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Biomedical subjects

A Wiik

Publications and source records attributed to A Wiik.

At least 73 records · Page 4Linked to original sources
PubMed1996

Multiple autoimmune manifestations in monoclonal gammopathy of undetermined significance and chronic lymphocytic leukemia.

In 18 cases of monoclonal gammopathy of undetermined significance, MGUS (monoclonal gammopathy of undetermined significance), admitted for diagnosed or suspected peripheral neuropathy, 11 patients showed other co-existing autoimmune manifestations. Two had POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-component, and skin symptoms), the others mainly endocrinopathy and polyclonal pseudolymphoma. There were 13 cases of sensorimotor neuropathy, two cases of neuritis, while neuropathy could not be confirmed in three cases. Compared with a retrospective review of autoimmunity in a randomly selected CLL (chronic lymphocytic leukemia) cohort of 115 patients, 13 out of 42 patients with clinical and/or laboratory features of autoimmunity showed co-expression of autoimmune signs, the dominating traits being Coombs positive AIHA (auto-immune hemolytic anemia), platelet autoantibodies, endocrinopathy mainly associated with the thyroid gland, serological and/or rheumatological symptoms, but only one case of sensorimotor neuropathy. Viewed from a current model of acquired autoimmunity it is perhaps not surprising that such autoimmunity is seen predominantly in patients with monoclonal gammopathy. Thus, a high concentration of cross-reacting polyreactive autoantibodies related to the M-component might be present in these patients. Furthermore, quantitative defects of the immunoglobulins including the hypogammaglobulinemia associated with M-components can presumably give rise to a defect of the anti-idiotypic network's regulation of natural autoantibodies and autoimmune manifestations in vivo. Such autoimmune manifestations, which are easily overlooked in CLL may call for additional treatment with immunosuppression and/or intravenous, polyclonal IgG.

Adult↗
PubMed1995

Clinical correlates and substrate specificities of antibodies exhibiting neutrophil nuclear reactivity--a methodological study.

In a serological laboratory with a routine service for determining autoantibodies to human neutrophils, antibodies giving a selective or preferential reaction with the nucleus or perinuclear area of neutrophils are not uncommon. The aim of this study was to look for clinical correlates with the presence of such neutrophil-reactive autoantibodies. The specificity of such antibodies for nuclear or cytoplasmic antigens was studied in 65 consecutive sera displaying nuclear/perinuclear reactivity at a titre of at least 80 using the indirect immunofluorescence technique (IIF) on ethanol-fixed leucocytes. The sera were also investigated by IIF on formalin-acetone fixed leucocytes and on HEp-2 cells. ELISA techniques were used to measure antibodies to azurophil granule constituents (ANCA), purified myeloperoxidase (MPO-ANCA), and lactoferrin (LF-ANCA). Furthermore a qualitative spot immunoassay was used for the detection of antibodies to alpha, beta, and gamma fractions, and the nuclear fraction of neutrophils, purified proteinase 3 (PR3), MPO, enolase, lysozyme, elastase, lactoferrin, and cathepsin G. The diagnoses linked to such GS-ANA/pANCA positivity were arthritides, vasculitides, inflammatory bowel disease and chronic hepatic conditions. MPO was the main antigen recognized in the vasculitis group, but apart from that, rather limited antigen reactivity was demonstrable by these techniques, lysozyme being the most frequently recognized autoantigen in patients with arthritides. Human lymphocytes served as a suitable control substrate when distinguishing between GS-ANA/pANCA and ANA, whereas HEp-2 cells usually could not be used if both classes of antibodies were present in a sample. Furthermore, formalin-acetone fixation is not recommended for routine use.

Antibody Specificity↗
PubMed1995

Characterization of biologically active antineutrophil cytoplasmic antibodies induced in mice. Pathogenetic role in experimental vasculitis.

