Factor XIII subunits in human tears; their highly elevated levels following penetrating keratoplasty.
BACKGROUND
As blood coagulation factor XIII (FXIII) is of high importance in wound healing, we determined the concentrations of FXIII A and B subunits (FXIII-A and FXIII-B) and their complex (FXIII-A(2)B(2)) in normal tears and in tears from patients undergoing penetrating keratoplasty (PKP).


METHODS
FXIII complex and subunit concentrations were measured by highly sensitive chemiluminescent ELISAs in tears from 60 healthy volunteers and from 31 patients undergoing corneal transplantation.


RESULTS
In non-stimulated tears from healthy volunteers, low but consistent amounts of FXIII-A and FXIII-B (medians: 2.13 μg/L and 7.22 μg/L, respectively) were measured, mostly in non-complexed form. Following stimulation of tear secretion FXIII levels moderately decreased, but if normalized to protein concentration they did not change. One day after PKP FXIII levels became highly elevated, then gradually decreased, but even on day 7 significantly exceeded pre-surgery values. The elevation of tear FXIII levels was significantly higher in PKP patients who later developed neovascularization of donor cornea.


CONCLUSIONS
FXIII subunits are low concentration components of normal tear. The striking elevation of FXIII subunit and FXIII-A(2)B(2) concentrations after PKP suggests the involvement of FXIII in corneal wound healing. Perioperatively measured high FXIII levels in tears seem to represent a risk of neovascularization.
Clinical Research Center, University of Debrecen, Medical and Health Science Center, 98 Nagyerdei krt., 4032 Debrecen, Hungary.
Zsuzsanna Z
ZZ
Orosz
Éva
É
Katona
Andrea
A
Facskó
László
L
Módis
László
L
Muszbek
András
A
Berta
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005176:Factor XIII / Q000378:metabolism*; D005260:Female; D006801:Humans; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D021122:Protein Subunits / Q000378:metabolism; D013666:Tears / Q000378:metabolism*; D055815:Young Adult
D021122:Protein Subunits; D005176:Factor XIII