How is XLA differentiated from CVID in diagnosis?

XLA: male, B cells <2% of lymphocytes (typically <1%), onset in infancy, BTK mutation or absent BTK protein by flow cytometry. CVID: both sexes, B cells present but dysfunctional, onset typically 20–40 years, polyclonal IgG reduction. Newborn screening for B-cell TREC is now identifying XLA earlier.

What infections are seen in XLA?

Recurrent bacterial infections (Streptococcus pneumoniae, Haemophilus, Mycoplasma) in ears, sinuses, lungs. Enteroviral encephalitis is a serious complication. Patients tolerate intracellular pathogens and fungi normally due to intact T-cell immunity. IVIG prophylaxis dramatically reduces bacterial infections.

X-linked Agammaglobulinemia BTK Scoring

Apply diagnostic criteria for X-linked agammaglobulinemia: absent/very low B cells, severe panhypogammaglobulinemia, onset before age 5, mutations in BTK gene, or absent BTK protein by flow cytometry.

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X-linked Agammaglobulinemia BTK Scoring

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Frequently Asked Questions

How is XLA differentiated from CVID in diagnosis?

What infections are seen in XLA?