<prompt> Acquire IgA deficiency may occur in ?Severe Congenital toxoplasmosisSevere Measles infectionSevere BrucellosisSevere Leptospirosis  <response>: Severe Congenital toxoplasmosis Block in B cell differentiation due to defective interaction between T and B cells. Naive B cells are not able to differentiate into IgA - producing cells. 