Résumé
PURPOSE: People who suffer from chronic or recurrent respiratory disease have immunoglobulin deficiency due to hypofunction of B cell. Among these immunoglobulin deficiency, it has been reported that only one or two subclass of IgG are deficient with normal quantity of IgG and IgA. Therefore it is necessary to measure IgG subclasses in chronic or recurrent respiratory infection for diagnosis. The purpose of this study is to measure IgG subclass in children with chronic respiratory disease and administration of RU 41.740 which was obtained from Klebsiella pneumonia, K2O strain(it has proven role in control of immunity) comparing the changes of immunoglobulin levels and IgG subclasses with the control group. So that better therapeutic approaches can be made for these diseases. Subjectsand METHODS: Thirty-six patients who visited to Konkuk university hospital due to chronic and recurrent coughing from January 1993 to June 1994, were selected for this research. Their age ranged from 2~13 year old and patients with evident history of allergy or tuberculosis were excluded. RU 41.740 with antibiotics were given to 31 subjects and 5 subjects were given placebo with antibiotics. For all subjects IgG, A, M, E, IgG1, G2, G3, G4 were measured. Immunoglobulins were remeasured from 15 subjects who received RU 41.740 and from 5 subjects who received placebo. Results : 1) Five subjects out of 36 were low or low-normal IgG group and all combined with IgG subclass deficiency, and all of low or low-normal IgG group had IgG3 deficiency. Eighteen subjects out of 31 normal IgG group accompanied IgG subclass deficiency and 12 subjects had IgG3 deficiency, which is most common IgG subclass deficiency. 2) Four subjects out of 36 were IgA deficiency group. Three subjects from 4 accompanied IgG subclass deficiency and had IgG4 subclass eficiency. 3) After the RU 41.740 administration, the levels of IgG and IgG subclasses increased significantly in study group. There were no significant change in IgG and IgG subclasses levels in placebo group CONCLUSIONS: In patients with chronic or recurrent respiratory disease, it is necessary to measure IgG subclass. These diseases tend to be chronic and recurrent and can be severely complicated causing bronchiectasis and incurable otitis media. Generally these diseases are not responsive to antibiotics. Therefore therapies should be directed to increasing immunological function for better results.