[Paradoxical tuberculosis reaction]. / Réaction paradoxale tuberculeuse.

Paradoxical tuberculosis reaction is defined as the aggravation of lesions present at diagnosis or the development of new lesions under anti-tuberculosis treatment, after exclusion of other alternate causes. It affects 5 to 30% of tuberculosis patients, with a variable prevalence depending on the site of infection and the clinical background. The diagnosis of paradoxical reaction is one of elimination, and requires having ruled out therapeutic failure, notably linked to poor compliance and/or to the presence of mycobacterial antibiotic resistance. The severity of paradoxical tuberculosis reaction lies in its neurological impairment. Despite its clinical importance, the mechanisms involved remain poorly understood and its management is not consensual. Corticosteroids are the cornerstone in the medical management. The role of anti-TNF agents, currently proposed in cases of corticodependence or corticoresistance, remains to be properly defined.

Immune response to pertussis vaccine in COPD patients.

Exacerbation triggered by respiratory infection is an important cause of morbidity and mortality in chronic obstructive pulmonary disease (COPD) patients. Strategies aiming to preventing infection may have significant public health impact. Our previous study demonstrated decreased immunological response to seasonal flu vaccination in COPD patients, questioning the efficiency of other vaccines in this group of patients. We performed a prospective, monocenter, longitudinal study that evaluated the humoral and cellular responses upon pertussis vaccination. We included 13 patients with stable COPD and 8 healthy volunteers. No difference in circulating B and T cell subsets at baseline was noted. Both groups presented similar levels of TFH, plasmablasts and pertussis specific antibodies induction after vaccination. Moreover, monitoring T cell immunity after ex-vivo peptide stimulation revealed equivalent induction of functional and specific CD4+ T cells (IFNγ, TNFα and IL-2-expressing T cells) in both groups. Our results highlight the immunological efficiency of pertussis vaccination in this particularly vulnerable population and challenge the concept that COPD patients are less responsive to all immunization strategies. Healthcare providers should stress the necessity of decennial Tdap booster vaccination in COPD patients.