Correlation of Serum Collagen I Carboxyterminal Telopeptide Concentrations with Cutaneous and Pulmonary Involvement in Systemic Sclerosis

YANNICK ALLANORE, DIDIER BORDERIE, HERVE LEMARÉCHAL, BRIGITTE CHERRUAU, OHVANESSE G. EKINDJIAN, and ANDRE KAHAN

ABSTRACT.

Objective. Systemic sclerosis (SSc) is characterized by fibrosis involving the skin and various internal organs. Type I collagen (Col I) is the most abundant extracellular matrix protein deposited in cutaneous involvement. We investigated Col I biochemical markers in patients with SSc.

Methods. All consecutive patients admitted for SSc over a 9 month period and a healthy control group were investigated. Serum concentrations of the C-terminal telopeptide of Col I (s-CTX-I), C-terminal type I procollagen propeptide (PICP), osteocalcin, and bone alkaline phosphatases (ALP), and urinary concentrations of deoxypyridinoline (u-DPD) and u-CTX-I were determined by ELISA.

Results. A total of 33 patients with SSc were included: mean age ± SD was 54 ± 12 yrs, with a mean disease duration of 5.4 ± 3.9 years. Sixteen of 33 patients with SSc had s-CTX-I values exceeding the upper limit of normal values of the test and the mean ± SEM was significantly higher (7388 ± 1422 pmol/l) than in healthy controls (2800 ± 1120 pmol/l; p < 0.001). s-CTX-I correlated with the Rodnan skin score (p = 0.003); it was higher in patients with diffuse disease (8459 ± 3125; n = 14) than in patients with the limited form (6453 ± 1235; n = 19; p < 0.02). This marker also correlated with acute phase reactants (C-reactive protein, p = 0.004; erythrocyte sedimentation rate, p = 0.02). s-CTX-I was high in patients with positive antitopoisomerase I autoantibodies (p = 0.04) and in patients with a decrease in forced vital capacity to less than 75% (p = 0.02). u-DPD concentration was high in patients with SSc (10.6 ± 1.4 nmol/mmol creatinine vs 6.3 ± 2.1 in controls; p < 0.01). No difference between patients and controls or correlations with the disease were found for PICP, u-CTX-I, osteocalcin, and bone ALP concentrations.

Conclusion. s-CTX-I, a marker of Col I degradation, is correlated with cutaneous and pulmonary involvement and with acute phase reactants in patients with SSc. This marker is a good candidate for further evaluation for disease activity and treatment purposes. (J Rheumatol 2003;30:68-73)

Key Indexing Terms:

SYSTEMIC SCLEROSIS
COLLAGEN I
C-TELOPEPTIDE

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From the Department of Rheumatology A and Department of Biochemistry A, Paris V University, Assistance Publique Hôpitaux de Paris, Cochin Hospital, Paris, France.

Y. Allanore, MD; A. Kahan, MD, PhD, Professor of Rheumatology, Department of Rheumatology; D. Borderie, MD, PhD; H. Lemaréchal, Postgraduate Student; B. Cherruau, MD, PhD; O.G. Ekindjian, MD, PhD, Department of Biochemistry.

Address reprint requests to Dr. Y. Allanore, Hôpital Cochin, Service de Rhumatologie A, 27 rue du faubourg Saint-Jacques, 75014 Paris, France. E-mail: yannick.allanore@cch.ap-hop-paris.fr

Submitted December 10, 2001; revision accepted July 8, 2002.

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