Expression of interleukin-21 receptor in epidermis from patients with systemic sclerosis.

OBJECTIVE: To examine the expression and regulation of interleukin-21 (IL-21) and IL-21 receptor (IL-21R) in patients with systemic sclerosis (SSc; scleroderma). METHODS: Skin biopsy specimens were obtained from 23 patients with SSc and 15 healthy controls. IL-21/IL-21R messenger RNA (mRNA) was quantified using real-time polymerase chain reaction (PCR). The expression pattern of IL-21/IL-21R was analyzed by in situ hybridization and Western blotting. Stimulation experiments were performed with cultured dermal fibroblasts from patients with SSc and healthy controls as well as with keratinocytes, using IL-1beta, platelet-derived growth factor BB, monocyte chemoattractant protein 1, transforming growth factor beta, and IL-21. The SCID-hu skin mouse model was used for in vivo experiments. RESULTS: IL-21R mRNA was detected in all biopsy specimens from patients with SSc and controls, with a 4.7-fold increase observed in SSc samples. In situ hybridization and immunohistochemical analysis showed an up-regulation of IL-21R in samples of epidermis from SSc patients, whereas no signal was detected in skin specimens from healthy controls. These results were confirmed in vitro, in that cultured keratinocytes expressed significant levels of IL-21R, whereas no signal was observed in fibroblasts. Interestingly, mRNA for IL-21 could not be detected by real-time PCR and in situ hybridization. Various concentrations of key cytokines in the pathogenesis of SSc did not stimulate the expression of IL-21R mRNA in cultured keratinocytes and dermal fibroblasts. In the SCID mouse transplantation model, the overexpression of IL-21R mRNA in SSc keratinocytes remained unchanged after transplantation. CONCLUSION: The up-regulation of IL-21R in keratinocytes indicates that, similar to fibroblasts and endothelial cells, the expression pattern is altered in SSc. Moreover, the expression of IL-21R appears to be independent of key cytokines that are operant in SSc.

Bucillamine induces the synthesis of vascular endothelial growth factor dose-dependently in systemic sclerosis fibroblasts via nuclear factor-kappaB and simian virus 40 promoter factor 1 pathways.

The pathogenesis of systemic sclerosis (SSc) is characterized by activation of the immune system, impaired angiogenesis, and activated dermal fibroblasts. The effects of the immunosuppressive agent bucillamine (SA 96) on fibroblasts and angiogenic factors have not been examined. SA 96, and particularly its metabolite SA 981, increased the levels of vascular endothelial growth factor (VEGF) mRNA and protein dose-dependently in dermal fibroblasts from patients with SSc and healthy control subjects without influencing cell viability. SSc fibroblast cultures showed consistently a higher inducibility of VEGF than cultures from healthy control subjects. Preincubation with the SP-1 inhibitor mithramycin as well as blockade of nuclear factor (NF)-kappaB signaling with pyrrolidine dithiocarbamate treatment and IkappaB transfection reduced significantly the transcription of VEGF, indicating that both transcription factors contribute to the activation of VEGF by SA 981. Specific binding of NF-kappaB protein to its binding site after treatment with SA 981 was confirmed by electrophoretic mobility shift assay. In contrast, SA 981 did not influence the stability of VEGF mRNA as analyzed with actinomycin D assays. The study provides evidence for a role of NF-kappaB in the transcriptional regulation of the VEGF gene. SA 96 might have positive aspects on the impaired angiogenesis in patients with SSc.

15-Deoxyspergualin in patients with refractory ANCA-associated systemic vasculitis: a six-month open-label trial to evaluate safety and efficacy.

The combination of cyclophosphamide (CYC) and oral corticosteroids is effective in the majority of patients with antineutrophil cytoplasmic antibody-associated vasculitis (AASV), but it carries substantial risk of drug-related morbidity and mortality. New regimens are desired, especially in refractory cases. The immunosuppressant 15-deoxyspergualin (DSG) is effective in experimental autoimmune disease and transplantation as well as in acute kidney transplant rejection in humans. To assess the efficacy and safety of DSG, an open label multicenter trial was conducted in patients with AASV who were either unresponsive or had contraindications for standard immunosuppressants. Included were 19 cases of Wegener granulomatosis and one case of microscopic polyangiitis. Nine of them had received CYC shortly before study entry without apparent therapeutic success. DSG (0.5 mg/kg per d) was given for 2 to 3 wk until the WBC count dropped to 3000/ micro l followed by a rest until at least a WBC of 4000/ micro l was reached again. This was repeated up to six cycles. During the study, no other immunosuppressants besides steroids were allowed. Disease improvement during treatment with DSG was achieved in 70% of cases (six cases of complete remission; eight cases of partial remission). Leucopenia occurred in each patient in a regular pattern during the cycles and was transient without exception. No mortality or septicemia was observed. Mild to moderate infections mainly in the respiratory tract were observed but resolved under adequate treatment without sequel. It is concluded that treatment with DSG is successful in patients with refractory Wegener granulomatosis under careful monitoring of WBC count.

Accumulation of histones in cell lysates precedes expression of apoptosis-related phagocytosis signals in human lymphoblasts.

Systemic lupus erythematosus (SLE) is characterized by the production of autoantibodies directed against several nuclear components, such as DNA and histones. Apoptosis was induced in activated human lymphoblasts (n = 6) by UV-B irradiation for 30 sec followed by continuous culturing. An extranuclear accumulation of the nucleosomal histones H2A, H2B, H3, and H4 in cell lysates was observed very early in the process of apoptosis, even before phosphatidylserine externalization occurred on the outer membrane surface of apoptotically dying lymphoblasts. We hypothesize that a dysregulation of apoptosis during these early phases may contribute to the induction of autoimmunity against nuclear autoantigens as seen in SLE.

Technology evaluation: adalimumab, Abbott laboratories.

Adalimumab (D2E7), a human monoclonal antibody that binds to and neutralizes TNFa, is being developed by Abbott (formerly Knoll), under license from Cambridge Antibody Technology (CAT), for the potential treatment of inflammatory disorders such as rheumatoid arthritis (RA) and Crohn's disease. It is also being investigated for the potential treatment of coronary heart disease. Phase II studies for Crohn's disease and phase III for RA were ongoing throughout 2001. Limited data are only available for RA. In January 2002, it was reported that phase III trials of adalimumab for RA had been completed, but details have not been published in the primary literature so far. At this time CAT and Abbott expected to file for US approval in the second quarter of 2002 with a launch date anticipated for 2003. Phase III data are expected to be presented at the European League Against Rheumatism meeting in June 2002. In November 2000, Lehman Brothers predicted a US launch in June 2002 with peak US sales of $600 million in 2007 and a launch in non-US markets in 2003 with peak sales in these markets of $300 million in 2008. In December 2000, Merrill Lynch predicted regulatory clearance in the second half of 2003. The probability of adalimumab reaching the market is estimated to be 70%. In December 2000, Merrill Lynch predicted a 2003 launch, with estimated sales of pounds sterling 3.65 million in that year rising to pounds sterling 30.14 million in 2010. In March 2001, ABN AMRO predicted sales of $73 million in 2003 rising to $392 million in 2007.