Our immune system is quite complicated, with many factors at play. One aspect of any immune disease (autoimmune, allergies, asthma etc) is the relationship between Th1 and Th2. To simplify any immune condition to my patients, I use a simple balance-scale analogy to describe the impact of Th1 and Th2, which will be discussed shortly.
An Introduction to Our Immune System
Our immune system what helps fight off infection. We rely on it to turn on when we have an infection, and then turn off when the infection is gone. The immune system turning on is just as important as it is knowing when to turn off again. There are various cell types involved in this process, but one group is CD4+ T helper cells. Within this family of CD4+ T helper cells, there are four types– TH1 (aka Type 1) and TH2 (aka Type 2) cells (the focus of this article), plus Th17 and Tregulatory cells (which will be discussed in other articles). The effects of TH1 and TH2 CD4+ helper T cells vary drastically and have established relationships to allergies and autoimmune disease.
The way these Th1 and Th2 cells work is by releasing chemical mediators called cytokines. TH1 T helper cells produce INF-gamma, IL-2, TNF-b, which evoke cell mediated immunity and phagocyte-dependant inflammation. TH2 helper T-cells produces IL-4, IL-5, IL-6, IL-9, IL-10, IL-13 – evoking strong antibody responses .
A Balanced Immune System is a Healthy Immune System
I use the analogy of a weigh-balance scale to describe the balance of our immune system. In optimal health: Th1 and Th2 are in balance.
Th1 deals with viral and bacterial infections. It’s the body’s first response to pathogens. It relies on other cells to kill the invading pathogen – hence we call it cell-mediated. We call this the innate immune system and it’s associated with inflammatory reactions.
Th2 deals with infections too – particularly parasitic infections. They rely on antibodies to do their work – hence we call this anti-body mediated. Th2 tends not to be inflammatory.
When we get sick, one arm of this system will activate– in order to fight the infection off. It’s important to note that once the infection is clear, balance is regained.
Th1 and Th2 in Dysfunction
In some cases, people are in a state of Th1 or Th2 Dominance. Rather than having a balanced scale, they have one side of the scale constantly being activated.
There are several reasons a person could have Th1 or Th2 dominance, including environmental factors and genetics . This explains why people have different types of immune systems – these things contribute to allergies, autoimmune disease, and more.
Conditions Associated with Th1 Dominance
The following are related to Th1 dominance, as determined through cytokine profiles and other scientific research.
- Organ-specific autoimmune disorders 
- Inflammatory Bowel disease (Crohn’s disease, ulcerative colitis) 
- Acute kidney rejection
- Type 1 diabetes 
- Multiple sclerosis ,
- Hashimoto’s Thyroiditis
- Rheumatoid Arthritis 
- Psoriasis, Rosacea
- Some unexplained recurrent abortions 
- Alzheimer Disease
- Low T3 syndrome  
- Guillain-Barre syndrome
Conditions Associated with Th2 Dominance
The following are related to Th2 dominance, as determined through cytokine profiles and other scientific research.
- Systemic autoimmune disorders 
- Systemic lupus erythematosus (SLE) 
- Progressive systemic sclerosis 
- Sjrogren’s syndrome (SS)
- Oral lichen planus
- Allergies  (hives, hay fever, nasal drip, mucus)
- Histamine intolerance 
- Airway constriction
- Atopic disorders
We Can Treat Th1 and Th2 Dominance
Emerging research has proven we can manage either case of Th1 or Th2 dominance. Certain foods, herbs and supplements can affect this immune balance. Click here to learn the ways we can impact Th1 and Th2 dominance.
About the Author
I'm Johann de Chickera, a Naturopathic Doctor, practicing in Ontario, Canada. My clinical practice relies on keeping up with the most up-to-date research and continued education. This blog serves as a way to provide others with a compilation of everything I've learned along the way. Please click here if you're local and want to see me in practice.