Double-label time-resolved immunofluorometric assay of prostate-specific antigen and of its complex with alpha 1-antichymotrypsin

We have developed a procedure for simultaneous immunofluorometric assay (IFMA) of prostate-specific antigen (PSA) and its complex with alpha 1-antichymotrypsin (ACT). A PSA-specific monoclonal antibody, which captures both free PSA and the PSA-ACT complex, was used as solid-phase antibody. Total PSA immunoreactivity was measured with a Eu(3+)-labeled PSA antibody that reacted with both free PSA and PSA-ACT. PSA-ACT was assayed simultaneously with a Sm(3+)-labeled polyclonal ACT antibody as a tracer. As standard we used pooled serum in which most of the PSA occurred as the PSA-ACT complex. The assay range was 0.03-500 micrograms/L for total PSA and 0.16-450 micrograms/L for PSA-ACT. In comparison with the assay for total PSA, assay of the PSA-ACT/PSA ratio improved the clinical specificity for cancer by reducing the number of false-positive results in prostatic hyperplasia.

Double-label time-resolved immunofluorometric assay of prostate-specific antigen and of its complex with alpha 1-antichymotrypsin

We have developed a procedure for simultaneous immunofluorometric assay (IFMA) of prostate-specific antigen (PSA) and its complex with alpha 1-antichymotrypsin (ACT). A PSA-specific monoclonal antibody, which captures both free PSA and the PSA-ACT complex, was used as solid-phase antibody. Total PSA immunoreactivity was measured with a Eu(3+)-labeled PSA antibody that reacted with both free PSA and PSA-ACT. PSA-ACT was assayed simultaneously with a Sm(3+)-labeled polyclonal ACT antibody as a tracer. As standard we used pooled serum in which most of the PSA occurred as the PSA-ACT complex. The assay range was 0.03-500 micrograms/L for total PSA and 0.16-450 micrograms/L for PSA-ACT. In comparison with the assay for total PSA, assay of the PSA-ACT/PSA ratio improved the clinical specificity for cancer by reducing the number of false-positive results in prostatic hyperplasia.

Concentrations of pancreatic secretory trypsin inhibitor (PSTI), acute phase proteins, and neopterin in Crohn's disease. Comparison with clinical disease activity and endoscopical findings

The usefulness of pancreatic secretory trypsin inhibitor (PSTI) as a marker of chronic inflammation was studied in patients with Crohn's disease. Pancreatic secretory trypsin inhibitor was compared with other laboratory tests (C-reactive protein, orosomucoid, and urinary neopterin), for evaluation of disease activity as measured by a clinical scoring system and endoscopical findings. The clinical utility of the tests was compared by four different methods. All tests showed significant differences in laboratory values between inactive and severely active disease. Using earlier established cut-off values PSTI showed the best combination of sensitivity and specificity for differentiation between inactive and severely active disease. When the efficacy of the test was compared by ROC-curve analysis, neopterin and orosomucoid produced the best combination of sensitivity and specificity, but for both assays the earlier established cut-off levels were too high for optimal separation between active and inactive disease. There was a poor agreement between endoscopically and clinically determined disease activity and the laboratory tests correlated better with clinical activity. The present study shows that serum PSTI reflects changes in the clinical activity of Crohn's disease equally well as C-reactive protein, which previously has been found to be an useful index of disease activity.

Relationship between carbohydrate metabolism and serum insulin-like growth factor system in postmenopausal women: comparison of endometrial cancer patients with healthy controls

