Tocilizumab: an interleukin-6 receptor inhibitor for the treatment of rheumatoid arthritis

Evaluation of Drug-Induced Liver Injury in Hospitalized Patients with SARS-CoV-2 Infection

Elevated liver enzymes are frequently reported in SARS-CoV-2-infected patients. Several mechanisms of liver injury have been proposed, but no clear conclusions were drawn. We aimed to evaluate hepatocellular and cholestatic injury in relation to the administration of potentially hepatotoxic drugs included in the current COVID-19 therapeutic guidelines in a retrospective cohort of 396 hospitalized COVID-19 patients. The main findings of our study are: (1) Significant increase in aminotransferases level was observed during hospitalization, suggesting drug-related hepatotoxicity. (2) Tocilizumab was correlated with hepatocellular injury, including ALT values greater than five times the upper limit of normal. (3) Anakinra was correlated with ALT values greater than three times the upper limit of normal. (4) Younger patients receiving tocilizumab or anakinra had a higher risk of hepatocellular injury. (5) The combination of favipiravir with tocilizumab was associated with AST values greater than three times the upper limit of normal and with an increase in direct bilirubin. (6) The administration of at least three potentially hepatotoxic drugs was correlated with hepatocellular injury, including ALT values greater than five times the upper limit of normal, and with the increase in indirect bilirubin. (7) Remdesivir and favipiravir by themselves did not correlate with hepatocellular or cholestatic injury in our study cohort.

Interleukin-6 cytokine: An overview of the immune regulation, immune dysregulation, and therapeutic approach

Several studies have shown that interleukin 6 (IL-6) is a multifunctional cytokine with both pro-inflammatory and anti-inflammatory activity, depending on the immune response context. Macrophages are among several cells that secrete IL-6, which they express upon activation by antigens, subsequently inducing fever and production of acute-phase proteins from the liver. Moreover, IL-6 induces the final maturation of B cells into memory B cells and plasma cells as well as an adaptive role for short-term energy allocation. Activation of IL-6 receptors results in the intracellular activation of the JAK/STAT pathway with resultant production of inflammatory cytokines. Several mechanisms-controlled IL-6 expression, but aberrant production was shown to be crucial in the pathogenesis of many diseases, which include autoimmune and chronic inflammatory diseases. IL-6 in combination with transforming growth factor β (TGF-β) induced differentiation of naïve T cells to Th17 cells, which is the cornerstone in autoimmune diseases. Recently, IL-6 secretion was shown to form the backbone of hypercytokinemia seen in the Coronavirus disease 2019 (COVID-19)-associated hyperinflammation and multiorgan failure. There are two classes of approved IL-6 inhibitors: anti-IL-6 receptor monoclonal antibodies (e.g., tocilizumab) and anti-IL-6 monoclonal antibodies (i.e., siltuximab). These drugs have been evaluated in patients with rheumatoid arthritis, juvenile idiopathic arthritis, cytokine release syndrome, and COVID-19 who have systemic inflammation. JAK/STAT pathway blockers were also successfully used in dampening IL-6 signal transduction. A better understanding of different mechanisms that modulate IL-6 expression will provide the much-needed solution with excellent safety and efficacy profiles for the treatment of autoimmune and inflammatory diseases in which IL-6 derives their pathogenesis.

Tocilizumab Effect on Lipid Profile in Correlation to Cardiovascular Events: A Retrospective Cohort Study

Objective

To study the effect of tocilizumab initiation on the lipid profile, in correlation to a composite of any cardiovascular events.

Methods

A retrospective cohort study, using data from the King Faisal Specialist Hospital & Research Centre database, from January 2014 to December 2019. Patients with rheumatoid arthritis or juvenile idiopathic arthritis who were ≥18 years old, initiated either on tocilizumab or other biologic treatment (anti-TNFs or Rituximab), were included, with a follow-up interval duration at a minimum of 6–12 months up to 3-5 years. Any patient with established cardiovascular disease or aged <18 were excluded.

Results

Only one cardiovascular mortality was reported in the tocilizumab group. Fifty percent of patients reached high cholesterol levels ≥ 5.2 mmol/L and LDL ≥ 3.37 mmol/L in the tocilizumab group at 36 months in a shorter time period compared to controls (60 months), P 0.001. There were no significant differences between groups for statin use (27% vs. 28%) However, there was a significantly higher mean dose of atorvastatin in the tocilizumab group compared to controls (20.6 mg vs. 16.6 mg, P 0.03).

