Comparison of plasma exchange performances between Spectra Optia and COBE Spectra apheresis systems in repeated procedures considering variability and using specific statistical models.

Repeated therapeutic plasma exchange (TPE) procedures using centrifugation techniques became a standard therapy in some diseases. As the new device Spectra Optia (SPO; Terumo BCT) was available, we studied its performances in repeated procedures in 20 patients in three apheresis units. First we analysed the performance results obtained by SPO. Second we compared the performances of the SPO device to a standard device, COBE Spectra (CSP; Terumo BCT) in the same patients using statistical method of mixed effects linear regression that considers variability between patients, centres and apheresis procedures. The performances analysed were classified according to plasma removal performances and their consequences on patients whose blood disturbances were assessed. Primary outcome was plasma removal efficiency (PRE) and PRE-anticoagulant corrected which was a more accurate parameter. Secondary outcomes corresponded to the volume of ACD-A consumed, platelets content in waste bag, procedure duration and status of coagulation system observed after TPE sessions. Before comparing the performances of both devices we compared the plasma volumes (PVs) processed in both techniques which showed that the PVs processed in SPO procedures were lower than in CSP procedures. In these conditions the statistical analysis revealed similar performances in both apheresis devices in PRE (p = ns) but better performances with SPO when considering higher PRE corrected by anticoagulant volume used (p < 0.05). Comparison of secondary outcomes showed no difference after SPO and CSP. After verifying that pre-apheresis patients' coagulation blood levels were identical before SPO and CSP, we showed identical haemostasis disturbances after SPO and CSP but lower platelet losses and higher fibrinogen post-apheresis blood levels after SPO (p < 0.05). No side effects or technical complications occurred during and after SPO and CSP. This study demonstrated that the Spectra Optia device is an alternative device to today's standard, the COBE Spectra device.

[Association of red blood cell and platelet allo-antibodies in platelet alloimmunized patients]. / Association d'allo-anticorps anti-érythrocytaires et anti-plaquettes chez les patients avec allo-immunisation anti-plaquettaire.

PURPOSE OF THE STUDY: Use of matched red blood cell (RBC) concentrates is imperative in patients with RBC allo-antibodies (Abs) and when platelet (PLT) specific allo-Abs are present additional difficulties occur for PLT transfusions. In order to evaluate the prevalence of the PLT and RBC allo-Abs association, a study on patients with PLT specific allo-Acs was performed. This association is not a rare event. PATIENTS AND METHODS: In the database of a PLT immunohaematology laboratory, patients with PLT specific allo-Abs were selected and the presence and specificity of RBC allo-Abs was evaluated. RESULTS: Six hundred and eighty seven patients (673 females, 14 males) with PLT specific allo-Abs were found. Six hundred and seventy-five patients (98.3%) had PLT specific allo-Abs with only one specificity. Anti-HPA-5b was the most frequent (539 cases). Twenty-nine (4.2%) patients had also RBC allo-Abs, including 27 females (93.1%) and two males. Seventy (58.6%) had RBC allo-Abs with only one specificity, 10 several and two unknown. Among the first, RBC allo-Abs directed against Rhesus blood group antigens were predominant (11 cases [64.7%]). Among the 29 patients with associated PLT and RBC allo-Abs, 15 (51.7%) were 50 or more years old and 14 (48.3%) under 50. CONCLUSION: In PLT specific alloimmunized patients, detection of RBC alloimmunization is not a rare event. When RBC and PLT transfusions are required, the supply of matched RBC and PLT concentrates is more difficult.

[Non-invasive fetal RHD genotyping: Validation of the method with 200 patients]. / RHD fœtal sur plasma maternel : validation de méthode sur 200 patientes.

