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A Gause

Publications and source records attributed to A Gause.

77 records · Page 5Linked to original sources
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Prevalence of ANCA in mixed cryoglobulinemia and chronic hepatitis C virus infection.

OBJECTIVE: To determine the prevalence, target antigens and clinical associations of antineutrophil cytoplasmic antibodies (ANCA) in chronic hepatitis C without extrahepatic manifestations and in chronic hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC) in two European centers. METHODS: 50 sera from patients with chronic hepatitis C and 116 sera from HCV-associated MC were tested for cytoplasmic or perinuclear pattern (C-ANCA/P-ANCA) by indirect immunofluorescence test (IFT). ANCA target antigens were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Clinical characteristics of the patients were not different between the two centers. Cryoglobulinemic vasculitis (CV) was biopsy-proven in about 90% of the MC patients. Two patients with HCV-associated MC and 1 patient with chronic hepatitis C had a P-ANCA. A C-ANCA was detected in 1 patient with HCV-associated MC. Eight patients with a HCV-associated MC and 5 patients with chronic hepatitis C had an ANCA either directed against bactericidal/permeability increasing protein (BPI) or cathepsin G (CG). BPI- or CG-ANCA positivity was not associated with a more severe disease course. The C-ANCA titer followed disease activity in one C-ANCA positive HCV-associated MC patient. The subspecificity of the C-ANCA was not determinable in that patient. CONCLUSION: Two new target antigens of ANCA have been identified in HCV-associated MC and chronic hepatitis C in this study. BPI-ANCA and GC-ANCA were present in about 10% of patients with HCV-associated MC or chronic hepatitis C. ELISA proved to be more sensitive in the detection of ANCA than IFT. The present study on chronic HCV infection adds to various reports on the induction of CG- and BPI-ANCA in chronic infections.

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The influence of chrysotherapy on T-lymphocyte subpopulations in rheumatoid arthritis.

We studied the influence of chrysotherapy on lymphocytes, B-cells, T-cells, and T-lymphocyte subpopulations in 9 rheumatoid-factor-positive female patients with rheumatoid arthritis (RA). After chrysotherapy, the white blood cell count decreased within 1 month; the percentage of lymphocytes, T-cells, and B-cells did not change significantly, nor did the proportion of helper cells as determined by reactivity with monoclonal antibody OKT4. In contrast, the percentage of suppressor T-cells reactive with OKT8 was significantly decreased (p less than 0.05) after 6 months. As a consequence, the helper/suppressor ratio, which was significantly higher than in age- and sex-matched controls (p less than 0.02), showed an even more pronounced deviation from normal values than before therapy. The implications of these findings in regard to a possible immunological mechanism of action of gold and the significance of the disturbance of the "immunoregulatory balance" between helper and suppressor mechanisms for the pathogenesis of RA are discussed.

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T-lymphocyte subpopulations in rheumatoid arthritis. II. Definition by monoclonal antibodies.

Samples of peripheral blood of 27 patients with seropositive rheumatoid arthritis (RA) and 27 healthy age- and sex-matched controls were coded and studied for lymphocyte subpopulations. Monoclonal antibodies and indirect immunofluorescence were used to analyse subpopulations of purified T cells: OKT3 reacts selectively with all peripheral human T cells, OKT4 defines the helper/inducer subpopulation and OKT8 the suppressor/cytotoxic T cells. RA patients had a significantly lower relative lymphocyte count (p less than 0.001). whereas the percentage of all T cells was similar in patients and controls, RA patients had a significantly higher proportion of helper/inducer cells (62 +/- 1.3 vs. 56 +/- 1.0, p less than 0.005) and significantly decreased suppressors/cytotoxic cells (25 +/- 1.5 vs. 32 +/- 1.0; p less than 0.001). This resulted in an increased "immunoregulatory ratio" of helper to suppressor cells in RA patients (2.68 +/- 0.17) compared to their normal controls (1.83 +/- 0.10; p less than 0.001). The proportions of T cells expressing HLA-D-like antigens (defined by a monoclonal antibody to human Ia) was not different in patients and controls. These findings confirm conclusions derived from our previous study of T cell subsets defined by the expression of Fe-receptors (Tm and Tg), that in the peripheral blood of patients with RA, helper mechanisms predominate over suppressor mechanisms. This derangement of the immunoregulatory balance may have an important role in the pathogenesis of seropositive RA.

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PubMedDate not supplied

T-lymphocyte subpopulations in rheumatoid arthritis.

We studied 24 patients with rheumatoid arthritis and 24 age- and sex-matched controls for lymphocyte subpopulations in the peripheral blood. Patients with rheumatoid arthritis had a significantly lower relative lymphocyte count (p < 0.005) and a higher percentage of T lymphocytes bearing Fc-receptor for IgM (TM) (p < 0.05). The proportion of B lymphocytes, total T lymphocytes and T lymphocytes with Fc-receptors for IgG (TG) in patients with rheumatoid arthritis was not different from that in controls. In 1 of 5 cases tested incubation of T lymphocytes in autologous rheumatoid factor positive serum instead of FCS resulted in significant reduction of TM and increase in TG cells. These results are discussed in relation to possible immunological factors involved in the etiology of rheumatoid arthritis.

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