A pilot study of combination anti-cytokine and anti-lymphocyte biological therapy in rheumatoid arthritis
Immunological tolerance in humans using anti-T-cell monoclonal antibodies (mAbs) may be hampered by a pro-inflammatory microenvironment. All clinical trials of such therapies in rheumatoid arthritis (RA), however, have selected patients with active disease at baseline. Concurrent neutralization of inflammation with a TNFalpha antagonist should maximize the potential of anti-T-cell mAbs to induce tolerance in RA.
To evaluate the safety of combining a TNFalpha antagonist and CD4 mAb in RA.
An iterative pilot study focused on the safety of such combination therapy.
Eight poor prognosis, seropositive RA patients were treated with combined CD4 and TNFalpha blockade. Prolonged CD4 blockade was achieved with a humanized mAb, and TNFalpha blockade with a p55 TNF receptor fusion protein.
There was a low incidence of classical first-dose reactions to the CD4 mAb, possibly reflecting concomitant TNFalpha blockade. An unusual anaphylactoid reaction was seen, however, and one patient developed a probable allergic reaction after several infusions. Skin rashes were common, as previously reported with CD4 mAb monotherapy. No serious infections were documented during follow-up, despite CD4+ lymphopenia in some patients. Most patients appeared to demonstrate improved RA disease control after the study. After 17-49 months after therapy, one patient was in remission, one remained off disease modifying anti-rheumatic drugs and five had stable disease, three on previously ineffective doses of methotrexate.
We report, for the first time in man, immunotherapy with a combination of an anti-cytokine and an anti-T-cell reagent. We witnessed an unusual first-dose reaction but there were no significant infectious complications.
Available from: John D Isaacs
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ABSTRACT: Accumulating evidence suggests that RA is a T-cell-mediated autoimmune disease. Early attempts at disease modulation using strategies such as CD4 mAbs were severely hampered by a lack of biomarkers of autoreactivity. Recently, however, co-stimulation blockade has emerged as an effective treatment for RA. Alongside a greatly improved mechanistic understanding of immune regulation, this has rekindled hopes for authentic and robust immune programming. The final pieces of the jigsaw are not yet in place for RA but, in other disciplines, emerging treatment paradigms such as non-mitogenic anti-CD3 mAbs, autoantigenic peptides and even cellular therapies are providing hope for a future in which immunopathology can be specifically and vigorously curtailed.
Rheumatology (Oxford, England) 06/2008; 47(10):1461-8. DOI:10.1093/rheumatology/ken163 · 4.48 Impact Factor
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ABSTRACT: Dendritic cells (DCs) are enriched in RA synovium and have been implicated in the pathogenesis of RA primarily through their ability to present autoantigen and activate T cells. However, whether DCs play an effector role in cartilage destruction is unknown. The aim of this study was to investigate whether DCs can induce collagen release from cartilage and the mechanism involved.
Human monocyte-derived DCs (mDCs) were activated with CD40 ligand (CD40L) to mimic DC-T-cell interaction, and supernatants were incubated with cartilage explants. Hydroxyproline was assessed as a measure of collagen release and collagenolytic activity was measured by a bioassay using tritiated collagen. TNF-alpha in DC supernatants was measured by specific ELISA.
Supernatants from CD40L-activated mDCs, but not unstimulated mDCs, strongly induced the destruction of cartilage collagen. mDC supernatants did not contain collagenases but did induce collagenolytic activity in cartilage explants. Neutralization of TNF-alpha in mDC supernatants completely abolished collagenolysis.
This study shows that mDCs, upon CD40-ligation, induce cartilage collagen degradation through an indirect mechanism via the production of TNF-alpha. Our data suggest a potential important role for mDC-derived TNF-alpha in RA, which is in line with the previously reported observations that DCs are a major source of TNF-alpha in early autoimmune lesions and that anti-TNF-alpha therapeutics effectively suppress joint damage in RA patients. We propose that DCs can act as effectors in cartilage destruction, adding a new aspect to the functional role of DCs in RA pathogenesis.
Rheumatology (Oxford, England) 04/2009; 48(5):502-7. DOI:10.1093/rheumatology/kep040 · 4.48 Impact Factor
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ABSTRACT: Tumour necrosis factor alpha (TNFalpha) blockade is an effective therapy for rheumatoid arthritis (RA). The immunomodulatory effects of TNFalpha antagonists are thought to contribute to their therapeutic action. This study investigated whether anti-TNFalpha therapeutics exerted their immunoregulatory effects through modulation of dendritic cell (DC) function.
Two complementary approaches were taken: in the first 'in vitro' approach monocyte-derived DC from healthy donors were matured with lipopolysaccharide and treated with TNFalpha antagonists in vitro for 48 h. In the second 'ex vivo' approach monocyte-derived DC were generated from RA patients before and 8-12 weeks into anti-TNFalpha treatment. DC were analysed for survival, phenotype, cytokine production and T-cell stimulatory capacity.
TNFalpha blockade during DC maturation in vitro induced approximately 40% of DC to undergo apoptosis. Importantly, the surviving DC displayed a semimature phenotype with reduced levels of HLA-DR, CD80, CD83, CD86 and CCR7, and their production of IL-10 was enhanced compared with DC matured without TNFalpha antagonists. Furthermore, anti-TNFalpha-treated DC were poor stimulators of T-cell proliferation and polarised T-cell development towards a higher IL-10/lower IFNgamma cytokine profile. Similarly, DC derived from RA patients after anti-TNFalpha treatment showed impaired upregulation of CD80 and CD86 upon lipopolysaccharide activation and displayed poor T-cell stimulatory activity.
The data show that TNFalpha blockade has profound effects on DC function with downstream, potentially immunoregulatory, effects on T cells. These data provide an interesting new insight into the potential mechanism by which anti-TNFalpha drugs contribute to the restoration of immunoregulation in RA patients.
Annals of the rheumatic diseases 09/2009; 69(6):1200-7. DOI:10.1136/ard.2009.110502 · 10.38 Impact Factor
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