Inmunodeficiencias primarias en el adulto. Estudio de los déficits de subclases de la IgG

Abstract

The deficit in IgG2 have been studied in children and proven relation with lung disease, but there are few studies with contradictory results, in relation to the adult population. In relation to the deficit selective IgG3 and IgG4 as a cause of pathology, there is no unanimity of criteria due to the low sensitivity and specify the techniques in relation to serum IgG subclasses quantification. Objective. - Reference values of the IgG subclasses in healthy adults. Establish the clinical characteristics of primary deficit of IgG subclasses and its indications of study in lung disease. Material and Methods . - To determine the normal values of the subclasses of IgG were studied 100 healthy individuals. The study group have been included by 356 individuals (257 adults and 99 between 15-7 years of age) who were grouped by order of entry for: deficit of IgA 25 patients; absence of IgE, 14 patients; bronchiectasis, 65 patients; recurrent pneumonia, 45 patients; COPD, 43 patients, chronic asthma, 53 patients, recurrent respiratory infections (infections of the respiratory tract that is accompanied by fever and a minimum of three episodes per year excluding pneumonia), 43 patients; simple asthma, 50 patients; and and pneumonia, 18 patients. Were excluded from the study patients with pathology associated with secondary immune deficiency and those who's a known cause (CF, CVI . . . ). Forced spirometry was performed in all patients. IgG subclasses quantification was performed using the ELISA technique. The reference values for each subclass of IgG were obtained from the mean ± 2 SD or as range of values if when normal or not distribution of values respectively (analysis Kolgomorov-Smirnov). The comparison of qualitative variables was performed using chi-square test and Fisher exact tes when necessary. The comparison of quantitative variables was performed by t- student or Wilcoxon test by unpaired data. Results and Conclusions. The reference values of IgG subclasses wre: IgG1, 261-1081 mg / dl; IgG2, 112-408 mg / dl; IgG3, 22-288 mg / dl; IgG4, 5-156 mg / dl. The prevalence of IgG subclasses deficit was significantly higher among people under age 16 (54%) compared to the adult population (32%) (P <0. 01). The IgG2 deficit was the most frequently observed. There were no significant differences in relation to sex. The clinical features that characterized the deficits of IgG subclasses and that should lead to suspicion of their presence are: a) IgA deficit in patients with symptomatic or with alterations in spirometry; serum absence of IgE in symptomatic patients c) bronchiectasis of unknown aetiology; recurrent pneumonia of unknown aetiology; d) COPD young patients in non-smokers or who require oral corticosteroids to control it; f) chronic asthma in patients with recurrent respiratory tract infections or which require oral corticosteroids; g ) Recurrent respiratory infections associated to bronchial hyperreactivity or sinusitis.

Date of Award	17 Apr 1991
Original language	Spanish
Supervisor	Antoni Bayés de Luna (Director) & Ferran Morell Brotad (Director)