Prognostic factors and combined use of tocilizumab and corticosteroids in a Spanish cohort of elderly COVID-19 patients.

Coronavirus disease 2019 (COVID-19) infection in elderly patients is more aggressive and treatments have shown limited efficacy. Our objective is to describe the clinical course and to analyze the prognostic factors associated with a higher risk of mortality of a cohort of patients older than 80 years. In addition, we assess the efficacy of immunosuppressive treatments in this population. We analyzed the data from 163 patients older than 80 years admitted to our institution for COVID-19, during March and April 2020. A Lasso regression model and subsequent multivariate Cox regression were performed to select variables predictive of death. We evaluated the efficacy of immunomodulatory therapy in three cohorts using adjusted survival analysis. The mortality rate was 43%. The mean age was 85.2 years. The disease was considered severe in 76.1% of the cases. Lasso regression and multivariate Cox regression indicated that factors correlated with hospital mortality were: age (hazard ratio [HR] 1.12, 95% confidence interval [CI]: 1.03-1.22), alcohol consumption (HR 3.15, 95% CI: 1.27-7.84), CRP > 10 mg/dL (HR 2.67, 95% CI: 1.36-5.24), and oxygen support with Venturi Mask (HR 6.37, 95% CI: 2.18-18.62) or reservoir (HR 7.87, 95% CI: 3.37-18.38). Previous treatment with antiplatelets was the only protective factor (HR 0.47, 95% CI: 0.23-0.96). In the adjusted treatment efficacy analysis, we found benefit in the combined use of tocilizumab (TCZ) and corticosteroids (CS) (HR 0.09, 95% CI: 0.01-0.74) compared to standard treatment, with no benefit of CS alone (HR 0.95, 95% CI: 0.53-1.71). Hospitalized elderly patients suffer from a severe and often fatal form of COVID-19 disease. In this regard, several parameters might identify high-risk patients upon admission. Combined use of TCZ and CS could improve survival.

Update on extended treatment for venous thromboembolism.

The importance of assessing the probability of venous thromboembolism recurrence, a condition that includes deep vein thrombosis and pulmonary embolism, lies in the fact that it is the most important factor in deciding the duration of anticoagulant treatment. Risk of recurrence depends mostly on the presence of a risk factor for developing venous thromboembolism, with patients with unprovoked events being at the higher risk of recurrence. The risk of recurrence needs to be balanced with the risk of bleeding and the potential severity of these thrombotic and hemorrhagic events. In patients with an unprovoked venous thromboembolism who complete treatment for the acute (first 10 days) and post-acute phase of the disease (from day 10 to 3-6 months), the decision has to be made regarding prolonged antithrombotic therapy to prevent recurrences. The main goal of extended treatment is preventing recurrences with a safety profile in terms of bleeding risk. Many therapeutic options are now available for these patients, including antiplatelet therapy with aspirin or direct oral anticoagulants. Moreover, apixaban and rivaroxaban at prophylactic doses have demonstrated efficacy in preventing recurrences with a low risk of bleeding. Key messages Extending treatment (longer than 3-6 months) is challenging in patients with venous thromboembolism (VTE) and depend on the risk of venous thromboembolism recurrence, the bleeding risk and patient and physician preferences. Anticoagulation treatment should be stopped in patients with provoked VTE and in those with unprovoked VTE and a high bleeding risk after an initial period of 3-6 months. There are some therapeutic alternatives (including Aspirin and low dose of some NOACs) to reduce venous thromboembolism recurrence risk in patients with unprovoked VTE and a low bleeding risk for extended treatment of VTE (after an initial period of 3-6 months).

Activated human primary NK cells efficiently kill colorectal cancer cells in 3D spheroid cultures irrespectively of the level of PD-L1 expression.

