A low molecular weight ES-20 protein released in vivo and in vitro with diagnostic potential in lymph node tuberculosis

Purpose: To determine role of antigens released in vivo and in vitro in immunodiagnosis of tuberculosis (TB). Methods: In vivo released circulating tuberculosis antigen (CTA) was obtained from TB sera by ammonium sulphate precipitation and in vitro released excretory-secretory (ES) antigens from Mycobacterium tuberculosis culture filtrate. CTA and ES antigens were fractionated by SDS-PAGE and electro-eluted gel fractions were analysed for antigen by ELISA. Results: Low molecular weight proteins CTA-9 and ES-9 showed high titre of antigen activity. To explore the diagnostic potential of low molecular weight ES antigen, M. tuberculosis ES antigen was further fractionated by gel filtration chromatography followed by purification on anion exchange column using fast protein liquid chromatography and a highly seroreactive ESG-5D (ES-20) antigen was obtained. Competitive inhibition showed that CTA-9 and ES-9 antigens inhibit the binding of ES-20 antigen to its antibody. Seroanalysis showed sensitivity of 83 and 80% for ES-20 antigen and antibody detection, respectively, in pulmonary TB and 90% in lymph node TB. Conclusions: Seroreactivity studies using M. tuberculosis ES-20 antigen showed usefulness in detection of TB; in particular, lymph node TB

A Clinico- Epidemiological Study Of Filarial Related Orthopaedic Manifestations

An epidemiological study was undertaken to study the incidence and distribution of orthopaedic manifestations of filariasis in an endemic area. A total of 207 cases were clinically examined and investigated. Patients were divided into three groups , viz., Group A: Orthopaedic manifestations with no history of filariasis . Group B: Orthopaedic manifestations with history of filariasis such as microfilaraemia or filarial fevers etc., Group C: Orthopaedic manifestations with chronic manifestations such as elephantiasis, hydrocele etc. To confirm filarial etiology, all the cases were examined for the presence of filarial antibody by indirect ELISA using wuchereda bancrofti microfilarial excretory- secretary antigen (wd Mf ESAg) . A total of 61 of 102 patients of Group A, 14 of 21 patients of group B, and 73 of 84 patients of Group C were positive for filarial antibody. This study showed the prevalence of filarial antibody in about 71.4% of various orthopaedic manifestations

Improved laboratory diagnosis of tuberculosis – the Indian experience

Tuberculosis (TB) is the leading cause of death worldwide attributable to a single infectious disease agent. India has more new TB cases annually than any other country. In 2008, India accounted for a fifth of the estimated 9.4 million TB cases globally. There is an overwhelming need for improving TB diagnostics in India through the use of cost effective, patient-friendly methods appropriate to different tiers of the country health system. Substantial progress has been made in India in the field of TB diagnosis and serious efforts have been made to herald the development of diagnostic tests for pulmonary TB, extra pulmonary TB and MDR-TB. Diverse approaches have been attempted towards improving smear microscopy, rapid culture and for differentiation between the Mycobacterium tuberculosis complex and non-tuberculous mycobacteria. Several laboratories have developed in-house PCR assays for diagnosing TB with high accuracy. Approaches for distinguishing M. tuberculosis and/or Mycobacterium bovis infection and disseminated Mycobacterium avium complex infection in HIV-AIDS patients have also been described. Serological tests to detect antigens or antibodies to M. tuberculosis specific components by using cocktails of Excretory/Secretory protein antigens, Ag85 complex antigens, Hsp 65 antigen, RD1 antigens and Rapid Reverse Line Blot Hybridization assays to detect MDR-TB (mutations to rifampicin, isoniazid and streptomycin) have also been developed. Other methods like measurement of adenosine deaminase activity and use of luciferase reporter phages have also been explored for TB diagnosis. These advances in the Indian context are detailed in the present chapter. The validation and application of these methods in laboratory and public health settings is likely to result in improved TB diagnosis and contribute to effective disease management in India