While arachidonic acid (AA), which is classified into n-6 polyunsaturated fatty acid (PUFA), has been mainly recognized as a substrate of pro-inflammatory mediators, eicosapentaenoic acid or docosahexaenoic acid, which are classified into n-3 PUFA, is currently identified as substrates of mediators inducing resolution of inflammation, namely pro-resolving mediators (SPM). As with any other pathological conditions, it is gradually elucidated that SPMs contributes a certain effect on joint inflammation. In osteoarthritis (OA), Lipid fractions extracted from adipocytes, especially in infrapatellar fat pad rather than subcutaneous tissue induce T cell skewing for producing IFN-γ or decrease the production of IL-12p40 from macrophages. In synovial tissues form OA, there are some of known receptors for SPM. In the synovial fluid from rheumatoid arthritis (RA), it could be identified and quantified a certain kind of SPMs such as maresin 1, lipoxin A4 and resolvin D5. In murine models of arthritis, some of SPMs are found to have some functions to reduce tissue damage. Correctively, SPMs might have some potential to a novel therapeutic target for arthritis or any other rheumatic diseases.
The dramatic and long durable anti-tumor effect of immune checkpoint blockade, such as anti-CTLA-4 Ab, anti-PD-1 Ab, and anti-PD-L1 Ab was surprised the world. In addition, CAR-T cell therapy that target the CD19 indicates a very high response rate to the CD19-positive hematologic malignancies. Now, no one doubts the presence of immunity against cancer. Further, accordingly, tumor-specific neoantigen are attention now, the clinical trials of individualized peptide vaccination that target patient individual neoantigens has begun in the Western. On the other hand, the peptide vaccine therapy that target common self-antigen is not yet been approved in Japan, the development is struggling. In this paper, I overview the cancer immunotherapy and neoantigen and introduce some development of cancer immunotherapy in Japan.
Chemokines induce migration of inflammatory cells. In the synovial tissue of rheumatoid arthritis (RA), abundant chemokines are expressed, which contribute migration of lymphocytes and monocytes/macrophages, stimulation of synovial cells, and angiogenesis. Blockade of CCL2, CCL3, CCL5, CCR1, CCR9, CXCL2, CXCL5, CXCL13, CXCL16, CXCR3, CXCR4, CXCR7, and CX3CL1 showed improvement of arthritis of animal models. Moreover, CCR1 antagonist and anti-CXCL10 antibody reduced arthritis of patients with RA. Chemokine is a promising target for RA therapy.
Biologics have revolutionized the treatment of rheumatoid arthritis (RA). However certain amount of the patients cannot achieve goal of therapy. Recently, compounds targeting the intracellular kinase, Janus kinase (JAK) have demonstrated therapeutic effects resembling biologics. Tofacitinib is the only JAK inhibitor approved for RA and during the clinical trial, increased events of herpes zoster (HZ) was observed. Incidence rate was twice as much as patients treated with conventional anti-rheumatic drug and was especially increased in Japan that was four times as much. The risk factors were age and glucocorticoid that is identical to that of common RA patients and there was nothing specific for tofacitinib. Mechanism of increased incidence of HZ and the difference in ethnicity remains unknown. Analysis of clinical trials have identified that HZ do not correlate with further adverse events. Therefore, it is extremely important to accumulate clinical data with considerable amount of patients with long term follow up including the post marketing surveillance in Japan to reveal the significance of increased HZ in RA patients.
Liposteroid, a lipid emulsion containing dexamethasone, was developed in Japan. This drug is effective against rheumatoid arthritis, and has fewer side effects than dexamethasone. Moreover, at high dosage, liposteroid has been effectively used for the treatment of macrophage activation syndrome, because the lipid emulsions are easily taken up by phagocytes, and are retained in macrophages. Its anti-inflammatory effect was found to be 2-5 times higher than that of dexamethasone in arthritis and granuloma rat models. Japanese researchers have reported the clinical efficacy and utility of liposteroid in the treatment of diseases with macrophage activation. These include hemophagocytic lymphohistiocytosis, graft-versus-host disease, and pulmonary hemosiderosis. Here, we describe the clinical effects of liposteroid on macrophage activation syndrome and the hypothalamus-pituitary-adrenal axis in patients.
