Stability of clinical chemistry analytes in blood collection devices.
Explore the source record for details and available documents.
Blood Specimen Collection↗
Biomedical subjects
F E Krapf
Publications and source records attributed to F E Krapf.
Antibodies against p24 of HIV-1 in patients with systemic lupus erythematosus?
The involvement of retroviruses in the etiopathogenesis of autoimmunity is discussed. Recently antibodies against p24 of HIV-1 were described in patients from Texas with SLE. Therefore we investigated the presence of these antibodies in our SLE collective (German caucasians and blacks from Michigan) employing ELISA and Western blot. No anti-p24 reactivity was observed in our SLE patients in Western blots, suggesting that there may be ethnological or regional differences between our patients those from Texas.
AIDS-Related Complex↗
The role of antineutrophil cytoplasm antibodies, anticardiolipin antibodies, von Willebrand factor antigen, and fibronectin for the diagnosis of systemic vasculitis.
Autoantibodies directed against cytoplasmic components of neutrophil granulocytes and monocytes (c-ANCA) are a disease specific marker for Wegner's granulomatosis (WG). Autoantibodies against cardiolipin (aCl) are specific for a subgroup of autoimmune disorders, which can also be associated with systemic vasculitis. Fibronectin (Fn) and von Willebrand factor antigen (vWfAg) are produced by blood vessel endothelial cells in response to injury. We tested sera of 61 patients with various types of systemic vasculitides, sera of 13 patients with retinal vasculitis, and sera of 199 patients with rheumatic diseases for c-ANCA, aCl, Fn, and vWfAg. c-ANCA was positive in 14/17 patients with WG, and 2/4 with polyarteritis nodosa (PAN). No serum from healthy donors or patients with other vasculitic or rheumatic diseases was positive for c-ANCA. Moreover, we found aCl, Fn, and vWfAg significantly elevated in almost all patients with vasculitic syndromes. Therefore, we consider c-ANCA a marker, specific for the diagnosis of WG or PAN, whereas aCl, Fn, and vWfAg are nonspecific but sensitive markers of vascular damage.
Adult↗
Circulating immune complexes in HIV-infected persons.
Circulating immune complexes are part of normal immune defense mechanisms and, therefore, present in various infectious--bacterial and viral--diseases. On the other hand, they are obviously involved in pathogenic mechanisms, e.g., autoimmune diseases or different forms of malignancies. Both autoimmune and infectious features are recorded in the acquired immunodeficiency syndrome. Thus, elevated levels of antigen-antibody complexes in HIV-infected persons had to be expected, and they were in fact demonstrated by several authors. In a cohort study, it was additionally shown that circulating immune complexes are of prognostic relevance. After an introduction concerning the physiological and pathophysiological role of circulating immune complexes in general, their involvement in the course of HIV infections is presented and discussed. In addition, there is a critical review of the most commonly applied assay systems for the detection and quantification of circulating immune complexes.
Antigen-Antibody Complex↗
Are retroviruses involved in the pathogenesis of SLE? Evidence demonstrated by molecular analysis of nucleic acids from SLE patients' plasma.
High molecular weight DNA of up to 20 kbp and, additionally, an RNase-insensitive RNA of more than 60 b were isolated from plasmapheresis fluids taken from patients with active systemic lupus erythematosus (SLE). Similar nucleic acids could not be demonstrated in the plasma samples from patients with Waldenstroem's disease, rheumatoid arthritis, myasthenia gravis, and other diseases including active systemic disorders. The purified nucleic acids were analyzed in several ways; they proved to be immunogenic by inducing polyclonal and monoclonal antibodies to natural DNA as well as to synthetic polynucleotides (e.g. polyguanylic acid) after injection into experimental animals (rabbits or mice respectively). Biochemical and molecular cloning analysis of the DNA revealed features like high levels of CpG-dinucleotides, usually not observed in common human DNA. A possible exogenous origin was substantiated by comparative sequence studies of cloned plasma DNA, which showed homologies to human retroviruses, e.g. PL1 (85%/60 b) and the sequences of the gag and pol genes of human immunodeficiency virus type I (85%/157 b). Experiments applying isolated plasma nucleic acids in transfection experiments showed the induction of morphological changes in an EBV-immortalized B-cell line drawn from a healthy human donor, such as vacuolization and syncitia formation. Northern blot analysis demonstrated, exclusively in the transfected cell line, the expression of mRNA homologous to the cloned plasma DNA. Using this clone as a probe, homologous sequences could be demonstrated by Northern blot analysis in EBV-immortalized cell lines from SLE patients only and, by means of DNA amplification, in peripheral blood lymphocytes from SLE and AIDS patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
[Churg-Strauss syndrome. Seldom seen or only seldom diagnosed?].
