Kusum Sharma

Classification of Intraocular Tuberculosis

Abstract Tuberculosis in the TB endemic countries commonly manifests in the eye as tuberculous uveitis. There is a wide spectrum of the clinical manifestations of intraocular tuberculosis (IOTB). For want of any gold standard diagnostic tests or diagnostic criteria, the estimates of IOTB prevalence have varied greatly. None of the previously suggested guidelines for diagnosis of IOTB have been validated. We give definitions of clinical signs and diagnostic tests that have been used in the literature. Based on these, we propose a classification of IOTB comprising “confirmed IOTB,” “probable IOTB,” and “possible IOTB.” This of necessity needs consensus among experts before carrying out studies to validate this classification.

Novel multi-targeted polymerase chain reaction for diagnosis of presumed tubercular uveitis.

BackgroundThe objective of this study was to report the use of multi-targeted polymerase chain reaction (PCR) in the diagnosis of presumed tubercular uveitis. Multi-targeted PCR using three targets specific for Mycobacterium tuberculosis, i.e., IS6110, MPB64, and protein b, was performed on intraocular fluid samples of 25 subjects. Nine had presumed tubercular uveitis, six had intraocular inflammation secondary to a nontubercular etiology (disease controls), and ten had no evidence of intraocular inflammation (normal controls). As described previously, response to antitubercular therapy was considered as the gold standard.ResultsMulti-targeted PCR was positive in seven out of nine patients with presumed tubercular uveitis and negative in all normal and disease controls. The sensitivity and specificity were 77.77% and 100%, respectively. For the diagnosis of presumed tubercular uveitis, multi-targeted PCR had a positive predictive value of 100% and a negative predictive value of 88.88%.ConclusionMulti-targeted PCR can be a valuable tool for diagnosing presumed tubercular uveitis.

Relapsing polychondritis: a review.

Relapsing polychondritis is a rare multisystem disease involving the cartilaginous and proteoglycan rich structures. The spectrum of clinical presentations may vary from intermittent episodes of painful and often disfiguring auricular and nasal chondritis, to occasional organ or even life-threatening manifestations like airway collapse. There is lack of awareness about this disease due to its rarity. Relapsing polychondritis disease activity index has recently been validated and may help in clinical decision making and research. This article reviews the literature on this disease entity.

Quantitative polymerase chain reaction for Mycobacterium tuberculosis in so-called Eales' disease.

Purpose: To report mycobacterial load in the vitreous of patients labeled as having Eales’ disease. Methods: Eighty-eight patients were prospectively enrolled into 3 groups: 28 patients with so-called Eales’ disease (group A); 30 positive controls with specific uveitis syndromes (group B), and 30 negative controls (group C). The undiluted vitreous humor samples were collected and subjected to real-time PCR assay for MPB64 gene of Mycobacterium tuberculosis (MTB) and load quantified. Results: Sixteen (57.14%) vitreous fluid samples in group A; 1 sample in group B, and none of the samples in group C were positive for MTB genome from the vitreous. The copies of MTB genomes in the positive samples in group A were 1.52 × 104 to 1.01 × 106. Conclusion: 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.

An outbreak of dengue fever in Periurban slums of Chandigarh India with special reference to entomological and climatic factors.

BACKGROUND Dengue viral infection is one of the most important public health problem in tropical countries. AIM An outbreak of dengue fever was investigated in a periurban slum area of Chandigarh, India, during September to December, 2002. MATERIALS AND METHODS Blood samples from 218 patients and 30 apparently healthy contacts were tested for dengue-specific immunoglobulin M (IgM) and IgG antibodies including 80 acute samples collected within 5 days of illness were subjected for virus isolation in newborn mice. The average temperature, rainfall, and humidity of the epidemic year were compared with the number of dengue cases. STATISTICAL ANALYSIS statistical significance was found out using c2-test. RESULTS A total of 76 cases were positive by either dengue IgM capture assay (n = 57) or virus isolation (n = 17) or both (n = 2). Fifteen of nineteen viral isolates subjected for typing by type-specific multiplex reverse transcription-polymerase chain reaction were found to be of dengue virus. High rainfall and humidity with the temperature range from 21 degrees C to 33 degrees C during the months of August and September might have favored the breeding of mosquitoes, thus leading to an increase in the number of dengue cases in October and November, 2002. CONCLUSION The present outbreak thus emphasizes the need for continuous sero epidemiological and entomological surveillance for the timely implementation of effective dengue control programme.