BACKGROUND: Non-invasive fetal RHD genotyping is an important tool to assess the risk of fetuse's hemolytic disease of anti-D allo-immunized pregnant woman by non-invasive method. A method of genotyping has been developed in the laboratory of Lyon-GHE according to Minon's team (J Gynecol Obstet Biol Reprod 2005): exon 4, 5, and 10 are amplified by real time PCR. At first, genotyping results of 200 pregnant women have been compared with RH1 phenotype at birth. The most important parameters of validation have been tested: the sensibility and the specificity; the negative predictive value; the correlation study permitted to define criteria of biological interpretation. The validation of this method permitted to determine critical points and the limits of the method due to the minor amount of fetal DNA in the maternal plasma and existence of many variant forms of the RHD gene. CONCLUSION: We worked too in the perspective to the accreditation for our genetic laboratory.

Development of model for analysing respective collections of intended hematopoietic stem cells and harvests of unintended mature cells in apheresis for autologous hematopoietic stem cell collection.

Hematopoietic stem cells (HSCs) required to perform peripheral hematopoietic autologous stem cell transplantation (APBSCT) can be collected by processing several blood volumes (BVs) in leukapheresis sessions. However, this may cause granulocyte harvest in graft and decrease in patient's platelet blood level. Both consequences may induce disturbances in patient. One apheresis team's current purpose is to improve HSC collection by increasing HSC collection and prevent increase in granulocyte and platelet harvests. Before improving HSC collection it seemed important to know more about the way to harvest these types of cells. The purpose of our study was to develop a simple model for analysing respective collections of intended CD34+ cells among HSC (designated here as HSC) and harvests of unintended platelets or granulocytes among mature cells (designated here as mature cells) considering the number of BVs processed and factors likely to influence cell collection or harvest. For this, we processed 1, 2 and 3 BVs in 59 leukapheresis sessions and analysed corresponding collections and harvests with a referent device (COBE Spectra). First we analysed the amounts of HSC collected and mature cells harvested and second the evolution of the respective shares of HSC and mature cells collected or harvested throughout the BV processes. HSC collections and mature cell harvests increased globally (p<0.0001) and their respective shares remained stable throughout the BV processes (p non-significant). We analysed the role of intrinsic (patient's features) and extrinsic (features before starting leukapheresis sessions) factors in collections and harvests, which showed that only pre-leukapheresis blood levels (CD34+cells and platelets) influenced both cell collections and harvests (CD34+cells and platelets) (p<0.001) and shares of HSC collections and mature unintended cells harvests (p<0.001) throughout the BV processes. Altogether, our results suggested that the main factors likely to influence intended HSC collections or unintended mature cell harvests were pre-leukapheresis blood cell levels. Our model was meant to assist apheresis teams in analysing shares of HSC collected and mature cells harvested with new devices or with new types of HSC mobilization.

[Prevalence of platelet-specific antibodies in the recipients of platelet units with transfusion adverse event]. / Prévalence des anticorps antiplaquettes spécifiques chez les receveurs de concentrés plaquettaires avec effet indésirable transfusionnel.

PURPOSE OF THE STUDY: In practice, platelet transfusions are frequently performed in patients with haematologic and/or oncologic diseases. Subsequent to these transfusions, platelet specific antibodies may develop and could induce adverse events, such as platelet transfusion refractoriness or post-transfusion purpura. In order to evaluate the prevalence of platelet specific antibodies in these recipients, adverse events with a request for platelet specific antibodies testing, were studied. PATIENTS AND METHODS: Recipients of platelet units with adverse event, excluding platelet transfusion refractoriness or post-transfusion purpura, were evaluated. RESULTS: From January 1st 2009 to October 31st 2011, 125 adverse events with platelet specific antibodies screening, corresponding to 116 recipients (64 females, 52 males) were included. The main aetiology of the adverse event was a febrile non-haemolytic transfusion reaction in 62 cases (49.6%) and allergy in 40 (32.0%). Most samples tested were post-transfusion solely (101 adverse events, 80.8%). Seven of these samples had free platelet specific antibodies, including four anti-HPA-5b, one anti-HPA-2a and two anti-GPIaIIa. In the cross-match test, platelet specific antibodies were found in two pre-transfusion samples (anti-GP IaIIa) and in five post-transfusion samples (anti-GPIaIIa, three cases; anti-GP IbIX, one case; anti-GP IIbIIIa and -GPIbIX, one case). CONCLUSION: According to this study on platelet transfusion related adverse event, few platelet specific antibodies were detected on pre- and post-transfusion samples. The implementation of platelet specific antibodies testing before transfusion would give more accurate data and help prevent adverse events as typed platelets would be given when platelet specific antibodies were found.

