gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie
74. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie
96. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie
51. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie

26. - 29.10.2010, Berlin

Polymorphisms in MBL2 increase susceptability for infectious complications in polytrauma patients

Meeting Abstract

  • M. Bronkhorst - Erasmus MC Rotterdam, Surgery - Traumatology, Rotterdam, Netherlands
  • E. Van Lieshout - Erasmus MC Rotterdam, Surgery - Traumatology, Rotterdam, Netherlands
  • P. Patka - Erasmus MC Rotterdam, Surgery - Traumatology, Rotterdam, Netherlands

Deutscher Kongress für Orthopädie und Unfallchirurgie. 74. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 96. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 51. Tagung des Berufsverbandes der Fachärzte für Orthopädie. Berlin, 26.-29.10.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocIN24-571

DOI: 10.3205/10dkou148, URN: urn:nbn:de:0183-10dkou1483

Published: October 21, 2010

© 2010 Bronkhorst et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: Despite innovations in systematic approaches towards treatment in the Emergency Department and Intensive Care Unit, polytrauma patients still have a high risk for developing infectious complications. Mannose Binding Lectin (MBL) is an important pattern recognition molecule in the innate immune system. It binds to many micro-organisms and activates the complement system through the lectin pathway.

The MBL2 gene, which codes for MBL, has several Single Nucleotide Polymorphisms (SNPs) that strongly decrease the amount of circulating MBL. Three SNPs are found in exon 1 (codon 52, 54 and 57; causing allele D, B and C respectively) and some are found in the promoter region (e.g. position -221, Y/X-variant). The different haplotypic combinations of these SNPs lead to a wide variety in serum MBL concentration.

Methods: In 104 consecutive polytrauma patients with ISS higher than 15 admitted to a level I trauma center DNA was isolated from a venous blood sample (QIAamp DNA Blood Mini Kit, QIAgen). SNPs in exon 1 and in the promoter region were determined with asymmetrical PCR followed by High Resolution Melting Analysis (HRMA) on a LightScanner (HR-96, Idaho Technology). Patient data were collected from the electronic patient files.

Results and conclusions: Genotyping was performed in 104 patients. Median age was 44 years (P25-P75 27-57) of which 82% was male. Fourty patients (38%) had SNPs in the promoter region and/or in exon 1 of the MBL2 gene. Thirtythree patients (32%) were heterozygous for the promoter SNP Y/X. In 35 of 104 patients (33%) one variant allele in exon 1 of the MBL2 gene was found (heterozygous): 12 times A/B, 6 times A/C, and 17 times A/D. In 5 patients (5%) a homozygously mutated haplotype was fouond (0/0). Median ISS score was 25 (P25-P75 18-34) as well in the SNP positive group as in the wildtype group. The number of positive wound cultures for A/A genotype was 59%, for A/0 genotype 80% and for 0/0 genotype 100% (p=0,032, Chi square). In ICU patients we found a trend towards more positive pulmonary sputum cultures (51% genotype A/A versus 67% genotype 0/0, NS) and a trend towards more positive blood cultures (22% genotype A/A versus 31% genotype A/0, NS).

In this study we found that 38% of polytrauma patients have MBL2 polymorphisms that code for low or absent amount of serum MBL. These patients have a significantly higher risk for positive wound cultures. A positive trend was found for sputum and blood cultures. Additional clinical data and more polytrauma patients are currently studied.