Ten Klooster L, van Moorsel C H M, Kwakkel-van Erp J M, van Velzen-Blad H, Grutters J C
Centre of Interstitial Lung Diseases, Department of Pulmonology, St Antonius Hospital, Nieuwegein.
Division of Heart and Lungs, Department of Respiratory Medicine, University Medical Center Utrecht, Utrecht.
Clin Exp Immunol. 2015 Aug;181(2):357-61. doi: 10.1111/cei.12636. Epub 2015 Jun 8.
Immunoglobulin (Ig)A is an important immunoglobulin in mucosal immunity and protects the lungs against invading pathogens. The production of IgA is regulated by transforming growth factor (TGF)-β, a versatile cytokine and key player in the pathogenesis of pulmonary fibrosis. TGF-β is up-regulated in patients with idiopathic pulmonary fibrosis (IPF), but difficult to use as a biomarker. The aim of this study was to evaluate the prognostic value of IgA in serum in patients with IPF. We examined IgA levels at time of diagnosis in 86 patients diagnosed with IPF. Mean serum IgA level in IPF is 3·22 g/l and regression analyses showed a significant association with mortality (hazard ratio = 1·445, P = 0·002). A significantly worse survival was found in patients with IgA serum levels > 2·85 g/l compared to patients with lower IgA serum levels (P = 0·003). These findings were confirmed in a duplication cohort. In conclusion, the level of IgA in blood is a promising prognostic marker in IPF and can be implemented easily in the hospital setting. Future studies are warranted to investigate if repeated measurements of serum IgA can further improve the performance of serum IgA as a prognostic marker.
免疫球蛋白（Ig）A是黏膜免疫中的一种重要免疫球蛋白，可保护肺部免受病原体侵袭。IgA的产生受转化生长因子（TGF）-β调节，TGF-β是一种多功能细胞因子，也是肺纤维化发病机制中的关键因素。TGF-β在特发性肺纤维化（IPF）患者中上调，但难以用作生物标志物。本研究的目的是评估血清IgA在IPF患者中的预后价值。我们检测了86例确诊为IPF患者诊断时的IgA水平。IPF患者的平均血清IgA水平为3.22 g/l，回归分析显示其与死亡率显著相关（风险比=1.445，P=0.002）。与血清IgA水平较低的患者相比，血清IgA水平>2.85 g/l的患者生存率明显更差（P=0.003）。这些发现在一个重复队列中得到了证实。总之，血液中IgA水平是IPF中有前景的预后标志物，且可在医院环境中轻松应用。有必要开展进一步研究，以探讨血清IgA的重复检测是否能进一步提高其作为预后标志物的性能。