Haploidentical Natural Killer (NK) cells have been shown as an effective and safe alternative for the treatment of haematological malignancies with poor prognosis for which traditional therapies are ineffective. In contrast to haematological cancer cells, that mainly grow as single suspension cells, solid carcinomas are characterised by a tridimensional (3D) architecture that provide specific surviving advantages and resistance against chemo- and radiotherapy. However, little is known about the impact of 3D growth on solid cancer immunotherapy especially adoptive NK cell transfer. We have recently developed a protocol to activate ex vivo human primary NK cells using B lymphoblastic cell lines, which generates NK cells able to overcome chemoresistance in haematological cancer cells. Here we have analysed the activity of these allogeneic NK cells against colorectal (CRC) human cell lines growing in 3D spheroid culture and correlated with the expression of some of the main ligands regulating NK cell activity. Our results indicate that activated NK cells efficiently kill colorectal tumour cell spheroids in both 2D and 3D cultures. Notably, although 3D CRC cell cultures favoured the expression of the inhibitory immune checkpoint PD-L1, it did not correlate with increased resistance to NK cells. Finally, we have analysed in detail the infiltration of NK cells in 3D spheroids by microscopy and found that at low NK cell density, cell death is not observed although NK cells are able to infiltrate into the spheroid. In contrast, higher densities promote tumoural cell death before infiltration can be detected. These findings show that highly dense activated human primary NK cells efficiently kill colorectal carcinoma cells growing in 3D cultures independently of PD-L1 expression and suggest that the use of allogeneic activated NK cells could be beneficial for the treatment of colorectal carcinoma.

Evaluating Interaction of Cord Blood Hematopoietic Stem/Progenitor Cells with Functionally Integrated Three-Dimensional Microenvironments.

Despite advances in ex vivo expansion of cord blood-derived hematopoietic stem/progenitor cells (CB-HSPC), challenges still remain regarding the ability to obtain, from a single unit, sufficient numbers of cells to treat an adolescent or adult patient. We and others have shown that CB-HSPC can be expanded ex vivo in two-dimensional (2D) cultures, but the absolute percentage of the more primitive stem cells decreases with time. During development, the fetal liver is the main site of HSPC expansion. Therefore, here we investigated, in vitro, the outcome of interactions of primitive HSPC with surrogate fetal liver environments. We compared bioengineered liver constructs made from a natural three-dimensional-liver-extracellular-matrix (3D-ECM) seeded with hepatoblasts, fetal liver-derived (LvSt), or bone marrow-derived stromal cells, to their respective 2D culture counterparts. We showed that the inclusion of cellular components within the 3D-ECM scaffolds was necessary for maintenance of HSPC viability in culture, and that irrespective of the microenvironment used, the 3D-ECM structures led to the maintenance of a more primitive subpopulation of HSPC, as determined by flow cytometry and colony forming assays. In addition, we showed that the timing and extent of expansion depends upon the biological component used, with LvSt providing the optimal balance between preservation of primitive CB HSPC and cellular differentiation. Stem Cells Translational Medicine 2018;7:271-282.

Glioblastoma on a microfluidic chip: Generating pseudopalisades and enhancing aggressiveness through blood vessel obstruction events.

Background: Glioblastoma (GBM) is one of the most lethal tumor types. Hypercellular regions, named pseudopalisades, are characteristic in these tumors and have been hypothesized to be waves of migrating glioblastoma cells. These "waves" of cells are thought to be induced by oxygen and nutrient depletion caused by tumor-induced blood vessel occlusion. Although the universal presence of these structures in GBM tumors suggests that they may play an instrumental role in GBM's spread and invasion, the recreation of these structures in vitro has remained challenging. Methods: Here we present a new microfluidic model of GBM that mimics the dynamics of pseudopalisade formation. To do this, we embedded U-251 MG cells within a collagen hydrogel in a custom-designed microfluidic device. By controlling the medium flow through lateral microchannels, we can mimic and control blood-vessel obstruction events associated with this disease. Results: Through the use of this new system, we show that nutrient and oxygen starvation triggers a strong migratory process leading to pseudopalisade generation in vitro. These results validate the hypothesis of pseudopalisade formation and show an excellent agreement with a systems-biology model based on a hypoxia-driven phenomenon. Conclusions: This paper shows the potential of microfluidic devices as advanced artificial systems capable of modeling in vivo nutrient and oxygen gradients during tumor evolution.