IgG-specific cell-based assay detects potentially pathogenic MuSK-Abs in seronegative MG

Saif Huda; Patrick Waters; Mark Woodhall; Maria Isabel Leite; Leslie Jacobson; Anna De Rosa; Michelangelo Maestri; Roberta Ricciardi; Jeannine M. Heckmann; Angelina Maniaol; Amelia Evoli; Judy Cossins; David Hilton-Jones; Angela Vincent

doi:10.1212/NXI.0000000000000357

Full PDF

Citation

Permissions

Make Comment

See Comments

Downloads

1321

Article Figures & Data

Figures

Tables
Additional Files

Download figure

Open in new tab

Download powerpoint

Figure 1 CBA with anti-IgG(H+L)
(A) Scatter plots of results from patients and controls. (B) Representative CBA images from SNMG and HC sera. Scale bar = 50 μM. (C) Colocalization of commercial MuSK-AF562 antibody (red) with anti-IgG(H+L) (green) in an SNMG serum. Scale bar = 20 μM. CBA = cell-based assay; HC = healthy control; MG = myasthenia gravis; SNMG = seronegative MG.
Download figure

Open in new tab

Download powerpoint

Figure 2 Improving the CBA with anti-IgG Fc(γ)
(A) Antibodies in 2 Definite MuSK-MG sera were mainly IgG subclasses, particularly IgG1 and IgG4. By contrast, 12 SNMG sera detected with anti-IgG(H+L) were also detected with anti-IgM secondary antibody but not with anti-IgG subclass secondary antibodies. (B) Representative CBA images of a Definite MuSK-MG serum detected with anti-IgG Fc(γ). Scale bar = 50 μM. (C) End-point titrations in 4 Definite MuSK-MG sera were higher with IgG Fc(γ) vs IgG(H+L). (D) Scatter plots of results from the SNMG patients and 51 disease and healthy controls. CBA = cell-based assay; MG = myasthenia gravis; SNMG = seronegative MG.
Download figure

Open in new tab

Download powerpoint

Figure 3 Functional effects of MuSK-IgG and IgM on agrin-LRP4-MuSK–clustering pathway
(A) Representative images of myotubes, fluorescent labeled for AChR clusters in the presence of different sera. Definite MuSK-MG and CBA MuSK-IgG–positive sera reduced the number of AChR clusters, but CBA MuSK-IgM sera did not reduce clusters. Scale bar = 50 μM. (B) Mean results from 2 experiments of CBA MuSK-IgG and control sera on AChR clusters. (C) Mean results of 2 experiments with CBA MuSK-IgM–positive and control sera. Values shown are mean + SEM. HC = healthy control; MG = myasthenia gravis.

Additional Files

Figures
Tables

Data Supplement

Files in this Data Supplement:

Figure e-1 - Microsoft Word file

Letters: Rapid online correspondence

No comments have been published for this article.

Comment

REQUIREMENTS

If you are uploading a letter concerning an article:
You must have updated your disclosures within six months: http://submit.neurology.org

Your co-authors must send a completed Publishing Agreement Form to Neurology Staff (not necessary for the lead/corresponding author as the form below will suffice) before you upload your comment.

If you are responding to a comment that was written about an article you originally authored:
You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid
and apply to letter.

Submission specifications:

Submissions must be < 200 words with < 5 references. Reference 1 must be the article on which you are commenting.
Submissions should not have more than 5 authors. (Exception: original author replies can include all original authors of the article)
Submit only on articles published within 6 months of issue date.
Do not be redundant. Read any comments already posted on the article prior to submission.
Submitted comments are subject to editing and editor review prior to posting.

More guidelines and information on Disputes & Debates

Compose Comment

Title *

Author Information

NOTE: The first author must also be the corresponding author of the comment.

Authors
First Name and Middle Initial * First or given name, e.g. 'Peter'. Last Name * Your last, or family, name, e.g. 'MacMoody'. Email Address * Your email address, e.g. higgs-boson@gmail.com Occupation * Your role and/or occupation, e.g. 'Orthopedic Surgeon'. Affiliation * Your organization or institution (if applicable), e.g. 'Royal Free Hospital'.

Publishing Agreement

I, the first and corresponding author, verify that I have read the contents of the PUBLISHING AGREEMENT form. *

I, the first and corresponding author, verify my disclosures and those of my co-authors are up to date at http://submit.nn.neurology.org. *

Select only one of the three options below: *

I am an Author of this Work, and the Work was prepared on my own time - not as part of my duties as an employee.

I prepared (or cooperated in the preparation of) the Work as part of my duties as an employee, and the Work is, therefore, a "work made for hire", as defined by the United States Copyright Act of 1976, as amended.

I prepared (or participated in the preparation of) the Work as part of my official duties as an officer or employee of the United States Government.

NOTE: All authors, besides the first/corresponding author, must complete a separate Publishing Agreement Form and provide via email to the editorial office before comments can be posted.

CAPTCHA

This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

Vertical Tabs

Topics Discussed

Alert Me

Alert me when eletters are published

Main menu

User menu

Search

IgG-specific cell-based assay detects potentially pathogenic MuSK-Abs in seronegative MG

Citation Manager Formats