Helminthic therapy

Helminthic therapy is currently considered a promising alternative treatments for Crohn's disease,  Multiple Sclerosis, asthma, and Ulcerative colitis.

During therapy, patients are inoculated or infected with helminths (parasitic intestinal nematodes such as hookworm, whip worm, etc.) to modulate the patient's immune response and thereby reduce the inflammation and consequent tissue damage associated with each of these diseases.

Indications
There is a great deal of research to suggest that this therapeutic approach is a promising adjunct to existing therapies for Crohn's, Asthma, Eczema, Dermatitis, Hay fever, Colitis and Multiple Sclerosis. For instance remission for Crohn's patients was 72.4% for otherwise non-refractive patients in one study using TSO, 100% in another study using hookworm, and 66% for asthma sufferers in another using hookworm.

There are reasons to believe that it may have value in the treatment of many other autoimmune diseases and immunological disorders that have similar underlying immunological mechanisms to Crohn's, etc. For instance Rheumatoid Arthritis, Type I Diabetes, Parkinson's disease, Sinusitis all have characteristics that suggest Helminthic Therapy may be beneficial. Although for diseases involving tissue damage the main benefit would be prophylactic, since nothing can undo tissue necrosis and scarring.

Side effects
The potential benefits of Helminthic Therapy are even more startling when taken in the context of the success rates and side-effects experienced by people on currently accepted medications that are immune-modulating and or anti-inflammatory. Side effects of Helminthic Therapies are not universal and are temporary, usually lasting only two to four weeks. They consist of abdominal pain, cramping, gas, diarrhea and fatigue. The side effects of conventional immune-modulating drugs, such as Beta-interferon and Remicade, or of anti-inflammatories such prednisone, are much more severe and potentially harmful.

Origins
The origins of Helminthic Therapy lie in the Hygiene hypothesis which was developed to explain the observation that hay fever and eczema, both allergic diseases, were less common in children from larger families, which were presumably exposed to more infectious agents through their siblings, than in children from families with only one child. Epidemiological studies have since established that an even greater difference in the distribution of autoimmune disease exists between industrialized countries and those of less developed nations. Autoimmune diseases, like Multiple Sclerosis, Asthma and Inflammatory bowel diseases are increasingly common in Western industrialized countries, but are much more rare in developing countries where people live in less sanitized environments. The still developing hygiene hypothesis suggest that childhood exposure to bacteria and viruses that have been largely eliminated in industrialized countries may be one cause. Another possible explanation that has been suggested for the increase in atopy and autoimmune disease in the industrialized West is the elimination of parasitic intestinal worms. There is a great deal of research that strongly suggests that the elimination of helminths causes the human immune system to over-react, resulting in inflammation in various areas of the body depending on the genetic make up of the individual. The result is Multiple Sclerosis, Crohn's/Colitis or Asthma depending on where the inflammation occurs.

Providers
Ovamed is the pioneer in this area of medicine. It was founded to commercialize the work of Joel Weinstock at the University of Iowa (see trial results below). The ova of the porcine (pig) whipworm Trichuris suis are shipped to patients in suspension. This suspension is called TSO for Trichuris Suis Ova. Patients ingest the TSO for a period of time, usually at least eight weeks.

Autoimmune Therapies is the first company to offer human hookworm to treat autoimmune disease. They offer inoculation with necator americanus (hookworm) by a physician at a clinic in Mexico.

Hookworm and TSO
Helminthic therapy with both hookworm and TSO has been investigated in research published by the University of Nottingham and University of Iowa. Both TSO and Hookworm are well tolerated, and safe at therapeutic doses. Neither organism is by any standard definition infectious in the industrialized world. That is neither presents an infection risk to others from a treated individual. Nor does either organism proliferate within the host once established.

Hookworm depend upon a period of eight to ten days outside the host within narrow environmental parameters to become infectious after being passed in stool. Trichuris suis is similar to the human whipworm Trichuris trichiura, but its normal host is pigs. T. suis can colonize people but only for a short term and the worms cannot replicate in people.

For this reason treatment with TSO requires regular doses, at intervals of two weeks. Treatment with hookworm requires inoculation at intervals of approximately five years. This is because the average life expectancy of necator americanus is 3-10 years.

Crohn's Disease and Ulcerative Colitis Trichuris Suis Ova Trial results
A 24 week trial with 29 Crohn's disease patients showed remarkable results. After 24 weeks 79.3% of the patients showed a response to the treatment and 72.4% of the patients were in remission. 100% of patients which were on immunosupressive treatment at the time of the study showed a response to the treatment after 24 weeks.

A double-blind, placebo-controlled trial with 59 Ulcerative Colitis patients was done by the same group of researchers. Combining data of the trial, 47.8% of the patients given helminths showed a response compared to 15.4% of those who received a placebo. No side effects or complications were reported.

Asthma Necator Americanus Meta Analysis results
Epidemiologic studies indicate that hookworm infections may protect against asthma. A systematic review and meta-analysis of epidemiologic studies was undertaken to determine whether total or species-specific current parasite infection is associated with a reduced risk of asthma or wheeze. MEDLINE, EMBASE, and CINAHL (up to January 2006) were searched. Studies that reported asthma or wheeze as an outcome measure and ascertained parasite infection by fecal examination were included. Thirty-three studies met the inclusion criteria.

In general, parasite infection was associated with a small non-significant increase in asthma risk. But in species-specific analysis, the highest tertile level of hookworm infection was associated with a significantly strong reduction (66%) in asthma risk.