Jornal Brasileiro de Pneumologia (Dec 2010)
Trombose em artérias pulmonares pequenas e médias em granulomatose de Wegener: um estudo com microscopia confocal por varredura a laser Thrombosis in small and medium-sized pulmonary arteries in Wegener's granulomatosis: a confocal laser scanning microscopy study
Abstract
OBJETIVO: A granulomatose de Wegener (GW) pode causar dano nas células endoteliais e fenômenos tromboembólicos. Entretanto, poucos estudos analisaram a microcirculação pulmonar - artérias pulmonares de pequeno/médio calibre (APPMC) - em pacientes com GW. O objetivo deste estudo foi quantificar trombos de fibrina em amostras de APPMC de pacientes com GW. MÉTODOS: Analisamos 24 APPMC de seis pacientes com GW e 16 APPMC de quatro pacientes controles sem WG. Utilizamos CD34 para a marcação do endotélio em todas as amostras e microscopia confocal a laser para detectar trombos de fibrina intravasculares. Calculamos a área total do vaso, a área livre do lúmen e a área trombótica. RESULTADOS: A média da área total do vaso foi similar no grupo GW e no grupo controle (32.604 µm² vs. 32.970 µm², p = 0,8793). Trombos foram identificados em 22 das 24 APPMC (91,67%) no grupo GW, e em nenhuma do grupo controle (p OBJECTIVE: Wegener's granulomatosis (WG) can cause endothelial cell damage and thromboembolic events. Nevertheless, there have been few studies on the pulmonary microcirculation-small and medium-sized pulmonary arteries (SMSPA)-in patients with WG. The objective of this study was to quantify fibrin thrombi in the SMSPA of patients with WG. METHODS: We analyzed 24 SMSPA samples collected from six patients with WG and 16 SMSPA samples collected from four patients without WG. In all samples, we used the endothelial cell marker CD34 and confocal laser scanning microscopy in order to detect intravascular fibrin thrombi. We calculated the total vessel area, the free lumen area, and the thrombotic area. RESULTS: The mean total vessel area was similar in the WG and control groups (32,604 µm² vs. 32,970 µm², p = 0.8793). Thrombi were present in 22 (91.67%) of the 24 WG group samples and in none of the control group samples (p < 0.0001; OR = 297; 95% CI: 13.34-6,612). The mean thrombotic area was greater in the WG group samples than in the control group samples (10,068 µm² vs. 0.000 µm²; p < 0.0001). In contrast, the mean free lumen area was smaller in the WG group samples than in the control group samples (6,116 µm² vs. 24,707 µm²; p < 0.0001). CONCLUSIONS: Confocal laser scanning microscopy revealed a significant association between pulmonary microvascular thrombosis and WG. This suggests a possible role of microvascular thrombosis in the pathophysiology of pulmonary WG, evoking the potential benefits of anticoagulation therapy in pulmonary WG. However, further studies are needed in order to confirm our findings, and randomized clinical trials should be conducted in order to test the role of anticoagulation therapy in the treatment of patients with pulmonary WG.
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