scholarly journals Direct comparison of performance characteristics of two immunoassays for bone isoform of alkaline phosphatase in serum

1997 ◽  
Vol 43 (11) ◽  
pp. 2052-2057 ◽  
Author(s):  
Christopher P Price ◽  
Thomas P Milligan ◽  
Claude Darte
Keyword(s):  
Alkaline Phosphatase ◽  
Reference Range ◽  
Cross Reactivity ◽  
Performance Characteristics ◽  
Paget Disease ◽  
Specific Assay ◽  
Comparison Of Results ◽  
Immunometric Assay ◽  
Detailed Evaluation ◽  
Electrophoretic Procedure

Abstract A clinical need exists for a sensitive and specific assay for the quantitation of the bone isoform of alkaline phosphatase in serum. The majority of methods do not meet this requirement; however, the recent development of immunoassays for this isoform may provide a solution. In a detailed evaluation of two immunoassays, we found a degree of imprecision that enables the discrimination of changes within the reference range. The cross-reactivity of the liver isoform was found to be between 7.1% and 12.7% when two different methods of assessment were used. The comparison of results with an electrophoretic procedure showed that the immunocapture method recovered less of the bone isoform in samples from children than in samples from patients with Paget disease; no such difference was found with the immunometric method. This suggests that the immunocapture antibody may discriminate between different bone isoforms in children whereas the immunometric assay does not.

scholarly journals Mass versus Activity: Validation of an Immunometric Assay for Bone Alkaline Phosphatase in Serum

1995 ◽  
Vol 32 (4) ◽  
pp. 405-412 ◽  
Author(s):  
C P Price ◽  
C A Mitchell ◽  
J Moriarty ◽  
M Gray ◽  
K Noonan
Keyword(s):  
Renal Failure ◽  
Alkaline Phosphatase ◽  
Reference Range ◽  
Paget’S Disease ◽  
Bone Alkaline Phosphatase ◽  
Paget's Disease ◽  
Cross Reactivity ◽  
Age Group ◽  
Immunometric Assay ◽  
Activity Measurements

A detailed investigation of the performance of an immunometric assay for the quantitation of bone alkaline phosphatase (ALP) in serum showed that precision of this assay was similar to that of lectin precipitation and electrophoretic methods. Relationships for mass and activity measurements of the bone isoform using samples from children and patients with Paget's disease were similar for lectin and electrophoretic methods. Purified liver enzyme showed 100% cross reactivity in the immunometric assay. However, comparison of the slopes between bone ALP mass and total ALP activity using only samples with predominantly liver or bone isoforms showed that the cross reactivity of the liver isoform in serum was 18·3%. Experiments in which increasing amounts of a sample containing 90% of liver isoform adding to a serum sample from a patient with Paget's disease showed a cross reactivity of 16·5%. The reference range for bone ALP mass was 7–28 μg/L for men ( n = 77) and 5–20 μg/L for women ( n = 110) in the age group 20–50 years. In women over 50 years bone ALP was 28% higher. Increased bone ALP mass was also demonstrated in patients with Paget's disease ( n = 59), liver disease ( n = 95), chronic renal failure ( n = 41) and hyperthyroidism ( n = 17).

Abstract #208 Paget Disease of Bone with Normal Alkaline Phosphatase

2019 ◽  
Vol 25 ◽  
pp. 67
Author(s):  
Jinetsy Rivera-Ortiz ◽  
Milliette Alvarado-Santiago ◽  
Margarita Ramirez-Vick ◽  
Naomi Collazo-Gutierrez ◽  
Loida Gonzalez-Rodriguez
Keyword(s):  
Alkaline Phosphatase ◽  
Paget Disease Of Bone ◽  
Paget Disease

scholarly journals 753. Performance Characteristics of Diagnostic Assays in Blastomycosis

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S424-S424
Author(s):  
Timothy O’Dowd ◽  
Jack McHugh ◽  
Nancy Wengenack ◽  
Elitza Theel ◽  
Paschalis Vergidis
Keyword(s):  
Granulomatous Inflammation ◽  
Cross Reactivity ◽  
Performance Characteristics ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fungal Culture ◽  
Noninvasive Test ◽  
Serum Antigen ◽  
Urine Antigen ◽  
Antigen Tests ◽  
Urine And Serum

