title: Serum concentration of complement components of the lectin pathway in maintenance hemodialysis patients, and relatively higher levels of L-Ficolin and MASP-2 in Mannose-binding lectin deficiency.
abstract: Mannose-binding lectin (MBL), L-ficolin and MBL associated serine protease-2 (MASP-2) are molecules involved in initiation of the lectin pathway (LP) in the complement system. Although MBL deficiency is observed in almost 10% of healthy people, studies of associations between MBL deficiency and end-stage renal disease (ESRD) remain rare. The objective of the present study is to clarify the significance of the LP in maintenance hemodialysis (HD) patients, especially in terms of MBL levels. Two hundred and forty-four HD patients who had been followed up for 74±84months and 199 healthy controls were included in this study. Measurements of serum concentrations of MBL, L-ficolin, and MASP-2 were performed. Low serum MBL levels (<0.1µg/mL) in the patients were confirmed by examination of a point mutation in the Mbl-2 gene. Seventeen HD patients (7%) and 20 healthy controls (10%) had MBL deficiency. During the follow-up period, 99 patients died. There was no significant difference in the frequency of deaths by infectious diseases between MBL deficient and non-deficient patients. In both patients and healthy controls with MBL deficiency, the serum concentration of L-ficolin tended to be high, and that of MASP-2 was significantly high (P<0.05). MBL deficiency is not a risk factor for HD induction or life-threatening infections. It is postulated that the elevation of concentration of the two components of the LP, L-ficolin and MASP-2, may compensate for the insufficient activity of the LP in MBL deficiency.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo             Department of Applied Biochemistry, Tokai University, Kanagawa, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Ishii
authors.forename: Isao
authors.initials: I
authors.lastname: Ohsawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inoshita
authors.forename: Gaku
authors.initials: G
authors.lastname: Kusaba
authors.forename: Kisara
authors.initials: K
authors.lastname: Onda
authors.forename: Michiro
authors.initials: M
authors.lastname: Wakabayashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horikoshi
authors.forename: Misao
authors.initials: M
authors.lastname: Matsushita
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tomino
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy*; D037102:Lectins / Q000097:blood*; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood* / Q000172:deficiency / Q000235:genetics; D050606:Mannose-Binding Protein-Associated Serine Proteases / Q000378:metabolism*; D008875:Middle Aged; D017354:Point Mutation; D006435:Renal Dialysis; D012307:Risk Factors; D000097604:Ficolins
chemical_list: D037102:Lectins; D037601:Mannose-Binding Lectin; D050606:Mannose-Binding Protein-Associated Serine Proteases; D000097604:Ficolins; C445619:MBL2 protein, human; C105296:MASP2 protein, human