OBJECTIVE: To investigate the pathogenetic role of antineutrophil cytoplasmic antibodies (ANCA) in Wegener's granulomatosis (WG). METHODS: BALB/c mice were immunized with human IgG ANCA from a patient with WG. Control mice were immunized with normal human IgG. Levels of mouse ANCA and other autoantibodies were determined. Mouse ANCA were tested for their ability to induce adhesion and respiratory burst of neutrophils. The mouse lungs and kidneys were examined for the development of vasculitis. RESULTS: Mice immunized with human ANCA developed anti-human ANCA and anti-anti-human ANCA (mouse ANCA), while the controls did not develop these antibodies. Mouse ANCA were capable of inducing adhesion of neutrophils to fibronectin and activating the respiratory burst in neutrophils. Moreover, the mice that were immunized with human ANCA developed perivascular mononuclear cell infiltrates in the lungs, suggesting vasculitis. CONCLUSION: The results suggest a pathogenic role of ANCA in WG, and may imply that activation of neutrophils is the initiating event in the development of vasculitis in WG.

Animals↗
PubMed1995

Integral membrane proteins associated with the nuclear lamina are novel autoimmune antigens of the nuclear envelope.

We have analyzed sera from 55 patients, most with rheumatic diseases, that all react with the nuclear envelope of human cells in immunofluorescence microscopy. The molecular targets of these autoantibodies were characterized by immunoblot analysis of fractions derived from rat liver nuclear envelopes. While numerous sera were found to react with previously characterized autoimmune antigens of the nuclear envelope including nuclear lamins and the pore complex glycoprotein gp210, a substantial number of the sera were found to recognize relatively minor integral membrane proteins of the nuclear envelope associated with the nuclear lamina (LAP 1A and LAP 2), which have not been previously identified as autoantigens. Autoantibodies to LAP 1A and LAP 2 are present in 9 and 29% of the patient sera, respectively. Only autoantibodies to lamins A/C were encountered more frequently (in 31% of the sera) than autoantibodies to LAP 2, suggesting that LAP 2 may be among one of the most prominent autoantigens of the nuclear envelope in rheumatic disease patients. Since recent studies have suggested that LAP 1A and LAP 2 may be involved in attaching lamins and chromosomes to the nuclear envelope, these findings could promoted understanding of nuclear envelope functions as well as autoimmunity.

Autoantibodies↗
PubMed1995

Screening for anti-neutrophil cytoplasmic antibodies (ANCA): is indirect immunofluorescence the method of choice?

Detection of ANCA has become an important tool for the diagnosis and monitoring of disease activity in Wegener's granulomatosis (WG). Unfortunately, a group of sera positive by the standard method for ANCA detection, indirect immunofluorescence (IIF), are negative when more specific tests with purified proteins are used. In order to examine this discrepancy we examined groups of sera selected for being (i) C-ANCA-positive by IIF; (ii) positive in proteinase 3 (PR3)-ANCA ELISA; and (iii) from 24 patients with WG. The following assays were used: IIF, PR3-ANCA ELISA and capture PR3-ANCA ELISA using MoAbs against PR3. Furthermore, since granule enzymes are released during coagulation, we also measured ANCA in complex with PR3. To test if granule enzyme release had any influence on ANCA detection, both serum and EDTA-plasma were collected from a patient with active WG. No difference, however, was found. In the IIF-positive group (n = 60) 68% of the sera were positive in PR3-ANCA ELISA, 86% in capture PR3-ANCA ELISA and 80% were positive for the PR3/IgG-ANCA complex. In the PR3-ANCA ELISA group (n = 105) 88% of the sera were positive by IIF, 98% in capture PR3-ANCA ELISA and 53% in the PR3/IgG-ANCA assay. To evaluate the tests clinically sera from 24 patients with WG were examined. In the remission group (n = 10) two patients were positive by IIF, four in the PR3-ANCA ELISA, and five in the capture PR3-ANCA ELISA. Fourteen had active disease, and in this group 11/14 were positive by IIF, 10/14 in PR3-ANCA ELISA and 12/14 by capture-ELISA. The correlation between IIF and capture PR3-ANCA ELISA titre (r = 0.72, P = 0.0095) was better than between PR3-ANCA ELISA and IIF (r = 0.56, P = 0.043). It is concluded that the capture PR3-ANCA ELISA is more sensitive than PR3-ANCA ELISA, and that the capture ELISA can be used for screening of PR3-ANCA.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1995

Immunization with anti-neutrophil cytoplasmic antibody (ANCA) induces the production of mouse ANCA and perivascular lymphocyte infiltration.

