IgG4-associated Autoimmune Diseases Explained

IgG4-associated Autoimmune Diseases Explained

According to abbreviationfinder, IgG4-associated autoimmune diseases are a group of diseases in which the immune system attacks the body’s own tissues. The diseases are among the systemic diseases and can affect several organ systems at the same time or one after the other. In the meantime, the administration of glucocorticoids has become commonplace for the symptomatic treatment of diseases that were previously incurable.

What are IgG4-associated autoimmune diseases?

In acute situations such as loss of consciousness, an ambulance must be called. First aid measures are necessary to ensure the survival of the person concerned until it arrives.

The human immune system recognizes pathogens and other foreign bodies that have penetrated the human organism. After identification, the cells of the immune system attack the foreign bodies in order to eliminate them and thus protect the organism. In autoimmune diseases, the immune system mistakenly recognizes the body’s own tissue as foreign and attacks healthy cells of its own organism.

The so-called IgG4-associated diseases are a group of autoimmune diseases. These are system diseases that can in principle be directed against all tissues and organs of the body. IgG4-associated autoimmune diseases cause severe swelling and fibrosis and are immune-mediated.

The group consists of chronic diseases with an increase in antibody-producing IgG4-positive plasma cells. The clinical picture of IgG4-associated autoimmune diseases can differ significantly from case to case. IgG4-associated diseases are particularly widespread in East Asia and primarily affect middle-aged to older men. The most well-known IgG4-associated disease is IgG4-associated pancreatitis or autoimmune pancreatitis type 1.


As with all other immune diseases, the cause of IG4-associated immune diseases has so far been controversial. Many researchers are now assuming an independent mechanism of formation. According to scientists, the so-called “cross-talk” between the innate and acquired immune system is disturbed in patients in the disease group.

The so-called Th2 reaction of the immune system seems to play a central role in the pathogenesis of the diseases. The reaction activates the regulatory T-lymphocytes and stimulates the formation of transforming growth factor ß and interleukin 10. These substances in turn stimulate the body to form IgG4. The triggering mechanism for the Th2 reaction is not yet known.

Some authors speak of autoantigens while others discuss infectious agents. According to current knowledge, autoantibodies against prohibitin are present in the majority of all patients. This connection speaks for a purely autoimmune genesis of most of the IgG4-RD groups.

However, not every IgG4 patient is affected by an autoimmune disease. To put it better, it remains largely unclear whether an increase in IgG4 is the cause of the development of the disease or occurs as an epiphenomenon after the development of the disease.

Symptoms, Ailments & Signs

The symptoms of an IgG4-associated autoimmune disease differ from case to case and mainly depend on the exact disease. Apparently, IgG4-RD often manifest themselves in different organs or tissue systems at the same time or in quick succession. For this reason they are called systemic diseases.

The degree of organic dysfunction depends on the individual case. In principle, the enlargement or swelling of the affected organs and tissues is the common feature of all IgG4-associated autoimmune diseases. In most diseases of the group, severe scarring occurs in the sense of sclerosing of the tissue.

Compression of ducts has been observed primarily in diseases such as Miculicz syndrome, sclerosing cholangitis and Ormond’s disease. This phenomenon entails a stagnation of secretion, which is often associated with subsequent symptoms. More than a dozen different diseases are now classified as IG4-associated autoimmune diseases. With some diseases from the group, slight pain symptoms can occur in the affected tissues.

Diagnosis & course of disease

As part of the diagnostics, organic examinations of various organs and tissues of the body must be carried out to detect IgG4-associated diseases. Only when several organ systems are affected, for example when the lungs, kidneys, liver or pancreas are affected in combination, can we speak of an IgG4-associated disease.

Laboratory values ​​and imaging are part of the standard diagnostics. A histology is also required in most cases. The prognosis for patients with IgG4-associated autoimmune diseases is relatively unfavorable due to the susceptibility to secondary diseases. Apparently diseases of the group increase the risk of tuberculosis and cancer.

The chronicity of IgG4-associated diseases is also associated with poor prospects. Regularly affected tissue may suffer irreversible damage. This circumstance is particularly unfavorable in the case of the infestation of organs.


IgG4-associated autoimmune diseases can lead to serious damage and complications to the organs, which can also be life-threatening for the patient. This can reduce life expectancy if the disease is not treated immediately. However, it cannot be predicted which organs will be affected and how the symptoms will manifest themselves.

In most cases, however, the organs enlarge and cause pain. They can also swell and cause scars. It is not uncommon for there to be damage to the patient’s skeleton and stabbing pain. The sufferer generally feels ill and suffers from low resilience. The muscles often hurt and movement is restricted.

In most cases, the treatment of IgG4-associated autoimmune diseases is only symptomatic, as causal treatment is not possible. Drugs are administered to the patient and no further complications arise. However, complications can arise if organs have been irreversibly damaged. In this case, death occurs or a transplant is necessary to keep the patient alive.

When should you go to the doctor?

Swelling on the body and diffuse skin changes should be presented to a doctor. If there is a feeling of tightness inside the body, if the skin abnormalities spread further or if you feel unwell, a doctor is needed to clarify the symptoms. In the event of malfunctions in individual systems or a general feeling of illness, a doctor’s visit is necessary.

In acute situations such as loss of consciousness, an ambulance must be called. First aid measures are necessary to ensure the survival of the person concerned until it arrives. A doctor must be consulted in the event of pain, a drop in performance, difficulty concentrating, dizziness or sleep disorders. If you experience unsteady gait, headaches, bleeding, stomach problems, diarrhea or constipation, you should consult a doctor.