[Chimerism analysis after allogeneic haematopoietic stem cell transplantation. Interest of cell sorting: general review]. / Étude de chimérisme post-greffe de cellules souches hématopoïétiques. Intérêt du tri cellulaire : revue générale.

Haematopoietic stem cells transplantation, widely used these last decades, represent the ultimate treatment resource for patients with haematological malignancies. Long range success of this treatment is particularly affected by relapse of the initial disease, graft rejection or graft versus host disease. Chimerism analysis after transplantation had been used since several years to document engraftment, to determine the risk of relapse and to adapt therapy promptly when necessary. Usefulness of this analysis for the outcome of transplanted patients, as well as the impact of using high sensitive techniques coupled with specific cell populations sorted have been demonstrated by retrospective studies. Follow-up of chimerism would allow to operate efficiently before the onset of clinical signs in leukaemic patients with high risk of relapse and to control the expression of minimal residual disease when specific molecular markers could not be monitored.

[Monitoring of chimerism in myeloid cells sorting of transplanted patients with acute myeloid leukaemia: a study from Lyon (France)]. / Suivi de chimérisme des populations cellulaires myéloïdes chez des patients allogreffés atteints de leucémie aiguë myéloïde : étude lyonnaise.

Chimerism analysis after allogeneic haematopoietic stem cell transplantation has been used to document engraftment and to adapt therapy promptly. The aim of this study was to document engraftment and to detect as soon as possible relapse in patients with acute myeloid leukaemia who underwent stem cell transplantation. Real-time quantitative polymerase chain reaction is a highly sensitive and reproducible technology. It is useful in some disease to target selected sub-populations in order to have an earlier detection of relapse on cell fractions. In the acute myeloid leukaemia (n=65), analysis of the chimerism on whole peripheral blood cells and bone marrow cells, CD3+ cells, specific myeloid CD33+ cells (from blood) and CD34+ cells (from bone marrow) is of importance. After transplant, 25 patients relapsed (38%), three massively, with chimerism detection in whole blood and bone marrow and 22 insidiously following two different schemes (GRI and GRII). In GRI, (n=13): chimerism of CD33+ and CD34+ cellular fractions allowed an early detection of relapse in 100% of cases undetected in whole cells whereas in GRII (n=9): myeloid cells could identified relapse in 89% of cases when whole blood cells and CD3+ cells expressed a mixed chimerism. This study highlighted the importance of sub-cellular population chimerism documentation enable to ascertain a stable engraftment and to detect early relapse. The selection of sub-cellular population studied with high sensitive technology allows a rapid and efficient intervention before the onset of clinical signs in patient with acute myeloid leukaemia and could improve the patient's follow-up.

Impact of pretransplant human leukocyte antigen-C and -DP antibodies on kidney graft outcome.

The aim of our study was to determine whether the presence of specific human leukocyte antigen (HLA)-C and -DP antibodies before transplantation influenced graft outcomes in immunized recipients. Two groups of pretransplant immunized recipients were studied: patients with only classical HLA-A, -B, -DR, -DQ antibodies (n = 176) and those with classical plus HLA-C and/or -DP antibodies (n = 27). Acute antibody-mediated rejection was preferentially associated with the presence of pretransplant anti-HLA-C and -DP antibodies (5/6 cases). In four cases, acute rejection episodes were followed by graft loss within 15 months after transplantation. There was a significant increase in the number of acute rejection episodes especially antibody-mediated acute rejections (P = .036) and in the number of graft losses for immunologic reasons (P < .001) among the group with pretransplant anti-C and -DP antibodies. Pretransplant anti-DP antibodies seemed to be involved more frequently in poor graft outcomes as shown in several recent published cases. We need to investigate their specific role among a larger cohort, taking into account an epitope analysis.

Multiplexed immunoassay for the rapid detection of anti-tumor-associated antigens antibodies.

