Longitudinal analysis of serum KL-6 levels in patients with systemic sclerosis: association with the activity of pulmonary fibrosis.
OBJECTIVE
To determine whether changes in serum KL-6 levels reflect the activity of pulmonary fibrosis (PF) in patients with systemic sclerosis (SSc).


METHODS
KL-6 levels were determined by ELISA in 39 SSc patients. In a retrospective longitudinal study, 250 serum samples were analyzed during a follow-up period of 0.3-6.1 years.


RESULTS
KL-6 levels at the first visit were higher in patients with SSc, especially with PF, compared with healthy controls. In the longitudinal study, KL-6 levels in 4 patients with anti-topo I Abs increased rapidly, parallel to the progression of PF. Four patients with inactive PF exhibited elevated, but stable levels of KL-6 during the follow-up. The 31 patients with almost normal KL-6 levels during the follow-up exhibited no deterioration or new onset of PF.


CONCLUSIONS
Rapidly increased serum KL-6 levels during disease course were associated with new onset or deterioration of PF.
Yanaba
K
K
Department of Dermatology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
Hasegawa
M
M
Hamaguchi
Y
Y
Fujimoto
M
M
Takehara
K
K
Sato
S
S
D000328:Adult; D000704:Analysis of Variance; D000941:Antigens / Q000097:blood*; D000951:Antigens, Neoplasm; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins; D011336:Probability; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000097:blood* / Q000150:complications* / Q000175:diagnosis; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000097:blood* / Q000150:complications* / Q000175:diagnosis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed
D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers; D006023:Glycoproteins; C060192:MUC1 protein, human; D018396:Mucin-1; D009077:Mucins