Association of Psoriasin (S100A7) with Clinical Manifestations of Systemic Sclerosis: Is Its Presence in Whole Saliva a Potential Predictor of Pulmonary Involvement?

CHIARA BALDINI, LAURA GIUSTI, LAURA BAZZICHI, FEDERICA CIREGIA, GINO GIANNACCINI, CAMILLO GIACOMELLI, MARICA DOVERI, MARIO DEL ROSSO, STEFANO BOMBARDIERI, and ANTONIO LUCACCHINI

ABSTRACT.

Objective. To evaluate psoriasin (S100A7) expression in whole saliva (WS) of patients with diffuse systemic sclerosis (dSSc) and limited SSc (lSSc), and to correlate its presence with the different clinical manifestations of the disease.

Methods. Forty-four patients with limited or diffuse SSc were enrolled for study. WS proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and psoriasin was identified by Western blot analysis using a specific polyclonal antibody. Patients with other rheumatic diseases with and without lung involvement were enrolled as pathological controls. Statistical analysis was performed to correlate each clinical manifestation with the presence of psoriasin.

Results. Three bands of 12, 24, and 50 kDa corresponding to monomeric and dimeric/multimeric forms of psoriasin were evidenced by immunoblot analysis in WS of 31 out of 44 patients with SSc (70.4%). In the other 13 WS samples, the 12 kDa band was totally absent, while the dimeric and multimeric bands were expressed at optical intensity (OD) levels comparable to the other samples. From a clinical point of view, the presence of 12 kDa monomeric psoriasin was significantly associated with SSc pulmonary involvement and with anti-Scl-70 antibody positivity. No control showed the psoriasin 12 kDa band.

Conclusion. Our results identified salivary 12 kDa psoriasin as a potential predictor of pulmonary involvement in SSc. Thus, a psoriasin assay might be considered as a rapid, noninvasive, useful salivary biomarker for the detection of pulmonary involvement in SSc. (First Release July 15 2008; J Rheumatol 2008;35:1820–4)

Key Indexing Terms:

SALIVA
SYSTEMIC SCLEROSIS
PSORIASIN
S100A7
PULMONARY INVOLVEMENT

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From the Department of Internal Medicine, Division of Rheumatology; Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa; and the Department of Experimental Pathology and Oncology, University of Florence, Florence, Italy.

Supported by grants from the Ministero dell'Istruzione, dell'Università e della Ricerca.

C. Baldini, MD; L. Giusti, PhD; L. Bazzichi, MD; F. Ciregia, Dr; G. Giannaccini, PhD, Associate Professor; M. Doveri, MD; C. Giacomelli, Dr; M. Del Rosso, MD, Professor; S. Bombardieri, MD, Professor; A. Lucacchini, PhD, Professor.

Drs. Baldini and Giusti contributed equally to this work.

Address reprint requests to Dr. A. Lucacchini, Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy. E-mail: lucas@ farm.unipi.it

Accepted for publication April 15, 2008.

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