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Biomedical subjects

A Wiik

Publications and source records attributed to A Wiik.

At least 163 records · Page 9Linked to original sources
PubMed1977

Immune deposits in the dermo-epidermal junction in rheumatoid arthritis.

Skin biopsies from forty patients with rheumatoid arthritis were studied for presence of immune deposits in the dermo-epidermal junction zone. In about half of these unselected patients with classical and definite rheumatoid arthritis, IgM, complement components and fibrinogen antigenic material were found. A positive correlation is demonstrated between immune deposits and the presence of cryoglobulins in serum. The presence of complement components in the skin deposits was found to be clearly related to the clinical activity of the disease, as judged by Lansbury's index.

Adult↗
PubMed1976

The immunosuppressive effect of extracorporeal irradiation of the blood evaluated by blast transformation and membrane immune fluorescence tests.

The immunosuppressive effect of extracorporeal irradiation of the blood was investigated by in vitro blast transformation tests on circulating lymphocytes and on lymphocytes isolated from lymph nodes and by B-lymphocyte counts before, during, and after the treatment. Two consecutive patient series, from a controlled clinical trial of the effect of extracorporeal irradiation of the blood on the course of kidney transplantation, were studied. B-cell depeltion was found to be relatively larger than the total lymphocyte depletion. In vitro transformation tests on both circulating and lymph node lymphocytes showed large individual variations. There were no characteristic correlations between the results of these tests or with the number of circulating lymphocytes. Nor were there any characteristic changes in these tests during treatment. These results, together with previous experience, seem to contraindicate the value of irradiation of the blood as an immunosuppressive treatment.

Adult↗
PubMed1976

Antinuclear factors in sera from healthy blood donors.

Sera obtained from 466 healthy blood donors were investigated for presence of granulocyte-specific and organ-nonspecific antinuclear factors of the IgM, IgA and IgG classes, 110 sera also for complement-fixing and IgD class antinuclear factors. When undiluted sera were studied, most sera were found to contain antinuclear factors of one or more immunoglobulin classes (77 per cent). IgM, IgA and IgG antinuclear factors were found in 53, 44 and 14 per cent, respectively. At dilution 1:16, antinuclear factors of the IgM class were still detected in 16 per cent of the sera, while IgA and IgC antinuclear factors wre demonstrated in 6 and 2 per cent, respectively. Organ-nonspecific antinuclear factors were clearly more common than granulocyte-specific antinuclear factors. No serum contained complement-fixing or IgD class antinuclear factors. This study indicates the importance of using qualitative as well as quantitative techniques to distinguish between antinuclear factors in health and disease.

Adult↗
PubMed1976

Immunological studies in sarcoidosis: a comparison of disease activity and various immunological parameters.

We found it valuable to separate the heterogeneous types of sarcoidosis into more homogeneous groups on the basis of activity and duration of the disease. This view is supported in the present study by the finding of a marked depression of T-cell function in patients with chronic-active sarcoidosis. Patients with acute or chronic-inactive disease had only moderately depressed T-cell function as measured by tuberculin skin test and DNCB index. These results are in agreement with those of some previous investigations. The remainder of the abnormal findings, particularly low total number of circulation T lymphocytes, elevated serum IgG levels, and presence of autoantibodies, could not be correlated to disease activity, extent of the disease, or T-cell function. We have found no explanation for the presence of autoantibodies but suspect that they may be nonspecifically related to the disease process.

Adolescent↗
PubMed1975

Monoclonal immunoglobulinaemia associated with glomerulopathy.

Four patients with benign monoclonal immunoglobulinaemia and associated glomerulopathy are described. Immunohistochemical investigations of the immunoglobulin-containing cells in the bone marrow revealed an unexpectedly pronounced predominance of monoclonal over polyclonal cells as typically seen in macroglobulinaemia and multiple myeloma, but in contrast to the malignant plasma cell proliferations the percentage of immunoglobulin-containing cells only constitued 6-12% of the nucleated cells. The possible pathogenetic mechanisms relating monoclonal immunoglobulinaemia and glomerulopathy are unknown. The sera did not contain antibodies to glomerular basement membrane, cryoglobulins, antinuclear factors or antiglobulins. The immunohistochemical technique certainly offers a clear advantage over conventional bone marrow cytology in the study of patients with monoclonal immunoglobulinaemia.

