[Specific antibody deficiency: Primary immunodeficiency associated to respiratory allergy]

Specific antibody deficiency (SAD) with normal immunoglobulin and normal B cells is a primary immunodeficiency characterized by reduced ability to produce antibodies to specific antigens especially polysaccharides.

To describe the characteristics of patients diagnosed with SAD emphasizing the association between primary immunodeficiency and allergic diseases.

Descriptive study showing patients with SAD treated at a public hospital between August 2007 and July 2015. Other secondary or primary immunodeficiency was discarded. The diagnosis of SAD was based on recurrent infections and abnormal response to pneumococcal polysaccharide vaccine assessed by specific IgG to 10 pneumococcal serotypes.

Twelve patients were included, 4 males, mean age 6 years, recurrent pneumonia predominated (91.7%) as well as other respiratory and invasive infections. All patients with SAD had associated asthma, 11 had allergic rhinitis, and other allergies. Three patients did not respond to any of the 10 serotypes contained in pneumococcal polysaccharide vaccine, and those who responded were with low titers. Treatment with conjugate pneumococcal vaccine was favorable in 11/12 patients.

In children older than 2 years with recurrent respiratory infections or invasive S. pneumoniae infections with normal immunoglobulin we recommend to investigate SAD, especially if they have a concurrent allergic disease.