Positive Propoxyphene Test Result for Drug-Free Serum or Plasma Obtained When Using the Roche Cobas c502 Urine Propoxyphene Screening Test

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S81-S81
Author(s):  
Geetha Jagannathan ◽  
Mark Curtis ◽  
Douglas Stickle
Keyword(s):  
Screening Test ◽  
Drugs Of Abuse ◽  
Positive Test ◽  
Test Results ◽  
Autopsy Case ◽  
Serum Samples ◽  
Drug Free ◽  
Positive Results ◽  
Test Result ◽  
Roche Cobas

Abstract Introduction During a recent autopsy case, we were asked to investigate possible surreptitious inpatient use of drugs of abuse (DOA). As serum was the only sample type available for this subject, we initially ran serum samples on our urine drugs of abuse (DOAU) assays. Results were unexpectedly positive for propoxyphene (PPX). We immediately determined, however, that all plasma or serum samples, selected randomly from the hospital laboratory as presumed-negative controls, produced PPX-positive test results on the urine PPX assay. We report our investigation of this finding. Methods The PPX urine assay (Roche Cobas c502, Indianapolis, IN) is a semiquantitative screening test based on kinetic interaction of microparticles in solution (KIMS), with a cutoff concentration of 300 ng/mL. The assay was conducted according to manufacturer’s instructions, other than the substitution of plasma for urine as described below. Plasma or urine samples were obtained from to-be-discarded samples residual from routine testing in the hospital laboratory. Results Pooled plasma required a 1:4 dilution with drug-free urine to produce a PPX-negative test result. Bovine serum albumin (7 g/dL), mimicking total protein of plasma, produced a PPX-negative test result. Pretreatment of plasma using heterophilic antibody blocking reagent (Scantibodies Laboratory, Santee, CA) did not alter the PPX-positive test result. However, pretreatment of plasma by polyethylene glycol (PEG) to precipitate immunoglobulins altered the test result to PPX negative. PEG pretreatment did not alter PPX-positive results for PPX-spiked urine. Conclusions An autopsy case produced an incidental finding of false-positive test results for plasma tested on the Roche urine PPX assay. Based on PEG pretreatment data, it appears that some common component of immunoglobulins in plasma produces a positive interference in this assay. In principle, rare circumstances of severe renal dysfunction to produce plasma-like urine could potentially lead to false-positive results with the Roche urine PPX screening test.

scholarly journals A diagnostic test for heparin-induced thrombocytopenia

Blood ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 27-30 ◽  
Author(s):  
D Sheridan ◽  
C Carter ◽  
JG Kelton
Keyword(s):  
High Specificity ◽  
Heparin Therapy ◽  
Positive Test ◽  
Test Results ◽  
Specific Test ◽  
Heparin Induced Thrombocytopenia ◽  
Platelet Release ◽  
High Concentrations ◽  
Low Sensitivity ◽  
Test Result

Heparin-induced thrombocytopenia can be a serious and difficult-to- diagnose complication of heparin therapy. Serum from patients with heparin-induced thrombocytopenia can cause heparin-dependent platelet aggregation, but the low sensitivity and specificity of this test limit its clinical usefulness. In this report we describe an assay for heparin-induced thrombocytopenia that is both sensitive and specific. The improvement in the assay was accomplished by measuring platelet release instead of aggregation and by measuring platelet release at two heparin concentrations. The rationale for the use of two heparin concentrations was that sera from patients with heparin-induced thrombocytopenia caused release at therapeutic but not at high concentrations of heparin. Twenty-eight sera samples from patients suspected of having heparin-induced thrombocytopenia and 573 controls were coded and tested in the assay. The patients with possible heparin- induced thrombocytopenia were ranked according to the likelihood of having this disorder by using prospectively defined criteria. The test had a high specificity (99%); only one of 573 controls showed a positive result. The test was also very sensitive, and the likelihood of a positive test result was directly correlated with the clinical likelihood of the patient having heparin-induced thrombocytopenia. Six of six patients with definitive heparin-induced thrombocytopenia had positive test results, whereas zero of four patients in whom the diagnosis was unlikely had positive test results. The two-point test for heparin-induced thrombocytopenia represents a sensitive and specific test for this disorder. This test may be useful not only in confirming the diagnosis of this disorder but also may provide information about its pathogenesis.

