title: Increased activity of the mannan-binding lectin complement activation pathway in patients with colorectal cancer.
abstract: BACKGROUND
  Postoperative bacterial infectious complications are frequent in patients with colorectal cancer (CRC), with subsequent increased recurrence rates and poor prognosis. Deficiency of the mannan-binding lectin (MBL) complement activation pathway may cause increased risk of infection in certain patient groups. It is hypothesized that a deficient MBL pathway might be more frequent among patients with CRC than in healthy individuals. The MBL pathway was therefore evaluated in serum obtained preoperatively from 193 patients with primary CRC and in serum from 150 healthy volunteers.
  
  
  METHODS
  Serum MBL concentrations and MBL/MASP activity were determined using immunofluorometric assays. The levels are presented as the median, inter-quartile range and range.
  
  
  RESULTS
  Serum MBL levels were significantly (P < 0.0002) increased in patients with colorectal cancer (1384 (400-2188) ng/mL) (median, inter-quartile range) compared with levels in healthy blood donors (924 (230-1476) ng/mL). Similarly, the MBL/MASP activity was significantly (P < 0.0002) increased in patients (584 (202-914) mU/mL) compared with in blood donors (319 (0-684) mU/mL). This was independent of age, gender, tumour location in the colon or rectum, and disease stages according to Dukes' classification. No statistical difference (P=0.20) in frequency of MBL deficiency was found between the patients (20%) and the donors (27%).
  
  
  CONCLUSIONS
  Overall, the MBL complement activation pathway is significantly increased in patients with colorectal cancer compared with healthy persons. However, similar frequencies of MBL pathway deficiency are observed in patients and healthy persons.
authors.affiliation: Department of Surgical Gastroenterology, Hvidovre University Hospital, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark. ytting@dadlnet.dk
authors.forename: H
authors.initials: H
authors.lastname: Ytting
authors.forename: J C
authors.initials: JC
authors.lastname: Jensenius
authors.forename: I J
authors.initials: IJ
authors.lastname: Christensen
authors.forename: S
authors.initials: S
authors.lastname: Thiel
authors.forename: H J
authors.initials: HJ
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000097:blood / Q000276:immunology* / Q000473:pathology; D037582:Complement Pathway, Mannose-Binding Lectin / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood; D050606:Mannose-Binding Protein-Associated Serine Proteases; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000097:blood / Q000276:immunology* / Q000473:pathology; D012697:Serine Endopeptidases / Q000097:blood
chemical_list: D037601:Mannose-Binding Lectin; C105296:MASP2 protein, human; D050606:Mannose-Binding Protein-Associated Serine Proteases; D012697:Serine Endopeptidases