Abstract Background Blastomycosis has historically been a difficult diagnosis to establish, often initially misdiagnosed as bacterial pneumonia. Serologic assays and polymerase chain reaction (PCR) tests are available, but their performance is not well defined. The objective of this study was to characterize their performance. Methods Subjects were identified via chart review of patients diagnosed with blastomycosis from 2005 to 2020. A definitive diagnosis was based on fungal culture, histopathology, or cytology. Performance characteristics of the Blastomyces antibody enzyme linked immunosorbent assay (ELISA), immunodiffusion (ID), complement fixation (CF), urine and serum antigen ELISAs, and PCR were evaluated in patients with confirmed blastomycosis. Data on patient demographics, location of disease, and mortality was also collected. Results We identified 193 patients with blastomycosis. The mean age was 51.8 years (range, 11-84) and 73.6% of patients were male. 42.5% resided in Minnesota, 18.1% in Wisconsin, and 12.9% in Iowa. Diagnosis was based on culture in 142 (73.2%) or histopathology/cytology in 67 (34.7%) patients. Granulomatous inflammation was present in 73.1% (38/52) while 21.2% (41/193) had evidence of extrapulmonary dissemination. The antibody, ID, and CF assays were positive in 43.5% (37/85), 35.1% (33/94) and 20.5% (8/39) of patients, respectively. Sensitivity of Blastomyces PCR was 40% (4/10) in sputum and 75% (21/28) in bronchoalveolar lavage (BAL) fluid. Blastomyces urine and serum antigen tests were positive in 68% (34/50) and 50% (9/18) of cases, respectively, while the urine antigen was positive in 63.6% (7/11) of disseminated cases. Patients had a positive Histoplasma urine antigen test in 54.1% (20/37) and Aspergillus galactomannan in BAL in 34.8% (8/23) of cases. Serum beta-D-glucan test was positive in 16.7% (2/12). 90-day mortality was 21/193 (10.9%) and median time from diagnosis to death was 18 days. Conclusion In this cohort, Blastomyces urine antigen was the most sensitive noninvasive test, with similar performance in pulmonary and disseminated disease. However, its utility is limited by poor specificity due to cross-reactivity. Blastomyces PCR from BAL fluid demonstrated the highest sensitivity. Blastomyces antibody, ID, and CF had poor sensitivity. Disclosures All Authors: No reported disclosures

An Evaluation of the Greiner Selective Analyzer and its Role in the Clinical Laboratory

1975 ◽  
Vol 12 (1-6) ◽  
pp. 182-191 ◽  
Author(s):  
Andrew G. Skinner ◽  
Peter Wilding
Keyword(s):  
Alkaline Phosphatase ◽  
Serum Creatinine ◽  
Total Protein ◽  
Total Bilirubin ◽  
Clinical Laboratory ◽  
Comparison Of Results ◽  
Operation Temperature ◽  
Accuracy And Precision ◽  
Analytical Range

The Greiner Selective Analyzer (GSA II) was evaluated over a period of six months. The evaluation assessed the reliability, accuracy, and precision of the analyser for six determinations. The methods evaluated were for glucose, urea, creatinine, total protein, total bilirubin, and alkaline phosphatase. Comparison of results was also made with those obtained for the same specimens using the Technicon SMA 12/60 Analyzer. Correlation and comparison of results indicate that the Greiner Selective Analyzer performed better for three of the methods but worse for serum creatinine determination. The role of the analyser as a routine tool in the clinical laboratory was also evaluated during analyses of approximately 900 patient specimens. Other features evaluated were analytical range of the six methods under study, the economics of operation, temperature control, and electrical and mechanical safety.

Immunoradiometric method and electrophoretic system compared for quantifying bone alkaline phosphatase in serum

1995 ◽  
Vol 41 (6) ◽  
pp. 853-857 ◽  
Author(s):  
V O Van Hoof ◽  
M Martin ◽  
P Blockx ◽  
A Prove ◽  
A Van Oosterom ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Malignant Disease ◽  
Screening Method ◽  
Bone Alkaline Phosphatase ◽  
Cross Reactivity ◽  
Osteoblastic Activity ◽  
Alp Activity ◽  
Agarose Electrophoresis ◽  
End Stage ◽  
Rule Out

