Background: The association of systemic sclerosis (SSc) with the exposure
to environmental agents is supported by a number of case reports and some
case-control studies. No conclusive results have been reported, but there are
some evidences that exposure to vinyl-chloride-polymers (PVC), silica dust
or organic solvents such as benzene (B) and xylene (X) may be implicated.
Furthermore a higher prevalence of scleroderma in boroughs in close proximity
to a major airport, has been reported, but few data on air pollution exposure and
risk of systemic sclerosis are available. Recently, particulate air pollution has
been consistently linked to increased risk of arterial cardiovascular disease.
Objectives: We studied relationships between outdoor concentration of B and
particulate with clinical manifestations of SSc based, for the exposure, on the
urban residence of patients.
Methods: Before patient administration, the questionnaire was validated by
Delphi technique (4 rheumatologists, 4 statisticians and 2 common people).
A cohort study of 88 SSc patients, filled the validated self administered
questionnaire (analyzing drug, work and environmental exposure) to
investigate potential risk exposure before and after the onset of the disease.
The average mean concentrations of B (11 monitoring sites) and environmental
particulate matter with aerodynamic diameter ≤ 10 μm(PM10) (14 sites) were
computed using data from monitors located throughout the Lazio region, in
Italy. In a sample of 33 patients we performed correlations between the concentrations
of PM10 and B with the demographic and clinical characteristics,
going back to a prior exposure of 2 years before the onset of Raynaud’s phenomenon
Results: The questionnaire resulted in an agreement of the overall experts
of about 94% (according to11/190 disagreement for comprehension, only
few lexical modifications were done to improve the questionnaire after
the consensus between the experts), with an Inter-observer agreement
(measured throughout K Cohen test) of 0.8019(p <0.01) showing a very good
concordance. The mean disease duration from the RP onset was 13.0±9.4
years and the mean age was 55.0±12.9 years. 92.5% of patients were female.
No correlations were found between different clinical disease characteristics
and drug assumption and work exposure.
Considering patients that lived in Lazio, SSc patients with diffuse skin disease
were exposed 2 years, before the onset of RP, to a higher concentrations
of benzene (8.5±1.5µg/m3
) with respect to patients with limited skin disease
), which was statistically significant of p=0.02. Furthermore
the concentrations of benzene correlated directly with the skin score (R=0.3,
p≤0.05) and inversely with DLCO (R=-0.36,p≤0.05). SSc patients with ulcers
were exposed 2 years before the onset of RP to higher concentrations of B
), than the patients without ulcers (4.9±2.3µg/m3
), but the difference
did not reach statistical significance.
Conclusions: This study, on the role of environmental agents in the
manifestations of SSc, suggests an increased exposure to benzene in the
development of a diffuse skin disease and a possible predisposing effect on
the occurrence of ulcers.
Disclosure of Interest: None Declared
- ENVIRONMENTAL POLLUTION
- SYSTEMIC SCLEROSIS