Mannose-binding lectin (MBL2) and ficolin-2 (FCN2) polymorphisms in patients on peritoneal dialysis with staphylococcal peritonitis.
BACKGROUND
Mannose-binding lectin (MBL) and ficolin-2 (FCN) are activators of the lectin pathway of complement and act as primary defences against infection. Single-nucleotide polymorphisms (SNPs) in the MBL2 and FCN2 genes influence the functionality of the proteins. Both proteins are capable of binding staphylococci, which are pathogens that frequently cause peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD). We studied the role of polymorphisms in the MBL2 and FCN2 genes as a risk factor for developing CAPD peritonitis caused by staphylococci.


METHODS
We analysed SNPs in the MBL2 and FCN2 genes in 40 CAPD patients with staphylococcal peritonitis and in 65 CAPD patients without any history of peritonitis. Additionally, we analysed the prevalence of exit site infections and nasal Staphylococcus aureus carriage in both groups.


RESULTS
The + 6359C > T SNP leading to the Thr236Met amino acid alteration in the FCN2 gene, associated with decreased substrate binding, was significantly more prevalent in CAPD patients with a history of staphylococcal peritonitis compared with patients on CAPD without a history of peritonitis (P = 0.037). No difference was found in MBL2 genotypes between the two groups. In CAPD patients with a history of staphylococcal peritonitis, exit site infection with S. aureus was also more prevalent (P < 0.01), while S. aureus carriage was not (P = 0.073).


CONCLUSIONS
In addition to known risk factors such as exit site infection, the + 6359C > T SNP in the FCN2 gene might be a risk factor for staphylococcal peritonitis in CAPD patients due to decreased binding of FCN to staphylococci.
Meijvis
Sabine C A
SC
Department of Internal Medicine, St Antonius Hospital, Nieuwegein, The Netherlands. s.meijvis@antonius.net
Herpers
Bjorn L
BL
Endeman
Henrik
H
de Jong
Ben
B
van Hannen
Erik
E
van Velzen-Blad
Heleen
H
Krediet
Raymond T
RT
Struijk
Dirk G
DG
Biesma
Douwe H
DH
Bos
Willem Jan W
WJ
D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D005919:Glomerular Filtration Rate; D006801:Humans; D037102:Lectins / Q000235:genetics*; D008297:Male; D037601:Mannose-Binding Lectin / Q000235:genetics*; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000009:adverse effects*; D010538:Peritonitis / Q000209:etiology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000209:etiology*; D013211:Staphylococcus aureus / Q000235:genetics / Q000472:pathogenicity; D015996:Survival Rate; D000097604:Ficolins
D037102:Lectins; D037601:Mannose-Binding Lectin; D000097604:Ficolins; C445619:MBL2 protein, human