TAAs (tumor-associated antigens) microarrays were designed to detect auto-antibodies directly in patient sera. Twelve different probes were chosen according to their described occurrence in cancer pathologies (Cyclin B1, Cyclin D1, Complement factor H, c-myc, IMP1, p53, p62, survivin, Her2/neu, Koc, NY-ESO-1 and PSA). Microarrays of these 12 proteins were immobilized within the nitrocellulose/cellulose acetate membrane of a 96-well filtering microtiter plate bottom. The captured auto-antibodies were detected using a staining approach based on alkaline phosphatase labeling. Thus, the presence of specific auto-antibodies in samples was visualized through the positive staining of the corresponding TAA spots. The TAA HiFi microarrays were shown to be able to capture specific purified anti-TAA antibodies. In real samples, 9 proteins from the 12 TAAs panel were shown to generate specific signal and 5 antigens (p53, NY-ESO-1, IMP1, cyclin B1 and c-myc) were shown to have interaction with more than 10% of the positive sera from cancer patients. This protein subpanel was proven to be able to detect 72.2% of the cancer patients tested (within a 34 panel of 18 patients and 16 healthy donors).

[Autoimmune haemolytic anemia: diagnosis strategy and new treatments]. / Anémies hémolytiques auto-immunes: diagnostic biologique et nouvelles approches thérapeutiques.

The pattern of autoimmune hemolytic anemia has changed significantly these last 15 years. With regard to the diagnosis strategy, the use of gel filtration technique to perform the direct antiglobulin test (DAT) has decreased the number of autoimmune haemolytic anemias with negative tests results. In recent years, autoimmune haemolytic anemia increased in patients receiving purine nucleoside analogues, blood transfusions, solid organ transplantation or hematopoietic stem cells transplantation. These difficult autoimmune haemolytic anemia cases need to use new kinds of treatments. With regard to the treatment, very little progress was made this latter 50 years. The discovery of the efficacy of anti-CD20 antibody in this disease represents a breakthrough. Nowdays, the second-line treatment includes rituximab or splenectomy. Sometimes, the anti-CD20 treatment could be proposed in first-line but some clinical trials are needed.

The first results demonstrating efficiency and safety of a double-column whole blood method of LDL-apheresis.

LDL-apheresis is a treatment for familial hypercholesterolemia in addition to diet and drug therapy. In the past, LDL-apheresis techniques consisted in separating plasma from blood and adsorbing plasma LDL-C whereas recent methods remove LDL-C directly from whole blood. The whole blood system developed by Kaneka consists of a single-column (Liposorber DL-75) treatment (SCWB) but a double-column whole blood (DCWB) method has recently been developed (Liposorber DL-50 x 2). When 1.6 blood volumes (plus 1l) were processed, acute reductions of total cholesterol and LDL-C were 67.9+/-6% and 80.2+/-4.5%, respectively. The performances of the DCWB method were compared to other LDL-apheresis methods. Assessed in 10 patients, the DCWB method is more efficient than the SCWB method with higher reduction rates of LDL-C (79.7+/-4.9 vs. 68.2+/-5.0% p<0.0001) and apolipoprotein-B (79.5+/-5.4 vs. 67.4+/-5.4% p<0.0001). In a sub group of five patients having the highest LDL-C baseline levels, the LDL-C reduction rates obtained by the DCWB method are equivalent to those obtained by the conventional LDL-apheresis method consisting of preliminary plasma separation followed by plasma LDL-C adsorption and used as first line apheresis therapy (80.5+/-4.5 vs. 79.0+/-5.9%). The safety of DCWB was demonstrated in 12 patients with only a low frequency of mild and transient adverse effects (4%). In conclusion, the DCWB LDL-apheresis method provides efficient removal of LDL-C, a low level of adverse effects, and a shortened duration of the procedure.

[Towards an industrial control of the cloning of lymphocytes B human for the manufacturing of monoclonal antibodies stemming from the human repertoire]. / Vers une maîtrise industrielle du clonage des lymphocytes B humains pour la fabrication des anticorps monoclonaux issus du répertoire humain.

