Evaluation of Bone Remodeling in Hemodialysis Patients: Serum Biochemistry, Circulating Cytokines and Bone Histomorphometry

BACKGROUND: To optimize the noninvasive evaluation of bone remodeling, we evaluated, besides routine serum markers, serum levels of several cytokines involved in bone turnover. METHODS: A transiliac bone biopsy was performed in 47 hemodialysis patients. Serum levels of intact parathyroid hormone (iPTH; 1-84), total alkaline phosphatases (tAP), calcium, phosphate and aluminum (Al) were measured. Circulating levels of interleukin-6 (IL-6), IL-1 receptor antagonist (IL-1Ra) and soluble IL-6 receptor (sIL-6r) were determined using ELISA. Circulating IL-1beta, IL-6, IL-8, IL-10, IL-12p70 and tumor necrosis factor-alpha (TNF-alpha) were simultaneously quantified by flow cytometric immunoassay. RESULTS: Patients with low/normal bone formation rate (L/N-BFR) had significantly lower serum iPTH (p<0.001) and tAP (p<0.008) and significantly higher Al (p<0.025) than patients with high BFR. Serum calcium and phosphorus, however, did not differ (p=NS). An iPTH >300 pg/mL in association with tAP >120 U/L showed low sensitivity (58.8%) and low negative predictive value (44.0%) for the diagnosis of high BFR disease. An iPTH <300 pg/mL in association with normal or low tAP, <120 U/L, was associated with low sensitivity (66.7%) but high specificity (97.1%) for the diagnosis of L/N-BFR. Serum IL-1, IL-6, IL-12p70 and TNF-alpha were positively correlated with BFR, serum IL1-Ra and IL-10 with bone area, and by multiple regression analysis, tAP and IL-6 were independently predictive of BFR. CONCLUSIONS: Significant associations were found between several circulating cytokines and bone histomorphometry in dialysis patients. The usefulness of these determinations in the noninvasive evaluation of bone remodeling needs to be confirmed in larger dialysis populations.

Psychosocial Determinants of Quality of Life 6 Months After Transplantation: Longitudinal Prospective Study

OBJECTIVES: We sought to investigate the psychosocial determinants of quality of life at 6 months after transplantation. METHODS: A sample of liver transplant candidates (n = 60), composed of consecutive patients (25% with familial amyloid polyneuropathy [FAP]) attending outpatient clinics was assessed in the pretransplant period using the Neo Five Factor Inventory, Hospital Anxiety and depression Scale (HADS), Brief COPE, and SF-36, a quality-of-life, self-rating questionnaire. Six months after transplantation, these patients were assessed by means of the SF-36. RESULTS: Psychosocial predictors where found by means of multiple regression analysis. The physical component of quality of life at 6 months after transplantation was determined based upon coping strategies and physical quality of life in the pretransplant period (this model explained 32% of variance). The mental component at 6 months after transplantation was determined by depression in the pretransplant period and by clinical diagnoses of patients. Because FAP patients show a lower mental component of quality of life, this diagnosis explained 25% of the variance. CONCLUSIONS: Our findings suggested that coping strategies and depression measured in the pretransplant period are important determinants of quality of life at 6 months after liver transplantation.