Stem Cells Transplantation As A Recent:

Mohammed Abd Al Fattah Shehata Hanafy ;

The development of spinal cord injury treatment is focused on newmethods of regenerative medicine such as the administration of growthfactors, and An emerging strategy for replacing and/or regeneratingdamaged tissue is the implantation of stem cells and/or artificialbiomaterials such as scaffolds to form tissue bridges between damagedspinal cord stumps.The use of autologous (Bone Marrow Cells) BMCs for stem celltherapy in (Spinal Cord Injury) SCI patients has more advantages.First, one can avoid all problems associated with the immunologicalrejection or graft-versus-host reactions, which are frequently caused inallogenic cell transplantation. Second, autologous BMC therapy isconsidered safe by not being associated with carcinogenesis [Beachy etal2004]. Third, extensive scientific data on BMCs have been accumulatedfrom previous experiences in BMC transplantation for hematologicaldiseases. These advantages have made cell therapy using BMCs widelyapplicable and investigated clinicallyin various neurologic diseases.However, it also has some disadvantages. First, the procedurerequires open surgery to approach the injury area in direct method ofdelivery, which results in the increase in the potential adverse effects.Second, the sorting of BMCs needs to be done in vitro, thus increasingthe risk of contamination. Third, it is still unclear whether some BMCcomponents may have a deleterious effect on the functional improvement.Also When bone marrow was aspirated from the iliac bone, andmononuclear cells were sorted and concentrated.Theoretically and clinically, lumbar puncture delivery of stem cellsis extremely attractive. Lumbar puncture is a minimally invasiveprocedure that can be performed at the bedside after injection of a localanesthetic. In humans lumbar puncture is performed at the L3–4 level, faraway from the cervical or thoracic spinal cord, which are the regionsmost commonly effected by SCI. This makes lumbar puncture delivery ofstem cells relatively safe and unlikely to worsen compromised patients asa direct result of the intervention .Additional advantages of lumbar puncture delivery are related toseveral factors:4) The cells are delivered across the blood brain barrier into theCSF, making it far more efficient than intravenous delivery.5) CSF circulates within the CNS, allowing transplanted cellsto home into the injured tissues, and cells are preserved in arelatively immune-privileged environment.6) Because the transplanted cells are delivered away from thehostile environment of the injured tissue, they are given agreater opportunity to survive and migrate to the injury siteIntravenous Route: Least EfficientVery few to no cells were present within the injured spinalsegments in rats that received BMSCs intravenously. In contrast,considerably more cells were detected in the injured tissues after bothintrathecal and intraventricular delivery . These data confirm thehypothesis that transplanting cells into the CSF leads to more successfulgrafting when injection is via an intrathecal or -ventricular rather thanintravenous route. It should be noted that the same cell dosage (2 millioncells) was used for all routes and varying cell dosages might lead toimproved grafting efficacy.The application of bone marrow derived leukocyte suspension,including stem cells is a safe medical procedure with acceptable adversereactions. Improvement in the sensory function occurs in almost all of thepatients.Improvement was recorded even in patients with lumbar infusion ofthe stem cells, suggesting direct effect of stem cell implantation onsensory improvement.Very minor changes in motor function were noted in several of thepatients. Improvement initiated around the 90th day followingimplantation of the stem cells and fully developed after the 8th monthfrom the procedure. Repetition of the stem cell implantation had a lessereffect if any.The most recent study done by Hadjianev in2008 show that93.2% of the patients had improvement in the sensory function .The improvement was noted in patients who had either laminectomy orinterlaminotomyFew of the patients, mostly those with existing motor function(14.8%), had improvement in movements. These improvements wereregistered as an increase of the existing voluntary movements (abduction,adduction, flexion and extension) or new activities in certain musculargroups that were lost after the injury.In some of the patients (9.5%), an absolute increase in the musclemass of the lower extremities (~1-1.5 cm in circumference) wasregistered. Three of the patients who had partial sphincter controlfollowing the accident regained full control after the procedure.(Hadjianev A etal.,2008).ConclusionOf all types of implantation, Direct injection of stem cells gives thebest resultsBMC implantation is promising, as regard, sensory function hasbeen improved, Also it shows some motor function improvement, asregard the post traumatic existing voluntary movement, there is increasein the muscle mass of the lower and regaining full sphincter control inpatients who had partial sphincter control.A further more comprehensive multicenter study is recommendedto establish the therapeutic effect of stem cell implantation.