Jesse D. Vrecenak

In utero hematopoietic cell transplantation—recent progress and the potential for clinical application

In utero hematopoietic stem cell transplantation (IUHCT) is a potential therapeutic alternative to postnatal hematopoietic stem cell transplantation (HSCT) for congenital hematologic disorders that can be diagnosed early in gestation and can be cured by HSCT. The rationale is to take advantage of normal events during hematopoietic and immunologic ontogeny to facilitate allogeneic hematopoietic engraftment. Although the rationale remains compelling, IUHCT has not yet achieved its clinical potential. This review will discuss recent experimental progress toward overcoming the barriers to allogeneic engraftment and new therapeutic strategies that may hasten clinical application.

Acceptability of In Utero Hematopoietic Cell Transplantation for Sickle Cell Disease

Background. In utero hematopoietic cell transplantation (IUHCT) has curative potential for sickle cell disease (SCD) but carries a risk of fetal demise. Methods. We assessed the conditions under which parents of children with SCD and young adults with SCD would consider IUHCT in a future pregnancy, given a 5% fixed risk of fetal demise. Participants were randomized to consider a hypothetical cure rate (20%, 40%, or 70%). Subsequently, cure rate was either increased or decreased depending on the previous answer to reveal the lowest acceptable rate. Participants also completed the Pediatric Research Participation Questionnaire (PRPQ) and an omission scale. Results. Overall, 74 of 79 (94%) participants were willing to consider IUHCT, and 52 (66%) participants accepted IUHCT at a cure rate of 40%, the estimated rate of therapeutic mixed chimerism. Participants with higher scores on the PRPQ perceived benefits scale were more likely to participate at lower cure rates (OR 1.08, p=0.007) and participants with a greater degree of omission bias were less likely to participate at lower cure rates (OR 0.83, p=0.04). Demographics and SCD severity were not significantly associated with acceptability of IUHCT. Conclusion. This study suggests that the majority of parents >and young adults would consider IUHCT under expected therapeutic conditions.

Outcomes of prenatally diagnosed lung lesions in multigestational pregnancies.

Background: The outcomes of prenatally diagnosed lung lesions in the context of multigestational pregnancies are unknown. Methods: Of 960 fetal lung lesion cases evaluated at a single tertiary center over 16 years, 30 occurred in multigestational pregnancies. We reviewed this series to aid in prenatal counseling of affected families and to provide prognostic information for decision making. Pre- and postnatal clinical characteristics were gathered for these pregnancies, and the morbidity and mortality were determined for both affected and normal fetuses, whether twins or triplets. Results: Mortality was found to be 3/30 (10%) for affected fetuses, and morbidity in normal co-twins was consistent with the degree of prematurity. No morbidity was seen in co-twins born at or after 36 weeks of gestation. Median gestational age at delivery was 35 5/7 weeks. Conclusions: Outcomes for the affected fetus correlate with the size and pathophysiologic consequences of the lesion and are not worse than previously reported outcomes for similar lesions in singleton pregnancies, while morbidity in the normal co-twin is consistent with prematurity related to the fetal age of the multiple gestation at delivery, irrespective of the fetal lung lesion.