scholarly journals P.006 Neural antibody testing for autoimmune encephalitis: A Canadian single-centre experience

2021 ◽  
Vol 48 (s3) ◽  
pp. S21-S21
Author(s):  
A Mirian ◽  
S McFadden ◽  
P Edmond ◽  
V Bhayana ◽  
L Yang ◽  
...  
Keyword(s):  
False Positive ◽  
Clinical Presentation ◽  
Clinical Phenotype ◽  
Autoimmune Encephalitis ◽  
Antibody Testing ◽  
Single Centre ◽  
Clinical Sensitivity ◽  
Single Centre Experience ◽  
One Year ◽  
Positive Results

Background: We reviewed our autoimmune encephalitis neural antibody testing using brain tissue indirect immunofluorescence (TIIF) and cell-based assays (CBAs) after one year. Methods: Samples were tested from March 2019–March 2020 by TIIF and CBA for anti-NMDAR, LGI1, CASPR2, AMPAR, GABA(B)R, DPPX, IgLON5 and GAD65. Weakly positive or positive CBA, with or without corresponding TIIF positivity, was reported positive. Clinical questionnaires were submitted for clinical-serological correlation. Patients with a compatible clinical phenotype and no more likely alternative diagnosis were classified as true-positives, while all others were flagged as possible false-positives. Results: Twenty of 373 patients (5.4%) had a positive neural antibody. All anti-LGI1 (N=4), GAD65 (N=4), and GABA(B)R (N=1) were classified as true-positives. In contrast, only 3/6 anti-CASPR2 and 3/5 anti-NMDAR were classified as true-positives. Among true-positives, 2/4 anti-LGI and 3/3 anti-CASPR2 were positive by CBA only. All possible false-positive results exhibited only weak serum staining by CBA, with negative serum TIIF and negative CSF CBA/TIIF (if available). Conclusions: Clinical sensitivity of CBA seems higher than TIIF for neural antibodies studied herein, but may come at some expense to clinical specificity. Among patients with weak serum staining by CBA, correlation with serum TIIF, CSF CBA/TIIF, and clinical presentation is recommended.

False positive results of galactomannan ELISA assay in haemato-oncology patients: A single centre experience

2007 ◽  
Vol 55 (2) ◽  
pp. 201-202 ◽  
Author(s):  
Z.Y. Lim ◽  
A.Y.L. Ho ◽  
S. Devereux ◽  
G.J. Mufti ◽  
A. Pagliuca ◽  
...  
Keyword(s):  
False Positive ◽  
Elisa Assay ◽  
Single Centre ◽  
Oncology Patients ◽  
Single Centre Experience ◽  
Positive Results

scholarly journals Practice Current: When do you suspect autoimmune encephalitis and what is the role of antibody testing?

2018 ◽  
Vol 8 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Aravind Ganesh ◽  
Sarah F. Wesley
Keyword(s):  
Lumbar Puncture ◽  
Sensitivity And Specificity ◽  
Clinical Characteristics ◽  
Online Survey ◽  
Clinical Presentation ◽  
Autoimmune Encephalitis ◽  
Differential Diagnoses ◽  
Antibody Testing ◽  
Case Based

Diagnosing autoimmune encephalitis (AE) is complicated by several factors, including issues with availability, sensitivity, and specificity of antibody testing, particularly with variability in assay techniques and new antibodies being rapidly identified; nonspecific findings on MRI, EEG, and lumbar puncture; and competing differential diagnoses. Through case-based discussions with 3 experts from 3 continents, this article discusses the challenges of AE diagnosis, important clinical characteristics of AE, preferences for methods of autoantibody testing and interpretation, and treatment-related questions. In particular, we explore the following question: If a patient's clinical presentation seems consistent with AE but antibody testing is negative, can one still diagnose the patient with AE? Furthermore, what factors does one consider when making this determination, and should treatment proceed independent of antibody testing in suspected cases? The same case-based questions were posed to the rest of our readership in an online survey, the results of which are also presented.

False positive results in ovarian cancer screening: One year follow-up of psychological status

1994 ◽  
Vol 10 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Jane Wardle ◽  
Amanda Pernet ◽  
William Collins ◽  
Thomas Bourne
Keyword(s):  
Ovarian Cancer ◽  
Cancer Screening ◽  
False Positive ◽  
Psychological Status ◽  
Ovarian Cancer Screening ◽  
One Year ◽  
Positive Results

Reduction in False-Positive PF4/Heparin Antibody Testing Following Implementation of a Latex Immunoturbidimetric Assay

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S34-S34
Author(s):  
Chiraag Gangahar ◽  
Daniel Webber ◽  
Ronald Jackups
Keyword(s):  
Clinical Judgment ◽  
Test Performance ◽  
False Positive ◽  
Clinical Laboratory ◽  
Turnaround Time ◽  
Serotonin Release ◽  
Reference Laboratory ◽  
Antibody Testing ◽  
Release Assay ◽  
Positive Results

