Prenatal selection of cord blood donors according to the estimated fetal weight percentile and new approaches; results of a prospective cohort study.

BACKGROUND: Umbilical cord blood (UCB) donation is becoming inefficient and we recently proposed the estimated fetal weight percentile (EFWp) ≥60th as a predictor for a prenatal selection of donors. The aim of this study is to prospectively validate this and to identify new potential prenatal predictive parameters. STUDY DESIGN AND METHODS: Prospective cohort study of low-risk pregnancies undergoing third trimester ultrasound, whose UCB was collected at delivery (2016-2018) and compared with a historical cohort (2013-2016, N = 869). Several ultrasound parameters (EFWp, amniotic fluid, Doppler evaluation, placental thickness) were assessed ultrasound and perinatal data were collected. The association with standard of high quality of UCB was assessed by logistic regression analysis. RESULTS: Among 297 cases, 161 (54%) were selected according to the EFWp ≥60th for UCB units' collection. Cellular criteria for banking was achieved in 27 cases (16.8%), with an average increase of 1.7 times compared to the historical cohort (9.8%, P = .009). Selecting donors according to the 60th EFWp resulted in a higher probability of collecting clinical suitable UCB (P = .025). Among prenatal and perinatal parameters, EFWp, amniotic fluid, umbilical vein (UV) velocity, newborn weight and percentile and placental weight were significantly associated with a higher cellular content. At logistic regression analysis, significant contributors of UCB collection, were EFWp at 37-38 weeks ultrasound (OR 1.04; 95% CI: 1-1.08; P = .042) and UV velocity (OR 1.14; 95% CI: 1-1.29; P = .037). CONCLUSION: The evaluation of the EFWp equal or above 60 and the increased UV velocity can result in higher efficiency of public UCB donation programs.

Cord blood-derived platelet concentrates as starting material for new therapeutic blood components prepared in a public cord blood bank: from product development to clinical application.

BACKGROUND: There are many advantages to using cord blood (CB) as a source of therapeutic platelet and plasma derivatives for regenerative medicine. These include availability, universal use, young donor source, and virally safe biological material, rich in tissue regenerative factors. MATERIALS AND METHODS: We aimed to validate a bioprocess design for the production of cord blood-derived platelet concentrates (CBPC) in a public Cord Blood Bank (CBB). CBPC was defined as a product of 10±5 mL, 1,000±200×109/L total platelets, free of erythrocytes and leukocytes. A total of 300 CB units were centrifuged in two steps to enrich for platelets, in compliance with Good Manufacturing Practice. The samples were tested for the degree of platelet activation present, and the levels of growth factor were analysed to evaluate their potential function. CBPC were then activated after thawing with 10% calcium gluconate to generate platelet gels (CBPG) to treat patients with diabetic foot ulcers. RESULTS: After processing, 84% of the products fulfilled the acceptance criteria. Final products contained 1,017±149×106 platelets/mL in 10±3mL of plasma. Platelet recovery was 50±9%. The methods described here ensure depletion of white and red blood cells down to a residual concentration of 0.2±0.1×106/mL and 0.03±0.02×106/mL, respectively. Platelets showed low levels of activation during processing, but were significantly activated after thawing, as indicated by an increase in CD62p expression. The growth factors EGF, VEGF, bFGF, PDGF AB/BB and TGF-ß1 were at concentrations of 1,706±123 pg/mL; 1,602±227 pg/mL; 314±26 pg/mL; 30±1.5 ng/mL; 24±2 ng/mL (mean±standard error of mean), respectively. For clinical evaluation, a total of 21 CBPG were applied in 3 patients, with no reported adverse events and improvement of ulcers in all of them. DISCUSSION: We designed and validated a highly reproducible, closed system method to manufacture high quality CBPC suitable for clinical applications using CB units not suitable for transplantation in a public CBB.

First molecular characterization of an unequal homologous alu-mediated recombination event responsible for hemophilia.

The large number of Alu repeats in the human genome provides abundant opportunities for unequal homologous recombination events that are responsible of several human diseases. We here describe a novel large FVIII gene deletion from a severe hemophilia A patient in which Alu-repetitive elements are directly involved in the origin of the mutation. Using a long-fragment PCR method, a approximately 23 kb deletion was delimited between introns 24 and 25. The resulting FVIII gene had a hybrid 2317-bp intron and lacked exon 25. Absence of exon 25 was confirmed at the RNA level. Multiple sequence alignment of this hybrid intron and normal introns 24 and 25 provided evidence of an homologous recombination event between two Alu repeats and the exact breakpoints were delimited to a 16 bp region. To our knowledge, this is the first report of hemophilia caused by unequal homologous Alu/Alu recombination. This mechanism, commonly related to genetic human disorders, may be involved in a significant number of hemophilia cases considering that FVIII is coded by an Alu-rich gene.