Interstitial Lung Disease In Connective Tissue Disease:a Clinical Study Of394Cases

BACKGROUNDConnective tissue disease (CTDs) represents a diverse group of immune-mediate inflammatory diseases that frequent target the lung. Interstitial lung disease(ILD) is common in many of these diffuse connective tissue diseases, including Rheumatoid Arthritis(RA), Systemic Lupus Erythematosus(SLE), Sjogren’s syndrome(SS), Systemic sclerosis(SSc), Polymyositis and Dermatomyositis(PM/DM).OBJECTIVETo study the clinical manifestions and laboratory features of connective tissue disease associated interstitial lung disease.METHODSThe clinical data were collected from394inpatients with connective tissue disease treated in Provincial Hospital Affiliated to Shandong University during April2012to December2013, of which52patients associated interstitial lung disease. We compared the clinical manifestions, laboratory features, results of pulmonary function test, and radiological features. The clinical data were analysized with SPSS19.0statistical software. Data are presented as mean±standard (SD) or median (range) if continuous or as frequencies if categorical. Group data comparisons were made using T-test or Mann-Whitney U test and categorical data comparisons were made using Chi-square test or Fisher exact test. A p value less than0.05was considered to indicate statistical significance.RRSULTSThe incidence of ILD in the160patients with RA was11.25%. Raynaud’s phenomenon and pulmonary hypertension are more common in RA-ILD patients than those without ILD. Compared with patients without ILD, RA-ILD patients exhibit a disproportionate rise in their RF-IgA leve. There are no significant differences of gender, smoking, age, duration, ESR, CRP, ANA, RF, CCP, RF-IgG, RF-IgM, GPI, RA33and CMV between the two groups of RA with or without ILD.The incidence of ILD in the157patients with SLE was8.28%. Morbidity of Raynaud’s phenomenon or incidence of pulonnary hypertension was higher in patients with ILD. The SLE-ILD patients always has a longer duration than those patients without ILD, but there are no significant differences of age, gender, ESR, CRP, ANA, Complements, dsDNA, sm, AnuA, rRNP and AHA between the two groups of SLE with or without ILD.In the study, the incidence of ILD in SS, PM/DM, and SSc patients were17.07%,35.00%and43.75%. it showed no differences in clinical manifestations or laboratory results in SS. PM/DM, or SSc patients with or without ILD.A total of52incidennt ILD patients were included in the study. Sex ratio (F/M) was46/6, and the age rang was (17-76) years. The disease duration was from1month to30years. All of the52CTD-ILD patients had HRCT findings. Of which the most common findings was interlobular septal thickening (43cases), others such as ground glass poacities in31cases, patchy shadow in31cases, reticulation in32cases,4cases of pleural effusion, and pericardial effusion in5cases.30cases of the52CTD-ILD patients had pulmonary function tests, and all showed diffuse dysfunction. It also shows that normal ventilatory function in2cases, mixed ventilatory dysfunction in7cases, restrictive ventilatory dysfunction in18cases, obstructive ventilatory dysfunction in3cases and small airway dysfunction in4cases。CONCLUSIONDiffuse interstitial lung diseases are a common manifestation of connective tissue diseases, and the overall CTD-ILD incidence estimated13.20%in this study. The frequency of ILD, thoracic manifestations and tapical interstitial imaging findings can be different in different connective tissue disease, and the incidence rate in systemic sclerosis is43.75%,which is higher than any other CTDs, such as polymyositis, dermatomyositis, Sjogren’s syndrome, and so on. Clinical manifestations, Raynaud’s phenomenon were higher in RA-ILD group and SLE-ILD group than that of the control group.ILD may presenting as a forme frusta of systemic disease, in some cases preceding extra pulmonary manifestation of connective tissue disease by years, sometimes making the diagnose og CTD-related ILD difficult. Interstitial lung disease can be a particularly striking manifestation of systemic disease, and the resulting dyspnea can be very serious. The most common HRCT findings of CTD-ILD was interlobular septal thickening, whereas pleural effusion is less common in CTDs. Lung function findings vary from isolated decrease in DLCO, restrictive pattern, small airway disease to an obstructive.