Abstract Background Heparin-induced thrombocytopenia (HIT) is a life-threatening complication of exposure to heparin that is caused by autoantibodies against heparin-PF4 complexes. We recently changed our in-house HIT screening platform from a manual, daily batched ELISA (Stago-Asserochrom HPIA Immunoassay) to an automated, on-demand latex immunoturbidimetric assay (LIA, HemosIL HIT-Ab) and have also implemented a reflex from a positive LIA result to the confirmatory serotonin release assay (SRA). We compared the two methods in terms of utilization, test performance, and turnaround time. Methods Data were collected retrospectively from a 7-month period before (June-December 2017) and after (June-December 2018) implementation of the HemosIL LIA in the clinical laboratory at a large academic institution. This study includes consecutive test results from adults (median age: 64 years, range: 19-98 years) seen at our 1,300-bed main hospital. Test utilization, turnaround time (sample receipt to verification), and test performance characteristics were compared between the two methods. Repeat testing was excluded from the analysis. Samples with a positive result on the HemosIL LIA were reflexed to a serotonin release assay (SRA), performed at a large reference laboratory, whereas samples tested with the earlier ELISA assay were referred for SRA testing based upon clinical judgment. When performed, SRA was considered the gold standard for diagnosis of HIT. Results During the 7 months before and after switching methods, there were 109 of 594 (18.4%) positive ELISA results and 45 of 523 (8.6%) positive LIA results. Only 90 of 109 (82%) of the positive results from the ELISA HIT Ab test were sent out by clinicians for SRA testing, whereas 45 of 45 (100%) of the positive results from LIA testing were reflexed to SRA per protocol. Although fewer LIA tests were sent out for SRA testing, there were an equal number of SRA-confirmed cases of HIT with the ELISA (PPV: 16/90 [17.8%]) and LIA methods (PPV: 16/45 [35.6%]), resulting in a high positive predictive value (PPV) with the newly implemented method. Not only was the PPV higher with the LIA test, but it had a significantly shorter mean turnaround time of 96 minutes compared to the ELISA TAT of 1,234 minutes (P < .0001). Conclusions With the new testing protocol, patients received results faster (average 96-minute TAT) and had fewer false-positive results (74/594 pre vs 29/523 post), with no apparent reduction in detection of true-positive cases of HIT (16/594 pre vs 16/523 post).

Mode of initial presentation and chromosomal abnormalities in Irish patients with Turner syndrome: a single-centre experience

2015 ◽  
Vol 28 (11-12) ◽  
Author(s):  
Sarar Mohamed ◽  
Edna F. Roche ◽  
Hilary M.C.V. Hoey
Keyword(s):  
Turner Syndrome ◽  
Clinical Presentation ◽  
Chromosomal Abnormalities ◽  
Ring Chromosome ◽  
Delayed Puberty ◽  
Single Centre ◽  
Important Indicator ◽  
Single Centre Experience ◽  
Wide Range ◽  
Chromosome Material

AbstractAge at diagnosis of girls with Turner syndrome (TS) is an important indicator of successful management. We determined the age, initial clinical presentation, and chromosomal abnormalities in patients with TS.This was a retrospective evaluation of the clinical and laboratory records of patients with TS.Sixty-five patients with TS were identified; 40 (62%) were diagnosed after age 5 years. The main presenting features were short stature, delayed puberty, dysmorphic features, and neonatal lymphoedema. Chromosomal analysis of this cohort showed that 31 patients demonstrated mosaicism, while a 45,X karyotype was observed in 19. The remaining patients had variable abnormalities including deletion, translocation, isochromosome, and ring chromosome. Y-chromosome material was found in four cases.Most patients with TS were diagnosed after age 5 years, had a varied clinical presentation, and had a wide range of chromosomal abnormalities.

scholarly journals Commercial Laboratory IgM Testing forToxoplasma gondiiin Pregnancy: A 20-Year Experience

2005 ◽  
Vol 13 (3) ◽  
pp. 151-153 ◽  
Author(s):  
David J. Garry ◽  
Andrew Elimian ◽  
Vandy Wiencek ◽  
David A. Baker
Keyword(s):  
Predictive Value ◽  
False Positive ◽  
False Positive Rate ◽  
Reference Laboratory ◽  
Antibody Testing ◽  
Commercial Laboratory ◽  
Laboratory Results ◽  
Positive Rate ◽  
Acute Toxoplasmosis ◽  
Positive Results

Objective.This study was performed to review the clinical utility of commercial laboratoryToxoplasmosis-specific IgM testing during pregnancy and outcomes of the gestation at our institution.Methods.A retrospective review of all women referred for suspected acuteToxoplasma gondiiinfection during pregnancy from 1984 through 2004 was performed. Women were diagnosed with suspected acute toxoplasmosis based on commercial laboratory serologic antibody testing. All women had blood sent to a recognized reference laboratory for antibody testing within 2 weeks of the commercial laboratory results. The study protocol was approved by the Institutional Review Board. Chi-square analysis were used with a significance ofP< .05.Results.A total of 130 women were evaluated during the study period with 116 IgM positive results from the commercial laboratories. The commercial laboratory antibodies were as follows: IgM positive with IgG negative (n= 20), IgM positive with IgG positive (n= 96), and IgM negative with IgG positive (n= 14). There was a significant reduction in the IgM positive results when comparing commercial laboratory (n= 116) with the reference laboratory results (n= 28;p< .001). Acute toxoplasmosis infection was diagnosed in 7 (5%) of the women. All cases of acute toxoplasmosis infection had a positive commercial laboratory IgM result. The false positive rate for the commercial laboratory IgM was 88.6% and the diagnostic indices were sensitivity 100%, specificity 11.4%, positive predictive value 6% and negative predictive value 100%.Conclusion.Commercial laboratoryToxoplasmosis-specific IgM is associated with a high false positive rate. The commercial and reference laboratory IgM results identified all cases of acute toxoplasmosis infection. Commercial laboratories reflexively obtaining reference laboratory confirmation of positive results could reduce costs associated with testing, referrals, retesting, and invasive procedures.

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