Abstract Agarose electrophoresis (Isopal, Beckman) and an immunoradiometric assay (IRMA) involving specific monoclonal antibodies (Ostase, Hybritech), two methods for the quantification of serum bone alkaline phosphatase (ALP, EC 3.1.3.1), a marker of osteoblastic activity, were compared in 293 patients: 79 with end-stage renal failure treated with hemodialysis and 214 with malignant disease. Overall correlation between the two methods was good (r = 0.92), except (a) for low values of bone ALP and (b) in some samples with high total liver ALP activity--both due to considerable cross-reactivity of the anti-bone ALP antibodies of the Ostase kit with liver ALP. This interference was not constant and was not evenly distributed across all concentrations of bone ALP. Low bone ALP determined with the IRMA (< or = 5 micrograms/L) was confirmed by electrophoresis (< or = 21 U/L), but bone ALP activity determined by electrophoresis to be low (< or = 21 U/L) was not correlated with the IRMA results. After standardizing our results by computing z-values for bone ALP, delta z (= zOstase - zIsopal) was significantly correlated with liver ALP activity (r = 0.73, P < 0.0001). We conclude that the IRMA for quantifying bone ALP is acceptable as a screening method. However, when high values for bone ALP are found with the Ostase method, confirmation by electrophoresis remains mandatory to rule out cross-reactivity with high amounts of liver ALP. For detecting low bone ALP activities, electrophoresis remains the method of choice.

Sensitive fluorometry of heat-stable alkaline phosphatase (Regan enzyme) activity in serum from smokers and nonsmokers.

1983 ◽  
Vol 29 (2) ◽  
pp. 260-263 ◽  
Author(s):  
W C Maslow ◽  
H A Muensch ◽  
F Azama ◽  
A S Schneider
Keyword(s):  
Alkaline Phosphatase ◽  
Normal Limit ◽  
Heat Stability ◽  
Cross Reactivity ◽  
Fluorogenic Substrate ◽  
Normal Range ◽  
Heat Stable ◽  
Normal Individuals ◽  
Naphthoic Acid ◽  
The Mean

Abstract We developed a simple, sensitive enzymatic assay involving the fluorogenic substrate naphthol AS-MX phosphate [(3-hydroxy-2-naphthoic acid 2,4-dimethylanilide) phosphate] to measure heat-stable alkaline phosphatase (EC 3.1.3.1), the Regan isoenzyme, in human serum. The day-to-day CV was 5.7% for a serum activity of 0.080 arbitrary units/L. Measurable amounts of enzyme were detected in most normal individuals. The mean for 51 nonsmokers was 0.068 (SD 0.037) arb. units/L; for 25 smokers it was 0.440 (SD 0.360) arb. units/L. Activity of this isoenzyme in smokers was as much as 10-fold the upper normal limit for nonsmokers. Activation of this tumor marker by smoking has not received attention hitherto. We conclude that a truly normal range can only be established among nonsmokers. The isoenzymes in smokers, nonsmokers, and pregnant women were similar in their heat stability, immunologic cross reactivity, and inhibition by L-phenylalanine.

scholarly journals Immunoadsorption assay for bone alkaline phosphatase compared with wheat germ agglutinin precipitation assay in serum from (pre)pubertal girls

1996 ◽  
Vol 42 (12) ◽  
pp. 1970-1974 ◽  
Author(s):  
A A Bouman ◽  
C M de Ridder ◽  
J H Nijhof ◽  
J C Netelenbos ◽  
H A Delemarre-vd Waal
Keyword(s):  
Alkaline Phosphatase ◽  
Correlation Coefficient ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Bone Alkaline Phosphatase ◽  
Cross Reactivity ◽  
Reference Ranges ◽  
Correlation Studies ◽  
Deming Regression ◽  
The Mean

Abstract The performance characteristics of two bone alkaline phosphatase (ALP; EC 3.1.3.1) assays, a wheat germ agglutinin (WGA) precipitation assay and a new immunoadsorption assay (IAA), were compared. The within- and between-run imprecision of the IAA (3.6-4.2% and 3.6-7.7%) was comparable with that of the WGA assay. The mean cross-reactivity with liver ALP appeared to be 4% in the WGA assay and 11% in the IAA. The reference ranges in a group of 155 healthy Caucasian (pre)pubertal schoolgirls were: 149-401 U/L (total ALP, 30 degrees C), 105-349 U/L (bone ALP, 30 degrees C, WGA assay), and 58-205 U/L (bone ALP, 25 degrees C, IAA). Comparison of the WGA assay (x) with the IAA (y) demonstrated a correlation coefficient of 0.95 [Deming regression equation: y = (0.56 +/- 0.01)x + (2.0 +/- 1.5); Sy[symbol: see text]x = 5.3 U/L]. Correlation studies of the WGA assay and the IAA results with total ALP demonstrated r = 0.98 and 0.96, respectively.

