Biomedical subjects

S Alsalameh

Publications and source records attributed to S Alsalameh.

22 records · Page 2Linked to original sources

PubMed1990

Cellular immune response toward human articular chondrocytes. T cell reactivities against chondrocyte and fibroblast membranes in destructive joint diseases.

Articular cartilage is one of the major targets in destructive joint diseases in humans. We studied cellular immune reactions against cartilage cell-surface membranes, because it has recently been suggested that these represent possible antigenic structures, based upon the observation of autoantibodies with this specificity in certain joint diseases. A striking T cell reactivity toward chondrocyte membranes was found both in blood and synovial tissue from patients with rheumatoid arthritis. This reactivity was strongly dependent on the presence of monocytes and had all the characteristics of an antigen-driven process. Clonal analysis demonstrated high precursor frequencies in peripheral blood T cells that were reactive against chondrocyte membranes. This response to chondrocyte membranes greatly exceeded the T cell stimulation induced by membranes from other sources such as fibroblasts or epithelial cells. In contrast to patients with rheumatoid arthritis, individuals with osteoarthritis showed a strong peripheral blood and synovial fluid T cell response not only to chondrocyte membranes, but also to fibroblast membrane material. However, there was no reactivity to epithelial cell membranes. Normal donors generally did not show significant responses to any membrane preparation. These data indicate that there is a strong T cell reactivity toward chondrocyte membranes in destructive joint disorders, and this may significantly contribute to the pathogenetic processes that occur in these diseases.

Adult↗

PubMed1990

Stimulation of rheumatoid synovial and blood T cells and lines by synovial fluid and interleukin-2: characterization of clones and recognition of a co-stimulatory effect.

Rheumatoid arthritis (RA) is characterized by the presence of interleukin-2 (Il-2) receptor-positive T cells in the peripheral blood and synovial compartments. Utilizing the limiting dilution technique, the precursor frequencies of Il-2 responsive T cells were determined in peripheral blood and synovial sites from RA patients and in the blood of normal donors. The frequencies of Il-2 responsive T cells were significantly higher in RA patients (range from 1/180 to 1/7432) compared to normal donors (range from 1/400 to 1/8163). T-cell clones raised by the addition of Il-2 alone were predominantly of the CD4-positive phenotype. Peripheral blood T cells, synovial T-cell clones and lines derived from RA patients were co-stimulated with Il-2 and synovial fluid or supernatants from cultured synovial lining cells. This co-stimulation induced a strikingly enhanced proliferative T-cell response while synovial fluid alone was without effect. This stimulatory activity was found in the high molecular weight range (approximately 150 kDa) and could not be attributed to the action of immunoglobulins or known cytokines such as Il-2 or interleukin-1 (Il-1), suggesting the activity of a material that modulates the Il-2-dependent growth of T cells. The co-stimulatory capacity of synovial fluid with Il-2 may be relevant to the activated state, especially of synovial T cells.

Adult↗

PubMedDate not supplied

[The role of cytokines and growth factors in rheumatoid joint destruction].

Cytokines and growth factors are important mediators of inflammation and play a major role in both the physiological regulation of bone and cartilage metabolism, and in the destruction of joint-related structures. These complex biological regulatory events have to be regarded as net effects which are dependent on the individual actions of the different cytokines and their corresponding inhibitors in the pericellular environment of the cells present in the inflamed tissues. These effects can be antagonized on various levels by natural or artificial inhibitory molecules. The determination and characterization of cytokines and their inhibitors in body fluids and tissues may contribute to a better understanding of the basic mechanisms of the pathogenesis of inflammatory joint diseases, and may help to develop better modalities of therapy. The objective of the present review is to outline important actions of selected cytokines and growth factors on cells and the surrounding matrix of bone and cartilage in rheumatoid arthritis. It will focus on interleukin-1 (IL-1), IL-1 inhibitors, Tumor-Necrosis-Factor-alpha (TNF-alpha), TNF inhibitors, Interleukin-6 (IL-6), colony-stimulating factors (CSF's), Interferon-gamma (IFN-gamma), growth factors, eicosanoids and prostaglandins, all of which are important in the effector phase of tissue destruction.

Arthritis, Rheumatoid↗

PubMedDate not supplied

[Comparison of rheumatoid test procedures--value and critical interpretation of sensitivity and specificity and their effect on pre-test and post-test probability].

In this prospective study, sera of 440 patients with rheumatic and degenerative joint diseases were tested for the presence of rheumatoid factor (RF). The Latex agglutination test (LFT), Waaler-Rose hemagglutination, laser nephelometry and IgM-Enzyme immunoassay (IgM-EIA) were used for detecting IgM-rheumatoid factors. In addition, rheumatoid factor of IgA isotype was measured by an IgA-Enzyme immunoassay. Sensitivity, specificity, pre-test- and post-test-probability were evaluated based on the data obtained to compare the test systems used. Under prospective patient selection, none of the test systems used reached a sensitivity of 100% concerning its cut off level. Despite this limitation, latex agglutination and IgM-EIA reached the highest sensitivity. Waaler-Rose test (90,8%) showed the best result for specificity. The IgA-EIA held the third position in sensitivity, specificity and efficiency. By comparing sensitivity with specificity, no test system can be recognized as the absolutely best one, since the receiver operating characteristic curves (ROC) overlapped. Practically rheumatoid factor measurement should initially use a highly sensitive assay, such as LFT and IgM-EIA to screen for RF. In the case of a positive result a more specific assay should be used, for example laser nephelometry, to confirm the result.

Adolescent↗