Can a 5-to-90-day Mortality Predictor Perform Consistently Across Time and Equitably Across Populations?

Advance care planning (ACP) facilitates end-of-life care, yet many die without it. Timely and accurate mortality prediction may encourage ACP. However, performance of predictors typically differs among sub-populations (e.g., rural vs. urban) and worsens over time ("concept drift"). Therefore, we assessed performance equity and consistency for a novel 5-to-90-day mortality predictor across various demographies, geographies, and timeframes (n = 76,812 total encounters). Predictions were made for the first day of included adult inpatient admissions on a retrospective dataset. AUC-PR remained at 29% both pre-COVID (throughout 2018) and during COVID (8 months in 2021). Pre-COVID-19 recall and precision were 58% and 25% respectively at the 12.5% certainty cutoff, and 12% and 44% at the 37.5% cutoff. During COVID-19, recall and precision were 59% and 26% at the 12.5% cutoff, and 11% and 43% at the 37.5% cutoff. Pre-COVID, compared to the overall population, recall was lower at the 12.5% cutoff in the White, non-Hispanic subgroup and at both cutoffs in the rural subgroup. During COVID-19, precision at the 12.5% cutoff was lower than that of the overall population for the non-White and non-White female subgroups. No other significant differences were seen between subgroups and the corresponding overall population. Overall performance during COVID was unchanged from pre-pandemic performance. Although some comparisons (especially precision at the 37.5% cutoff) were underpowered, precision at the 12.5% cutoff was equitable across most demographies, regardless of the pandemic. Mortality prediction to prioritize ACP conversations can be provided consistently and equitably across many studied timeframes and sub-populations.

Corrigendum: Extracorporeal Shock Wave Therapy Enhances the In Vitro Metabolic Activity and Differentiation of Equine Umbilical Cord Blood Mesenchymal Stromal Cells.

[This corrects the article DOI: 10.3389/fvets.2020.554306.].

Steps Toward Standardized In Vitro Assessment of Immunomodulatory Equine Mesenchymal Stromal Cells Before Clinical Application.

Inflammation-associated disorders are significant causes of morbidity in horses. Equine single-donor mesenchymal stromal cells (sdMSCs) hold promise as cell-therapy candidates due to their secretory nonprogenitor functions. This has been demonstrated by mononuclear cell suppression assays (MSAs) showing that sdMSCs are blood mononuclear cell (BMC) suppressive in vitro. sdMSCs derived from umbilical cord blood are of clinical interest due to their ease of procurement, multipotency, and immunomodulatory ability. Due to the inherent donor-to-donor heterogeneity of MSCs, the development of robust and easily deployable methods of potency assessment is critical for improving MSCs' predictability in treating inflammatory diseases. This study focuses on the development of robust in vitro potency assays and the assessment of potential sdMSC therapeutic end products generated from pooled sdMSCs (pMSCs). We hypothesized that, compared to MSA using only one donor, MSA using pooled BMCs (pBMCs) is a more robust sdMSC potency assay due to reduced donor BMC heterogeneity. pBMCs were generated by pooling equine BMCs isolated from peripheral blood of five donors in equal ratios. pBMCs were labeled with carboxyfluorescein succinimidyl ester (CFSE) and stored in liquid nitrogen until use. Similarly, pooling sdMSCs from multiple equine donors in equal ratios generated pMSCs. sdMSC cultures were assessed with pBMCs in MSA using Bromodeoxyuridine ELISA and CFSE. Proliferation assessment of BMCs from individual donors revealed varied responses to concanavalin A (ConA) stimulation. MSA using BMCs from single donors further demonstrated BMC donor variability. Utilizing this assay, we have also found that the immunosuppressive potencies of pMSCs are at least equal, if not more, than the calculated mean of individual cultures. MSA based on pBMCs provides a consistent and reproducible equine sdMSC potency assay. This knowledge could be used in production monitoring of cellular potency and as release criteria before clinical use.

Extracorporeal Shock Wave Therapy Enhances the In Vitro Metabolic Activity and Differentiation of Equine Umbilical Cord Blood Mesenchymal Stromal Cells.

