ALBERT

Description: Abstract 3221 Poster Board III-158 Introduction Umbilical cord blood (UCB) has become an easily, available and viable source of hematopoeitic stem cells for transplant. The main limitation factor for its wide use is cell dose. Previous studies have showed that certain physiological parameters pertaining to either the baby or the mother impact in the UCB cell yields. Objectives The aim of our study was to compare five physiological parameters pertaining to the mother or baby (mother`s age [MA], gestational age at delivery [GA], baby`s gender [G], baby`s birth weight [BW] and type of delivery [TD]) with total nuclear cells (TNC) and CD34 + cells recovery. We also evaluated the impact of time from collection to processing (TCP) on CD45+ cells viability. Methods UCB product collection was performed after the baby's delivery, while the placenta was still in uterus, either from vaginal or cesarean deliveries. Collection bags that were used contained 35 mL of CFDA-1 (CFD with Adenina) as anticoagulant. Cord blood units (CBU) were processed in our institution under local and international regulations regarding cord blood banking. Usual techniques with HES 6% for red cell depletion and 4°C centrifugation for plasma depletion were used. Twenty-five ml, EVA, two-compartment cord blood cells freezing bags (Pall Medical) were used for a final CBU volume of 20.5 ml combined with Dextran 40/40 and DMSO for cryopreservation. A sample was removed for flow cytometric analysis (BD FACSCan) and to determine the TNC (Cell-dyn 1200). Cultures pre and post CBU handling were done. Freezing took place in a controlled-rate freezer according to standard protocol before storage in liquid nytrogen. Results From May 2004 to Jun 2009, a total of 4,262 continous UCB collections were performed in our institution throught the Peruvian Republic. Seventy-eight percent of the CBU were collected by cesarean; median TCP was 30 hours 58 minutes. The mean CBU volume and TNC count were 81.8 ml and 8.63 × 108 respectively. The colected volume was greater in cesarean than vaginal delivery (85.3 ml vs 78.9, F=30.82, p

Description: BACKGROUND: Foxp3 is a key regulatory gene required for the development and function of: regulatory CD4+CD25high T cells (Treg) specialized in maintaining the balance between immunity and tolerance and activated conventional CD4+CD25low T cells without suppressive activity. Until now it is not yet possible to study human FOXP3+ Treg irrespective of their CD25 expression. Previous studies had reported FOXP3+ T cells in Adult T-cell Leukemia/Lymphoma cells (ATLL) related to HTLV-1 and in other lymphomas types the FOXP3 expression was only detected in the reactive T-cell background. AIM: To determine the specifity and prognostic value of the FOXP3 expression in T-cell lymphomas. METHODS: A retrospective study was performed on 46 samples collected from diverse T-cell lymphomas in our institution. A highly sensitive immunohistochemical method was used to demonstrate FOXP3 protein expression with a mouse monoclonal antibody (clone 236A/E7ABCAM) in most formalin-fixed paraffin-embedded tissue sections from lymph nodes, skin, bone marrow and extranodal sites samples as cavum and stomach. We did not co-stained with CD25 and considered a FOXP3+ tissue when positivity was 〉 80% of toumor cells. Correlation with survival was done. RESULTS: Among the 46 evaluable T-cell lymphomas collected, 33 were ATLL, 7 mycosis fungoids (MF) and 6 unspecified peripheral T-cell lymphomas (U-PTCL). Among the 33 ATLL: lymphomatous=17, acute=11, smoldering=1, chronic=1, cutaneous=1 and undefined=2. FOXP3 expression in tumour cells was detected in 24% (8/33) of ATLL cases, was negative in MF tumour cells and detected in 33% (2/6) of U-PTCL. Interestingly FOXP3 expression between 30–40% was expressed in 3 MF cases associated to Treg cells. Among the ATLL cases FOXP3 positivity were obtained in 35% (6/17) of lymphomatous type; 18% (2/11) of acute ones and none in others ATLL types studied. We failed to demonstrated any correlation between FOXP3 status and survival. CONCLUSIONS: FOXP3 is expressed in ATLL and T-cells peripheral lymphoma. Treg presence in the tumour environment plays an important immune system response role and its identification should be fundamental.