Solvent-detergent filtered (S/D-F) fresh frozen plasma and cryoprecipitate minipools prepared in a newly designed integral disposable processing bag system.

Solvent-detergent (S/D) viral inactivation was recently adapted to the treatment of single plasma donations and cryoprecipitate minipools. We present here a new process and a new bag system where the S/D reagents are removed by filtration and the final products subjected to bacterial (0.2 microm) filtration. Recovered and apheresis plasma for transfusion (FFP) and cryoprecipitate minipools (400 +/- 20 mL) were subjected to double-stage S/D viral inactivation, followed by one oil extraction and a filtration on a S/D and phthalate [di(2-ethylhexyl) phthalate (DEHP)] adsorption device and a 0.2 microm filter. The initial and the final products were compared for visual appearance, blood cell count and cell markers, proteins functional activity, von Willebrand factor (VWF) multimers and protein profile by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Tri (n-butyl) phosphate (TnBP) was quantified by gas chromatography and Triton X-45 and DEHP by high-performance-liquid chromatography (HPLC). General safety tests were by 6.5 mL/kg intravenous injection in rats. The treated plasmas and cryoprecipitates were very clear and the protein content and functionality, VWF multimers and SDS-PAGE profiles were well preserved. TnBP and Triton X-45 were < 1 and <25 ppm, respectively, and DEHP (about 5 ppm) was less than it was in the starting materials. Blood cell counts and CD45, CD61 and glycophorin A markers were negative. There was no enhanced toxicity in rats. Thus, plasma and cryoprecipitate can be S/D-treated in this new CE-marked disposable integral processing system under conditions preserving protein function and integrity, removing blood cells, S/D agents and DEHP, and ensuring bacterial sterility. This process may offer one additional option to blood establishments for the production of virally inactivated plasma components.

Impact of CD34 subsets on engraftment kinetics in allogeneic peripheral blood stem cell transplantation.

Our objective was to evaluate, probably for the first time, the impact of CD34 subsets on engraftment kinetics in allogeneic PBSC transplantation (PBSCT). PBSC graft components were analyzed in 62 cases for the absolute count/kg of total CD34+ and the following subsets: DR- and +, CD71+/-, CD38+/-, CD33+/- and CD61+/-. Time to ANC >0.5 and >1 x 10(9)/l and platelets >20 and >50 x 10(9)/l was reported. The median value for each parameter was used to discriminate rapid from slow engraftment. Four parameters showed significant predictive power of early neutrophil engraftment, namely CD34+ /DR- (P = 0.002), CD34+/38- (P = 0.02), CD34+/CD61- (P = 0.04) and total CD34+ cell dose (P = 0.04). Four parameters showed significant predictive power of early platelet engraftment, namely CD34+/CD61+ (P = 0.02), CD34+ /CD38- and total CD34+ cell dose (P = 0.04) and CD34+ /CD71- (P = 0.05). Comparing patients who received > to those who received < the threshold dose(s), only CD34+ /CD38- lost its significance for neutrophil engraftment; and only CD34+ /CD61+ retained its significance for platelet engraftment (P = 0.03); furthermore, the former group required significantly fewer platelet transfusions (P = 0.018). We concluded that in allogeneic PBSCT, the best predictor of early neutrophil engraftment is the absolute CD34+ /DR- and for early platelet engraftment is the absolute CD34+ /CD61+ cell dose.

Molecular epidemiology of acute lymphoblastic leukemia in Egypt.

We have characterized immunophenotypically defined acute lymphoblastic leukemia (ALL) in Egypt for rearrangements of the antigen receptor genes, and correlated this with rearrangements of ALL-1 and the presence of p53 mutations. Thirty-nine cases were analyzed for rearrangements of the immunoglobulin (Ig) and T-cell receptor (TCR) genes. All precursor B-cell ALLs (12 cases) contained rearranged Ig heavy-chain (JH) region which was biallelic in 92% of these tumors. In addition to JH rearrangements, TCR delta, beta and gamma rearrangements were observed in 80, 40 and 30% of these cases, respectively. TCR genes were invariably rearranged in T-cell ALLs (11 cases). A small fraction (2/11) of T-cell ALL showed concurrent IgJH rearrangement which was monoallelic. Simultaneous rearrangement of IgJH and TCR genes was also observed in both cases of biphenotypic ALL (coexpressing B and T markers). We observed marked heterogeneity in the pattern of rearrangement of antigen receptor genes in mixed-lineage leukemias (ALL coexpressing myeloid-associated markers), including the retention of germline configuration in two cases. Rearrangements of the ALL-1 gene were confined to the leukemias that demonstrated lineage infidelity. Mutations in p53 were infrequent and were present in only three of 47 ALL cases (6%) analyzed; two of these were mixed-lineage leukemias. These results suggest that mixed-lineage and biphenotypic leukemias accumulate pathogenetic lesions that are distinct from B- and T-cell ALL, and that ALL in developing countries includes molecular entities similar to those in developed countries.