Conclusion

There was a lack of evidence of increased cardiovascular risk in correlation to hyperlipidemia secondary to tocilizumab treatment.

Editorial: Tocilizumab, a Humanized Therapeutic IL-6 Receptor (IL-6R) Monoclonal Antibody, and Future Combination Therapies for Severe COVID-19

Vaccinated, non-vaccinated, and immunosuppressed individuals will continue to be infected with SARS-CoV-2. Therefore, there is a priority to develop treatments that reduce the severity of COVID-19 in patients who require hospital admission. Interleukin-6 (IL-6) is a proinflammatory cytokine. In 2011, a humanized monoclonal antibody to the IL-6 receptor (IL-6R), tocilizumab, was approved by the US Food and Drug Administration (FDA) for the treatment of rheumatoid arthritis, juvenile idiopathic arthritis, giant cell arteritis, and Castleman's disease. In 2017, tocilizumab was approved to treat chimeric antigen receptor (CAR) T-cell therapy-induced cytokine release syndrome (CRS). In 2021, the results of the REMAP-CAP clinical trial (NCT02735707) and the COVID-19 Therapy (RECOVERY) clinical trial (NCT04381936) supported FDA Emergency Use Authorization (EUA) for tocilizumab to treat hospitalized patients with moderate and severe COVID-19. Monoclonal antibodies are currently in clinical development or undergoing clinical trials to treat COVID-19. Further clinical trials will provide safety and efficacy data on targeting IL-6 and IL-6R and provide rationales for more personalized combination treatments to control the systemic effects of SARS-CoV-2 infection in hospitalized patients with moderate and severe COVID-19. This Editorial aims to present the background to the recent authorization of tocilizumab, a humanized therapeutic monoclonal antibody to the IL-6 receptor (IL-6R), for hospitalized patients with moderate and severe COVID-19 and future combination therapies.

Effects of tocilizumab versus hemoadsorption combined with tocilizumab in patients with SARS-CoV-2 pneumonia: Preliminary results

OBJECTIVE

To assess the variations of Interleukin-6 (IL-6) in patients with SARS-CoV-2 infection treated with Tocilizumab (TCZ) alone or in association with hemoadsorption (HA).

DESIGN

Retrospective.

SETTING

An Intensive Care Unit (ICU) admitting mechanically ventilated patients with SARS-CoV-2 pneumonia.

PATIENTS

Four adult patients.

INTERVENTIONS

We compared the blood values of IL-6, C-reactive protein (CRP) and of other biochemical variables including the PaO₂/FiO₂ in two patients who received TCZ alone and in other 2 in whom it was associated with the HA (TCZ-HA) due to the presence of impending or established organ failures other than the lung. All variables were measured before, during and after the treatment.

MAIN RESULTS

In all patients, the IL-6 increased during the treatment; after its termination, its values sharply decreased only in those treated also with HA; conversely, the CRP decreased in all patients; the PaO₂/FiO₂ increased in three patients and remained stable in the remaining one. Both the TCZ and the HA were well tolerated; all patients were weaned from the mechanical ventilation and discharged from the hospital.

LIMITATIONS

Although the limited number of patients does not allow to draw firm conclusions, the increase of the IL-6 of can be ascribed to its displacement from cellular and soluble receptors, whereas its decrease is likely due to the scavenging effect exerted by the HA. Although the association TCZ-HA could be valuable in the treatment of the Cytokine Release Storm (CRS) associated with the SARS-CoV-2, the HA could be more effective as it neutralizes a wider panel of inflammatory mediators.

Novel Role of T Cells and IL-6 (Interleukin-6) in Angiotensin II-Induced Microvascular Dysfunction

