Tocilizumab in isolated polymyalgia rheumatica: A systematic literature review.

OBJECTIVE: We investigated the effectiveness of tocilizumab (an anti-interleukin-6 receptor antibody) in patients with polymyalgia rheumatica (PMR). METHODS: We performed a systematic literature review from the inception dates until August 7, 2019 for articles reporting tocilizumab administration to treat isolated PMR. RESULTS: We identified 59 patients with isolated PMR treated with tocilizumab. All studies used intravenously administered tocilizumab at a dose of 8 mg/kg monthly. Tocilizumab monotherapy was administered to 24 and combination therapy (tocilizumab + glucocorticoid) to 35 patients. Tocilizumab monotherapy achieved low disease activity scores in only 17% of patients at week 4 and in only 71% patients even at week 12. Compared to glucocorticoid monotherapy, the reduction in the cumulative glucocorticoid dose was between 58% and 70% using a combination of tocilizumab and glucocorticoids, and 33-100% of the patients eventually showed glucocorticoid-free remission. All relapses occurred in patients administered tocilizumab monotherapy. No new safety event was reported. CONCLUSION: Tocilizumab is effective in cases of isolated PMR, particularly in combination with glucocorticoids. In addition to its glucocorticoid-sparing effect, it achieves glucocorticoid-free remission and reduces relapse rates. Tocilizumab monotherapy is not recommended.

Spinal Inhibition of P2XR or p38 Signaling Disrupts Hyperalgesic Priming in Male, but not Female, Mice.

Recent studies have demonstrated sexual dimorphisms in the mechanisms contributing to the development of chronic pain. Here we tested the hypothesis that microglia might preferentially regulate hyperalgesic priming in male mice. We based this hypothesis on evidence that microglia preferentially contribute to neuropathic pain in male mice via ionotropic purinergic receptor (P2XR) or p38 mitogen-activated protein kinase (p38) signaling. Mice given a single-priming injection of the soluble human interleukin-6 receptor (IL-6r) and then a second injection of prostaglandin E2 (PGE2), which unmasks hyperalgesic priming, shows a significant increase in levels of activated microglia at 3 h following the PGE2 injection in both male and female mice. There was no change in microglia following PGE2. Intrathecal injection of the P2X3/4 inhibitor TNP-ATP blocked the initial response to IL-6r in both males and females, but only blocked hyperalgesic priming in male mice. Intrathecally applied p38 inhibitor, skepinone, had no effect on the initial response to IL-6r but attenuated hyperalgesic priming in males only. Neither TNP-ATP nor skepinone could reverse priming once it had already been established in male mice suggesting that these pathways must be inhibited early in the development of hyperalgesic priming to have an effect. Our work is consistent with previous findings that P2XR and p38 inhibition can lead to male-specific effects on pain behaviors in mice. However, given that we did not observe microglial activation at time points where these drugs were effective, our work also questions whether these effects can be completely attributed to microglia.

Combined XIL-6R and urocortin-2 treatment restores MDX diaphragm muscle force.

INTRODUCTION: Duchenne muscular dystrophy (DMD) is characterized by progressive muscle degeneration leading to immobility, respiratory failure, and premature death. As chronic inflammation and stress are implicated in DMD pathology, the efficacy of an anti-inflammatory and anti-stress intervention strategy in ameliorating diaphragm dysfunction was investigated. METHODS: Diaphragm muscle contractile function was compared in wild-type and dystrophin-deficient mdx mice treated with saline, anti-interleukin-6 receptor antibodies (xIL-6R), the corticotrophin-releasing factor receptor 2 (CRFR2) agonist, urocortin 2, or both xIL-6R and urocortin 2. RESULTS: Combined treatment with xIL-6R and urocortin 2 rescued impaired force in mdx diaphragms. Mechanical work production and muscle shortening was also improved by combined drug treatment. DISCUSSION: Treatment which neutralizes peripheral IL-6 signaling and stimulates CRFR2 recovers force-generating capacity and the ability to perform mechanical work in mdx diaphragm muscle. These findings may be important in the search for therapeutic targets in DMD. Muscle Nerve 56: E134-E140, 2017.

