Asunto(s)

RESUMEN

Graft failure remains a severe complication of hematopoietic stem cell transplantation (HSCT). Several risk factors have already been published. In this study, we re-evaluated them in a large cohort who had the benefit of the recent experience in HSCT (2006-2012). Data from 4684 unrelated donor HSCT from 2006 to 2012 were retrospectively collected from centers belonging to the French Society for Stem Cell Transplantation. Among the 2716 patients for whom HLA typing was available, 103 did not engraft leading to a low rate of no engraftment at 3.8%. In univariate analysis, only type of disease and status of disease at transplant for malignant diseases remained significant risk factors (P=0.04 and P<0.0001, respectively). In multivariate analysis, only status of disease was a significant risk factor (P<0.0001). Among the 61 patients who did not engraft and who were mismatched for 1 HLA class I and/or HLA-DP, 5 donor-specific antibodies (DSAs) were detected but only 1 was clearly involved in graft failure, for the others their role was more questionable. Second HSCT exhibited a protective although not statistically significant effect on OS (hazard ratio=0.57 [0.32-1.02]). In conclusion, only one parameter (disease status before graft) remains risk factor for graft failure in this recent cohort.

Asunto(s)

RESUMEN

We retrospectively analyzed the impact of HLA-DPB1 mismatches in a large cohort of 1342 French patients who underwent 10/10 HLA-matched unrelated HSCT. A significant impact of HLA-DPB1 allelic mismatches (2 vs 0) was observed in severe acute GVHD (aGVHDIII-IV) (risk ratio (RR)=1.73, confidence interval (CI) 95% 1.09-2.73, P=0.019) without impact on OS, TRM, relapse and chronic GVHD (cGVHD). According to the T-cell epitope 3 (TCE3)/TCE4 HLA-DPB1 disparity algorithm, 37.6% and 58.4% pairs had nonpermissive HLA-DPB1, respectively. TCE3 and TCE4 disparities had no statistical impact on OS, TRM, relapse, aGVHD and cGVHD. When TCE3/TCE4 disparities were analyzed in the graft-vs-host or host-vs-graft (HVG) direction, only a significant impact of TCE4 nonpermissive disparities in the HVG direction was observed on relapse (RR=1.34, CI 95% 1.00-1.80, P=0.048). In conclusion, this French retrospective study shows an adverse prognosis of HLA-DPB1 mismatches (2 vs 0) on severe aGVHD and of nonpermissive TCE4 HVG disparities on relapse after HLA-matched 10/10 unrelated HSCT.

Asunto(s)

RESUMEN

UNLABELLED: New therapies for children with high risk neuroblastoma are needed, and haploidentical stem cell transplantation with NK post-graft injections is a potential option. To develop this strategy, we compared and correlated two methods of NK cytotoxicity assay. The aim of this work is to optimize in vitro NK cytotoxicity assays, investigate the effect of interleukin stimulation on NK cells and use of antiGD2 antibodies against tumor target cells and finally establish an in vitro model for haploidentical stem cell transplantation. EXPERIMENTAL DESIGN: We evaluated NK cell cytotoxicity in vitro against NB cell lines (IMR-32 and SK-NSH) in different culture conditions using a Europium BATDA fluorescence test, and correlated the results with quantification of TH, Phox2B, and DCX transcripts evaluated by RT-PCR. RESULTS: Both IMR-32 and SK-N-SH neuroblastoma cell lines were sensitive to NK cells and particularly when NK cells were stimulated by interleukin IL-2 and IL-15 or when using anti-GD2 antibodies against tumor target cells. All these results were observed either with Europium fluorometry assay or with RT-PCR quantification. There is a clear correlation between the two methods, for the three transcripts at the ratio effector/target 50/1 (TH r=0.75, Phox2B r=0.79 and DCX r=0.8), for all the values whatever the cell line. Besides for all three transcripts, the correlations were significantly independent of the cell line and the ratio E/T (all p values non-significant) even if the best correlation was observed for the ratio 50/1. After prolonged incubation times of effector and target cells (24 h), which could be evaluated only by RT-PCR, all the transcripts clearly decreased, confirming the haploidentical effect of NK against the two neuroblastoma cell lines in our two in vitro haploidentical models but no advantage of mismatch. CONCLUSIONS: NK cytotoxicity against neuroblastoma cell lines can be evaluated by Europium assay and by RT-PCR with clear correlation for the three transcripts TH, Phox2B and DCX whatever the ratio E/T and cell line used. This new method of RT-PCR is simple and suitable for large-scale conditions like study of adherent tumor cells or prolonged incubations of target/effector cells which allowed us to observe haploidentical effect.

