Immune Tuberculous Anergy: A Brief Mechanistic Overview
Ibrahim M. S. Shnawa *
Department of Medical Biotechnology, College of Biotechnology, AL-Qasim Green University, Iraq and Department of Dental Technology, College of Health and Medical Technology, University of Hilla, Babylon, Iraq.
*Author to whom correspondence should be addressed.
Abstract
Immune tuberculous anergy represents a state of reduced immune responsiveness, expressed clinically by negative delayed-type hypersensitivity responses and functionally by impaired lymphocyte proliferation and altered cytokine production. This chapter provides a mechanistic overview of immune anergy, with emphasis on tuberculosis and related chronic intracellular microbial infections. It summarises immune anergy as a cellular and molecular process involving T- and B-lymphocyte dysfunction, defective co-stimulatory signaling, altered T-cell receptor signaling, reduced interleukin-2 production, increased regulatory influences, and possible impairment of lymphocyte immunometabolism. The chapter also compares anergic B cells, anergic T cells, exhausted T cells, immune tolerance, and immune resilience, noting shared features such as hyporesponsiveness and reduced effector function while recognising differences in induction pathways, transcriptional patterns, and cell fate. A possible protective role of immune anergy in graft acceptance and prevention of autoimmune responses is also described. The manuscript further summarize a local clinical program involving 125 human subjects, including 25 normal controls, 50 tuberculin-positive pulmonary tuberculosis patients, and 50 tuberculin-negative tuberculosis patients aged 25 to 65 years. The evaluated cellular immune parameters included nitro-blue tetrazolium reduction, leukocyte inhibitory factor response, and total T-cell E-rosette counts. In the summarized observations, tuberculin-negative tuberculosis patients showed clinical and cellular evidence of anergy, with reduced adaptive cellular immune activity and preserved innate cellular function compared with tuberculin-positive tuberculosis patients. Overall, the chapter frames immune tuberculous anergy as a clinically relevant form of immune hypo-responsiveness linked to chronic infection, immune tolerance, lymphocyte signalling, and immune-metabolic disturbance.
Keywords: Anergy, adaptive cellular immunity, B-cell anergy, delayed-type hypersensitivity, immune exhaustion, immune tolerance, immune-metabolism, lymphocyte signalling, tuberculin negativity, tuberculosis