Successful treatment of acquired hemophilia A, complicated by chronic GVHD, with tocilizumab

Challenging treatment for refractory acquired haemophilia A complicated with severe severe acute respiratory coronavirus 2 infection

Immunosuppressive treatment and bypassing agents are used to treat acquired haemophilia A (AHA). On the other hand, COVID-19 infection induces a hypercoagulable state. Managing bleeding, risk of thrombosis, bypassing agents, active infection and immunosuppressive treatment can be challenging. A 72-year-old man was diagnosed with acquired hemophilia A. He received steroids, rituximab and recombinant activated factor VII (rFVIIa). He developed severe SARS-CoV-2 infection. Due to thrombotic risk, he received low-molecular-weight heparin (LMWH) and developed an iliopsoas hematoma. Because of the risk of thrombosis, treatment with recombinant porcine FVIII (rpFVIII) was requested. Tocilizumab was administered for treatment of SARS-CoV-2 infection and unexpected improvement of FVIII levels was noted. Concluding, rpFVIII treatment was well tolerated and effective, easy to monitor and to administer. Tocilizumab may play a role as immunosuppressive treatment for AHA. The role of LMWH remains to be established in patients with coagulopathies.

Clinicopathological features of TAFRO syndrome complicated by acquired hemophilia A and development of cardiopulmonary arrest that were successfully treated with VA-ECMO and tocilizumab

TAFRO syndrome and acquired hemophilia A (AHA) are rare, life-threatening diseases; however, the relationship between these two diseases is unknown. A 25-year-old man was transferred to our hospital because of bleeding tendency accompanied by multiple organ failure with generalized edema, massive pleural effusion, and ascites. He was diagnosed with AHA. Bypass therapy for hemostasis and cyclophosphamide with prednisolone to eradicate possible inhibitors were provided. However, he suffered from cardiopulmonary arrest. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) was initiated as rescue therapy. His hemodynamic status stabilized and he was weaned from VA-ECMO in 1 week. We confirmed normal FVIII activity and disappearance of the inhibitor, and bypass therapy was discontinued. However, generalized edema with massive ascites, pleural effusion, and renal insufficiency persisted. Bone marrow biopsy showed reticulin fibrosis. These symptoms fulfilled the diagnostic criteria of TAFRO syndrome. He received tocilizumab (TCZ) and steroid was tapered off. After four cycles of TCZ, symptoms of TAFRO syndrome gradually improved. To the best of our knowledge, this is the first report of TAFRO syndrome accompanied by AHA with rescue by VA-ECMO. Additionally, AHA and TAFRO syndrome were well controlled by TCZ.

The Two-Faced Cytokine IL-6 in Host Defense and Diseases

Interleukein-6 (IL-6), is produced locally from infectious or injured lesions and is delivered to the whole body via the blood stream, promptly activating the host defense system to perform diverse functions. However, excessive or sustained production of IL-6 is involved in various diseases. In diseases, the IL-6 inhibitory strategy begins with the development of the anti-IL-6 receptor antibody, tocilizumab (TCZ). This antibody has shown remarkable effects on Castleman disease, rheumatoid arthritis and juvenile idiopathic arthritis. In 2017, TCZ was proven to work effectively against giant cell arteritis, Takayasu arteritis and cytokine releasing syndrome, initiating a new era for the treatment of these diseases. In this study, the defensive functions of IL-6 and various pathological conditions are compared. Further, the diseases of which TCZ has been approved for treatment are summarized, the updated results of increasing off-label use of TCZ for various diseases are reviewed and the conditions for which IL-6 inhibition might have a beneficial role are discussed. Given the involvement of IL-6 in many pathologies, the diseases that can be improved by IL-6 inhibition will expand. However, the important role of IL-6 in host defense should always be kept in mind in clinical practice.

Inhibition of the interleukin-6 signaling pathway: a strategy to induce immune tolerance

Interleukin-6 (IL-6) is a proinflammatory cytokine that is multifunctional, with multifaceted effects. IL-6 signaling plays a vital role in the control of the differentiation and activation of T lymphocytes by inducing different pathways. In particular, IL-6 controls the balance between Th17 cells and regulatory T (Treg) cells. An imbalance between Treg and Th17 cells is thought to play a pathological role in various immune-mediated diseases. Deregulated IL-6 production and signaling are associated with immune tolerance. Therefore, methods of inhibiting IL-6 production, receptors, and signaling pathways are strategies that are currently being widely pursued to develop novel therapies that induce immune tolerance. This survey aims to provide an updated account of why IL-6 inhibitors are becoming a vital class of drugs that are potentially useful for inducing immune tolerance as a treatment for autoimmune diseases and transplant rejection. In addition, we discuss the effect of targeting IL-6 in recent experimental and clinical studies on autoimmune diseases and transplant rejection.

