Single point estimation of platelet angiotensin II receptor number may not be valid screening test for pregnancy-induced hypertension.
1. Quantification of platelet angiotensin II (AII) receptors has been suggested as a screening test for pregnancy-induced hypertension (PIH). Saturation analysis is too technically demanding to screen the requisite numbers and although a simplified method has been proposed, it has not been validated against saturation. This study sought to compare the two methods. 2. Platelet AII receptor number was determined by saturation analysis and from the specific binding at each of three radioligand concentrations. The two methods were compared by correlation and by plotting their differences against their means to determine limits of agreement. 3. Significant correlations were observed at all three radioligand concentrations; however, none of the regression lines approached the line of equality. There was increasing scatter as receptor number increased and 95% confidence intervals were too large to be clinically useful. 4. From this study it is concluded that the simplified method for estimating platelet AII receptor number is inaccurate and caution is urged in its use as a screening test for PIH.
Yang
Y
Y
Hypertension Laboratory, Prince Henry Hospital, Sydney, New South Wales, Australia.
Pawlak
M A
MA
Macdonald
G J
GJ
Duggan
K A
KA
D000328:Adult; D001792:Blood Platelets / Q000737:chemistry*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000097:blood / Q000175:diagnosis*; D011869:Radioligand Assay; D011945:Receptors, Angiotensin / Q000032:analysis*
D011945:Receptors, Angiotensin