Summary:Thrombotic microangiopathy (TMA) usually occurs during the first weeks following transplantation in the setting of systemic infections or graft-versus-host reaction. However, some cases without any evidence of other complications or after autologous transplantation have been reported. Transplant-associated TMA (BMT-TMA) incidence ranges from 0% to 74%, possibly due to different diagnostic criteria. The GITMO Group provided the opportunity to retrospectively study 4334 consecutive Italian patients who received bone marrow transplants (1759 allogeneic and 2575 autologous BMT), during the 1985-1995 period. The present report focuses on patients with severe TMA requiring specific treatment. We identified nine cases of TMA as a complication of allogeneic BMT (0.51%), whereas three patients developed the syndrome after ABMT (0.13%); four of the 12 patients were not receiving CsA at the time of TMA onset. Finally, it is noteworthy that TMA occurred in seven patients as a late complication (up to 90 days after BMT). Despite intensive treatment, five of the seven patients with thrombotic thrombocytopenic purpura died. One death was observed among the five cases with hemolytic uremic syndrome.

No specific characteristics have been identified as predictors of peripheral blood stem cells (PBSC) mobilization in healthy donors. In this study, clinical characteristics and laboratory data for 122 healthy donors who underwent apheresis on day 5 of treatment with recombinant granulocyte colony-stimulating factor (G-CSF) were retrospectively analyzed for correlations with CD34(+) cell mobilization. The variables that were analyzed included age, sex, body weight, basal complete blood count, and maximum white blood count (WBC) before apheresis, G-CSF type, and dosage. Median age and body weight were 42.5 years (range 16-65) and 72.5 kg (range 47-121), respectively. By univariate analysis, male sex (P = 0.007), body weight (< or = 70 vs. >70 kg, P = 0.04), and donor's age (< or = 50 vs. > 50 years; P = 0.015) were correlated with the number of CD34(+) cells mobilized. By multivariate analysis, donor's age and male sex were the only two variables that significantly predicted a high CD34(+) cell level. In conclusion, our data suggest that male sex and younger age are the only factors that significantly affect CD34(+) mobilization in healthy donors.

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Mobilization of CD34+ into peripheral blood is attained by either glycosylated (lenograstim) or non-glycosylated recombinant G-CSF (filgrastim). 101 donors, 57 males, median age 42 years (range 16-63) entered this retrospective study. Group I (55 cases) received filgrastim and group II lenograstim subcutaneously for 5-6 days. The peak number of CD34+ cells/microl blood observed on day 4 and 5 was not significantly different in the two groups. No differences were shown in terms of both circulating CFU-GM at the time of harvesting and CD34+ target of collection. The most frequent side effects were bone pain (18.2% grade I; 36.4% grade II, 7.3% grade III), headache (18.2%), nausea (9.1%), fever (5.5%) and a mild splenomegaly (> 2 cm) (5.5%) in filgrastim group, and bone pain (37.0% grade I, 26.1% grade II, 2.2% grade III), headache (17.4%), nausea (15.2%), fever (4.4%) and a mild splenomegaly (4.3%) in lenograstim group, respectively. CD34+ collection was associated with thrombocytopenia, which was not significantly different between the two groups. No donor in either group developed long-term adverse effects. We conclude that both G-CSFs are comparable in terms of CD34+ cell collection, safety and tolerability.

Background Extremely low gestational age neonates (ELGANs, i.e., neonates born before 28 weeks of gestation) are at high risk of developing retinopathy of prematurity (ROP), with potential long-life visual impairment. Due to concomitant anemia, ELGANs need repeated red blood cell (RBC) transfusions. These produce a progressive replacement of fetal hemoglobin (HbF) by adult hemoglobin (HbA). Furthermore, a close association exists between low levels of HbF and severe ROP, suggesting that a perturbation of the HbF-mediated oxygen release may derange retinal angiogenesis and promote ROP. Methods/design BORN (umBilical blOod to tRansfuse preterm Neonates) is a multicenter double-blinded randomized controlled trial in ELGANs, to assess the effect of allogeneic cord blood RBC transfusions (CB-RBCs) on severe ROP development. Recruitment, consent, and randomization take place at 10 neonatology intensive care units (NICUs) of 8 Italian tertiary hospitals. ELGANs with gestational age at birth comprised between 24+0 and 27+6 weeks are randomly allocated into two groups: (1) standard RBC transfusions (adult-RBCs) (control arm) and (2) CB-RBCs (intervention arm). In case of transfusion need, enrolled patients receive transfusions according to the allocation arm, unless an ABO/RhD CB-RBC is unavailable. Nine Italian public CB banks cooperate to make available a suitable amount of CB-RBC units for all participating NICUs. The primary outcome is the incidence of severe ROP (stage 3 or higher) at discharge or 40 weeks of postmenstrual age, which occurs first. Discussion BORN is a groundbreaking trial, pioneering a new transfusion approach dedicated to ELGANs at high risk for severe ROP. In previous non-randomized trials, this transfusion approach was proven feasible and able to prevent the HbF decrease in patients requiring multiple transfusions. Should the BORN trial confirm the efficacy of CB-RBCs in reducing ROP severity, this transfusion strategy would become the preferential blood product to be used in severely preterm neonates. Trial registration ClinicalTrials.gov NCT05100212. Registered on October 29, 2021