Hemophilia arthropathy (HA) represents the majority of morbidity in severe hemophilia patients, especially in resource-limited countries. Adeno-associated virus (AAV)-mediated gene therapy is showing promise for managing hemophilia. However, patients with neutralizing antibodies (NAbs) against AAV, and inhibitors to clotting factors, are excluded from such therapy. This study explored the feasibility of AAV-mediated local gene therapy for HA. Factor VIII knockout (FVIII-/-) mice, with or without a FVIII inhibitor, were subjected to hemarthrosis induction and treated with either intravenous (IV) or intraarticular (IA) recombinant human factor VIII (rhFVIII). To investigate whether rhFVIII carried the risk to develop a FVIII inhibitor, FVIII-/- mice were treated with three doses of IV or IA rhFVIII and inhibitor development was measured. In patients with established HA requiring synovial fluid aspiration, plasma, and synovial fluid were collected and measured for anti-AAV capsid IgG (serotypes 1-9 and 843) and NAbs for AAV843. IA rhFVIII provided better protection from synovitis compared with IV rhFVIII, with or without the FVIII inhibitor. While IV rhFVIII led to all FVIII-/- mice developing an FVIII inhibitor (n = 31, median 4.9 Bethesda units [BU]/mL), only 50% of the mice developed a FVIII inhibitor by IA administration, and at a lower titer (median 0.55 BU/mL). In hemophilia patients, total anti-AAV IgG was lowest for AAV4 and AAV5, both in plasma and synovial fluid. Anti-AAV IgGs in synovial fluid for most samples were lower or similar to the plasma levels. These results show that direct IA rhFVIII administration yields better protection against bleeding-induced joint damage, even in the presence of an inhibitor antibody. IA rhFVIII delivery carried a lower risk of FVIII inhibitor formation compared with IV FVIII. The anti-AAV antibody level in synovial fluid was similar or lower than the plasma level, supporting the feasibility of local gene therapy for managing HA.

中文翻译：

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探索关节内腺相关病毒介导的血友病关节病基因治疗的潜在可行性。

血友病关节病 (HA) 代表了严重血友病患者的大部分发病率，尤其是在资源有限的国家。腺相关病毒 (AAV) 介导的基因治疗显示出治疗血友病的希望。然而，具有针对 AAV 的中和抗体 (NAb) 和凝血因子抑制剂的患者被排除在此类治疗之外。本研究探讨了 AAV 介导的局部基因治疗 HA 的可行性。因子 VIII 敲除 (FVIII-/-) 小鼠，有或没有 FVIII 抑制剂，进行关节积血诱导，并用静脉内 (IV) 或关节内 (IA) 重组人因子 VIII (rhFVIII) 进行治疗。为了研究 rhFVIII 是否具有产生 FVIII 抑制剂的风险，FVIII-/- 小鼠接受了三个剂量的 IV 或 IA rhFVIII 治疗，并测量了抑制剂的发展。在需要滑液抽吸的确诊 HA 患者中，收集血浆和滑液并测量抗 AAV 衣壳 IgG（血清型 1-9 和 843）和 AAV843 的 NAb。与 IV rhFVIII 相比，无论是否使用 FVIII 抑制剂，IA rhFVIII 都能提供更好的滑膜炎保护。虽然 IV rhFVIII 导致所有 FVIII-/- 小鼠产生 FVIII 抑制剂（n = 31，中值 4.9 Bethesda 单位 [BU]/mL），但只有 50% 的小鼠通过 IA 给药产生 FVIII 抑制剂，并且滴度较低（中值 0.55 BU/mL）。在血友病患者中，血浆和滑液中 AAV4 和 AAV5 的总抗 AAV IgG 最低。大多数样本的滑液中的抗 AAV IgG 低于或与血浆水平相似。这些结果表明，即使存在抑制剂抗体，直接 IA rhFVIII 给药也能更好地防止出血引起的关节损伤。与 IV FVIII 相比，IA rhFVIII 递送具有较低的 FVIII 抑制剂形成风险。滑液中的抗 AAV 抗体水平与血浆水平相似或低于血浆水平，支持局部基因治疗管理 HA 的可行性。