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Background: Little is known about changes in parathyroid hormone (PTH), calcium and phosphorous levels after parathyroidectomy in hemodialysis patients. We studied the effects of parathyroidectomy on these biochemical values in a large cohort of patients receiving maintenance hemodialysis., Methods: This retrospective cohort study included patients identified in both the United States Renal Data System and the database of a large dialysis organization who underwent parathyroidectomy in 2007-09, were aged ≥ 18 years, had Medicare Parts A and B as primary payer and had received hemodialysis for ≥ 1 year pre-parathyroidectomy. Descriptive statistics were calculated for continuous variables; categorical variables were used to characterize the population and evaluate monthly laboratory and medication use; median values were calculated for laboratory measures., Results: Among 1402 parathyroidectomy patients, mean age was 48.9 years, 52.4% were males, 58.8% were African American and mean dialysis duration was 7.5 years. Median PTH levels increased over the year before parathyroidectomy from 1039 to 1661 pg/mL and decreased afterward to 98 pg/mL at 1 month; levels remained ≥ 897 pg/mL for 10% of patients. Median calcium levels fell from 9.6 mg/dL before to 7.9 mg/dL 1 month after parathyroidectomy; levels were ≤ 7.1 mg/dL for 25% and remained ≤ 7.2 mg/dL for the lowest 25% at 3 months. Median phosphorous level was 6.8 mg/dL immediately before parathyroidectomy, decreased to 3.8 mg/dL immediately after and reached 5.8 mg/dL at 1 year., Conclusions: While PTH levels dropped after parathyroidectomy for most patients, surgery was sometimes ineffective in reducing levels and sometimes led to over-suppression. Hypocalcemia could be profound and long lasting, suggesting the need for prolonged vigilance., (© The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Background: It is important to identify an easily defined subset of patients at increased risk of adverse clinical outcomes associated with mineral and bone disorder (MBD) biomarkers (parathyroid hormone, calcium and phosphate)., Methods: Observational cohort study of 26 221 prevalent hemodialysis patients in Davita clinics as of 31 August 2005 and followed up until 31 December 2006 (16 months). Predictors were 12 possible definitions of 'clinically important' MBD based on all 3 biomarkers, and 18 alternative definitions based on only 1 or 2 biomarkers. Events were death alone and a composite of cardiovascular hospitalization or death. Excess events were calculated based on a multivariate Cox model using 5224 patients in target for all MBD biomarkers and applied to 20 997 patients out of target for at least one biomarker. Excess events attributable to MBD were estimated by subtracting the multivariate model-derived predicted number from the actual number. Outcomes were the proportion of excess events attributable to MBD captured by each definition (threshold ≥70%) and the reduction in the population size considered to have clinically important MBD (threshold ≥30%). The excess fraction was excess events divided by actual events., Results: Patients with more biochemical markers out of target tended to be younger, black and have longer times since starting dialysis. The excess fraction associated with MBD ranged from ∼10 to 26% depending on the clinical endpoint and definition. The only definition to meet the thresholds required at least two of the three MBD biomarkers to be out of target (high or low). It captured 82% of excess composite endpoints and 74% of excess deaths and reduced the at-risk population by 46%., Conclusions: Patients with at least two of three MBD biomarkers out of target represent a subgroup of patients at elevated risk of adverse clinical events., (© The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA.)

Background: Sensitization to human leukocyte antigen (HLA) from red blood cell (RBC) transfusion is poorly quantified and is based on outdated, insensitive methods. The objective was to evaluate the effect of transfusion on the breadth, magnitude and specificity of HLA antibody formation using sensitive and specific methods., Methods: Transfusion, demographic and clinical data from the US Renal Data System were obtained for patients on dialysis awaiting primary kidney transplant who had ≥ 2 HLA antibody measurements using the Luminex single-antigen bead assay. One cohort included patients with a transfusion (n = 50) between two antibody measurements matched with up to four nontransfused patients (n = 155) by age, sex, race and vintage (time on dialysis). A second crossover cohort (n = 25) included patients with multiple antibody measurements before and after transfusion. We studied changes in HLA antibody mean fluorescence intensity (MFI) and calculated panel reactive antibody (cPRA)., Results: In the matched cohort, 10 of 50 (20%) transfused versus 6 of 155 (4%) nontransfused patients had a ≥ 10 HLA antibodies increase of >3000 MFI (P = 0.0006); 6 of 50 (12%) transfused patients had a ≥ 30 antibodies increase (P = 0.0007). In the crossover cohort, the number of HLA antibodies increasing >1000 and >3000 MFI was higher in the transfused versus the control period, P = 0.03 and P = 0.008, respectively. Using a ≥ 3000 MFI threshold, cPRA significantly increased in both matched (P = 0.01) and crossover (P = 0.002) transfused patients., Conclusions: Among prospective primary kidney transplant recipients, RBC transfusion results in clinically significant increases in HLA antibody strength and breadth, which adversely affect the opportunity for future transplant.