Concentración de interleuquina-6 en el vítreo de pacientes con desprendimiento de retina / Interleukin-6 concentrations in the vitreous body of patients with retinal detachment

OBJETIVO: Determinar los niveles de interleuquina-6 (IL-6) en el vítreo de pacientes con desprendimiento de retina (DdR). MATERIAL Y MÉTODO: Mediante vitrectomía vía pars plana, se recogieron muestras no diluidas de vítreo de 40 pacientes sin antecedentes de cirugía vítrea o intraocular previa, que fueron divididos en 2 grupos: A (n = 20) pacientes con DdR y B (n = 20) pacientes con membrana premacular y agujero macular. La concentración de IL-6 se determinó mediante radioinmunoensayo. RESULTADOS: La concentración vítrea de IL-6 en el grupo A fue 122,4 + -16 pg/mL (rango 91,5-620) y en el grupo B fue 46 +/- 23 pg/mL (rango 3-150) (p < 0,001). CONCLUSIONES: Estos resultados demuestran que la concentración vítrea de IL-6 está más elevada en los pacientes con DdR en comparación con el grupo control

OBJECTIVE: To measure interleuquin-6 (IL-6) levels in the vitreous body of patients with retinal detachment (RD). PATIENTS AND METHODS: Undiluted vitreous samples were obtained from 40 patients with no history of prior vitreous or intraocular surgery. Patients were divided into two groups: A (n = 20) patients with RD and B (n = 20) patients with pre-retinal macular membranes and macular holes. IL-6 was determined using radioimmunoassay. RESULTS: IL-6 vitreous concentration in group A was 122.4 + -16 pg/mL (range 91.5-620) and in group B was 46 +/- 23 pg/mL (range 3-150) (p < .001). CONCLUSIONS: These results show that the concentration of IL-6 in the vitreous body was significantly higher in patients with RD than in the control group

Whole Cell Therapeutic Vaccine Modified With Hyper-IL6 for Combinational Treatment of Nonresected Advanced Melanoma.

UNLABELLED: Active specific immunotherapy of cancer requires an efficient induction and effector phase. The induction covers potent activation of anti-tumor response, whereas effector breaks the immunosuppression. We report efficacy of therapeutic melanoma vaccine (AGI-101H) used alone in advanced disease as a candidate for further combined treatment. In adjuvant setting in patients with resected metastases AGI-101H combined with surgery of recurring disease demonstrated long-term survival. Seventy-seven patients with nonresectable melanoma (8% IIIB, 21% IIIC, 71% IV) were enrolled. AGI-101H was administered 8× every 2 weeks, and then every month. At progression, maintenance was continued or induction was repeated and followed by maintenance. Median follow-up was 139.3 months. The median overall survival (OS) was 17.3 months; in patients with WHO 0-1 was 20.3 months. Complete response (CR) and partial response (PR) were observed in 19.4% and 9% of pts. Disease control rate was 54.5% of pts. The median CR+PR duration was 32 months. Reinduction was performed in 36.3% patients following disease progression with 46.6% of CR+PR. No grade 3/4 adverse events were observed. Treatment with AGI-101H of melanoma patients is safe and effective. AGI-101H is a good candidate for combinatorial treatment with immune check-points inhibitors or tumor hypoxia normalizators. TRIAL REGISTRATION: EudraCT Number 2008-003373-40.

IL6 trans-signaling promotes functional recovery of hypofunctional phagocytes through STAT3 activation during peritonitis.

OBJECTIVE: The role of high interleukin 6 (IL6) levels has not been clearly explained in severe sepsis. We show that the augmentation of the IL6 signal by recombinant IL6 receptors (rIL6R) delivery allows the functional recovery of phagocytes in a peritonitis mouse model. MATERIALS AND METHODS: Mice were challenged intraperitoneally (i.p.) with live Staphylococcus aureus for effect of IL6R delivery on the 24 h-survival, bacterial clearance and cellular responses. In additional experiments to assess the effect of IL6R delivery on phagocytosis, the model was i.p. inoculated with heat-killed S. aureus with or without rIL6R and the peritoneal lavage fluid and cells were collected at 1 h after the i.p. inoculation of S. aureus. RESULTS: The IL6R delivery tended to improve 24 h survival and increase bacteria clearance from the septic mice. The rIL6R treatment to heat-killed bacteria challenged mice augmented the uptake of bacteria and phagosome acidification, inducing the phosphorylation of STAT3 in peritoneal cells within 1 h after the IL6R delivery. Furthermore, the rIL6R delivery prevented the extracellular release of neutrophil elastase activity and myeloperoxidase (harmful factors). CONCLUSIONS: These results indicate that augmentation of IL6 signaling appears to be critical for the effective management of hypofunctional neutrophils during severe inflammation, such as sepsis.

