Search PubMed⌕ Search

Biomedical subjects

A Cats

Publications and source records attributed to A Cats.

At least 127 records · Page 7Linked to original sources
PubMed1986

Comparison of immune complexes and complement components in arterial and venous blood of patients with rheumatoid arthritis.

Immune complexes (IC) are frequently found in the venous blood and synovial fluid of patients with rheumatoid arthritis (RA). Although IC are claimed to have a pathogenetic role in RA, there is generally poor correlation between different IC tests and between individual tests and clinical features. We have therefore sought differences in the levels of IC detected by the Clq binding assay (ClqBA) and the indirect polymorphonuclear phagocytosis test (IPPT) in the arterial and venous blood of 16 patients with RA and 6 disease control subjects to determine which IC are pathogenetically important. Complement components, IgA, IgG, and rheumatoid factor were also measured. Eight of 10 patients with clinically active RA had higher ClqBA results in arterial blood while IgA IC in the IPPT and most complement components were higher in venous blood. No such differences were seen in patients with inactive RA or controls. These results suggest that IC other than those containing IgA are not formed in limb tissues including the synovium and may explain the variable results previously seen in patients with RA.

Adult↗
PubMed1986

Ectopic calcification in hypophosphatasia.

The radiological findings in a 24 year old female with hypophosphatasia included frayed joint surfaces, intra- and peri-articular, and paravertebral calcification. These changes were compared to the usual radiographic findings in hypophosphatasia and prompted a family study. Excessive spinal osteophytosis and/or chondrocalcinosis was a relatively frequent finding in the relatives and it is suggested that these changes might indicate the heterozygous state.

Adolescent↗
PubMed1985

Spondylitic disease without radiologic evidence of sacroiliitis in relatives of HLA-B27 positive ankylosing spondylitis patients.

We report 2 independently-conducted family studies of HLA-B27 positive probands with ankylosing spondylitis (AS), both of which support the view that the clinical spectrum of AS is broader than ordinarily assumed, and should include individuals who have symptomatic disease but who do not show radiologic evidence of abnormalities of the sacroiliac joints or the spine. In the Cleveland study of 100 relatives of 30 B27 positive AS probands, 9 relatives did not show radiologic abnormalities of the sacroiliac joints or the spine but had symptoms of chronic inflammatory back pain previously reported to be characteristic of AS. These 9 relatives were all subsequently found to possess B27, in contrast with only 27 of 60 asymptomatic relatives (P less than 0.01). In the Leiden study of 101 relatives of 20 randomly chosen B27 positive AS probands, 13 of 86 relatives without radiographic evidence of sacroiliitis reported "thoracic pain and stiffness," as defined in the Rome criteria for AS. Twelve of these 13 symptomatic relatives were B27 positive. In contrast, among the remaining 73 relatives, only 33 were B27 positive (P less than 0.01). The occurrence of these characteristic spondylitic symptoms in B27 positive, but not B27 negative, relatives of AS probands suggests that the spectrum of the clinical manifestations of AS may include individuals with symptomatic disease, but without radiographic evidence of abnormalities of the sacroiliac joints or the spine. The relatively large number of females we found in this group suggests that women are more likely to manifest this variety of disease than are men.

Adult↗
PubMed1985

Phagocytosis and intracellular killing by polymorphonuclear cells from patients with rheumatoid arthritis and Felty's syndrome.

The present in vitro study concerned the phagocytosis and intracellular killing by polymorphonuclear cells (PMN) of 5 patients with rheumatoid arthritis (RA) and 12 patients with Felty's syndrome (FS). PMN phagocytosis was assessed by microbiologic and morphologic methods, and intracellular killing was measured independently of continuous phagocytosis of viable bacteria (Staphylococcus aureus). PMN from patients with RA or FS ingested S aureus opsonized with immunoglobulins and complement as effectively as did PMN from healthy donors. However, the capacity of patient PMN to ingest S aureus opsonized with sera lacking complement activity, e.g., heat-inactivated donor serum and the sera of 2 patients with FS, was lower than that of healthy donor PMN. This decreased ingestion is associated with diminished expression of Fc receptors on the membrane of PMN from patients who have RA or FS. As with sera lacking complement activity, decreased capacity to ingest S aureus was observed after preloading donor PMN with immune aggregates, which also decreased the expression of Fc receptors. PMN from patients with RA or FS were found to be as active in killing S aureus as cells from healthy donors.

