A Critical Appraisal of the Ban on Serological Tests for Tuberculosis Usefulness of Serological Monitoring of Tuberculosis Antibodies during the Treatment of TB Patients

Abstract

In 2011, the WHO banned the use of serological tests for the detection of antibodies against mycobacteria. This ban rests on a meta-analysis that observed a disparity in accuracy and specificity of results reported in various studies using this technique. All the included results were either level II observational studies or level III expert opinions. The immense majority of studies on other aspects of TB, as microscopy and vaccine efficacy, also pertain to these levels and present the same spread of results. The WHO policy statement rests on incorrect and invalid evidence. The experts analysed a pool of published studies of widely divergent quality, using different serological markers, and drew thereupon conclusions on quality of the serological test itself instead of on the quality of the studies analysed. In addition, the authors of the meta-analysis report results that are sometimes incorrect, drew conclusions on incomplete data, removed publications from their study using dubious reasons, lumped together results that should have been analysed separately and finally failed to take into consideration the value of the golden diagnostic methods used today. I intend to prove that serology is a very useful complementary tool in the diagnostic and prognostic of mycobacterial infections and that, had the WHO based their analysis on the complete information available, they would have supported the use of some serological tools for the diagnosis of TB instead of banning them.

PPE17 (Rv1168c) protein of Mycobacterium tuberculosis detects individuals with latent TB infection

“…In contrary, rapid diagnostic tests such as serological assays are considered to be simple and inexpensive methods of diagnosis. It is true that the serological test, especially in case of TB is very useful for rapid diagnosis, prognosis and also to follow-up patients [ 13 , 24 ]. Therefore, antibody-based diagnostic tests may be explored as an additional tool to screen LTBI subjects.…”

“…Proteins of Mtb are found to induce antibody responses in 90% of patients exposed to TB bacilli [ 11 ]. Due to simplicity and convenient detection of pathogens, low costs, easy operation and rapid determination, serological assays that measures antibody responses to selective Mtb antigens in suspected cases of TB are still considered to be attractive tools especially in resource limiting country like India [ 12 , 13 ]. In this direction, efforts were made globally to identify potential serodiagnostic antigens that induce strong antibody responses in TB patients.…”