scholarly journals Aquaporin-4 Autoantibody Detection by ELISA: A Retrospective Characterization of a Commonly Used Assay

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Jon P. Williams ◽  
Justin R. Abbatemarco ◽  
Jonathan J. Galli ◽  
Stefanie J. Rodenbeck ◽  
Lisa K. Peterson ◽  
...  

Objective. Aquaporin-4 (AQP4) serum autoantibodies are detected by a variety of methods. The highest sensitivity is achieved with cell-based assays, but the enzyme-linked immunosorbent assay (ELISA) is still commonly utilized by clinicians worldwide. Methods. We performed a retrospective review to identify all patients at the University of Utah who had AQP4 ELISA testing at ARUP Laboratories from 2010 to 2017. We then reviewed their diagnostic evaluation and final diagnosis based on the ELISA titer result. Results. A total of 750 tests for the AQP4 ELISA were analyzed, and 47 unique patients with positive titers were identified. Less than half of these patients (49%) met the clinical criteria for neuromyelitis optica spectrum disorder (NMOSD). In cases of low positive titers (3.0–7.9 U/mL, n = 19 ), the most common final diagnosis was multiple sclerosis (52.6%). In the moderate positive cohort (8.0–79.9 U/mL, n = 14 ), only a little more than half the cohort (64.3%) had NMOSD. In cases with high positives (80–160 U/mL, n = 14 ), 100% of patients met clinical criteria for NMOSD. Conclusions. Our data illustrates diagnostic uncertainty associated with the AQP4 ELISA, an assay that is still commonly ordered by clinicians despite the availability of more sensitive and specific tests to detect AQP4 autoantibodies in patients suspected of having NMOSD. In particular, low positive titer AQP4 ELISA results are particularly nonspecific for the diagnosis of NMOSD. The importance of accessibility to both sensitive and specific AQP4 testing cannot be overemphasized in clinical practice.

Mechatronics ◽  
2003 ◽  
Vol 13 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Sanford Meek ◽  
Scott Field ◽  
Santosh Devasia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Markus H. Kainulainen ◽  
Eric Bergeron ◽  
Payel Chatterjee ◽  
Asheley P. Chapman ◽  
Joo Lee ◽  
...  

AbstractSARS-CoV-2 emerged in late 2019 and has since spread around the world, causing a pandemic of the respiratory disease COVID-19. Detecting antibodies against the virus is an essential tool for tracking infections and developing vaccines. Such tests, primarily utilizing the enzyme-linked immunosorbent assay (ELISA) principle, can be either qualitative (reporting positive/negative results) or quantitative (reporting a value representing the quantity of specific antibodies). Quantitation is vital for determining stability or decline of antibody titers in convalescence, efficacy of different vaccination regimens, and detection of asymptomatic infections. Quantitation typically requires two-step ELISA testing, in which samples are first screened in a qualitative assay and positive samples are subsequently analyzed as a dilution series. To overcome the throughput limitations of this approach, we developed a simpler and faster system that is highly automatable and achieves quantitation in a single-dilution screening format with sensitivity and specificity comparable to those of ELISA.


1995 ◽  
Vol 117 (3) ◽  
pp. 200-204 ◽  
Author(s):  
K. Pierce ◽  
A. C. Hansen

The Beddoes-Leishman model for unsteady aerodynamics and dynamic stall has recently been implemented in YawDyn, a rotor analysis code developed at the University of Utah for the study of yaw loads and motions of horizontal axis wind turbines. This paper presents results obtained from validation efforts for the Beddoes model. Comparisons of predicted aerodynamic force coefficients with wind tunnel data and data from the combined experiment rotor are presented. Also, yaw motion comparisons with the combined experiment rotor are presented. In general the comparisons with the measured data are good, indicating that the model is appropriate for the conditions encountered by wind turbines.


1986 ◽  
Vol 70 (493) ◽  
pp. 73-74
Author(s):  
Ann Weaver Hart

2011 ◽  
Vol 18 (5) ◽  
pp. 578-586 ◽  
Author(s):  
Woojun Kim ◽  
Ji-Eun Lee ◽  
Xue Feng Li ◽  
Su-Hyun Kim ◽  
Byeong-Gu Han ◽  
...  

Background: Antibodies to aquaporin-4 (AQP4-Ab), known as NMO-IgG, are a sensitive and specific marker for neuromyelitis optica (NMO). Methods: To develop an enzyme-linked immunosorbent assay (ELISA) for AQP4-Ab, we expressed M23 isoform of human AQP4 in a baculovirus system, and used it as an antigen. We measured AQP4-Ab in the sera of 300 individuals: 64 with definite NMO, 31 with high-risk NMO, 105 with multiple sclerosis (MS), 57 with other neurological diseases (ONDs), and 43 healthy controls. We also performed longitudinal measurements of AQP4–Ab in 787 samples collected from 51 patients with definite or high-risk NMO. Results: AQP4-Abs were positive in 72% with definite NMO, 55% with high-risk NMO, and 4% with MS, but none of the OND patients and the healthy individuals. The longitudinal measurement showed AQP4-Ab levels correlating with disease activity. Out of 38 initially seropositive patients, 21 became seronegative under effective immunosuppressive therapy. During most relapses, the serum AQP4-Ab levels were either high or rising compared with the previous value, although rising AQP4-Ab levels did not always lead to acute exacerbation. Two of the 13 initially seronegative patients converted to seropositive following acute exacerbations. Conclusions: We established an AQP4-Ab ELISA, which could be a potential monitoring tool of disease activity.


JOM ◽  
1985 ◽  
Vol 37 (11) ◽  
pp. 33-34
Author(s):  
H. Y. Sohn ◽  
J. A. Herbst

2004 ◽  
Vol 32 (2) ◽  
pp. 336-337 ◽  
Author(s):  
G.D. Prestwich

Cells signal through lipids produced by phospholipid and phosphoinositide metabolism that involves three enzymic processes: (i) ester and phosphodiester hydrolysis by phospholipases; (ii) monophosphate hydrolysis by phosphatases; and (iii) phosphorylation of hydroxy groups by kinases. Unregulated enzyme activity correlates with specific pathologies, which are specific targets for therapeutic intervention. Three categories of reagents developed at the University of Utah and at Echelon Biosciences permit monitoring of in vitro enzyme activity and spatiotemporal changes in intracellular lipid concentrations, and identification of lipid–protein interactions.


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