Cross-sectional study evaluating the association of haemophilia-related distress and clinically relevant outcomes.

INTRODUCTION: In chronic diseases, disease-related distress can impact disease outcomes. Distress and haemophilia-related distress has been demonstrated in people with haemophilia (PwH). The association of haemophilia-related distress on disease outcomes among PwH is unknown. AIM: To study the association of haemophilia-related distress with haemophilia specific outcomes, including adherence to prophylactic therapy, the presence of a target joint, healthcare utilization and work-impairment. METHODS: In a cross-sectional study, adults with haemophilia A or B were enrolled in a study to validate the haemophilia-related distress questionnaire (HRDq). In this planned analysis, univariate and multivariate associations between the HRDq total score and disease outcomes were explored. RESULTS: The 114 participants in this analysis were male, mostly with haemophilia A (92%) and severe disease (52%) with a median age of 31.9 years. On univariate analysis, HRDq total score (5-point change) was associated with the presence of a target joint (P = .002), high healthcare utilization (P = .011), poor adherence (P = .033) and work-impairment (P ≤ .001). After adjustment for age, race, severity and other potential confounders, adherence (aß 0.33, 95% CI .17, .49) and work-impairment (aß 4.69, 95% CI 3.27-6.1) remained statistically significantly associated with HRDq total score. CONCLUSION: Haemophilia-related distress is associated with poor adherence to factor prophylaxis and work-impairment. The direction of the association (causation) is yet to be determined and requires future study.

CD45RB Status of CD8+ T Cell Memory Defines T Cell Receptor Affinity and Persistence.

The identity of CD45 isoforms on the T cell surface changes following the activation of naive T cells and impacts intracellular signaling. In this study, we find that the anti-viral memory CD8+ T pool is unexpectedly comprised of both CD45RBhi and CD45RBlo populations. Relative to CD45RBlo memory T cells, CD45RBhi memory T cells have lower affinity and display greater clonal diversity, as well as a persistent CD27hi phenotype. The CD45RBhi memory population displays a homeostatic survival advantage in vivo relative to CD45RBlo memory, and long-lived high-affinity cells that persisted long term convert from CD45RBlo to CD45RBhi. Human CD45RO+ memory is comprised of both CD45RBhi and CD45RBlo populations with distinct phenotypes, and antigen-specific memory to two viruses is predominantly CD45RBhi. These data demonstrate that CD45RB status is distinct from the conventional central/effector T cell memory classification and has potential utility for monitoring and characterizing pathogen-specific CD8+ T cell responses.

Enhanced Requirement for TNFR2 in Graft Rejection Mediated by Low-Affinity Memory CD8+ T Cells during Heterologous Immunity.

The affinity of a TCR binding to peptide:MHC profoundly impacts the phenotype and function of effector and memory cell differentiation. Little is known about the effect of low-affinity priming on memory cell generation and function, which is particularly important in heterologous immunity, when microbe-specific T cells cross-react with allogeneic Ag and mediate graft rejection. We found that low-affinity-primed memory CD8(+) T cells produced high levels of TNF ex vivo in response to heterologous rechallenge compared with high-affinity-primed memory T cells. Low-affinity secondary effectors significantly upregulated TNFR2 on the cell surface and contained a higher frequency of TNFR2(hi) proliferating cells. Low-affinity-primed secondary effectors concurrently downregulated TNF production. Importantly, blockade of TNFR2 attenuated graft rejection in low- but not high-affinity-primed animals. These data establish a functional connection between TNF signaling and TCR-priming affinity and have implications for the immunomodulation of pathogenic T cell responses during transplantation.