Insulin is a major regulator of circulating insulin-like growth factor (IGF)-binding protein-1 (IGFBP-1), suppressing the hepatic production of IGFBP-1. Postmenopausal age, obesity, hypertension, and impaired glucose tolerance, which are known risk factors for endometrial cancer, are all associated with hyperinsulinemia and insulin resistance. In this study, we investigated the relationship among serum insulin, glucose, insulin-like growth factors (IGF-I and IGF-II), and IGFBP-, -2, and -3 in 32 nondiabetic postmenopausal women with endometrial cancer and in 18 healthy controls. The mean fasting levels of glucose and insulin were higher, whereas the mean basal IGF-I, IGF-II, and IGFBP-3 levels were lower in the endometrial cancer patients than in the healthy control subjects. The mean fasting IGFBP-1 and IGFBP-2 levels did not differ between the groups, and no correlation was found between fasting insulin and IGFBP-1 concentrations or between insulin and IGFBP-2 concentrations in either of the study groups. During an oral glucose tolerance test, the mean glucose levels at 1 and 3 h as well as the mean insulin level at 3 h were significantly higher in the endometrial cancer patients than in the controls, and the area under the glucose curve was larger in the first group. An oral glucose load resulted in a similar fall in serum IGFBP-1 levels in endometrial cancer patients and controls (51% and 55% at 3 h). When the cancer patients were divided into two subgroups according to the body mass index (kilograms per m2), the obese group had higher glucose and insulin indices than the nonobese group. No difference was found by the same measures in healthy controls. The fasting serum IGFBP-1 levels tended to be lower in the obese than in the normal weight subjects, but the difference did not reach statistical significance. In summary, these results provide preliminary evidence that the inverse relation between fasting insulin and IGFBP-1, well established in children and young adults, disappears in elderly women, although short term suppression by insulin still occurs. Further, our data indicate that in addition to carbohydrate metabolism, postmenopausal women with endometrial cancer have alterations in their circulating IGF system compared to controls.

Recurrent fever associated with progesterone action and persistently elevated serum levels of immunoreactive tumor necrosis factor-alpha and interleukin-6

We describe two women who suffer from recurrent fever up to 40 C in association with progesterone action and who have continuously elevated serum levels of immunoreactive tumor necrosis factor-alpha (TNF alpha) and interleukin-6 (IL-6). In patient 1, recurrent fever began at age 17 yr and has now continued for 11 yr. The patient has had three early pregnancy terminations because of continuous fever and, thereafter, three early pregnancy losses associated with fever. In patient 2, fever first appeared at age 18 yr, and the attacks have now continued for 3 yr. The association between fever and progesterone action is supported by the following facts. 1) The episodes of fever appear in the midluteal phase of the menstrual cycle concomitantly with the highest concentration of serum progesterone. 2) Fever is further exaggerated in early pregnancy. 3) Synthetic progestins induce fever regardless of the day of the menstrual cycle. 4) The progesterone antagonist RU 486 and an agonist of GnRH, nafarelin, are capable of preventing the fever, with no effect on serum cytokine levels. Although the underlying mechanism of elevated TNF alpha and IL-6 levels in our patients remains unknown, the data suggest that these cytokines cooperate with progesterone in exerting a pyrogenic response in the hypothalamic thermoregulatory center.

Optimization of a time-resolved immunofluorometric assay for tumor-associated trypsin inhibitor (TATI) using the streptavidin-biotin system

We have developed two 'sandwich'-type time-resolved immunofluorometric assays (IFMA) for tumor-associated trypsin inhibitor (TATI) using monoclonal and polyclonal antibodies. In the standard assay the monoclonal antibody was immobilized onto the walls of polystyrene microstrip wells and the polyclonal reagent was labeled with a europium chelate. We tested various assay conditions in order to optimize the assay for sensitivity and measuring range. Purification of the labeled antibody by hydrophobic interaction chromatography was found to be the most important single factor affecting sensitivity. Assay sensitivity and range were also improved by acid treatment of the solid phase antibody. To improve the sensitivity further the streptavidin/biotin (SAB) system was incorporated into the IFMA technique. In this simple and fast streptavidin/biotin IFMA (SAB-IFMA) we used streptavidin-coated wells to which we added biotinylated monoclonal antibody and a serum or urine sample. After incubation for 1.5 h and washing, the polyclonal europium-labeled tracer antibody was added. After incubation for 1 h the wells were washed and the Eu fluorescence measured. The assay performance of the SAB-IFMA was compared to the standard IFMA and radioimmunoassay (RIA). The detection limit was 0.05 microgram/l and the analytical range 3000-fold. The mean analytical recovery was 101%. Other advantages of the SAB-IFMA were high sensitivity and the low amounts of monoclonal antibody required, only 1/50 of that used in the standard IFMA.

Serum tumor markers CEA, CA 50, TATI, and NSE in lung cancer screening

BACKGROUND

There are no effective means for screening for lung cancer, so the authors assessed the utility of four lung cancer tumor makers for screening.

