pubmed-article:443046 | pubmed:abstractText | The IgA system in a patient with SCID and ADA deficiency showed heterogeneity. Serum IgA and stool secretory IgA (SIgA) levels were normal, but with altered kappa/lambda and A1/A2 subclass ratios; IgA in saliva and urine was deficient. Amounts of secretory component were normal. Jejunal and rectal biopsies showed prominent lymphonodular hyperplasia, but no cells containing IgA. A normal serum IgA level therefore does not always predict an intact secretory IgA system. | lld:pubmed |