Notes on CIDP–part 3
see disclaimer at the top of the thread.
[B]Time for therapies to work[/B]
There was discussion about how long it took therapies to work. IV IgG and PE were fastest. Steroids pretty fast but not as fast as those. Cyclosporin and cyclophosfamide may work next fastest. Methotrexate, azathioprine, and mycophenolate seem to take a long time to work—possibly as long as 12-18 months. When deciding if a treatment is working, IV IgG or steroids should get at least a three month trial, but azathioprine may need a trial to determine effectiveness of as long as 18 months.
[B]Determining if something works.[/B]
There was discussion about these points.
Definition and subgroups of CIDP
Doses and duration of the trials as too small a dose or too short a trial can adversely effect results and make one think that a medication may not work when it potentially would at a higher dose or if given more time to work.
Scales for assessing benefit. The current scales are not optimal.
There was discussion that in myasthenia gravis, progress has been made once they started defining not only remission off medications but also pharmacological remission (remission due to the use of drugs).
[B]Long term outcomes.[/B]
In a paper from 2006 JNNP with author Kuwasera or something like that, 38 patients with CIDP who had been treated with any therapy was looked at back in time to see how many improved. About ¼ were said to have a complete response, 60% a partial response, and the remaining 10-15% got worse despite any treatment given. The percentage of people responding to any of the big 3 is about 60-80% and none have been statistically proven to be better than the other in the CIDP population.
[B]Features that affect Chances of not doing as well[/B]
Delay to start treatment for more than a year
There was discussion of the huge impact that this illness has socioeconimically. About 40% of the patients in the outcomes survey had been on prolonged disability and about a 30% still were. More than half had to stop working for on average 5 years. There were on average long hospitalizations. IV IgG is very expensive. The illness and treatments for it have a high medical cost, but there is also a huge societal cost in lost work. Because the latter is so much greater than the former and because the impact on individual patients is so great, more studies of treatment need to be done even though this is a rare disease. .
Many thanks to the many neurologists that so kindly provided information and answered questions at these talks including Drs Lewis, Hughes, Barohn, Koshi, Lisak, and Parry and the others no less important. This is an awesome group of neurologists and they deserve to be honored for their committment to these rare disorders.