If cramps set in or if you notice any psychological abnormalities, you should see a doctor. Difficulty urinating, difficulty breathing, or pauses in breathing should be evaluated and treated. If the person affected suffers from mobility disorders, joint problems or significant changes in weight, a doctor should be consulted. In the event of changes in the heart rhythm, high blood pressure or circulatory disorders, a doctor’s visit is necessary. Repeated vomiting, nausea and sputum production are considered unusual and should be examined by a doctor. If there is no cold, a doctor should be consulted as soon as the symptoms persist for several days.

Treatment & Therapy

There is sometimes no causal treatment for patients with IgG4-associated autoimmune diseases because the cause has not yet been finally clarified. Therapy is therefore exclusively symptomatic. In other words, diseases of this group are not curable up to the present time.

Experience has shown that glucocorticoids have become established for the symptomatic treatment of patients with IgG4-associated diseases. If there is intolerance to steroids or a steroid-refractory course, rituximab can be administered. The drug quickly leads to an improvement in clinical and histological findings.

The B cells in the patient’s tissues decrease. The same applies to the IgG4 concentration in the serum of the person concerned. It is important to have a reliable diagnosis before administering medication. Lymphoma diseases in particular must be ruled out in the differential diagnosis before therapy is started.

Other treatment options have not been documented to date. Especially in the case of IgG4-associated autoimmune pancreatitis, an excellent response to glucocorticoids was reported in the majority of all cases. Irreversible damage to organs may have to be compensated for with an organ transplant.

Outlook & Forecast

According to current scientific and medical knowledge, IgG4-associated autoimmune diseases are incurable. The prognosis is therefore described as unfavorable. Nevertheless, there are therapeutic approaches that alleviate individual symptoms and thus contribute to an improvement in the quality of life. The chronic diseases have a strong impact on those affected. In addition to various dysfunctions and pain, there is also a risk of life-threatening courses. If organs are affected, the prognosis worsens significantly. The life expectancy of these patients is usually shortened because irreparable damage occurs.

Alternatively, organ transplants can be performed as a life-prolonging measure. If a donor organ is available, this route is often chosen. The surgical procedure is associated with risks and side effects. If no complications occur and the donor organ is accepted by the organism, the patient normally experiences an improvement in his health.

If the operation is unsuccessful, the symptoms increase and the general condition is severely weakened. When an organ is enlarged, there is often severe pain. As a result, the patient has to undergo long-term therapy. As soon as the treatment is stopped, the symptoms regress. Permanent relief is currently not possible, as no exact cause for the development of the autoimmune diseases could be found. The treatment of the individually occurring symptoms is the focus of medical care.


The causes and the detailed pathogenesis of IgG4-associated diseases have not yet been conclusively elucidated. As long as the causes of the diseases are unclear, there will be no promising ways of preventing them. This connection not only characterizes IgG-associated autoimmune diseases, but also applies to almost all autoimmune diseases to this day.


IgG4-associated autoimmune diseases can only be treated to a limited extent in follow-up care. As with almost all autoimmune diseases, there are only a few rough guidelines for prevention. Doctors first recommend an anti-inflammatory diet with foods that strengthen the body. This is followed by a healthy lifestyle with sufficient exercise.

The focus is on the mindfulness of the patients, who should be aware of themselves and their way of life. With physical activity, the risk of inflammation is reduced, while at the same time your own body awareness improves. Avoiding certain foods reduces the risk of inflammation. Food of animal origin such as meat can have a harmful effect.

High-sugar foods and arachidonic acid, found in red meat, for example, increase inflammation. Therefore, those affected should limit the consumption of meat and refined sugar. Legumes, vegetables, nuts, fruit and linseed oil are suitable anti-inflammatory drugs. Omega-3 fatty acids and many spices also ensure a stronger immune system.

Those affected can exchange ideas directly in self-help groups or take part in an online forum. Here they meet understanding and get used to their new life situation. This communication helps in day-to-day management of the immune disease.

You can do that yourself

Those affected exchange information in various self-help groups or forums on the Internet. The often long way to the diagnosis is a burden. Every patient has to find their own way of dealing with the changed life situation. Sharing experiences and recognizing parallels are positive aspects of coping.

An anti-inflammatory diet helps many patients. Numerous foods have a positive effect on inflammatory processes in the body. The quality of life increases through a healthy lifestyle. In addition to nutrition, this also includes taking care of yourself. Sport also has an anti-inflammatory effect and increases well-being.

A first step is to avoid foods that increase inflammation. Meat and animal foods contain arachidonic acid. This fatty acid promotes inflammation, as does refined sugar. On the other hand, vegetables, legumes, fruit, nuts, berries, linseed oil and rapeseed oil have an inhibiting effect. The occurrence of inflammatory processes and chronic inflammation is reduced by eating tomatoes, cherries, papaya, blueberries, pomegranate seeds or pomegranate juice, pineapple, spinach, carrots, watermelons, white cabbage, lamb’s lettuce and omega-3 fatty acids, for example in wild salmon.

Spices such as turmeric, ginger, chilli, oregano and cinnamon also have health-promoting effects. Also garlic and onions. Poultry is an alternative to red meat. This also applies to fatty sausages. Sugar can be replaced with honey, agave syrup or raw cane sugar.

IgG4-associated Autoimmune Diseases