Expression of HLA-DR antigens by thyroid cells: the effect of Graves' IgG

We have investigated factors which influence HLA-DR expression on thyroid cells. While bTSH (100 mU/ml) did not enhance HLA-DR expression, it increased when brought about by IFN-gamma. Graves' IgG showed a dose-dependent (0.1-2 mg/ml) increase in DR expression and at a concentration of 2 mg/ml prolonged the time for which DR was expressed. The pathway of DR induction by Graves' IgG apparently differs from that by IFN-gamma. The humoral response in Graves' disease, by inducing DR expression, may be instrumental in propagating thyroid specific autoimmunity.     

Psychosocial risk and protective factors for depression in the dialysis population: a systematic review and meta-regression analysis

Objective

Research into the association between psychosocial factors and depression in End-Stage Renal Disease (ESRD) has expanded considerably in recent years identifying a range of factors that may act as important risk and protective factors of depression for this population. The present study provides the first systematic review and meta-analysis of this body of research.

Methods

Published studies reporting associations between any psychosocial factor and depression were identified and retrieved from Medline, Embase, and PsycINFO, by applying optimised search strategies. Mean effect sizes were calculated for the associations across five psychosocial constructs (social support, personality attributes, cognitive appraisal, coping process, stress/stressor). Multiple hierarchical meta-regression analysis was applied to examine the moderating effects of methodological and substantive factors on the strength of the observed associations.

Results

57 studies covering 58 independent samples with 5956 participants were identified, resulting in 246 effect sizes of the association between a range of psychosocial factors and depression. The overall mean effect size (Pearsons correlation coefficient) of the association between psychosocial factor and depression was 0.36. The effect sizes between the five psychosocial constructs and depression ranged from medium (0.27) to large levels (0.46) with personality attributes (0.46) and cognitive appraisal (0.46) having the largest effect sizes. In the meta-regression analyses, identified demographic (gender, age, location of study) and treatment (type of dialysis) characteristics moderated the strength of the associations with depression.

Conclusion

The current analysis documents a moderate to large association between the presence of psychosocial risk factors and depression in ESRD.     

Studying psychosocial adaptation to end-stage renal disease: the proximal-distal model of health-related outcomes as a base model

Objective

Studying psychosocial adaptation in end-stage renal disease (ESRD) is increasingly important, as it may explain the variability in health outcomes unaccounted for by clinical factors. The Brenner et al. proximal-distal model of health-related outcomes provides a theoretical foundation for understanding psychosocial adaptation and integrating health outcomes, clinical, and psychosocial factors (Brenner MH, Curbow B, Legro MW. The proximal-distal continuum of multiple health outcome measures: the case of cataract surgery. Med Care. 1995;33(4 Suppl):AS236-44). This study aims to empirically validate the proximal-distal model in the dialysis population and examine the impact of psychosocial factors on the model.

Methods

A cross-sectional observational study was conducted with a sample of long-term dialysis patients (n=201). Eleven factors: quality of life (QoL), depression, positive affect, comorbidity, symptoms, physical functioning, disease accommodation, loss, self-efficacy, illness acceptance, and social support were measured by standardized psychometric scales. A three-month average of hemoglobin was used. Latent composite structural equation modeling was used to examine the models.

Results

The proximal-distal model with slight modification was supported by fit statistics [χ²=16.04, df=13, P=.25, root mean square error of approximation (RMSEA)=0.024], indicating that the impact of clinical factors on QoL is mediated through a range of functional and psychological factors, except for hemoglobin which impacts directly on QoL. The model with additional psychosocial factors was also supported by fit statistics (χ²=43.59, df=41, P=.36, RMSEA=0.018). These additional factors mainly impact on symptom status, psychological states, and QoL components of the model.

Conclusion

The present study supported the proximal-distal model in the dialysis population and demonstrated the considerable impact of psychosocial factors on the model. The proximal-distal model plus psychosocial factors as a biopsychosocial model can be applied to studying psychosocial adaptation in ESRD.