Assessment of tissue fibrosis in skin biopsies from patients with systemic sclerosis employing confocal laser scanning microscopy: an objective outcome measure for clinical trials?
OBJECTIVE
To obtain an objective, unbiased assessment of skin fibrosis in patients with SSc for use in clinical trials of SSc disease-modifying therapeutics.


METHODS
Skin biopsies from the dorsal forearm of six patients with diffuse SSc and six healthy controls, and skin biopsies from the forearm of one patient with diffuse SSc before and following 1 year treatment with mycophenolate mofetil were analysed by confocal laser scanning microscopy (CLSM) with specific antibodies against collagen types I and III or fibronectin. The integrated density of fluorescence (IDF) was calculated employing National Institutes of Health-ImageJ software in at least four different fields per biopsy spanning the full dermal thickness.


RESULTS
The intensities of collagen types I and III and fibronectin IDF were 174, 147 and 139% higher in SSc skin than in normal skin, respectively. All differences were statistically significant. The sum of the IDF values obtained for the three proteins yielded a comprehensive fibrosis score. The average fibrosis score for the six SSc samples was 28.3 x 10(6) compared with 18.6 x 10(6) for the six normal skin samples (P < 0.0001). Comparison of skin biopsies obtained from the same SSc patient before treatment and after 12 months of treatment with mycophenolate mofetil showed a reduction of 39% in total fibrosis score after treatment.


CONCLUSIONS
CLSM followed by quantitative image analysis provides an objective and unbiased assessment of skin fibrosis in SSc and could be a useful end-point for clinical trials with disease-modifying agents to monitor the response or progression of the disease.
Busquets
Joanna
J
Jefferson Institute of Molecular Medicine, Thomas Jefferson University, 233 S. 10th Street, Philadelphia, PA 19107-5541, USA.
Del Galdo
Francesco
F
Kissin
Eugene Y
EY
Jimenez
Sergio A
SA
D000328:Adult; D001706:Biopsy; D016022:Case-Control Studies; D002986:Clinical Trials as Topic; D003094:Collagen / Q000378:metabolism; D005260:Female; D005355:Fibrosis / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D012595:Scleroderma, Systemic / Q000188:drug therapy / Q000473:pathology*; D012867:Skin / Q000033:anatomy & histology / Q000378:metabolism; D013223:Statistics as Topic
D007166:Immunosuppressive Agents; D003094:Collagen; D009173:Mycophenolic Acid