Severe Pulmonary Arterial Hypertension Is Characterized by Increased Neutrophil Elastase and Relative Elafin Deficiency.

"Financial/nonfinancial disclosures: The authors have reported to CHEST the following: M. R. and R. T. Z. lead an investigator-initiated phase 1 clinical trial evaluating the safety and tolerability of subcutaneous Elafin. C. J. R. received personal fees from United Therapeutics and Jannsen Pharmaceuticals outside the submitted research. E. S. served as a scientific advisor for Selten Pharma, Inc., outside the submitted work. None declared (A. J. S., S. T., P. A. D. R., A. H., F. H., M. B.-R., R. D. B., S. G., M. R. W., N. W. M., M. R. N.)."

"FUNDING/SUPPORT : This study was supported primarily by the 10.13039/100000002National Institutes of Health (NIH) [Grant P01 HL108797]. A. J. S. is supported by the 10.13039/100000050National Heart, Lung, and Blood Institute of the NIH [Grant 1K23HL151892] and the American Thoracic Society Foundation / 10.13039/100002291Pulmonary Hypertension Association Research Fellowship. E. S. is supported by the 10.13039/100000050National Heart, Lung, and Blood Institute of the NIH. K. M. received grant support from the 10.13039/501100013642Japan Heart Foundation / 10.13039/100015731Bayer Yakuhin Research Grant Abroad and the 10.13039/100008732Uehara Memorial Foundation during conduct of the study. E. M. S. received grant support from the 10.13039/501100000274British Heart Foundation and 10.13039/501100000265Medical Research Council during conduct of the study. Data were shared from the UK National Cohort Study of Idiopathic and Heritable PAH, which is supported by the National Institute of 10.13039/100005622Health Research BioResource, the 10.13039/501100000274British Heart Foundation [Grant SP/12/12/29836], and the UK 10.13039/501100000265Medical Research Council [Grant MR/K020919/1]. The study used human lung tissue obtained through the Pulmonary Hypertension Breakthrough Initiative, which is supported by the 10.13039/100000002National Institutes of Health [Grant R24 HL123767] and the Cardiovascular and Medical Research and Education Foundation."