Monoclonal antibodies (mAbs) are efficient drugs for treating infectious, inflammatory and cancer diseases. Antibodies secreted by human lymphocytes that have been isolated from either peripheral blood or tissues present the definite interest of being part of the physiological or disease-related response to antigens present in the human body. However, attempts to generate hybridomas with human B cells have been largely unsuccessful, and cloning of human B cells has been achieved only via their inefficient immortalization with Epstein Barr Virus (EBV). However, recent progress in our understanding of the molecular mechanisms of polyclonal B cell activation has dramatically increased the capacity to clone human B cells. In particular, activation of human naïve and memory B cells through CD40 or memory B cells only through TLR9 was shown to greatly facilitate their immortalization by EBV. Industrial development based on these observations will soon provide large collections of high affinity human mAbs of every isotype directly selected by the human immune system directed to recognize epitopes relevant for individual patients. Moreover, after CD40 activation, these mAbs will cover the full human repertoire, including the natural auto-immune repertoire. Full characterization of the biological activity of these mAbs will in turn bring useful information for selecting vaccine epitopes. This breakthrough in human B cell cloning opens the way into new areas for therapeutic use of mAbs.

Tear concentrations of azithromycin following topical administration of a single dose of azithromycin 0.5%, 1.0%, and 1.5% eyedrops (T1225) in healthy volunteers.

PURPOSE: To evaluate azithromycin tear concentrations after one drop of T1225 0.5%, 1.0%, and 1.5% eyedrops. METHODS: In this randomized, double-masked study, 91 healthy volunteers received one drop into each eye of T1225 0.5% (n=23), T1225 1.0% (n=38), or T1225 1.5% (n=38). Azithromycin tear concentrations were measured by HPLC-MS at seven time points for 24 hours. Tolerability was evaluated. RESULTS: T1225 1.0% and 1.5% had similar pharmacokinetic profiles. After a post-instillation peak (167 to 178 mg/L after 10 minutes), mean concentrations remained above 7 mg/L for 24 hours (except for T1225 1% at H24). A delayed increase of the azithromycin mean tear concentration might be explained by the known late azithromycin release from tissues after storage in cells. Areas under inhibitory curve (AUICs) of T1225 1.0% and 1.5% were higher than AUICs of T1225 0.5% and ranged between 47 and 90. The three T1225 concentrations were safe for the ocular surface. CONCLUSIONS: Once daily instillation of T1225 1.0% and 1.5% was shown to reach an AUIC markedly above the required threshold for an antibacterial activity against Gram-positive bacteria (25-35). These results suggest that a BID instillation is more likely to ensure antimicrobial activity against Gram-negative bacteria (threshold >100).

Report on the 13th International Society of Blood Transfusion Platelet Immunology Workshop.

BACKGROUND AND OBJECTIVES: The aim of the 13th International Society of Blood Transfusion Platelet Immunology Workshop was to compare the sensitivity and specificity of the in-house method for the detection of human platelet antigen (HPA) antibodies currently used in participating laboratories with a modified rapid protocol for the monoclonal antibody (mAb) immobilization of platelet antigen (MR-MAIPA) assay. MATERIALS AND METHODS: Twenty-eight laboratories from 15 countries participated. A set of four freeze-dried minimum potency reference reagents with known single-specificity HPA antibodies were supplied for testing by titration with both assays and two coded freeze-dried plasma samples were provided for antibody specificity testing. Critical reagents and materials for the MR-MAIPA were provided including lyophilized panel platelets and five capture mAbs. RESULTS: Titration of the reference standards showed that the sensitivity of the MR-MAIPA was the same as the in-house methods. The proposed replacement anti-HPA-1a reference reagent 05/106 gave results that did not differ significantly from the current reference reagent 93/710. The results with the two blinded samples showed that in the first sample, 27 out of the 28 laboratories were able to correctly identify the anti-HPA-1a present when using their respective in-house methods, but only 23 correctly identified the antibody when using the rapid MAIPA method. The results from the second sample, which contained multispecificities, showed that only 50% of the participants correctly identified all five antibodies present using their in-house method. The results for the rapid MAIPA were lower, with only 32% identifying all specificities. The variability in the reconstitution of the freeze-dried platelets may have been one of the contributing factors to the poorer results. CONCLUSIONS: The sensitivity of the MR-MAIPA compared favourably with that of the in-house methods. Most laboratories were able to identify anti-HPA-1a alone in Sample 1 but more than half of the participants were not able to correctly assign the specificity of all HPA antibodies present in the second sample. The usefulness of the panel of freeze-dried platelets varied considerably between laboratories.