Wegener's granulomatosis (WG) is a granulomatous necrotizing vasculitis associated with the presence of ANCA, predominantly directed against proteinase 3 (PR3). The titres of ANCA correlate with disease activity and titre increases may precede disease exacerbations. Previously, we have shown that it is possible to induce autoimmune disease (systemic lupus erythematosus (SLE) and anti-phospholipid syndrome) in naive mice following active immunization with human autoantibodies, namely anti-DNA and anti-cardiolipin, respectively. The mice developed first anti-autoantibodies and, after about 4 months anti-anti-autoantibodies (Ab3), simulating auto-antibodies (Ab1) in their binding activities, and their presence was associated with the development of disease manifestations, characteristic of the human disease. So far, there is no good animal model for WG. In the current study we have immunized mice with human ANCA with the aim of inducing experimental WG. In two separate studies 30 mice were immunized in their footpads with autoantigen-purified IgG fraction (ANCA) from the sera of two patients with untreated WG, emulsified in Freund's complete adjuvant, followed 3 weeks later by ANCA injection in PBS. In the first experiment mice immunized with ANCA developed sterile microabscesses in the lungs after 8 months, and died after 8-15 months. In the second experiment, mice immunized with ANCA developed after 4 months mouse ANCA, with specificity both to PR3 and to myeloperoxidase, as well as anti-endothelial autoantibodies (AECA), as shown by radioimmunoprecipitation. Pathologically, the immunized mice developed proteinuria but not haematuria, and histological sections of the lungs demonstrated mononuclear perivascular infiltration, while diffuse granular deposition of immunoglobulins was noted in the kidneys. Our results point to a pathogenic role of ANCA in WG, and confirm the importance of the idiotypic network in the etiopathogenesis of autoimmune conditions.

Animals↗
PubMed1995

Anti-neutrophil cytoplasmic antibodies in chronic inflammatory bowel disease. Prevalence and diagnostic role.

BACKGROUND: Anti-neutrophil cytoplasmic antibodies (ANCA), originally found to be associated with vasculitis, have been reported to be present in chronic inflammatory bowel disease. Most often the ANCA staining pattern is of the perinuclear type (p-ANCA), although nuclear and cytoplasmic stainings are seen. Single studies have shown some of the antibodies to react with lactoferrin or cathepsin G; however, most studies have not been able to determine a main antigenic specificity. We studied the prevalence of ANCA in sera from 155 patients with ulcerative colitis, 128 patients with Crohn's disease, and 51 patients with coeliac disease. The presence of ANCA was correlated to disease activity, extent, and age of onset of the diseases. Furthermore, we tried to characterize the antigen specificity by enzyme-linked immunosorbent assay (ELISA), using elastase, lactoferrin, myeloperoxidase, proteinase 3, and cathepsin G as antigens. METHODS: The sera were screened for ANCA by indirect immunofluorescence. Anti-nuclear antibodies (ANA) were analysed on HEp2 cells, and ELISA for specific ANCA was performed using the antigens mentioned. RESULTS: Most of the sera with positive immunofluorescence had the p-ANCA type of pattern. Seventy-eight of 155 (50.3%) of the patients with ulcerative colitis were ANCA-positive, compared with 31 of 128 (24.2%) of patients with Crohn's disease (p < 0.001). However, in the subgroup with Crohn's colitis, 16 of 44 (36.4%) were ANCA-positive. Only 4 of 51 patients (7.7%) with coeliac disease showed positive immunofluorescence (p < 0.001 compared with ulcerative colitis). Less than 10% of the samples were positive in the specific ELISA assays; thus other than the most well known granule proteins can be the target for ANCA in ulcerative colitis. CONCLUSION: ANCA occur significantly more often in ulcerative colitis than in Crohn's disease. However, the prevalence of ANCA is rather high in Crohn's colitis. ANCA are thus of limited value in differentiating Crohn's colitis from ulcerative colitis. ANCA found in inflammatory bowel disease are different from those associated with vasculitis. The antigen(s) responsible remain to be determined.