METHODS

A case-control study, nested in a cohort study based on the linkage of records of health survey examinees with Finnish Cancer Registry records, was used to test the validity of tumor markers carcinoembryonic antigen (CEA), tumor-associated trypsin inhibitor (TATI), neuron-specific enolase (NSE), and CA 50 in lung cancer screening. Ten years after health examinations, record linkage indicated that 187 men had lung cancer; 344 control subjects, matched for age, sex, and municipality were drawn from the same records.

RESULTS

The data allowed assessment of the sensitivity of the marker assays at a 95% specificity level, which was highest for CEA (17% at a concentration level of 5.3 micrograms/l). Logistic discrimination analysis indicated that of the other markers, only TATI, when used in combination, improved the discriminatory power of CEA. CEA and TATI levels correlated significantly with smoking. They also showed a significant gradient toward increasing risk of lung cancer from the lowest to the highest quintiles of marker levels (for CEA, crude relative risk between the highest and lowest quintiles, 8.6). The gradient also was evident in the subgroup whose cancer had been diagnosed more than 5 years after serum specimen collection. The trend persisted, although relative risk was halved after adjustment for smoking.

CONCLUSIONS

The markers do not seem to be useful tools for lung cancer screening. However, CEA and TATI levels seem to give information on cancer risk long before the clinical cancer stage, as the quintile-based analyses of marker levels indicate.

Polycystic ovaries and levels of gonadotrophins and androgens in recurrent miscarriage: prospective study in 50 women

OBJECTIVE

To compare the serum levels of gonadotrophins and androgens, as well as ovarian morphology, in 50 women with a history of recurrent miscarriage and in 20 healthy controls.

DESIGN

Prospective study on women with a history of at least three consecutive miscarriages in Department I and II of Obstetrics and Gynecology, University Central Hospital of Helsinki, Finland.

RESULTS

The recurrent miscarriage group as a whole exhibited gonadotrophin and androgen levels comparable to those seen in the controls. Ultrasound examination revealed polycystic ovaries (PCO) in 22 patients (44%) and in four control women (20%, P = 0.06) but no differences in the levels of gonadotrophins and androgens emerged between the patients with or without PCO. During follow up, 33 (66%) women with a history of recurrent miscarriage who became pregnant; 16 miscarried again (48.5%), whereas 17 (51.5%) succeeded. The presence of PCO did not predict miscarriage, but the patients who miscarried had higher levels of total testosterone, free testosterone and dehydroepiandrosterone sulphate than RSA women with continuing pregnancies.

CONCLUSIONS

PCO and hyperandrogenism may be associated with repeated miscarriage.

Serum tumor markers CEA, CA 50, TATI, and NSE in lung cancer screening

BACKGROUND

There are no effective means for screening for lung cancer, so the authors assessed the utility of four lung cancer tumor makers for screening.

METHODS

A case-control study, nested in a cohort study based on the linkage of records of health survey examinees with Finnish Cancer Registry records, was used to test the validity of tumor markers carcinoembryonic antigen (CEA), tumor-associated trypsin inhibitor (TATI), neuron-specific enolase (NSE), and CA 50 in lung cancer screening. Ten years after health examinations, record linkage indicated that 187 men had lung cancer; 344 control subjects, matched for age, sex, and municipality were drawn from the same records.

RESULTS

The data allowed assessment of the sensitivity of the marker assays at a 95% specificity level, which was highest for CEA (17% at a concentration level of 5.3 micrograms/l). Logistic discrimination analysis indicated that of the other markers, only TATI, when used in combination, improved the discriminatory power of CEA. CEA and TATI levels correlated significantly with smoking. They also showed a significant gradient toward increasing risk of lung cancer from the lowest to the highest quintiles of marker levels (for CEA, crude relative risk between the highest and lowest quintiles, 8.6). The gradient also was evident in the subgroup whose cancer had been diagnosed more than 5 years after serum specimen collection. The trend persisted, although relative risk was halved after adjustment for smoking.

CONCLUSIONS

The markers do not seem to be useful tools for lung cancer screening. However, CEA and TATI levels seem to give information on cancer risk long before the clinical cancer stage, as the quintile-based analyses of marker levels indicate.

