title: Bipolar and panic disorders may be associated with hereditary defects in the innate immune system.
abstract: BACKGROUND
  Mannan-binding lectin (MBL) and mannan-binding lectin-associated serine protease-2 (MASP-2) represent important arms of the innate immune system, and different deficiencies may result in infections or autoimmune diseases. Both bipolar and panic disorders are associated with increased inflammatory response, infections and mutual comorbidity. However, associations with MBL, MASP-2 or the gene, MBL2, coding for MBL, have not been investigated thoroughly.
  
  
  METHODS
  One hundred patients with bipolar disorder, 100 with panic disorder and 349 controls were included. Serum concentrations of MBL and MASP-2 were measured and seven single nucleotide polymorphisms (SNPs) influencing these concentrations were genotyped. Disease association with genetic markers and serum levels were investigated.
  
  
  RESULTS
  In panic disorder, we observed a large proportion (30%) of MBL deficient (<100ng/ml) individuals and significantly lower levels of MBL and MASP-2 plus association with the MBL2 YA two-marker haplotype. Bipolar disorder was associated with the MBL2 LXPA haplotype and lower MASP-2 levels.
  
  
  CONCLUSIONS
  No information on course or severity of disorders was included, and only MBL and MASP-2 were measured, excluding other components from the complement pathway. Restrictions defined by ethnical committees preclude information of control׳s ethnic origin.
  
  
  CONCLUSIONS
  Significant differences in MBL and MASP-2 concentrations were observed between cohorts, especially an intriguing finding associating panic disorder with MBL deficiency. These differences could not be fully explained by allele or haplotype frequency variations. Since MBL deficiency is highly heterogeneous and associated with both infectious and autoimmune states, more research is needed to identify which complement pathway components could be associated with bipolar respectively panic disorder.
authors.affiliation: Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Bioinformatics Research Centre, Aarhus University, Aarhus, Denmark; iPSYCH: The Lundbeck Foundation Initiative for Integrated Psychiatric Research, Aarhus and Copenhagen, Denmark. Electronic address: Leslie@birc.au.dk.
authors.forename: Leslie
authors.initials: L
authors.lastname: Foldager
authors.affiliation: iPSYCH: The Lundbeck Foundation Initiative for Integrated Psychiatric Research, Aarhus and Copenhagen, Denmark; Research Department P, Aarhus University Hospital, Risskov, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Köhler
authors.affiliation: Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Rudi
authors.initials: R
authors.lastname: Steffensen
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Steffen
authors.initials: S
authors.lastname: Thiel
authors.affiliation: Regional Psychiatric Services West, Central Denmark Region, Herning, Denmark.
authors.forename: Ann Suhl
authors.initials: AS
authors.lastname: Kristensen
authors.affiliation: Department of Biomedicine, Aarhus University, Aarhus, Denmark.
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Jensenius
authors.affiliation: iPSYCH: The Lundbeck Foundation Initiative for Integrated Psychiatric Research, Aarhus and Copenhagen, Denmark; Research Department P, Aarhus University Hospital, Risskov, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Mors
mesh_terms: D001714:Bipolar Disorder / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D005787:Gene Frequency; D056726:Genetic Association Studies; D006239:Haplotypes; D006579:Heterozygote; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D015810:Linkage Disequilibrium; D037601:Mannose-Binding Lectin / Q000097:blood / Q000172:deficiency / Q000235:genetics*; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000235:genetics* / Q000378:metabolism; D016584:Panic Disorder / Q000235:genetics* / Q000276:immunology; D020641:Polymorphism, Single Nucleotide
chemical_list: D037601:Mannose-Binding Lectin; C105296:MASP2 protein, human; D050606:Mannose-Binding Protein-Associated Serine Proteases
keywords: Bipolar disorder; Innate immune system; Mannan-binding lectin (MBL); Mannan-binding lectin-associated serine protease-2 (MASP-2); Panic disorder