title: Duodenal intraepithelial gamma/delta T cells and soluble CD8, neopterin, and beta 2-microglobulin in serum of IgA-deficient subjects with or without IgG subclass deficiency.
abstract: Expression of the gamma/delta T cell receptor (TCR) on CD3+ intraepithelial lymphocytes (IELs) was studied by two-colour immunofluorescence in duodenal tissue sections from healthy (n = 6) or infection-prone (n = 7) subjects with selective IgA deficiency (IgAD), and subjects (n = 4) with combined IgAD and IgG subclass deficiency. TCR gamma/delta+ IEL proportions in selective IgAD subjects (median 6.3%, range 1.0-41%) and in those with combined deficiency (median 4.5%, range 1.2-33%) were well within the range (0.3-38%) for histologically normal controls (n = 11), but the healthy IgAD subgroup tended to show raised TCR gamma/delta+ IEL proportions (median 13.6%) compared with the other two subgroups. Also the number of TCR gamma/delta+ IELs per intestinal length unit was relatively high (median 13.9/mm) in the healthy IgAD subjects, and significantly raised (P < 0.03) compared with controls (median 3.2/mm). Paired staining revealed that most TCR gamma/delta+ IELs in both selective IgAD (98%) and combined deficiency (99%) were CD8-, and a large fraction (median 84% and 63%, respectively) expressed the V delta 1/J delta 1-encoded epitope. The total number of CD3+ IELs (mostly CD8+) was similar to controls. IgAD subjects, and especially the healthy subgroup, had significantly increased serum concentrations of soluble CD8 (P < 0.0002), neopterin (P < 0.005), and beta 2-microglobulin (P < 0.007), which was similar to our previous observations in common variable immunodeficiency, and probably reflected stimulation of cell-mediated immunity. In addition, the increased TCR gamma/delta+ IELs might reflect a component of compensatory surface protection in the healthy IgAD subgroup.
authors.affiliation: Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), University of Oslo, National Hospital, Rikshospitalet, Norway.
authors.forename: D E
authors.initials: DE
authors.lastname: Nilssen
authors.forename: P
authors.initials: P
authors.lastname: Aukrust
authors.forename: S S
authors.initials: SS
authors.lastname: Frøland
authors.forename: F
authors.initials: F
authors.lastname: Müller
authors.forename: O
authors.initials: O
authors.lastname: Fausa
authors.forename: T S
authors.initials: TS
authors.lastname: Halstensen
authors.forename: P
authors.initials: P
authors.lastname: Brandtzaeg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001708:Biopterins / Q000031:analogs & derivatives* / Q000097:blood; D017252:CD3 Complex / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004386:Duodenum / Q000276:immunology*; D005260:Female; D006801:Humans; D017098:IgA Deficiency / Q000097:blood*; D017099:IgG Deficiency / Q000097:blood; D007074:Immunoglobulin G / Q000145:classification; D008297:Male; D008875:Middle Aged; D019798:Neopterin; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000032:analysis*
chemical_list: D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D007074:Immunoglobulin G; D016692:Receptors, Antigen, T-Cell, gamma-delta; D001613:beta 2-Microglobulin; D001708:Biopterins; D019798:Neopterin