Supervisors info:
Τριμελής Εξεταστική Επιτροπή
1. Χαλιάσος Αλέξανδρος (Επιβλέπων): Ιατρός - Κλινικός Χημικός – EurClinChem
2. Μαρκαντώνη-Κυρούδη Σοφία: Καθηγήτρια, Τμήμα Φαρμακευτικής, ΕΚΠΑ.
3. Καραλής Βαγγέλης: Καθηγητής, Τμήμα Φαρμακευτικής, ΕΚΠΑ
Summary:
Background: There is a variety of pathological conditions associated with vitamin D deficiency, hence increasing the risk of osteoporotic fractures, cancer, diabetes, and hypertension. Therefore, measuring vitamin D levels, particularly 25-hydroxyvitamin D [25(OH)D] sheds light not only on the vitamin D status in the body, but also allows timely prevention measure for vitamin D-related diseases. Consequently, laboratory detection tests and measurements of both vitamin D and parathyroid hormone (PTH) have been developed to meet all the necessary diagnostic needs. However, available data comparing the methods that have been used are limited. What remains important is the performance of comparative studies on laboratory methods in order to discuss the reliability of these measurements. The aim of this study was to evaluate and critically discuss the differences resulting from the measurements of vitamin D and PTH when using the electrochemiluminescence immunoassay (ECLIA) method (e.g. Roche Diagnostics Cobas e-411 analyzer), the chemiluminescence immunoassay (CLIA) method (e.g. Snibe Diagnostics Maglumi X3 analyzer) and the IDS (CLIA) method (e.g. ISYS analyzer).
Methods: A total of 161 serum and plasma samples from healthy adult individuals were collected. The samples were centrifuged at 4°C and then stored at -80°C until measurement in the laboratory. Each sample underwent simultaneous analysis for both 25(OH)D and PTH, following the protocol determined by each manufacturer.
Results: In the ECLIA method, the mean levels of 25(OH)D ranged from 5.89 to 45.71 pg/mL, whereas in the CLIA method, the mean levels ranged from 13.89 to 64.19 pg/mL. Similarly, in the ECLIA method, the mean levels of PTH ranged from 6.3 to 87.49 pg/mL, whereas in the CLIA method, the mean levels ranged from 11.3 to 142.0 pg/mL. In the IDS method, the mean levels of 25(OH)D ranged from 7.36 to 45.9 pg/mL, whereas the mean levels of PTH ranged from 6.3 to 87.49 pg/ml. The regression analysis between the methods revealed a linear model (p>0.05). The IDS method had a better correlation with the reference (diagnostic thresholds <10%).
Conclusions: Significant differences exist between the three measurement methods. In clinical practice, defining vitamin D and PTH levels using various analytical methods should be further investigated, in order to establish a global reference range for both vitamin D and PTH.
