Autoimmune diseases occur when there is an attack on body’s own cells by immune system. Generally, immune system helps body fight foreign bodies/infections such as viruses, bacteria and fungi, but due to various factors such as genetics, age and environment the immune system produces antibodies against its own cells.
There are over 80 identified autoimmune diseases and the examples of common autoimmune diseases include lupus, Sjogren’s syndrome, Grave’s disease, rheumatoid arthritis, inflammatory bowel disease, Hashimoto’s thyroiditis, vitiligo, psoriasis, type 1 diabetes, multiple sclerosis and Myasthenia gravis. Either these pathogens (mostly bacteria and viruses) lead to autoimmunity due to damage of immune system or there is production of certain elements by pathogens that resemble the host cells due to which immune system also attacks normal host cells due to its resemblance to foreign cells.
What Infections Cause Autoimmune Diseases?
The Most Common Autoimmune Diseases Associated To Infections Include:
-Type 1 diabetes is associated with coxsackievirus B4, cytomegalovirus (CMV), mumps, and rubella virus.
-Rheumatoid arthritis is associated with Epstein Barr virus (EBV), hepatitis C virus, mycobacteria and Escherichia coli bacteria.
-Multiple sclerosis is related to infection by Epstein Barr virus, cytomegalovirus and measles virus.
-Lupus is associated with Epstein Barr virus.
-Guillain-Barre syndrome is thought to be caused by Epstein Barr virus, cytomegalovirus and Campylobacter bacteria.
-Myasthenia gravis is associated with herpes simplex virus and hepatitis C virus.
-Myocarditis is associated with Chlamydia bacteria, cytomegalovirus and coxsackievirus B3.
Epstein Barr Virus
EBV is a very common infection and belongs to herpes family of viruses. It causes glandular fever/mononucleosis. It is thought to be a trigger for about 33 different autoimmune diseases. Epstein Barr virus is linked with the development of rheumatoid arthritis, multiple sclerosis, Guillain-Barre syndrome, systemic lupus erythematosus and Sjogren’s disease.
This virus also belongs to the family of herpes virus and is an extremely common infection. Patients are usually symptom less when infected with this virus, so they are unaware of their condition. With weak immune system, symptoms such as sore throat, mild fever and mild hepatomegaly are present. Cytomegalovirus increases the risk of developing type 1 diabetes, myocarditis, multiple sclerosis and Guillian-Barre syndrome.
Herpes Simplex Virus
This virus is associated with herpetic stromal keratitis (HSK) that may lead to blindness. HSK symptoms are alleviated by immunosuppressants, thus indicating involvement of immune system. However, most of the studies are done in murine samples due to difficulty in studying in humans.
This virus is mostly associated with infectious myocarditis as viral RNA has been isolated from patients heart. However, these are studied in infected mice and there is uncertainty about the disease pathology in humans. Coxsackievirus B is also associated with developing autoimmunity in type 1 diabetes.
Streptococcal infection is a very common infection, mostly associated with strep throat that has symptoms of sore throat, fever and cervical lymphadenopathy. Although, sore throat is a viral infection, but patients can have secondary strep bacterial infection. Strep infection is also associated with rheumatic fever autoimmune disease that involves joints (arthritis), heart (myocarditis), skin (rashes) and brain (Sydenham chorea in which there is involuntary movement of facial muscles, arms, legs and trunk). Streptococcus is also considered a trigger for autoimmune glomerulonephritis, Tourette syndrome and pediatric autoimmune neuropsychiatric disorder associated with Streptococcal infections (PANDAS).
H. pylori is associated with increased risk of stomach ulcers and stomach cancers. It is mostly found in gut and leads to gastritis causing symptoms of heartburn, bloating, nausea, stomach pain and burping. This bacterium is associated with rheumatoid arthritis, psoriasis, systemic sclerosis, sarcoidosis, thrombocytopenia, atherosclerosis and antiphospholipid syndrome.
This virus is related to stomach flu (viral gastroenteritis) that has symptoms of nausea, vomiting, diarrhea and stomach pain with low-grade fever, muscle pain and headache. Norovirus is associated with the development of Crohn’s disease.
This tick borne spirochete is responsible for Lyme disease in the US and 60% untreated cases may develop arthritis and progress to chronic Lyme arthritis that may be antibiotic resistant and even develop Central Nervous System complications.