Adult↗
PubMed1985

The value of complement and immune complex determinations in monitoring disease activity in patients with systemic lupus erythematosus.

Serial serum samples from 33 patients with systemic lupus erythematosus were tested for CH50, C3, C4, and circulating immune complexes. Circulating immune complexes were determined by 5 different assays. Disease activity was determined by a scoring system we devised. On an interpatient analysis, overall disease activity correlated significantly with levels of CH50, C3, and a positive result on C1q binding assay. However, with the exception of depressed C3 levels, the sensitivity, specificity, and predictive values of all the serologic tests were low. An intrapatient analysis revealed a patient-specific activity parameter in 11 of the 33 patients. We conclude that these serologic tests are not reliable in assessing disease activity in patients with systemic lupus erythematosus, although a small subgroup of patients will exhibit a patient-specific activity parameter.

Adolescent↗
PubMed1985

Radiological and scintigraphic findings in patients with a clinical history of chronic inflammatory back pain.

The prevalence of radiological abnormalities of the sacroiliac joints, the manubriosternal joint, and the lumbar spine were assessed, and quantitative sacroiliac scintigraphy was performed in 151 patients with a history of chronic inflammatory back pain and in 31 controls with non-inflammatory back pain. Sacroiliitis was found in 124 patients (82%), manubriosternal lesions in 84 patients (56%), and lesions of the lumbar spine in 58 patients (38%). In 19 patients (13%), manubriosternal lesions provided the sole radiological abnormality and in five patients (3%) no radiological abnormality could be demonstrated at any of these sites. Quantitative sacroiliac scintigraphy showed increased values in 69 of 137 patients examined (50%), but also in 10 out of 12 control patients with disc degeneration (83%) and is, therefore, nonspecific for inflammatory lesions. Radiological examination of the manubriosternal joint is recommended in patients with inflammatory back pain without radiographic evidence of sacroiliitis.

Adolescent↗
PubMed1985

Rheumatoid factors in rheumatoid arthritis and vasculitis.

To study the occurrence of rheumatoid factors (RF) in relation to the activity of rheumatoid arthritis and the occurrence of vasculitis, RF of IgM, IgA, and IgG classes were measured in sera from 35 patients with definite or classic rheumatoid arthritis (RA) using ELISA. For 26 patients, the RF levels were studied longitudinally and compared with changes in the articular index. Although IgM RF was occasionally found in patients without RA, IgA and/or IgG RF were almost exclusively associated with RA. The titers of IgM, IgA, and IgG RF were significantly higher in sera from patients with clinically diagnosed rheumatoid vasculitis than in sera from patients without vasculitis. No significant correlation between changes in the articular index and changes in titer of any class-specific RF could be found for the group of RA patients as a whole. However, in individual patients, increases or decreases in IgM and IgG RF titer were significantly correlated with an increase or decrease in the articular index.

Adolescent↗
PubMed1985

Felty syndrome: autoimmune neutropenia or immune-complex-mediated disease?

Immunofluorescence on polymorphonuclear cells (PMN) of patients with Felty syndrome (FS) revealed increased amounts of IgG, IgA, and IgM bound to the PMN surface compared with PMN of patients with rheumatoid arthritis alone. A positive correlation was found between the score for surface-bound immunoglobulins on FS-PMN and the results of the Clq binding assay in FS sera. After preincubation with sera from 20 patients with FS, immunofluorescence on PMN from healthy controls (HC) showed that these cells had bound IgG, IgA, and IgM. However F(ab')2 fragments of IgG from FS sera did not bind to PMN, although the antigen-binding reactivity of the F(ab')2 fragments was maintained as shown by control experiments. Immunoglobulins eluted from FS-PMN failed to bind to HC-PMN, whereas the corresponding IgG of patients with autoimmune neutropenia was bound. Gel filtration of FS sera on Sepharose 4B showed that the binding of IgG in FS sera to PMN did not coincide with the 7S peak but occurred mainly in fractions containing larger material. No binding of IgA and IgM to HC-PMN was found after incubation with FS sera pretreated with polyethylene glycol (PEG) to precipitate immune complexes. These results indicate that in sera of patients with FS the PMN-binding reactivity of IgG, IgA, and IgM is due to the binding of immune complexes containing these immunoglobulins and not to presence of autoantibodies directed to antigens on the neutrophil surface.

