Purpose: To perform an immunologicallyinvestigation in children with respiratory problems of asthma and/or rhinitis (atopicor non atopic) in order to get a better understanding of the immune system imbalancein these patients.

Materials and Methods: 47 children ofboth sexes, aged between 6 and 15 years, who were attended for respiratorydiseases at the Division of Allergy and Immunology at Children's Hospital de la Santísima Trinidad fromCórdoba city were studied. According to information obtained on clinical history, physical examination and PRICK tests they were divided into two groups: Atopics (n= 25) and non-atopic (n = 22). After parents signed informed consent and children over 7years assent to participate inthe research work, samples of blood and saliva weretaken to determine immune globulinsconcentrations and specific activities as well as to study leukocytepopulations and lymphocytes subpopulations.

Results: As expected, levels of total serum IgE and therelative percentages of blood eosinophils were significantly higher in thegroup of atopic (A) children with regard to non-atopic (NA) children. The studyof specific serum IgE for DermatophagoidesPteronissimus only showed positive results in the A group, and positive correlationsbetween the levels of total and specific IgE, as well as PRICK and RAST values.Serum IgG and IgA levels showed no significantdifferences between both groups. Total salivary IgA concentrations weresignificantly higher in the group of NA children than in the group of Apatients. Surprisingly, when specificsalivary IgA for DermatophagoidesPteronissimus was studied, the opposite was observed: Atopic patients havenearly twice specific salivary IgA for this allergen than the NA children.

In the study of T cells subpopulations: CD3, CD4and CD8, no significant differences between groups were observed. Thesubpopulations of CD27^- Bcells and CD27 ⁺B cellswere similar in both groups (roughly 80% and 20%, respectively). In both groups,approximately 50% of CD27 ⁺Bcells expressed IgD and the remaining 50% were IgD^-.  However,atopic children had less than half B cells expressing high density of CD27 molecule(CD27 ⁺⁺⁺) with respectto the NA children (p = 0.044).

Conclusion: Among the immunological parameters investigated,we found significant differences between A and NA children in the concentrationsof total and specific IgE and salivary IgA to the allergen, and in a subpopulationof CD27 ⁺⁺⁺ B cells.These findings are debated in the discussion of the manuscript.