title: Transient IgG subclass deficiencies in newly diagnosed diabetic children.
abstract: In 27 children (15 males and 12 females) with insulin-dependent diabetes mellitus (IDDM), aged 1.2-13.5 years (mean 9.9 +/- 3.6 years) we investigated immunoglobulins (IgG, IgA, IgM), IgG subclass levels and islet-cell antibodies (ICA) at diagnosis and at 6 and 12 months after disease onset. At diagnosis, IgG levels were lower than -2SD in 7 patients (26%), IgA in 1 (3.7%), IgM in 1 (3.7%). IgG subclass levels were below the 3rd percentile in 13 patients (48.1%); in particular IgG1 in 7 (26%), IgG2 in 3 (11.1%), IgG3 in 2 and IgG4 undetectable in 1 case. In 3 out of the 13 patients combined IgG1-IgG3, IgG1-IgG2 and IgG1-IgG4-IgA deficiencies were observed. ICA were greater than 20 Juvenile Diabetes Foundation units in 17/27 patients. The HLA-DR2 frequency was higher in patients with IgG subclass deficiency than in patients with normal IgG subclass levels. During follow up, IgG levels normalized in 6 patients while IgA and IgM did not change. IgG1 normalized in 5 out of the 7 patients, IgG2 in all patients while IgG3 and IgG4 did not change. One year later ICA were still present in 8/27 patients. The hypogammaglobulinaemia and IgG subclass deficiencies observed in our patients could have either a genetic or an acquired basis.
authors.affiliation: Department of Paediatrics, University of Pavia, IRCCS Policlinico S. Matteo, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Cortona
authors.forename: M A
authors.initials: MA
authors.lastname: Avanzini
authors.forename: M
authors.initials: M
authors.lastname: Martinetti
authors.forename: R
authors.initials: R
authors.lastname: Lorini
mesh_terms: D000293:Adolescent; D000906:Antibodies / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000235:genetics / Q000276:immunology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006684:HLA-DR Antigens / Q000032:analysis / Q000235:genetics; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis; D007223:Infant; D007328:Insulin / Q000276:immunology; D007515:Islets of Langerhans / Q000276:immunology; D008297:Male; D013997:Time Factors
chemical_list: D000906:Antibodies; D006442:Glycated Hemoglobin; D006684:HLA-DR Antigens; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007328:Insulin