RT Journal Article
SR Electronic
T1 Eosinophilia and predominant Th2 immune responses are rarely evident in disseminated tuberculosis
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP PA2704
DO 10.1183/13993003.congress-2016.PA2704
VO 48
IS suppl 60
A1 Paul Pfeffer
A1 Matthew Burman
A1 Valerie Milton
A1 Vishnu Naidu
A1 Devan Vaghela
A1 Heinke Kunst
YR 2016
UL http://erj.ersjournals.com/content/48/suppl_60/PA2704.abstract
AB Introduction: Although disseminated infection with Mycobacterium tuberculosis (TB) implies a major failure in the immune response, most patients with disseminated TB have no identifiable cause of immunodeficiency. Th2 inflammation, associated with asthma and allergy, inhibits Th1 and Th17 responses, both necessary for effective immune responses to TB. Th2 inflammation is known associated with disseminated Cryptococcal and Histoplasmosa infections. We therefore reviewed our cohort of HIV negative patients with disseminated TB for asthma or blood eosinophilia as a biomarker of unsuppressed Th2 inflammation.Methods: Our TB Registry was examined for cases of disseminated TB at Royal London and Newham Hospitals over the last 5 years. Full blood counts (with eosinophil counts) preceding diagnosis and commencement of anti-TB therapy were recorded, along with history of asthma or steroid therapy.Results: Full blood counts preceding anti-TB therapy were available in 31 patients with miliary/disseminated TB. 24 had undetectable eosinophils and only 3 a low-grade eosinophilia (0.4-0.5). 2 patients had asthma. 2 patients were on inhaled steroids (and 1 on oral steroids).Conclusion: We could find no evidence of frequent asthma or heightened Th2 immunity (high blood eosinophils) in disseminated TB. It is possible that measuring blood counts at time of presentation is too late to detect any eosinophilia present earlier when they first acquired TB and failed to mount an early effective immune response. The eosinopaenia in these patients may reflect Th1 immune responses suppressing Th2 responses, and there is limited evidence that BCG vaccination may be able to suppress asthmatic inflammation.