[CIP and CAP fragments of parathormone and selected parameters of calcium-phosphate balance in patients with chronic kidney disease treated with repeated haemodialysis].
BACKGROUND
Chronic kidney disease (CKD) leads to bone and mineral complications, which are manifested, among others, by hyperparathyroidism, calcium-phosphate and vitamin D balance disturbances. The results of investigation assessing the usefulness of CAP/CIP ratio, (cyclase activating PTH/cyclase inactive PTH) as a marker of bone turnover and bone disturbances in this group of patients are contradictory.


OBJECTIVE
was to estimate the concentration of CAP and CIP of parathormone, connection with selected calcium-phosphate balance parameters and usefulness of CAP/CIP ratio to differentiate bone mineral density in patients with CKD treated with repeated haemodialysis.


METHODS
The study included 31 children aged 5 to 18 years. Group I - 15 haemodialysed children. Group II - 16 healthy children. The patients underwent the following serum measurements: calcium concentration (Ca), inorganic phosphate (P), 1.25-dihydroxyvitamin D, parathormone (intact PTH), and CAP, CIP were evaluated with Scantibodies Laboratory Inc test. In group I the densitometric examination was done using the Lunar DPX-L system, performing the overall bone measurement.


RESULTS
In children from group I the average values of iPTH concentration and both CIP and CAP components were significantly elevated (p<0.05) as compared to group II. CAP/CIP ratio in group I was <1; in healthy children >1. Average concentrations of Ca and 1.25(OH)2D in serum of group I were lowered, although without statistical significance in comparison with group II. CAP/CIP ratio does not differentiate the children with bone disturbances. Densitometric examination revealed osteopenic changes in 3 children and osteoporosis in 2 children. There were no statistically significant correlations between the examined parameters.


CONCLUSIONS
1. The CIP/CAP ratio does not differentiate the bone mineral density status and it is not associated with biochemical parameters of calcium-phosphate metabolism. 2. This indicates its poor diagnostic utility with reference to mineralization disturbances in children with chronic kidney disease.
Katedra i Klinika Nefrologii Pediatrycznej Akademii Medycznej we Wroclawiu. dpjonkisz@nefped.am.wroc.pl
Dorota
D
Polak-Jonkisz
Danuta
D
Zwolińska
Wiesława
W
Nahaczewska
D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002648:Child; D003937:Diagnosis, Differential; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism*; D010446:Peptide Fragments / Q000097:blood; D010710:Phosphates / Q000378:metabolism*; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000378:metabolism* / Q000628:therapy*; D014807:Vitamin D / Q000378:metabolism
D015415:Biomarkers; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D010710:Phosphates; D014807:Vitamin D; D002118:Calcium