Metzger M-L, Michelfelder I, Goldacker S, Melkaoui K, Litzman J, Guzman D, Grimbacher B, Salzer U
Centre for Chronic Immunodeficiency (CCI), University Medical Centre Freiburg, University of Freiburg, Freiburg, Germany.
Clin Exp Immunol. 2015 Feb;179(2):256-64. doi: 10.1111/cei.12459.
Common variable immunodeficiency (CVID) encompasses a heterogeneous group of antibody deficiencies characterized by susceptibility to recurrent infections and sequelae, including bronchiectasis. We investigated the relevance of the lectin complement pathway in CVID patients by analysing ficolin-2 and ficolin-3 serum levels and genotyping single nucleotide polymorphisms (SNPs) in the FCN2 and FCN3 genes. Our results show that ficolin-2 levels in CVID patients are significantly lower (P < 0.0001) than in controls. The lowest ficolin-2 levels are found in CVID patients with bronchiectasis (P = 0.0004) and autoimmunity (P = 0.04). Although serum levels of ficolin-3 were similar in CVID patients and controls, CVID patients with bronchiectasis again showed lower levels when compared to controls (P = 0.0001). Analysis of single nucleotide polymorphisms in the FCN2 gene confirmed known influences on ficolin-2 serum levels, but did not support a genetic basis for the observed ficolin-2 deficiency in CVID. We found that CVID patients with bronchiectasis have very low levels of ficolin-2. The reason for the deficiency of ficolin-2 in CVID and any possible causal relationship is currently unknown. However, as bronchiectasis is a very important factor for morbidity and mortality in CVID, ficolin-2 could also serve as biomarker for monitoring disease complications such as bronchiectasis.
普通变异型免疫缺陷（CVID）包括一组异质性抗体缺陷，其特征为易反复感染及出现后遗症，包括支气管扩张。我们通过分析纤维胶凝蛋白-2和纤维胶凝蛋白-3的血清水平以及对FCN2和FCN3基因中的单核苷酸多态性（SNP）进行基因分型，研究凝集素补体途径在CVID患者中的相关性。我们的结果显示，CVID患者的纤维胶凝蛋白-2水平显著低于对照组（P < 0.0001）。在患有支气管扩张（P = 0.0004）和自身免疫（P = 0.04）的CVID患者中，纤维胶凝蛋白-2水平最低。尽管CVID患者和对照组的纤维胶凝蛋白-3血清水平相似，但与对照组相比，患有支气管扩张的CVID患者的纤维胶凝蛋白-3水平再次降低（P = 0.0001）。对FCN2基因中的单核苷酸多态性分析证实了其对纤维胶凝蛋白-2血清水平的已知影响，但不支持在CVID中观察到的纤维胶凝蛋白-2缺乏存在遗传基础。我们发现，患有支气管扩张的CVID患者的纤维胶凝蛋白-2水平非常低。目前尚不清楚CVID中纤维胶凝蛋白-2缺乏的原因以及任何可能的因果关系。然而，由于支气管扩张是CVID发病和死亡的一个非常重要的因素，纤维胶凝蛋白-2也可作为监测支气管扩张等疾病并发症的生物标志物。
