Common variable immunodeficiency

A primary immunodeficiency disorder

Common variable immunodeficiency (CVID) is a primary immunodeficiency disorder characterized by low levels of serum immunoglobulins and an increased susceptibility to infections. It is one of the most frequently diagnosed primary immunodeficiencies and can present at any age, although it is most commonly diagnosed in adults.

Pathophysiology

CVID is a heterogeneous disorder with a complex pathophysiology. It involves defects in the B cell differentiation process, leading to impaired production of immunoglobulins (antibodies). This results in decreased levels of IgG, IgA, and sometimes IgM. The exact genetic causes of CVID are not fully understood, but mutations in several genes, including TNFRSF13B (TACI), have been implicated.

Clinical Features

Patients with CVID typically present with recurrent infections, particularly of the respiratory tract, such as sinusitis, bronchitis, and pneumonia. They may also experience gastrointestinal infections and chronic diarrhea. In addition to infections, individuals with CVID are at increased risk for autoimmune disorders, granulomatous disease, and certain types of cancer, particularly lymphoma.

Diagnosis

The diagnosis of CVID is based on clinical presentation and laboratory findings. Key diagnostic criteria include:

• Low levels of serum IgG, IgA, and/or IgM
• Poor response to vaccines
• Exclusion of other causes of hypogammaglobulinemia

Additional tests may include assessment of B cell numbers and function, as well as genetic testing to identify potential mutations associated with the disorder.

Treatment

The mainstay of treatment for CVID is immunoglobulin replacement therapy, which helps to reduce the frequency and severity of infections. This can be administered intravenously (IVIG) or subcutaneously (SCIG). In addition to immunoglobulin therapy, patients may require antibiotics to treat or prevent infections. Management of associated autoimmune or inflammatory conditions may involve the use of immunosuppressive medications.

Prognosis

The prognosis for individuals with CVID varies depending on the severity of the condition and the presence of complications. With appropriate treatment, many patients can lead relatively normal lives, although they may still experience recurrent infections and other health issues.

Related pages

• Primary immunodeficiency
• Immunoglobulin therapy
• Autoimmune disease
• Lymphoma