Immunoregulatory lymphokines in rheumatoid joints. II. Production by and responsiveness to interleukin-2 of eluted synovial tissue cells

Anaemia in rheumatoid arthritis: pathogenesis, diagnosis and treatment

The pathogenesis, diagnosis and treatment of the anaemia of chronic disorders (ACD) in rheumatoid arthritis (RA) were reviewed. Causes of anaemia other than ACD frequently present in RA. Decreased iron absorption was shown to be the result of active RA rather than a cause of ACD or iron deficiency. It has been hypothesized that bone marrow iron availability decreases due to decreased iron release by the mononuclear phagocyte system or that the anaemia in ACD is due to ineffective erythropoiesis; these remain controversial theories. Studies considering a decreased erythropoietin responsiveness have not produced consistent results. Erythroid colony growth is suppressed in vitro by interleukins and tumour necrosis factor but their role in vivo in ACD is unknown. The diagnosis of ACD is made by exclusion. Iron deficiency is detected by transferrin, ferritin, and cellular indices after adaptation of their normal values. Treatment of the anaemia consists merely of antirheumatic treatment. Iron administration is counterproductive since iron chelators or exogenous erythropoietin administration might increase erythropoiesis.

Mitogen-induced interleukin 2 and gamma interferon production by CD4+ and CD8+ cells of patients with inflammatory arthritides. A comparison between cells from synovial fluid and peripheral blood

The purpose of this study was to investigate interleukin 2 (IL-2) and gamma interferon (IFN-gamma) production by purified CD4+ and CD8+ cells isolated from peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and other inflammatory arthritides (non-RA). CD4+ and CD8+ cells were selected positively by immunomagnetic separation. Supernatants of unstimulated CD4+ and CD8+ cells from both compartments did not contain any detectable IL-2 or IFN-gamma, while supernatants of CD4+ and CD8+ cells stimulated with phytohaemagglutinin and irradiated Raji cells mostly contained both cytokines. In vitro stimulated SF CD4+ cells gave supernatants with significantly less IL-2 than supernatants from PB CD4+ cells, while in vitro stimulated SF CD4+-cell supernatants contained significantly more IFN-gamma. SF CD4+-cell supernatants contained significantly more IL-2 than the parallel CD8+ supernatants, while there was no significant difference with regard to IFN-gamma content. The pattern of differences between SF- and PB-derived T cells was the same for the two groups of patients, but the SF CD4+ cells from RA patients produced significantly less IL-2 than the corresponding cells from the non-RA group. The difference between SF and PB T cells with regard to lymphokine production is probably related to various degrees of in vivo pre-activation. The results do not indicate a major T-cell deficiency in relation to lymphokine production in RA.

A functional study of purified CD4+ and CD8+ cells isolated from synovial fluid of patients with rheumatoid arthritis and other arthritides

The purpose of this investigation was to study purified synovial fluid (SF) CD4+ and CD8+ cells from patients with rheumatoid arthritis (RA) and other inflammatory joint diseases (non-RA) with respect to the proliferative response to mitogens and recombinant interleukin 2 (rIL-2). Highly purified cell subsets were isolated by an immunomagnetic technique, and spontaneous proliferation as well as proliferative reSponses to rIL-2 and a combination of phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) (to substitute for accessory cells) were measured. Some patients had SF CD4+ and/or CD8+ cells with moderately increased spontaneous proliferation, but only the CD4+ cells of the two patient groups differed significantly from the peripheral blood (PB) T-cell subsets of healthy individuals who served as controls. The response to rIL-2 was variable but generally low, although about 50% of the CD4+ and 20% of the SF CD8+ cells of both patient groups expressed the Tac antigen. The response to PHA/PMA was significantly lower for RA SF CD4+ cells than for non-RA SF CD4+ cells, which again was lower than for normal PB CD4+ cells. SF CD8+ response to PMA/PHA by both groups of patients was somewhat decreased, but not significantly lower than in the controls. Thus, the CD4+ cells seemed functionally more deviant than the CD8+ cells in both patient groups, but the abnormality was most pronounced in the RA group. The results demonstrate that the previously reported diminished response to mitogens by SF mononuclear cells is present even when SF CD4+ cells are cultured alone. This indicates that these T cells have a reduced response, probably because of prior activation.

