A further study in the July issue of Ophthalmology, the journal of the American Academy of Ophthalmology, investigated inflammation biomarkers in relation to corneal transplant rejection in herpes simplex patients. Its results have shown that inflammation thwarts corneal transplants.
The herpes simplex virus (HSV) can infect the eye and sometimes causes so much damage that the person's cornea must be replaced with a transplant. Doctors knew transplants were more likely to fail in people with HSV than in patients with other disorders, such as keratoconus and that this higher failure rate occurred even when HSV infection did not appear to be active in patients. Researchers at the Kellogg Eye Center, University of Michigan, theorized that such patients might have corneal inflammation that could not be detected upon clinical examination but might increase the risk of transplant rejection.
To test this theory, a study led by Victor M. Elner, MD, PhD, examined the corneal tissue, removed during surgery, of 62 Kellogg Eye Center patients (between 1990 and 2000) to identify inflammation biomarkers that might be linked to rejection of transplants. Unlike organ transplants, in corneal procedures the new tissue is placed on a bed of existing tissue. Though HSV had been inactive for six months before surgery in 81% of patients, microscopic evidence of inflammation was found in 74%, and the transplant failure rate did correlate with the presence of this biomarker. Testing for inflammatory biomarkers will help ophthalmologists predict whether an HSV patient is likely to reject a transplant.
"It is also possible that treating inflammation intensively before corneal transplant surgery would reduce the risk of rejection," said Dr Roni M. Shtein, MD, MS, cornea specialist and lead author of the report.