Occult alveolar haemorrhage in pulmonary veno-occlusive disease

Abstract

Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary arterial hypertension that affects predominantly post-capillary pulmonary vessels. A major concern with PVOD is the poor response to available therapies and the risk of pulmonary oedema with continuous intravenous epoprostenol.The present authors hypothesised that alveolar haemorrhage may be a characteristic feature of pulmonary veno-occlusive disease, as compared with other forms of pulmonary arterial hypertension that predominantly involve pre-capillary pulmonary arteries.This paper reports a series of 19 patients with either PVOD (n58) or idiopathic pulmonary arterial hypertension (IPAH; n511) who underwent bronchoalveolar lavage. Cytological analyses were performed and differential counts were made on Perls-stained preparations. The Golde score was used to assess alveolar haemorrhage. As compared with IPAH, PVOD was characterised by a higher percentage of haemosiderin-laden macrophages (40¡37 versus 3¡6%), resulting in elevated Golde scores (81¡88 versus 4¡10).It was concluded that occult alveolar haemorrhage is a common feature of pulmonary venoocclusive disease. Detecting occult alveolar haemorrhage may be of interest in the diagnostic approach of pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease: advances in clinical management and treatments

“…Pleural effusions have been suggested to be more frequent in PVOD, however, the studies focused on radiography with high-resolution computed tomography (HRCT) of the chest show a similar proportion of pleural effusions in both diseases [8,10,48,49]. Hemoptysis has been described in PVOD; however, in our recent study, hemoptysis was reported infrequently and equally in both idiopathic PAH and PVOD, confirming that alveolar hemorrhage in PVOD is generally occult [8,50]. Clubbing and Raynauld's phenomenon have been reported as clinical signs in PVOD but this was not reproduced in our recent series, as these signs remain rare and can also occur in idiopathic PAH [8].…”

“…Moreover, post-capillary obstruction may frequently lead to capillary angiectasia and even capillary angioproliferation; in PVOD cases, doubling and trebling of the alveolar septal capillary layers may be focally present. Lately, this histological peculiarity has raised questions concerning a possible overlap between PVOD and cases of PCH, a disease classically characterized by an aggressive patch-like Occult pulmonary hemorrhage regularly occurs in patients displaying PVOD contrarily to idiopathic PAH where alveolar hemorrhage is classically absent [50]. This is possibly due to the post-capillary bloc, and is of particular diagnostic interest, as broncho alveolar lavage (BAL) can reveal the presence of occult hemorrhage.…”

“…PVOD patients usually had a very low DL CO and in this series, half of the histologically confirmed PVOD patients had a mean DL CO of 52 ± 19% as compared with 71 ± 15% in idiopathic PAH patients [8]. In PVOD patients, alveolar hemorrhages occur quite often [50] so the DL CO should be increased in these patients.…”

“…This assessment tool for the cytologist/pathologist takes the number of intra-alveolar siderin-laden macrophages but also the degree of their staining (Perls-Prussian blue or iron staining) into consideration. A coefficient from 1 to 4 is accorded to different staining intensities, allowing a qualitative assessment during the cytological cell count: a Golde Score above 100 is considered as occult alveolar hemorrhage and may suggest PVOD in the setting of pulmonary hypertension [50]. Interestingly, venous lesions and post-capillary obstruction in PVOD are commonly associated with capillary remodeling, including angiectasia and even capillary angioproliferation (Figure 1).…”

“…Case reports [56] and case series [8,10,50] demonstrated that PCWP is usually normal (<15 mmHg) in PVOD patients. The difference between PVOD and idiopathic PAH is at the level of obstruction to blood flow, noted in pre-capillary vessels in PAH and in capillary as well as post-capillary vessels in PVOD.…”