Autoimmune disease occurs when an immune response attacks our own tissues. It is part of the adaptive immune response and involves T and B cell receptors. In contrast to infections, these cells recognise antigens that are processed from within the target organ.
What is autoimmune disease?
B cells produce antibodies targeting host cells, and active T cells recognise self antigens, a process which becomes amplified when they activate other immune cells. This triggers a chronic inflammatory process that disrupts normal tissue function.
In normal immune function, your body breaks down foreign substances (non-self antigens) using enzymes. If this system becomes overwhelmed and can’t break down non-self antigens effectively, your body then relies on antibodies which help transport these foreign substances for disposal.
In autoimmune conditions, your body mistakenly produces antibodies (autoantibodies) which act against the body’s own tissues, seeing them as foreign (self-antigens). These autoantibodies transport your body’s ‘self’ components for disposal, contributing to the autoimmune response.
Autoimmunity can be either organ specific or systemic. For example, type I diabetes is organ-specific and caused by immune cells erroneously recognizing insulin-producing pancreatic β cells as foreign, whereas systemic lupus erythematosus, commonly called lupus, antibodies recognize antigens expressed by nearly all healthy cells.
What causes it?
The trigger for this process often cannot be easily determined, however there are a few key potentials:
- Infection
- Environment
- Genetic (polymorphic genes)
A commonly accepted theory is that two simultaneous triggers are required: the primary lesion and immune dysregulation.
The primary lesion is the initial location of tissue damage caused by the autoimmune response. It represents the location where the immune system will first start to attack the body’s own tissues.
For example, in rheumatoid arthritis the damage begins in the synovial fluid of the joints and in multiple sclerosis it is the demyelination of the nerve fibres in the central nervous system. Immune dysregulation can be caused by infection, dysbiosis, leaky gut, chronic inflammatory conditions, insulin resistance, obesity, allergy, dietary or chemical sensitivity. All these conditions generate pro-inflammatory ‘danger’ signals that can disrupt healthy immune responses.
Your gut
As we discussed in previous editions, the gut is a crucial component of the immune system accounting for up to 80% of immune function. Microbial imbalance in the gut (dysbiosis) can be a known trigger to some autoimmune conditions. Supporting gut health and the microbiome is the first step in preventative care.