Current Concepts in Rheumatology,Royal Society of Medicine

Ustekinumab is a fully human monoclonal antibody directed against the p40 subunit shared by interleukin 12 and interleukin 23, two naturally occurring protein regulators that play an important role in immune-mediated inflammatory diseases, including psoriatic arthritis (PsA). In September of 2009, the US FDA approved ustekinumab for the treatment of adult patients with moderate to severe plaque psoriasis. Beginning in November of 2009, Janssen Biotech (formerly Centocor Biotech), the developer of ustekinumab, initiated clinical trials to investigate the efficacy of ustekinumab in the treatment of other inflammatory disorders, including PsA. Phase II and Phase III studies showed both a good safety profile and significant efficacy for ustekinumab in the treatment of PsA, leading to the drug's approval in both Europe and the USA. In an immunotherapy market currently dominated by anti-TNF-α drugs for the treatment of PsA, ustekinumab offers an alternative option for patients with PsA, including those unresponsive to methotrexate and the TNF-α inhibitory agents currently approved for this potentially debilitating disease.     

Clinical significance of variations in levels of Epstein-Barr Virus (EBV) antigen and adaptive immune response during chronic active EBV infection in children

Abstract

Pediatric patients were recruited to analyze differences in Epstein-Barr virus (EBV) copy numbers and adaptive immune reactions in children with chronic active vs acute EBV infection (CAEBVI vs AEBVI), as well as to examine the relationship between these parameters and the pathogenesis of CAEBVI. Fluorescent qPCR was used to assess EBV-DNA levels, while ELISA, antibody affinity, flow cytometry, and heterophil agglutination (HA) assays were used to evaluate patient EBV-adaptive humoral and cellular immunity. Lastly, ELISPOT was employed to assess interferon (IFN)-γ secretory functions of EBV-specific cytotoxic T-lymphocytes (CTL) as a marker of subject EBV-specific adaptive cellular immunity. The results indicated that, compared with AEBVI patients or normal children, there was a dramatic elevation in viral copy levels, viral capsid antigen (VCA)-IgA, early antigen (EA)-IgA, and EA-IgG, but a lack of EBV nuclear antigen (EBNA)-IgG and a negative HA in CAEBVI patients (p?<?0.01). These subjects also had decreased CD4⁺, CD8⁺ (naïve), CD8⁺CD38⁺, and effective memory T-lymphocyte levels compared with AEBVI patients (p?<?0.01), and decreased EBV-specific CTL function compared with normal children (p?<?0.01). These results suggest that there is a disturbance in EBV antigen availability and in both the adaptive humoral and cellular immune responses in patients with CAEBVI, and that these outcomes may be associated with the chronic active re-infection process itself associated with CAEBVI.     

Autoantibody production in patients treated with anti-TNF-α

Patients with rheumatoid arthritis, Crohn’s disease or spondyloarthritis who are treated with selective TNF-α inhibitors may develop autoantibodies, such as antinuclear antibodies (ANAs) and anti-dsDNA antibodies. Various methods have shown that infliximab led to ANAs in 29–76.7% and anti-dsDNA antibodies in 10–29% of rheumatoid arthritis patients participating in clinical trials. Furthermore, ANAs and anti-dsDNA antibodies have appeared in 11–36 and 5–15% of rheumatoid arthritis patients treated with etanercept and 12.9% and 5.3% of those treated with adalimumab, respectively. Antiphospholipid antibodies, which are mainly detected by means of anticardiolipin assays, have also been found in rheumatoid arthritis patients receiving TNF-α blockers. There have been a number of reports of the development of antidrug antibodies, of which those against infliximab lead to infusion reactions and shorter responses to treatment. This has led some authors to conclude that it is necessary to add methotrexate to infliximab in order to reduce the risk of the appearance of anti-idiotype autoantibodies     

PD-1 blockade: promoting endogenous anti-tumor immunity

The co-inhibitory receptor programmed death-1 acts to dampen immune responses in peripheral tissues via interaction with its widely distributed ligand(s). The latter function as a final ‘shield’ to protect tissues from immunological attack by T cells and help to maintain peripheral tolerance and prevent autoimmunity. Upregulation in a variety of cancers is thought to be one mechanism by which they evade immunological eradication. The study by Topalian and colleagues evaluating the role of blockade of this pathway with a monoclonal antibody in patients with advanced cancer is reviewed. This large Phase I study demonstrates encouraging response rates in patients with melanoma, renal cell carcinoma and non-small-cell lung cancer. Although the spectrum of toxicity was similar to that seen with blockade of cytotoxic T-lymphocyte antigen 4, the severity appeared lower in most cases. After a long wait, it finally seems that immune-based anticancer therapies are emerging to become part of the mainstream.     

Nivolumab and pembrolizumab as immune-modulating monoclonal antibodies targeting the PD-1 receptor to treat melanoma

Malignant melanoma is an important issue in oncology due to its high incidence, high mortality, and resistance to systemic therapy; however, targeted immunotherapy has noticeably improved the survival rates of melanoma patients. Promising targeted immunotherapies for malignant melanoma include the blockade of immune checkpoints with antibodies targeting cytotoxic T lymphocyte-associated antigen 4 and the programmed cell death protein 1 pathway. The US FDA-approved antibody ipilimumab targets cytotoxic T lymphocyte-associated antigen 4; however, it was limited by toxicity and a low response. Nivolumab and pembrolizumab (formerly lambrolizumab), the two FDA-approved anti-programmed death-1 monoclonal antibodies, show highly durable response rates and long-term safety, validating the importance of the programmed cell death protein 1 pathway blockade for treatment of malignant melanoma.