Measurement of vitamin D-binding protein in pleural fluids and sera by means of a turbidimetric immunoassay measuring system.
BACKGROUND
Vitamin D-binding protein (DBP) has been recognized as a multifunctional plasma protein that can modulate certain immune and inflammatory responses. There may be differences between the DBP concentrations in pleural fluids from various diseases involving a variety of possible responses in the pleural cavity.


METHODS
An anti-DBP polyclonal antibody was prepared using commercially available DBP to establish a quantitative measuring system for DBP. With a rabbit antibody, a turbidimetric immunoassay (TIA) was developed for DBP with an automatic analyzer. Using this measuring system, the concentrations of DBP were compared with the protein concentration in pleural fluid and serum specimens from patients with various diseases.


RESULTS
The fluid DBP concentrations in transudative (n=11) and exudative (n=41) effusions were 71.9+/-21.2 and 180.7+/-43.7 mg/l, respectively. Among the exudative effusions, the fluid DBP concentrations in the bacterial (n=10), tuberculous (n=13), and malignant (n=18) effusions were 218.8+/-37.3, 186.7+/-26.2, and 155.1+/-41.3 mg/l, respectively. The DBP fluid/serum ratio and the fluid DBP/protein ratio in bacterial effusions were significantly higher than those in tuberculous (p<0.005, p<0.05, respectively) and malignant effusions (p<0.0005, p<0.005, respectively), although no statistically significant differences in the serum DBP/protein ratio between those effusions were found.


CONCLUSIONS
Using the TIA assay, the DBP concentrations in bacterial pleural effusions were significantly higher than in tuberculous and malignant effusions.
Hamashima
Yoshio
Y
Department of Respiratory Medicine, Koshigaya Hospital, Dokkyo University School of Medicine, 2-1-50 Minamikoshigaya, Saitama, 343-8555, Japan. yham@dokkyomed.ac.jp
Kanazawa
Takemasa
T
Hirata
Atsuko
A
Yamai
Yosuke
Y
Fujihara
Hiroki
H
Sekine
Kaori
K
Nagao
Kosyu
K
D000368:Aged; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D015153:Blotting, Western; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D010994:Pleura / Q000737:chemistry*; D010996:Pleural Effusion; D011817:Rabbits; D012015:Reference Standards; D012680:Sensitivity and Specificity; D014809:Vitamin D-Binding Protein / Q000032:analysis* / Q000097:blood* / Q000276:immunology
D000906:Antibodies; D014809:Vitamin D-Binding Protein