I’ve recently come across an info-graphic on Twitter, claiming that interstitial cystitis (IC) is an autoimmune condition where the immune system attacks the bladder lining, causing the painful symptoms of IC. This reminded me that it’s about time that I explore this question further: Is interstitial cystitis an autoimmune condition or not?
The short answer is: maybe sometimes.
What Is Autoimmunity?
The immune system is the body’s defence mechanism against foreign intruders, such as pathogens.
It has different mechanisms of defence:
- Innate immunity (inborn), which is non-specific and uses barriers, anti-microbial fluids and a non-specific immune response to ward off intruders.
- Acquired immunity, which uses proteins called ‘antibodies’ that are specific for certain pathogens and help to destroy them. These antibodies are usually formed during an infection and once they are present, protect us from subsequent infections with the same pathogen.
In autoimmunity, the immune system mistakenly recognizes our own body tissues as an invader and the latter mechanism goes awry and antibodies (called auto-antibodies) are formed against certain body tissues.
These auto-antibodies then launch attacks against a particular body tissue when triggered, leading to inflammation and damage, which over time compromises the health of the affected area.
For example, in Hashimoto’s Thyroiditis or Grave’s disease the immune system produces antibodies against thyroid tissue. When triggered, these antibodies mount an attack against thyroid tissues, damaging the organ so that over time output of thyroid hormones is reduced, leading to symptoms of low thyroid activity.
To give another example, in rheumatoid arthritis the immune system attacks connective tissue and cartilage in joints, leading to inflammation, pain and stiffness.
The Theory behind IC as an Autoimmune Condition
In a model of autoimmune interstitial cystitis, the above process would apply to the bladder.
The immune system would produce antibodies to the tissue of the bladder lining, attacking it when triggered.
Over time, this could lead to inflammation and pain in the bladder and other symptoms associated with IC.
Damage to bladder tissue could also result in lesions, such as experienced in IC with Hunner’s lesions (a.k.a Hunner’s ulcers).
What does the Evidence say?
The idea of IC being an autoimmune condition still seems to be controversial. But some evidence points to the fact that the idea can’t be completely dismissed.
The reason why autoimmunity has been suggested as a possible root cause, is that sufferers of IC are predominantly female and that there is often an overlap with other autoimmune disorders, such as Lupus or Sjoergen’s .
When mice were artificially put into a state of bladder autoimmunity, they developed symptoms that were consistent with the clinical features of IC [2, 3], plus increased mast cell counts and activation in the bladder . Now this doesn’t proof that IC is autoimmune in nature but rather that autoimmunity is capable of producing the symptoms of IC.
Some more solid findings support the potential for autoimmunity:
- Some cases of IC with Hunner’s lesions have shown increased ‘clonal expansion of B-cells’ – B-cells are immune cells and their clonal expansion is associated with autoimmunity [1, 5]. However, clonal B-cells can also be a result of bacterial or viral infections , therefore they could be a marker of hidden infections rather than autoimmunity.
- IC with Hunner’s lesions has been associated with an up-regulated expression of a genetic pathway (called CXCR3) associated with allergic and autoimmune conditions .
- In one study, 36% of IC sufferers showed auto-antibodies in blood tests that looked different to auto-antibodies associated with other conditions and therefore may be specific for the bladder .
As you will hopefully have gathered from the above information, there is no conclusive evidence that IC is an autoimmune condition.
However, in some cases it may have an autoimmune component, which seems to be more likely in IC with Hunner’s lesions.
This shows once again that rather than one cause, there may be several causes of IC capable of causing the same symptoms.
Now I’d like to hear from you: Do you suffer from several autoimmune disorders and think your IC may be connected? Let me know in the comments!
Pin it for later:
- Maeda, Daichi et al Hunner-Type (Classic) Interstitial Cystitis: A Distinct Inflammatory Disorder Characterized by Pancystitis, with Frequent Expansion of Clonal B-Cells and Epithelial Denudation Plos One November 20, 2015https://doi.org/10.1371/journal.pone.0143316 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0143316
- Luber-Narod, J. Experimental autoimmune cystitis in the Lewis rat: a potential animal model for interstitial cystitis et al. Urol. Res. (1996) 24: 367. https://doi.org/10.1007/BF00389795 https://link.springer.com/article/10.1007%2FBF00389795?LI=true#citeas
- Izgi, Kenan et al Uroplakin Peptide-Specific Autoimmunity Initiates Interstitial Cystitis/Painful Bladder Syndrome in Mice Plos One August 16, 2013https://doi.org/10.1371/journal.pone.0072067 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0072067
- Bicer, Fuat et al Chronic pelvic allodynia is mediated by CCL2 through mast cells in an experimental autoimmune cystitis model Renal Physiology [Volume 308, Issue 2, January 2015, Pages F103-F113] http://www.physiology.org/doi/abs/10.1152/ajprenal.00202.2014
- Akiyama, Y. et al. Increased CXCR3 Expression of Infiltrating Plasma Cells in Hunner Type Interstitial Cystitis. Rep. 6, 28652; doi: 10.1038/srep28652 (2016). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4919639/
- Ochs, R. et al Autoantibodies in interstitial cystitis. J Urol. 1994 Mar;151(3):587-92. https://www.ncbi.nlm.nih.gov/pubmed/8308964