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Secretory immunoglobulin A (SIgA) in serum is possibly the best index of SIgA presence in mucosal secretions in digestive tract and the mirror of its immunologic barrier against many pathogenic aggressions. The measurement of salivary SigA alone may be affected by total salivary secretion and its final concentration in the gland lumen is probably not useful as an appropriate index of mucosal secretions in the digestive tract. The usefulness of the determination of SigA against various epitopes in serum from patients with various autoimmune disease has been demonstrated. The aetiology of many digestive related disorders could be triggered by an alteration of mucose SIgA barrier. The determination of Igs is important for different liver diseases and specifically the SIgA in autoimmune diseases such as rheumatoid arthritis. We developed an easy and efficient immunologic assay to quantify SIgA in serum samples.

Low folate concentrations are inversely associated with birth defects, including neural tube defects, congenital heart disease and oral clefts. Conversely, high folate concentrations may be associated with adverse outcomes, including increased risk of colorectal cancer among those with pre-existing neoplasms. The purpose of our study was to investigate the folate status of a nationally representative sample of Canadians, including a subset of women of childbearing age.We examined red blood cell folate concentrations among members of the general population aged 6-79 years (n = 5248) and separately among women of childbearing age (15-45 yr, n = 1162), as recorded by the Canadian Health Measures Survey and measured by immunologic assay. We assessed the data for significant differences by age, sex and socioeconomic status.Less than 1% of Canadians showed folate deficiency (red blood cell folate305 nmol/L) and 40% showed high folate concentrations (1360 nmol/L). Among women of childbearing age, 22% showed concentrations below those considered optimal for maximal neural tube defect-risk reduction (906 nmol/L). Significant differences by age and socio-economic status, but not sex, were evident in median red blood cell folate concentrations, although concentrations in all groups exceeded recommended levels. No differences by age or income were found among women of child-bearing age.Folate deficiency is virtually nonexistent in the Canadian population, although high folate concentrations are evident. Additional research is needed to better understand the determinants of red blood cell folate among women of childbearing age who have concentrations below levels that are maximally protective against neural tube defects. Ongoing monitoring of the folate status of Canadians and the relationship between red blood cell folate and health outcomes is warranted.

The prediction of efficacy of Neisseria meningitidis serogroup B (MenB) vaccines is currently hindered due to the lack of an appropriate correlate of protection. For outer membrane vesicle (OMV) vaccines, immunogenicity has primarily been determined by the serum bactericidal antibody (SBA) assay and OMV enzyme-linked immunosorbent assay (ELISA). However, the opsonophagocytic assay (OPA), surface labeling assay, whole blood assay (WBA), and salivary antibody ELISA have been developed although correlation with protection is presently undetermined. Therefore, the aim of the study was to investigate further the usefulness of, and relationships between, MenB immunologic assays. A phase II trial of the OMV vaccine, MenBvac, with proven efficacy was initiated to compare immunologic assays incorporating the vaccine and six heterologous strains. Correlations were achieved between the SBA assay, OMV ELISA, and OPA using human polymorphonuclear leukocytes and human complement but not between an OPA using HL60 phagocytic cells and baby rabbit complement. Correlations between the surface labeling assay, the SBA assay, and the OMV ELISA were promising, although target strain dependent. Correlations between the salivary antibody ELISA and other assays were poor. Correlations to the WBA were prevented since many samples had results greater than the range of the assay. The study confirmed the immunogenicity and benefit of a third dose of MenBvac against the homologous vaccine strain using a variety of immunologic assays. These results emphasize the need for standardized methodologies that would allow a more robust comparison of assays between laboratories and promote their further evaluation as correlates of protection against MenB disease.

There have been significant advances in the development and application of novel therapeutic approaches and improved diagnostics for cancer in the past decade. Manipulation and/or assessment of cancer-specific immunity have been central to these advances. Murine models are a standard for the preclinical development of cancer immunotherapeutics. However, critical advances in our understanding of the role of the immune microenvironment and the assessment of cancer-specific immunity have not been fully applied to rodent models. Methods to preserve the function of immune cells after cryopreservation and standard approaches to quantitative immune assays have not been developed. Furthermore, a detailed evaluation of the immune tumor environment, which can impact a clinical response to different agents, is rarely undertaken as models are being contemplated. Rapid translation of immunoncology agents to the clinic will require standardization of immunologic assay methods and a more detailed immunologic characterization of common mouse models. Outlined here are the critical elements in assessing immunity in cancer mouse models and suggestions concerning the standardization of approaches when using these models for the study of immunoncology.

