_:vb50950519 . _:vb50950519 "url:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2601718/pdf/nihms57213.pdf"^^ . _:vb50950519 "A primary immunnodeficiency disease that is caused by a lack of infection-fighting antibody producing B cells (immunoglobulins) or B cells that are not functioning properly."^^ . _:vb50950519 . _:vb50950519 . _:vb50950519 "url:http://www.nichd.nih.gov/publications/pubs/primary_immuno.cfm#WhatisPrimaryImmunodeficiency"^^ . _:vb50950519 . _:vb50950519 . _:vb50950519 .