Sarcopenia risk and associated factors among Chinese community-dwelling older adults living alone.

Sarcopenia, defined as a progressive loss of muscle mass and reduced muscle strength and functional capacity, is common among older adults. This study aimed to assess the proportion of people at risk of sarcopenia and probable sarcopenia among Chinese community-dwelling older adults living alone and to identify the associated factors. A total of 390 older adults were included in this study. Sarcopenia and probable sarcopenia were defined according to the criteria of the Asian Working Group for Sarcopenia 2019. Data on socio-demographic characteristics, health status, health behaviours and lifestyle characteristics, nutritional status, physical activity level, and depressive symptoms were collected. The association between these characteristics and sarcopenia risk was analysed using a multivariate ordinal logistic regression. The proportion of subjects at risk of sarcopenia and probable sarcopenia was found to be 57.7% and 30%, respectively. Older age, being malnourished and being at risk of malnutrition were significantly associated with sarcopenia risk. Being educated to secondary level or above, being overweight or obese and higher physical activity level were associated with decreased sarcopenia risk. Our results showed that older adults living alone were at high risk of developing sarcopenia and probable sarcopenia. These results emphasise the urgent need to initiate aggressive screening and holistic lifestyle therapeutic intervention strategies for this high-risk population.

Mechanistic biomarkers for clinical decision making in rheumatic diseases.

The use of biomarkers is becoming increasingly intrinsic to the practice of medicine and holds great promise for transforming the practice of rheumatology. Biomarkers have the potential to aid clinical diagnosis when symptoms are present or to provide a means of detecting early signs of disease when they are not. Some biomarkers can serve as early surrogates of eventual clinical outcomes or guide therapeutic decision making by enabling identification of individuals likely to respond to a specific therapy. Using biomarkers might reduce the costs of drug development by enabling individuals most likely to respond to be enrolled in clinical trials, thereby minimizing the number of participants required. In this Review, we discuss the current use and the potential of biomarkers in rheumatology and in select fields at the forefront of biomarker research. We emphasize the value of different types of biomarkers, addressing the concept of 'actionable' biomarkers, which can be used to guide clinical decision making, and 'mechanistic' biomarkers, a subtype of actionable biomarker that is embedded in disease pathogenesis and, therefore, represents a potentially superior biomarker. We provide examples of actionable and mechanistic biomarkers currently available, and discuss how development of such biomarkers could revolutionize clinical practice and drug development.

Regulation of human Th9 differentiation by type I interferons and IL-21.

Interleukin (IL)-9-producing CD4(+) T cells are a novel subset of T helper (Th) cells that develops independently of the Th1, Th2, Th17 and regulatory T-cell lineages. Similar to the murine model, transforming growth factor (TGF)-beta and IL-4 directed human naive CD4(+) T cells to produce IL-9. Whereas IL-4 suppressed TGF-beta-induced Foxp3 expression, TGF-beta failed to inhibit IL-4-mediated upregulation of the Th2 transcription factor GATA-3. Addition of IL-1 beta, IL-6, IL-10, interferon (IFN)-alpha, IFN-beta or IL-21 to Th9-polarizing conditions augmented Th9 differentiation, while the Th1-associated cytokines IFN-gamma and IL-27 partially suppressed IL-9 production. Given that T cells are a primary source of IL-21, IL-21 expression was analyzed under Th9-polarizing conditions in the context of inflammatory cytokines. Surprisingly, type I IFNs induced elevated levels of IL-21, and blockade of IL-21 abrogated their ability to enhance Th9 differentiation. Taken together, these data indicate a complex cytokine network in the regulation of human IL-9-producing CD4(+) T cells.

HIT: a versatile proteomics platform for multianalyte phenotyping of cytokines, intracellular proteins and surface molecules.

We have developed a multianalyte fluid-phase protein array technology termed high-throughput immunophenotyping using transcription (HIT). This method employs a panel of monoclonal antibodies, each tagged with a unique oligonucleotide sequence that serves as a molecular bar code. After staining a sample, T7 polymerase amplifies the tags, which are then hybridized to a DNA microarray for indirect measurement of each analyte. Although there are many potential applications for this technology, here we report its suitability for profiling cytokines, intracellular molecules and cell surface markers. Using HIT, we profiled 90 surface markers on human naive T helper cells activated in vitro. The markers identified in this screen are consistent with previously described activation markers and were validated by flow cytometry. Additionally, a HIT screen of surface markers expressed on T helper cells activated in the presence of transforming growth factor-beta identified downregulation of CD26 in these cells. HIT arrays are an ideal platform for rapidly identifying markers for further characterization and therapeutic intervention.