MPT51 and MPT64-based antigen detection assay for the diagnosis of extrapulmonary tuberculosis from urine samples.

In view of WHO's "End-TB" strategy, we developed a non-invasive, urine-based ELISA, targeting 2 Mycobacterium tuberculosis antigens namely MPT51 and MPT64 for extrapulmonary TB (EPTB) diagnosis. Suspected EPTB patients (n = 137) [Pleural TB, Abdominal TB and Tuberculous meningitis] were categorized in "Definite" EPTB (n = 10) [Xpert-MTB/RIF and/or culture-positive], "Probable" EPTB (n = 77) and "Non-EPTB" (n = 50) groups using defined composite reference standards. ROC-curves were generated using ELISA results of "Definite" EPTB and "Non-EPTB" groups for both antigens independently and cut-off values were selected to provide 86.3% (95%CI:73.3-94.2) specificity for MPT51 and 92% (95%CI:80.8-97.8) for MPT64. The sensitivity of MPT51-ELISA and MPT64-ELISA was 70% (95%CI:34.7-93.3) and 90% (95%CI:55.5-99.7) for "Definite" EPTB group and 32.5% (95%CI:22.2-44.1) and 30.8% (95%CI:20.8-42.2) for "Probable" EPTB group, respectively. Combining the results of both ELISAs showed a 100% (95%CI:69.1-100) sensitivity in "Definite" EPTB group and 41.6% (95%CI:30.4-53.4) in "Probable" EPTB group, with an 80% (95%CI:66.3-89.9) specificity. The results demonstrated the potential of urine-based ELISAs as screening tests for EPTB diagnosis.

Utility of cell-free transrenal DNA for the diagnosis of Tuberculous Meningitis: A proof-of-concept study.

Tuberculous Meningitis (TBM) diagnosis remains a grave challenge. We evaluated the utility of extracellular vesicles (EVs) as a source of cell-free transrenal-mycobacterial DNA (cf-Tr-MTB DNA) for TBM diagnosis from urine samples. We developed a qPCR-assay targeting a highly repetitive 36-bp sequence specific to Mycobacterium tuberculosis complex. EVs were isolated from urine samples of suspected TBM groups (n = 44) [categorized using composite reference standard as 'Definite' TBM (n = 8), 'Probable' TBM (n = 15), 'Possible' TBM (n = 21)] and 'Non-TBM' group (n = 26). cf-Tr-MTB DNA-based qPCR assay was applied to DNA isolated from EVs (EV-DNA) and EV-free-fraction (EV-free DNA). ROC-curves were generated using qPCR results of 'Definite' TBM and 'Non-TBM' category in both EV-DNA and EV-free DNA samples and cut-off values were selected to provide 100% (95%CI:69.1-100) specificity. The cf-Tr-MTB DNA assay gave a sensitivity of 54.5% (95%CI:38.8-69.6) for EV-DNA and 77.3% (95%CI:62.1-88.5) for EV-free DNA in the TBM group (n = 44). The combination of EV-DNA and EV-free DNA results (corresponding to performance cf-Tr MTB DNA assay in urine), gave an overall sensitivity of 81.8% (95%CI:67.2-91.8) in the TBM group. Our results confirmed EVs as one of the sources of cf-Tr-MTB DNA and we believe the cf-Tr-MTB DNA-based qPCR assay has a potential application for TBM diagnosis.

Markers of subclinical atherosclerotic disease in HIV-infected individuals.

BACKGROUND: Wider access to antiretroviral treatment (ART) has resulted in a decline in the number of people dying due to AIDS-related causes. However, with this increased longevity, accelerated rates of cardiovascular and atherosclerotic diseases are on the rise. We hypothesised that the prevalence of atherosclerotic cardiovascular diseases is greater in HIV/AIDS patients as compared to the normal population. Thus, we aimed to study the predictors of subclinical atherosclerotic disease in HIV-infected individuals. METHODS: In total, 168 HIV-positive individuals below 45 years of age (124 [73.08%] on ART and 44 [26.2%] ART naive) along with 150 age- and sex-matched healthy controls were recruited for this cross-sectional observational study. Carotid intimal medial thickness (cIMT), a surrogate marker of atherosclerosis, was assessed by a carotid colour doppler ultrasound and a mean of four measurements (both sides) were taken. cIMT was correlated with the age of the individuals, duration and type of ART, duration of disease and the level of immunodeficiency (CD4 cell count) along with conventional cardiac risk markers. RESULTS: In 168 HIV-positive individuals, the mean CD4 cell count was 332.41 ±17.1 cells/mm3. The mean cIMT of all HIV-positive individuals was 0.712 ±0.039 mm (0.596-0.840 mm) as compared to 0.616 ±0.023 mm (0.540-0.655 mm) in HIV-negative individuals (P<0.001). cIMT in HIV-positive individuals on ART (subgroup A) was 0.723 ±0.034 mm as compared to 0.682 ±0.038 mm in HIV-positive individuals not on ART (subgroup B) (P<0.01). Low CD4 cell counts, longer duration of HIV infection, exposure to ART and longer duration of ART were found to be independent predictors of a higher cIMT in HIV-positive subjects whereas age, diastolic blood pressure, low HDL, smoking and high BMI were predictors of high cIMT in HIV-negative controls. No difference was observed in cIMT among patients on different ART regimens but individuals who were on nevirapine had higher cIMT as compared to those who were on efavirenz, both non-nucleoside reverse transcriptase inhibitors (NNRTIs). CONCLUSIONS: Individuals with HIV infection (whether on ART or ART naive) have higher cIMT, and therefore a higher atherosclerotic burden, as compared to HIV-negative individuals. HIV infection itself, along with ART, overshadows conventional cardiac risk markers as a predictor of atherosclerotic disease in these individuals.

Light Chain Myeloma induced Severe Hypertriglyceridemia.

Hyperlipidemia is very common in general population and incidence has further increased in recent years. Evaluation of patient presenting with lipid disorders is essential to obtain a definite diagnosis to prevent complications, and apply the most appropriate treatment. An isolated elevation in triglyceride levels may be caused by a primary disorder of lipid metabolism like familial hypertriglyceridemia. It may also arise secondary to a number of conditions like diabetes mellitus, alcohol intake, hypothyroidism, drugs, infections and nephrotic syndrome. Herein, we describe a case of secondary hypertriglyceridemia leading to Nonalcoholic Steatohepatitis (NASH) in a young female which was attributed to Multiple Myeloma (MM). Significant reduction in triglyceride levels after starting anti-myeloma therapy established their relation. This is the first case of light chain myeloma causing severe secondary hypertriglyceridemia.