Pérez-Arellano J L, Pedraz M J, Fuertes A, de la Cruz J L, González de Buitrago J M, Jiménez A
Departamento de Medicina, Facultad de Medicina, Salamanca, Spain.
Chest. 1993 Oct;104(4):1163-9. doi: 10.1378/chest.104.4.1163.
Laminin is a 900,000-dalton extracellular matrix glycoprotein involved in a variety of functions, including cellular movement, growth, and differentiation. The aim of this work was to investigate the presence and biologic significance of this substance in the bronchoalveolar lavage fluid (BALF) of diffuse interstitial lung diseases (DILD). Levels of laminin fragment P1 (LFP) were measured by radioimmunoassay in BALF and sera from controls (n = 8) and patients with several types of DILD: sarcoidosis (n = 10), neoplastic pulmonary infiltration (n = 8), pulmonary fibrosis (n = 5), and hypersensitivity pneumonitis (n = 5). Furthermore, their relation to signs of alveolitis (cellular profiles and albumin concentration in BALF) and evidence of pulmonary fibroblast activation (BALF aminoterminal propeptide of type III procollagen) was examined. Laminin fragment P1 immunoreactivity was detectable in BALF, even in the control group, but patients with all types of DILD had higher concentrations than the control subjects. The serum levels of LFP were similar in all groups studied. Neutrophil and lymphocyte proportions were significantly higher in all DILD groups than in the control group. A positive correlation was seen between lymphocyte proportion and laminin fragment P1 in BALF. Moreover, in BALF a positive correlation was found between LFP and albumin and between LFP and the aminoterminal propeptide of type III procollagen. The BALF macrophage-associated laminin fragment P1 was significantly higher in the active sarcoidosis subgroup compared with the control group. Thus, laminin is a normal constituent of the epithelial lining fluid. The increase of laminin in BALF of patients with DILD suggests that laminin may contribute to their pathogenesis.
层粘连蛋白是一种分子量为900,000道尔顿的细胞外基质糖蛋白，参与多种功能，包括细胞运动、生长和分化。这项研究的目的是调查这种物质在弥漫性间质性肺疾病（DILD）患者支气管肺泡灌洗液（BALF）中的存在情况及其生物学意义。通过放射免疫分析法测定了对照组（n = 8）以及几种类型DILD患者（结节病，n = 10；肿瘤性肺浸润，n = 8；肺纤维化，n = 5；过敏性肺炎，n = 5）的BALF和血清中层粘连蛋白片段P1（LFP）的水平。此外，还研究了它们与肺泡炎体征（BALF中的细胞成分和白蛋白浓度）以及肺成纤维细胞活化证据（BALF中III型前胶原氨基末端前肽）之间的关系。即使在对照组中，BALF中也可检测到层粘连蛋白片段P1免疫反应性，但所有类型DILD患者的浓度均高于对照组。所有研究组的血清LFP水平相似。所有DILD组的中性粒细胞和淋巴细胞比例均显著高于对照组。BALF中淋巴细胞比例与层粘连蛋白片段P1之间呈正相关。此外，在BALF中，LFP与白蛋白以及LFP与III型前胶原氨基末端前肽之间均呈正相关。与对照组相比，活动期结节病亚组BALF中巨噬细胞相关的层粘连蛋白片段P1显著升高。因此，层粘连蛋白是上皮衬液的正常成分。DILD患者BALF中层粘连蛋白的增加表明层粘连蛋白可能在其发病机制中起作用。
