RT Journal Article
SR Electronic
T1 Shrinking Lung Syndrome as a Manifestation of Pleuritis: A New Model Based on Pulmonary Physiological Studies
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP jrheum.121048
DO 10.3899/jrheum.121048
A1 Lauren A.  Henderson
A1 Stephen H.  Loring
A1 Ritu R.  Gill
A1 Katherine P.  Liao
A1 Rumey Ishizawar
A1 Susan Kim
A1 Robin Perlmutter-Goldenson
A1 Deborah Rothman
A1 Mary Beth F.  Son
A1 Matthew L.  Stoll
A1 Lawrence S.  Zemel
A1 Christy Sandborg
A1 Paul F.  Dellaripa
A1 Peter A.  Nigrovic
YR 2013
UL http://www.jrheum.org/content/early/2013/01/27/jrheum.121048.abstract
AB Objective The pathophysiology of shrinking lung syndrome (SLS) is poorly understood. We sought to define the structural basis for this condition through the study of pulmonary mechanics in affected patients. Methods Since 2007, most patients evaluated for SLS at our institutions have undergone standardized respiratory testing including esophageal manometry. We analyzed these studies to define the physiological abnormalities driving respiratory restriction. Chest computed tomography data were post-processed to quantify lung volume and parenchymal density. Results Six cases met criteria for SLS. All presented with dyspnea as well as pleurisy and/or transient pleural effusions. Chest imaging results were free of parenchymal disease and corrected diffusing capacities were normal. Total lung capacities were 39%–50% of predicted. Maximal inspira tory pressures were impaired at high lung volumes, but not low lung volumes, in 5 patients. Lung compliance was strikingly reduced in all patients, accompanied by increased parenchymal density. Conclusion Patients with SLS exhibited symptomatic and/or radiographic pleuritis associated with 2 characteristic physiological abnormalities: (1) impaired respiratory force at high but not low lung volumes; and (2) markedly decreased pulmonary compliance in the absence of identifiable interstitial lung disease. These findings suggest a model in which pleural inflammation chronically impairs deep inspiration, for example through neural reflexes, leading to parenchymal reorganization that impairs lung compliance, a known complication of persistently low lung volumes. Together these processes could account for the association of SLS with pleuritis as well as the gradual symptomatic and functional progression that is a hallmark of this syndrome.