Unrelated hematopoietic stem cell transplantation for Cernunnos-XLF deficiency

Abstract:  Cernunnos-XLF deficiency is a rare CI characterized by a defective DNA DSB repair mechanism. Its clinical manifestations are growth retardation, dysmorphic features, malformations, and severe B- and T-cell lymphopenia. BM failure may complicate the clinical picture. To date, there have been no described patients with CSy undergoing allogeneic HSCT. We report a case of CSy treated successfully with unrelated allogeneic HSCT after a reduced-intensity conditioning regimen. Two yr after HSCT, the patient maintains full donor engraftment, normal hematopoiesis, and progressively improving immune competence, thus suggesting that HSCT may be the treatment of choice for CSy.     

Cardiac stem cells delivered intravascularly traverse the vessel barrier, regenerate infarcted myocardium, and improve cardiac function

The ability of cardiac stem cells (CSCs) to promote myocardial repair under clinically relevant conditions (i.e., when delivered intravascularly after reperfusion) is unknown. Thus, rats were subjected to a 90-min coronary occlusion; at 4 h after reperfusion, CSCs were delivered to the coronary arteries via a catheter positioned into the aortic root. Echocardiographic analysis showed that injection of CSCs attenuated the increase in left ventricular (LV) end-diastolic dimensions and impairment in LV systolic performance at 5 weeks after myocardial infarction. Pathologic analysis showed that treated hearts exhibited a smaller increase in LV chamber diameter and volume and a higher wall thickness-to-chamber radius ratio and LV mass-to-chamber volume ratio. CSCs induced myocardial regeneration, decreasing infarct size by 29%. A diploid DNA content and only two chromosomes 12 were found in new cardiomyocytes, indicating that cell fusion did not contribute to tissue reconstitution. In conclusion, intravascular injection of CSCs after reperfusion limits infarct size, attenuates LV remodeling, and ameliorates LV function. This study demonstrates that CSCs are effective when delivered in a clinically relevant manner, a clear prerequisite for clinical translation, and that these beneficial effects are independent of cell fusion. The results establish CSCs as candidates for cardiac regeneration and support an approach in which the heart's own stem cells could be collected, expanded, and stored for subsequent therapeutic repair.