I posted some information under the thread "Some Interesting Connections" on the MS disease process, which I believe the evidence shows originates with a lack of enzymes called protease and DNase 1.
One of the things that results from a lack of these enzymes is the activation of a tryptophan degrading pathway called the "kynurenine pathway."
Here is some of the information I posted on the thread about the kynurenine pathway and MS.
"The following study confirms that kynurenine pathway activity is involved in MS. The researchers found elevated levels of the toxic tryptophan metabolite “kynurenic acid” in patients with MS and concluded their data demonstrated the involvement of the kynurenine system in the pathogenesis of MS.
Acta Neurol Scand. 2005 Aug;112(2):93-6.
Kynurenine metabolism in multiple sclerosis.
Hartai Z, Klivenyi P, Janaky T, Penke B, Dux L, Vecsei L.
“…The concentration of kynurenic acid is elevated in the plasma of MS patients, and there is a tendency to an elevation in the RBC…Our data demonstrate the involvement of the kynurenine system in the pathogenesis of MS…”
Researchers in the following study stated that evidence has progressively emerged suggesting that the kynurenine pathway (KP) is involved in the pathogenesis of autoimmune diseases, especially MS.
Int J Tryptophan Res. 2010; 3: 157–167.
Understanding the roles of the kynurenine pathway in multiple sclerosis progression.
Chai K. Lim,1 Bruce J. Brew,2,3 Gayathri Sundaram,1 and Gilles J. Guillemin1
“…The KP is known to be involved in several neuroinflammatory disorders including Alzheimer's disease, amyotrophic lateral sclerosis, AIDS dementia complex, Parkinson's disease, schizophrenia, Huntington's disease and brain tumours…Over the last 2–3 years, some evidence has progressively emerged suggesting that the KP is likely to be involved in the pathogenesis of autoimmune diseases especially MS. Some KP modulators are already in clinical trials for other inflammatory diseases and would potentially provide a new and important therapeutic strategy for MS patients…”
The chronic activation of the KP affects the proper functioning of T-cells and results in immune deficiencies. Here is a link to a great slide show presentation on what the KP is and how it can result in immune deficiency.
http://www.slideboom.com/presentations/184613
As far as your reaction to your medications, MS patients also have a dysfunction in the cytochrome P450 enzyme system. The cytochrome P450 system detoxifies all sorts of different chemicals that we eat and breathe, including drugs, carcinogens formed in cooking, and poisonous compounds in plants (Guengerich, 2008). I discuss the reason for this dysfunction on the thread.