Extracorporeal shock wave therapy (ESWT) has been shown to induce different biological effects on a variety of cells, including regulation and stimulation of their function and metabolism. ESWT can promote different biological responses such as proliferation, migration, and regenerations of cells. Recent studies have shown that mesenchymal stromal cells (MSCs) secrete factors that enhance the regeneration of tissues, stimulate proliferation and differentiation of cells, and decrease inflammatory and immune reactions. Clinically, the combination of these two therapies has been used as a treatment for tendon and ligament lesions in horses; however, there is no scientific evidence supporting this combination of therapies in vivo. Therefore, the objectives of the study were to evaluate the effects of ESWT on equine umbilical cord blood mesenchymal stromal cells (CB-MSCs) proliferative, metabolic, migrative, differentiation, and immunomodulatory properties in vitro. Three equine CB-MSC cultures from independent donors were treated using an electrohydraulic shock wave generator attached to a water bath. All experiments were performed as triplicates. Proliferation, viability, migration and immunomodulatory properties of the cells were evaluated. Equine CB-MSCs were induced to evaluate their trilineage differentiation potential. ESWT treated cells had increased metabolic activity, showed positive adipogenic, osteogenic, and chondrogenic differentiation, and showed higher potential for differentiation toward the adipogenic and osteogenic cell fates. ESWT treated cells showed similar immunomodulatory properties to none-ESWT treated cells. Equine CB-MSCs are responsive to ESWT treatment and showed increased metabolic, adipogenic and osteogenic activity, but unaltered immunosuppressive properties. In vivo studies are warranted to determine if synergistic effects occur in the treatment of musculoskeletal injuries if ESWT and equine CB-MSC therapies are combined.

The Importance of Dosing, Timing, and (in)Activation of Adipose Tissue-Derived Mesenchymal Stromal Cells on Their Immunomodulatory Effects.

Mesenchymal stromal cells (MSCs) are attractive candidates for immunomodulatory cell therapy. However, it remains unknown how far therapeutic efficacy and potency are dependent on the dosage and activity of the MSCs. We previously observed that infusion of MSCs leads to rapid and transient changes in cytokine expression in blood, lung, and liver. In the present study, increasing doses of syngeneic adipose tissue-derived MSCs were infused in healthy mice and systemic changes in G-CSF, IL6, IL-10, and CXCL5 were detected 2 h after administration of 3 × 105 MSCs per animal, but not at lower doses. In lung and liver tissue, dose-dependent effects of MSCs on cytokine mRNA expression levels were detected from doses as low as 3 × 103 MSCs. Infusion of secretome-deficient or IFNγ-activated MSCs in healthy mice had similar effects on systemic cytokine levels as control MSCs, suggesting that in vivo at least the initial systemic effect of MSC administration is independent of the level of activity of MSCs, but depends on the response of host cells to MSCs. The results of this study reveal a rapid dose-dependent effect of MSCs and stress the important role of host cells in MSC treatment. This knowledge contributes to the design of rational MSC trials and to the quest for clinical efficacy of MSC therapy.

Equine Cord Blood Mesenchymal Stromal Cells Have Greater Differentiation and Similar Immunosuppressive Potential to Cord Tissue Mesenchymal Stromal Cells.

Mesenchymal stromal cells (MSCs) are the most common cell population studied for therapeutic use in veterinary medicine. MSCs obtained from neonatal sources such as umbilical cord tissue (CT-MSCs) or cord blood (CB-MSCs) are appealing due to the non-invasive nature of procurement and the time allowed for characterization of cells before use. However, it remains unclear as to whether CB- or CT-MSCs have equivalent progenitor and non-progenitor functions. CB-MSCs have been shown to have superior chondrogenic potential to MSCs from other sources, whereas their immunomodulatory capacity does not seem to vary significantly. Using equine CB-MSCs and CT-MSCs from the same donors, we hypothesized that MSCs from both sources would have a similar immunophenotype, that CB-MSCs would be more amenable to differentiation, and that they can equally suppress lymphocyte proliferation. We evaluated cells from both sources for "classic" equine MSC markers CD90, CD105, CD29, and CD44, as well as pericyte markers CD146, NG2, and α-SMA. Contrary to our hypothesis, CB-MSCs showed mid- to high expression of pericyte surface markers CD146 and NG2, whereas expression in CT-MSCs was absent. On trilineage differentiation, CB-MSCs were more osteogenic and chondrogenic based on alkaline phosphatase activity and glycosaminoglycan content, respectively. Finally, using a mononuclear cell (MNC) suppression assay, we determined that both CB-MSCs and CT-MSCs are capable of suppressing stimulated MNC proliferation to a similar degree. We have determined that the choice of MSC tissue source should be made with the intended application in mind. This appears to be particularly relevant if pursuing a progenitor-based treatment strategy.