Progress in plexiform lesion of pulmonary hypertension / 中国病理生理杂志

[ABSTRACT]Pulmonaryarterialhypertensionisdefinedasamultifactorialgroupofpulmonaryvasculardisorders characterized by a progressive increase in the pulmonary vascular resistance , resulting in right heart failure and premature death.The plexiform lesion is the hallmark of severe pulmonary arterial hypertension .This article summarized the recent progress in the plexiform lesion including its occurrence , structure, animal models and molecular mechanism , which tried to predict the tendency of plexiform lesion study .

Study on the Clonality of Endothelial Cell Proliferation in Plexiform Lesions in Patients with Pulmonary Hypertension Associated with CREST Syndrome / 결핵

BACKGROUND: The CREST syndrome is an indolent form of progressive systemic sclerosis. Although its clinical progress is indolent, pulmonary hypertension(PH) associated with CREST syndrome have grave prognosis with over 40 percent mortality rate at 2 year follow-up. But the pathogenesis of pulmonary hypertension in this disease is not known, and classified as either primary or secondary PH. Clonality of endothelial cell proliferation in plexiform lesion is a molecular marker which allows distinction between primary and secondary PH. We performed this study to know whether the PH associated with CREST syndrome is a variant of primary PH or is a secondary PH. METHODS: We assessed the X-chromosome inactivation based on the methylation pattern of the human androgen-receptor gene by PCR(HUMARA). Endothelial cells in plexiform lesions from female patients(n=3) with PH associated with CREST syndrome were microdissected from paraffin blocks. Vascular smooth muscle cells and lung parenchyma were also microdissected for clonality studies. RESULTS: The proliferating endothelial cells in 14 plexiform lesions were all polyclonal. Similarly proliferated smooth muscle cells from 5 vessels with medial hypertrophy were also polyclonal. CONCLUSION: These results suggest that the pulmonary hypertension associated with CREST syndrome has different pathogenesis from primary PH and to be classified as secondary PH.

An Autopsied Case of Primary Pulmonary Hypertension

A twenty four-year-old female patient had suffered progressive dyspnea for 6 years until death. She denied any symptoms suggestive of connective tissue disease, or deep vein thrombosis. She suffered an episode of pontine infarct in 1995. Four years after diagnosis of primary pulmonary hypertension, she died of sudden death during hospitalization. Gross features of pulmonary arteries at autopsy were as follows: left main pulmonary artery showed dilation of the lumen and thickening of the wall, and right main pulmonary artery was markedly dilated and contained fresh thrombus. Hematoxylin and eosin-stained sections of lung tissue showed plexiform lesions of pulmonary arteries, complete luminal obliteration of pulmonary arterioles and dilated lesion of pulmonary arterioles, and capillaries. This patient represents a typical case with a primary pulmonary arteriopathy with plexiform lesions with thrombotic lesion, demonstrating the importance of thrombosis in situ in the pathogenesis of primary pulmonary hypertension. To our knowledge, this is the first autopsy report on the primary pulmonary hypertension in Korea.