Antigen-Antibody Complex↗
PubMed1985

Symptomatic osteoarthrosis of the knee: a follow-up study.

In a retrospective study at a single rheumatology centre of 72 patients with symptomatic arthrosis of the knee, more than 50% of the clinical phenomena improved within six months while patients were treated conservatively. This improvement appeared to be irrespective of age and duration of knee complaints except for a group of obese patients with symptoms for more than one year.

Age Factors↗
PubMed1985

Evaluation of diagnostic criteria for ankylosing spondylitis: a comparison of the Rome, New York and modified New York criteria in patients with a positive clinical history screening test for ankylosing spondylitis.

The modified New York criteria for the diagnosis of ankylosing spondylitis were evaluated and compared to the older criteria in 151 patients, referred to hospital because of low back pain and who had a positive clinical history screening test for ankylosing spondylitis and in 31 controls with non-inflammatory back pain. Radiological examination of the sacro-iliac joints showed sacro-iliitis in 124 (82%) from the 151 with inflammatory back pain. In 110 (72%) of those patients a diagnosis of definite ankylosing spondylitis according to the classical New York criteria could be made and they had a prevalence of HLA-B27 of 84%. Application of the modified New York scheme increased the number of patients meeting the criteria for definite ankylosing spondylitis to all 124 patients with sacro-iliitis, and 82% of this group carried HLA-B27. The classical New York criteria of 'limitation of the lumbar spine in three directions' and of 'limitation of chest expansion' appeared to reflect disease duration rather than help in the initial diagnosis.

Adolescent↗
PubMed1985

IgE deposition in normal skin of patients with rheumatoid arthritis in relation to clinical and laboratory findings.

Biopsy specimens from apparently normal skin of 28 patients with classical or definite rheumatoid arthritis (RA) were examined for the presence of IgE deposition by a direct immunofluorescence technique. IgE deposition was found in 12 patients (43%) and in none of the 10 controls. This deposition was mainly localised on mast cells, and in three patients perivascular IgE staining was also noted. The skin from nine of the 12 patients also showed deposition of IgM and complement C3 or C4 factor, or both. All 12 patients with skin IgE deposition had raised levels of IgM rheumatoid factor (RF) in the serum. Nine of these also had IgE RF. IgE-containing circulating immune complexes (IgE CIC), raised serum IgE levels, and extra-articular (EA) manifestations were present in respectively 10, nine, and eight skin IgE positive patients. It is suggested that IgE and IgE CIC may be involved in the pathogenesis of RA and its EA manifestations.

Adult↗
PubMed1985

Binding and activation of human precursor C1 by soluble aggregates of human and rabbit IgG.

The capacities of soluble human and rabbit IgG aggregates to bind and to activate human C1 were compared. Aggregates prepared by incubation of purified IgG at 63 degrees C were fractionated by gel filtration and hemolytic assays were used to measure the binding and activation of isolated human precursor C1. The C1 binding and activation capacities of both human and rabbit IgG aggregates were highly dependent on their size. Human IgG aggregates had a slightly higher binding avidity for human C1 than rabbit IgG aggregates of comparable size, but no clear differences were found between their capacities to activate C1. Experiments with nonaggregated IgG also indicated that although human IgG binds human C1 somewhat more avidly, human and rabbit IgG do not differ in their capacities to initiate fluid-phase activation of the human classical complement pathway.

Animals↗
PubMed1985

Reduction of the complement activation capacity of soluble IgG aggregates and immune complexes by IgM-rheumatoid factor.

The influence of IgM-rheumatoid factor (IgM-RF) on the activation of isolated C1 by soluble IgG aggregates (AIgG) and immune complexes was studied. IgM preparations obtained from the sera of four patients with seropositive rheumatoid arthritis markedly reduced the C1 activation capacity of AIgG, especially when large aggregates were tested. The results of parallel experiments with radiolabelled AIgG indicated that this inhibitory effect of IgM-RF was accompanied by a very large increase of the aggregate size. A comparable IgM preparation isolated from pooled normal human serum influenced neither the size nor the C1 activation capacity of AIgG. The inhibitory effect of IgM-RF on C1 activation was also demonstrated for soluble tetanus-anti-tetanus immune complexes. Thus, in spite of the established C activation ability of IgM-RF and the fact that, in general, larger IgG aggregates and immune complexes activate C1 more efficiently, cross-linking and size enlargement of soluble IgG complexes and aggregates by IgM-RF lead to a decrease of the C1 activation capacity. As a consequence, IgM-RF may reduce plasma complement activation by soluble IgG complexes in the circulation of patients with seropositive rheumatic diseases.

