[IgG subclasses in patients with symptomatic IgA deficiency].
BACKGROUND
Patients with IgA deficiency may be asymptomatic or may present recurrent infections mainly respiratory. A possible explanation for this variety of symptoms may be the association with a deficiency of IgG subclasses.


METHODS
Twenty-five patients with a symptomatic IgA deficiency with a mean age of 18 +/- 12 years were studied. The quantification of the IgG subclasses was performed by ELISA test with antisubclass specific monoclonal murine antibodies. Serum from 100 healthy adults was collected to determine normal values of the IgG subclasses.


RESULTS
Twenty-five (48%) had a deficiency of associated IgG subclasses (6 IgG2 deficiency, 1 IgG3, 3 IgG4 and 2 combined deficiency). The patient with a deficiency of associated IgG subclasses had more recurrent respiratory infections (chi 2, p < 0.03) and pneumonias (chi 2, p < 0.04). This group also had a greater FEV1 alteration (Student-t test, p < 0.04).


CONCLUSIONS
Patients with symptomatic IgA deficiency frequently present IgG subclass deficiency and are more likely to have recurrent respiratory infections and greater changes in pulmonary function.
de Gracia
J
J
Servicio de Neumología, Hospital General Universitari Vall d'Hebron, Barcelona.
Miravitlles
M
M
Vendrell
M
M
Ròdrigo
M J
MJ
Codina
R
R
Morell
F
F
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D017098:IgA Deficiency / Q000097:blood* / Q000150:complications; D017099:IgG Deficiency / Q000097:blood* / Q000150:complications; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged
D007074:Immunoglobulin G
Estudio de las subclases de la IgG en pacientes con déficit de IgA sintomáticos.