Dipstick urinalysis for diabetes screening in TB patients.

INTRODUCTION: Diabetes knowledge among TB patients can contribute to improved TB treatment outcomes, but lack of diabetes diagnosis awareness is a limitation in developing countries. Given its low cost, the sensitivity of urine glucose dipsticks for diabetes screening in TB patients was assessed. METHODS: Glycosuria was assessed in 90 newly diagnosed TB patients (38 with diabetes) in south Texas, USA (n = 20) and northeast Mexico (n = 70) during January 2009-December 2010. RESULTS: Glycosuria was detected in 65% of the diabetic patients with chronic hyperglycemia (positive predictive value 91%, negative predictive value 84%). CONCLUSION: We propose that TB clinics with limited budgets where portable glucometers may not be available conduct universal screening for diabetes with urine dipsticks. This could be followed by blood glucose or HbA1c testing in the subset of patients requiring confirmation or higher sensitivity assessment, to improve the comanagement of TB and diabetes.

Validation of Mycobacterium tuberculosis Rv1681 protein as a diagnostic marker of active pulmonary tuberculosis.

The development of an accurate antigen detection assay for the diagnosis of active tuberculosis (TB) would represent a major clinical advance. Here, we demonstrate that the Mycobacterium tuberculosis Rv1681 protein is a biomarker for active TB with potential diagnostic utility. We initially identified, by mass spectroscopy, peptides from the Rv1681 protein in urine specimens from 4 patients with untreated active TB. Rabbit IgG anti-recombinant Rv1681 detected Rv1681 protein in lysates and culture filtrates of M. tuberculosis and immunoprecipitated it from pooled urine specimens from two TB patients. An enzyme-linked immunosorbent assay formatted with these antibodies detected Rv1681 protein in unconcentrated urine specimens from 11/25 (44%) TB patients and 1/21 (4.8%) subjects in whom TB was initially clinically suspected but then ruled out by conventional methods. Rv1681 protein was not detected in urine specimens from 10 subjects with Escherichia coli-positive urine cultures, 26 subjects with confirmed non-TB tropical diseases (11 with schistosomiasis, 5 with Chagas' disease, and 10 with cutaneous leishmaniasis), and 14 healthy subjects. These results provide strong validation of Rv1681 protein as a promising biomarker for TB diagnosis.

Cross-sectional assessment reveals high diabetes prevalence among newly-diagnosed tuberculosis cases.

OBJECTIVE: To estimate the contribution of clinically-confirmed diabetes mellitus to tuberculosis (TB) rates in communities where both diseases are prevalent as a way to identify opportunities for TB prevention among diabetic patients. METHODS: This is a prospective study in which TB patients ≥ 20 years old at TB clinics in the Texas-Mexico border were tested for diabetes. The risk of tuberculosis attributable to diabetes was estimated from statistics for the corresponding adult population. FINDINGS: The prevalence of diabetes among TB patients was 39% in Texas and 36% in Mexico. Diabetes contributed 25% of the TB cases studied, whereas human immunodeficiency virus (HIV) infection contributed 5% or fewer. Among TB patients, fewer Mexicans than Texans were aware that they had diabetes before this study (4% and 19%, respectively). Men were also less frequently aware than women that they had diabetes (P = 0.03). Patients who knew that they had diabetes before the study had an 8-year history of the disease, on average, before being diagnosed with TB. CONCLUSION: Patients with diabetes are at higher risk of contracting TB than non-diabetic patients. Integrating TB and diabetes control programmes worldwide would facilitate TB prevention among diabetes patients and increase the number of diabetics who learn of their condition, particularly among males. Such a strategy would lead to earlier case detection and improve the management of both TB and diabetes.