Expression of activation markers on CD4+ and CD8+ cells from synovial fluid, synovial tissue, and peripheral blood of patients with inflammatory arthritides

We studied the expression of the Tac antigen, the transferrin receptor (Tfr-R), HLA class II antigens (DR, DQ, DP), CD30, and Act 1 on purified CD4+ and CD8+ cells isolated from synovial fluid (SF), synovial tissue (ST), and peripheral blood (PB) of patients with rheumatoid arthritis (RA) and with non-RA inflammatory arthritides (not ST). Subfractionated T cells of PB from healthy individuals served as controls. SF CD4+ cells from RA and non-RA arthritides expressed the Tac antigen much more frequently than corresponding CD8+ cells (54 and 58% versus 16 and 17%). In contrast, SF CD8+ cells of both patient groups expressed the HLA class II antigens rather more frequently than the corresponding CD4+ cells (88 and 68% versus 72 and 40%). Tfr-R expression was low on CD4+ and CD8+ SF T cells from both patient groups. SF T cells did not express CD30, and their expression of Act 1 did not differ from that of normal PB T cells. The RA ST findings were similar to those of RA SF. The overall expression of activation markers on PB T cells of patients was slightly higher than on those of normal controls, and the RA group was slightly higher than the non-RA group. The results show that intra-articular T cells in arthritis are activated and that CD4+ and CD8+ subsets differ in their expression of Tac antigen and HLA class II antigens. There were also similar patterns of activation markers on both CD4+ and CD8+ SF cells from RA and non-RA arthritis patients, suggesting that several types of arthritis display a similar immunopathogenesis in the joints.

B-cell growth-promoting activity in supernatants from CD4+ cells from synovial fluid and peripheral blood of patients with rheumatoid arthritis and other inflammatory arthritides

The purpose of this study was to compare CD4+ cells from peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis with regard to mitogen-induced production of B-cell growth-promoting activity. CD4+ cells were isolated by a direct immunomagnetic technique and supernatants from both unstimulated and mitogen-stimulated CD4+ cells were studied. B-cell growth-promoting activity was assayed using highly purified B cells obtained from peripheral blood of healthy individuals. The indicator B cells were isolated by an indirect immunomagnetic technique and solid-phase anti-mu was used for activation of the B cells. Supernatants of unstimulated CD4+ cells from SF and PB did not contain B-cell growth-promoting activity, while usually high levels of B-cell growth-promoting activity were detected in the supernatants from mitogen-stimulated cultures. There was no significant difference in the B-cell growth-promoting activity level between supernatants from SF CD4+ and patient PB CD4+ cells, nor was there any significant difference between SF CD4+ and control PB CD4+ supernatants. The results indicate that the CD4+ cells in the SF have a normal potential for producing B-cell growth-promoting activity.

Immunoregulatory lymphokines in rheumatoid joints. III. B cell growth promoting activity of cells eluted from rheumatoid synovial tissue

Synovial fluid (SF) from rheumatoid arthritis patients (RA) and culture-supernatants of synovial tissue (ST) cells from RA patients and juvenile rheumatoid arthritis (JRA) patients were examined for their ability to promote B cell growth. SF was not suitable for studying B cell growth promotion because with the anti-mu driven assay system employed, all 15 samples strongly inhibited B cell proliferation. Supernatants of in vitro unstimulated ST cells from RA and JRA patients affected B cell growth in different ways, ranging from strong inhibition to moderate stimulation. Supernatants of unstimulated peripheral blood mononuclear cells (MNC) from healthy donors did not influence B cell proliferation. After phytohaemagglutinin (PHA) stimulation of the ST cells and normal MNC, culture supernatants of RA ST cells and normal MNC all stimulated B-cell growth, while culture supernatants of PHA-stimulated JRA ST cells displayed a variable picture. The differences between PHA-supernatants from RA, JRA and normal MNC were not statistically significant. These results indicate that the inflamed synovia of JRA and RA patients contain cells that can produce soluble factors with B cell growth promoting activity. Some of the data in the study suggest that these factors are produced in vivo and thus might be responsible for the observed B-cell activation in joints of these patients.