Moreto Ana, Fariñas-Alvarez Concepción, Puente Maria, Ocejo-Vinyals Javier Gonzalo, Sánchez-Velasco Pablo, Horcajada Juan Pablo, Batlle Ana, Montes Carmen, Santos Francisca, Conde Eulogio, Fariñas Maria-Carmen
Infectious Diseases Unit, Hospital Universitario Marqués de Valdecilla, University of Cantabria, IFIMAV, Santander, Spain.
BMC Immunol. 2014 May 3;15:17. doi: 10.1186/1471-2172-15-17.
Serious infections are common in patients undergoing autologous stem cell transplantation (ASCT) mainly because of the effects of immunosuppression. The innate immune system plays an important role in the defense against different infections. Mannose binding lectin (MBL) is a central molecule of the innate immune system. There are several promoter polymorphisms and structural variants of the MBL2 gene that encodes for this protein. These variants produce low levels of MBL and have been associated with an increased risk for infections.
Prospective cohort study. The incidence, severity of infections and mortality in 72 consecutive patients with hematologic diseases who underwent ASCT between February 2006 and June 2008 in a tertiary referral center were analyzed according to their MBL2 genotype. INNO-LiPA MBL2 was used for MBL2 gene amplification and genotyping. Relative risks (RR) (IC95%) as measure of association were calculated. Multivariate analysis was performed using logistic regression.
A statistically significant higher number of fungal infections was found in patients with MBL2 variants causing low MBL levels (21.1%versus1.9%, p=0.016). In this MBL2 variant group infection was more frequently the cause of mortality than in the MBL2 wild-type group (p=0.05). Although not statistically significant, there was a higher incidence of major infections in the MBL2 variant group as well as a higher number of infections caused by gram-positive bacteria.
Low-producer MBL2 genotypes were associated with an increased number of fungal infections in ASCT patients, which would suggest that MBL has a protective role against such infections. ASCT patients with MBL2 variant genotypes are more likely to die as a result of an infection.
严重感染在接受自体干细胞移植（ASCT）的患者中很常见，主要是由于免疫抑制的影响。固有免疫系统在抵御不同感染中起重要作用。甘露糖结合凝集素（MBL）是固有免疫系统的核心分子。编码该蛋白的MBL2基因存在几种启动子多态性和结构变异。这些变异导致MBL水平降低，并与感染风险增加有关。
前瞻性队列研究。对2006年2月至2008年6月在一家三级转诊中心接受ASCT的72例血液系统疾病患者，根据其MBL2基因型分析感染的发生率、严重程度和死亡率。使用INNO-LiPA MBL2进行MBL2基因扩增和基因分型。计算作为关联度量的相对风险（RR）（IC95%）。使用逻辑回归进行多变量分析。
在MBL2变异导致MBL水平低的患者中，发现真菌感染的数量在统计学上显著更高（21.1%对1.9%，p = 0.016）。在这个MBL2变异组中，感染比MBL2野生型组更常成为死亡原因（p = 0.05）。虽然无统计学意义，但MBL2变异组中主要感染的发生率更高，革兰氏阳性菌引起的感染数量也更多。
低产生型MBL2基因型与ASCT患者真菌感染数量增加有关，这表明MBL对这类感染有保护作用。具有MBL2变异基因型的ASCT患者因感染而死亡的可能性更大。