Background: Neonatal screening for steroid 21-hydroxylase (CYP21) deficiency is performed to identify congenital adrenal hyperplasia (CAH). The immunologic assay for 17α-hydroxyprogesterone (17-OHP) has a high rate of false positives. We assessed the potential for increasing the specificity for CAH by use of a second step involving analysis of the CYP21 gene. Methods: Between January 1999 and December 2003, a total of 810 000 newborns were screened. Of these, 7920 had to be retested because their 17-OHP values were above the cutoff of the assay. Sixty-one had positive 17-OHP values in their recall samples and were diagnosed as having CAH. We used a rapid assay for common mutations of the CYP21 gene to analyze these 61 samples. In a prospective study, 198 consecutive samples that had increased 17-OHP and 100 samples that had normal 17-OHP concentrations were genotyped. Results: Fifty-nine of 61 cases diagnosed as having CAH were confirmed genetically as CYP21 deficiencies. One patient had a 3β-hydroxysteroid dehydrogenase deficiency, and one patient carried no CYP21 mutations. The 198 increased 17-OHP results were designated as false positives after immunologic testing of recall samples. None of these samples exhibited the genetic pattern consistent with CYP21 deficiency. Conclusions: If samples with increased 17-OHP values were screened genetically, the number of retests would decrease by ∼90%, but the overall sensitivity of CAH screening would remain the same. Adding a second-tier genetic step would require a modest increase in costs, but is counterbalanced by fewer recalls, less clinical follow-up, and a reduction in unnecessary worry for families.

SUMMARY The discipline and techniques of immunology have been an important part of recent advances in genitourinary oncology. Although the initial promise of tumor immunology has not been realized in man, discoveries in the laboratory are revitalizing the expectation that this field will yet be of significant assistance in the diagnosis and treat ment of cancer. Already tumor immunology studies along with new immunologic assay techniques have produced clinically important tumor markers, such as alpha-fetoprotein, human chorionic gonadotropin, and prostatic acid phosphatase, and have intensified the search for other markers. Finally, research activity is increasingly focusing on the tumor cell itself, again often using immunologic methods. Although most of this activity is still experimental, analysis of bloodgroup antigens in transitional cell carcinoma has produced sufficient data to suggest that such an approach will soon be a part of the urologist’s clinical armamentarium in his efforts to treat patients with bladder tumors.

SummaryProtein C is a vitamin K dependent protein involved in blood coagulation. A congenital deficiency in protein C antigen - which inherits as an autosomal dominant disorder - has been reported to be associated with a high risk for thrombo-embolic disease at relatively young age. In the present paper we report on the development of a functional assay for plasma protein C. In this assay protein C is adsorbed to Al(OH)3, eluted and activated by thrombin, after which the concentration of the activated protein C is measured with a peptide substrate (S2366). Normal values for protein C activity and protein C antigen were determined in healthy volunteers and patients on stable oral anticoagulant treatment. Protein C activity and antigen levels were compared in 28 patients from 9 different pedigrees with both congenital protein C deficiency and thrombotic disease. Two types of protein C deficiency could be recognized: in type I the deficiency is due to the absence or reduced presence of protein C molecules, while in type II the deficiency is caused by the presence of an abnormal protein C molecule with strongly reduced functional activity.

