Many other infectious diseases with local and systemic symptoms of TB are caused by the growth of
M. tuberculosis and the host’s inflammatory response to the presence of the bacteria in the tissue
[81][29]. TB infection initiates an inflammatory immune response that causes tissue damage. In addition, active TB infection by itself appears to be an immunosuppression factor, via the modification of the immune response, which favors the long-term persistence of the bacteria in the tissue
[82,83][30][31]. Hence, during adequate sterilizing antimycobacterial treatment, immunopathological reactions, due to gradual restoration of pathogen-specific immune responses, may occur with paradoxical worsening and upgrading clinical reactions
[84][32]. However, these paradoxical reactions during TB treatment occurred less frequently, and with less exaggeration, than immune reconstitution inflammatory syndrome with dynamics of rapid immune restoration in immunocompromised individuals
[85][33], such as HIV-infected subjects on antiretroviral therapy
[15][34]. These paradoxical clinical worsening in non-HIV-patients, generally self-limited, are more common in lymph node TB, consistent with exacerbation of pain and swelling following the initiation of chemotherapy
[85][33]. In addition, age was not found to predict the occurrence of paradoxical upgrading reactions in a retrospective analysis
[86][35]. Adjunctive transient corticosteroid therapy may be used to treat paradoxical upgrading reactions. Frequent complications associated with corticosteroid therapy among the elderly (osteoporosis with osteoporotic fractures, falls or osteoarticular problems, protein-energy malnutrition, amyotrophy, and psychiatric complications) should be prevented and treated because they may have serious consequences in this frail population
[87][36]. Attention should be paid to the prescription of preventive measures through comprehensive care.
4. Conclusions
Tuberculosis in the elderly is not a rare infection and requires special management. If the immunosenescence mainly favors the reactivation of the infection, whether or not aggravated by potential associated treatments (corticosteroids, immunosuppressants, anticancer chemotherapy), the search for HIV infection must be systematic. The average age of discovery of HIV is progressing by year after year, specially in high-income countries. The treatment of TB in the elderly is complex, combining the initial constraints of respiratory isolation and contact screening, often in long-term care facilities, and a prolonged use of combinations of anti-tuberculosis drugs that are potentially toxic and induce drug-drug interactions, in the context of often precarious general condition (undernutrition, co-morbidities, cognitive disorders) due both to active systemic infection and to old age. Multidisciplinary management, associating geriatricians and infectious disease specialists, based on close collaboration is justified throughout care to optimize a favorable outcome in these vulnerable patients.