I got a wonderful email this past Friday, and have been very much looking forward to sharing it with you all this week.
A friend from the helminthic therapy world sent me a “Happy Anniversary” message, celebrating the 50th year since the publication of the first paper[i] noting that exposure to helminths is associated with a decrease in autoimmune disease. John went on to point out, by the way, that during these 50 years, 660 papers have been published on the topic of helminthic therapy…and the traditional medicine world still manages to ignore them all. (You can see these papers here. John, and a group of other devoted helminth users, put these Wiki pages together – which had to have been a monumental task and is an amazing achievement.)
The paper is remarkable in its almost psychic vision of the future. But I’ll come back to that. First, to describe the paper’s findings:
Dr. Greenwood, a doctor at a major Nigerian hospital, noted the remarkably low incidence of autoimmune diseases in Africa. He catalogues a plethora of diagnoses, ranging from rheumatoid arthritis to Addison’s disease, pointing out how few cases of each have ever been reported. For example, at the time of writing, “Primary Addison’s disease does not seem to have been reported in Africa.”
He then tallied the patient diagnoses in the University College Hospital, in Ibadan, Nigeria (where he worked), over the period 1957-1966 and found, “…there were only 104 patients with autoimmune diseases out of a total of 98,454 admissions.” To find out how this compared to disease rates in an industrialized country of temperate climate, he chose to use the example of the diagnosis of rheumatoid arthritis: “…rheumatoid arthritis was found to account for only a sixth as many admissions to hospital in Western Nigeria as to hospitals in England and Wales.”
In his discussion, Dr. Greenwood answers the question of whether these difference are genetic or environmental: “The common occurrence of systemic lupus erythematosus, thyrotoxicosis, and pernicious anemia in American Negroes, and of rheumatoid arthritis in Jamaican Negroes, suggests that environmental factors are of considerable importance.” He notes, in fact, that the immune differences they found in African natives is NOT found in those of African birth who have moved to England or America.
What could be the cause of this? Since it’s obviously environmental, Dr. Greenwood looked at differences in exposures between those people living in tropical Africa and those living in industrialized countries and came to a prophetic hypothesis:
- “As a result of the present survey it is postulated that the rarity of autoimmune disease in Western Nigeria, and possibly in other parts of tropical Africa, is similarly related to an altered immunological state produced by multiple parasitic infections since childhood.”
- And most remarkably, about a decade before the first cytokine had even been discovered (late 1970s)[ii], and 21 years before interleukin-10 (one of the primary regulatory cytokines) was identified[iii], Dr. Greenwood proposed a remarkably prescient theory: “Reduction of the sensitivity of the immune mechanism to the factors responsible for the production of autoimmune disease by the massive antigenic stimulus of multiple heavy parasitic infections is an alternative hypothesis that could explain the postulated inverse relationship between parasitic infections and autoimmune disease.” That is, the immune changes wrought by exposure to helminths leads to greater immune tolerance and a modulated inflammatory response, and thus, a dramatic decrease in autoimmune disease.
So happy golden anniversary of the concept of helminthic therapy, everyone!
[i] Greenwood, BM.. Autoimmune disease and parasitic infections in Nigerians. The Lancet. 1968:17;2(7564):380-2.
[ii] Dinarello, CA. Historical review of cytokines. European Journal of Immunology. 2007:37(suppl 1):S34-S37.