Aged↗
PubMed1975

Antibacterial precipitins and autoantibodies in serum of patients with cystic fibrosis.

Sera from 84 patients with cystic fibrosis, 31 patients with other respiratory diseases and 21 control persons have been investigated for the occurrence of antibacterial precipitins and autoantibodies. Preciptins were studied by means of crossed immunoelectrophoresis, antinuclear factors by an indirect immunofluorescence technique and rheumatoid factors by the latex fixation slide test. A very heterogeneous antibacterial immune response was found in patients with cystic fibrosis, notably as regards Ps. aeruginosa. None of the other patients or controls had precipitins against this bacterium. The occurrence of precipitins against St. aureus and D. pneumoniae were more frequent in cystic fibrosis patients as compared with controls, but not as compared with other respiratory disease patients. No significant differences were found as regards precipitins against H. influenzae or the occurrence of rheumatoid factors. Antinuclear factors were more frequent in cystic fibrosis patients than in the other two groups investigated. A pronounced and heterogeneous humoral immune response against Ps. aeruginosa in cystic fibrosis patients chronically infected with mucoid strains of this bacterium was found to be correlated with poor prognosis and the reason for this is discussed.

Adolescent↗
PubMedDate not supplied

High serum levels of YKL-40 in patients with systemic sclerosis are associated with pulmonary involvement.

OBJECTIVES: YKL-40, a growth factor of connective tissue cells, is elevated in sera from patients with diseases characterized by inflammation, tissue remodelling, or fibrosis. The aim of the study was to determine serum YKL-40 levels in patients with systemic sclerosis (SSc) and to explore any possible clinical and prognostic associations. METHODS: YKL-40 was measured in sera from 88 patients with SSc (26 with diffuse and 62 with limited skin involvement) and in sera from 88 matched healthy controls. Immunohistochemical staining for YKL-40 antigen was performed in a biopsy from a patient with pulmonary SSc. RESULTS: Serum YKL-40 levels of the SSc patients were significantly higher than those of the controls (p<0.00001). Patients with pulmonary fibrosis by chest X-ray, obstructive ventilatory pattern, reduced diffusing capacity (DLco), and digital joint deformity due to skin retraction had significantly higher serum YKL-40 compared with patients without these findings. Patients with elevated serum YKL-40 had shorter survival times than patients with normal serum YKL-40 (p = 0.0005), although this was not independent of age and pulmonary function. YKL-40 protein expression was found in inflammatory cells in fibrosing pulmonary tissue from a patient with SSc. CONCLUSIONS: Serum YKL-40 is elevated in patients with SSc with pulmonary involvement.

Adipokines↗
PubMedDate not supplied

Multicenter validation of recombinant, natural and synthetic antigens used in a single multiparameter assay for the detection of specific anti-nuclear autoantibodies in connective tissue disorders.

OBJECTIVES: We investigated the feasibility of using a single multi-parameter test based mainly on recombinant autoantigens for the detection of anti-nuclear autoantibodies, and analyzed the agreement between this test format and conventional techniques. METHODS: The presence of autoantibodies was determined by a line immunoassay (LIA) in 755 sera derived from patients with different autoimmune connective tissue disorders. All sera were previously tested by standard assays that are routinely used at the 8 participating European centers. RESULTS: The overall sensitivity and specificity of autoantibody detection by LIA was similar or higher as compared to combined conventional techniques (CCT). In particular, the detection of anti-Ro52 in systemic lupus erythematosus (SLE) sera (P = 0.004) and anti-LA in both SLE (P < 0.0009) and in Sjögren's syndrome (P < 0.0009) sera was significantly more sensitive when using LIA compared to CCT. By contrast, CCT was never more sensitive than LIA for any of the markers. CONCLUSION: The LIA is a reliable alternative to a combination of conventional techniques for the detection of specific anti-nuclear autoantibodies. The multi-parameter test also reveals autoantibody reactivities that may not be detected when only a limited number of conventional techniques are applied.

