Abstract
Introduction: Recurrent respiratory infections (RRI) are a common cause of morbidity during childhood.
Materials and methods: We report four cases of otherwise healthy preschool children who were referred to our paediatric allergy clinic for lower RRI with wheezing, crackles, cough and rhinitis, mostly during the autumn and winter months, since they started attending kindergarten. They were being treated with antibiotics, inhaled beta-2 agonists and corticosteroids for the exacerbations. They were on prophylactic therapy with fluticasone 200μg/day and montelukast 4mg/day, with no improvement. There was no history of atopy and the skin prick tests to common aeroallergens were negative. Chest-x-ray and sweat test were normal. All patients underwent an immunologic screening that included CBC, ESR, CRP, serum concentration of IgG, IgA, IgM, IgE, IgG1, IgG2, IgG3 and IgG4. The major Ig isotypes and the IgG subclasses were quantified by rate nephelometry. The laboratory investigation results were all within normal limits except of IgG3 which was in all patients below the 5th centile, based on published Greek normative data. IgG3 levels were: patient 1, aged 3.5: 10.5mg/dl (normal values 17-90), patient 2, aged 4.5: 20.7mg/dl (normal values 24-85), patient 3, aged 5: 13.6mg/dl (normal values 24-85), patient 4, aged 6: 14mg/dl (normal values 22-100).
Conclusion: IgG3 deficiency should not be ignored as a possible cause of RRI. Although it may be a transient phenomenon, it is prudent to follow these patients as some might evolve into common variable immunodeficiency. Moreover the use of increased doses of inhaled or systemic corticosteroids may delay the clearance of the virus from the respiratory tract.
- © 2011 ERS