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What is The commonest primary immunodeficiency is and explain in detail?
Isolated IgA deficiency Extremely low levels of serum & secretory IgA (may be IgG2 & IgG4 too) Defective differentiation of B cells to IgA producing plasma cells CF Mucosal immunity affected Recurrent sinopulmonary infections & diarrhoea When transfused with blood containing IgA may develop fatal anaphylactic reactions