Diagnosis of tubercular uveitis by quantitative po

Authors: Pooja Sharma Reema Bansal Vishali Gupta Amod Gupta

Publish Date: 2010/11/11

Volume: 1, Issue: 1, Pages: 23-27

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Abstract

A qPCR assay using primers targeting the MPB64 gene of Mycobacterium tuberculosis MTB was developed A standard curve for quantification of mycobacterial load was generated Vitreous fluid samples from patients presumed to have tubercular uveitis were assayed to identify and quantify the mycobacterial load The amount of the test sample product was interpolated from the standard curve of cycle threshold values generated from known starting copy number of standard MTB DNAPolymerase chain reaction PCR is a molecular technique for evaluation of very small amounts of DNA and RNA by enzymatic amplification of nucleic acid sequences 1 Several studies have linked specific pathogens to ocular inflammatory syndromes using PCR 1 It has had a major impact on our ability to detect infectious agents causing uveitis including viral uveitis mycobacterial intraocular infections infectious endophthalmitis and protozoa eye diseases 2 The first use of PCR in detecting Mycobacterium tuberculosis MTB from the eye was reported from aqueous samples of two patients with active retinal vasculitis 3Quantitative qPCR or realtime PCR is a variant of PCR using fluorescent probes 4 or SYBR Green dye 5 which better allows the quantification of nucleic acid in the sample It facilitates the monitoring of the progress of a PCR reaction in real time One can start with minimal amounts of nucleic acid and quantify the end product accurately There is no need for the postPCR processing which saves the resources and the timeqPCR has been applied to infectious posterior uveitis caused by viral infections and Toxoplasma gondii 6 In a clinicopathological study it revealed the presence and quantified the number of copies of MTB in the retinal pigment epithelium RPE of an eye with granulomatous panuveitis 5

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