Activin A/erythroid differentiation factor is induced during human monocyte activation

Activin A/erythroid differentiation factor (EDF), a dimeric polypeptide hormone composed of two beta A subunits, regulates growth and erythroid differentiation of human hematopoietic progenitor and erythroleukemia cells. We have identified activated human peripheral blood monocytes as a natural source of activin A/EDF. In these cells, lipopolysaccharide (LPS) induced rapidly the expression of the beta A subunit mRNAs through protein kinase C-dependent transcriptional regulation. The beta A subunit mRNA expression was also increased by 1,25-dihydroxyvitamin D3, an inducer of macrophage maturation of monocytes. Western analysis with an anti-beta A antibody and an erythroid differentiation bioassay confirmed that the conditioned media of LPS-activated monocytes contained the activin A/EDF protein. We suggest that monocyte/macrophage-derived activin A/EDF may not only modulate hematopoiesis but may also act as a mediator molecule in the diverse physiologic and pathogenetic events in which these cells are involved.

Absence of autoantibodies to human chorionic gonadotropin in women with a history of habitual abortion

OBJECTIVE

To determine if immunization to human chorionic gonadotropin (hCG) has occurred in women with habitual abortion.

DESIGN

Comparisons between nonpregnant patients with a history of at least three consecutive miscarriages (n = 48) and normal controls (n = 38). In addition, 28 habitual aborters were compared, while pregnant, with 37 pregnant control women. Antibodies to hCG were assessed by a solid-phase immunometric assay using europium-labeled antihuman immunoglobulin (Ig)G as tracer; this method is capable of detecting antibodies toward hCG in serum of patients immunized with beta-hCG-tetanus toxoid conjugate.

SETTING

Departments I and II of Obstetrics and Gynecology, University Central Hospital of Helsinki, Helsinki, Finland.

RESULTS

Three patients (1 primary and 2 secondary aborters, 1 both while pregnant and not pregnant) showed evidence of Ig binding to hCG, but the binding was not inhibited by an excess of hCG.

CONCLUSIONS

Antibodies against endogenous hCG may not be responsible for habitual abortion.

Concentrations of Human Choriogonadotropin, Its β-Subunit, and the Core Fragment of the β-Subunit in Serum and Urine of Men and Nonpregnant Women

Sensitive, specific time-resolved immunofluorometric assays were used to measure the concentrations of human choriogonadotropin (hCG), free beta-subunit (beta-hCG), and the core fragment of beta-hCG (c beta-hCG) in serum and urine of men and nonpregnant women without evidence of cancer. Concentrations of hCG and beta-hCG were measurable in 59-70% of serum samples and in 50-59% of urine samples. c beta-hCG was mostly undetectable in serum but measurable in 81% of urine samples. Concentrations were higher in women than in men, and hCG concentrations increased with age. Therefore, reference ranges based on the 97.5 percentile were calculated separately for women and men and for those < 50 and > 50 years. However, concentrations of hCG correlated much more strongly with those of follicle-stimulating hormone than with age. hCG concentrations in serum were similar to those reported before, but beta-hCG concentrations were below the detection limit of earlier assays, and the upper reference limit was one-fifth to one-tenth the cutoff concentrations used earlier. In urine, hCG and c beta-hCG were the major forms of hCG, and their concentrations were similar to those of hCG in serum.

Determination of Fetal Hemoglobin by Time-Resolved Immunofluorometric Assay

We have developed a "sandwich"-type time-resolved immunofluorometric assay (IFMA) for fetal hemoglobin (HbF) in hemolysates from adults and newborns, amniotic fluid, and plasma, based on a polyclonal and a monoclonal antibody against human fetal hemoglobin. Microtiter wells are coated with polyclonal capture antibody, and the gamma-chain-specific monoclonal tracer antibody is labeled with a europium chelate. In a simple and fast assay procedure, prediluted hemolysates are incubated in the microtiter wells first with capture antibody for 1 h and, after washing, for 1 h with tracer antibody. The wells are washed and the fluorescence of europium is measured. The mean analytical recovery is 102% and results by IFMA agreed well with values obtained by high-performance liquid chromatography. The analytical range of IFMA is large and well suited for clinical purposes. The detection limit of the assay is 0.2 microgram/L and the measuring range extends to 500 micrograms/L.

