Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about B-cell and immunoglobulin disorders.

You can find written notes on this topic at zero-definals.com slash IG disorders

or in the immunology section of the Zero-definals pediatrics book.

So let's get straight into it.

B cells are responsible for producing antibodies,

an essential component of the specific immune system.

Abnormal B cells lead to a deficiency in antibodies or immunoglobulins. Deficiency in immunoglobulins is called

hypogamaglobulinemia. This leads to a susceptibility to recurrent infections, particularly lower

respiratory tract infections. Firstly, let's talk about selective immunoglobulin A deficiency.

And this is the most common immunoglobulin deficiency.

Patients have low levels of IGA and normal levels of IG and IGM and IGM.

IGA is present in secretions of the mucus membranes such as saliva,

respiratory tract secretions, gastrointestinal tract secretions, tears and sweat.

IGA protects against opportunistic infections of those mucus membranes.

Selective IGA deficiency is classed as a mild immunodeficiency.

Patients are often asymptomatic and never diagnosed.

Patients with IGA deficiency have a tendency to recurrent mucus membrane infections

such as lower respiratory tract infections and also autoimmune

conditions. Tom tip for you. The place you're likely to come across IGA deficiency is when

testing for celiac disease. The blood test for celiac disease are the IGA levels of anti-TTG and

anti-EMA antibodies.

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