Investigation of interference by nonsteroidal anti-inflammatory drugs in urine tests for abused drugs

1990 ◽  
Vol 36 (4) ◽  
pp. 602-606 ◽  
Author(s):  
D E Rollins ◽  
T A Jennison ◽  
G Jones
Keyword(s):  
False Positive ◽  
Drugs Of Abuse ◽  
Fluorescence Polarization Immunoassay ◽  
Dosage Regimens ◽  
Chronic Ingestion ◽  
Inflammatory Drugs ◽  
Anti Inflammatory ◽  
Abused Drugs ◽  
Positive Results ◽  
Test Result

Abstract Anecdotal and uncontrolled studies have suggested that nonsteroidal anti-inflammatory drugs produce false-positive results in immunoassay urine tests for some drugs of abuse. This study was performed in 60 volunteers who took ibuprofen as either a single 400-mg dose, or 200 mg three times a day, or 400 mg three times a day, and in 42 patients taking ibuprofen, naproxyn, or fenoprofen in therapeutic regimens for more than 30 days. Of the 510 urines collected from 102 individuals during these dosage regimens, two gave false-positive tests for cannabinoid by enzyme-mediated immunoassay (EMIA), one after 1200 mg of ibuprofen in three divided doses for one day and one in a patient taking naproxyn on a chronic basis; none was falsely positive for benzodiazepines. Two urines were false-positive for barbiturates by fluorescence polarization immunoassay (FPIA), one in a patient taking ibuprofen and one in a patient taking naproxyn. These data, collected prospectively, demonstrate the small likelihood of a false-positive immunoassay test result for cannabinoids, benzodiazepines, or barbiturates after the acute or chronic ingestion of ibuprofen, or after the chronic ingestion of naproxyn or fenoprofen.

scholarly journals HIV post-test practices: an online survey examining perceived delivery of HIV test results, post-test discussion and referral in healthcare settings across the WHO European Region

Sexual Health ◽  
2016 ◽  
Vol 13 (3) ◽  
pp. 205 ◽  
Author(s):  
Stephen Bell ◽  
Jordi Casabona ◽  
Nino Tsereteli ◽  
Dorthe Raben ◽  
John de Wit
Keyword(s):  
Hiv Testing ◽  
Positive Test ◽  
European Region ◽  
Hiv Positive ◽  
Test Results ◽  
Negative Test ◽  
Hiv Test ◽  
Post Test ◽  
Test Result ◽  
Hiv Negative

Background The aim of this study was to assess perceptions of health professionals involved in HIV testing policy and practice in national settings across the WHO European Region regarding the delivery of HIV test results, post-test discussion and referral to specialist HIV services as recommended in authoritative guidelines. Methods: An online self-report survey was completed by a convenience sample of 338 respondents (response rate 34.1%) from 55 countries. Respondents worked with non-government organisations (49.4%), health services (32.8%), non-health service government agencies (6.2%) or other organisations (11.5%; e.g. prisons, education and research, international development). Results: Experts’ perceptions indicate that delivery of HIV-positive test results and related post-test discussion in their country generally corresponded to recommendations. However, results pointed to a significant gap perceived by experts between recommendations and the practice of delivering HIV-negative test results. Fewer respondents thought that suitable time is taken to deliver a negative HIV-test result (54.1%) than a positive result (73.1%). Also, fewer respondents thought there was a procedure for referral to specialist treatment, care and support services for people receiving a HIV-negative test result (34.9%) than for people receiving an HIV-positive test result (86.2%). Experts also reported low perceived use of communication technologies (i.e. telephone, email, text messaging, a secure website) for delivering HIV test results. Conclusions: This expert survey offers new insight into perceived HIV post-test practices in almost all national settings across the WHO European Region. The findings provide valuable guidance for future HIV testing guidelines for the WHO European Region.

