Inflammatory molecules in the tears of patients with keratoconus.
OBJECTIVE
To determine levels of a panel of inflammatory molecules and matrix metalloproteinases in the tears of patients with keratoconus.


METHODS
A prospective, case-control study.


METHODS
Twenty-eight patients (1 eye from each) diagnosed with keratoconus at the Instituto Galego de Oftalmoloxia, Santiago de Compostela, Spain, during the period from September 2001 to June 2002, and 20 normal control subjects (1 eye each) were studied.


METHODS
Patients with keratoconus were examined in a routine fashion, and keratometric readings were taken to monitor the degree of ectasia. Fifteen microliters of tears was collected by capillary flow from each eye.


METHODS
The concentrations of cytokines (interleukin-4 [IL-4], IL-6, IL-10, and tumor necrosis factor alpha [TNF-alpha]), cell adhesion molecules (intercellular adhesion molecule 1 and vascular cell adhesion molecule 1), and matrix metalloproteinase 9 (MMP-9) were measured by enzyme-linked immunoadsorbent assay.


RESULTS
Patients with keratoconus initially had significantly higher levels of IL-6 (6.7 [4.8-10.8] pg/ml vs. 2.2 [1.0-4.1] pg/ml in control subjects [P<0.0001]), TNF-alpha (3.8 [2.9-14.4] pg/ml vs. 1.8 [1.5-2.3] pg/ml in control subjects [P<0.0001]), and MMP-9 (66.5 [49.2-139.3]ng/ml vs. 6.1 [3.9-8.3] ng/ml in control subjects. The extent of the increase was found to be associated with the severity of keratoconus.


CONCLUSIONS
Interleukin-6, TNF-alpha, and MMP-9 are overexpressed in the tears of patients with keratoconus, indicating that the pathogenesis of keratoconus may involve chronic inflammatory events.
Lema
Isabel
I
Instituto Galego de Oftalmoloxía, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
Durán
Juan A
JA
D000328:Adult; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D007640:Keratoconus / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D011446:Prospective Studies; D013666:Tears / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D018836:Inflammation Mediators; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D020780:Matrix Metalloproteinase 9