Trypsin inhibitory capacity in vernal keratoconjunctivitis.
OBJECTIVE
To study tear trypsin inhibitory capacity (T-TIC), serum trypsin inhibitory capacity (S-TIC) and their relationship to matrix metalloproteinases (MMP)-1 and -9 in patients with vernal keratoconjunctivitis (VKC).


METHODS
In the first phase of the study, inactivation of alpha-1 antitrypsin (AAT) by MMP-1 and -9 was investigated in vitro. Subsequently, tear samples were collected after clinical evaluation from 14 patients with active VKC and 15 normal control subjects. Tear cytology was performed on all samples. Levels of T-TIC and S-TIC were determined by spectrophotometry, whereas levels of tear pro-MMP-1, pro-MMP-9, and active MMP-1 and -9 were determined by enzyme-linked immunosorbent assay (ELISA).


RESULTS
MMP-1 and -9 inactivated AAT in vitro. S-TIC was significantly higher (P < 0.0001), and T-TIC (P < 0.0001) significantly lower in VKC samples. Tear levels of pro-MMP-1 and pro-MMP-9, and the activity of MMP-1 and -9 was significantly greater in patients with VKC than in healthy subjects (P < 0.0001). There was no significant correlation between T-TIC, MMP-1, and MMP-9 activity. In addition, T-TIC was not correlated to the total clinical score or to single clinical sign scores.


CONCLUSIONS
In this study, tear trypsin inhibitory capacity was shown to be reduced and tear MMP-1 and -9 activity increased in patients with VKC. Although T-TIC did not correlate with VKC severity, a local reduced inhibitory capacity of ATT may facilitate or prolong conjunctival inflammation in VKC.
Ghavami
Saeid
S
Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
Hashemi
Mohammad
M
de Serres
Fredrick J
FJ
Bajestani
Saeed Naghibzadeh
SN
Mehrabifar
Hamid
H
Leonardi
Andrea
A
D000293:Adolescent; D000328:Adult; D002648:Child; D003233:Conjunctivitis, Allergic / Q000201:enzymology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000378:metabolism*; D013666:Tears / Q000166:cytology / Q000201:enzymology*; D014357:Trypsin / Q000097:blood; D000515:alpha 1-Antitrypsin / Q000378:metabolism*
D015842:Serine Proteinase Inhibitors; D000515:alpha 1-Antitrypsin; D014357:Trypsin; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1