DETECTION OF SOLUBLE FIBRIN MONOMER COMPLEXES - COMPARISON OF A HAEMAGGLUTINATION ASSAY WITH THE ETHANOL GELATION TEST

1987 ◽  
Author(s):  
G Oehler ◽  
H Klaus ◽  
E Spanuth ◽  
K E Stötzer
Keyword(s):  
Degradation Products ◽  
Positive Test ◽  
Test Results ◽  
Soluble Fibrin ◽  
Fibrin Degradation Products ◽  
Fibrin Monomer ◽  
At Iii ◽  
Positive Results ◽  
Fibrin Monomers ◽  
Gelation Test

Hypercoagulability and disseminated intravascularcoagulation (DIC) are characterized by the presenceof circulating fibrin monomer complexes in plasma.In342 patients with possible DIC fibrin monomers, fibrinogen, reptilase time, antithrombin III and othercoagulation parameters were determined at frequent intervals.Testing of soluble fibrin monomer complexeswas performed using a sensitive and reliable haemagglut- ination assay, with red cells sensitized by fibrin monomers (FM-Test) and the ethanol gelation test(EGT). Method comparison regarding the influence offibrinogen levels and fibrin degradation products shows that high fibrinogen levels lead to false positive results with EGT. The same effect is observed forfibrin degradation products and EGT whereas no influence of fibrinogen level and fibrin degradation products on the FM-Test occurs.It could be shown that with normal fibrinogen concentrations (200-400 mg/dl) the positive test results by FMT and EGT are comparable, whereas with fibrinogen concentrations below 200 mg/dl the number of positive results obtained with the EGT amounted to half the number given by FMT. In the case of fibrinogen concentrations above 400 mg/dl, positive results obtained with EGT were 3.3 times higher than FMT. Nearlyidentical results were obtained by comparing the influence of degradation products. In case of high degradation product concentrations, EGT gives 4.5 timesmore positive results than FMT.Further we compared the number of positive test results obtained by the FMT with the level of AT III because it is wellknown that the AT IIIHevel decreases caused by proteolytic activity generated in DIC.In this study it could be shown that fibrin monomer increases in parallel with the decrease of AT III. Thiseffect does not occur with fibrin degradation products.

EFFECT OF FEEDING ON SCREENING FOR PKU IN INFANTS

PEDIATRICS ◽  
1973 ◽  
Vol 51 (3) ◽  
pp. 531-538
Author(s):  
Virginia K. Dontanville ◽  
George C. Cunningham
Keyword(s):  
Screening Test ◽  
Gradual Increase ◽  
Serum Levels ◽  
Test Results ◽  
Rapid Rise ◽  
Repeat Testing ◽  
Early Testing ◽  
The Mean ◽  
Effect Of Feeding ◽  
Test Result

No relationship between the phenylalanine content of the feedings prior to the PKU screening test and a positive test result (≥4 mg/100 ml) could be demonstrated in a study of hospital records of 68 phenylketonuric, 14 atypical, and 26 hyperphenylalaninemic infants. The mean age at testing was 62.8 hours. The median intake before testing was 383 mg of phenylalanine with a range of 0 in five cases to over 3,000 mg for two late tested infants. One quarter of the infants with positive tests had ingested less than 200 mg of phenylalanine, while only one of the 11 with negative tests had less than 200 mg. The "missed" cases were represented at each intake interval, and intakes ranged from 174 to 1,326 mg phenylalanine. Screening test results ranged from 1 to 40 mg/100 ml (mean of 10.0) with wide variation at all intervals of phenylalanine intake. There was a gradual increase in mean levels from 7.1 mg/100 ml in the group with least intake to 13.0 for those having the most. This increase was attributable mainly to the PKUs whose mean levels were higher than those of the atypicals and hypers at all intake intervals, and went much higher with increased intake. Serial tests on 20 infants who had repeat testing in the first few days of life when feeding was documented demonstrated the rapid rise in serum levels in PKUs as feeding continued in contrast to the atypicals and hypers who showed only slight increases during this period. The authors conclude there is no evidence that missed cases are significantly related to feeding protein or early testing in routine PKU screening of the newborn infant.