Asunto(s)

RESUMEN

The latest generation of cell separators such as Trima (Gambro), Amicus (Baxter) and AS-TEC 204 (Fresenius), allow the collection of leucocyte-reduced platelet concentrates without secondary filtration. Fresenius has recently developed the COMTEC cell separator whose performance has been evaluated by several teams in France. This new cell separator is an improved version of the Fresenius AS-TEC 204 cell separator, designed to allow more efficient platelet collections. This study reports on the experience of six French teams (from Bordeaux, Clermont-Ferrand, Creteil, Dijon, Lille and Nancy) who obtained 696 leucocyte-reduced plateletpheresis concentrates in the course of collection using the new Fresenius COMTEC cell separator. All healthy volunteer donors fulfilled French selection criteria for platelet apheresis. Donors were eligible if they had suitable venous accesses, if their bodyweight was *50 kg and if their pre-apheresis platelet count was >150 x 10(9) l(-1). Between 4606 and 5229 ml of blood were processed. The mean volume of the platelet concentrates was between 439 and 493 ml (mean 460 +/- 63 ml). The platelet yield was of the order of 5.18 +/- 1.02 x 10(11) with only one platelet concentrate below the norm of 2 x 10(11) platelets (0.91 x 10(11)). No plausible explanation for this was found. The residual leucocyte levels conform to current norms. The platelet concentrates contained less than 1 x 10(6) leucocytes per concentrate (mean 0.233 +/- 0.150 x 10(6) leucocytes) in more than 97% of the components produced with >95% statistical confidence. The efficacy of the cell separator (52.44 +/- 7.35%) is comparable to that of other separators. The Fresenius COMTEC cell separator makes it possible to obtain leucocyte-reduced platelet concentrates which comply with current standards both in terms of platelet content and residual leucocyte level.

Asunto(s)

RESUMEN

OBJECTIVES: Cold agglutinins and cryoglobulins are uncommon in the same patient as observed in our case. CASE REPORT: A 74-year-old patient suffered repeated episodes of hemolytic anemia for one year and had hepatitis C anti-virus antibodies. Mixed cryoglobulinemia was found at levels which increased during episodes of acute hemolysis in addition to anti-I cold agglutinins. Two-dimensional electrophoresis revealed identical oligoclonal cold agglutinins and cryoglobulins. DISCUSSION: Unlike mixed cryoglobulinemia, cold agglutinins are not known to occur subsequent to hepatitis C infection. The identical immunoglobulins observed in our patient suggest a common origin. Chronic anti-I cold oligoclonal agglutinins are rarely observed and could be an intermediary step towards monoclonal lymphopathy as has been described in prolonged hepatitis C infection.

Asunto(s)

RESUMEN

Highly fluorescent reticulocyte (HFR) counts and reticulocyte counts were analyzed daily using a Sysmex R-1000 automated reticulocyte counter after 42 BMT in children (median age 7 years, range 10 month-18.5 years). White blood cell levels were also analyzed daily using either traditional counting methods or, when levels were very low, cytocentrifuge preparations. Twenty-eight patients received autologous and 14 allogeneic BMT. After myeloablative therapy, HFR counts fell to zero and rose to 2% of the reticulocyte total after a median time of 10 days (range 6-23 days) post-autoBMT and 14 days (range 9-29 days) post-alloBMT. The appearance of HFR (at least 2% in two successive counts) preceded the attainment of 20 x 10(9)/l reticulocytes in 23 of 26 autoBMT by a median time of 3 days, and in 13 of 13 alloBMT with a median time of 4 days (p < 0.001). Two per cent HFR preceded the attainment of 0.5 x 10(9)/l neutrophils in the majority of BMT by a median time > 6 days (p < 0.001). The attainment of 0.05 x 10(9)/l monocytes was preceded by a rise in HFR in 12 of 26 autoBMT and in 7 of 13 alloBMT. Median times between 2% HFR and monocyte levels of 0.05 x 10(9)/l were respectively 2 (range 0- > 24) and 3 (range: 0- > 19) days after auto and alloBMT. These results show that the evaluation of erythropoiesis following BMT by means of HFR counting provides an early measure of hematopoietic reconstitution which is as precise and considerably more practical than monitoring the monocyte level.

Asunto(s)