Concentrations of human choriogonadotropin, its beta-subunit, and the core fragment of the beta-subunit in serum and urine of men and nonpregnant women

Sensitive, specific time-resolved immunofluorometric assays were used to measure the concentrations of human choriogonadotropin (hCG), free beta-subunit (beta-hCG), and the core fragment of beta-hCG (c beta-hCG) in serum and urine of men and nonpregnant women without evidence of cancer. Concentrations of hCG and beta-hCG were measurable in 59-70% of serum samples and in 50-59% of urine samples. c beta-hCG was mostly undetectable in serum but measurable in 81% of urine samples. Concentrations were higher in women than in men, and hCG concentrations increased with age. Therefore, reference ranges based on the 97.5 percentile were calculated separately for women and men and for those < 50 and > 50 years. However, concentrations of hCG correlated much more strongly with those of follicle-stimulating hormone than with age. hCG concentrations in serum were similar to those reported before, but beta-hCG concentrations were below the detection limit of earlier assays, and the upper reference limit was one-fifth to one-tenth the cutoff concentrations used earlier. In urine, hCG and c beta-hCG were the major forms of hCG, and their concentrations were similar to those of hCG in serum.

Determination of fetal hemoglobin by time-resolved immunofluorometric assay

We have developed a "sandwich"-type time-resolved immunofluorometric assay (IFMA) for fetal hemoglobin (HbF) in hemolysates from adults and newborns, amniotic fluid, and plasma, based on a polyclonal and a monoclonal antibody against human fetal hemoglobin. Microtiter wells are coated with polyclonal capture antibody, and the gamma-chain-specific monoclonal tracer antibody is labeled with a europium chelate. In a simple and fast assay procedure, prediluted hemolysates are incubated in the microtiter wells first with capture antibody for 1 h and, after washing, for 1 h with tracer antibody. The wells are washed and the fluorescence of europium is measured. The mean analytical recovery is 102% and results by IFMA agreed well with values obtained by high-performance liquid chromatography. The analytical range of IFMA is large and well suited for clinical purposes. The detection limit of the assay is 0.2 microgram/L and the measuring range extends to 500 micrograms/L.

Elevation of free beta subunit of human choriogonadotropin and core beta fragment of human choriogonadotropin in the serum and urine of patients with malignant pancreatic and biliary disease

Human choriogonadotropin (hCG), its free beta subunit (beta hCG), and the core beta hCG fragment (c beta hCG) were measured by highly sensitive time-resolved immunofluorometric assays in the serum and urine of 29 patients with pancreatic cancer, 7 patients with biliary cancer, and 45 patients with benign pancreatic or biliary diseases. The results were compared with those of an age- and sex-matched reference population of nonpregnant women and men. Of the various forms of hCG assayed in serum, beta hCG showed the best diagnostic accuracy, and c beta hCG was the best marker in urine. Elevated serum concentrations of beta hCG were observed in 72% of the patients with pancreatic cancer, in 6 of 7 patients with biliary cancer, and in 9% of those with benign disorders. The serum concentrations of c beta hCG were elevated in 45%, 57%, and 2%, respectively, and those in urine in 55%, 71%, and 11%, respectively. The molar concentrations of c beta hCG in serum were mostly lower than those of beta hCG. Thus beta hCG secreted into serum appears to be the main source of c beta hCG in urine. Provided that they are measured by sufficiently sensitive and specific assays, beta hCG in serum and c beta hCG in urine appear to be useful markers for pancreatic and biliary cancer.

Expectant management of ectopic pregnancy

OBJECTIVE

To evaluate expectant management in selected cases of ectopic pregnancy.

METHODS

Transvaginal sonography and estimation of serum hCG concentrations were used in the evaluation and follow-up of ectopic pregnancy. Entry criteria for expectant management were: decreasing level of serum hCG, diameter of the ectopic pregnancy less than 4 cm, and no signs of rupture or acute bleeding by vaginal sonography.

RESULTS

Expectant management was studied in 83 patients, representing 26% of all ectopic pregnancies during a 2-year period. In 57 patients (69%), spontaneous resolution occurred, corresponding to 18% of all ectopic pregnancies. Laparoscopy was performed in 26 because of clinical symptoms or a rise in hCG level after expectant management for 1-18 days. One patient had a tubal rupture requiring tubal resection by laparoscopy. No serious complications occurred. With increasing experience, the rate of expectant management and spontaneous resolution increased during study period.

