title: Soluble Fc epsilon R II levels in normal children and patients with immunodeficiency diseases.
abstract: CD23 is expressed on mature B cells and is identical to a low-affinity IgE Fc epsilon receptor type II (Fc epsilon R II). The C terminal portion of CD23 is released to the serum as soluble Fc epsilon R II (sFc epsilon R II), which may be involved in regulation of IgE synthesis. We studied sFc epsilon R II levels in normal children and in patients with immunodeficiencies, including common variable immunodeficiency (CVI), partial DiGeorge syndrome, and immunodeficiency associated with ectodermal dysplasia to examine the relationship of sFc epsilon R II levels to B cell numbers and other immunoparameters. Serum Fc epsilon R II levels are higher in younger children (younger than 3 years) and decline gradually with age. In 11 patients with CVI with normal numbers of B cells (greater than 6%), sFc epsilon R II levels were comparable to that of control subjects. Five patients with CVI with deficiencies of peripheral B cells had levels of sFc epsilon R II similar to levels of control subjects. In all but one patient with partial DiGeorge syndrome, sFc epsilon R II levels were not significantly elevated, despite the presence of elevated peripheral B cell numbers. Of six patients with ectodermal dysplasia, four demonstrated increased Fc epsilon R II levels, a finding not correlated with serum IgE levels or with peripheral eosinophil or B cell numbers.
authors.affiliation: Department of Pediatrics/St. Petersburg, University of South Florida/All Children's Hospital 33701.
authors.forename: H
authors.initials: H
authors.lastname: Jyonouchi
authors.forename: R M
authors.initials: RM
authors.lastname: Voss
authors.forename: S
authors.initials: S
authors.lastname: Krishna
authors.forename: K
authors.initials: K
authors.lastname: Urval
authors.forename: H
authors.initials: H
authors.lastname: Sjahli
authors.forename: P B
authors.initials: PB
authors.lastname: Welty
authors.forename: R A
authors.initials: RA
authors.lastname: Good
mesh_terms: D000293:Adolescent; D015703:Antigens, CD / Q000097:blood*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004062:DiGeorge Syndrome / Q000276:immunology; D004476:Ectodermal Dysplasia / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis*; D007153:Immunologic Deficiency Syndromes / Q000276:immunology*; D007223:Infant; D011961:Receptors, Fc / Q000097:blood*; D017455:Receptors, IgE; D012016:Reference Values; D012995:Solubility
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D011961:Receptors, Fc; D017455:Receptors, IgE; D007073:Immunoglobulin E