Detection of Mycobacterium tuberculosis in corneas from donors with active tuberculosis disease through polymerase chain reaction and culture.

OBJECTIVE

To determine if Mycobacterium tuberculosis can be detected in corneas of donors who have active tuberculosis (TB) disease using polymerase chain reaction (PCR) or culture.

DESIGN

This is a prospective cross-sectional study.

PARTICIPANTS

25 corneas (12 from TB-negative donors and 13 from TB-positive donors) from the Sta. Lucia International Eye Bank were submitted to the TB Research Laboratory, Medical Research Laboratory, Department of Medicine, UP-PGH, for diagnostic evaluation.

INTERVENTION: Corneas were evaluated using PCR test for M tuberculosis. Acid-fast bacilli smear and culture were also done.

MAIN OUTCOME MEASURES: Result of laboratory findings.

RESULTS

Among 12 TB-negative donors, there were 2 (16.67%) corneas that were PCR negative for M tuberculosis, whereas 10 (83.33%) corneas were PCR positive for M tuberculosis. Among 13 TB-positive donors, there were 7 (53.85%) corneas that were PCR negative for M tuberculosis, whereas 6 (46.15%) corneas were PCR positive for M tuberculosis. All cultures were negative.

CONCLUSION

PCR for M tuberculosis was positive for some TB-positive donors as well as TB-negative donors. However, all cultures were negative. It is recommended that further studies be done to investigate if recipients with PCR-positive corneas will eventually lead to disease transmission or not. It is further recommended that such findings be used to re-evaluate criteria for suitability of donors with tuberculosis.