One of the major roles of B cells is to generate antibodies to specific antigens. Secreted antibodies are the principal molecules involved in humoral immunity, with the capacity not only to neutralize pathogens, but also to enhance their elimination by activating phagocytosis or complement proteins. Recently, it has been highlighted that B cells exert important regulatory roles independent of their antibody producing function. These roles include efficiently presenting antigens to the T cells, secreting cytokines, and inducing immune cell differentiation. Thus, B cells have emerged as cells that play crucial roles in immune systems in addition to producing antibodies. Systemic sclerosis (SSc) is characterized by autoimmunity and tissue fibrosis of several organs. Although the pathogenic relationship between systemic autoimmunity and the clinical manifestations of SSc remains unknown, SSc patients display a variety of abnormal immune activation including the production of disease-specific autoantibodies. Previous studies have demonstrated that immune cells, mainly including B cells, play a critical role in systemic autoimmunity and disease expression, though the role of autoimmunity in generating the clinical and pathologic phenotype in SSc remains uncertain. SSc patients have B cell abnormalities characterized by chronic hyper-reactivity of memory B cells. Although distinct subsets of autoantibodies do not have a proven pathogenic role, they are selectively associated with unique disease manifestations. To date, the treatment of SSc has largely relied on cytotoxic immunosuppressants and corticosteroids. Although this has resulted in improved disease survival, these patients may still suffer severe adverse events and refractory disease to conventional immunosuppressive therapies. Recently, clinical trials involving the chimeric monoclonal antibody rituximab have raised high expectations. B cell depleting therapy with rituximab offers a promising treatment for the rheumatic autoimmune diseases including SSc. This article reviews the current knowledge of B cell biology and pathogenesis in SSc as well as the therapeutic approaches focusing on the targeting of B cell specific surface molecules and on the blocking of B cell activation and survival.
A small percentage of those infected with human T-lymphotropic virus type 1 (HTLV-1) develop HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a debilitating neurodegenerative disease. This disease impacts essential bodily functions, and since currently available treatments are considered to be poorly effective, there is a dire need to develop a truly effective treatment to suppress disease progression. Recently, the authors and others have determined that HTLV-1 in HAM/TSP patients primarily infects T cells expressing the chemokine receptor CCR4. The authors postulated that HTLV-1 causes these T cells to develop Th1-like functions that are critical for the pathogenesis of HAM/TSP. They described an inflammatory positive feedback loop in which cross-talk between these abnormal Th1-like cells and astrocytes produce and maintain spinal cord lesions in HAM/TSP patients. When an anti-CCR4 antibody was tested against cells from HAM/TSP patients, the antibody instigated the destruction of the CCR4-positive cells, reducing the number of infected cells and the amount of inflammatory activity. Thus, the anti-CCR4 antibody is expected to become a fundamentally new treatment for HAM/TSP that directly targets infected cells. The treatment is currently being tested in clinical trials.
Trimethoprim-sulfamethoxazole (TMP/SMX) treatment for pneumocystis pneumonia (PCP) in patients with autoimmune diseases who developed PCP was conducted in a retrospective study of the following: dosage, frequency of side effects and persistence rate of TMP/SMX and prognosis of patients. Seven patients (two males and five females, mean age: 72 years) were hospitalized between April 1, 2013 and August 31, 2015, and their underlying diseases were rheumatoid arthritis (six patients) and microscopic polyangiitis (one patient). Moderate-dose TMP/SMX (TMP equivalent to TMP/SMX, average: 9.6 mg/kg/day, range: 5.1-12.5 mg/kg/day) was used for PCP treatment. As a result, patients experienced the following side effects: hyponatremia in five patients (71.4%), exanthema in four patients (57.1%), and thrombocytopenia in two patients (28.6%). Elevated creatinine level, increased blood pressure, malaise, and hyperkalemia were experienced by each patient. Six patients (85.7%) discontinued TMP/SMX treatment due to side effects, but once they had recovered, desensitization to TMP/SMX was used to treat them. Eventually, four patients were successfully treated with TMP/SMX (final persistence rate, 57.1%). Their prognoses were good, and no patients died for at least 60 days after admission. Moderate-dose TMP/SMX treatment for PCP in patients with autoimmune diseases who developed PCP may have therapeutic effects equal to high-dose TMP/SMX treatment, and therefore collecting more case studies is expected.
We report a 36-year-old male patient who suffered from polyarthritis after the remission of ulcerative colitis. He was diagnosed with enteropathic arthritis type 2, against which methotrexate was effective.