Serum Pregnancy-specific Beta 1-glycoprotein Research Articles

First trimester maternal serum pregnancy‐specific beta‐1‐glycoprotein (SP1) as a marker of adverse pregnancy outcome

To establish the first trimester levels of pregnancy-specific beta-1-glycoprotein (SP1) in pregnancies with adverse outcome. Furthermore, to determine the screening performance for adverse outcome using SP1 alone and in combination with other first trimester markers including proMBP and PAPP-A. A case-control study was conducted in a primary hospital setting. The SP1 concentration was measured in first trimester maternal serum in pregnancies with small-for-gestational age fetuses (SGA) (n = 150), spontaneous preterm delivery (n = 88), preeclampsia (n = 40) and in controls (n = 500). Concentrations were converted to multiples of the median (MoM) in controls and groups were compared using Mann-Whitney U-test. Logistic regression analysis was used to determine significant factors for predicting adverse pregnancy outcome. Screening performance was assessed using receiver operating characteristic (ROC) curves. The SP1 MoM median was significantly reduced in cases with SGA (0.76 MoM, p < 0.0005) and spontaneous preterm delivery (0.77 MoM, p < 0.0005) whereas no alteration was found in cases with preeclampsia (0.94 MoM, p = 0.723). A significant correlation (r = 0.217) between log(10)(SP1 MoM) and the birth weight percentile was found in the SGA group. Screening performance was only slightly improved when SP1 was combined with PAPP-A or proMBP. SP1 is a first trimester maternal serum marker of SGA and preterm delivery.

Serum pregnancy-specific beta1-glycoprotein before embryo transfer is related to endometrial thickness and to outcome prognosis in women undergoing in-vitro fertilization treatment.

We have previously observed the repeated presence of low but detectable amounts of the trophoblast marker pregnancy-specific beta1-glycoprotein (SP1) in the serum of some women undergoing in-vitro fertilization (IVF) treatment around the time of oocyte retrieval. The occurrence of these signals seemed to be restricted to a defined group of patients which also showed a lower pregnancy success rate in a preliminary study. To test our hypothesis we have analysed 173 consecutive cycles leading to an embryo transfer. Fifty-four cycles (31%) had a serum SP1 level of at least 0.1 ng/ml between days embryo transfer -5 and embryo transfer (group A). Five pregnancies were obtained in this group (pregnancy rate = 9.3%), while in group B, defined by the absence of detectable SP1 before embryo transfer (119 cycles), 36 ongoing pregnancies were achieved (30.3%). Ten of the 41 pregnancies were achieved in 33 first-time non-pregnant patients undergoing further attempts during the study period. Again the pregnancy rate was higher in the first-time group B women (9/23 versus 1/10 for group A). Patients tended to remain in their groups A or B, the latter being associated with a better immediate as well as subsequent chance for pregnancy. Group A cycles had a significantly lower endometrial thickness two days before oocyte retrieval than group B (P = 0.0011). We postulate that the presence of an unknown, maternal and progesterone- or follicle stimulating hormone-independent factor in some patients could stimulate tonic ectopic SP1 synthesis and at the same time negatively influence endometrial development.

Second trimester maternal serum pregnancy specific beta‐1 glycoprotein (SP‐1) levels in normal and down syndrome pregnancies

Maternal serum pregnancy specific beta-1 glycoprotein (SP-1) levels in the second trimester may be predictive of Down syndrome (DS). An enzyme immunoassay was used to measure SP-1 sera from 46 DS pregnancies and 117 normal control women matched for maternal age, gestational age, and length of storage. In the normal control samples, there were slight correlations between the SP-1 concentration and maternal age. The maternal serum SP-1 levels increased with each week of gestation from 15 to 20 weeks. All but one of the DS sera had SP-1 levels greater than the normal median. Using a cutoff of 2.8 multiples of the median (MoM), 15.2% of the DS pregnancies were detected with a false-positive rate of 4.3%. A combinational logistic regression analysis of maternal age and pregnancy related serum proteins will detect additional DS pregnancies and decrease the false-positive rate. The combination of maternal age and SP-1 detected 33 (71.7%) of Down syndrome pregnancies. The addition of maternal serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) levels allowed for the detection of 36 (78.3%) of the DS pregnancies with a decrease in the false-positive rate to 3.4%. The measurement of other serum constituents in conjunction with AFP appears to be a valuable addition to current screening programs, as this can increase the proportion of DS cases detected prenatally.