Targeting interleukin-6 in rheumatoid arthritis.

Interleukin (IL)-6 is a potent pro-inflammatory agent that plays a crucial role in the pathogenesis of systemic inflammatory disease. Targeting this pathway in rheumatoid arthritis (RA) seems an attractive option as IL-6 is important for both joint destruction and systemic manifestations. Currently, tocilizumab, which binds the IL-6 receptor, is licensed for treatment in active, moderate to severe disease in RA and systemic juvenile idiopathic arthritis (JIA). Several other promising IL-6 blocking agents as well as a subcutaneous form of tocilizumab are currently undergoing phase III clinical trials. The aim of this article is to provide an up-to-date analysis of clinical efficacy and tolerability data concerning the use of IL-6 inhibitors. Data from clinical trials demonstrated that clinical efficacy for tocilizumab, which included improvement in physical function and halting radiographic progression, were comparable to other biologics licensed for use in RA. Patients who should gain most are RA patients with systemic features such as high inflammatory markers and anaemia. Perhaps, the strongest selling point lies in its effectiveness as a monotherapy. This is particularly useful in those who are not tolerating combination treatment with methotrexate. Tocilizumab is one of a few biologics that have been shown to be superior to methotrexate in head-to-head studies. The safety profile of tocilizumab also is comparable to other currently available biologics. There is a small but significant increase in adverse events including infections in patients treated with tocilizumab compared to placebo, particularly in patients who are elderly and those with multiple comorbidities. Elevated lipid profiles are frequent but have not been associated with major cardiovascular events. IL-6 blockade is a major advancement in the treatment of RA as it targets a unique molecule. Over the next few years, evidence will be available on the long-term cardiovascular safety and efficacy of subcutaneous IL-6 blocking agents.

Soluble interleukin-6 receptor induces motor stereotypies and co-localizes with gp130 in regions linked to cortico-striato-thalamo-cortical circuits.

Soluble cytokine receptors are normal constituents of body fluids that regulate peripheral cytokine and lymphoid activity and whose levels are increased in states of immune activation. Soluble interleukin-6 receptor (sIL-6R) levels positively correlate with disease progression in some autoimmune conditions and psychiatric disorders. Particularly strong links between levels of sIL-6R and the severity of psychotic symptoms occur in schizophrenia, raising the possibility that sIL-6R is involved in this disease. However, there is no evidence that peripheral sIL-6R induces relevant behavioral disturbances. We showed that single subcutaneous injections of sIL-6R (0-1 µg), stimulated novelty stress-induced exploratory motor behaviors in male Balb/c mice within 20-40-min of injection. A progressive increase in vertical stereotypies was observed 40-80 min post injection, persisting for the remainder of the test session. Paralleling these stimulant-like effects, sIL-6R pre-treatment significantly enhanced stereotypy scores following challenge with GBR 12909. We found that peripherally administered sIL-6R crossed the blood-brain barrier, localizing in brain regions associated with cortico-striatal-thalamo-cortical (CSTC) circuits, which are putative neuroanatomical substrates of disorders associated with repetitive stereotypies. Peripherally administered sIL-6R co-localized with gp130, a transmembrane protein involved in IL-6 trans-signaling, in the nucleus accumbens, caudate-putamen, motor and infralimbic cortices, and thalamic nuclei, but not with gp130 in the ventral tegmental area, substantia nigra, or sensorimotor cortex,. The results suggest that peripheral sIL-6R can act as a neuroimmune messenger, crossing the blood brain barrier (BBB) to selectively target CSTC circuits rich in IL-6 trans-signaling protein, and inducing repetitive stereotypies. As such sIL-6R may represent a novel therapeutic agent for relevant psychiatric disorders.

Fracture repair: modulation of fracture-callus and mechanical properties by sequential application of IL-6 following PTH 1-34 or PTH 28-48.