Interleukin-6 blockade in ocular inflammatory diseases

Interleukin-6 (IL-6) is a key cytokine featuring redundancy and pleiotropic activity. It plays a central role in host defence against environmental stress such as infection and injury. Dysregulated, persistent interleukin (IL)-6 production has been implicated in the development of various autoimmune, chronic inflammatory diseases and even cancers. Significant elevation of IL-6 has been found in ocular fluids derived from refractory/chronic uveitis patients. In experimental autoimmune uveitis models with IL-6 knock-out mice, IL-6 has shown to be essential for inducing inflammation. IL-6 blockade can suppress acute T helper type 17 (Th17) responses via its differentiation and, importantly, can ameliorate chronic inflammation. Tocilizumab, a recombinant humanized anti-IL-6 receptor antibody, has been shown to be effective in several autoimmune diseases, including uveitis. Herein, we discuss the basic biology of IL-6 and its role in development of autoimmune conditions, focusing particularly on non-infectious uveitis. It also provides an overview of efficacy and safety of tocilizumab therapy for ocular inflammatory diseases.

Tocilizumab: An Updated Review of Its Use in the Treatment of Rheumatoid Arthritis and Its Application for Other Immune-Mediated Diseases

Interleukin-6 (IL-6), produced by a variety of cells, is a typical cytokine featuring redundancy and pleiotropic activity. IL-6 is promptly and transiently synthesized in response to infections or injuries, and participates in host defense by inducing immune responses, hematopoiesis, and acute-phase reactions. However, since its abnormal persistent production of mostly unknown etiology plays an important pathological role in the development of various immune-mediated diseases, a humanized anti-IL-6 receptor monoclonal antibody, tocilizumab, was developed and is now used as an innovative biologic for rheumatoid arthritis in more than 90 countries. Several factors strongly suggest that a IL-6 blockade strategy may have a broad application for the treatment of various immune-mediated diseases. These factors include favorable results of pilot or case studies with off-label use of tocilizumab, pathological analyses of the contribution of IL-6 to the development of immune-mediated diseases, and the potential capability of tocilizumab to both repair an imbalance of effector T cell subsets and to suppress pathologic autoantibody production. However, clinical trials to evaluate the efficacy and safety of tocilizumab for these diseases are essential. Furthermore, clarification of the cell source of IL-6 production and of the mechanisms through which dysregulated continuous IL-6 synthesis is induced constitutes an important issue for future studies into the pathogenesis of diseases.

Immunotherapeutic implication of IL-6 blockade

IL-6 is a cytokine featuring redundancy and pleiotropic activity. While IL-6 contributes to host defense against acute environmental stress, continuous IL-6 production plays a significant pathological role in various autoimmune and chronic inflammatory diseases. To counter this drawback, tocilizumab, a humanized anti-IL-6 receptor antibody, was developed. Clinical trials have verified the efficacy of tocilizumab for patients with rheumatoid arthritis, Castleman's disease and systemic juvenile idiopathic arthritis, resulting in approval of this innovative biologic for their treatment. Moreover, a considerable number of case reports and pilot studies have indicated the beneficial effects of tocilizumab on other autoimmune and chronic inflammatory diseases. Further clinical studies to evaluate the efficacy and safety of tocilizumab for these diseases are essential.

Tocilizumab for the treatment of rheumatoid arthritis and other systemic autoimmune diseases: current perspectives and future directions

Interleukin (IL)-6 is a cytokine featuring redundancy and pleiotropic activity. While IL-6, when transiently produced, contributes to host defense against acute environmental stress, continuous dysregulated IL-6 production plays a significant pathological role in several systemic autoimmune diseases. In response to the expectation that IL-6 blockade would constitute a novel therapeutic strategy for the treatment of these diseases, tocilizumab, a humanized anti-IL-6 receptor antibody, was developed. Clinical trials have verified the efficacy and the safety of tocilizumab for patients with rheumatoid arthritis, resulting in approval of this innovative biologic for the treatment of rheumatoid arthritis in more than 90 countries worldwide. Pathological analyses of the effect of IL-6 on the development of autoimmune diseases and a considerable number of case reports and pilot studies have also indicated the beneficial effects of this antibody on other systemic autoimmune diseases, including systemic lupus erythematosus, systemic sclerosis, polymyositis, and large-vessel vasculitis.