A new study led by researchers at Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh School of Medicine published in the online version of the Journal of Clinical Investigation on January 2, 2013, is the first to identify a biological marker that differentiates active tuberculosis from latent tuberculosis and to identify a marker molecule that restores inactivity to active TB in animals.
The researchers found that the difference between a functioning protective granulomae, as in latent TB, and a non-protective granuloma seen in active TB patients is that that granulomas that contain ectopic lymphoid structures, which resemble lymph nodes, are associated with effective suppression of TB, and that granulomas that don't contain them are associated with active TB.
Immune cells (T cells) had a surface marker molecule called CXCR5 were associated with the presence of ectopic lymphoid structures. Without CXCR5, latent TB becomes active.
The researchers delivered CXCR5 T cells from donor animals to TB-infected mice that lacked CXCR5. T cell localization and ectopic lymphoid structure formation were restored leading to decreased susceptibility to TB.
Two billion people have latent TB at present. The instance of TB in Alabama rose from 146 cases in 2010 to 161 cases in 2011 in Alabama according to the Alabama Department of Public Health. A vaccine would reduce the costs of long term difficult treatment of an ultimately deadly disease.
The research was reviewed at the Eureka Alert website the date of publication.