title: Mannose-binding lectin levels during pregnancy: a longitudinal study.
abstract: BACKGROUND
  Pregnancy is associated with changes in the immune system. Although previous studies have focussed mainly on adaptive immunity, there are indications that components of innate immunity, such as mannose-binding lectin (MBL), are associated with pregnancy outcome. Although this would suggest that pregnancy also involves adaptations in innate immunity, there are few studies in this area. Therefore, we aimed to determine whether MBL concentrations and the following steps in complement pathway activation are influenced by pregnancy.
  
  
  METHODS
  MBL and Ficolin-2 concentrations, MBL-MBL-associated serine protease (MASP) complex activity, MBL pathway activity and classical complement pathway activity were determined by enzyme-linked immunosorbent assay (ELISA) in sera from pregnant women (n=32) during each trimester and post-partum. MBL genotyping was performed by PCR.
  
  
  RESULTS
  During pregnancy, MBL concentrations increased to 140% [interquartile range (IQR) 116-181%, P < 0.0001]. This increase was already present at 12 weeks of pregnancy and was most pronounced in the high-production AA-genotype. Directly Post-partum MBL concentrations dropped to 57% of baseline (IQR 44-66%, P < 0.0001). Variations in MBL levels were reflected by similar changes in the following steps of complement activation, r > 0.93 (P < 0.01). Ficolin-2 levels and classical complement pathway activity were not similarly influenced by pregnancy.
  
  
  CONCLUSIONS
  Pregnancy and the post-partum period profoundly influence MBL serum concentration and MBL complement pathway activity.
authors.affiliation: Department of Rheumatology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands. f.vandegeijn@erasmusmc.nl
authors.forename: F E
authors.initials: FE
authors.lastname: van de Geijn
authors.forename: A
authors.initials: A
authors.lastname: Roos
authors.forename: Y A
authors.initials: YA
authors.lastname: de Man
authors.forename: J D
authors.initials: JD
authors.lastname: Laman
authors.forename: C J M
authors.initials: CJ
authors.lastname: de Groot
authors.forename: M R
authors.initials: MR
authors.lastname: Daha
authors.forename: J M W
authors.initials: JM
authors.lastname: Hazes
authors.forename: R J E M
authors.initials: RJ
authors.lastname: Dolhain
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003171:Complement Pathway, Classical / Q000502:physiology; D005260:Female; D006801:Humans; D037102:Lectins / Q000097:blood; D008137:Longitudinal Studies; D037601:Mannose-Binding Lectin / Q000097:blood* / Q000235:genetics; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000378:metabolism; D011110:Polymorphism, Genetic; D049590:Postpartum Period; D011247:Pregnancy / Q000276:immunology*; D011248:Pregnancy Complications / Q000235:genetics; D000097604:Ficolins
chemical_list: D037102:Lectins; D037601:Mannose-Binding Lectin; D050606:Mannose-Binding Protein-Associated Serine Proteases; D000097604:Ficolins