Asbestos-related pleural and lung fibrosis in patients with retroperitoneal fibrosis
Toomas Uibu
2
Ritva Jrvenp
2
Jari Hakomki
2
Anssi Auvinen
1
Eero Honkanen
0
Kaj Metsrinne
5
Pekka Roto
4
Heikki Saha
2
Jukka Uitti
3
Panu Oksa
3
0
Department of Medicine, Division of Nephrology, Helsinki University Central Hospital
,
Helsinki
,
Finland
1
Tampere School of Public Health, University of Tampere
,
Tampere
,
Finland
2
Departments of Respiratory Medicine, Radiology, and Internal Medicine, Tampere University Hospital
,
Tampere
,
Finland
3
Clinic of Occupational Medicine, Tampere University Hospital and Finnish Institute of Occupational Health Tampere
,
Finland
4
Finnish Health Centers LTD
,
Tampere
,
Finland
5
Department of Internal Medicine, Turku University Hospital
,
Turku
,
Finland
Background: Retroperitoneal fibrosis (RPF) is a rare fibroinflammatory disease that leads to hydronephrosis and renal failure. In a case-control study, we have recently shown that asbestos exposure was the most important risk factor for RPF in the Finnish population. The aim of this study was to evaluate the relation of asbestos exposure to radiologically confirmed lung and pleural fibrosis among patients with RPF. Methods: Chest high-resolution computed tomography (HRCT) was performed on 16 unexposed and 22 asbestos-exposed RPF patients and 18 asbestos-exposed controls. Parietal pleural plaques (PPP), diffuse pleural thickening (DPT) and parenchymal fibrosis were scored separately. Results: Most of the asbestos-exposed RPF patients and half of the asbestos-exposed controls had bilateral PPP, but only a few had lung fibrosis. Minor bilateral plaques were detected in two of the unexposed RPF patients, and none had lung fibrosis. DPT was most frequent and thickest in the asbestos-exposed RPF-patients. In three asbestos-exposed patients with RPF we observed exceptionally large pleural masses that were located anteriorly in the pleural space and continued into the anterior mediastinum. Asbestos exposure was associated with DPT in comparisons between RPF patients and controls (case-control analysis) as well as among RPF patients (case-case analysis). Conclusion: The most distinctive feature of the asbestos-exposed RPF patients was a thick DPT. An asbestos-related pleural finding was common in the asbestos-exposed RPF patients, but only a few of these patients had parenchymal lung fibrosis. RPF without asbestos exposure was not associated with pleural or lung fibrosis. The findings suggest a shared etiology for RPF and pleural fibrosis and furthermore possibly a similar pathogenetic mechanisms.
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Background
Retroperitoneal fibrosis (RPF), or Ormond's disease, is a
rare condition with fibrosis covering the abdominal aorta
and the ureters. The etiology of RPF is generally unknown.
It has been proposed that approximately one-third of RPF
cases develop secondarily to aortic aneurysm, abdominal
infections or surgery and as a side effect of several drugs,
especially methysergide and other ergot derivates [1-3].
Asbestos is known to cause diffuse pleural thickening
(DPT) and parietal pleural plaques [4]. High-level
asbestos exposure may lead to the development of clinically
detectable lung fibrosis (asbestosis) [5]. We have recently
shown that asbestos exposure is one of the most
important single risk factors for RPF, accounting for
approximately 20% of all RPF cases in the Finnish population
[6,7]. The aim of this study was to determine whether RPF
patients have pleural or lung fibrosis and to assess the
relations between asbestos exposure and intrathoracic
fibrotic changes in RPF patients. Furthermore we
evaluated the susceptibility for pleural and lung fibrosis among
asbestos-exposed RPF patients and asbestos-exposed
controls.
Subjects and methods
Study population
This material was part of our case-control study including
43 persons with RPF and 179 randomly assigned controls
matched for year of birth, gender and central hospital
district in Finland [6]. The diagnosis of RPF required the
presence of the typical clinical conditionfibrosing mass
covering the abdominal aorta and other retroperitoneal
structuresand either histological confirmation (35 of 43
persons) or a follow-up of at least 1 year in order to rule
out retroperitoneal malignancies (8 of 43 persons).
All of the participants were interviewed for medical
history and asbestos exposure. The cumulative exposure to
asbestos dust was estimated using fiber-years (40-hour
shift per week at an average dust level of 1 fiber/ml for 1
year) and graded as follows: no significant asbestos
exposure; slight exposure (asbestos exposure <10 fiber-years)
and moderate-to-high exposure (asbestos exposure 10
fiber-years). Exposure was assessed by an occupational
health physician with special expertise in the evaluation
of asbestos exposure, the physician was blinded in terms
of the case-control status of the participants. The details of
the data collection have been given in our previous report
[6].
We asked all of the unexposed and exposed patients with
RPF and the con (...truncated)