Detection and quantification of Mycobacterium tuberculosis antigen CFP10 in serum and urine for the rapid diagnosis of active tuberculosis disease

Outside of the ongoing COVID-19 pandemic, tuberculosis is the leading cause of infectious disease mortality globally. Currently, there is no commercially available point-of-care diagnostic that is rapid, inexpensive, and highly sensitive for the diagnosis of active tuberculosis disease. Here we describe the development and optimization of a novel, highly sensitive prototype bioelectronic tuberculosis antigen (BETA) assay to detect tuberculosis-specific antigen, CFP10, in small-volume serum and urine samples. In this proof-of-concept study we evaluated the performance of the BETA assay using clinical specimens collected from presumptive tuberculosis patients from three independent cohorts. Circulating CFP10 antigen was detected in ALL serum (n = 19) and urine (n = 3) samples from bacteriologically confirmed tuberculosis patients who were untreated or had less than one week of treatment at time of serum collection, successfully identifying all culture positive tuberculosis patients. No CFP10 antigen was detected in serum (n = 7) or urine (n = 6) samples from individuals who were determined to be negative for tuberculosis disease. Additionally, antigen quantification using the BETA assay of paired serum samples collected from tuberculosis patients (n = 8) both before and after treatment initiation, indicate consistently declining within-person levels of CFP10 antigen during treatment. This novel, low-cost assay demonstrates potential as a rapid, non-sputum-based, point-of-care tool for the diagnosis of tuberculosis disease.

Application value of tissue tuberculosis antigen combined with Xpert MTB/RIF detection in differential diagnosis of intestinal tuberculosis and Crohn’s disease

Background: The purpose of this study was to evaluate the value of Xpert MTB/RIF detection and tuberculosis antigen detection of Mycobacterium tuberculosis cluster (MTBC) in intestinal tissues for differentiating intestinal tuberculosis (ITB) from Crohn’s disease (CD). Methods: A total of 110 patients who were clinically diagnosed with CD or ITB were monitored. Several specimens of intestinal tissue from endoscopic biopsy or surgical excision were used for culture and Xpert MTB/RIF for detection of MTBC, respectively. Four antigens (38KDa, ESAT-6, MPT64, Ag85 complex) of MTBC in intestinal tissue were detected by immunohistochemistry. Results: A total of 42 cases of intestinal tuberculosis and 46 cases of CD were included in the experimental analysis. Perianal lesions and longitudinal ulcers were more common in CD patients (p < 0.05), while caseous granuloma and annular ulcers were more common in ITB patients (P < 0.05). The positive rate of MTBC detected by Xpert MTB/RIF in intestinal tissue samples of ITB patients was 33.33%, which was significantly higher compared to CD patients (p < 0.05) and compared to acid-fast staining smears (9.52%) (p < 0.05). The positive MPT64 expression rate in patients with intestinal tuberculosis was 40.48%, which was significantly higher than that observed in CD patients, which was 19.56% (p<0.05). Conclusions: The detection of Xpert MTB/RIF in intestinal tissue is a rapid and useful method for establishing an early diagnosis of intestinal tuberculosis. The detection of Xpert MTB/RIF and MPT64 antigen in intestinal tissues have definitive value in the differential diagnosis of intestinal tuberculosis and Crohn’s disease. The combination of these two methods could improve detection sensitivity.

Application value of tissue tuberculosis antigen combined with Xpert MTB/RIF detection in differential diagnosis of intestinal tuberculosis and Crohn’s disease

Abstract Background: The purpose of this study was to evaluate the value of Xpert MTB/RIF detection and tuberculosis antigen detection of Mycobacterium tuberculosis (MTB) in intestinal tissues for differentiating intestinal tuberculosis (ITB) from Crohn’s disease (CD). Materials and Methods: A total of 110 patients who were clinically diagnosed with CD or ITB were monitored. Several specimens of intestinal tissue from endoscopic biopsy or surgical excision were used for MTB culture and Xpert MTB/RIF detection, respectively. Four antigens (38KDa, ESAT-6, MPT64, Ag85 complex) of MTB in intestinal tissue were detected by immunohistochemistry. Results: A total of 42 cases of intestinal tuberculosis and 46 cases of CD were included in the experimental analysis. Perianal lesions and longitudinal ulcers were more common in CD patients (p < 0.05), while caseous granuloma and annular ulcers were more common in ITB patients (P < 0.05). The positive rate of M. tuberculosis detected by Xpert MTB/RIF in intestinal tissue samples of ITB patients was 33.33%, which was significantly higher compared to CD patients (p < 0.05) and compared to acid-fast staining smears (9.52%) (p < 0.05). The positive MPT64 expression rate in patients with intestinal tuberculosis was 40.48%, which was significantly higher than that observed in CD patients, which was 19.56% (p<0.05). Conclusions: The detection of Xpert MTB/RIF in intestinal tissue was conducive to the quick and early diagnosis of intestinal tuberculosis. Xpert MTB/RIF and MPT64 antigen in intestinal tissues had certain value in the differential diagnosis of intestinal tuberculosis and Crohn’s disease. The combination of these two methods could improve detection sensitivity.

COMPARATIVE ASSESSMENT OF BIOCHEMICAL AND IMMUNOLOGICAL MARKERS IN TUBERCULOSIS

Introduction: Pulmonary tuberculosis is major public health problem in developing countries like India.Millions of people have died from tuberculosis. Many times it is difficult to get sputum sample from the patients. Some tests lack specificity, some other lack sensitivity. Hence, there is need of precise and faster diagnosis for patients attending hospitals. In this study, we compared the detection potential of biochemical and immunological markers(ADA, LDH and Mycobacterium tuberculosis H37Ra ES-31 & EST-6 antigens & antibodies based ELISAs) in pulmonary tuberculosis. Methods: 50 pulmonary tuberculosis cases confirmed by sputum examinationfor acid fast bacilli (AFB) and 50 age and sex matched control subjects were included in this study.ADA & LDH were estimated by using commercial kits. Tubercular antigens and antibodies were detected by ELISA method. Results: SerumADA detected pulmonary tuberculosis with sensitivityand specificityof 94%. Sensitivity and specificity of serum LDH in detecting pulmonary tuberculosis was found to be 94% and 36% respectively.Serumtubercular antigens detected pulmonary tuberculosis with sensitivity and specificity of 88%. Sensitivity and specificity of serum tubercular antibodies in detecting pulmonary tuberculosis was found to be 80% and 90% respectively. Conclusion: Adenosine deaminase has better detection potential over other markers in pulmonary tuberculosis. Keywords: Adenosine deaminase, Lactate dehydrogenase, Tuberculosis antigen-antibody