Modern age pathology of pulmonary arterial hypertension.
BACKGROUND
The impact of modern treatments of pulmonary arterial hypertension (PAH) on pulmonary vascular pathology remains unknown.


OBJECTIVE
To assess the spectrum of pulmonary vascular remodeling in the modern era of PAH medication.


METHODS
Assessment of pulmonary vascular remodeling and inflammation in 62 PAH and 28 control explanted lungs systematically sampled.


RESULTS
Intima and intima plus media fractional thicknesses of pulmonary arteries were increased in the PAH group versus the control lungs and correlated with pulmonary hemodynamic measurements. Despite a high variability of morphological measurements within a given PAH lung and among all PAH lungs, distinct pathological subphenotypes were detected in cohorts of PAH lungs. These included a subset of lungs lacking intima or, most prominently, media remodeling, which had similar numbers of profiles of plexiform lesions as those in lungs with more pronounced remodeling. Marked perivascular inflammation was present in a high number of PAH lungs and correlated with intima plus media remodeling. The number of profiles of plexiform lesions was significantly lower in lungs of male patients and those never treated with prostacyclin or its analogs.


CONCLUSIONS
Our results indicate that multiple features of pulmonary vascular remodeling are present in patients treated with modern PAH therapies. Perivascular inflammation may have an important role in the processes of vascular remodeling, all of which may ultimately lead to increased pulmonary artery pressure. Moreover, our study provides a framework to interpret and design translational studies in PAH.
Institute of Pathology, Medical University of Graz, Graz, Austria.
Elvira
E
Stacher
Brian B
BB
Graham
James M
JM
Hunt
Aneta
A
Gandjeva
Steve D
SD
Groshong
Vallerie V
VV
McLaughlin
Marsha
M
Jessup
William E
WE
Grizzle
Michaela A
MA
Aldred
Carlyne D
CD
Cool
Rubin M
RM
Tuder
D000328:Adult; D000368:Aged; D056151:Airway Remodeling; D000704:Analysis of Variance; D000959:Antihypertensive Agents / Q000627:therapeutic use; D015331:Cohort Studies; D011464:Epoprostenol / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D007249:Inflammation / Q000150:complications / Q000473:pathology; D008168:Lung / Q000098:blood supply / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology; D011651:Pulmonary Artery / Q000473:pathology*; D017678:Sex Distribution
D000959:Antihypertensive Agents; D011464:Epoprostenol