Does multiplex Polymerase Chain Reaction increase the diagnostic percentage in osteoarticular tuberculosis? A prospective evaluation of 80 cases

PurposeMultiplex Polymerase Chain Reaction (MPCR) is a technique in which two or more gene targets are amplified in a single reaction. This has increased sensitivity of diagnosis as a single gene target may be absent in some Mycobacterium tuberculosis strains.MethodsMPCR using two target genes specific for Mycobacterium tuberculosis, that is, IS6110 and MPB 64, ZN staining and Mycobacterial culture were performed on synovial fluid/pus samples of 80 (three confirmed, 77 suspected) patients of osteoarticular tuberculosis and 25 non tuberculosis patients.ResultsMPCR had a sensitivity of 100% in confirmed cases and 81.8% in clinically suspected cases. AFB was positive in one patient and Mycobacterial culture was positive in three patients. MPCR also had 100% specificity; MPB64 was positive in five patients in which IS6110 was negative whereas IS6110 was positive in two patients in which MPB64 was negative.ConclusionsMPCR is a sensitive and specific method for diagnosis of paucibacilliary conditions such as osteoarticular tuberculosis.

Evaluation of polymerase chain reaction using protein b primers for rapid diagnosis of tuberculous meningitis

BACKGROUND Rapid and specific diagnosis of tubercular meningitis (TBM) is of utmost importance. AIM To evaluate polymerase chain reaction (PCR) using protein b primers directed against M. tuberculosis for the diagnosis of tuberculous meningitis. MATERIALS AND METHODS PCR using protein b primers was performed in ten patients with confirmed TBM (culture positive), 60 patients with clinically suspected TBM and 40 patients with no TBM (control group). RESULTS Protein b PCR had a sensitivity of 90% and a specificity of 100% in patients with confirmed TBM. In 60 clinically diagnosed TBM patients, protein b PCR was positive in 49 (81.7%) patients. The overall sensitivity of microscopy, culture and PCR using protein b primers was 1.4%, 14.3%, and 82.8% and specificity was 100%, 100%, and 100% respectively. CONCLUSION Protein b PCR is valuable in rapid diagnosis of TBM.

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

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.

Development and evaluation of multiplex PCR in rapid diagnosis of abdominal tuberculosis

The clinical features of abdominal tuberculosis (TB) are non-specific and establishing a diagnosis remains a challenge. A delay in diagnosis is likely to increase the morbidity in these patients. We developed a multiplex polymerase chain reaction (PCR) using 16SrRNA, IS6110, and devR, and evaluated it in comparison with other conventional tests in clinical suspects of abdominal TB. A total of 183 patients with clinical suspicion of abdominal TB (96 patients with intestinal TB and 87 with peritoneal TB) were enrolled for the study. Endoscopic or intraoperative biopsies were collected from patients suspected of intestinal TB and ascitic fluid was collected from patients with a suspicion of peritoneal TB. Of the intestinal tuberculosis group, there were 40 confirmed cases and 56 controls, while of the peritoneal tuberculosis group there were 37 confirmed cases and 50 controls. Multiplex PCR showed a high sensitivity and specificity in both the intestinal TB and peritoneal TB groups. When combined with histopathology, multiplex PCR could detect 97.5% of all the cases in the intestinal tuberculosis group, while in combination adenosine deaminase levels (ADA) in cases of peritoneal tuberculosis it increased the specificity of diagnosis of peritoneal tuberculosis to 95%. In combination with histopathology in suspected intestinal TB cases, and ADA testing in suspected peritoneal TB cases, it can be used as a highly sensitive, specific, and rapid diagnostic tool with the ability to supplement the limitations of other diagnostic modalities.

Diagnosis of Ocular Tuberculosis

ABSTRACT Ocular tuberculosis remains a presumptive clinical diagnosis, as the gold standard tests for diagnosing ocular tuberculosis are often not useful: Mycobacterium tuberculosis cultures require weeks to process on Lowenstein–Jenson media and have low yield from ocular samples; while acid-fast bacilli smears or polymerase chain reaction detection of M. tuberculosis DNA have low sensitivities. Thus, diagnosis is often based on suggestive clinical signs, which are supported by positive investigations: tuberculin skin test or interferon-gamma release assays; chest X-ray findings suggestive of pulmonary tuberculosis, and/or evidence of associated systemic tuberculosis infections in the absence of other underlying disease. The aim of this review is to provide an update on the methods of diagnosing ocular tuberculosis, and discuss the challenges of its diagnosis. We also suggest a step-ladder approach to a more accurate diagnosis of ocular tuberculosis by combining the available diagnostic tests.