How is XLA diagnosed?

Clinical history and physical examination

The diagnosis of acute X-linked agammaglobulinemia (XLA) is based on the clinical history and physical examination findings. The most common clinical features of XLA include:

* Recurrent infections, such as pneumonia, bronchitis, sinusitis, and ear infections

* Failure to thrive

* Diarrhea

* Weight loss

* Skin rashes

* Swollen lymph nodes

* Splenomegaly

* Hepatomegaly

Laboratory findings

The laboratory findings that suggest XLA include:

* Low levels of immunoglobulins (IgG, IgA, and IgM)

* Absence of B cells in the peripheral blood

* Normal or elevated levels of T cells in the peripheral blood

* Bone marrow findings that show a lack of B cells

Genetic testing

Genetic testing can confirm the diagnosis of XLA. Genetic testing can identify the specific mutation in the Bruton's tyrosine kinase (BTK) gene that causes XLA.

Other diagnostic tests

Other diagnostic tests that may be helpful in diagnosing XLA include:

* X-ray of the chest

* CT scan of the chest and abdomen

* MRI of the brain

* Sweat test