Fracture healing presents a sequence of three major stages: inflammation and granulation tissue formation, callus formation and remodeling. Our working hypothesis was that fracture-repair might be enhanced by stimulating proliferation of chondrocytes and osteoblasts in the early stages of fracture healing followed by sequential acceleration of the remodeling process. In the present study we employed a novel device developed by us implementing a standardized fracture in rat tibiae. We investigated the effect of PTH 28-48 or PTH 1-34 alone or in sequence combination with IL-6 together with its soluble receptor (IL-6sR) on fracture repair. PTH 28-48 or PTH 1-34 was applied locally into the hematoma of fractures on days 4, 5 and 6 and IL-6+ its soluble receptor on days 7, 9, and 11. Post-fracture callus volume as measured 14 days post-fracture was increased significantly only by PTH 1-34 (20%; P<0.01). When one of the PTH fragments and IL-6+IL-6sR were applied sequentially callus volume was increased significantly (33%; P<0.01). X-rays radiography at 5 weeks post-fracture showed enlarged callus volume following treatment by either PTH fragments alone, and complete union following the sequential injection of both PTH fragments and IL-6+IL-6sR, only. Only the combination of one of the PTH fragments with IL-6+IL-6sR, as measured 6 weeks post-fracture by three point bending, changed dramatically the quality of the regenerating bone as presented by a 300% increase in mechanical resistance when PTH 1-34 was combined and 200% when PTH 28-48 was combined relative to vehicle-treated fractured bones. We conclude that the sequential application of IL-6+IL-6sR with both PTH fragments has the potential of enhancing fracture healing in long bones and should be further explored in preclinical and in clinical studies.

Local delivery of soluble interleukin-6 receptors to improve the outcome of alpha-toxin producing Staphylococcus aureus infection in mice.

Staphylococcal alpha-toxin enhances interleukin (IL)-6 secretion in mice infected with Staphylococcus aureus. The role of alpha-toxin-induced IL-6 secretion in host defense has not been sufficiently clarified. In the present study, IL-6 signaling was transiently regulated using soluble IL-6 receptors (sIL-6R) to investigate the role of IL-6 in the early stage of abdominal S. aureus infection. In mice challenged with bacteria producing high alpha-toxin levels, the local delivery of sIL-6R was effective in improving the survival rate, the resolution of neutrophilia and the bacteria clearance. Mice that had received sIL-6R and survived showed high levels of IL-6, monocyte chemoattractant protein (MCP)-1 and tumor necrosis factor (TNF)-alpha. In contrast, mice that died in spite of the delivery of sIL-6R showed high levels of interferon (IFN)-gamma and IL-1alpha and low TNF-alpha level. When the effect of soluble gp130, a sIL-6R antagonist, was examined, the number of neutrophils increased significantly and the MCP-1 level decreased significantly, compared to the group that received sIL-6R alone; the number of viable bacteria also tended to increase as a result of the inhibition of IL-6 signaling. The cellular phosphotyrosine level in alpha-toxin-treated macrophages was reduced in cultures supplemented with recombinant IL-6 in vitro. These results suggest that IL-6 enhances bactericidal activity and reduces the number of immune cells that are activated abnormally through the regulation of inflammatory cytokines during the early stage of infection in alpha-toxin producers.

Soluble IL-6 receptor governs IL-6 activity in experimental arthritis: blockade of arthritis severity by soluble glycoprotein 130.

Studies in IL-6-deficient (IL-6(-/-)) mice highlight that IL-6 contributes to arthritis progression. However, the molecular mechanism controlling its activity in vivo remains unclear. Using an experimental arthritis model in IL-6(-/-) mice, we have established a critical role for the soluble IL-6R in joint inflammation. Although intra-articular administration of IL-6 itself was insufficient to reconstitute arthritis within these mice, a soluble IL-6R-IL-6 fusion protein (HYPER-IL-6) restored disease activity. Histopathological assessment of joint sections demonstrated that HYPER-IL-6 increased arthritis severity and controlled intrasynovial mononuclear leukocyte recruitment through the CC-chemokine CCL2. Activation of synovial fibroblasts by soluble IL-6R and IL-6 emphasized that these cells may represent the source of CCL2 in vivo. Specific blockade of soluble IL-6R signaling in wild-type mice using soluble gp130 ameliorated disease. Consequently, soluble IL-6R-mediated signaling represents a promising therapeutic target for the treatment of rheumatoid arthritis.

Neuroprotective effects of interleukin-6 on NMDA-induced rat retinal damage.