Adult↗
PubMed1994

[Chronic fatigue syndrome--a defined unity?].

Chronic fatigue syndrome (CFS) is characterized by a sudden onset of an influenza-like illness followed by marked chronic fatigue and abnormal exercise-induced exhaustion. The precise pathogenesis of this disorder is unknown, but viral infection triggering immune imbalance has been suggested. The literature on CFS is reviewed. We find no consistent support for chronic viral infection or immunological dysfunction. The data in the published studies are rather conflicting, and further research in order to identify parameters that differentiate CFS from other disorders is necessary.

Diagnosis, Differential↗
PubMed1994

[Chronic fatigue syndrome--a controlled cross-sectional study].

Twenty-one patients fulfilling the Center for Disease Control criteria for chronic fatigue syndrome (CFS) were examined in a controlled study. Viral antibodies and tests evaluating the immune system were investigated in the patients and in a control group of 21 sex- and age-matched individuals. Production in vitro of the predominantly T-cell-derived cytokines interleukin-2 and interferon-gamma was significantly higher in patients with CFS compared the control group. Furthermore, the serum concentrations of IgA and IgE were significantly lower in patients with CFS; however, the values were within the normal reference range. All other variables were similar in the two groups. This study does not suggest a clearly disordered immune system or a chronic viral infection as a major pathogenetic factor in CFS. Longitudinal studies of immunological and virological parameters in CFS are warranted as are studies on patients that are severely handicapped.

Adolescent↗
PubMed1994

Measurements of proteinase 3 and its complexes with alpha 1-proteinase inhibitor and anti-neutrophil cytoplasm antibodies (ANCA) in plasma.

Wegener's granulomatosis (WG) is a systemic vasculitis which is diagnosed on clinicopathological findings. The diagnosis may be aided by the presence of anti-neutrophil cytoplasm antibodies (ANCA). In WG, ANCA are primarily directed to proteinase 3 (PR3), a serine protease of the azurophilic granules of the neutrophilic granulocyte. The main plasma inhibitor of PR3 is alpha 1-proteinase inhibitor (PI). To study if free PR3 or complexes between the enzyme and PI or PR3 and ANCA could be found in the plasma from patients with WG we have developed three ELISA systems for the detection of these complexes and free PR3. In all three assays monoclonal antibodies against PR3 were used as capture antibodies. After incubation with plasma, free PR3 was detected by affinity purified rabbit anti-PR3 followed by alkaline phosphatase-labelled swine anti-rabbit IgG. Serial dilutions of purified PR3 was used as standard. The detection limit was 3 ng/ml. PR3 complexed with PI was measured by rabbit anti-PI antibodies and alkaline phosphatase-labelled swine anti-rabbit IgG. Pre-formed in vitro complexes of PR3/PI in serial dilutions were used as standard. The detection limit of this assay was 1 ng/ml. PR3/IgG-ANCA complexes were detected by alkaline phosphatase labelled goat anti-human IgG. A positive plasma sample in serial dilutions was used as standard. Plasma samples from nine patients with WG, eight patients with fever of infectious origin without evidence of vasculitis and ten healthy donors were examined by these methods. Free PR3 could not be found in any of the plasma samples. PR3/PI complexes were detected in healthy donors at levels between 41-85 ng/ml. All WG patients, both active and inactive, had PR3/PI concentrations above this level, and so had all patients with fever. PR3/IgG-ANCA was found in three of the patients with WG, two being ANCA negative with inactive disease and one was ANCA positive with active disease. Thus, the developed methods can be useful for future studies of the clinical relevance of these complexes in patients with WG and possibly other vasculitides.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1994

Screening for autoantibodies to the nucleolar U3- and Th(7-2) ribonucleoproteins in patients' sera using antisense riboprobes.