Antibodies, Antinuclear↗
PubMedDate not supplied

Antipolymer antibodies in Danish fibromyalgia patients.

OBJECTIVE: To use a new immunologic assay to investigate antipolymer antibody (APA) levels in women with fibromyalgia (FM). METHODS: The study population consisted of 35 patients with FM and 129 controls. The controls were selected based on a prior history of breast surgery and the presence or absence of a prior hospital diagnosis of soft tissue rheumatism. Study subjects underwent blood sampling, including tests for antinuclear antibodies (ANA) and APA, a clinical examination, and an interview focusing on rheumatic complaints and self-reported disability. The severity of rheumatic symptoms/signs was scored from 1 (= none) to 5 (= severe) based on the clinical examination and the interview. RESULTS: FM patients in this study represented a broad spectrum of disease severity, with the majority having mild symptoms. FM patients had a higher symptom severity and myalgic scores than controls (p < 0.001 for both variables). Adjusting for symptom severity, a weak positive association between APA levels and FM was observed (p = 0.08). The APA level was inversely associated with age, i.e., decreasing APA levels were seen with increasing age (p = 0.008). CONCLUSION: FM patients tended to have slightly higher APA levels than controls when adjusted for symptom severity. APA levels declined with age, a finding that has not been reported previously. The APA test and its clinical relevance should be evaluated in future studies.

Adult↗
PubMedDate not supplied

Appropriateness in anti-nuclear antibody testing: from clinical request to strategic laboratory practice.

As a result of rapid changes in laboratory technology, clinical behaviour and patients' expectations, along with limited economic resources, there is a greater requirement for an appropriate use of autoantibody testing. We examine the various aspects and the most controversial points of the diagnostic procedure in systemic autoimmune rheumatic diseases, and make recommendations for the most efficient approach to autoantibody testing, based on selected publications and the relevant literature. Appropriateness is a complex task that can be achieved only by combining the efforts from the laboratory and the clinic, thereby using scientific knowledge, inter-disciplinary consultation and expert clinical investigation.

Antibodies, Antinuclear↗
PubMedDate not supplied

Clinical optimization and multicenter validation of antigen-specific cut-off values on the INNO-LIA ANA update for the detection of autoantibodies in connective tissue disorders.

OBJECTIVES: The INNO-LIA ANA Update is a qualitative multiparameter line immunoassay for detection of autoantibodies to several different antigens associated with connective tissue disorders. We sought to optimize and validate the cut-off values for its antigen-specific components: SmB, SmD, RNP-70k, RNP-A, RNP-C, SSA/Ro52, SSA/Ro60, SSB/La, Cenp-B, Topo-I, Jo-1, ribosomal P, and histones. Our aim was to achieve 98% specificity for each of the markers, with respect to differential disease controls, while maintaining sensitivity. METHODS: For optimization, the cut-off value of the different antigen lines was fixed to achieve this specificity using an in-house set of 955 patient samples. Specificity was validated at multiple sites using a different set of 330 samples obtained from 158 apparently healthy blood donors, 100 patients with a variety of infections, 20 each with Wegener's granulomatosis, inflammatory bowel disease, and primary antiphospholipid syndrome, and 12 with psoriatic arthritis. Sensitivity was evaluated, using this optimized cut-off control, in 147 patients with scleroderma, 93 with Sjögren's disease, 40 with systemic lupus erythematosus, 40 with rheumatoid arthritis, 39 with mixed connective tissue disease, and 19 with polymyositis. Sensitivity and specificity of the INNO-LIA ANA Update were determined using the clinical diagnosis as reference. RESULTS: The optimized cut-off values resulted in a specificity 98% or more for all LIA markers except one (histones 97.8%) in the validation set of 330 samples. The sensitivity for each marker tested in 378 samples from the target patient groups was comparable to that reported in the literature. CONCLUSION: The INNO-LIA ANA Update shows uniformly high specificities combined with sensitivities very similar to those of reference assays, in a single test format.

Antigens↗