[Studies on pregnancy specific beta 1-glycoprotein (SP1) by enzymeimmunoassay (author's transl)]

We developed a highly sensitive EIA for determination of SP1. The detection limit was 5ng/ml, and the correlation of EIA and RIA was extremely good (SAWAKI et al., 1980). Using this method, we found that SP1 was detected even in the serum at 12 days of ovulation. The concentration of SP1 in cord blood was on average 127ng/ml (24-540ng/ml). SP1 in newborn serum was 126ng/ml (22-355ng/ml) in 1st, and almost undetected in 4th day. SP1 in urine was 9.7ng/ml in the 5th week of pregnancy, 1,210ng/ml at peak in the 32th week, and in after delivery was 439ng/ml in 1st day and afterwards descended to 6ng/ml in 8th day. In 2 infertile women SP1 was detected in the sera of 14 days after ovulation. This suggests that SP1 measurment might be useful in the diagnosis of occult pregnancy. Three patients with throphoblastic disease were found to have regression curves for both HCG and SP1. The sera of 39 patients with uterine cervical carcinoma were examined to determine the occurrence of elevated SP1 levels. Ten of 27 patients before treatment had increased SP1 levels while only one of 12 patients had an increased SP1 level after treatment.