Immunodeficiencies and fever syndromes

Question 1

Common variable immunodeficiency disorder (CVID)

Answer 1

B cell deficiency, characterised by reduced IgG, IgA, IgM levels in addition to poor response to protein basved (dTP) and polysacharide (pneumoccal) vaccines. Delayed diagnosis is common, with dx 20-40 years. Recurrent sinus or respiratory infections.
Immune dysregulation with predisposition to autoimmune conditions (RA), granulomatous diseases, and NHL. Bronchiectasis is a common cause of morbidity, while chronic diarrhoea is a commonly seen GI presentation.
CVID is not a single disease, rather a collection of hypogammaglobulinaemia syndromes.

Question 2

Hyperimmunoglobulin M syndromes

Answer 2

Failure to class switch from IgM (high avidity, low affinity). Defects in CD40 ligand. X-linked disease.