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CompletedNCT03464149Updated Jun 25, 2020

The Longitudinal PTH-Study

An observational study in CKD-MBD - Chronic Kidney Disease Mineral and Bone Disorder, Secondary Hyperparathyroidism and Kidney Replacement, sponsored by Medical University of Vienna. Completed at 1 site in Austria. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2020-06-25.

Sponsored by Medical University of Vienna · Observational

Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
132
Ages
18 Years and older
Sex
All
01

Study summary

The main study aim is to quantify the agreement between the analytical results provided by two third generation and two second generation Parathyroid hormone (PTH) assays. The primary comparison will be performed between the second-generation PTH assay"Intact PTH assay" from Siemens Healthcare Diagnostics Inc. and the third-generation PTH assay "biointact (1-84)" from Roche Diagnostics in terms of a Bland-Altman analysis. Several studies have evaluated the correlation between various PTH assays at a single time-point, but no previous study has tested the hypothesis that longitudinal changes in PTH levels, which are important for making treatment decisions, can be monitored by several PTH assays alike. To this aim, the key secondary objective is to analyze the longitudinal variance in PTH over the course of 1 year, using each of two assays of the second and third generations, respectively. Other secondary objectives include determining changes in serum phosphate, serum calcium, fibroblast growth factor 23 (FGF23), with respect to treatment decisions. For clinical applicability of the results to be obtained here, an important goal of the present study will be not to influence treatment decisions, which will remain independent of the study investigators, at the full responsibility of the hemodialysis physicians.

At every quarterly blood draw over the course of one year, the investigators will freeze the serum from 100 patients, and at the end of 4 quarters the investigators will analyze PTH-levels using the following assays: Intact Parathyroid Hormone (Advia Centaur, Siemens Healthcare), PTH-Intact (Cobas, Roche), PTH (1-84) - The agreement between the PTH assays will be analyzed at baseline, as well as at the subsequent quarterly evaluation time-points by Bland-Altman analysis and complemented by Passing-Bablok regression. The longitudinal changes in PTH will be displayed graphically and analyzed by estimating the within-patient variance across time, the between patient variance at each time-point as well as effects on the mean log-PTH level due to course of disease and therapeutic interventions from a linear mixed model.

02

Conditions studied

  • CKD-MBD - Chronic Kidney Disease Mineral and Bone Disorder
  • Secondary Hyperparathyroidism
  • Kidney Replacement
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

132 hemodialysis patients at a single center

Inclusion criteria

  • All patients who were undergoing uninterrupted hemodialysis or hemodiafiltration at the Chronic Hemodialysis Unit of the Division of Nephrology and Dialysis, Medical University of Vienna between November 1st, 2017 and December 31st, 2018.
  • Existence of residual blood samples from four successive quarterly routine controls
  • Age ≥ 18 years
  • The test result of the assay must not have any diagnostic value or therapeutic consequence for the patients included in this study.

Exclusion criteria

Exclusion Criteria:

  • Death during the observational period (all patients must have lived through the 1-year period and must have all 4 quarterly blood draws performed on them).
  • Age \<18 years
04

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
132 participants (actual)
Patient registry
No
Biospecimen retention
Samples without dna

Groups and cohorts

  • Study Arm

    One armed study, blood from each patient is analysed by the following assays: Intact PTH Assay (Siemens Healthcare Diagnostics Inc); LIAISON 1-84 PTH Assay (Diasorin); PTH (1-84), biointact (Roche Diagnostics); PTH, intact (Roche Diagnostics)

    Diagnostic Test: One armed study, blood from each patient is analysed by four assays ( two 3rd generation and two 2nd generation assays)

Interventions

  • Diagnostic testOne armed study, blood from each patient is analysed by four assays ( two 3rd generation and two 2nd generation assays)

    Intact PTH Assay (Siemens Healthcare Diagnostics Inc); LIAISON 1-84 PTH Assay (Diasorin); PTH (1-84), biointact (Roche Diagnostics); PTH, intact (Roche Diagnostics)

05

What researchers measure

Primary outcomes

  1. Longitudinal change in PTH levels measured in [pg/ml]

    PTH levels as measured by the second and third generation assays

    Time frame: Timepoints of four consecutive quarterly routine controls per patient (month 1; month 4 ; month 8, month 12)

Secondary outcomes

  1. Longitudinal within-patient change of PTH levels in [pg/ml]

    Longitudinal within-patient variance of PTH over the course of 1 year, using each of two assays of the second and third generations, respectively.

    Time frame: Timepoints of four consecutive quarterly routine controls per patient (month 1; month 4 ; month 8, month 12)

  2. Serum Calcium levels

    Serum Calcium levels

    Time frame: Timepoints of four consecutive quarterly routine controls per patient (month 1; month 4 ; month 8, month 12)

  3. Serum Phosphate levels

    Serum Phosphate levels as measured by quarterly routine controls

    Time frame: Timepoints of four consecutive quarterly routine controls per patient (month 1; month 4 ; month 8, month 12)

  4. Fibroblast growth factor 23 (FGF23

    Fibroblast growth factor 23 (FGF23) as measured in quarterly routine controls

    Time frame: Timepoints of four consecutive quarterly routine controls per patient (month 1; month 4 ; month 8, month 12)

06

Study locations

1 site
  • Department of Internal Medicine III, Division of Nephrology and Dialysis, Medical University of Vienna, Austria
    Vienna, 1090, Austria
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT03464149
Lead sponsor
Medical University of Vienna
Responsible party
Assoc. Prof. Dr. Manfred Hecking, MD PhD (Ass.Professor Dr., Medical University of Vienna) — Principal investigator
First posted
Mar 13, 2018
Start date
Mar 20, 2018
Primary completion
Dec 5, 2018
Completion
Aug 7, 2019
Last update
Jun 25, 2020

Study contacts

Manfred Hecking, M.D.
principal investigator · Medical University of Vienna, Department of Nephrology and Dialysis

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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