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Blood and immune system diseases

Common variable immunodeficiency (CVID)

A disease in which the immune system cannot make enough antibodies. Infections are frequent and keep coming back. Symptoms can begin in childhood or in adulthood.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Orphanet has a guideline for emergency doctors for this disease (language: French). See on Orphanet

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Blood and immune system diseases” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

Antibodies, which protect against germs, are made by white blood cells called B cells. In this disease, the B cells cannot produce enough antibodies. IgG and IgA, and sometimes IgM, are low in the blood. Because of this, the body has a hard time fighting infections.

Which symptoms can occur?

Symptoms vary greatly from person to person. They may include:

  • Frequent sinus, ear and lung infections (common)
  • Pneumonia, which is an infection of the lungs (common)
  • Long-lasting diarrhea and weight loss
  • Enlarged lymph nodes or spleen (sometimes)
  • The immune system attacking the body's own tissues, for example a drop in blood platelets (about 1 in 4)
  • Permanent lung damage over time

How is it diagnosed?

The diagnosis is usually made by an immunology specialist. Antibody levels are measured in the blood. Doctors check whether antibodies are formed in response to vaccines. A CT scan of the lungs is done, and in some people a genetic test as well.

Treatment and care

The main treatment is replacing the missing antibodies. This medicine is given regularly into a vein or under the skin. Many people learn to give the under-the-skin treatment at home. Infections are treated with antibiotics. Physiotherapy helps with lung problems. Regular blood tests are needed for follow-up. Vaccines should first be discussed with the immunology team. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

Most people have no other affected family members. The cause is often unknown; genes and the environment play a role together. In a small number of families, a change in a single gene is found. In that case, inheritance can be recessive or dominant. Genetic counselling helps to understand the risk in the family.

Source: MedlinePlus Genetics: Common variable immune deficiency · Immunodeficiency UK: Common variable immune deficiency disorders

Key facts

How common is it?
Prevalence: 1-9 per 100 000 (Worldwide)
When does it usually start?
Adolescence, Adulthood, Childhood

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about CVID

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

  • Could this trial be suitable for us?
  • If we take part, how would current treatment and check-ups be affected?
  • Where does the trial take place, and how are travel and accommodation handled?
  • What happens if we want to leave the trial?

ClinicalTrials.gov lists 11 active interventional studies for this disease. 6 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

See all studies on ClinicalTrials.gov · Joining clinical trials

Blood and immune system diseases: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:696851

No matching ICD-11 entry was found.

Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.