COMPARISON OF BIOASSAY AND IMMUNOASSAY OF HUMAN CHORIONIC GONADOTROPHIN IN URINE

1965 ◽  
Vol 50 (3) ◽  
pp. 335-344 ◽  
Author(s):  
Rudi Borth ◽  
Michel Ferin ◽  
Annette Menzi

ABSTRACT In 39 samples of pregnancy urine, the concentration of human chorionic gonadotrophin (HCG) was estimated biologically by the ovarian hyperaemia reaction in rats, and serologically by the passive haemagglutinationinhibition technique. The results of the bioassays varied from 3 to 150 IU/ml, those of the immunoassays from 5 to 640 IU-eq./ml, and the correlation between the two (calculated for their logarithms) accounted for only 17 per cent of the total variation (r2 = 0.169, P ≈0.01). If the biological activity were estimated from a serological result and the appropriate regression line, the fiducial interval for P = 0.05 would extend from 17 to 610 per cent of the estimate. In a factorial experiment using three anti-HCG sera, three standard and three sensitizing preparations of HCG, the sensitivity of the serological system (expressed as the endpoint concentration in IU of HCG) varied considerably between the 27 combinations of the 3 factors, but there was no interaction between the latter. From these data and those of other authors, it is concluded that immunoassays based on haemagglutination inhibition cannot replace bioassays in the estimation of HCG, as distinct from its hypothetical metabolites or other related antigens, unless specificity has been demonstrated. The well-documented reliability of serological pregnancy tests is, of course, not in dispute. Attention is drawn to the fact that »statistically significant« correlation does not guarantee analytically acceptable agreement between two methods of assay.

1971 ◽  
Vol 67 (3) ◽  
pp. 434-444 ◽  
Author(s):  
D. L. Matthies ◽  
E. Diczfalusy

ABSTRACT Gel filtration of pregnancy urine on Sephadex G-100 separates two molecular species related to human chorionic gonadotrophin (HCG). One is a slightly retarded fraction which possesses biological activity but little or no immunological activity. The other is a highly retarded fraction which possesses immunological activity but no detectable biological activity. The highly retarded material could not be detected in pregnancy serum nor in extracts of first trimester placentas. A nonpregnant woman injected intravenously with purified HCG which displayed only slight retardation on the column produced urine which contained the highly retarded material. Experiments are described, the results of which suggest that the highly retarded material is a separate component of urine, probably generated by the kidney.


1964 ◽  
Vol 46 (4) ◽  
pp. 632-638 ◽  
Author(s):  
Bruce Hobson ◽  
Leif Wide

ABSTRACT When assayed against the International Standard for HCG the biological activity, as measured by the rat seminal vesicle method, of urines from women collected during the second half of pregnancy is lower than the immunological activity (haemagglutination inhibition reaction). Almost 100 % of the immunological and biological HCG activities were recovered from the acetone precipitates of such urines. A kaolin extract of these urines produced a partial separation of the immunological activity. About half of the immunological activity and almost all of the biological activity was recovered in the concentrate. In the supernatant, left after kaolin extraction, an immunologically active biologically inactive »HCG« was found. A urine from a woman with a hydatidiform mole was assayed by both methods. The biological and immunological activities of this urine were almost unity and the ratio of the 2 activities remained unaltered in the acetone precipitate and the kaolin concentrate made from an aliquot of this urine. The kaolin supernatant contained equal and measurable amounts of the biological and immunological activities. In conclusion the method used to concentrate the urine of pregnant women will affect the ratio between the biological activity and the immunological HCG activity.


1971 ◽  
Vol 67 (2) ◽  
pp. 262-276 ◽  
Author(s):  
P. Petrusz ◽  
C. Robyn ◽  
E. Diczfalusy

