Growth differentiation factor 11 (GDF11) - a promising anti-ageing factor - is highly concentrated in platelets.

Recent research suggests that growth differentiation factor 11 (GDF11) could reverse age-related diseases and that its blood concentration decreases with age. This poses plasma from young donors as a therapeutic GDF11 source to treat age-related diseases. In addition, the tissue source of circulating GDF11 remains unknown. We analysed GDF11 levels in paired samples of serum, plasma and platelet lysate (PL) from 23 volunteers. Plasma and PL were collected by plateletpheresis. Here, we show that GDF11 is highly concentrated in platelets and that the circulating levels reported in previous studies could be biased as a result of serum sample manipulation.

[Umbilical cord blood cell transplantation from an unrelated donor: dual transplantation]. / Trasplante de sangre de cordón umbilical más donante auxiliar: trasplante dual.

Our team conducted an original procedure of hematopoietic transplantation of umbilical cord blood (UCB) from an unrelated donor. The procedure consists of co-infusing hematopoietic stem cells selected from the blood of a third-party donor; it is conceived as a tool to shorten the engraftment period without preventing the engraftment of the UCB, even when using units with relatively low cell content and a low HLA compatibility. Between 1999 and 2008 we performed 64 transplantations in 60 adult patients (35 men and 25 women) with a median age of 34 years (range: 76-60) and a median weight of 70 kg (range: 43-95), all of whom were diagnosed with a high risk hematologic neoplasm (leukemia in most cases). Fludarabine, cyclophosphamide, ATG, and whole body irradiation or busulfan were used as conditioners. UCB was infused at medians of 2.4 x 107 CNT/kg (range: 1.14-4.30 x 107), 0.11 x 106 CD34+/kg (range: 0.035-0.37 x 106). Then, hematopoietic stem cells selected from the third-party donor were infused (2.43 x 106/kg [range: 1.05-3.34 x 106], with 0.3 x 104 CD3+/kg [range: 0.05-1.56 x 104]). Granulocyte engraftment occurred (ANC > 0.5 x 109/L) at a median of 10 days (range: 9-34 days), and the granulocyte engraftment of the UCB occurred in 21 days (range: 13-57 days). Complete UCB chimerism was observed in 37 days (range: 11-186 days) (previously double complete chimerism, presence of third-party donor and of cord) and platelet engraftment > 20 x 109/L in 33 days (range: 13 98 days) and > 50 x 109/L in 58 days (range: 14-106 days). Overall 3-year survival reached 51%, and 5 10 year-survival was 47% (plateau). Disease-free survival was 48% at three years, and 45% at 5 to 10 years; the mean follow-up of survivors was 48 months (range: 13-123 months). (Kaplan-Meier). In conclusion, early granulocyte recovery occurred thanks to a foster engraftment of hematopoietic stem from the third-party donor, which are not HLA-restricted; this is associated with a lower morbidity and mortality from infections secondary to neutropenia. There was also a high rate of engraftment and final full UCB chimerism, even with non-histocompatible UCB units (2/6 HLA mismatches) and with relatively low cell counts. In most cases, a single unit of UCB was sufficient. The incidence of severe GVHD and the percentage of relapses have been low. Opportunistic infections have occurred over a long period of time. This procedures makes allogeneic hematopoietic transplantation accessible to almost all patients.

Immune reconstitution after cord blood transplants supported by coinfusion of mobilized hematopoietic stem cells from a third party donor.

Low severity of GVHD, substantial graft vs tumor (GVT) and slow development of protective immunity are well-documented features of cord blood transplants (CBT). We have evaluated the immune reconstitution of adult recipients of single-unit CBT supported by the coinfusion of third party donor (TPD) mobilized hematopoietic stem cells (MHSC), a procedure-'dual CB/TPD-MHSC transplant'-that results in early recovery of circulating granulocytes, high rates of CB engraftment and full chimerism. Cumulative recovery of natural killer and B cells at or above the median values of normal controls were 1.0 and 0.76 by the sixth and ninth months. Recovery of T cells was much slower, naive cells lagging behind those of memory and effector (committed) immunophenotypes. Serial analyses of signal joint TCR excision circles showed a general pattern of very low levels by the third month after CBT, followed by recovery to levels persistently similar or higher than those observed before transplantation and in normal controls. Our results are consistent with the clinical observations of substantial GVT effect together with low incidence of serious GVHD and slow development of protective immunity and suggest that thymic function contributes substantially to the recovery of T-cell populations in adults receiving dual CB/TPD-MHSC transplants.

Cord blood transplants supported by co-infusion of mobilized hematopoietic stem cells from a third-party donor.

This open label clinical study provides updated evaluation of the strategy of single unit cord blood transplants (CBTs) with co-infusion of third-party donor (TPD) mobilized hematopoietic stem cells (MHSC). Fifty-five adults with high-risk hematological malignancies, median age 34 years (16-60 years) and weight 70 kg (43-95 kg), received CBTs (median 2.39 x 10(7) total nucleated cell (TNC) per kg and 0.11 x 10(6) CD34+ per kg) and TPD-MHSC (median 2.4 x 10(6) CD34+ per kg and 3.2 x 10(3) CD3+ per kg). Median time to ANC and to CB-ANC >0.5 x 10(9)/l as well as to full CB-chimerism was 10, 21 and 44 days, with maximum cumulative incidences (MCI) of 0.96, 0.95 and 0.91. Median time to unsupported platelets >20 x 10(9)/l was 32 days (MCI 0.78). MCI for grades I-IV and III-IV acute GVHD (aGVHD) were 0.62 and 0.11; 12 of 41 patients (29%) who are at risk developed chronic GVHD, becoming severely extensive in three patients. Relapses occurred in seven patients (MCI=0.17). The main causes of morbi-mortality were post-engraftment infections. CMV reactivations were the most frequent, their incidence declining after the fourth month. Five-year overall survival and disease-free survival (Kaplan-Meier) were 56 % and 47% (63% and 54% for patients