Explore the source record for details and available documents.
Diagnosis, Differential↗
[Immune complexes in allergies: evidence of IgE-containing immune complexes in Churg-Strauss vasculitis].
In five patients with vasculitis, hypereosinophilia and elevated serum-IgE levels, the diagnosis of Churg-Strauss syndrome was established. To identify a possible role of IgE in pathogenic mechanisms leading to vasculitis, a sequential precipitation of patients' sera was performed using various concentrations of polyethylene glycol 6000 (PEG). Using a radioimmunosorbent test, the precipitates obtained were tested for their IgE contents. Considerable amounts of IgE were found in the serum precipitates of all patients. In parallel studies, no IgE-containing precipitates were detected in sera from patients with different allergic diseases and high IgE serum levels. The demonstration of IgE-containing PEG precipitable material in all patients suffering from Churg-Strauss syndrome, together with the finding of an elevated C3d and C4 level and a decreased C3 level in one patient and an increased C3d level in a second patient, suggests that IgE-containing immune complexes play a pathogenic role in the Churg-Strauss syndrome.
Adult↗
Evaluation of plasma C3d and immune complex determinations in the assessment of disease activity of patients with rheumatoid arthritis, systemic lupus erythematosus, and spondylitis ancylopoetica.
Patients with rheumatoid arthritis, systemic lupus erythematosus, and spondylitis ancylopoetica were examined, along with healthy controls, for C3d plasma levels, circulating immune complexes, C3 serum levels, and CRP. Immune complexes were determined using a Clq binding assay, a 2.75% PEG precipitation technique, including the analysis of IgG and C3, and a new laser nephelometric latex test. C3d plasma levels were significantly (P less than 1%) elevated in all groups of patients as compared to controls. With regard to the demonstration of circulating immune complexes, the PEG precipitation method discriminated best between patients and the control population. It was not possible to differentiate between the different disease entities with neither C3d serum levels or immune complexes. Concerning the assessment of disease activity, none of the evaluated parameters alone appears to be of clinical relevance. The individual application of more than one immune complex assay in combination with the measurement of C3d serum levels must be recommended if disease activity is to be assessed.
Antigen-Antibody Complex↗
IgE-containing circulating immune complexes in Churg-Strauss vasculitis.
In five patients with vasculitis, hypereosinophilia, and elevated serum IgE levels a diagnosis of Churg-Strauss syndrome was established. To identify a possible role of IgE in pathogenic mechanisms leading to the vasculitis, we performed a sequential precipitation of the patients' sera with different concentrations of polyethylene glycol (PEG) 6000. Using a radio immunosorbent test, we tested the precipitates obtained for IgE. Considerable amounts of IgE were traced in the serum precipitates of all patients, especially after the second precipitation step (4.0% PEG). In contrast, no IgE-containing precipitates were detectable in sera from patients with different allergic diseases and high IgE serum levels. Together with an increase in C3d serum levels and the failure to demonstrate C1q-binding material in patients' sera, these data suggest the involvement of IgE-containing immune complexes in the pathogenesis of Churg-Strauss vasculitis, activating the complement via the alternate pathway.
Antigen-Antibody Complex↗