Decreased amount of mpl and reduced expression of glycoprotein IIb/IIIa and glycoprotein Ib on platelets from patients with refractory anemia: analysis by a non-isotopic quantitative ligand binding assay and immunofluorescence.
Using a non-isotopic ligand binding assay and immunofluorescence, we examined the amount of mpl, glycoprotein IIb/IIIa (gpIIb/IIIa) and glycoprotein Ib (gpIb) on platelets from healthy volunteers and patients with refractory anemia (RA). For the analysis of mpl expression, we applied both a non-isotopic ligand binding assay and immunofluorescence using anti-mpl monoclonal antibody, and compared the results from both methods. The non-isotopic ligand binding assay has been developed in our laboratory and is suitable for the quantitative analysis of a small amount of cytokine receptors such as mpl on platelets. In platelets from patients with RA, the amount of mpl expressed by the D value was 0.05+/-0.03 (mean+/-standard deviation), and was significantly lower than that in healthy volunteers (0.15+/-0.05, p<0.0001). The mean fluorescence intensities (MFI) of gpIIb/IIIa and gpIb on platelets from RA patients were 28.8+/-8.8 and 20.8+/-7.7, respectively, and were significantly lower than those on normal subjects (93.2+/-22.6 and 67.4+/-9.1, p<0.0001 and p<0.0001, respectively). There was a good correlation between the amount of mpl and the MFI of gpIIb/IIIa (p=0.794, p<0.0001) or gpIb (p=0.774, p<0.0001), and between those of gpIIb/IIIa and gpIb (p=0.728, p<0.0001). We demonstrated a decreased amount of mpl as well as a reduced expression of gpIIb/IIIa and gpIb on platelets from RA patients.
Izumi
M
M
Clinical Laboratories, Hamamatsu University School of Medicine, Japan.
Takeshita
A
A
Shinjo
K
K
Naito
K
K
Matsui
H
H
Shibata
K
K
Ohnishi
K
K
Kanno
T
T
Ohno
R
R
D000328:Adult; D000368:Aged; D000753:Anemia, Refractory / Q000097:blood*; D001667:Binding, Competitive; D001792:Blood Platelets / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D008297:Male; D008875:Middle Aged; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism*; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*; D011485:Protein Binding; D018709:Statistics, Nonparametric; D013926:Thrombopoietin / Q000378:metabolism*
D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019038:Platelet Glycoprotein GPIb-IX Complex; D013926:Thrombopoietin