佐藤 健夫

AIM: This study aimed to evaluate the predictive value of serum humoral factors in determining the therapeutic responses to biologic DMARDs (bDMARDs), especially TNF inhibitors (TNFis), in patients with RA. METHODS: A cohort of 52 patients with RA who were treated with bDMARDs, including TNFis, abatacept, and tocilizumab, was analyzed. Serum samples were collected at baseline (t1), 5 ± 1 (t2), and 14 ± 2 weeks (t3) after treatment. A bead-based immunoassay was used to quantify serum cytokines/chemokines. Treatment response was determined 1 year after initiation. RESULTS: Distinct patterns of IL-6 behaviors were observed among different bDMARDs. Patients exhibiting IL-6 rebound at 14 weeks were more likely to be non-responders to TNFi after 1 year, and this rebound appeared to be associated with increases in IFN-γ and IL-12 levels. IFN-β was more detectable than IFN-α2 in RA. Additionally, patients with measurable IFN-β at baseline tended to be TNFi responders. CONCLUSION: Monitoring serum humoral factors may offer valuable insights into the likelihood of therapeutic success of TNFi in patients with RA. IL-6 rebound at 14 weeks might serve as an early indicator of non-responsiveness to TNFi. These findings highlight the potential of personalized treatment strategies for RA based on serum humoral factor profiling. Larger prospective studies are needed to validate these results and elucidate the underlying mechanisms.

A 53-year-old woman with a 6-year history of rheumatoid arthritis (RA) presented with pharyngeal pain, fever, and altered mental status. The patient had been treated with methotrexate (MTX) 12 mg/week, baricitinib 4 mg/day, and tacrolimus 2 mg/day. Magnetic resonance imaging of the brain revealed diffuse high-intensity lesions in the cerebral white matter, basal ganglia, brainstem, and right cerebellar hemisphere. She was diagnosed with Epstein-Barr virus (EBV) encephalitis due to elevated levels of EBV-DNA in the cerebrospinal fluid and serum. Although MTX-associated lymphoproliferative disorders are well-known complications in patients with RA, EBV encephalitis requires careful attention for such patients undergoing treatment with multiple potent immunosuppressants.

AIM: The use of an immunosuppressant is recommended as a treatment for remission induction in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). However, the immunosuppressant is sometimes discontinued due to an adverse event. We sought to identify the cause and risk factors for immunosuppressant discontinuation in patients with AAV receiving remission induction treatment. METHODS: We retrospectively analyzed the cases of AAV patients treated in 2005-2016 with immunosuppressants to induce remission. We defined "discontinuation" as stopping, switching, or delaying immunosuppressant administration due to adverse events. We performed a multivariate analysis to identify risk factors for immunosuppressant discontinuation. RESULTS: We identified 50 patients treated with an immunosuppressant for remission induction: cyclophosphamide was used in 45 patients (90%), methotrexate in 4 (8%), and cyclosporine A in 1 patient (2%). Among them, 26 patients (52%) underwent discontinuation of the immunosuppressant. Infection and myelosuppression were the major causes of discontinuation. Multivariate Cox proportional hazards regression analysis revealed that a cumulative dose of prednisolone ≥ 2000 mg (hazard ratio [HR] =2.18, 95% confidence interval [CI] =1.37-3.70, P < .001), performance status of 3-4 (HR = 1.80, 95% CI = 1.07-3.03, P = .027), and oral cyclophosphamide (HR = 1.81, 95% CI = 1.11-2.97, P = .018) were independent risk factors correlated with immunosuppressant discontinuation. CONCLUSION: Physicians should be aware of risk factors predicting immunosuppressant discontinuation when treating AAV patients with an immunosuppressant.