Immunological Disorders and Immunotherapy
Open Access

Short Note on Helminthic Immunotherapy

Martin J Menon^{* *}Correspondence: Martin J Menon, Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine, NY 10010, USA, Email:

Author info »

Description

The patient is inoculated with specific parasite intestinal nematodes in helminthic therapy (or other helminths). Trichuris suis ova, commonly known as pig whipworm eggs; Necator americanus, commonly known as hookworms; Trichuris trichiura ova, commonly known as human whipworm eggs; and Hymenolepis diminuta, commonly known as rat tapeworm cysticerci, are among the organisms currently being studied for their potential use as treatment.

According to certain studies, helminths have evolved alongside their hosts over millions of years. As a result, they've learnt the art of suppressing and changing their hosts' immune responses. The body's early immunological response is weakened by a parasite infection. In other situations, however, these immune system alterations can benefit the host by lowering overall inflammation. One of the reasons why some scientists are interested in helminth therapy is because of this benefit.

Risks factors

The worms may create significant negative effects over time. An increased risk of anaemia is one of them. In some patients, a protein deficit can also develop, impairing their ability to think and stunting their physical growth.

There are medications available to help with these negative effects. Iron supplements may be administered for anemia in those receiving helminthic therapy.

Effectiveness

Scientists are still unsure if helminth therapy is helpful. Although helminth infections appear to have beneficial effects on inflammatory disorders, research suggests that these effects are limited to persons who have had a helminth infection prior to developing an inflammatory condition.

Researchers looked at various animal studies that looked at the impact of helminths on inflammatory bowel illness, such as Crohn's disease and ulcerative colitis, in a 2018 review. Despite the fact that many of these findings were encouraging, the authors have no way of knowing if similar effects will occur in humans.

Human research is still inconclusive. Over the course of 12 weeks, a 2017 study investigated the effects of a species of helminth on adults with Crohn's disease. The participants in the study were divided into four groups by the researchers. Three of these groups were given various doses of helminth eggs, whereas the fourth group was given a placebo.

Participants in the group that received the largest dose of helminth eggs were somewhat more likely to go into remission than those in the placebo group, but those in the other two groups were less likely. Furthermore, laboratory tests revealed that all of these groups had the same amounts of inflammation.

Is it approved for use?

Helminth therapy is an investigational treatment that has not been licenced by the Food and Drug Administration (FDA). As a result, doctors in the United States are unable to recommend helminth therapy as a treatment.

Long-term studies on helminth therapy are insufficient to determine if it is safe. Furthermore, medical research has yet to figure out how to administer helminth therapy in a regulated and ethical manner.

Certain worm species, such as pig whipworm and human hookworm, have been awarded Investigational New Drug designation by the FDA. The worms can now be tested in people by researchers in the United States.

Mechanism of action proposed

Concept that clinically induced helminthic infections can alleviate or mitigate immunological responses is supported by experimental findings. Most autoimmune illnesses are thought to be caused by overactive TH1 or TH17 immune responses that are suppressed by helminths' stimulation of a TH2 response. Helminths release immune-regulatory chemicals that enhance regulatory T cell induction while suppressing antigen presentation cells and other T cells. As a result, helminthic therapy tries to re-establish homeostasis by switching from a high TH1 pro-inflammatory response to a TH2 response with less inflammation.

In human and animal studies, reduced TH1 and TH17 immune responses were associated with a shift to TH2 cytokine production, resulting in significantly lower levels of interleukin 12 and IFNy and concurrent increases in regulatory T cells, interleukin 4, interleukin 5, and interleukin 10 in test subjects. These findings suggest that helminth therapy can protect against autoimmune illness not only through prevention, but also after autoimmune reactions have begun, because helminths can be present before autoimmune disease occurs. Furthermore, type-2 T helper cell responses seldom kill parasitic worms.