Hypertension is an established risk factor for subsequent cardiovascular diseases, with Ang II (angiotensin II) playing a major role in mediating thrombotic and inflammatory abnormalities. Although T cells and IL-6 (interleukin-6) play an important role in adaptive immune responses, little is known about their role(s) in the thromboinflammatory responses associated with Ang II. Here we show using intravital microscopy coupled with the light/dye injury model that Rag-1 deficient (Rag-1-/-) and IL-6 deficient (IL-6-/-) mice are afforded protection against Ang II-induced thrombosis. Blocking IL-6 receptors (using CD126 and gp130 antibodies) significantly diminished Ang II-mediated thrombosis and inflammatory cell recruitment in mice. Furthermore, the adoptive transfer of IL-6-/--derived T cells into Rag-1-/- mice failed to accelerate Ang II-induced thrombosis compared with Rag-1-/- mice reconstituted with wild-type-derived T cells, suggesting T cell IL-6 mediates the thrombotic abnormalities associated Ang II hypertension. Interestingly, adoptive transfer of WT T cells into Rag-1-/-/Ang II mice resulted in increased numbers of immature platelets, which constitutes a more active platelet population, that is, prothrombotic and proinflammatory. To translate our in vivo findings, we used clinical samples to demonstrate that IL-6 also predisposes platelets to an interaction with collagen receptors, thereby increasing the propensity for platelets to aggregate and cause thrombosis. In summary, we provide compelling evidence for the involvement of IL-6, IL-6R, and T-cell-dependent IL-6 signaling in Ang II-induced thromboinflammation, which may provide new therapeutic possibilities for drug discovery programs for the management of hypertension.

Identification of differential co-expressed gene networks in early rheumatoid arthritis achieving sustained drug-free remission after treatment with a tocilizumab-based or methotrexate-based strategy

BACKGROUND

Methotrexate is endorsed to be used as first-line treatment in rheumatoid arthritis (RA). However, a large proportion of patients need additional treatment with a biological disease-modifying anti-rheumatic drug (DMARD) to adequately suppress their disease activity. A better understanding of genotypes could help to distinguish between patients with different pathogenic mechanisms. The aim of this study was therefore to identify networks of genes within DMARD-naive early RA patients associated with achieving sustained drug-free remission (sDFR) after initiating tocilizumab plus methotrexate, tocilizumab, or methotrexate therapy.

METHODS

Samples were used from 60 patients from the U-Act-Early study who received tocilizumab plus methotrexate, tocilizumab, or methotrexate therapy, and who achieved sDFR (≥3 months in drug-free remission until the end of the study, n = 37) after therapy was tapered and subsequently stopped, or who were not able to discontinue the therapy as controls (n = 23). Whole blood samples were collected and ribonucleic acid (RNA) was isolated from positive cluster of differentiation 4 (CD4⁺) and CD14⁺ cells and analysed using high-throughput sequencing. Weighted gene co-expression network analyses were performed to identify clusters (i.e. modules) of differently expressed genes associated with achieving sDFR and which were subsequently used for pathway analyses.

RESULTS

Network analyses within CD4⁺ cells identified two significant modules in the tocilizumab plus methotrexate arm and four modules in the tocilizumab and methotrexate arms, respectively (p ≤ 0.039). Important pathways in the module best correlating with achieving sDFR were in the tocilizumab plus methotrexate arm related to processes involved with transcription and translation; in the tocilizumab arm, pathways were related to migration of white blood cells and G-protein coupled receptors, and in the methotrexate arm pathways were involved with the response to a bacterial or biotic (i.e. biological material)-related stimulus. No relevant networks could be identified in the sequenced CD14⁺ cells.

CONCLUSIONS

Within networks of co-expressed genes, several pathways were found related to achieving sDFR after initiating therapy with tocilizumab, methotrexate, or the combination. Between the three strategy arms, we identified different networks of predisposing genes which indicates that specific gene expression profiles, depending on the treatment strategy chosen, are associated with a higher chance of achieving sDFR.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT01034137 . Registered on 16 December 2009.

New targets for mucosal healing and therapy in inflammatory bowel diseases

Healing of the inflamed mucosa (mucosal healing) is an emerging new goal for therapy and predicts clinical remission and resection-free survival in inflammatory bowel diseases (IBDs). The era of antitumor necrosis factor (TNF) antibody therapy was a remarkable progress in IBD therapy and anti-TNF agents led to mucosal healing in a subgroup of IBD patients; however, many patients do not respond to anti-TNF treatment highlighting the relevance of finding new targets for therapy of IBD. In particular, current studies are addressing the role of other anticytokine agents including antibodies against interleukin (IL)-6R, IL-13, and IL-12/IL-23 as well as new anti-inflammatory concepts (regulatory T cell therapy, Smad7 antisense, Jak inhibition, Toll-like receptor 9 stimulation, worm eggs). In addition, blockade of T-cell homing via the integrins α4β7 and the addressin mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) emerges as a promising new approach for IBD therapy. Here, new approaches for achieving mucosal healing are discussed as well as their implications for future therapy of IBD.

