Quantitative Polymerase Chain Reaction forMycobacterium tuberculosisin So-called Eales’ Disease

Abstract

MTB genome was demonstrated in more than 50% of vitreous fluid samples with significant bacillary load, indicating that half of patients with so-called Eales' disease are indeed cases of tubercular vasculitis.

Controversies in ocular tuberculosis

“…Furthermore, these tests are affected by the volume of the sample, method of DNA extraction, number of targets used for amplification and presence of inhibitors in the sample 18. The specificities of these tests are high but sensitivities have been variable, that is, PCR: 33%–67%,21 quantitative real-time PCR: 57%,22 multiplex PCR: 78% and loop-mediated isothermal amplification test: 86% 23. Moreover, all these tests usually require specialised and/or expensive laboratory equipment or reagents.…”

Infectious Uveitis

“…However, recent demonstration of MTB DNA in ocular samples from Eales’ disease patients argues for the treatment of this disease as a primarily infectious rather than inflammatory disease. [ 52,53 ]…”

devR PCR for the Diagnosis of Intraocular Tuberculosis

“…The sensitivity of IS6110 PCR is reported between 37 and 58.82%. 10,11,23 MPB64 has been reported as 10,000 times more sensitive than IS6110 for the diagnosis of tubercualr uveitis. 14 Our study supports this finding.…”

“…21 The MPB64 PCR were performed using the forward primer MPB641 (5 0 -TCCGCTGCCAGTCGTCTTCC-3 0 ) and reverse primer MPB642 (5 0 -GTCCTCGCGAGTCTAGGCCA-3 0 ), which amplified a 240-base pair fragment of the MPB64 single copy gene. 23 During DNA extraction and amplification, strict precautions were taken, including separate areas for DNA extraction, reagent preparation, amplification, and product detection, and regular meticulous cleaning of surfaces with 10% hypochlorite. In addition, all the reagents were aliquoted upon arrival in the laboratory.…”