Antigen-Antibody Complex↗
PubMed1985

IgA containing immune complexes in rheumatoid vasculitis and in active rheumatoid disease.

Serum and synovial fluid (SF) from 68 patients with rheumatoid arthritis (RA) were studied for the presence of immune complexes (IC) and the results correlated with extraarticular features and/or disease activity. IC were measured by the 125I Clq binding assay (ClqBA) and with one detecting IgG, IgA, C3 or C4 in IC. Disease activity correlated significantly with IgG or IgA containing and Clq binding IC. The IgA containing IC were found only in 25% of the patients, including all but one case of rheumatoid vasculitis, but otherwise only in seropositive active RA. C3 and C4 IC did not correlated with disease activity, seropositivity or vasculitis. IC in serum did not correlate with SF levels, but C4 containing IC were more frequent in SF (60%) than in serum (30%). Thus serum IC did not reflect SF levels. Patients with vasculitis showed more IC in the sera than in SF.

Adolescent↗
PubMed1984

The risk of developing ankylosing spondylitis in HLA-B27 positive individuals. A comparison of relatives of spondylitis patients with the general population.

The present study was performed on 61 HLA-B27 positive first-degree relatives and 40 HLA-B27 negative relatives of 20 HLA-B27 positive probands with ankylosing spondylitis (AS). Of 24 HLA-B27 positive relatives 45 years or older, 21% had AS and 38% sacroiliitis. The HLA-B27 negative relatives did not have features of either disease. In the population study of 2,957 individuals 45 years or older, we found 5 cases of HLA-B27 positive sacroiliitis (according to the New York criteria) and 3 of these fulfilled the New York criteria for diagnosis of AS. In 2 of these 3 individuals, the diagnosis was made on clinical grounds. The phenotype frequency of HLA-B27 in this population is 7.8%, or about 230 HLA-B27 positive individuals in this population sample. Since AS was found in only 3 individuals, 1.3% of the HLA-B27 positive individuals in the population at large have AS; therefore, our data show that among individuals 45 years or older, 21% of HLA-B27 positive relatives of HLA-B27 positive AS patients have AS as compared with 1.3% of the HLA-B27 positive individuals in the population at large. Thus, the risk for AS is 16 times greater in the HLA-B27 positive relatives compared with HLA-B27 positive individuals in the population at large. The discriminatory value of the New York criterion of history of pain or the presence of pain at the dorsolumbar junction or in the lumbar spine was analyzed in the population and family studies and was found to be too nonspecific.

Adolescent↗
PubMed1984

Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria.

The New York and the Rome diagnostic criteria for ankylosing spondylitis (AS) and the clinical history screening test for AS were evaluated in relatives of AS patients and in population control subjects. The New York criterion of pain in the (dorso) lumbar spine lacks specificity, and the chest expansion criterion is too insensitive. The Rome criterion of low back pain for more than 3 months is very useful. Our study showed the clinical history screening test for AS to be moderately sensitive, but it might be better in clinical practice. As a modification of the New York criteria, substitution of the Rome pain criterion for the New York pain criterion is proposed.

Adolescent↗
PubMed1984

Psoriasis and arthritis. I. A population study.

In a population survey of 3659 persons aged 20 years or older, no association was found between psoriasis and rheumatoid arthritis. Inflammatory, degenerative and soft tissue rheumatic diseases occurred in 59% of the psoriatics and 46% of the controls. However, the mean number of rheumatological diagnoses in the psoriatics was 1.1 and in the controls 1.3. Features of psoriasis were found in 41 individuals (1.1%). Features of inflammatory arthritis (RA + past-polyarthritis) were established in 5% and 2.2% of the psoriatics and the controls respectively, but this difference is not significant. Because patients with psoriasis have complaints associated with the locomotor system more frequently than non-psoriatic people, it seems likely that the referral rate of the former to special clinics is higher.

Adult↗