This investigation was undertaken to determine the prevalence and degree of malnutrition among patients with chronic obstructive pulmonary disease and to determine if a relationship exists between nutritional assessment parameters and pulmonary function. Thirty-seven patients admitted for the treatment of chronic obstructive pulmonary disease to a respiratory care unit of a Veterans Administration facility were studied. Nutritional status was evaluated using anthropometric measurements, laboratory data and immunologic assay. Deficits in anthropometric measurements were frequent and severe in this group of patients. Furthermore, our data demonstrated that patients with a forced vital capacity

A kindred with a history of multiple thromboses was studied for coagulant abnormalities. A deficiency of serum antithrombin III was found in approximately half of the 13 family members by either coagulant or immunologic assay. No clear relationship between antithrombin III deficiency and a history of thrombosis was present. Platelet antithrombin assays were also studied in the same subjects. Ten of the 13 members were deficient. None of the remaining three had a history of thrombosis. On the basis of these findings, the hypothesis is proposed that in some cases familial hypercoagulability may be due to a platelet antithrombin deficiency and that the serum antithrombin III deficiency in some cases is a secondary rather than a primary effect.

The effect of L-asparaginase (L-asp) therapy on circulating antithrombin-III (AT-III) was monitored in three patients with acute lymphoblastic leukemia. Serial determination for AT-III by both a functional assay and an immunologic assay demonstrated a rapid decrease in serum AT-III levels, followed by a protracted recovery beyond the period of L-asp exposure. One of the three patients developed a reversible venous thrombosis of the arm. The mechanism of the L-asparaginase effect may be related to peripheral degradation of AT-III or to inhibition of production.

A comparison of functional and immunologic assays of antithrombin III was carried out in several groups of patients. The control group consisted of 120 male and female patients on medical and obstetrics–gynecology wards, ages 14 to 70 years. They were not receiving estrogen therapy or anticoagulant drugs and had no known disturbance of coagulation or thrombotic episode. The experimental groups consisted of 42 female patients, ages 14 to 32 years, who were receiving oral contraceptive therapy; ten postpartum patients; one patient who had disseminated intravascular coagulation; and seven patients with thromboembolic diseases. Additional coagulation studies were performed on all patients throughout the study. With the exception of those for women taking contraceptives, results of the functional and immunologic assays were generally consistent. The contraceptive group showed a difference between the two assays. The functional assay was low in approximately 55% of the cases, whereas the corresponding immunologic test disclosed normal concentrations of antithrombin III in all but 12% of those tested. The discrepancy between the two tests found in individuals taking contraceptive medication implies the presence of a substance that interferes with the functional assay but not the immunologic assay. Thus, even though the amount of protein, as detected immunologically, appears to be normal in patients taking contraceptives, there is, nonetheless, evidence of dysfunction in some of the patients, possibly related to blocking factors.

Current assay methods do not define the absolute concentrations of calcitonin in plasma of normal man. In our experience, the concentration was

A brief description of our experience with the immunoassay of insulin by the technic of Hales and Randle is given. Insulin values determined in twelve normal children and in seven cases of untreated diabetes mellitus in the fasting state and following a glucose load are presented. A newly diagnosed untreated child with diabetes mellitus had a low fasting insulin and gave very little response to test meal of glucose. Implications of these findings are discussed briefly.

The production of a lymphokine, the leukocyte-migration-inhibition factor (LIF), by peripheral blood lymphocytes in response to an in vitro challenge with bovine β-lactoglobulin was assayed in infants and children suspected of having allergy to cow's milk protein. of the patients studied, 24 had cow's milk allergy, 24 were normal control subjects, 18 had recovered from milk allergy, 10 were newborns, and 10 were babies suffering from acute gastroenteritis. All patients with milk allergy demonstrated significant LIF production in response to β-lactoglobulin (23.5% ± 6.4%). In the normal control subjects, LIF was 3.1% ± 4.3% (P < .0005). Only two of the 24 control subjects and two of the ten newborns had high-normal values bordering on the positive. None of the ten babies with acute gastroenteritis gave a positive response. Most of the children who had recovered from milk allergy and were ingesting cow's milk had negative assays. This cell-mediated immune assay is shown to be a reliable test for the diagnosis of sensitivity to milk protein in infants and children, and for determining dietary treatment and when this treatment can be safely terminated. In most cases, its use should eliminate the need for the potentially dangerous and ethically questionable provocation test, as well as the need for repeated intestinal biopsies.