The serum pregnancy‐specific β1‐glycoprotein to betahuman chorionic gonadotrophin ratio as an index of prognosis in patients with choriocarcinoma

The ratio of serum pregnancy-specific beta 1-glycoprotein (SP1) to the beta-subunit of human chorionic gonadotrophin (beta-hCG) before and after chemotherapy was measured in 12 patients with metastatic choriocarcinoma. The ratios before chemotherapy ranged between 0.03 and 0.75, with a mean value of 0.34 (SD 0.21). The ratio increased to over 1.0 (1.05-53.3) after one or two courses of chemotherapy in seven of the 12 patients. These women achieved complete remission. In the other five patients who died of the disease due to drug resistance of the tumour, the ratio after chemotherapy was low (0.04-0.74) and tended to decline. These data suggest that the serum SP1/beta-hCG ratio can be used to predict the prognosis of patients with choriocarcinoma.

Predictive value analysis of measurements of human chorionic gonadotropin, pregnancy specific β1-glycoprotein, placental lactogen, and cystine aminopeptidase for the diagnosis of ectopic pregnancy

The diagnostic utility of serum and urinary human chorionic gonadotropin (hCG) measurements and serum measurements of pregnancy-specific beta 1-glycoprotein (PSBG), placental lactogen, and cystine aminopeptidase (CAP) was prospectively studied in 51 consecutive patients with suspected ectopic pregnancy who underwent laparoscopy or laparotomy. CAP was not detected in the sera of any patient with ectopic pregnancy. False-positive results in each assay were found in patients with intrauterine pregnancy or missed abortion. The overall efficiency of the tests were: urine hCG slide test, 47%; urine hCG tube test, 80%; serum hCG, 86%; serum PSBG, 82%; and human placental lactogen, 60%. Although measurement of serum hCG by radioimmunoassay is the most accurate biochemical test in predicting the correct diagnosis in patients with suspected ectopic pregnancy, the relatively high efficiency of the urinary hCG tube test, coupled with its ease of performance, low cost, and rapid turnaround time, makes it the most practical screening test.

Radioimmunoassay and Immunoperoxidase of Pregnancy Specific Beta-1 Glycoprotein in Sera and Tumor Cells of Patients with Certain Testicular Germ Cell Tumors

An immunohistologic study on 13 of 97 patients with germ cell tumors of the testis having elevated serum pregnancy specific beta-1 glycoprotein was undertaken to correlate the presence of this marker in the various cell types of this tumor. Four placentas were obtained from patients in the first trimester of pregnancy and studied for the presence of pregnancy specific beta-1 glycoprotein in various cells of this organ using an indirect immunoperoxidase technique. Specific beta-1 glycoprotein was demonstrated in the syncytiotrophoblastic component of choriocarcinoma. This placental marker also was localized in syncytiotrophoblastic giant cells occasionally associated with embryonal carcinoma, with or without teratoma. All 13 patients were chosen for the presence of an elevated level of pregnancy specific beta-1 glycoprotein in the sera. There was tissue localization of pregnancy specific beta-1 glycoprotein in 3 of 4 cases of choriocarcinoma (75 per cent), 4 of 4 samples of placenta (100 per cent), 4 of 5 cases of embryonal carcinoma (80 per cent) and 2 of 4 cases of teratocarcinoma (50 per cent).