TY - JOUR 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 DO - 10.3899/jrheum.121048 SP - jrheum.121048 AU - Lauren A. Henderson AU - Stephen H. Loring AU - Ritu R. Gill AU - Katherine P. Liao AU - Rumey Ishizawar AU - Susan Kim AU - Robin Perlmutter-Goldenson AU - Deborah Rothman AU - Mary Beth F. Son AU - Matthew L. Stoll AU - Lawrence S. Zemel AU - Christy Sandborg AU - Paul F. Dellaripa AU - Peter A. Nigrovic Y1 - 2013/02/01 UR - http://www.jrheum.org/content/early/2013/01/27/jrheum.121048.abstract N2 - 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. ER -