Background: There is limited data available on the use of red blood cell (RBC) transfusions in younger chronic kidney disease patients not on dialysis (CKD-ND), for whom the consequences of developing antibodies to foreign antigens (allosensitization) may be particularly relevant., Methods: We used the Ingenix medical claims database, comprising data on ∼40 million commercially insured US individuals, to identify annual (2002-08) cohorts of patients 18-64 years of age with newly diagnosed CKD. We followed each cohort for 1 year to estimate RBC transfusion rates and used Cox proportional hazards regression to identify patient characteristics associated with time to first transfusion., Results: We identified 120 790 newly diagnosed CKD patients for the years 2002-08; 54% were 50-64 years of age. Overall, the transfusion rate was 2.64/100 person-years (PYs) (95% CI: 2.52-2.77). Rates were higher among those with diagnosed anemia [9.80/100 PYs (95% CI: 9.31-10.3)] and among those who progressed to end-stage renal disease (ESRD) [28.0/100 PYs (95% CI: 23.7-33.0)]. For those progressing to ESRD, transfusion rates more than doubled between 2002 and 2008. Of the factors evaluated, transfusion history and the presence of heart failure and diabetes were most strongly associated with a receipt of a transfusion., Conclusions: RBC transfusions are relatively common and on the rise among younger CKD-ND patients who are anemic and progress to ESRD. Efforts to decrease the use of transfusions may be important for potential transplant candidates who progress to ESRD.

Background: The excess morbidity and mortality related to catheter utilization at and immediately following dialysis initiation may simply be a proxy for poor prognosis. We examined hospitalization burden related to vascular access (VA) type among incident patients who received some predialysis care., Methods: We identified a random sample of incident US Dialysis Outcomes and Practice Patterns Study hemodialysis patients (1996-2004) who reported predialysis nephrologist care. VA utilization was assessed at baseline and throughout the first 6 months on dialysis. Poisson regression was used to estimate the risk of all-cause and cause-specific hospitalizations during the first 6 months., Results: Among 2635 incident patients, 60% were dialyzing with a catheter, 22% with a graft and 18% with a fistula at baseline. Compared to fistulae, baseline catheter use was associated with an increased risk of all-cause hospitalization [adjusted relative risk (RR) = 1.30, 95% confidence interval (CI): 1.09-1.54] and graft use was not (RR = 1.07, 95% CI: 0.89-1.28). Allowing for VA changes over time, the risk of catheter versus fistula use was more pronounced (RR = 1.72, 95% CI: 1.42-2.08) and increased slightly for graft use (RR = 1.15, 95% CI: 0.94-1.41). Baseline catheter use was most strongly related to infection-related (RR = 1.47, 95% CI: 0.92-2.36) and VA-related hospitalizations (RR = 1.49, 95% CI: 1.06-2.11). These effects were further strengthened when VA use was allowed to vary over time (RR = 2.31, 95% CI: 1.48-3.61 and RR = 3.10, 95% CI: 1.95-4.91, respectively). A similar pattern was noted for VA-related hospitalizations with graft use. Discussion. Among potentially healthier incident patients, hospitalization risk, particularly infection and VA-related, was highest for patients dialyzing with a catheter at initiation and throughout follow-up, providing further support to clinical practice recommendations to minimize catheter placement.

