Selective Immunoglobulin A Deficiency – Causes, Symptoms & Treatment

Selective immunoglobulin A deficiency

The term selective immunoglobulin A deficiency refers to a congenital immune defect. The absence of immunoglobulin A, a specific class of antibodies, is characteristic of selective immunoglobulin A deficiency. Affected people can lead a symptom-free life, although they develop respiratory infections more frequently than people who do not suffer from selective immunoglobulin A deficiency.

What is selective immunoglobulin A deficiency?

Selective immunoglobulin A deficiency is a congenital immunodeficiency . The defect is characterized by the absence or reduction of immunoglobulin A, while all other immunoglobulin isotypes correspond to the norm. Selective immunoglobulin A deficiency is one of the most common immunodeficiencies, with ethnic background playing a major role.

While the frequency in the Arabic region is 1:142, the probability in Japan is 1:18,500. While selective immunoglobulin A deficiency is a fairly common disease in Africa and the western world, the exact opposite is the case in Asia.


So far, the cause of selective immunoglobulin A deficiency is not known. However, the deficiency results from a lack of maturation or a lack of production of immunoglobulin A in the B cells. The selective immunoglobulin A deficiency is further differentiated into IgA1 and IgA2. Doctors call IgA1 the monomore immunoglobulin (the circulating serum) and IgA2 the dimeric immunoglobulin (the secretory immunoglobulin).

Sometimes drugs – including phenytoin and penicillamine – as well as infections (such as the Epstein-Barr virus or congenital rubella ) can also trigger acquired selective immunoglobulin A deficiency. Other causes or contributing factors have not yet been confirmed.

Symptoms, Ailments & Signs

The severity of selective immunoglobulin A deficiency is extremely variable and individual. More than 50 percent of all those affected are free of symptoms. This is because the function of the missing immunoglobulin A is replaced by immunoglobulin B present in the mucous membranes. However, 30 percent of patients suffer from recurring respiratory infections . In rare cases, patients complain of complaints that primarily affect the digestive system.

Sometimes autoimmune or tumor diseases as well as allergies can also occur, which are connected to the selective immunoglobulin A deficiency. The following symptoms and diseases are therefore possible – in the context of a selective immunoglobulin A deficiency: infections ( bronchitis , pneumonia , sinusitis ), autoimmune diseases ( lupus erythematosus , celiac disease , Crohn’s disease and rheumatoid arthritis ) .

Ulcerative colitis and allergies such as atopy , food intolerance and allergic bronchial asthma can also trigger selective immunoglobin A deficiency, as can tumor diseases ( thymomas , lymphomas, tumors of the digestive system, lung tumors and stomach cancer ) and problems with the digestive system ( diarrhoea ) . .

Selective immunoglobulin A deficiency manifests primarily through deficiency-related disorders, but not with specific symptoms and conditions caused by the deficiency.

Diagnosis & disease progression

Based on the repeated determination of the immunoglobulin A concentration, the doctor can make the diagnosis of selective immunoglobulin A deficiency. Patients suffering from selective immunoglobulin A deficiency have an extremely low level of immunoglobulin A, which is below 0.3 g/l. The two subclasses IgA1 and IgA2 are predominantly affected, while the value of IgM is normal.

Any other immunodeficiencies as well as secondary immunoglobulin A deficiency must be ruled out before the diagnosis of selective immunoglobulin A deficiency is made. Often the diagnosis is based on the process of elimination; this means that all other possible diseases were ruled out, so that the diagnosis of selective immunoglobulin A deficiency could be made.

Patients suffering from selective immunoglobulin A deficiency have a normal life expectancy. The prognosis, as well as the course of the disease, is favorable in the absence of other diseases. If selective immunoglobulin A deficiency is diagnosed in children, there is a possibility that the deficiency will regress. Sometimes, however, selective immunoglobulin A deficiency can also lead to CVID; the prognosis is less favorable here. As with the symptoms, the course of the disease is individual and variable, so that no precise predictions and prognoses can be made.


This disease does not always lead to serious symptoms or complications. Often, those affected can lead an ordinary life, although they are more likely to suffer from respiratory diseases. These infections are relatively common and can reduce quality of life. Digestive problems can also occur with this deficiency, so that pain in the abdomen or stomach can occur.

Furthermore, the disease can lead to the formation of tumors. Those affected often also suffer from intolerance to various foods and just as often from diarrhea or tumors in the stomach and intestines. In many cases, the disease is not recognized until late because the symptoms are not particularly characteristic and do not immediately indicate the disease.

For this reason, treatment is usually delayed. The treatment itself is usually carried out with the help of medication or blood transfusions. There are no complications. However, the complaints cannot be completely limited. The life expectancy of the patient may also be reduced due to the illness.

