In a small study from Argentinia. There were only 24 patients, but the results were so strong the Dr involved felt it was worth publishing. The control group suffered fifty six relapses, the parasite infested group only three, about 1/18th the number of attacks. I found this article from Medscape:
Parasitic Infection May Benefit MS Patients
January 24, 2007 — Parasitic infection in multiple sclerosis (MS) may benefit patients by modulating the immune response and altering the natural course of the disease, a new study suggests.
Investigators from the Raúl Carrea Institute for Neurological Research in Buenos Aires, Argentina, found that MS patients with eosinophilia caused by intestinal parasites had a significantly lower number of relapses, minimal changes in disability scores, and significantly lower activity on magnetic resonance imaging (MRI) compared with uninfected MS patients.
“Parasitic infection has been shown to alter the immune response and confer a protective effect in animal models. However, this is the first time it has been shown in humans with MS,” the study’s principal investigator, Jorge Correale, MD, told Medscape.
The study was published online January 17 in the Annals of Neurology.
The prospective, double-cohort study, which recruited from a large cohort of 432 regularly followed MS patients, included 12 patients with a diagnosis of clinically definite relapsing-remitting MS and eosiniophilia.
Patients had a mean age of 34 years, a mean extended disability status scale (EDSS) score of 2.8, and mean disease duration of 7.3 years. The study also included 12 patients without eosinophilia and 12 healthy individuals, who served as control subjects.
Patients were subjected to a comprehensive neurological examination every 3 months, including physical assessment of disease activity and EDSS scoring.
Brain MRIs were performed every 6 months, while immunological evaluations were conducted during the last 12 to 18 months of the study, which had an average follow-up of 4.6 years.
Over the study period, 3 clinical relapses occurred in the infected MS group, with 9 patients remaining clinically unchanged. In contrast, there were 56 relapses observed in the uninfected group. The median annual relapse rate was 0 in the infected MS group vs 1.09 in the uninfected group.
Furthermore, only 2 infected patients had changes in their EDSS scores, which were characterized as “minimal” and lasted less than 3 months. There was no change in EDSS scores in the remaining 10 infected subjects. In comparison, by the end of the study, 11 of 12 uninfected patients showed an overall increase in baseline EDSS.
In addition, the presence of new or enlarging T2 MRI lesions was evaluated. Among infected MS patients, 14 new or enlarging T2 MRI lesions were detected. In 6 patients, however, scans remained unchanged throughout the study period.
In stark contrast, there were 164 new or enlarging T2 MRI lesions registered in uninfected MS subjects. Furthermore, only 3 relapses were observed among the infected group vs 48 in the uninfected subjects.
Lack of Disease Progression
The lack of disease progression in patients with a parasitic intestinal infection is likely due to the ability of parasites to dampen inflammatory reactions that are characteristic of autoimmune diseases, said Dr. Correale.
Specifically, he said, MS is a Th1-mediated disease. Th1 produces proinflammatory cytokines — specifically, gamma interferon, the main cytokine responsible for MS. When patients acquire a parasitic infection, they develop 3 different cell populations — Tr1, which produces interleukin 10; Th3, which produces TGF-ß; and CD4+CD25+T cells, which modulate Th1 cells and specifically interfere with the production and proliferation of gamma interferon.
In their paper, the authors point out that parasites can inhabit immune-competent hosts for long periods of time. Indeed, said Dr. Correale, these patients were infected for almost 5 years and had few, if any, symptoms. It may be that to ensure its survival, the parasite produces molecules that generate a strong anti-inflammatory response.
Dr. Correale pointed out that the prevalence of MS in Latin American countries is much lower than in Europe or the United States. The higher prevalence of parasitic infections in Latin American countries may be one possible environmental factor that protects MS patients, lowering the prevalence of the disease, he said.
Dr. Correale said his next research steps will be to attempt to replicate these findings in a larger group of patients in a blinded fashion and with longer follow-up.
However, longer-term research goals, he said, will focus on isolating particular molecules produced by the parasite responsible for modulating the immune response and ultimately testing its therapeutic effect.
Upon comparing the results of this study (about a 1,800% improvement) with the results for the new MS treatment undergoing trials (about 70% improvement) I am a little bemused as to why all the time and energy is going into the drug trials, which have a far less impressive outcome (about 20 times less impressive), and more potentially harmful side effects than a controlled parasitic infection. No cash in it for the drug companies I suppose.