Jonathan Edwards
Senior Member (Voting Rights)
But how could severe ME have a different starter pathway if some people start off mild and stay that way for many years before becoming severe, and some lucky people who have been severe for many years recover to a moderate or mild level over time?
When I say starter pathway I do not necessarily mean that would be early in the disease course in time terms. This is very complicated to explain but I think the answer to all your questions might be that the casual pathways of ME/CFS may, like rheumatoid arthritis, involve something like fifty steps, each of which may be mediated by alternative versions.
The extreme example of this perhaps is that the step in RA where small immune complexes form and can bind to receptors to activate inflammation can be mediated by potentially a million different antibody species. Some of these might all be pretty similar in how they bind to each other but others might be significantly different in hundreds of ways.
The trick is to find an overall model for the pathway network that you can make predictions from without knowing absolutely every detail - which is what we did for using rituximab.
There are big question marks about how cohorts get selected for studies and there is not doubt that the lack of a signal in severe cases is puzzling, but it isn't so odd to me that I would be sceptical about the validity of the findings on those grounds.