Gene Signature Blood Test Can Diagnose TB and Treatment Response

MedicalResearch.com Interview with:
"Mycobacterium tuberculosis Bacteria, the Cause of TB" by NIAID is licensed under CC BY 2.0Purvesh Khatri, Ph.D.
Associate Professor
Stanford Institute for Immunity, Transplantation and Infection (ITI)
Stanford Center for Biomedical Informatics Research (BMIR)
Department of Medicine
Stanford University
Stanford, CA 94305

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: We have previously described a 3-gene signature for distinguishing patients with active tuberculosis (ATB) from those with other diseases, latent mycobacterium tuberculosis (LTB) infection, and healthy controls (Sweeney et al. Lancet Respir Med 2016).

The current study in JAMA Network Open is a follow up study to validate the 3-gene signature in 3 additional independent cohorts that were prospectively collected.

Using these 3 cohorts we have now showed that the 3-gene signature

(1) can identify patients with LTB that will progress to ATB about 6 months prior to diagnosis of active tuberculosis.

(2) can identify patients with ATB in active screening, and

(3) can identify patients with ATB at diagnosis that have higher likelihood of persistent lung inflammation due to subclinical ATB at the end of treatment.  Continue reading

Inhaled Steroids Associated With Increased Risk of Atypical Mycobacterial Infections

MedicalResearch.com Interview with:

Stephen J Ruoss MD Professor, Stanford University, Medicine, Division of Pulmonary and Cfritical Care Medicine Stanford, California

Dr. Ruoss

Stephen J Ruoss MD
Professor, Stanford University, Medicine,
Division of Pulmonary and Cfritical Care Medicine
Stanford, California

MedicalResearch.com: What is the background for this study? Would you briefly explain what is meant by an atypical mycobacterial infection? 

Response: Our interest in undertaking this study stems from three important clinical observations and issues.

First, the use of inhaled steroid medications for a broad variety of respiratory complaints and diseases is increasing, including in clinical circumstances where there isn’t much strong supportive evidence for benefit to patients from using inhaled steroids.

The second observation is that steroids can and do alter immune system responses, and can increase the risk for some infections. There are already data from studying patients on inhaled steroids where the incidence of bacterial respiratory infections has increased, supporting the concerns for infection risk from inhaled steroids.

And the third issue is that steroids can more specifically alter immune system function that helps combat mycobacterial infections, and this means that the risk for, and incidence of mycobacterial infections could be increased in patients treated with inhaled steroids. The best known mycobacterial infection is of course tuberculosis, but there are other mycobacteria, called nontuberculous mycobacterial (or atypical mycobacterial) that are broadly found in the environment, and some of those nontuberculous mycobacteria (NTM) can cause lung infections.

So our hypothesis was that the use of inhaled steroids might be associated with an increased frequency of NTM infections, and we designed the study to explore that hypothesis. Continue reading