Pathophysiological functions of CD30+ CD4+ T cells in rheumatoid arthritis

The tumour necrosis factor/TNF receptor superfamily: therapeutic targets in autoimmune diseases

Autoimmune diseases are characterized by the body's ability to mount immune attacks on self. This results from recognition of self-proteins and leads to organ damage due to increased production of pathogenic inflammatory molecules and autoantibodies. Over the years, several new potential therapeutic targets have been identified in autoimmune diseases, notable among which are members of the tumour necrosis factor (TNF) superfamily. Here, we review the evidence that certain key members of this superfamily can augment/suppress autoimmune diseases.

The levels of sCD30 and of sCD40L in a group of patients with systemic lupus erythematodes and their diagnostic value

CD30/CD30L and CD40/CD40L are molecules from the tumor necrosis factor (TNF) superfamily. They have a major effect on communications between the B and T cells, which leads to control of maturation, proliferation, and apoptosis of those cells. The aim of this study was to compare the levels of a soluble form of CD30 (sCD30) and a soluble ligand CD40 (sCD40L) in patients with systemic lupus erythematosus (SLE) (n=65) and healthy controls (sCD30 n=20, sCD40L n=10) with other parameters of SLE activity. Patients were divided into subgroups according to presence or absence of lupus nephritis (LN; 33 with LN, 32 without LN). The serum levels of selected parameters were assessed also in the subgroups with low active disease characterized by European Lupus Activity Measure (ECLAM) at most 3(n=29) and active disease with ECLAM more than 3 (n=36). The serum levels of sCD30 were 66.0+/-40.2 UI/ml in the whole group. The mean serum levels were 60.0+/-45.2 UI/ml in the subgroups with LN, 67.1+/-38.9 UI/ml in the subgroup without LN, 80.2+/-51.9 UI/ml in the subgroup with active disease, 55.4+/-24.1 UI/ml in the subgroup with low active disease, and finally, 40.1+/-19.2 U/ml in the controls. Significant differences were found between the SLE patients and controls (p=0.0001) and between the active and nonactive groups (p=0.002). A correlation was found between levels of CD30 and ECLAM (r=0.25, p<or=0.05), SLEDAI (SLE Disease Activity Index) (r=0.25, p<or=0.05), C4 component of the complement system (r=0.24, p=0.02), and anti-C1q antibodies (r=0.42, p=0.0001). The levels of sCD40L were 7.4+/-6.7 ng/ml in whole SLE group, 7.0+/-8.1 ng/ml in the subgroup with LN, 8.0+/-4.9 ng/ml in the subgroup without LN, 7.1+/-5.0 ng/ml in the group of patients with active disease, 7.73+/-7.8 ng/ml in the subgroup with low activity, and 2.96+/-1.39.0 ng/ml in the controls. The difference in sCD40L serum levels between patients with SLE and controls was statistically significant (p=0.02). A correlation was found with the anti-C1q antibodies (r=0.21, p=0.05); no other correlations were found. These findings indicate some potential role of both serum parameters in measurement or SLE disease activity, although their usage in the diagnostic of disease requires further investigation.

Pregnancy in patients with rheumatic disease: anti-inflammatory cytokines increase in pregnancy and decrease post partum

OBJECTIVE

To investigate changes in the levels of circulating cytokines with a focus on the Th1/Th2 balance during and after pregnancy in patients with rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), and ankylosing spondylitis (AS).

METHODS

Plasma and serum samples of 34 pregnant patients, 19 with RA, 6 with JIA, and 9 with AS, and of 30 healthy pregnant women, 20 non-pregnant patients, and 10 non-pregnant healthy women were analysed for levels of interferon gamma (IFNgamma), interleukin (IL) 1beta, IL10, IL1 receptor antagonist (IL1Ra), soluble tumour necrosis factor receptor (sTNFR), and soluble CD30 (sCD30) by ELISA. Clinical assessment and blood sampling in pregnant women was done once in each trimester and 6, 12, and 24 weeks post partum. Disease activity in the patients was evaluated by validated clinical instruments and correlated with circulating levels of cytokines.

RESULTS

Low levels of IL10 were found sporadically, whereas IFNgamma and IL1beta were below detection level in the samples tested. Significantly higher concentrations of sTNFR and IL1Ra were measured in pregnant than in non-pregnant subjects. An increase of IL1Ra from the second to the third trimester correlated with improvement of disease activity in patients with RA and AS. Compared with non-pregnant patients and the other pregnant women, patients with RA showed markedly raised levels of sCD30 during pregnancy.

CONCLUSIONS

IFNgamma and IL10, markers of a Th1 and Th2 response, respectively, were either low or undetectable in the cohorts analysed. The increase of cytokine inhibitors IL1Ra and sTNFR was related to pregnancy and was independent of an underlying disease. These anti-inflammatory mediators seem to affect disease activity.

Resistance to IL-10 inhibition of interferon gamma production and expression of suppressor of cytokine signaling 1 in CD4+ T cells from patients with rheumatoid arthritis

IL-10 has been shown to block the antigen-specific T-cell cytokine response by inhibiting the CD28 signaling pathway. We found that peripheral blood CD4+ T cells from patients with active rheumatoid arthritis (RA) were able to produce greater amounts of interferon gamma after CD3 and CD28 costimulation in the presence of 1 ng/ml IL-10 than were normal control CD4+ T cells, although their surface expression of the type 1 IL-10 receptor was increased. The phosphorylation of signal transducer and activator of transcription 3 was sustained in both blood and synovial tissue CD4+ T cells of RA, but it was not augmented by the presence of 1 ng/ml IL-10. Sera from RA patients induced signal transducer and activator of transcription 3 phosphorylation in normal CD4+ T cells, which was mostly abolished by neutralizing anti-IL-6 antibody. Preincubation of normal CD4+ T cells with IL-6 reduced IL-10-mediated inhibition of interferon gamma production. Blood CD4+ T cells from RA patients contained higher levels of suppressor of cytokine signaling 1 but lower levels of suppressor of cytokine signaling 3 mRNA compared with control CD4+ T cells, as determined by real-time PCR. These results indicate that RA CD4+ T cells become resistant to the immunosuppressive effect of IL-10 before migration into synovial tissue, and this impaired IL-10 signaling may be associated with sustained signal transducer and activator of transcription 3 activation and suppressor of cytokine signaling 1 induction.