Immunosignature Analysis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) (2018) Fluge et al.

[Cheshire]

A random-sequence peptide microarray can interrogate serum antibodies in a broad, unbiased fashion to generate disease-specific immunosignatures. This approach has been applied to cancer detection, diagnosis of infections, and interrogation of vaccine response. We hypothesized that there is an immunosignature specific to ME/CFS and that this could aid in the diagnosis.

We studied two subject groups meeting the Canadian Consensus Definition of ME/CFS. ME/CFS (n = 25) and matched control (n = 25) sera were obtained from a Canadian study. ME/CFS (n = 25) sera were obtained from phase 1/2 Norwegian trials (NCT01156909). Sera from six healthy controls from the USA were included in the analysis. Canadian cases and controls were tested for a disease immunosignature. By combining results from unsupervised and supervised analyses, a candidate immunosignature with 654 peptides was able to differentiate ME/CFS from controls. The immunosignature was tested and further refined using the Norwegian and USA samples.

This resulted in a 256-peptide immunosignature with the ability to separate ME/CFS cases from controls in the international data sets. We were able to identify a 256-peptide signature that separates ME/CFS samples from healthy controls, suggesting that the hit-and-run hypothesis of immune dysfunction merits further investigation.
By extending testing of both our signature and one previously reported in the literature to larger cohorts, and further interrogating the specific peptides we and others have identified, we may deepen our understanding of the origins of ME/CFS and work towards a clinically meaningful diagnostic biomarker.

https://link.springer.com/article/10.1007/s12035-018-1354-8

Edit: Text breaks are mine.

 

[Alvin]

Does this mean that 256 tests need to be done to differentiate ME from controls or one molecule that has 256 parts in it?

 

[Jonathan Edwards]

Does this mean that 256 tests need to be done to differentiate ME from controls or one molecule that has 256 parts in it?

I assume that they have 256 different peptide molecules, a tiny dab of each of which is put on to a different pin or well in an array.The patient's serum is then added and the pattern of antibody binding to the 256 pins (wells) is visualised using a fluorescent or otherwise tagged developer reagent. So each patient and control provides a pattern of 256 spots of different brightness. You put these into computer and it tells you whether it is a patient pattern or a control pattern - like a barcode really.

What the text quoted above does not say is how well the pattern replicated across populations. With enough dots in the array you can always find a signature for patients, but it may be just a chance pattern in that sample.

 

[Alvin]

I assume that they have 256 different peptide molecules, a tiny dab of each of which is put on to a different pin or well in an array.The patient's serum is then added and the pattern of antibody binding to the 256 pins (wells) is visualised using a fluorescent or otherwise tagged developer reagent. So each patient and control provides a pattern of 256 spots of different brightness. You put these into computer and it tells you whether it is a patient pattern or a control pattern - like a barcode really.

What the text quoted above does not say is how well the pattern replicated across populations. With enough dots in the array you can always find a signature for patients, but it may be just a chance pattern in that sample.

Interesting, thanks for explaining

 

[Hutan]

One group of samples were from the earlier rituximab trials.

In this study, subjects improving according to the predefined criteria in the protocol were characterized as responders. For the analyses in this manuscript, we used only the pretreatment samples from subjects in the trial.

So presumably one thing to watch out for will be another paper that applies the same protocol to generate immunosignatures from the post-treatment samples, to see if there are any interesting differences between the responders and non-responders and if the responders' immunosignatures look more like those of the healthy controls. Sample sizes are small of course.