Neurotrophic Bone Marrow Cellular Nests Prevent Spinal Motoneuron Degeneration in Amyotrophic Lateral Sclerosis Patients

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, characterised by loss of motoneurons (mns), and it has no cure. Cell therapy has neurotrophic effects in animal models and has been proposed as a disease-modifying treatment. Our aim was twofold: firstly, to assess the safety of intraspinal infusion of bone marrow mononuclear cells (BMNC) and, ultimately, to look for histopathological signs of cellular neurotrophism.

We conducted an open single arm phase I trial. After six months observation, autologous BMNC were infused into the posterior spinal cord funiculus. Safety was the primary endpoint and was defined as the absence of serious transplant-related adverse events. In addition, forced vital capacity (FVC) and ALS-FRS, MRC and Norris scales were assessed six and three months prior to the transplant and quarterly afterwards for one year. Pathological studies were performed in case of death.

Eleven patients were included. We did not observe any severe transplant-related adverse event but there were 43 non-severe events. Twenty-two (51%) resolved in ≤2 weeks and only four were still present at the end of follow-up. All were CTCAE grade ≤2. No acceleration in the rate of decline of FVC, ALS-FRS, Norris or MRC scales was observed. Four patients died on days 359, 378, 808 and 1058 postransplant for reasons unrelated to the procedure. Spinal cord pathological analysis showed a greater number of montoneurons in the treated compared to the untreated segments (4.2+/−0.8 mns/section and 0.9+/−0.3 mns/section, respectively). In the treated segments, motoneurons were surrounded by CD90+ cells and did not show degenerative ubiquitin deposits.

This clinical trial confirms not only the safety of intraspinal infusion of autologous BMNC in ALS patients but also provides evidence of their neurotrophic activity.

No relevant conflicts of interest to declare.