IgA Deficiency

#med #disease #y2023

Presentation :

Most common primary antibody deficiency, although most patients remain asymptomatic
Presents with recurrent infections of mucosal surfaces, most commonly sinus/upper/lower respiratory tract and less frequently, gastrointestinal tract
- Particularly vulnerable to encapsulated bacteria like Streptococcus pneumoniae and Haemophilus influenzae
- Also vulnerable to recurrent Giardia infection
Anti-IgA IgE antibodies can rarely cause anaphylaxis to blood products (no exposure, no tolerance); however, transfusions can be given with close monitoring.
The inheritance pattern is unknown, but having a family member with selective IgA deficiency increases the risk by about 50 times.

IgA provides mucosal immunity; therefore, patients are susceptible to infections of the mucosal surfaces of the respiratory and gastrointestinal tracts

Defined by an IgA level < 7 mg/dL with normal IgG and IgM levels
Testing of family members is not recommended because most patients with low IgA have no clinically significant manifestations
- However, patients who have a history of transfusion-related reactions should be tested for IgA deficiency, particularly if they have a family member with IgA deficiency.

- Some patients develop Common Variable Immunodeficiency (CVID) over time, and some remit spontaneously