Clinical Peculiarities Of 12 Patients With Systemic Sclerosis Occupationally Exposed To Silica

Objective: To summarize the clinical characteristics of patients with systemic sclerosis(SSc)with occupational exposure to silica and compare them with patients without occupational exposure during the same period in terms of clinical manifestations,laboratory data,and imaging manifestations,in order to improve the understanding of the effects of occupational exposure on systemic sclerosis.Methods : Patients with SSc who were hospitalized in Affiliated Hospital of Guilin Medical University from January 2013 to January 2022 and had occupational exposure to silica were selected as the case group(silica-exposed group),and patients with SSc who were not exposed during the same period were randomly selected as the control group(non-exposed group)according to1:3.The general clinical data(such as age of onset,occupation,past medical history),clinical manifestations,disease duration,laboratory indices,pulmonary function,echocardiography,and high resolution CT(HRCT)of the chest were collected and statistically analyzed.Results: 1.12 patients with occupational exposure to silica,with a mean age of onset of 50.33±6.15 years and 8 cases of diffuse skin sclerosis type,with a more extensive skin sclerosis than the control group(p=0.049).2.Both groups had different degrees of visceral involvement,with the lung being the most common organ involved.7 patients in the exposed group had interstitial lung disease(ILD),and 4(4/7,57%)patients had interstitial lung changes exceeding20% of the whole lung,while 24 patients in the control group had ILD,and 17(17/24,71%)patients had interstitial lung changes less than 20%.The interstitial lung changes were less than 20%.3,7 patients with ILD in the exposed group had predominantly restrictive or mixed ventilation dysfunction,and the percentage of Forced expiratory volume in one second(FEV1)was lower than the expected value in the control group(p=0.003).3.Seven patients with ILD in the exposed group had predominantly restrictive or mixed ventilation dysfunction and a lower percentage of Forced expiratory volume in one second(FEV1)than the control group(p=0.003).4.Nine cases in the exposed group showed cardiac involvement,of which ECG abnormalities were predominantly bundle branch block(two cases of complete right bundle branch block and one case of left anterior descending branch block),while in the control group ECG abnormalities were predominantly ST-T segment changes(p=0.041);left ventricular ejection fraction(LVEF)was 61.33±2.49% in the exposed group,which was lower than that in the control group(p=0.036).5.Anti-nuclear antibodies were predominantly homogeneous in the exposed group,and anti-cl-70 antibodies were present in all of them.6.Correlation analysis suggested that occupational exposure to silica,age at onset <50 years,Raynaud’s phenomenon,and anti-cl-70 were not associated with interstitial lung disease,but age at onset<50 years was associated with cardiac involvement(OR=6.950,p=0.007).Conclusions: 1.Male SSc patients with occupational exposure to silica tend to exhibit diffuse skin sclerosis type.2.More prone to lung involvement,more extensive pulmonary fibrosis and poorer ventilation than unexposed SSc patients.3.The silica-exposed group was more likely to have cardiac involvement and a lower left ventricular ejection fraction.4.No significant differences in immunology and serology between the two groups.