Albumin-binding recombinant human IL-18BP ameliorates macrophage activation syndrome and atopic dermatitis via direct IL-18 inactivation

Given the clinical success of cytokine blockade in managing diverse inflammatory human conditions, this approach could be exploited for numerous refractory or uncontrolled inflammatory conditions by identifying novel targets for functional blockade. Interleukin (IL)-18, a pro-inflammatory cytokine, is relatively underestimated as a therapeutic target, despite accumulated evidence indicating the unique roles of IL-18 in acute and chronic inflammatory conditions, such as macrophage activation syndrome. Herein, we designed a new form of IL-18 blockade, i.e., APB-R3, a long-acting recombinant human IL-18BP linked to human albumin-binding Fab fragment, SL335, for extending half-life. We then explored the pharmacokinetics and pharmacodynamics of APB-R3. In addition to an extended serum half-life, APB-R3 alleviates liver inflammation and splenomegaly in a model of the macrophage activation syndrome induced in IL-18BP knockout mice. Moreover, APB-R3 substantially controlled skin inflammation in a model of atopic dermatitis. Thus, we report APB-R3 as a new potent IL-18 blocking agent that could be applied to treat IL-18-mediated inflammatory diseases.

Differences and similarities in cytokine profiles of macrophage activation syndrome in systemic lupus erythematosus and adult-onset Still's disease

To clarify the differences and similarities in the cytokine profiles of macrophage activating syndrome (MAS) between systemic lupus erythematosus (SLE) and adult-onset Still's disease (AOSD). The study participants included 9 patients with MAS-SLE, 22 with non-MAS-SLE, 9 with MAS-AOSD, and 13 with non-MAS-AOSD. Serum cytokine levels were measured using a multiplex bead assay. Cytokine levels were compared between patients with SLE and AOSD with/without MAS. Moreover, cytokine patterns were examined using principal component analysis (PCA) and cluster analysis. IL-6, IL-8, IL-18, and TNF-α levels were elevated in patients with SLE and AOSD. IFN-α levels were elevated in SLE, whereas IL-1β and IL-18 levels were elevated in AOSD. In SLE, IFN-α and IL-10 levels were higher in MAS than in non-MAS and controls. PCA revealed distinctive cytokine patterns in SLE and AOSD, SLE with IFN-α and IP-10, AOSD with IL-1β, IL-6, and IL-18, and enhanced cytokine production in MAS. PCA and cluster analysis showed no differences in cytokine patterns between the MAS and non-MAS groups. However, serum ferritin levels were correlated with IFN-α levels in SLE. Cytokine profiles differed between SLE and AOSD but not between MAS and non-MAS. MAS is induced by the enhancement of underlying cytokine abnormalities rather than by MAS-specific cytokine profiles. Type I IFN may be involved in MAS development in patients with SLE.

Adult-onset Still's disease-like manifestation accompanied by the cancer recurrence after long-term resting state

A 72-year-old woman presented 9 months ago with skin rash on her bilateral forearms, which was followed by intermittent high fever, and stiffness and swelling of her bilateral fingers. She was diagnosed with seronegative rheumatoid arthritis (RA). She had a past history of breast cancer and had undergone breast preservation surgery 13 years previously. During admission in our hospital, she developed high fever and leukocytosis with a relapsing skin rash, sore throat, polyarthralgia and increased levels of serum ALT/AST and ferritin, all of which fulfilled Yamaguchi's criteria for adult-onset Still's disease (AOSD). While we tried to exclude other diseases that may show AOSD-like manifestations, pancytopenia rapidly developed and bone marrow biopsy strongly suggested the diagnosis of macrophage activating syndrome (MAS). Accordingly, steroid pulse therapy was begun, followed by oral glucocorticoid therapy. Thereafter, all of her symptoms improved, but systemic rash, inflammatory signs and pancytopenia gradually progressed. The results of bone marrow pathology, which returned 2 weeks after the beginning of treatment, revealed hemophagocytosis with CK7-positive/CK20-negative atypical cells that suggested recurrence of breast cancer in the bone marrow, thus all of her AOSD-like symptoms were considered to be paraneoplastic manifestations of late-onset metastatic breast cancer. She was treated successfully with chemotherapy. When we see the patients showing AOSD-like symptoms with a history of malignancy, we should consider the possibility of paraneoplastic syndrome due to cancer recurrence.

Association of Macrophage Activating Syndrome with Castleman's Syndrome in Systemic Lupus Erythematosus

Macrophage Activating Syndrome (MAS) is a life-threatening disease seen in autoimmune diseases including lupus erythematosus, rheumatoid arthritis, Still's disease, polyarteritis nodosa. It is characterized by fever, pancytopenia, liver failure, coagulopathy, and neurologic symptoms and high serum ferritin. A 27 yr. old female patient was admitted in shahid Mostafa Khomeini Hospital (Tehran-Iran) in May 2011 because of lower extremities edema and ascites and fever from 1.5 month ago. In physical examinations she had generalized lymphadenopathy, splenomegaly and pleural effusion. In laboratory tests she had pancytopenia, positive ANA and Anti DNA (ds), hypocomplementemia, hypertriglyceridemia and high ferritin level. Gradually she had signs of RPGN and ARDS. The patient had no skin and musculoskeletal signs of SLE and no liver failure nor coagulopathy of MAS. Her lymph node biopsy was reported as Castleman syndrome. Unlike other studies, the patient showed MAS before treatment with cytotoxic for lupus nephritis.