In this study we report the detection of autoantibodies to the nucleolar U3- and Th(7-2) ribonucleoprotein (RNP) particles in sera from patients with connective tissue diseases. The method described employs radioactively labelled antisense U3- and Th RNA which are hybridized to immunoprecipitated U3- or Th RNA from a HeLa cell extract. Of the 66 sera that were screened with this method seven sera (11%) precipitated only Th RNP, 16 sera (24%) precipitated only U3 RNP and 4 sera (6%) precipitated both U3- and Th RNP. Both anti-U3 RNP and anti-Th RNP activity appeared to be mostly associated with scleroderma or scleroderma-associated diseases. Using this method we also showed that some of the Th RNP particles in a cell extract are associated with the La autoantigen. We conclude that for the identification of immunoprecipitated RNAs this method is very sensitive and provides unambiguous data.

Antibodies, Antinuclear↗
PubMed1994

The phylogeny of proteinase 3/myeloblastin, the autoantigen in Wegener's granulomatosis, and myeloperoxidase as shown by immunohistochemical studies on human leukemic cell lines.

Proteinase 3/myeloblastin (Pr3/MBN) is a serine protease found in primary granules of neutrophilic granulocytes and monocytes in man. This enzyme has been identified as the main autoantigen in Wegener's granulomatosis. Pr3/MBN was earlier identified in the promyelocytic cell line HL-60 and was assumed to be at least partly responsible for controlling proliferation and differentiation within the granulocytic-monocytic system. We have investigated 98 leukemic cell lines representing all lineages of the hemopoietic system. Pr3/MBN was found to appear in mature myeloblastic precursors and in CD34+ immature monoblastic cells and was restricted to the granulocytic and monocytic lineage. Myeloperoxidase (MPO) was found to be expressed earlier in development in the granulocytic lineage, but appeared later than Pr3/MBN in the monocytic lineage. The identification of cell lines which contained Pr3 only or MPO only may make them useful for demonstration of anti-neutrophil cytoplasmic antibodies in primary vasculitides.

Autoantigens↗
PubMed1994

Chronic fatigue syndrome--a controlled cross sectional study.

OBJECTIVE: To look for signs of immunodeficiencies and/or longstanding infections underlying chronic fatigue syndrome (CFS). METHODS: Twenty-one patients fulfilling the Centers for Disease Control criteria for CFS were compared to 21 age and sex matched controls. A number of viral antibodies as well as the following tests evaluating the immune system were studied: autoantibody profile, cell surface markers on isolated blood mononuclear cells, cytokine production, lymphocyte proliferative responses, natural killer cell activity and quantitation of immunoglobulin secreting cells. RESULTS: Production in vitro of the predominantly T cell derived cytokines interleukin 2 and interferon gamma was significantly higher in patients with CFS compared to the control group. Furthermore, the serum concentrations of IgA and IgE were lower in patients with CFS; however, this difference was caused by a larger number with values of IgA and IgE above the upper limit of the normal range among the controls than among the patients with CFS. All other variables were similar in the 2 groups. CONCLUSION: A pathogenically significant imbalance of the immune system in patients with CFS cannot be excluded. However, evidence of a causal link between abnormal immunity and CFS was not obtained.

Adolescent↗
PubMed1993

[Rheumatoid factor IgM analyses in Danish laboratories. An interlaboratory study].

The aim this study was to compare the correlation between the rheumatoid factor analyses in Danish laboratories. Concentrations of rheumafactor IgM were found in 10 different sera at 17 different laboratories. Thirteen laboratories used the ELISA technique and four the nephelometry technique. Correlation between the laboratories using the same technique was acceptable in the interval 10 to 200 IU/ml. Concentrations were higher when the nephelometry technique was used compared with the ELISA technique.

Denmark↗