Comparison of the Milk Quality Gauge (MQG) With the Wisconsin Mastitis Test (WMT)1

1976 ◽  
Vol 39 (6) ◽  
pp. 394-396
Author(s):  
R. KEVIN CHUMNEY ◽  
DICK H. KLEYN
Keyword(s):  
Screening Test ◽  
Milk Quality ◽  
Positive Test ◽  
Column Height ◽  
Test Results ◽  
Filtration Time ◽  
Milk Samples ◽  
Herd Milk ◽  
Test Disk ◽  
High Sediment

The Milk Quality Gauge (MQG), a cowside, screening test for abnormal milk, is based on observing the rate of flow of warm milk under vacuum through a dense test disk. The MQG, as applied to individual cow and herd milk samples has been evaluated in this study, a filtration time of 15 sec or more being considered a positive test. Results were compared with those obtained by the WMT in which a column height of 20 mm or more was considered a positive test. Of 364 herd samples tested, 97 were positive to MQG and nine to WMT, eight of these latter nine samples being positive for both tests. Of 181 individual cow samples tested. 75 were positive to MQG and 22 to WMT. all of these latter 22 samples being positive for both tests. High sediment content was considered to be a factor contributing to the large number of positive MQG samples. Also, many of the herd milk samples were old, a factor which probably influenced the WMT results obtained on them. When a yellow material on the disk was used as a criterion for a positive test, the MQG was found to agree with the WMT in 16 of the 22 positive WMT results and 175 of the 181 total, individual cow samples.

scholarly journals Centrifugation may eliminate false-positive leucocyte esterase strip test results caused by inflammatory arthritis in the diagnosis of knee infection

2020 ◽  
Vol 9 (5) ◽  
pp. 236-241
Author(s):  
Rui Li ◽  
Chi Wang ◽  
Xiao-Jian Ji ◽  
Qing-Yuan Zheng ◽  
Xiang Li ◽  
...  
Keyword(s):  
False Positive ◽  
Inflammatory Arthritis ◽  
Test Results ◽  
Knee Infection ◽  
Negative Results ◽  
Before And After ◽  
Strip Test ◽  
Positive Results ◽  
Test Result ◽  
Colour Chart

Aims The purpose of this study was to validate our hypothesis that centrifugation may eliminate false-positive leucocyte esterase (LE) strip test results caused by autoimmune diseases in the diagnosis of knee infection. Methods Between January 2016 and May 2019, 83 cases, including 33 cases of septic arthritis and 50 cases of aseptic arthritis, were enrolled in this study. To further validate our hypothesis, another 34 cases of inflammatory arthritis from the Department of Rheumatology of our institution were also included. After aspiration, one drop of synovial fluid was applied to LE strips before and after centrifugation. The results were recorded after approximately three minutes according to the different colour grades on the colour chart. The differences of LE results between each cohort were analyzed. Results Before centrifugation, 46% (23/50) of the LE strip tests in the aseptic arthritis group were false-positives. Most of the false-positive results were due to inflammatory arthritis; after centrifugation, 78.3% (18/23) of the tests yielded negative results. Similar results were observed in cases from the Department of Rheumatology. The sensitivity of the centrifuged LE strip test was 0.818 (0.639 to 0.924), which is still an acceptable level compared with the uncentrifuged results, which yielded a sensitivity of 0.909 (0.745 to 0.976). However, the specificity was increased from 0.540 (0.395 to 0.679) to 0.900 (0.774 to 0.963) after centrifugation. Conclusion Although inflammatory arthritis can yield a false-positive LE strip test result in the diagnosis of knee infection, centrifugation may eliminate these false-positive results. Cite this article: Bone Joint Res. 2020;9(5):236–241.

