Further investigations on the association of Mycobacterium tuberculosis with Eales' disease.

ABSTRACT

PURPOSE: To apply polymerase chain reaction (PCR) on vitreous fluid (VF) from Eales' disease to further confirm its association with Mycobacterium tuberculosis. METHODS: Sixty nine VF samples from 69 patients (24 Eales' disease and 45 Non-Eales' as controls) were processed by conventional methods for detection of mycobacteria. Polymerase chain reaction (PCR) specific for IS 6110 and nested PCR (nPCR) using primers coding for MPB 64 gene were applied on all 69 VF. PCR based dot-blot hybridisation was applied on the IS 6110 amplified products of n PCR-positive VFs. RESULTS: Conventional methods (direct smear and culture) did not detect mycobacteria in any of the 69 VF samples. Five (20.8%) of 24 VF from Eales' and 2 (4.2%) of 45 VF from control patients tested positive for M. tuberculosis DNA by nPCR. This difference was statistically significant (P < 0.05). All 69 VF were negative by PCR for IS 6110. Two VF of Eales' patients positive by nPCR were also positive by DNA probe dot-blot hybridisation for IS 6110. CONCLUSION: Detection of M. tuberculosis DNA by PCR in a significant number of VF of Eales' disease patients reemphasizes the association of this bacterium with Eales' disease.