Detection of Mycobacterium tuberculosis genome in vitreous fluid of eyes with multifocal serpiginoid choroiditis

Abstract

Purpose: To compare 3 different molecular techniques to detect the Mycobacterium tuberculosis genome in vitreous fluid of eyes with multifocal serpiginoid choroiditis (MSC).

Design: Prospective, interventional case series.

Participants: Eleven patients (11 eyes) with active MSC in at least 1 eye underwent diagnostic pars plana vitrectomy (PPV) between October 2012 and December 2013.

Methods: Vitreous fluid samples were subjected to multitargeted polymerase chain reaction (PCR) for a M. tuberculosis assay, the Gene Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA), and a line probe assay (GenoType MTBDRplus; Hain Lifescience, GmbH, Nehren, Germany). The samples with positive results were subjected to rpoB gene sequencing to demonstrate rifampicin resistance. The clinical details, digital fundus imaging, and treatment details and outcomes also were noted.

Main outcome measures: Detection of the M. tuberculosis genome and rifampicin resistance in the vitreous samples.

Results: Of the 11 eyes subjected to PPV, the multitargeted PCR results for tuberculosis were positive for 10 eyes, the MTBDRplus assay results were positive in 6 eyes, and the Gene Xpert MTB/RIF assay results were positive in 4 eyes. Rifampicin resistance was detected in 3 eyes by rpoB gene sequencing, in 3 eyes by the MTBDRplus assay, and in 1 eye by the Gene Xpert MTB/RIF assay.

Conclusions: We detected the M. tuberculosis genome in the vitreous fluid of eyes with MSC using 3 different molecular techniques. Rifampicin resistance was detected for the first time in eyes with MSC.