We all have heard about the age-old phenomenon of auto immunity wherein our body’s leukocytes attack the body’s own cells expressing some self antigens(auto antigens). So far, more than 100 types of autoimmune diseases have been identified, researched and managed. They are classified into Organ specific diseases like Graves’ disease affecting
Thyroid or Type 1 Diabetes Mellitus affecting Pancreas & Systemic diseases like Systemic Lupus Erythematosus and many more. While being researched a lot, many aspects of autoimmune diseases are still mysterious, little is known about them and that is what makes them interesting to researchers even now.
Our body, often correctly described as a nature’s marvel, has existing processes called self-tolerance in place. Tolerance is further divided into Central (occurring in primary lymphoid organs like bone marrow and thymus) and Peripheral (occurring in secondary lymphoid organs like lymph nodes,etc). Breakdown of these tolerance mechanisms(like anergy,
receptor editing, etc) generally accompanied with some other risk factors like susceptible genes, stress or infections trigger the initiation or an episode commonly called flare of autoimmune diseases. As complex as it sounds, there actually are many mechanisms through which autoimmune diseases manifest themselves in the human body, for egrelease of sequestered antigens, polyclonal B cell activation, inappropriate MHC class II expression and many more.
Diagnostic tests for autoimmune diseases include various markers and indices. Starting off with simple but non-specific indicators like increased CRP and ESR. Patients of chronic nature might also present with anaemia. Followed by, tests for estimating levels of autoantibodies (antibodies against self/auto antigens) which include non-specific ones like Anti Nuclear Antibodies(ANA), Anti-dsDNA, Anti-Sm antibodies and some specific ones like Anti TSH Receptor antibodies in Graves disease, Anti ACh Receptor antibodies in Myasthenia Gravis, etc.
According to an article by the Global autoimmune Institute, autoimmune disease rates have been rising for many decades and it is estimated from scientific literature that currently, 4% of the world’s population suffers from at least 1 autoimmune disease. A very significant reason for this increase in recent times is attributed to increase in diagnostic tests for
autoimmune diseases and heightened awareness among people about the same. In fact it is forecasted by the Global market Insights, that the Autoimmune Diagnostics Market is estimated to grow by 6.6% Compound Annual Growth Rate(CAGR) between 2022 to 2030.
Inflammation is a very broad term but it explains various risk factors and etiologies that contribute to autoimmunity. Anything ranging from stress to excessive pollutant exposure containing various aerosolized particles could be the cause of this inflammation which when persistent; leads to release of various inflammatory cytokines, these cytokines further recruit
leukocytes and the cycle of persistent inflammation continues. The universal problem of climate change has only added to the burden due to increased possibility of epigenetic modifications in immune cells as stated by a research article. Amongst some of the emerging environmental factors, ingestion and inhalation of microplastics has been studied and increase in its ingestion could directly be correlated with rise in autoimmune diseases.
An increase in infections (especially viral infections) is also causing an increase in autoimmune diseases by various mechanisms such as molecular mimicry- wherein the antibodies made against the pathogenic antigens start cross reacting with self antigens or by bystander T cell activation. In the COVID-19 pandemic, around 28 human proteins were
found to be homologous to the peptides of SARS-CoV-2 virus. These homologous proteins could function as autoantigens, hence triggering a myriad of autoimmune diseases.
The hygiene hypothesis which suggests that lesser exposure to infectious agents in childhood may pose a greater risk of autoimmune diseases in the future, that is decreased frequency of infections poses threat of increased incidences of autoimmune diseases. Many articles have also suggested that increased consumption of western diet (so called fast foods which contains high amount of fats, salt and sugar) also might be a reason for the increase as, they may lead to obesity which is a risk factor plus they also alter the gut microbiome which is an important site of self tolerance. Last but not the least genetic factors also make some individuals more susceptible to some autoimmune diseases.
According to a 2021 news report, 1.3 crore people in India suffer from rheumatoid arthritis, which usually present with vague symptoms that need to be differentiated from other types of inflammatory arthritis. Even the type, number and pattern of joint involvement varies from person to person hence, the 2010 ACR/EULAR criteria defines a scoring system which takes into account 4 domains namely joint involvement, serology, duration of symptoms and acute phase reactants.
The incidence rate of Multiple Sclerosis, a chronic inflammatory demyelinating disorder affecting the nervous system has also doubled according to an epidemiology study. Many researchers have claimed the relation between vitamin D deficiency and MS, although there is an interplay of various genetic and environmental factors; no particular aetiology has been
established yet. The National MS Society states that the possible reasons for increasing cases is likely due to better access to medical care and improved diagnostic capabilities.
Treatments for autoimmune diseases generally involve suppressing the overactive immune system causing overt inflammation by using drugs like corticosteroids which in general act to suppress all stages of inflammation, immunomodulators which target specific points in the immune response and painkillers for symptomatic relief. These treatments mainly aim at reducing progression of the disease and also provide symptomatic relief.
Many studies show that there is decreased risk of developing an autoimmune disease by ensuring adequate intake of certain nutrients like vitamin D, C, omega-3 fatty acids, etc although this is not backed by enough evidence yet but so far it is the one of the few methods which can be used for prevention. Gut microbiome, rightly called as the 2nd genome of the human body is of utmost importance in maintaining an overall balance of the immune system, thus ensuring a healthy gut and using probiotics definitely aid in autoimmune disease prevention.
In conclusion, autoimmune diseases as such have vague symptoms like frequent muscle aches, low grade fever, etc and varying types of progression in different people which is why ever changing and exhaustive diagnostic criteria’s are laid out taking into account symptoms, clinical findings and radiological details.
References
https://www.gminsights.com/industry-analysis/autoimmune-disease-diagnostics-market
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2832720/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2832720/
https://www.nature.com/articles/nri.2017.111
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4034518/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604700/
https://www.nationalmssociety.org/What-is-MS/Who-Gets-MS