Amplified Enzyme-Linked Immunoassay of Human Proinsulin in Serum (Detection Limit: 0.1 pmol/L)

1992 ◽  
Vol 38 (2) ◽  
pp. 227-232 ◽  
Author(s):  
F J Dhahir ◽  
D B Cook ◽  
C H Self
Keyword(s):  
Monoclonal Antibody ◽  
Alkaline Phosphatase ◽  
Cross Reactivity ◽  
C Peptide ◽  
Human Proinsulin ◽  
Microtiter Plates ◽  
Enzyme Amplification ◽  
Fold Excess ◽  
Amplification Procedure ◽  
Serum Detection

Abstract We describe an amplified enzyme-linked immunoassay of human proinsulin in serum that detects intact proinsulin and both the 32/33 and 65/66 split forms. The method uses the IgG fraction of a polyclonal antibody raised in a guinea pig against intact proinsulin, which we used to coat plastic microtiter plates. A sandwich was formed with proinsulin by using a monoclonal antibody against C-peptide labeled with alkaline phosphatase. We quantified the reaction by using the enzyme amplification procedure, which detected as little intact proinsulin as 0.1 pmol/L. We found no cross-reactivity with C-peptide in the assay, and decreased recovery attributable to the presence of insulin could be demonstrated only with a 30-fold excess of this hormone over proinsulin.

Placental alkaline phosphatase as a tumor marker for primary intracranial germinoma

1988 ◽  
Vol 68 (5) ◽  
pp. 710-720 ◽  
Author(s):  
Jun Shinoda ◽  
Hiromu Yamada ◽  
Noboru Sakai ◽  
Takashi Ando ◽  
Toshifumi Hirata ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Tumor Marker ◽  
Cross Reactivity ◽  
Cyst Fluid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Placental Alkaline Phosphatase ◽  
Intestinal Alkaline Phosphatase ◽  
Content Type ◽  
Intracranial Germinoma ◽  
Very High

✓ A sensitive enzyme-linked immunosorbent assay (ELISA) was used in a retrospective study of placental alkaline phosphatase (PLAP) levels in serum, cerebrospinal fluid (CSF), and intratumoral cyst fluid in primary intracranial germinoma. The ELISA showed no cross-reactivity with intestinal alkaline phosphatase except in very high concentrations, after samples had been heat-treated. Three patients with germinoma were studied for serum PLAP levels and in all the levels were elevated (3.78, 0.52, and 2.11 IU/liter). Two of the germinoma patients were studied for PLAP levels in the CSF, and both had elevated levels (0.83 and 9.83 IU/liter). The intratumoral cyst fluid in one case of germinoma was tested for PLAP and the level was found to be very high (603 IU/liter). These PLAP levels decreased concomitantly with the reduction in tumor size during irradiation. Serum PLAP levels were measured in 40 control adult male individuals and in the CSF of 20 nonpregnant patients with subarachnoid hemorrhage. The upper normal limits were 0.20 and 0.11 IU/liter in the serum and the CSF, respectively. All PLAP levels measured in the serum of patients with various brain tumors were 0.18 IU/liter or less. This study strongly suggests that PLAP is a clinically useful tumor marker for primary intracranial germinoma.

scholarly journals Evaluation of the Digene Hybrid Capture II CT-ID Test for Detection of Chlamydia trachomatis in Endocervical Specimens

1999 ◽  
Vol 37 (5) ◽  
pp. 1579-1581 ◽  
Author(s):  
Jennifer L. Girdner ◽  
Allison P. Cullen ◽  
Teresa G. Salama ◽  
Ling He ◽  
Attila Lorincz ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Chlamydia Trachomatis ◽  
Signal Amplification ◽  
Test System ◽  
Performance Characteristics ◽  
Hybrid Capture ◽  
Molecular Systems ◽  
Specific Assay ◽  
Highly Sensitive ◽  
Silver Spring

The performance characteristics of the new signal amplification-based Hybrid Capture (HC) II CT-ID test system (Digene, Silver Spring, Md.) with endocervical specimens were compared to those of tissue culture and PCR (AMPLICOR CT PCR; Roche Molecular Systems, Branchburg, N.J.) for detection of Chlamydia trachomatis in 587 women. HC II CT-ID identified 62 of 65 confirmed C. trachomatis-positive patients (sensitivity of 95.4%) and was negative for 517 of 522 patients who were negative by culture and PCR (specificity of 99.0%). Twelve of the 65 confirmed positive patients were negative by culture but were identified by both HC II CT-ID and PCR (sensitivity of culture was 81.5% [P < 0.01]). In comparison, PCR detected 59 of 65 positive specimens (sensitivity of 90.8%) and had a specificity of 99.6% (520 of 522). These results demonstrate that the Digene HC II CT-ID test is a highly sensitive and specific assay for the detection ofC. trachomatis infection in endocervical specimens.

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