ABSTRACT Forty-two antisera were prepared in rabbits against human chorionic gonadotrophin (HCG), human hypophysial gonadotrophin (HHG), human urinary luteinizing hormone (LH) and human menopausal gonadotrophin (HMG) preparations. The gonadotrophic profiles of the antigens were previously characterized by bioassay, immunoassay and bioimmunoassay methods. The 25 most potent antisera were tested in statistically valid bioassays for their HCG and follicle stimulating hormone (FSH) neutralizing activities as well as for their neutralizing potencies against the FSH-like activity present in HCG preparations. The anti-HCG/anti-FSH ratios of the anti-HCG sera tested varied between 6.2 and > 254, while those of the anti-HHG, anti-LH and anti-HMG sera were close to 2. It was found that the total dose of immunological activity (anti-HCG neutralizing and anti-FSH neutralizing potency) rather than that of the biological activity administered to the rabbits was decisive for obtaining antisera with high anti-HCG and anti-FSH titers. Immunization with a highly purified HCG preparation (> 17 000 IU/mg) resulted in antisera exhibiting lower anti-HCG/anti-FSH ratios than did immunization with partially purified preparations. A highly purified urinary LH preparation which did not contain any detectable FSH activity gave rise to antisera exhibiting anti-HCG/anti-FSH ratios of approximately 2.0. These highly purified HCG and LH preparations were shown previously to possess high anti-FSH neutralizing potencies (Petrusz et al. 1971b). Booster injections did not change significantly the quality or the titer of the antigonadotrophic sera studied. The HCG neutralizing potency of anti-HCG sera was approximately 3 times higher when assayed against a highly purified HCG preparation (> 17 000 IU/mg) as compared to potency estimates obtained against the laboratory standard of HCG (about 2000 IU/mg). It is suggested that consideration should be given to the establishment of standard preparations of antigonadotrophic sera. It is concluded that bioimmunoassays are more suitably than conventional bioassay methods for the assessment of the antigenic purity of human gonadotrophin preparations.


1972 ◽  
Vol 55 (2) ◽  
pp. 363-368 ◽  
Author(s):  
BRUCE HOBSON ◽  
LEIF WIDE

SUMMARY Evidence is provided to show that chorionic gonadotrophins extracted from the human, rhesus monkey and marmoset placentae have antigenic determinants in common. Similar slopes were obtained for these gonadotrophins in a radioimmunoassay for human chorionic gonadotrophin (HCG). The biological activity of the monkey gonadotrophins was neutralized by anti-HCG serum. When the gonadotrophic activity of the monkey placental extracts was assayed biologically and immunologically, using HCG as a standard, similar results were obtained. Higher values were obtained by the immunoassay than by the bioassay when extracts of human placenta were assayed using the same HCG standard.


1967 ◽  
Vol 38 (4) ◽  
pp. 395-399 ◽  
Author(s):  
W. A. BARR ◽  
J. G. COLLEE

SUMMARY Incubation of a partially purified preparation of human chorionic gonadotrophin (HCG) with neuraminidase resulted in release of free sialic acid from the substrate. The biological activity of the HCG was considerably reduced after incubation with the enzyme, but a parallel reduction in immunological activity was not observed.


1978 ◽  
Vol 89 (3) ◽  
pp. 612-624 ◽  
Author(s):  
D. Puett ◽  
A. Kenner ◽  
R. Benveniste ◽  
D. Rabinowitz

1962 ◽  
Vol 39 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Leif Wide ◽  
Carl Gemzell

ABSTRACT An immunological method to assay human pituitary luteinizing hormone (HPLH) in urine is described. It is based on the fact that HPLH crossreacts with human chorionic gonadotrophin (HCG) in an haemagglutination inhibition reaction between HCG-coated blood cells and rabbit HCG-antisera. During the menstrual cycle the excretion of HPLH reached a peak of 200–400 U per liter at the time of ovulation. In the urine of post-menopausal women the concentration of HPLH was between 100 and 400 U per liter. In the urine of adult men the concentration of HPLH was between 50 and 160 U per liter.


1969 ◽  
Vol 61 (1) ◽  
pp. 89-95
Author(s):  
Rudi Borth ◽  
Annette Menzi

ABSTRACT In a study designed as a factorial experiment, the biological activity of standard solutions of human chorionic gonadotrophin in distilled water (A), saline (B), 1 % bovine serum albumin (C), 0.5 % gelatin (D), and borate buffer of pH 9 (E) was investigated under four different conditions of freezing and thawing, using the following three methods of bioassay: ovarian ascorbic acid depletion in rats (OAAD), uterine weight in mice (UW), and ovarian hyperaemia in rats (OH). Repeated freezing and thawing and prolonged storage at -15°C did not affect the potency in any test. In the OAAD test, the potency was increased 4–5fold by D, and 2–3fold by C. In the OH test, E augmented the potency 2–3fold. These findings are of interest in the practice of bioassay, in studying mechanisms of response, and regarding administration for therapeutic purposes. Diluents which possess augmenting properties could be used to improve the sensitivity of a bioassay if standard and unknowns showed the same degree of augmentation.


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