Biomedical subjects

G Tappeiner

Publications and source records attributed to G Tappeiner.

At least 55 records · Page 3Linked to original sources

PubMed1979

[Circulating immune complexes and necrotizing vasculitis].

55 patients with necrotizing and with various forms of lymphocytic vasculitis were investigated for the presence of vascular deposits of immunoglobulins (Ig) and C3 by immunofluorescence testing of skin biopsies and with a 125I-Clq-binding assay for the presence of circulating immune complexes. Vascular deposits of Ig and C3 were found frequently both in patients with necrotizing and with lymphocytic vasculitis. In contrast, C1q binding activity was found almost exclusively in sera of patients with systemic necrotizing vasculitis. With one exception, all sera with C1q binding activity were from patients with vascular deposits of Ig and C3. The implications of these findings for our understanding of the development of system involvement in necrotizing vasculitis are discussed.

Antigen-Antibody Complex↗

PubMed1979

[Necrotizing vasculitis: its manifestation as urticaria].

A case of urticarial vasculitis, a distinct form of necrotizing vasculitis is described. This entity is characterized by a chronic, persistent urticaria with petechiae and the histological features of necrotizing vasculitis. Serum complement is depressed and multisystem involvement can often be found. There is evidence for immune complexes to play a role in the pathogenesis of this disease.

Female↗

PubMed1978

Clq binding activity in lupus erythematosus: correlation with the "lupus band test".

A 131I C1q binding assay was employed to estimate C1q binding activity (C1q BA), presumably due to the presence of circulating immune complexes, in lupus erythematosus sera. Thirteen of 16 sera from patients with systemic lupus erythematosus (SLE) had elevated C1q BA. Only 1 of 17 sera from patients with generalized discoid LE (GDLE) and none of 5 localized DLE patient's sera had elevated C1q BA. A correlation between a positive LE band test and the level of C1q BA was apparent. A positive LE band test tended to occur in patients with higher levels of C1q BA, whereas a negative LE band test tended to occur in patients with low levels of C1q BA.

Adolescent↗

PubMed1978

Binding of soluble immune complexes to Raji lymphocytes. Role of receptors for complement components, C1q and C3-C3b.

We have found that, although the binding of particulate antigen-antibody complement complexes such as EAC to lymphoblastoid Raji cells is mediated largely through receptors for C3b, the binding of complement-containing soluble complexes such as those prepared with aggregated human IgG (AHG) occurs also via receptors for C1q. Evidence supporting this conclusion included: (1) Binding of AHG to Raji cells takes place after incubation in EDTA serum; (2) Binding of AHG does not occur in C1q deficient EDTA serum but does take place after addition of C1q; (3) The extent of binding of AHG in EDTA serum is a function of the amount of C1q present; (4) Raji cells can bind up to 5-4 times 10(5) molecules of 125I C1q per cell which can be blocked by unlabelled C1q; (5) AHG pre-incubated with C can bind to a T-cell line MOLT, which lacks receptors for C3b but possesses receptors for C1q to the same extent as Raji cells; (6) Immunoassays for immune complexes in human sera yield similar results whether Raji cells, MOLT cells or C1q precipitation is used for assay; (7) EAC-Raji cell rosettes can be inhibited with inulin-treated, C1q deficient serum containing C3b or C3d whereas binding of AHG or immune complexes in patient samples to Raji or MOLT cells is not inhibited by this reagent. We conclude that receptors for C1q on certain B and T lymphocytes may play an important role in physiologic functions of lymphocytes depending on binding of soluble immune complexes to their surfaces.

Antigen-Antibody Complex↗

PubMed1977

[Hyperacute rejection of an HL-A identical renal allograft (author's transl)].

Hyperacute renal allograft rejection is described in a patient suffering from mesangio-proliferative glomerulonephritis. The transplanted kidney was HL-A identical and the direct cytotoxic cross-match between the recipient's serum and donor lymphocytes was negative. Intrarenal consumption of C 3, but not of C 1 q, C 4, total haemolytic complement, IgG or Igm was demonstrated. Immunofluorescence studies exhibited dense granular deposits of C 3, but not of IgG, IgM C 1q or C 4. These findings together with the observation of beta 1 C-beta 1A converting activity in the patient's serum, raised the possibility that the alternative pathway of complement activation induced by nephritic factor could have operated in this case. Further studies will be necessary to clarify the question whether hyperacute rejection of renal allografts is only antibody mediated or not.

Acute Disease↗

PubMed1977

C1q binding substances in pemphigus and bullous pemphigoid. Detection with a [131I] C1q binding assay.

A modification of the [125I]C1q binding assay was developed to allow the estimation of C1q binding activity (C1q BA) in pemphigus and bullous pemphigoid sera. The modifications include lower final concentration of PEG 6000 (1-5%) which permitted the use of sera that had been stored at -20 degrees C for extended periods of time; use of 131I instead of 125I and an [131I] C1q concentration of 5 microng/ml rather than 1 microng/ml. EDTA was used at a final concentration of 0-13 M to obviate the need for heat inactivation of sera. Sera from seventy-one patients with pemphigus and from 142 patients with bullous pemphigoid were tested for C1q BA. Of these 40% of the pemphigus and 20% of the bullous pemphigoid patients showed elevated C1q BA. A relationship between elevated C1q BA in serum and active disease was noted. Sequential samples from forty patients with pemphigus and thirty-seven patients with bullous pemphigoid demonstrated two different types of relationship between serum antibody titres to cutaneous antigens and C1a BA. In some patients serum antibody titres and C1q BA increased and decreased simultaneously; in others, increase of C1q BA followed increase of antibody titre and coincided with its decrease. The latter relationship supports the hypothesis that C1q BA may represent at least in part antigen-antibody complexes containing cutaneous antigens.

Antibodies↗

PubMed1976

The immunopathology of herpes gestationis. Immunofluorescence studies and characterization of "HG factor".

Nine skin biopsies from seven herpes gestationis patients were studied by immunofluorescence (IF) techniques. Basement membrane zone (BMZ) deposition of C3 and properdin was present in all nine skin specimens, while IgG deposition was apparent in only one. With in vitro C3 IF staining, positive BMZ staining (HG factor activity) was noted with all seven of our patients' serum samples tested. By standard indirect IF staining, however, only one of these serum samples contained BMZ antibodies of the IgG type. Two cord serum samples, tested by these same methods, yielded positive in vitro C3 staining (HG factor activity) but negative indirect IF staining (IgG). HG factor activity was found to be stable at 56 degrees C for 30 min and in two of three specimens at 56 degrees C for 1 h. Treatment of the complement source (normal human serum) used in the in vitro C3 staining assay with Mg2-EGTA or use of C2-deficient serum as the complement source inhibited HG factor activity. HG factor blocked the specific staining of the BMZ of normal human skin by labeled bullous pemphigoid antibodies. By sucrose density gradient ultracentrifugation and gel chromatography (Sephadex G-200), HG factor activity eluted with IgG-containing fractions. The highly purified IgG fraction of two herpes gestationis sera was also positive for HG factor activity. Our studies suggest that HG factor is an IgG antibody that may not be demonstrable by conventional IF methods, but which activates the classical complement pathway.

Basement Membrane↗

PubMed1975