This study shows that interleukin-6 (IL-6) combined with soluble interleukin-6 receptors (sIL-6R) modulates N-methyl-D-aspartate (NMDA)-induced retinal damage. Eyes pretreated with a combined injection of IL-6 and sIL-6R had NMDA administered into the vitreous cavity. Morphometric analysis and retrograde labeling analysis found that pretreatment with either IL-6 or sIL-6R alone did not bring about any neuroprotective effect. However, pretreatment with a combined administration of IL-6 and sIL-6R induced a significant neuroprotective effect against NMDA-induced retinal damage. Apoptotic changes in the retina were assessed by the TUNEL method. The results indicated that pretreatment with IL-6 combined with sIL-6R prevents NMDA-induced apoptosis. Western blotting studies demonstrated upregulation of gp130 expression in the NMDA-injected retina. Present studies suggest that IL-6 combined with sIL-6R provides a neuroprotective effect on NMDA-induced retinal damage.

Delivery of hyper-interleukin-6 to the injured spinal cord increases neutrophil and macrophage infiltration and inhibits axonal growth.

Cytokine growth factors of the interleukin (IL)-6 family have recently been shown to play an important role in central nervous system (CNS) development, repair, and inflammation. These cytokines, which interact via specific membrane receptors, share a signal-transducing receptor subunit, glycoprotein 130 (gp130). Gp130 is expressed by motoneurons in the gray matter of the rat spinal cord and by several brainstem nuclei that project to the spinal cord including the red, reticular, and vestibular nuclei. In this study, we examined whether stimulation of gp130 signaling, with the use of grafts of fibroblasts genetically modified to deliver the fusion protein, hyper-IL-6 (H-IL-6), which consists of the cytokine growth factor, IL-6, and its alpha receptor, would elicit growth of injured spinal cord axons. Particular emphasis was placed on examining the potentially competing effects of growth factor versus proinflammatory influences of H-IL-6 in the context of spinal cord injury. Our results demonstrated that grafts delivering H-IL-6 induce a sixfold increase in the number of neutrophils (P < 0.05) and a twofold increase in the areas of spinal tissue occupied by macrophages and activated microglia (P < 0.01) at the site of the spinal cord injury when compared with control grafts. Of note, this augmentation in inflammatory cell infiltration correlated with a significant twofold increase in lesion size (P < 0.05) and a fourfold reduction in axonal growth (P < 0.01) at the lesion site. Thus, potential neurotrophic properties of this cytokine family of growth factors must be balanced against their inflammatory properties when considering therapeutic application to CNS injury.

Human myeloma cells promote the recruitment of osteoblast precursors: mediation by interleukin-6 and soluble interleukin-6 receptor.

Multiple myeloma is associated with the development of osteolytic bone disease characterized by a disruption to normal bone resorption and bone formation. Although studies have shown that myeloma cells produce factors that promote bone resorption little data are available examining the mechanism of decreased bone formation or the factors that mediate this effect. In the present study we describe a novel in vitro coculture system in which to investigate the effect of myeloma cells on osteoblast recruitment and differentiation. Under appropriate conditions mesenchymal stem cells were shown to differentiate into colonies of cells, a proportion of which show characteristics of osteoblasts, in that they express alkaline phosphatase activity and stain positively for collagen and calcium. The addition of the human myeloma cells JJN-3, RPMI-8226, or NCI-H929 to these cultures stimulated a significant increase in the total number of colonies (p < 0.005) and the proportion of osteoblastic colonies (p < 0.005). Media conditioned by these cells also were able to promote the formation of both total and osteoblastic colonies (p < 0.005). The addition of an antibody against the interleukin-6 receptor (IL-6R) blocked myeloma cell and myeloma cell-conditioned media induced osteoblast recruitment (p < 0.01). Furthermore, media conditioned by myeloma cells incubated with phorbol ester, which promotes IL-6R shedding, or a metalloproteinase inhibitor, which inhibits IL-6R shedding, were able to stimulate (p < 0.005) and inhibit osteoblast recruitment (p < 0.005), respectively. In addition, soluble IL-6R (sIL-6R) and IL-6 together, but not alone, were able to promote osteoblastic colony formation (p < 0.01). Taken together these data show that myeloma cells promote osteoblast recruitment by release of sIL-6R from myeloma cells.