Behçet's disease with latent Mycobacterium tuberculosis infection

Neuro-Behçet's Disease Onset in the Context of Tuberculous Meningoencephalitis: A Case Report

Behçet's disease (BD) is a systemic vasculitis that frequently presents with a relapsing-remitting pattern. CNS involvement (Neuro-Behçet) is rare, affecting approximately 10% of patients. Its etiological mechanisms are not yet fully understood. The most commonly accepted hypothesis is that of a systemic inflammatory reaction triggered by an infectious agent or by an autoantigen, such as heat shock protein, in genetically predisposed individuals. Mycobacterium tuberculosis is known to be closely interconnected with BD, both affecting cell-mediated immunity to a certain extent and probably sharing a common genetic background. We present the case of a 34-year-old Caucasian woman who had been diagnosed with tuberculous meningitis 15 months prior, with significant neurological deficits and lesional burden on MRI with repeated relapses whenever treatment withdrawal was attempted. These relapses were initially considered as reactivation of tuberculous meningoencephalitis, and symptoms improved after a combination of antituberculous treatment and corticosteroid therapy. After the second relapse, the diagnosis was reconsidered, as new information emerged about oral and genital aphthous lesions, making us suspect a BD diagnosis. HLA B51 testing was positive, antituberculous treatment was stopped, and the patient was started on high doses of oral Cortisone and Azathioprine. Consequently, the evolution was favorable, with no further relapses and slow improvements in neurological deficits. To our knowledge, this is the first report of Neuro-Behçet's disease onset precipitated by tuberculous meningitis. We include a review of the available literature on this subject. Our case reinforces the fact that Mycobacterium tuberculosis infection can precipitate BD in genetically predisposed patients, and we recommend HLA B51 screening in patients with prolonged or relapsing meningoencephalitis, even if an infectious agent is apparently involved.

Infectious agents and pathogenesis of Behçet's disease: An extensive review

Behçet's disease (BD) is a multisystemic chronic vasculitis. Sustained and enhanced immune responses were reportedly associated with active BD. Although genetic polymorphisms increase development risk, genetic factors alone cannot account for BD development, suggesting the involvement of exogenous factors. Also, how various infectious agents promote BD in high-risk populations is not fully understood. In this review, we summarized the current findings on the associations of infectious agents with BD pathogenesis. The review also highlights the potential microbial risk factors and their pathogenic role in BD progression. Interactions between genetic and infectious risk factors was also discussed. Furthermore, evidence implied that after the eradication of infectious agents, BD symptoms and recurrence decreased, thus highlighting that combined use of antibiotics may be an effective therapy for BD. Finally, we summarized the main limitation of the current related studies, providing valuable insights and a basis for future studies on BD pathogenic factors.

The Biological and Clinical Aspects of a Latent Tuberculosis Infection

Tuberculosis (TB), caused by bacilli from the Mycobacterium tuberculosis complex, remains a serious global public health problem, representing one of the main causes of death from infectious diseases. About one quarter of the world’s population is infected with Mtb and has a latent TB infection (LTBI). According to the World Health Organization (WHO), an LTBI is characterized by a lasting immune response to Mtb antigens without any TB symptoms. Current LTBI diagnoses and treatments are based on this simplified definition, although an LTBI involves a broad range of conditions, including when Mtb remains in the body in a persistent form and the immune response cannot be detected. The study of LTBIs has progressed in recent years; however, many biological and medical aspects of an LTBI are still under discussion. This review focuses on an LTBI as a broad spectrum of states, both of the human body, and of Mtb cells. The problems of phenotypic insusceptibility, diagnoses, chemoprophylaxis, and the necessity of treatment are discussed. We emphasize the complexity of an LTBI diagnosis and its treatment due to its ambiguous nature. We consider alternative ways of differentiating an LTBI from active TB, as well as predicting TB reactivation based on using mycobacterial “latency antigens” for interferon gamma release assay (IGRA) tests and the transcriptomic analysis of human blood cells.