Original Paper

Effects of Calcitriol on Type 5b Tartrate-Resistant Acid Phosphatase and Interleukin-6 in Secondary Hyperparathyroidism
Kuo-Cheng Lu^{a, b}, Chin-Feng Tseng^a, Chia-Chao Wu^b, Lai-King Yeung^a, Jin-Shuen Chen^b, Tsu-Yi Chao^c, Anthony J. Janckila^{d, f}, Lung T. Yam^d-f, Pauling Chu<sup>b

a</sup>Division of Nephrology, Department of Medicine, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University and Divisions of
^bNephrology and
^cHematology and Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Departments of
^dMicrobiology and Immunology and
^eMedicine, University of Louisville and
^fSpecial Hematology Laboratory, US Department of Veterans Affairs Medical Center, Louisville, Ky., USA

Address of Corresponding Author

Blood Purif 2006;24:423-430 (DOI: 10.1159/000094899)

  Key Words

• Calcitriol
• Alkaline phosphatase, bone-specific
• Hyperparathyroidism, secondary
• Tartrate-resistant acid phosphatase
• Interleukin-6

  Abstract

Background/Aims: Secondary hyperparathyroidism (SHP) is characterized by high bone turnover and elevated serum bone remodeling markers. Elevation of serum interleukin-6 (IL-6) levels is also characteristic of end-stage renal disease. This study investigates the effects of intravenous calcitriol on serum bone resorptive markers, namely, type 5b tartrate-resistant acid phosphatase (TRACP5b) and IL-6 in patients with SHP. Methods: Intravenous calcitriol therapy was given for 16 weeks to 24 patients on maintenance hemodialysis with plasma intact parathyroid hormone (iPTH) levels >300 pg/ml. Blood was drawn at baseline and every 4 weeks for 16 weeks for determination of the levels of biochemical parameters, iPTH, IL-6 and bone remodeling markers, including bone-specific alkaline phosphatase (bAP) and TRACP5b. Results: Only 21 patients responded to the calcitriol therapy, with significant decrements in serum iPTH after 4 weeks of therapy and thereafter. After 16 weeks of calcitriol therapy, 21 patients had significant decrements in serum iPTH (707.9 ± 317.8 vs. 205.0 ± 63.1 pg/ml, p < 0.01). Prior to treatment, a significant correlation was found between increased levels of serum iPTH and IL-6 levels (r = 0.45, p < 0.05). After treatment, there was also a significant and parallel lowering of levels of serum iPTH, IL-6 (8.52 ± 3.59 vs. 7.24 ± 2.81 pg/ml, p < 0.01), bAP (54.68 ± 36.17 vs. 24.55 ± 13.84 U/l, p < 0.01) and TRACP5b (3.41 ± 1.89 vs. 1.80 ± 0.55 U/l, p < 0.01). Our results additionally showed significant positive correlationsbetween baseline levels of serum IL-6 and those of iPTH, bAP and TRACP5b. After 16 weeks of calcitriol treatment, the correlation between IL-6 and iPTH levels lost significance but levels of serum IL-6, bAP and TRACP5b remained significantly correlated. Conclusions: Elevated levels of serum IL-6 and bone remodeling markers, namely, bAP and TRACP5b which are common features of SHP, are effectively suppressed by calcitriol therapy. This indicates that hyperparathyroidism not only accelerates bone remodeling but may also aggravate inflammation in patients on maintenance hemodialysis.

Copyright © 2006 S. Karger AG, Basel

  Author Contacts

Prof. Pauling Chu, MD, PhD
Division of Nephrology, Department of Internal Medicine
Tri-Service General Hospital, National Defense Medical Center
325 Section 2, Cheng-Kung Road, Neihu 114, Taipei (Taiwan)
Tel. +886 2 8792 7213, Fax +886 2 8792 7134, E-Mail pchu@seed.net.tw

  Article Information

Received: February 15, 2006
Accepted: May 31, 2006
Published online: August 4, 2006
Number of Print Pages : 8
Number of Figures : 2, Number of Tables : 2, Number of References : 29