A patient suffering from recurrent mucosal infections and celiac disease. Turns out he is affected with a primary immunodeficiency. He is most probably affected with...?

Correct Answer: B

Rationale: IgA deficiency is a common primary immunodeficiency associated with recurrent mucosal infections and linked to autoimmune conditions like celiac disease.

Correct Answer: C

Rationale: C1q deficiency is strongly associated with a lupus-like syndrome due to impaired clearance of immune complexes, leading to autoimmunity. C3 deficiency causes severe bacterial infections, C5-9 deficiencies lead to neisserial infections, and C1 inhibitor deficiency causes angioedema, not lupus-like features.

Correct Answer: B

Rationale: SCID is the most severe congenital immunodeficiency, with absent T and B cell function, leading to early, life-threatening infections.

Correct Answer: B

Rationale: Selective IgA deficiency is the most common primary immunodeficiency, often asymptomatic but can lead to recurrent infections or allergies.

Correct Answer: A

Rationale: Leukocyte adhesion deficiency (LAD) causes leukocytosis, not neutropenia, due to impaired neutrophil migration, unlike the other conditions.