The link between Chronic Kidney Disease and Coeliac Disease

Coeliac Disease might not be one of the first things that come to mind when we hear the term “Chronic Kidney Disease”, but there are some interesting links between the two diseases, and the increasing incidence of Coeliac Disease globally makes this a topic worth discussing, especially for those of you who have been diagnosed with either disease or have a family history of them.

Coeliac Disease is on the rise…

The estimated rate of Coeliac Disease worldwide is 1%. That’s 1 in every 100 people. The fact that this rate is increasing and that there is a strong genetic link suggests that we can expect this figure to rise. The fact that we do not understand the mechanisms responsible for this increase means there is not a lot we can do at this stage to prevent it.

CD vs CKD…

Coeliac Disease is a complex and as yet not well-understood autoimmune disease, however, the predisposing factors are clear. Sufferers must experience a combination of genetic, immune and environmental factors for the disease to develop. It cannot develop without dietary exposure to the protein gluten, and can only be managed by removing this trigger.

Chronic Kidney Disease, although the majority of cases can be attributed to high blood pressure and diabetes, can develop as a result of many different factors, including autoimmune conditions, urinary tract infections, congenital malformations (meaning they are present at birth), physical obstructions of the urinary tract or prostatitis, and many other inflammatory and genetic conditions. Diet and nutrition can be of great benefit in reversing kidney disease as we know, but it is rarely the direct cause of the condition.

The conditions do not appear related do they? But a cohort study published by Nephrology Dialysis Transplantation, which investigated the link between any form of glomerulonephritis, dialysis treatment and kidney transplantation and Coeliac Disease, has found statistical significance associating CD with an increased risk of Glomerulonephritis and renal failure.

^{https://academic.oup.com/ndt/article/21/7/1809/1821933}

On the surface, the 2 diseases appear to be completely unrelated, so let’s look below the surface…

What are the links between the diseases?

In a nutshell, it appears that immune characteristics are at the core of the connection between these 2 common and very serious diseases.

There is currently a lot of scientific interest in the gut (our gastrointestinal tract), it’s mechanisms of immune regulation and the factors of modern life that present a threat to the delicate balance that it serves to maintain. In the gut resides the gut-associated lymphoid tissue, or GALT. This makes up around 70% of our body’s immune cells – 70%! If this balance is compromised, therefore, so is our immune system and its’ ability to protect us from disease. I will not go into too much depth about the role of GALT in this article, and to be honest there is still an awful lot we do not yet know about what goes on in there! But here is what we do know about the gut and the similarities that have been found between Coeliac Disease and Chronic Kidney Disease sufferers.

Activated Immune System 

The mucosal immune system exists in the lining of the gastrointestinal tract and serves as our first line of defence against harmful pathogens, just as our skin does. It is an entire ecosystem made up of a complex network of immune cells and beneficial bacteria. Like any ecosystem, it relies on adequate nutrition, hydration and other factors to thrive and maintain homeostasis, or ‘balance’. When this barrier is compromised, protective mechanisms are initiated, one of which is the production and secretion of Secretory Immunoglobulin A (IgA). Almost 100% of Coeliac Disease patients have these antibodies present, and it appears that this same mucosal immune mechanism is also active in many forms of glomerulonephritis.

^{https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2249.1992.tb07947.x}

^{https://www.frontiersin.org/articles/10.3389/fimmu.2016.00240/full}

Gut permeability 

Tight junctions are part of the structural component of the mucosal immune system in the gut wall. They prevent toxins and harmful bacteria from entering the blood stream. Essentially, it’s what separates our internal environment from the outside world, so it’s pretty important! If these tight junctions are damaged, unwanted pathogens enter the systemic circulation and cause inflammation and oxidative stress throughout the body. This has been linked, as both a cause and effect, to generalised autoimmune diseases including Coeliac Disease.

Studies have shown that a loss in kidney function can also reduce the effectiveness of the intestinal barrier, allowing pathogens to enter the bloodstream and potentially increase the decline of kidney function. Conversely, an impaired intestinal barrier can potentially lead to autoimmune kidney diseases in susceptible individuals due to the inflammation and oxidative stress caused by the failure of the body’s first line of defence.

Auto-antibodies 

What are auto-antibodies you ask? These are similar to the antibodies our immune systems produce to fight invading pathogens, but auto–antibodies are produced when the immune system mistakenly identifies its’ own tissue as the foreign invader. Auto = Self. This is what happens in autoimmune diseases. Being an auto-immune condition, auto-antibodies are raised in Coeliac Disease, and studies have shown the same auto-antibodies to be present in renal disease.

^{https://www.karger.com/Article/PDF/13497}

What are the main threats to our internal environment?

• Overuse of antibiotics and mediations
• Stress
• Chemicals in our food, water and environment
• Pathogenic bacteria from food water and the environment
• Poor diet
• Genetics
• Methods of birth and infant feeding

^{https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5483960/}

In Conclusion…

As with CD, the incidence of end-stage kidney disease is on the increase globally, the underlying causes of which are still largely unknown. Many other chronic, autoimmune and immune-related conditions are also on the rise. There are of course theories that speculate on this phenomenon, such as industrialisation, the hygiene hypothesis, overuse of antibiotics, the quality and preparation of the modern diet, stress and infections to name a few, but at the end of the day there are no definitive answers and therefore no definitive solutions.

With the growing body of evidence linking the gut to a myriad of health conditions, looking after our internal ecosystem seems like a pretty logical place to start in preventative health and disease management though. Don’t you agree?

^{https://www.worldgastroenterology.org/publications/e-wgn/e-wgn-expert-point-of-view-articles-collection/the-global-village-of-celiac-disease-and-its-evolution-over-time}