molecule (EpCAM). In this study we have evaluated the potential of MT201 as a novel therapeutic strategy against USPC. Methods: EpCAM expression was evaluated by real time-PCR and immunohistochemistry (IHC) in a total of 54 USPC fresh-frozen biopsies and paraffin embedded tissues. EpCAM surface expression was evaluated by flow cytometry in 6 freshly established USPC cell lines derived from advanced stage USPC patients. Sensitivity to MT201 antibody dependent cellular cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC) was tested in standard 4-hour chromium (51Cr) release cytotoxicity assays. Results: EpCAM transcript was significantly overexpressed in fresh frozen USPC when compared to fresh-frozen normal endometrial cells (NEC) [i.e., mean (minimum-maximum) copy number of 515.4 (31.5–1568.3) in tumor samples versus 8.1 (1.0–25.5) in flash-frozen NEC (p < 0.001)]. By IHC, EpCAM protein expression was found in 96% (26 out of 27) USPC samples and this expression was significantly higher when compared to normal endometrial cells (p < 0.01). High surface expression of EpCAM by flow cytometry was found in 83% (5 out of 6) of the primary USPC cell lines available to this study. Importantly, while primary USPC cell lines were highly resistant to natural killer dependent cytotoxicity in vitro, EpCAM positive cell lines were found highly sensitive to MT201-mediated ADCC. Human serum IgG did inhibit MT201-mediated cytotoxicity against USPC in vitro. Conclusions: These results demonstrate for the first time high EpCAM expression in uterine serous carcinoma at mRNA and protein levels and high sensitivity to MT201-mediated cytotoxicity in vitro by primary USPC cell lines. MT201 might be a novel and attractive therapeutic strategy in patients harboring advanced, recurrent or metastatic USPC refractory to standard treatment modalities.

No significant financial relationships to disclose.

Predominant polarity in bipolar disorder: diagnostic implications

BACKGROUND

It has been reported that patients with bipolar disorder (BD) remain about 10 years symptomatic before the correct diagnosis is made. This fact is particularly important for patients with predominantly depressed polarity who tend to be diagnosed as suffering from unipolar major depressive disorder and treated with antidepressants. The present study was carried out to assess clinical differences between predominantly manic and depressed BD patients with a special focus on the time that patients remained undiagnosed.

METHODS

Clinical and socio-demographic characteristics were obtained from a sample of 149 euthymic bipolar outpatients. Patients were divided into depressive or manic predominance of polarity. Clinical features, number of years undiagnosed (NYU) and occupational functioning were assessed in the two groups.

RESULTS

Forty-five patients were classified as a "Depressive Polarity" whilst forty-seven were considered as "Manic Polarity". Depressive Polarity was associated with a longer delay to be diagnosed (F=14.43, df=89, p=0.001). The predominantly depressive patients tended to present a depressive onset of illness, earlier age of onset, longer duration of illness and higher number of suicide attempts than manic polarity patients.

CONCLUSION

There was a marked clinical difference between predominantly manic and depressive bipolar patients. Predominantly depressive polarity is associated with a longer delay in receiving a correct diagnosis and effective treatment which has an important impact on the management of the illness.