CONCLUSION

Expectant management with repeated vaginal sonography and estimations of serum hCG concentrations is a useful form of treatment for ectopic pregnancy in selected cases.

Elevated HbA1 due to foetal haemoglobinaemia in children. A common artifact of certain ion-exchange chromatography methods

Foetal haemoglobin (HbF) is known to elute with glycosylated haemoglobins (HbA1) in mini-column ion-exchange chromatography, thus producing falsely elevated values for HbA1 in subjects with foetal haemoglobinaemia. We studied the occurrence of this methodological artifact in 266 patients with suspected or known insulin-dependent diabetes mellitus (IDDM) and in 205 healthy children of various age groups. HbA1 was measured using ion-exchange chromatography with prefabricated mini-columns and HbA1c and HbF by high-performance liquid chromatography (HPLC). In healthy children of over 5 years of age, the HbA1 values were usually within the reference limits for adults. However, 69% of the children younger than 1 year of age and 7% of those 1-5 years of age had HbA1 levels above 10%. Their HbA1c values were normal but the HbF values were high. Six of the 223 patients with IDDM (2.7%) and three of the 43 patients with stress glucosuria (7%) had much higher HbA1 than HbA1c values. The discrepancy was again related to the presence of raised concentrations of HbF. We conclude that foetal haemoglobinaemia is more prevalent than was previously known, especially among children younger than 5 years of age. Presence of HbF will bias the use of HbA1 as a diagnostic aid or as an index of metabolic control in children with IDDM. Methods specific for HbA1c, such as HPLC, should be used in paediatric patients.

Chemotherapy as initial treatment for cervical carcinoma: clinical and tumor marker response

Chemotherapy was given as initial therapy to 23 patients with previously untreated early and advanced cervical carcinoma. A combination of cisplatin and VP-16 was given in squamous cell carcinoma, and cisplatin, epirubicin and cyclophosphamide in adenocarcinoma in one to three courses at 4-week intervals. The overall clinical response rate to initial chemotherapy was 78% (80% in early and 78% in advanced disease). A complete response was achieved in 3 (13%) and a partial response in 15 (65%) patients. To obtain independent information on treatment response serial tumor marker determinations were used in patients with elevated pretreatment levels. Squamous cell carcinoma antigen (SCC) responded to chemotherapy by decreasing levels in 91% of the cases, carcinoembryonic antigen (CEA) in 33%, CA 125 in 83%, and tumor-associated trypsin inhibitor (TATI) in 50%, respectively. These results show that cervical carcinoma is a drug-responsive tumor and that SCC and CA 125 can be used as an aid in the evaluation of response to chemotherapy. Initial chemotherapy appears be of value by reducing tumor volume thus providing better conditions for surgery and radiotherapy.

Developmental changes in 24-hour profiles of luteinizing hormone and follicle-stimulating hormone from prepuberty to midstages of puberty in boys

To establish the pubertal changes in gonadotropin secretion, 24-h secretory profiles of LH and FSH were studied in 10 healthy boys by ultrasensitive (sensitivity, 0.019 and 0.014 IU/L, respectively) time-resolved immunofluorometric assays 21 times. Five of the 10 boys were sampled on 2-6 occasions over a time interval of 0.95-6.4 yr. When sampled, 6 boys were prepubertal (testicular volume, less than 3 mL), 8 boys were early pubertal (testicular volume, 3-5 mL), and 7 boys were midpubertal (testicular volume, 10-25 mL). Plasma was taken every 20 min for 24 h. All boys had LH and FSH pulses. In prepuberty, the mean LH level was much lower than the mean FSH level, and neither showed significant diurnal variation. In early puberty, the mean LH level increased much more than that of FSH. For LH, the increase in mean levels was due to an increase in both pulse amplitude and frequency. During early and midpuberty, these changes were most marked at night, leading to the appearance of diurnal variation. For FSH, the mean levels increased progressively from prepuberty to midpuberty, with a slight increase in the mean pulse amplitude at the onset of puberty, whereas no change in pulse frequency was found. In contrast to LH, no diurnal variation was found for FSH at any of the pubertal stages. Thus, at the onset of puberty, gonadotropin secretion undergoes specific changes, which are different for LH and FSH, involving changes in pulse amplitudes and frequencies and development of diurnal variation for LH.