scholarly journals A diagnostic test for heparin-induced thrombocytopenia

Blood ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 27-30 ◽  
Author(s):  
D Sheridan ◽  
C Carter ◽  
JG Kelton
Keyword(s):  
High Specificity ◽  
Heparin Therapy ◽  
Positive Test ◽  
Test Results ◽  
Specific Test ◽  
Heparin Induced Thrombocytopenia ◽  
Platelet Release ◽  
High Concentrations ◽  
Low Sensitivity ◽  
Test Result

Abstract Heparin-induced thrombocytopenia can be a serious and difficult-to- diagnose complication of heparin therapy. Serum from patients with heparin-induced thrombocytopenia can cause heparin-dependent platelet aggregation, but the low sensitivity and specificity of this test limit its clinical usefulness. In this report we describe an assay for heparin-induced thrombocytopenia that is both sensitive and specific. The improvement in the assay was accomplished by measuring platelet release instead of aggregation and by measuring platelet release at two heparin concentrations. The rationale for the use of two heparin concentrations was that sera from patients with heparin-induced thrombocytopenia caused release at therapeutic but not at high concentrations of heparin. Twenty-eight sera samples from patients suspected of having heparin-induced thrombocytopenia and 573 controls were coded and tested in the assay. The patients with possible heparin- induced thrombocytopenia were ranked according to the likelihood of having this disorder by using prospectively defined criteria. The test had a high specificity (99%); only one of 573 controls showed a positive result. The test was also very sensitive, and the likelihood of a positive test result was directly correlated with the clinical likelihood of the patient having heparin-induced thrombocytopenia. Six of six patients with definitive heparin-induced thrombocytopenia had positive test results, whereas zero of four patients in whom the diagnosis was unlikely had positive test results. The two-point test for heparin-induced thrombocytopenia represents a sensitive and specific test for this disorder. This test may be useful not only in confirming the diagnosis of this disorder but also may provide information about its pathogenesis.

Impact of BRCA1/BRCA2 Mutation Testing on Psychologic Distress in a Clinic-Based Sample

2002 ◽  
Vol 20 (2) ◽  
pp. 514-520 ◽  
Author(s):  
Marc D. Schwartz ◽  
Beth N. Peshkin ◽  
Chanita Hughes ◽  
David Main ◽  
Claudine Isaacs ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Perceived Risk ◽  
Brca2 Mutation ◽  
Positive Test ◽  
Test Results ◽  
Brca1 And Brca2 ◽  
Negative Test ◽  
Psychologic Distress ◽  
The Impact ◽  
Test Result

PURPOSE: Despite the increasingly widespread availability of BRCA1 and BRCA2 genetic testing, little is known about the psychologic impact of such testing in the clinical setting. The objective of this study was to examine the long-term psychologic impact of receiving BRCA1/2 test results within a clinic-based testing program. PATIENTS AND METHODS: The participants were 279 high-risk women who underwent genetic counseling and testing for alterations in the BRCA1/2 genes. At baseline (before genetic testing) and at 6 months after the disclosure of mutation status, we measured perceived risk for breast and ovarian cancer, cancer-specific distress, and general distress. We examined the impact of the test result on each of these outcomes at the 6-month follow-up. Analyses were conducted separately for probands and their relatives who were unaffected with cancer. RESULTS: We found no effect of test result among affected probands. Among unaffected relatives, we found that participants who received definitive negative test results exhibited significant reductions in perceived risk and distress compared with participants who received positive test results. Importantly, relatives who received positive test results did not exhibit increased distress or perceived risk. CONCLUSION: These results suggest that clinic-based BRCA1/2 testing can lead to psychologic benefits for individuals who receive negative test results. At 6 months after disclosure, those who receive positive or uninformative test results do not exhibit increased psychologic distress or perceived risk.

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