RESUMO
OBJECTIVES: Interstitial lung disease (ILD) is highly prevalent in patients with mixed connective tissue disease (MCTD). However, little is known about the long-term progression of ILD in MCTD. The aims of this study were to describe pulmonary function test (PFT) and high-resolution computed tomography (HRCT) results in long-term MCTD patients, to measure changes in PFT and HRCT results over a 10-year period, and to ascertain correlations in functional and imaging data. METHODS: In this retrospective cohort study, comparison between baseline and follow-up PFT and HRCT data was performed for 39 unselected consecutive MCTD patients. RESULTS: At baseline, 51% of the patients had abnormal PFTs. Forced vital capacity (FVC) was slightly reduced at baseline (77% of predicted), but remained stable after 10 years. A relative decrease of 15% in the diffusion capacity for carbon monoxide (DLCO) was detected (from 84% to 71% of predicted, p<0.001). The median lower lobes ILD-HRCT score progressed from 7.5% at baseline to 11.2% at follow-up (p=0.02), and findings of traction bronchiolectasis and honeycombing increased (p<0.05). A moderate negative correlation was observed between functional parameters and quantification of image findings. CONCLUSIONS: Functional and radiologic alterations suggestive of ILD in long-term MCTD patients are prevalent, mild, and progressed slightly over time. The most sensitive parameters for detecting subtle progression of ILD in MCTD patients are trends in DLCO, quantification of lower-lobes disease by HRCT (lower-lobes %ILD-HRCT score), and qualitative analysis of HRCT imaging.
Assuntos
Doenças Pulmonares Intersticiais/etiologia , Pulmão , Doença Mista do Tecido Conjuntivo/complicações , Adulto , Progressão da Doença , Feminino , Humanos , Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doença Mista do Tecido Conjuntivo/diagnóstico , Capacidade de Difusão Pulmonar , Testes de Função Respiratória , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Tomografia Computadorizada por Raios X , Capacidade VitalRESUMO
BACKGROUND: Antibodies directed against endothelial cell surface antigens have been described in many disorders and have been associated with disease activity. Since the most prominent histopathologic feature in mixed connective tissue disease (MCTD) is the widespread and unique proliferative vascular lesion, our aim was to evaluate the frequency of anti-endothelial cell antibodies (AECA) in this condition. OBJECTIVES: To evaluate the frequency of AECA in this disease and assess its clinical and laboratory associations. METHODS: Seventy-three sera from 35 patients with MCTD (Kasukawa's criteria), collected during a 7 year period, were tested for immunoglobulins G and M (IgG and IgM) AECA by cellular ELISA, using HUVEC (human umbilical vein endothelial cells). Sera from 37 patients with systemic lupus erythematosus (SLE), 22 with systemic sclerosis (SSc) and 36 sera from normal healthy individuals were used as controls. A cellular ELISA using HeLa cells was also performed as a laboratory control method. RESULTS: IgG-AECA was detected in 77% of MCTD patients, 54% of SLE patients, 36% of SSc patients and 6% of normal controls. In MCTD, IgG-AECA was associated with vasculitic manifestations, disease activity and lymphopenia, and was also a predictor of constant disease activity. Immunosuppressive drugs were shown to reduce IgG-AECA titers. Since antibodies directed to HeLa cell surface were negative, AECA was apparently unrelated to common epitopes present on epithelial cell lines. CONCLUSIONS: AECA are present in a large proportion of patients with MCTD and these antibodies decrease after immunosuppressive treatment.