Abstract
We previously found that a subset of patients with pulmonary non-tuberculous mycobacterial (pNTM) disease were taller, leaner, and had a higher prevalence of pectus excavatum and scoliosis than uninfected controls. Additionally, whole blood of pNTM patients stimulated ex vivo with live Mycobacterium intracellulare produced significantly less interferon-gamma (IFNγ) compared to that of uninfected controls. Since IFNγ production can be suppressed by transforming growth factor-beta (TGFβ), an immunosuppressive cytokine, we measured basal and M. intracellulare-stimulated blood levels of TGFβ in a group of 20 pNTM patients and 20 uninfected controls. In contrast to the IFNγ findings, we found that stimulated blood from pNTM patients produced significantly higher levels of TGFβ compared to controls. Since pNTM patients frequently possess body features that overlap with Marfan syndrome (MFS), and increased TGFβ expression is important in the pathogenesis of MFS, we posit that a yet-to-be-identified syndrome related to MFS predisposes certain individuals to develop pNTM disease.
Acknowledgements
We thank Dr Leonid Heifets for providing the Mycobacterium intracellulare isolate used in the ex vivo experiments. We are also grateful to the pNTM patients and control subjects who participated in the study.
Declaration of interest: All the authors have no conflict of interest regarding the content of this manuscript. This work was supported in part by the kind support of Fern and Phil Leitman of Non-tuberculous Mycobacteria Info and Research (NTMir) of Miami, Florida. Supported in part by NIH/NCRR Colorado CTSI Grant Number UL1 RR025780. The contents are the authors’ sole responsibility and do not necessarily represent official NIH views.