Measurement of human plasma phospholipid transfer protein by sandwich ELISA.
BACKGROUND
Plasma phospholipid transfer protein (PLTP) plays a central role in the remodeling of HDLs. Reliable and accurate methods for assaying PLTP concentration are required.


METHODS
A sandwich ELISA for PLTP has been developed, using two monoclonal antibodies against recombinant human PLTP (rhPLTP) expressed in Chinese hamster ovary cells. The ELISA allows for the quantification of PLTP in the range 0.625-15.0 ng/assay (1.2-30.0 mg/L). Intra- and interassay CVs were <3.0% and <4.2% respectively. The assay was used to quantify plasma PLTP concentrations in 132 Japanese subjects (75 males and 57 females).


RESULTS
PLTP concentrations were 12.0 +/- 3. 0 mg/L (mean +/- SD; range, 4.9-20.5 mg/L). No sex difference was observed. Plasma PLTP concentration was positively correlated with HDL-cholesterol (r = 0.72; P: <0.001), apolipoprotein (apo) A-I (r = 0.62; P: <0.001) and HDL(2)-cholesterol (r = 0.72; P: <0.001), and was negatively correlated with triacylglycerol (r = -0.45; P: <0. 001). There was no correlation with plasma apo A-II. These results agree with other evidence that plasma PLTP is associated with large apo A-I-containing lipoproteins. There was no correlation (r = -0. 01) between plasma PLTP and plasma phosphatidylcholine transfer activity (range, 3.5-10.5 micromol. mL(-1). h(-1)), suggesting that PLTP may exist in active and inactive forms.


CONCLUSIONS
This new ELISA will be of value for further studies of PLTP in health and disease.
Oka
T
T
Research Division, R & D Center, BML, Inc., 1361-1 Matoba, Kawagoe, Saitama 350-1101, Japan.
Kujiraoka
T
T
Ito
M
M
Nagano
M
M
Ishihara
M
M
Iwasaki
T
T
Egashira
T
T
Miller
N E
NE
Hattori
H
H
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D016466:CHO Cells; D002138:Calibration; D002352:Carrier Proteins / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D008875:Middle Aged; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D008565:Membrane Proteins; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids; D011994:Recombinant Proteins