| 1. |
- Alper, CA, et al.
(författare)
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Immunoglobulin deficiencies and susceptibility to infection among homozygotes and heterozygotes for C2 deficiency
- 2003
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Ingår i: Journal of Clinical Immunology. - 0271-9142. ; 23:4, s. 297-305
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Tidskriftsartikel (refereegranskat)abstract
- About 25% of C2-deficient homozygotes have increased susceptibility to severe bacterial infections. C2-deficient homozygotes had significantly lower serum levels of IgG2, IgG4, IgD, and Factor B, significantly higher levels of IgA and IgG3 and levels of IgG1 and IgM similar to controls. Type I ( 28 bp deletion in C2 exon 6 on the [HLA-B18, S042, DR2] haplotype or its fragments) and type II ( non-type I) C2-deficient patients with increased susceptibility to bacterial infection had significantly lower mean levels of IgG4 ( p < 0.04) and IgA ( p < 0.01) than those without infections ( who had a higher than normal mean IgA level) but similar mean levels of other immunoglobulins and Factor B. Of 13 C2-deficient homozygotes with infections, 85% had IgG4 deficiency, compared with 64% of 25 without infections. IgD deficiency was equally extraordinarily common among infection-prone (50%) and noninfection-prone (70%) homozygous type I C2-deficient patients. IgD deficiency was also common (35%) among 31 type I C2-deficient heterozygotes ( with normal or type II haplotypes), but was not found in 5 type II C2-deficient heterozygotes or 1 homozygote. Thus, C2 deficiency itself is associated with many abnormalities in serum immunoglobulin levels, some of which, such as in IgG4 and IgA, may contribute to increased susceptibility to infection. In contrast, IgD deficiency appears not to contribute to increased infections and appears to be a dominant trait determined by a gene or genes on the extended major histocompatibility complex (MHC) haplotype [HLA-B18, S042, DR2] ( but probably not on type II C2-deficient haplotypes) similar to those previously identified on [HLA-B8, SC01, DR3] and [HLA-B18, F1C30, DR3].
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| 2. |
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| 3. |
- Christensson, Marta, et al.
(författare)
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Serum sFAS levels are elevated in ANCA-positive vasculitis compared with other autoimmune diseases
- 2002
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Ingår i: Journal of Clinical Immunology. - 0271-9142 .- 1573-2592. ; 22:4, s. 220-227
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Tidskriftsartikel (refereegranskat)abstract
- The role of the Fas/FasL system in ANCA-associated vasculitis is unclear. We therefore assessed levels of soluble Fas (sFas) in sera and Fas expression on mononuclear cells from patients with ANCA-positive vasculitis and compared the results with those found in other rheumatic diseases. Serum levels of sFas were determined by ELISA. The ANCA-positive vasculitis patients studied included 29 at onset, 17 in first remission while on therapy, and 12 in quiescence. For comparison, 10 patients with Sjogren’s syndrome (SS), 14 patients with systemic lupus erythematosus (SLE), 29 patients with rheumatoid arthritis (RA), 7 patients on dialysis (DP), and 26 healthy controls (HC) were studied. In addition, Fas expression in mononuclear cells was examined at the mRNA level using reverse transcriptase (RT)-PCR in 6 vasculitis patients at onset and in first remission. The expression of CD95 on the surface of leukocytes was determined by flow cytometry in 6 vasculitis patients at onset of the disease, in 6 patients in clinical remission, and in 6 HC. Expression of Fas and FasL in renal biopsy specimens was studied using immunohistochemistry. Patients with vasculitis had high sFas levels irrespective of disease phase. Both vasculitis patients and patients with RA and SLE had significantly increased sFas levels compared with healthy controls. All patient groups had sFas levels, which correlated with raised serum creatinine values. However, the sFas levels in vasculitis patients in first remission and in quiescence were increased despite a lower serum creatinine compared with onset. Some of the vasculitis patients showed an increased mRNA expression of Fas in mononuclear cells after treatment, suggesting that Fas production fluctuates with the intensity of the disease. The expression of CD95 on leukocytes was slightly decreased in vasculitis patients compared to healthy controls. No alterations of Fas and FasL expression were seen in renal biopsy specimens. These results show that ANCA-positive vasculitis patients have high sFas levels and that the levels remain elevated even in clinical remission. The findings indicate that perturbations in the Fas/Fas ligand system may play a role in the disease process in ANCA vasculitis.
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| 4. |
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| 5. |
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| 6. |
- Eneslätt, Kjell, et al.
(författare)
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The regulation of FasL expression : a distinguishing feature between monocytes and T lymphocytes/NK cells with possible implications for SLE
- 2001
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Ingår i: Journal of Clinical Immunology. - 0271-9142 .- 1573-2592. ; 21:3, s. 183-192
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Tidskriftsartikel (refereegranskat)abstract
- Monocytes and lymphocytes from patients with systemic lupus erythematosus (SLE) had a higher cell surface expression of Fast than the corresponding cells from healthy individuals. Inhibitors of metalloproteases upregulated the surface expression of Fast in peripheral blood lymphocytes (PBL), indicating that a metalloprotease is responsible for the cleavage of FasL. The level of sFasL in serum was slightly increased in the patient group compared to the controls. Therefore, the possible contribution of various mononuclear cell types to the release of Fast was analyzed. Isolated NK cells and T lymphocytes released Fast into the medium and the release was prevented by inhibitors of metalloproteases. In contrast, isolated monocytes did not release Fast. FasR expression was elevated in patients with inverted CD4/CD8 ratio, while Fast expression showed no relationship to CD4/CD8 ratio. The absence of Fast release by isolated cells and a high level of surface expression of Fast distinguish monocytes and T lymphocytes/NK cells.
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| 7. |
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| 8. |
- Hahn-Zoric, Mirjana, 1949, et al.
(författare)
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Antibody response to the Haemophilus influenzae type b-tetanus toxoid conjugate vaccine in healthy and infection-prone individuals with IgG3 subclass deficiency.
- 2004
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Ingår i: Journal of clinical immunology. - 0271-9142. ; 24:5, s. 561-70
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Tidskriftsartikel (refereegranskat)abstract
- Searching for a possible explanation for the phenotypic heterogeneity in IgG3 deficiency, we studied the antibody response to a polysaccharide and a protein antigen in IgG3-deficient (IgG3d) adults after vaccination with Haemophilus influenzae type b capsular polysaccharide (Hib CP) conjugated to tetanus toxoid. Distribution of isotypes, idiotypes, clonotypes, and Gm allotypes were compared. All the vaccinated individuals, irrespective of the level of IgG3 and proneness to infections, developed protective levels of anti-Hib CP. Significantly lower prevaccination levels of IgG2 (p < 0.05) and IgG4 anti-Hib CP (p < 0.04 and p < 0.03) were noted among the infection-prone compared to the healthy IgG3d individuals and/or controls. Seventy percent of the IgG3d patients and none of the controls had the low responding Gm(ga-n/ga-n) genotype, while the majority of the controls had the alternative Gm(bfn/bfn) genotype. The conjugate ACT-HIB vaccine efficiently overcomes the IgG3 subclass deficiency state and the genetic predisposition for lower responsiveness, providing protection against Hib and tetanus infections. The proneness to infection in some IgG3d individuals may relate to their low prevaccination antibody levels.
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