Biologic therapies and systemic bone loss in rheumatoid arthritis

Chronic inflammation affects bone metabolism leading to disequilibrium in the rates of bone resorption and repair and subsequently to local and generalized bone loss. Osteoporosis represents an important co-morbidity of rheumatoid arthritis (RA) patients, which exhibit increased fracture risk. Osteoclasts play a pivotal role in the development and progression of bone loss, while resident synovial cells such as T cells, monocytes and synovial fibroblasts have been identified as sources of osteoclast differentiation signals in RA. This process is mainly mediated through the receptor activator of nuclear-kappa B ligand (RANKL) signalling system, which is upregulated by numerous proinflammatory cytokines involved in the pathogenesis of RA. Improved knowledge of the association between cells and cytokines of the immune system and their relationship to bone remodeling has revealed several promising targets for the treatment of inflammatory bone loss in RA. In this respect, initiation of biologic therapies targeting inflammatory cytokines and/or lymphocyte activation has modified RA therapy not only by blocking local and systemic inflammatory cascades but also by providing beneficial effects against bone and joint degradation. In this article we briefly present the modern view of the mechanisms that govern inflammatory bone loss, highlighting the role of cytokine-induced molecular pathways, and discuss in detail the effects of different biologic treatment strategies on bone mass in RA patients.

IL-6 receptor is a possible target against growth of metastasized lung tumor cells in the brain

In the animal model of brain metastasis using human lung squamous cell carcinoma-derived cells (HARA-B) inoculated into the left ventricle of the heart of nude mice, metastasized tumor cells and brain resident cells interact with each other. Among them, tumor cells and astrocytes have been reported to stimulate each other, releasing soluble factors from both sides, subsequently promoting tumor growth significantly. Among the receptors for soluble factors released from astrocytes, only IL-6 receptor (IL-6R) on tumor cells was up-regulated during the activation with astrocytes. Application of monoclonal antibody against human IL-6R (tocilizumab) to the activated HARA-B cells, the growth of HARA-B cells stimulated by the conditioned medium of HARA-B/astrocytes was significantly inhibited. Injecting tocilizumab to animal models of brain metastasis starting at three weeks of inoculation of HARA-B cells, two times a week for three weeks, significantly inhibited the size of the metastasized tumor foci. The up-regulated expression of IL-6R on metastasized lung tumor cells was also observed in the tissue from postmortem patients. These results suggest that IL-6R on metastasized lung tumor cells would be a therapeutic target to inhibit the growth of the metastasized lung tumor cells in the brain.

Genetics of asthma susceptibility and severity

This article summarizes major findings in genome-wide studies of asthma susceptibility and severity. Two large meta-analyses identified four chromosomal regions which were consistently associated with development of asthma. Genes that are associated with asthma subphenotypes such as lung function, biomarker levels, and asthma therapeutic responses can provide insight into mechanisms of asthma severity and disease progression. Future genetic studies will incorporate sequencing in comprehensively phenotyped asthmatics to lead to the development of personalized therapy.

TNFα inhibits the development of osteoclasts through osteoblast-derived GM-CSF

Inflammatory cytokines such as tumor necrosis factor-alpha (TNFα) are potent stimulators of osteoclast formation and bone resorption and are frequently associated with pathologic bone metabolism. The cytokine exerts specific effects on its target cells and constitutes a part of the cellular microenvironment. Previously, TNFα was demonstrated to inhibit the development of osteoclasts in vitro via an osteoblast-mediated pathway. In the present study, the molecular mechanisms of the inhibition of osteoclastogenesis were investigated in co-cultures of osteoblasts and bone marrow cells (BMC) and in cultures of macrophage-colony stimulating factor (M-CSF) dependent, non-adherent osteoclast progenitor cells (OPC) grown with M-CSF and receptor activator of NF-κB ligand (RANKL). Granulocyte-macrophage colony stimulating factor (GM-CSF), a known inhibitor of osteoclastogenesis was found to be induced in osteoblasts treated with TNFα and the secreted protein accumulated in the supernatant. Dexamethasone (Dex), an anti-inflammatory steroid, caused a decrease in GM-CSF expression, leading to partial recovery of osteoclast formation. Flow cytometry analysis revealed that in cultures of OPC, supplemented with 10% conditioned medium (CM) from osteoblasts treated with TNFα/1,25(OH)(2)D(3), expression of RANK and CD11c was suppressed. The decrease in RANK expression may be explained by the finding, that GM-CSF and the CM from wt osteoblasts were found to suppress the expression of c-Fos, Fra-1, and Nfatc-1. The failure of OPC to develop into CD11c(+) dendritic cells suggests that cell development is not deviated to an alternative differentiation pathway, but rather, that the monocytes are maintained in an undifferentiated, F4/80(+), state. The data further implies possible interactions among inflammatory cytokines. GM-CSF induced by TNFα acts on early hematopoietic precursors, inhibiting osteoclastogenesis while acting as the growth factor for M-CSF independent inflammatory macrophages. These in turn may condition a microenvironment enhancing osteoclast differentiation and bone resorption upon migration of the OPC from circulation to the bone/bone marrow compartment.