When should you go to the doctor?

Selective immunoglobulin A deficiency is an immune defect that is congenital. In this respect, there is a certain probability that this will be discovered early. The problem, however, is that this immune deficiency often shows only mild symptoms. So far there is no causal treatment option.

Those affected lack immunoglobulin A, a specific type of antibody. The absence of this antibody does not cause any symptoms in half of those affected. In other people affected, there is an accumulation of respiratory infections. It is also precarious that the selective immunoglobulin A deficiency can lead to further secondary diseases. Examples include diseases of the digestive system, autoimmune diseases such as celiac disease, Crohn’s disease or lupus erythematosus. In addition, the selective immunoglobulin A deficiency can lead to food allergies to milk protein, atopy or allergic bronchial asthma.

The tendency for certain tumor diseases is increased in many of those affected. If there is a selective immunoglobulin A deficiency, other immunodeficiencies must first be ruled out. It is therefore advisable to go to the doctor in the event of persistent immune problems or infections and to point out the immune deficiency problems.

In the case of selective immunoglobulin A deficiency, an infusion with immunoglobulins is counterproductive. This can lead to severe allergic sequelae because the injected substance is perceived by the organism as unknown and hostile. Blood transfusions can also trigger dangerous reactions. An emergency card is therefore recommended for those affected whose diagnosis is confirmed.

Treatment & Therapy

Treatment is primarily based on relieving the symptoms and discomfort. There is no so-called cause treatment. Patients who are free of symptoms therefore do not require any treatment or therapy; the majority, i.e. more than 50 percent of all those affected, are therefore not receiving medical treatment and therefore do not feel any restrictions in their lives.

If infections occur that are associated with selective immunoglobulin A deficiency, the viruses or pathogens must be treated and combated. Doctors usually prescribe antibiotics here . Sometimes prophylactic antibiotic therapy can also be used so that any recurring infections can be fought and prevented in advance.

Intravenous infusions of immunoglobulins do not usually occur; Namely, patients suffering from selective immunoglobulin A deficiency produce antibodies themselves, which – if immunoglobulins are added – can lead to allergic reactions when immunoglobulins are transferred. For this reason, selective immunoglobulin A deficiency is the most important contraindication for any IVIG therapy.

For this reason – with blood transfusions – there is a risk that allergic reactions will also be triggered. For this reason, people suffering from selective immunoglobulin A deficiency are recommended to always have their emergency card with them and to inform the doctor if any interventions are planned. Other therapies or treatment options are currently not available or are not used.


Selective immunoglobulin A deficiency cannot be prevented. Since it is a congenital immune defect, although the cause has not yet been fully clarified, the disease cannot be prevented.


In the case of the immunodeficiency of selective immunoglobulin A deficiency, follow-up care is limited to symptomatic therapy. Due to the increased risk of infection, the aftercare here mainly includes the treatment and alleviation of any infections that may arise, especially of the respiratory tract and, more rarely, of the digestive system, with the help of antibiotics. In some cases, prophylactic therapy with antibiotics is also necessary for a longer period of time.

It is important here that the patient is aware of the increased risk of respiratory infections and tries to treat pathogens in a timely and targeted manner with medical help. With this disease there is also an increased risk of developing tumors or autoimmune diseases such as Crohn’s disease or rheumatoid arthritis.

There is also the possibility of developing allergies and also food intolerances, which can often be alleviated by a specific diet. Therefore, regular check-ups after diagnosis are necessary to monitor this. Because of the risk of allergic reactions from blood transfusions, the person with selective IgA deficiency should carry an emergency medical card.

Selective immunoglobulin A deficiency cannot be cured. However, most of the sick people can live almost symptom-free and life expectancy is normal or only slightly reduced.

You can do that yourself

The problems caused by selective immunoglobulin A deficiency can be reduced with prophylactic measures. In everyday life, the targeted fight against pathogens reduces the risk of respiratory infections, asthma and eczema. The congenital disease often leads to infections, which is why it is of great importance for those affected to treat the pathogens in a timely and targeted manner.

When taking antibiotics, patients should follow the doctor’s prescription exactly. Medication is now used as a preventive measure to keep the symptoms as low as possible. Because it is a genetic disease, there are limits to pharmacological therapy. For those affected, this means that they have to be particularly careful in certain situations.

If a blood transfusion occurs, there is a risk of an allergic reaction. For this reason, it is advisable for the persons concerned to carry their emergency ID card with them at all times. In the event of an emergency or intervention, the doctors know immediately about the deficiency disease and can take appropriate precautionary measures. For the patients themselves, it makes sense to act in good time in the event of an infection or other illnesses in order to prevent complications. A trusting relationship with the family doctor helps.

Lisa Newlon
 | Website

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.