Cross-sectional evaluation of YKL-40 serum concentrations in patients with systemic sclerosis. Relationship with clinical and serological aspects of disease.
OBJECTIVE
To investigate the behavior of serum YKL-40 in a cohort of patients with systemic sclerosis (SSc).


METHODS
Forty SSc patients (35 women, 5 men) were investigated for serum YKL-40, soluble interleukin 2 receptor alpha (sIL-2Ra; by ELISA), von Willebrand factor (vWF; ELISA), and aminoterminal propeptide of type III procollagen (PIIINP; radioimmunoassay) concentrations. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were evaluated. Skin and organ system involvement were scored according to the Medsger organ/system severity scale.


RESULTS
Serum YKL-40 in SSc patients (mean 132.9 ng/ml; median 75.5, 95% CI 87.8-175) was significantly higher than in controls (mean 66.6 ng/ml; median 52, 95% CI 54.6-78.6). Fourteen patients had levels > 135 ng/ml (cutoff value) with a mean of 264.7 +/- 160 ng/ml. Serum YKL-40 values were found to be more frequently increased in patients with arthralgias/arthritis (18 cases) than in patients without such features (4/22) (p = 0.021). Significant differences were found comparing serum YKL-40 concentrations in the patients with or without joint involvement (median 138 vs 57.5 ng/ml, respectively; p = 0.007). Serum YKL-40 levels correlated with the joint involvement severity score (p = 0.018) and sIL-2Ra levels (p < 0.001). No differences were found with any therapeutic regimen.


CONCLUSIONS
This preliminary study shows that YKL-40 serum levels are increased in SSc and that they are correlated with sIL-2Ra and joint involvement, suggesting a relationship with cartilage and/or fibroblast activity.
La Montagna
Giovanni
G
Dipartimento Medico-Chirurgico di Internistica Clinica e Sperimentale F. Magrassi e A. Lanzara, Unità Operativa di Reumatologia, Seconda Università di Napoli, Policlinico Via S. Pansini 5, 80131 Naples, Italy. giovanni.lamontagna@unina2.it
D'Angelo
Salvatore
S
Valentini
Gabriele
G
D054392:Adipokines; D000293:Adolescent; D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D001168:Arthritis / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D000071451:Chitinase-3-Like Protein 1; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007596:Joints / Q000473:pathology / Q000503:physiopathology; D037102:Lectins; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood; D015375:Receptors, Interleukin-2 / Q000097:blood; D012595:Scleroderma, Systemic / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D012720:Severity of Illness Index; D014841:von Willebrand Factor / Q000032:analysis
D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins; D010446:Peptide Fragments; D011347:Procollagen; D015375:Receptors, Interleukin-2; C041876:procollagen Type III-N-terminal peptide; D014841:von Willebrand Factor