Antibody-based therapies in multiple myeloma

The unmet need for improved multiple myeloma (MM) therapy has stimulated clinical development of monoclonal antibodies (mAbs) targeting either MM cells or cells of the bone marrow (BM) microenvironment. In contrast to small-molecule inhibitors, therapeutic mAbs present the potential to specifically target tumor cells and directly induce an immune response to lyse tumor cells. Unique immune-effector mechanisms are only triggered by therapeutic mAbs but not by small molecule targeting agents. Although therapeutic murine mAbs or chimeric mAbs can cause immunogenicity, the advancement of genetic recombination for humanizing rodent mAbs has allowed large-scale production and designation of mAbs with better affinities, efficient selection, decreasing immunogenicity, and improved effector functions. These advancements of antibody engineering technologies have largely overcome the critical obstacle of antibody immunogenicity and enabled the development and subsequent Food and Drug Administration (FDA) approval of therapeutic Abs for cancer and other diseases.

Loss of tumoral expression of soluble IL-6 receptor is associated with disease progression in colorectal cancer

Background:

Interleukin-6 (IL-6) binds both the membrane and soluble forms of the IL-6 receptor (sIL-6R), which induces a complex with gp130, and proliferation of tumour cells. The aim of this study is to clarify the relationship between tumoral sIL-6R expression and disease progression in colorectal cancer patients.

Methods:

We measured tissue concentrations of sIL-6R in tumour and normal mucosa from 161 colorectal cancer patients undergoing surgery, and in supernatants from colon cancer cell lines. The expression of IL-6, IL-6R and gp130 was evaluated by immunohistochemical analysis.

Results:

Loss of tumour expression of sIL-6R as defined by sIL-6R Ca/N ratio <1.0 was significantly associated with factors reflecting disease progression, and was an independent prognostic factor not only in all the patients in this study, but also in the patients with curative intent. Colon cancer cell lines produced sIL-6R in vitro, and the production of sIL-6R in cancer cell lines was stimulated by cytokine stimulation. Immunohistochemistry revealed that loss of tumour expression of sIL-6R was significantly inversely correlated with intense IL-6 expression in the cytoplasm of cancer cells. In addition, tumoral IL-1β expression was significantly correlated with sIL-6R expression.

Conclusion:

Loss of tumour expression of sIL-6R is associated with colorectal cancer disease progression.

Conservative treatments for rheumatoid arthritis in the foot and ankle

Rheumatoid arthritis (RA) is a systemic inflammatory disease that attacks peripheral joints, causing their destruction. Several pharmacologic therapies and physical modalities are available for its treatment. Because of the progressive nature of RA, complementary and alternative medicine therapy in conjunction with conventional medicine is administered to patients with RA. This article discusses the presence of undiagnosed RA in the foot and ankle and reviews the concurrent nonoperative measures in treatment, including pharmacologic and physical modalities.

Golimumab: A Tumor Necrosis Factor Alpha Inhibitor for the Treatment of Rheumatoid Arthritis

OBJECTIVE

To review the pharmacologic, pharmacokinetic, efficacy, and safety data of golimumab, an anti-tumor necrosis factor alpha (TNF-α) monoclonal antibody.

