Affiliations: School of Pathology and Laboratory Medicine,
University of Western Australia, Nedlands, Western Australia, Australia | School of Medicine and Pharmacology, University of
Western Australia, Nedlands, Western Australia, Australia
Note: [] Corresponding author: Dr. Andrew Lim, University of Western
Australia, School of Pathology and Laboratory Medicine, Level 2 MRF Building,
Rear of 50 Murray Street, Perth 6000, Western Australia. Tel.: +61 8 9224 0217;
Fax: +61 8 9224 0204; E-mail: andrew.lim@uwa.edu.au
Abstract: Lung disease due to non-tuberculous mycobacteria (NTM) is a poorly
understood condition that is difficult to treat. Treatment remains problematic
as few tools are available to help clinicians monitor disease progression or
predict treatment outcome. In this study, plasma levels of several inflammatory
molecules and the frequency of circulating T cell subsets were measured in
patients with NTM lung disease and known treatment status, and compared with
their adult offspring and with unrelated healthy controls. Plasma levels of the
chemokine CXCL10 and IL-18 were assessed for associations with treatment
efficacy. CXCL10 was higher in patients than adult offspring (p< 0.001) and
unrelated controls (p< 0.001). Plasma CXCL10 was also lower in patients who
responded well to therapy or who controlled their infection without requiring
therapy, when compared to patients who did not respond to therapy (p=0.03).
Frequencies of activated (HLA-DR^{+})
CD4^{+} T cells were higher in patients than adult offspring
(p<0.001) and unrelated controls (p<0.05), with the highest frequencies
in individuals who had completed at least 6 months of treatment. Frequencies of
activated (CD38^{+}) CD8^{+} T cells in
most treatment responders were similar to unrelated controls. Low plasma levels
of CXCL10 may reflect successful control of NTM lung disease with or without
therapy. Compared with responders, patients who responded poorly to treatment
generally had higher plasma levels of CXCL10 and IL-18, and higher frequencies
of activated CD8^{+} T cells.
Keywords: CXCL10, lung disease, non-tuberculous mycobacteria, T cells