Background: Recent clinical trials in cancer patients treated with erythropoiesis-stimulating agents (ESAs) and in CKD patients treated to haemoglobin (Hb) targets above the labeled range of 10-12 g/dL with ESAs raised safety concerns regarding ESA therapy. Subsequently, product labeling was revised including addition of a black-box warning and removal of many quality of life claims not supported by current standards, and there were changes in reimbursement and anaemia guidelines. The extent to which these events influenced ESA dosing and Hb levels in patients with chronic kidney disease not on dialysis (CKD-NOD) is not known., Methods: We used data collected in a series of cross-sectional surveys between March 2005 and July 2009. Patients with CKD-NOD were selected from a random sample of free-standing US nephrology clinics. Information on demographics, insurance information, laboratory data and ESA use was abstracted from medical records by site investigators. We evaluated ESA treatment (use and dosing) and Hb levels over time and used multivariate linear regression to assess changes in ESA doses and Hb levels over time adjusting for case-mix differences., Results: Between 2005 and 2009, 15 836 CKD-NOD patients were sampled. During this period, ESA use declined from 60 to 46%, and the mean dose declined from 176 to 136 mcg/month; the largest decline in use and in dose occurred beginning in 2007. Simultaneously, the mean (standard deviation) Hb level in ESA-treated patients declined from 11.5 (1.4) to 10.6 (1.2) g/dL, though the decline was most pronounced starting in 2007. As the mean Hb declined, the percent of treated patients with an Hb > 12 g/dL dropped from 27 to 12%, and the mean dose in this sub-population declined from 173 to 111 mcg/month., Conclusion: The emergence of safety concerns and the subsequent changes in product labeling, reimbursement and clinical practice guidelines all appear to have influenced physician dosing practices resulting in less frequent use of ESAs, lower ESA doses and lower achieved Hb levels in CKD-NOD patients.

Background: Erythropoiesis-stimulating agents (ESAs) are frequently used to treat anaemia of chronic kidney disease (CKD) in the dialysis setting; however, few data are available regarding factors influencing initiation of ESAs and other therapies in non-dialysis patients., Methods: A retrospective cohort study of Veterans Health Administration data from 2003 to 2005 for 89 585 patients identified as having CKD and anaemia based on two outpatient estimated glomerular filtration rates <60 ml/min/1.73 m(2) and at least one outpatient haemoglobin (Hb) <11 g/dL. Hb levels, patient demographics, clinical and provider characteristics and procedures predicted ESA treatment initiation over 1 year of follow-up. Multivariable logistic and pooled logistic survival models identified predictors of ESA initiation., Results: Overall, 6381 subjects (7.1%) initiated ESAs within 1 year of the index Hb; initiation was more common (8.6%) for patients with Hb <10 g/dL. Iron therapy use varied by initial Hb levels (27.6% to 52.4%) as did transfusions (12.5% to 42.8%); each was more common at lower Hb levels. Hbs rose to above 11 g/dL for 25-50% of patients in the absence of any treatment or by transfusion/iron therapy. Factors predicting time to ESA initiation included: nephrologist [odds ratio (OR = 2.3)] or haematologist care (OR = 2.2) and iron therapy (OR = 1.6). Transfusions increased for patients with increasing follow-up time., Conclusion: Iron therapy is more common than ESA treatment in patients with CKD and Hbs <11 g/dL in the VA. Correction of anaemia in the absence of any ESA treatment was common at higher Hbs levels, but much less so when Hb levels fell below 10 g/dL.

Background: Inflammation in an ESRD patient may impact responsiveness to erythropoiesis-stimulating agent (ESA) therapy. We sought to investigate the association between C-reactive protein (CRP) levels and average per-administration epoetin alfa (EPO) dose over 3 months following a CRP measurement., Methods: The study is a retrospective cohort study of hemodialysis patients >or=18 years of age receiving care at a Fresenius Medical Care-North America facility between 1 July 2000 and 30 June 2002 who had no history of peritoneal dialysis. All patients had >or=1 CRP measurement and >or=3 months of recorded information before the CRP measurement (entry period). We evaluated the association between CRP levels and average hemoglobin (Hb) and per-administration EPO dose over the 3 months following the CRP measurement., Results: We identified 1754 patients with a CRP measurement; mean age was 62.6 years (SD 14.1), 51.5% were male, 56.2% were white and the median CRP value was 2.04 mg/dL (20.4 mg/L). Patients in the upper CRP quartiles were more likely to be older, recently hospitalized; have a catheter vascular access; have lower albumin, Hb and transferrin saturation levels and greater EPO doses. In the subsequent 3 months, EPO doses but not Hb levels were significantly higher for patients in the highest CRP quartile [3.21 mg/dL (32.1 mg/L)] (P = 0.01)., Conclusions: Inflammation as measured by an elevated CRP level appears to be an independent predictor of greater ESA dose requirements. Patients with the highest CRP levels required significantly higher ESA doses to achieve comparable Hb levels even after controlling for potential confounding variables.