Relationship between oligomer and functional serum mannose-binding lectin in chronic renal failure.
BACKGROUND
Mannose-binding lectin (MBL) plays an important role in first-line host defence against pathogens via the lectin pathway. The binding affinity for ligands is greatly increased by oligomerization, although the basic triplet does not bind solid phase mannan and cannot activate complement. Besides, MBL is a positive acute-phase protein. In this study, we examined the relationship between oligomer and functional serum MBL in chronic renal failure patients who were either uraemic [Pre-haemodialysis (pre-HD) patients], or who were receiving maintenance haemodialysis treatment (HD patients).


METHODS
This study included a total of 20 Pre-HD patients, 130 HD patients and 28 healthy subjects. The oligomer and functional serum MBL levels were measured using enzyme-linked immunosorbent assays established previously.


RESULTS
The median serum functional MBL levels were significantly reduced in both Pre-HD and HD patients compared with healthy subjects (P<0·05 for both). Furthermore, the median functional MBL level in Pre-HD patients was significantly lower than that in HD patients (P<0·05). The median serum oligomer MBL levels in both Pre-HD and HD patients were significantly higher compared with healthy subjects (P<0·05 for both). Furthermore, the median oligomer MBL level in HD patients was significantly (P<0·05) higher than that in Pre-HD patients. The ratios of median serum functional MBL levels to oligomer MBL levels were significantly reduced in both Pre-HD and HD patients compared with healthy subjects (P<0·05 for both).


CONCLUSIONS
We found significant reductions in the ratios of serum functional MBL levels to oligomer MBL levels in HD and Pre-HD patients compared with healthy subjects.
Satomura
Atsushi
A
Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, Itabashi, Tokyo, Japan. atsushis@med.nihon-u.ac.jp
Fujita
Takayuki
T
Fuke
Yoshinobu
Y
Yanai
Mitsuru
M
Kumasaka
Kazunari
K
Takayama
Eiichi
E
Hamada
Hiroaki
H
Maruyama
Toshiharu
T
Nakayama
Tomohiro
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood*; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood* / Q000378:metabolism; D008875:Middle Aged; D006435:Renal Dialysis
D037601:Mannose-Binding Lectin; D002097:C-Reactive Protein