A kindred with a history of multiple thromboses was studied for coagulant abnormalities. A deficiency of plasma antithrombin III was found in approximately half of the 13 family members by either coagulant or immunologic assay. No clear relationship between plasma antithrombin III deficiency and a history of thrombosis was present. Platelet antithrombin assays were studied in the same family. Ten of the 13 members were deficient. None of the three who was normal had a history of thrombosis. The plasma antithrombin III assays could be influenced by heparin or coumarin treatment. The same medications were without consistent effect on platelet antithrombin. On the basis of these findings, it is proposed that familial hypercoagulability in some cases may be due to a platelet antithrombin deficiency and that the plasma antithrombin III deficiency is a secondary effect.

Assays of urinary human chorionic gonadotropin (HCG) in normal and abnormal pregnancies performed by a hemagglutination inhibition method are presented. Antisera were produced in rabbits. An HCG preparation of pooled urine of pregnant women was used as a laboratory standard. 1st morning urine samples were obtained from a large group of patients mostly in aid of diagnosis of pregnancy. Patients with a variety of pathologic conditions also supplied specimens. There were a total of 1021 assays on 691 patients. It was possible to follow only 492 patients for 588 assays. There were 10 false positive and 2 false negative results for an overall accuracy of 98.0%. The mean level of HCG in normal pregnancies peaked at about 70,000 IU in the first trimester then fell to a constant level of 20,000 IU during the 2nd half of the pregnancy. The 95% confidence limits of the levels in normal pregnancy were from 10,000 to 350,000 IUD in the latter part of the first trimester and 2500-150,000 in the remainder. The levels of HCG in patients with clinical evidence of threatened abortion were determined. There were 86 such pregnancies, 47 of which had spontaneous abortion, while the remaining 39 went to term. The mean levels of the urinary HCG in the patients that aborted were consistently lower than those with normal pregnancies. Only during the period of 57-110 days after the last menstrual period were the values significant (P less than .001). 4 out of 6 patients with hydatidiform moles had titers of HCG greater than the normal range. HCG tests are also useful in following patients treated with chemotherapy for choriocarcinoma. The immunologic assay of HCG is a rapid, uncomplicated method of determining the level of HCG. It is of value in aiding the clinician in diagnosis, prognosis, and management of certain pathologic conditions of pregnancy.

Plasma and urinary prothrombin conncentration and plasma prothrombin activity were measured in a group of 17 patients with the nephrotic syndrome. An immunologic assay using a monospecific antibody against human prothrombin was employed in the measurement of prothrombin concentration in the plasma and urine. Prothrombin-deficient plasma was used as the substrate in the measurement of plasma prothrombin activity. A control group consisting of five normal volunteers was included for comparison. Both the activity and concentration of prothrombin were significantly lower in the nephrotic group as compared with the control group. Significant quantities of immunoreactive prothrombin were detected in the urine of the majority of nephrotic patients. This study has provided unequivocal evidence of urinary excretion and acquired deficiency of prothrombin in the nephrotic syndrome.

In a prospective study, 1412 neonates were screened for congenital CMV infection by detection of viruria during the first week of life; 31 (2.2%) proved to be infected. Rheumatoid factor (RF) was present in the cord sera of 7 of 18 (38%) infected and 0 of 155 uninfected infants. Likewise IgM was elevated (≥20 mg%) in 7 of 18 (38%) infected patients (77% correlation with the presence of RF), but was also increased in 5 of 155 (3.2%) controls. IgM-CMV antibodies (FA) were detected in cord sera of 14 of 16 (88%) infected neonates and surprisingly in 14 of 59 (23%) controls. The false positive reactions in the IgM-FA were unrelated to the presence of RF, IgM elevation or poor specificity of the IgM conjugate. Because of the time required for conventional isolation of CMV and the poor sensitivity and specificity of the immunologic assays it seemed desirable to develop a more convenient diagnostic assay. A rapid viral isolation method based on the expression of specific 24 hrs. nuclear fluorescence was developed and assessed. In 19 of 20 (95%) urine samples containing CMV the diagnosis was correctly made only one day after receiving the samples. The number of positive nucleiper field correlated with the infectivity established by tube titration. This rapid assay has a specificity and sensitivity equivalent to the conventional CMV isolation method and matches the rapidity of the immunologic assays.