Psychometric properties and observational data for COVID-19 Yorkshire Rehabilitation Scale (C19-YRSm) for post-COVID-19 syndrome.

BACKGROUND: The recently developed modified COVID-19 (coronavirus of 2019) Yorkshire Rehabilitation Scale (C19-YRSm) captures comprehensive biopsychosocial components of WHO's International Classification of Functioning, Disability, and Health related to the Long Covid or post-COVID syndrome. The scale response categories on C19-YRSm were done post hoc on data collected from the original version of C19-YRS. AIM: To evaluate the C19-YRSm scale using reliability and validity measures. DESIGN: Prospective, observational study. METHODS: The study includes 369 patients (clinical group) and 426 subjects of the general population (control group) and captures their post-COVID-19 symptoms. In addition, the reliability of C19-YRSm was estimated by Cronbach's alpha coefficients of internal consistency and inter-item correlations for subscales ('Symptom severity, Functional disability, and Other symptoms'). Convergent validity was established using correlations between C19-YRSm and Fatigue Severity Scale (FSS). The incremental validity of C19-YRSm was measured by introducing a hierarchical regression model using the C19-YRSm 'Overall health' subscale and FSS as criterion variables. RESULTS: C19-YRSm subscales have excellent internal consistencies (Cronbach's α value 0.81-0.96) and acceptable inter-item correlations (r value 0.23-0.79). Hereafter, the convergent validity of the C19-YRSm is good due to significant correlations between C19-YRSm subscales and FSS and C19-YRSm subscales. Finally, the hierarchical regression analysis supported consistent evidence for the incremental validity of the C19-YRSm subscales. CONCLUSION: C19-YRSm is a reliable and valid self-assessment scale for the assessment of post-COVID-19 syndrome.

Key role for CD4 T cells during mixed antibody-mediated rejection of renal allografts.

We utilized mouse models to elucidate the immunologic mechanisms of functional graft loss during mixed antibody-mediated rejection of renal allografts (mixed AMR), in which humoral and cellular responses to the graft occur concomitantly. Although the majority of T cells in the graft at the time of rejection were CD8 T cells with only a minor population of CD4 T cells, depletion of CD4 but not CD8 cells prevented acute graft loss during mixed AMR. CD4 depletion eliminated antidonor alloantibodies and conferred protection from destruction of renal allografts. ELISPOT revealed that CD4 T effectors responded to donor alloantigens by both the direct and indirect pathways of allorecognition. In transfer studies, CD4 T effectors primed to donor alloantigens were highly effective at promoting acute graft dysfunction, and exhibited the attributes of effector T cells. Laser capture microdissection and confirmatory immunostaining studies revealed that CD4 T cells infiltrating the graft produced effector molecules with graft destructive potential. Bioluminescent imaging confirmed that CD4 T effectors traffic to the graft site in immune replete hosts. These data document that host CD4 T cells can promote acute dysfunction of renal allografts by directly mediating graft injury in addition to facilitating antidonor alloantibody responses.