Biomedical subjects

Vijay K Arora

Publications and source records attributed to Vijay K Arora.

4 recordsLinked to original sources

PubMed2005

Antigens of Mycobacterium tuberculosis recognized by antibodies during incipient, subclinical tuberculosis.

Serum samples obtained from human immunodeficiency virus (HIV)-infected tuberculosis (TB) patients months prior to clinical TB were used to delineate the profile of Mycobacterium tuberculosis culture filtrate proteins recognized during subclinical TB. A subset of approximately 12 antigens was recognized by antibodies in these serum samples. Antibodies to two of these antigens (81 [88]-kDa malate synthase [GlcB] and MPT51) were present in serum samples obtained during incipient subclinical TB in 19 (approximately 90%) of the 21 HIV-infected TB patients tested. These antigens will be useful for devising diagnostic tests that can identify HIV-positive individuals who are at a high risk for developing clinical TB.

Antibodies, Bacterial↗

PubMed2005

Immunogenicity of the Mycobacterium tuberculosis PPE55 (Rv3347c) protein during incipient and clinical tuberculosis.

Clinical tuberculosis (TB), whether noncavitary or cavitary, is the late stage of a chronic disease process, since Mycobacterium tuberculosis is a slowly growing organism. Our studies have shown that the profiles of antigenic proteins expressed by the in vivo bacteria that elicit antibodies differ in cavitary and noncavitary TB. To gain insight into antigenic proteins expressed during incipient, subclinical TB, an expression library of M. tuberculosis genomic DNA was screened with sera obtained during subclinical TB from guinea pigs infected with aerosols of M. tuberculosis H37Rv. One of the proteins recognized by antibodies elicited during subclinical TB infection of guinea pigs is the 309-kDa PPE55 (Rv3347c) protein. Genomic hybridization studies suggest that the PPE55 gene is specific to the M. tuberculosis complex and is present in a majority of clinical isolates tested. Antibodies to the C-terminal, approximately 100-kDa fragment of PPE55 (PPE-C) were detectable in sera from 29/30 (97%) human immunodeficiency virus-negative/TB-positive (HIV(-) TB(+)) patients and 17/24 (71%) HIV(+) TB(+) patients tested but not in sera from purified-protein derivative-positive healthy controls, suggesting that the in vivo expression of PPE55 protein correlates with active M. tuberculosis infection. Anti-PPE-C antibodies were also detected in retrospective sera obtained months prior to manifestation of clinical TB from 17/21 (81%) HIV(+) TB(+) individuals tested, providing evidence that the protein is expressed during incipient, subclinical TB in HIV-infected humans. Thus, PPE55 is a highly immunogenic protein that may be useful for differentiating between latent TB and incipient, subclinical TB.

Animals↗

PubMed2004

Public-private mix for DOTS implementation: what makes it work?

OBJECTIVE: To compare processes and outcomes of four public-private mix (PPM) projects on DOTS implementation for tuberculosis (TB) control in New Delhi, India; Ho Chi Minh City, Viet Nam; Nairobi, Kenya; and Pune, India. METHODS: Cross-project analysis of secondary data from separate project evaluations was used. Differences among PPM project sites in impact on TB control (change in case detection, treatment outcomes and equity in access) were correlated with differences in chosen intervention strategies and structural conditions. FINDINGS: The analysis suggests that an effective intervention package should include the following provider-side components: (1) orienting private providers (PPs) and the staff of the national TB programme (NTP); (2) improving the referral and information system through simple practical tools; (3) the NTP adequately supervising and monitoring PPs; and (4) the NTP providing free anti-TB drugs to patients treated in the private sector. CONCLUSION: Getting such an intervention package to work requires that the NTP be strongly committed to supporting, supervising and evaluating PPM projects. Further, using a local nongovernmental organization or a medical association as an intermediary may facilitate collaboration. Investing time and effort to ensure that sufficient dialogue takes place among all stakeholders is important to help build trust and achieve a high level of agreement.

Communicable Disease Control↗

PubMed2003

Combined use of serum and urinary antibody for diagnosis of tuberculosis.

Efforts to devise immunoassays for tuberculosis (TB) that can be adapted to rapid formats are ongoing. The present study was aimed at determining whether urinary anti-Mycobacterium tuberculosis antibodies are present in patients with TB, to evaluate the feasibility of developing a urine antibody-based diagnostic test. Urinary antibodies directed against the culture filtrate proteins of M. tuberculosis, MPT 32, and the 81-kDa GlcB protein were detectable in patients with TB, although the sensitivity of antibody detection was lower (53%-64%), compared with serum antibodies (68%-77%). Surprisingly, with all 3 antigens, the use of paired serum and urine samples provided higher sensitivities of antibody detection than either single specimen, and anti-GlcB antibodies were present in the serum and/or urine of 39 (90%) of 43 smear-positive patients with TB. Although, with the current methods and antigens, the level of sensitivity is insufficient to design a urinary antibody diagnostic test, these studies provide the foundation for further studies on the development of a urine antibody-based immunoassay for TB.

Adult↗