Kinsella M, Müller N, Vedal S, Staples C, Abboud R T, Chan-Yeung M
Department of Medicine, University of British Columbia, Vancouver General Hospital, Canada.
Am Rev Respir Dis. 1990 Jun;141(6):1497-500. doi: 10.1164/ajrccm/141.6.1497.
The presence of emphysema in silicosis is believed to be secondary to the development of progressive massive fibrosis (PMF). However, it is difficult to separate out other causative factors, particularly cigarette smoking. In order to attempt to distinguish these factors, we examined 30 patients with silicosis by means of pulmonary function testing and computed tomography (CT) scans of the chest. Eighteen of these patients were either exsmokers or current smokers, and 12 of them were nonsmokers. The CT scans were read independently by two observers on two separate occasions. Silicosis was graded on a 5-point scale from 0 to 4; emphysema was graded as a percentage of lung involved. Percent emphysema was associated with level of pulmonary function (FEV1, FVC, and DLCO) independent of its association with either cigarette smoking or silicosis grade (p less than 0.01). Silicosis grade was associated with DLCO (p less than 0.05) independent of its association with either cigarette smoking or percent emphysema, but was not associated with level of FEV1 or FVC. In the group without PMF (silicosis Grade 0, 1, or 2), smokers had worse emphysema than nonsmokers (p less than 0.01); there was no such difference among the patients with PMF (silicosis Grade 3 or 4). Only one of the nonsmoking subjects with silicosis but without PMF had any emphysema detected on CT. Our data suggest that silicosis, in the absence of PMF, does not cause significant emphysema, and that it is primarily the degree of emphysema rather than the degree of silicosis that determines the level of pulmonary function.
矽肺中肺气肿的存在被认为是继发于进行性大块纤维化（PMF）的发展。然而，很难区分出其他致病因素，尤其是吸烟。为了试图区分这些因素，我们通过肺功能测试和胸部计算机断层扫描（CT）对30例矽肺患者进行了检查。这些患者中有18例曾经吸烟或目前仍在吸烟，12例为不吸烟者。CT扫描由两名观察者在两个不同时间独立解读。矽肺按0至4的5分制分级；肺气肿按受累肺的百分比分级。肺气肿百分比与肺功能水平（FEV1、FVC和DLCO）相关，与吸烟或矽肺分级无关（p<0.01）。矽肺分级与DLCO相关（p<0.05），与吸烟或肺气肿百分比无关，但与FEV1或FVC水平无关。在没有PMF的组（矽肺0级、1级或2级）中，吸烟者的肺气肿比不吸烟者更严重（p<0.01）；在有PMF的患者（矽肺3级或4级）中没有这种差异。在没有PMF的矽肺不吸烟受试者中，只有一人在CT上检测到有肺气肿。我们的数据表明，在没有PMF的情况下，矽肺不会导致明显的肺气肿，并且主要是肺气肿的程度而非矽肺的程度决定了肺功能水平。
