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Background: Pulmonary venoocclusive disease (PVOD) is an uncommon form of pulmonary hypertension (PH) predominantly characterized by pulmonary vein and capillary involvement. An association between chemotherapy, in particular mitomycin C (MMC), and PVOD has been reported., Research Question: What are the characteristics of MMC-induced PVOD, and what is the prognosis for patients with MMC-induced PVOD?, Study Design and Methods: We report the clinical, functional, radiologic, and hemodynamic characteristics at diagnosis and outcomes of patients with PVOD from the French PH Registry after exposure to MMC. The results are expressed as the median (minimum-maximum)., Results: From June 2011 to December 2018, 17 incident cases of MMC-induced PVOD were identified. At diagnosis, these patients had severe clinical and functional impairment, with 12 patients having a New York Heart Association (NYHA) functional class of III or IV and a 6-min walk distance of 220 (0-465) m. Right heart catheterization confirmed severe precapillary PH with a mean pulmonary artery pressure of 38 (30-52) mm Hg, a cardiac index of 2.2 (1.5-4) L/(min × m 2 ), and pulmonary vascular resistance of 8.3 (5.1-14.5) Wood units. The diffusing capacity of the lungs for carbon monoxide was markedly decreased at 31% (20%-51%) of the theoretical values associated with severe hypoxemia. MMC was withdrawn for all patients, and 14 patients received specific pulmonary arterial hypertension (PAH) therapies. Among these patients, mild but statistically insignificant improvements were observed in NYHA functional class (P = .10), 6-min walk distance (P = .09), and pulmonary vascular resistance (-4.7 Wood units; P = .052) at reassessment (median delay of 4.8 months). Three patients experienced pulmonary edema requiring the cessation or reduction of PAH treatment. The median overall survival was 20 months, and the 6-, 12-, and 24-month survival rates were 76%, 58%, and 18%, respectively., Interpretation: PVOD after MMC treatment is a rare but life-threatening complication associated with a poor prognosis despite MMC withdrawal and PAH-specific therapy., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Trichloroethylene (TCE) is a chlorinated solvent that has been used widely around the world in the twentieth century for metal degreasing and dry cleaning. Although TCE displays general toxicity and is classified as a human carcinogen, the association between TCE exposure and respiratory disorders are conflicting. In this review we aimed to systematically evaluate the current evidence for the respiratory effects of TCE exposure and the implications for the practicing clinician. There is limited evidence of an increased risk of lung cancer associated with TCE exposure based on animal and human data. However, the effect of other chlorinated solvents and mixed solvent exposure should be further investigated. Limited data are available to support an association between TCE exposure and respiratory tract disorders such as asthma, chronic bronchitis, or rhinitis. The most consistent data is the association of TCE with autoimmune and vascular diseases such as systemic sclerosis and pulmonary veno-occlusive disease. Although recent data are reassuring regarding the absence of an increased lung cancer risk with TCE exposure, clinicians should be aware of other potential respiratory effects of TCE. In particular, occupational exposure to TCE has been linked to less common conditions such as systemic sclerosis and pulmonary veno-occlusive disease., (Copyright © 2017. Published by Elsevier Ltd.)

Tuberculosis (TB) remains a global health concern. Trehalose 6'6-dimycolate (TDM) activates innate inflammation and likely also stimulates chronic inflammation observed during disease progression. Noninfectious models using purified TDM oil/water emulsions elicit pathologic findings observed in patients with TB. We introduce a new TDM model that promotes inflammatory lung pathologic findings and vascular occlusion and hemorrhage. C57BL/6 and BALB/c mice were injected with 10 μg of i.p. TDM in light mineral oil (TDM-IP). At day 7, another injection of 10 μg of i.v. TDM in oil/water emulsion was given (TDM-IV). The i.p./i.v. TDM (TDM-IVIP) group was compared with mice injected once with i.v. or i.p. TDM. The responses to TDM-IP, TDM-IV, or TDM-IPIV were consistent between mouse strains. Mice that received TDM-IV and TDM-IPIV had inflammatory pathologic findings with increases in inflammatory and T-cell cytokines, and the TDM-IPIV group had further enhancement of IL-10 and granulocyte-macrophage colony-stimulating factor. The TDM-IPIV group had increased CD4(+) T cells in lung tissue, significantly increased coagulation, decreased clot formation time, and increased maximum clot firmness. Masson's trichrome staining revealed increased deposition of collagen in the occluded vasculature. TDM-IPIV promotes a hypercoagulopathy state, independent of inflammation. This new model argues that TDM is sufficient to generate the hypercoagulopathy observed in patients with TB., (Copyright © 2016. Published by Elsevier Inc.)

Pulmonary venoocclusive disease (PVOD) is a rare cause of pulmonary hypertension characterized by a progressive clinical course and poor outcomes if not treated by early lung transplantation. The pathogenesis of PVOD remains poorly understood. We report PVOD that developed in 2 young women soon after the initiation of oral contraceptives (OCs). The first patient is a 14-year-old girl, with no medical history, who started taking an OC 3 weeks before the onset of symptoms. The second patient is an 18-year-old girl, diagnosed 2 years previously with systemic lupus erythematosus and lupus anticoagulant, who started taking an OC 4 months before the onset of symptoms. Both patients required lung transplantation. Radiographic and histopathologic findings in both patients showed features of PVOD. Only 1 prior patient with PVOD and a handful of unclassified patients with pulmonary hypertension in association with OCs have been documented. The importance of PVOD as the basis of pulmonary hypertension in patients with connective tissue disease has been recently proposed, as well as the role of thrombogenesis, in the development of PVOD. The temporal sequence in these 2 patients suggests the thrombogenic action of OCs may contribute to the development of PVOD, with or without underlying connective tissue disease., (Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Pulmonary thrombosis in the course of shock remains life-threatening, despite advances in diagnosis, prophylaxis and therapy of the disease. Tumour necrosis factor-alpha (TNF-alpha) is an important mediator of shock. The aim of this study was to analyze the morphological changes in the pulmonary capillary bed in rats after intraperitoneal administration of multiple doses of TNF-alpha (10 microg TNF-alpha/24 h for 5 days; biological activity of 2-4x10(7)U/mg of protein). Morphological investigations were undertaken by light and transmission electron microscopy with emphasis on pulmonary thrombopoiesis. The study confirmed that the lungs may be an important site of extramedullary thrombopoiesis in the course of shock. The observations also suggested that megakaryocytes shed large fragments of cytoplasm within the pulmonary capillary bed and that megakaryocytes with copious cytoplasm occlude pulmonary vessels., (Copyright 1999 W.B. Saunders Company Ltd.)

We report three cases of pulmonary veno-occlusive disease which developed following treatment for malignant neoplasms. Two patients received single agent BCNU chemotherapy for malignant gliomas. The third patient underwent combination radiation and chemotherapy for Hodgkin's disease. Isolated case reports of pulmonary veno-occlusive disease following therapy for malignant disease are reviewed and clinical features summarized. Pulmonary veno-occlusive disease in this setting is thought to be rare. However, the diagnosis is rarely suspected clinically and is difficult to diagnose pathologically. Therefore, the true incidence of this complication is unknown and may be higher than believed. It is important that both clinician and pathologist be aware of this entity; otherwise, elastic tissue stains may not be performed and the diagnosis missed.