DATA SOURCES

A search of MEDLINE (1950-September 2009) was performed to identify any published clinical trials or review articles pertaining to golimumab. Key search terms included golimumab, rheumatoid arthritis, CNTO 148, and anti-TNF-α inhibitors. Bibliographies of selected articles were reviewed to identify other relevant citations. Abstracts from national and international meetings and information from the manufacturer were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

All available published articles and abstracts describing golimumab's pharmacologic or pharmacokinetic profile, efficacy, and safety were included.

DATA SYNTHESIS

Golimumab is a fully humanized TNF-α monoclonal antibody that is specific for human TNF-α. Trials have investigated the use of golimumab in patients who have rheumatoid arthritis (RA) and are on methotrexate, are methotrexate-naïve, and have previously tried TNF-α inhibition therapy. When used in combination with methotrexate or another disease-modifying antirheumatic drug, golimumab therapy results in improvements of clinical outcomes including the American College of Rheumatology parameters in all of the aforementioned populations. Although multiple doses and dosing regimens have been studied, the Food and Drug Administration-approved dose is 50 mg subcutaneously every 4 weeks. The most common adverse effects include injection site erythema, headaches, and nausea. There were a limited number of incidences of serious infection or malignancy.

CONCLUSIONS

With 4 TNF-α monoclonal antibodies currently on the market, it is unclear what golimumab's place in therapy for RA will be. Some benefits include monthly injections, proven efficacy after previous TNF-α inhibitor therapy, and limited antibody development during therapy. However, with a lack of longer-term trials assessing efficacy and safety compared with other TNF-α inhibitors, golimumab should be reserved for use after other therapies fail.

Bioboosters in the treatment of rheumatic diseases: a comprehensive review of currently available biologics in patients with rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis

Immunologic research has clarified many aspects of the pathogenesis of inflammatory rheumatic disorders. Biologic drugs acting on different steps of the immune response, including cytokines, B- and T-cell lymphocytes, have been marketed over the past 10 years for the treatment of rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA). Randomized controlled trials (RCTs) of anti-cytokine agents in RA (including the anti-tumor necrosis factor alpha (TNFα) drugs infliximab, etanercept, adalimumab, golimumab, certolizumab, anti-interleukin (IL)-1 anakinra, and anti-IL-6 tocilizumab) demonstrated a significant efficacy compared to traditional therapies, if combined with methotrexate (MTX), as measured by ACR 20, 50 and 70 response criteria. The new therapies have also been demonstrated to be superior to MTX in slowing or halting articular damage. RCTs have shown the efficacy of anti-TNFα in AS patients through significant improvement of symptoms and function. Trials of anti-TNFα in PsA patients showed marked improvement of articular symptoms for psoriasis and radiological disease progression. More recent studies have demonstrated the efficacy of B-cell depletion with rituximab, and T-cell inactivation with abatacept. All these drugs have a satisfactory safety profile. This paper reviews the different aspects of efficacy and tolerability of biologics in the therapy of RA, AS, and PsA.

Novel targeted therapies for autoimmunity

The emergence of new targeted therapies is rapidly improving the treatment of autoimmune disease. These drugs have been variably designed to deplete specific T and B cell subsets, interrupt receptor-ligand interactions, and inhibit the activity of inflammatory mediators relevant to immune function. Abatacept, a co-stimulatory blocker, and rituximab, a B cell depleting antibody, are among the approved therapies seeking new indications, while the newer therapies include Fc receptor-non-binding CD3-specific antibodies, IL-12/23 antibodies, an IL-6 receptor antagonist, a sphingosine-1-phosphate agonist, and small molecule inhibitors of intracellular protein kinases. Antigen-specific therapies are in their infancy, but the latest results administering glutamic acid dehydrogenase peptide to type 1 diabetics are promising. In the future, treatment strategies may increasingly explore the use of drug combinations acting at multiple sites of aberrant immunoregulation to achieve disease quiescence and immune tolerance.

Understanding autoimmune disease: new targets for drug discovery

A more complete understanding of the mechanisms that drive autoimmune diseases has begun to be translated into therapeutic options with significant clinical consequences. A clear example of this is the introduction of biological therapies, which have provided new therapeutic avenues, as well as validated the mediators (TNFalpha, IL-6), mechanisms (T cell costimulation, leukocyte migration), and cellular players (T and B lymphocytes) of the disease process itself. New discoveries into the role of Th17 and regulatory T cells and the epigenetic regulation of cytokine expression may offer novel intervention strategies to satisfy the unmet medical needs that still exist in these diseases.