Occupational Exposures in Patients with Systemic Sclerosis Associated with Increased Frequency of Interstitial Lung Disease and Primary Pulmonary Hypertension

Brandi E. Stevens^1,2, Mary Lucas³, Thomas A. Medsger Jr.⁴ and Robyn T. Domsic⁵, ¹Division of Rheumatology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, ²Medicine-Rheumatology, University of Pittsburgh, Pittsburgh, PA, ³Division of Rheumatology, University of Pittsburgh, Pittsburgh, PA, ⁴Department of Medicine/Rheumatology, University of Pittsburgh, Pittsburgh, PA, ⁵Medicine - Rheumatology, University of Pittsburgh, Pittsburgh, PA

Meeting: 2015 ACR/ARHP Annual Meeting

Date of first publication: September 29, 2015

Keywords: Environmental factors, interstitial lung disease and systemic sclerosis

Session Information

Date: Sunday, November 8, 2015

Title: Systemic Sclerosis, Fibrosing Syndromes and Raynaud's - Clinical Aspects and Therapeutics Poster I

Session Type: ACR Poster Session A

Session Time: 9:00AM-11:00AM

Background/Purpose:
Systemic sclerosis (SSc) has been linked with environmental and occupational
exposures. Silica and solvent exposure have the strongest known correlation
with SSc. Other agents, notably aerosolized particles, may have a potential
role in pathogenesis. To date, there has been limited information on how these
exposures relate to disease phenotype. The objective of this study was to
evaluate associations between occupational exposures and SSc phenotypes.

Methods: We used a large,
prospectively enrolled, single-center SSc cohort for analysis. At the first
visit, self-reported occupational exposure data is routinely collected. We
reviewed this occupational exposure data on all patients seen between January
1, 2000 and December 31, 2014. Exposure was categorized as: none, solvent,
silica/dust, other exposure (examples include fumes, aerosols), or ≥ 2
categories. We evaluated associations with disease phenotypes including
cutaneous subtype (diffuse vs. limited), serum autoantibody (anti-Scl70,
anti-RNA polymerase 3, anti-centromere and other) profile, and pulmonary involvement.
Pulmonary arterial hypertension (PAH) was defined as a mean pulmonary artery
pressure (PAP) > 25 mmHg on right heart catheterization or transthoracic
echocardiogram with PAP > 45mmHg and PAH diagnosed by a cardiologist.
Interstitial lung disease (ILD) required the presence of radiographic fibrosis.
Chi-square analysis was used to compare groups by exposure status.

Results: The total cohort (n=746)
was 78% female, 99% Caucasian and average age was 54 years. Of the 746 patients,
135 reported an occupational exposure. There were no differences between the exposed
and unexposed groups in age or race, although there were more males compared to
females in the exposed group (57% vs 14%, p <0.001). There was no
difference in exposure between cutaneous subtype or serum autoantibodies. ILD
was more frequent in the exposed (51%) vs. unexposed (37%) group (p=0.004).
Subanalysis of the exposed groups found individuals with dust/silica exposure
have a significantly higher rate of ILD than unexposed individuals (p=0.007).
There was no difference between the exposed and unexposed group in PAH prevalence
(p=0.29). However among the exposed group, those with “other” had a
markedly higher rate of PAH at 32% (p=0.01).

Table 1: Prevalence of PAH and ILD by Occupational Exposure Group
	No Exposure n=611	Solvent n=47	Silica/Dust n=46	Other Exposure n=31	≥ 2 Exposures n=11
Pulmonary arterial hypertension	64 (10.5%)	4(8.5%)	4 (8.7%)	10 (32.3%)	1 (9.1%)
Interstitial lung disease	228 (37.3%)	22 (46.8%)	27 (58.7%)	13 (41.9%)	7 (63.6%)

Conclusion: Males had
higher rates of occupational exposure. There was no relationship between
exposure and cutaneous or autoantibody subtype. Silica/dust exposure was
significantly associated with an increased frequency of ILD, whereas an
increased frequency of PAH was seen in those who reported an occupational
exposure that was not solvent or silica. These descriptive findings suggest
that further investigation into occupational exposures and relationship to
SSc-ILD and SSc-PAH is warranted.

Disclosure: B. E. Stevens, None; M. Lucas, None; T. A. Medsger Jr., None; R. T. Domsic, Biogen-Idec, 5,Bayer, 5.

To cite this abstract in AMA style:

Stevens BE, Lucas M, Medsger TA Jr., Domsic RT. Occupational Exposures in Patients with Systemic Sclerosis Associated with Increased Frequency of Interstitial Lung Disease and Primary Pulmonary Hypertension [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/occupational-exposures-in-patients-with-systemic-sclerosis-associated-with-increased-frequency-of-interstitial-lung-disease-and-primary-pulmonary-hypertension/. Accessed .

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