We thank Dr. Finlay-Morreale for comments about our publication entitled “Outcomes of bone marrow mononuclear cell transplantation combined with interventional education for autism spectrum disorder.”^{1, 2} Please rest assured that we appreciate any constructive criticism, and we take any concerns expressed very seriously. We would like to clarify some of the issues stated in the letter.

As we all know, the incidence and prevalence of autism seems to be increasing worldwide.³ So far, educational intervention is still considered the standard treatment for children with autism, but unfortunately, there are still many children who do not respond well to this method.^{4, 5} That is why other treatments—including stem cell infusions—are being studied.

With regard to your question concerning the cell transplants, we infused mononuclear cells from bone marrow containing hematopoietic stem cells and progenitor cells. Although mechanisms of action remain to be studied, their ability to secrete bioactive molecules and to migrate rapidly to inflammation sites has attracted great interest in their use for autism.^6-9 In addition, bone marrow mononuclear cells contain precursors of mesenchymal stem/stromal cells, and human muse cells (nontumorigenic pluripotent-like stem cells).^10-12 We specified the number of mononuclear cells, CD34⁺ hematopoietic stem cells, and progenitor cells in the section “BMMNC transplantation”: “The average mononuclear cell and CD34⁺ cell counts per kg body weight were 42.3 × 10⁶/kg and 2.6 × 10⁶ for the first transplantation and 40.9 × 10⁶/kg and 2.1 × 10⁶ for the second transplantation, respectively.”

The second concern expressed in the letter was the safety of intrathecal injection. It is well established that lumbar puncture and intrathecal infusion are standard procedures in modern medicine. This approach has been commonly used for pain relief during or after operations.^13-16 In children, this route is also used in the treatment of cerebral palsy with the administration of Baclofen or in the context of stem cell infusions.^17-22 Reports have shown that this is a safe procedure, without serious complications, and with low incidence of minor accidents. In our study, 26 minor adverse events (AEs) related to the intervention, which occurred during the first week of infusion, included pain, broken vein, peripheral vein masonry, and slipping needle out of the vein during infusions. The 17 AEs including mild fever, nausea, and vomiting occurred during the 18-month follow-up period.

Stem cell infusion through the intrathecal route for autism has been used by some authors before us. Reports have also shown this route to be safe, with low incidence of side effects.^{23, 24}

We understand that intravenous stem cell transfusion would be less invasive than intrathecal. However, studies have shown that the majority of stem cells could not reach the brain because most have been trapped in the lungs and spleen,²⁵ a problem often described as first-pass effect, rendering the infusions largely ineffective.

All patients in our study underwent educational intervention before the mononuclear cell infusion with an average duration of 34 ± 17.5 months. However, improvements were marginal and CARS scores still placed them in the “severe” category of autism. Postinfusion monitoring revealed increased progress that was tracked over time, specifically over the course of 18 months in total, exhibiting sustainable results during and throughout that follow-up period.

Limitations in our study, such as no control group, were indeed highlighted in our article, and we also recommended that a future study including a control group is required to accurately conclude the benefit of stem cells in improving autism disorders. Furthermore, we have always believed that even given the potential of stem cell infusions, a combination with educational intervention is still very important to help achieve significant changes in the quality of life of children with autism.

In conclusion, our study demonstrated that repeated bone marrow mononuclear cell infusion via intrathecal route is safe and provides initial evidence for a significant improvement in clinical outcomes for children suffering from autism spectrum disorder, justifying a future randomized, fully controlled clinical trial.

我们感谢 Finlay-Morreale 博士对我们题为“骨髓单核细胞移植与自闭症谱系障碍介入教育相结合的结果”的出版物的评论。^{1, 2}请放心，我们感谢任何建设性的批评，并且我们非常认真地对待所表达的任何关切。我们想澄清信中提出的一些问题。

众所周知，自闭症的发病率和患病率似乎在全球范围内不断增加。³迄今为止，教育干预仍然被认为是自闭症儿童的标准治疗方法，但不幸的是，仍然有很多儿童对这种方法反应不佳。^{4, 5}这就是为什么正在研究其他治疗方法（包括干细胞输注）的原因。

关于你关于细胞移植的问题，我们输注了来自骨髓的含有造血干细胞和祖细胞的单核细胞。尽管作用机制仍有待研究，但它们分泌生物活性分子和快速迁移到炎症部位的能力引起了人们对其用于治疗自闭症的极大兴趣。^6-9此外，骨髓单核细胞含有间充质干细胞/基质细胞和人 muse 细胞（非致瘤性多能样干细胞）的前体。^{10-12我们在“BMMNC移植”部分具体规定了单核细胞、CD34 +}造血干细胞和祖细胞的数量：“每公斤体重平均单核细胞和CD34 ^{+细胞计数为42.3×10 6} /kg，第一次移植为2.6×10 ⁶ ，第二次移植分别为40.9×10 ⁶ /kg和2.1×10 ^{6 。}

信中表达的第二个担忧是鞘内注射的安全性。众所周知，腰椎穿刺和鞘内输注是现代医学的标准程序。这种方法通常用于缓解手术期间或手术后的疼痛。^13-16在儿童中，该途径还用于通过给予巴氯芬或干细胞输注来治疗脑瘫。^17-22报告显示，这是一种安全的手术，没有严重的并发症，小事故的发生率也很低。在我们的研究中，输注第一周内发生了 26 起与干预相关的轻微不良事件 (AE)，包括疼痛、静脉破裂、外周静脉砌筑以及输注期间针头从静脉滑出。17 项 AE 包括轻度发烧、恶心和呕吐，发生在 18 个月的随访期间。

在我们之前的一些作者已经使用通过鞘内途径输注干细胞来治疗自闭症。报告还表明这种途径是安全的，副作用发生率低。^{23, 24}

我们知道静脉干细胞输注比鞘内输注的侵入性更小。然而，研究表明，大多数干细胞无法到达大脑，因为大多数干细胞被困在肺和脾中，²⁵这个问题通常被描述为首过效应，导致输注基本上无效。

我们研究中的所有患者在单核细胞输注前均接受了教育干预，平均持续时间为 34 ± 17.5 个月。然而，改善幅度很小，CARS 评分仍然将他们归入“严重”自闭症类别。输注后监测显示，随着时间的推移，特别是在总共 18 个月的过程中，跟踪的进展有所增加，在整个随访期间和整个随访期间表现出可持续的结果。

我们的文章确实强调了我们研究的局限性，例如没有对照组，我们还建议未来需要进行包括对照组在内的研究，以准确得出干细胞在改善自闭症方面的益处。此外，我们始终相信，即使干细胞输注具有潜力，与教育干预相结合对于帮助自闭症儿童的生活质量实现重大改变仍然非常重要。

总之，我们的研究表明，通过鞘内途径重复骨髓单核细胞输注是安全的，并为患有自闭症谱系障碍的儿童的临床结果显着改善提供了初步证据，证明了未来随机、完全对照临床试验的合理性。