ABSTRACT
BACKGROUND: The third-generation bio-intact parathyroid hormone (PTH) (1–84) assay was designed to overcome problems associated with the detection of C-terminal fragments by the second-generation intact PTH assay. The two assays have been compared primarily among dialysis populations. The present study evaluated the correlations and differences between these two PTH assays among patients with chronic kidney disease (CKD) stages 3 to 5 not yet on dialysis. METHODS: Blood samples were collected from 98 patients with CKD stages 3 to 5. PTH concentrations were measured simultaneously by using the second-generation - PTH intact-STAT and third-generation bio-intact 1–84 PTH assays. Other serum biomarkers of bone mineral disorders were also assessed. CKD stage was calculated by using the CKD-Epidemiology Collaboration (EPI) formula. RESULTS: Serum bio-intact PTH concentrations were strongly correlated but significantly lower than the intact PTH concentrations (r=0.963, P<0.0001). This finding was consistent among CKD stages 3 to 5. PTH concentrations by both assays (intact and bio-intact PTH) positively correlated with urea (r=0.523, r=0.504; P=0.002, respectively), phosphorus (r=0.532, r=0.521; P<0.0001, respectively) and negatively correlated with blood calcium (r=−0.435, r=−0.476; P<0.0001, respectively), 25(OH) vitamin D, (r=−0.319, r=−0.353; respectively, P<0.0001) and the estimated glomerular filtration rate (r=−0.717, r=−0.688; P<0.0001, respectively). CONCLUSIONS: Among patients with CKD stages 3 to 5 not on dialysis, the bio-intact PTH assay detected significantly lower PTH concentrations compared with intact PTH assay. Additional studies that correlate the diagnosis and management of CKD mineral and bone disorders with bone histomorphometric findings are needed to determine whether bio-intact PTH assay results are better surrogate markers in these early stages of CKD.
Subject(s)
Humans , Biomarkers , Calcium , Cooperative Behavior , Diagnosis , Dialysis , Glomerular Filtration Rate , Hyperparathyroidism, Secondary , Miners , Parathyroid Hormone , Phosphorus , Renal Insufficiency, Chronic , Urea , Vitamin DABSTRACT
ABSTRACT Objective To evaluate the usefulness of a third-generation PTH assay in the diagnosis of primary hyperparathyroidism (PHPT). Subjects and methods Forty-one PHPT patients (4 men and 37 women) with 61.2 ± 10.9 (mean ± SD) years, were studied and had PTH levels measured with two different methods using the same immunochemiluminescent assay plataform (Elecsys 2010 System, Roche). We compared a second-generation assay (I-PTH) with a third-generation PTH assay (Bio-PTH). Two populations of 423 and 120 healthy adults with serum 25OHD levels above 25 ng/mL were used to define normal values in the I-PTH and Bio-PTH assays respectively. Results Normal PTH values based in the healthy adults population were 24.2-78.0 pg/mL for the I-PTH assay and 19.9-58.5 pg/mL for Bio-PTH assay. In PHPT patients, PTH values ranged from 67 to 553 pg/mL (median: 168 pg/mL) using the I-PTH assay and from 55 to 328 pg/mL (median: 111 pg/mL) using the Bio-PTH assay. Results obtained with the Bio-PTH assay were significantly lower (p < 0.0001, Wilcoxon). In general I-PTH and Bio-PTH showed highly significant correlation (r = 0.952, p < 0.0001). Passing–Bablok analysis gave a regression equation of Bio PTH = 13.44 + 0.59 x intact PTH. PHPT patients had 25OHD levels ranging from 4 to 36 ng/mL (mean 16.2 ng/mL); 35 subjects (85.3%) had values bellow 25 ng/mL. Conclusion Our results demonstrate that both second and third generation PTH methods are strongly correlated in PHPT patients and control subjects. Lower results with Bio-PTH tests are expected in function of the assay specificity determined by the amino-terminal antibody used.
Subject(s)
Humans , Male , Female , Middle Aged , Parathyroid Hormone/blood , Peptide Fragments/blood , Hyperparathyroidism, Primary/diagnosis , Hyperparathyroidism, Primary/blood , Reference Standards , Reference Values , Brazil , Immunoassay/methods , Biomarkers/blood , Case-Control Studies , Reproducibility of Results , Statistics, Nonparametric , Luminescent Measurements/methodsABSTRACT
BACKGROUND: Medical treatments such as restriction of phosphate, phosphate binder use, and active vitamine D therapy have been widely used for hyperparathyroidism in ESRD patients, and surgical parathyroidectomy should be considered in patients with uncontrolled hyperparathyroidism. METHODS: A retrospective study was performed in 24 ESRD patients with severe and uncontrolled hyperparathyroidism despite of medical treatment who undertook surgical parathyroidectomy in Severance hospital from 1990 to 1999. RESULTS: Sixteen patients had total parathyroidectomy with immediate autotransplant, 7 patients had subtotal parathyroidectomy and only 1 patient had minimally invasive parathyroidectomy. An excellent short-term control of hyperparathyroidism was achieved in all patients after parathyroidectomy. Preoperative bone and joint pain improved in 16 of 19 patients. Muscle weakness and pain improved in 11 of 17 patiens, malaise improved in 8 of 10 patients and pruritus improved in 10 of 13 patients. In addition, clinical laboratory finding improved after parathyroidectomy. No clinical differences were seen between 16 patients who undertook total parathyroidectomy with immediate autotransplant and 7 patients who undertook subtotal parathyroidectomy. Recurrence of hyperparathyroidism ocurred in 5 of 24 patients with 4 nodular hyperplasia and 1 diffuse hyperplasia in pathologic finding. The less degree of attenuated response of intact PTH levels immediately after operation was observed in 5 recurrent cases. CONCLUSION: Good results were obtained after parathyroidectomy. We believe that histologic subtype and the attenuated response of intact PTH after surgical parathyroidectomy could be possible predictors of the recurrent hyperparathyroidism.