Fetal allotransplant recipients are resistant to graft-versus-host disease.

In utero hematopoietic cell transplantation (IUHCT) is an experimental treatment for congenital hemoglobinopathies, including Sickle cell disease and thalassemias. One of the principal advantages of IUHCT is the predisposition of the developing fetus toward immunologic tolerance. This allows for engraftment across immune barriers without immunosuppression and, potentially, decreased susceptibility to graft-versus-host disease (GVHD).

Twin-twin transfusion syndrome - a University Hospital experience with intrauterine treatment.

Introduction: twin-to-twin transfusion syndrome (TTTS), defined by combination of polyhydramnios-oligohydramnios, is the most prevalent (5%-35%) of the abnormalities due to placental vascular anastomoses and the most lethal (80%-100% mortality) if untreated. Fetoscopic laser ablation of abnormal vasculature using the Solomon technique is the gold standard approach. It consists of interrupting the intertwin blood flow.

Regulatory T cells promote alloengraftment in a model of late-gestation in utero hematopoietic cell transplantation.

In utero hematopoietic cell transplantation (IUHCT) has the potential to cure congenital hematologic disorders including sickle cell disease. However, the window of opportunity for IUHCT closes with the acquisition of T-cell immunity, beginning at approximately 14 weeks gestation, posing significant technical challenges and excluding from treatment fetuses evaluated after the first trimester. Here we report that regulatory T cells can promote alloengraftment and preserve allograft tolerance after the acquisition of T-cell immunity in a mouse model of late-gestation IUHCT.

Donor cell engineering with GSK3 inhibitor-loaded nanoparticles enhances engraftment after in utero transplantation.

Host cell competition is a major barrier to engraftment after in utero hematopoietic cell transplantation (IUHCT). Here we describe a cell-engineering strategy using glycogen synthase kinase-3 (GSK3) inhibitor-loaded nanoparticles conjugated to the surface of donor hematopoietic cells to enhance their proliferation kinetics and ability to compete against their fetal host equivalents. With this approach, we achieved remarkable levels of stable, long-term hematopoietic engraftment for up to 24 weeks post-IUHCT.

Open Versus Laparoscopic Splenectomies in Children: A Comparative Study Performed at a Public Hospital in Brazil.

In pediatric population, the two most common indications for splenectomy include traumatic rupture and hematological diseases such as hereditary spherocytosis, idiopathic thrombocytopenic purpura, sickle cell disease, and autoimmune hemolytic anemia. Traditionally, splenectomy has been an open procedure; however, since the first laparoscopic splenectomy was reported in 1991, the minimally invasive laparoscopic approach has become increasingly popular. In most public hospitals in Brazil, where vessel sealing devices are not available, most surgeons seem to prefer open splenectomy to guarantee intraoperative safety and improved outcomes.

In Utero Transplantation of Expanded Autologous Amniotic Fluid Stem Cells Results in Long-Term Hematopoietic Engraftment.

In utero transplantation (IUT) of hematopoietic stem cells (HSCs) has been proposed as a strategy for the prenatal treatment of congenital hematological diseases. However, levels of long-term hematopoietic engraftment achieved in experimental IUT to date are subtherapeutic, likely due to host fetal HSCs outcompeting their bone marrow (BM)-derived donor equivalents for space in the hematopoietic compartment. In the present study, we demonstrate that amniotic fluid stem cells (AFSCs; c-Kit+/Lin-) have hematopoietic characteristics and, thanks to their fetal origin, favorable proliferation kinetics in vitro and in vivo, which are maintained when the cells are expanded.