Severe HPA-15b related neonatal alloimmune thrombocytopenia.

UNLABELLED: The HPA-15 platelet (PLT) group was recently described. Severe neonatal thrombocytopenia due to alloimmunization by HPA-15b has very rarely been observed. A 22-year-old mother, gravida 1/para 1, gave birth to a male infant who presented with a severe thrombocytopenia, the PLT count recorded to be 3 x10(9)/L. A few hours after birth, he developed purpura with extensive haematomas but without visceral or intracranial haemorrhage (ICH). Two PLT transfusions were given including one using maternal PLTs. The infant's PLT count was 267 x 10(9)/L on day 6. The maternal platelet group was HPA-15a/a and her infant was HPA-15a/b. Anti-HPA-15b antibodies was found in maternal serum. CONCLUSION: HPA-15b maternal alloimmunization may induce severe neonatal thrombocytopenia. In order to establish the frequency of neonatal alloimmune thrombocytopenia (NAIT) due to anti-HPA-15b antibodies, an improved detection method is necessary.

IgA anti-red blood cell auto-antibodies in Evans syndrome.

In Evans syndrome, IgG auto-antibodies (Abs) and/or complement components are frequently detected on red blood cells (RBC) in the direct antiglobulin test (DAT). A 70-year-old man with Evans syndrome diagnosed four years previously presented with a persistent autoimmune haemolytic anaemia, despite immunosuppressive treatment and normalization of platelet count. The RBC allo- and auto-Abs screening and identification were performed by indirect antiglobulin test (IAT) and DAT. In March 2006, no circulating anti-RBC auto-Abs were found in IAT but the DAT was positive with anti-IgG (++), -C3d (weak) and -IgA (++). Follow up for 11 months revealed anti-RBC IgA auto-Abs on five out of six samples. IAT was positive for RBC auto-Abs on three samples. No correlation between the haemoglobin level and the strength of reactivity of IgG and IgA auto-Abs was observed. IgA anti-RBC auto-Abs are present in Evans syndrome. To detect these Abs and characterize their role, DAT procedures should systematically include anti-IgA.

[Intravenous human immunoglobulin treatment for neonatal alloimmune thrombocytopenia due to anti-HPA-5b with severe previous history]. / Traitement par immunoglobulines intraveineuses dans 2 cas d'allo-immunisation foetomaternelle plaquettaire HPA-5b avec antécédents sévères.

Fetal and neonatal alloimmune thrombocytopenia due to mothers' anti-HPA-5b alloimmunization has generally a milder clinical presentation compared to anti-HPA-1a alloimmunization. Nevertheless, a case with infant's death probably due to intracranial haemorrhage has been reported. However, if platelet-specific alloimmunized mothers with prior fetal or neonate injury receive intravenous immunoglobulins during pregnancy, thrombocytopenia in heterozygous fetus and neonate may be prevented. Here are reported 2 cases of anti-HPA-5b fetal-maternal alloimmunization, one with prior fetal death, the other with prior severe fetal intracranial haemorrhage, which were successfully treated with intraveinous immunoglobulins alone during a second pregnancy with HPA-5b incompatibility.

Adaptability of protein A-immunoadsorption allows temporary reduction of anti-VIII antibodies and realisation of high-risk haemorrhagic surgery.

We report the successful treatment by protein A-immunoadsorption (IA) of an hemophilic man with anti-F VIII antibodies (Abs) who needed high-risk bleeding surgery. This patient had developed high levels of anti-F VIII Abs preventing substitution by clotting factor and preventing high-risk bleeding surgery. Because of rebound in Abs levels or complications, IA procedures were modified several times leading to appropriate decrease of anti-F VIII inhibitor Abs allowing bilateral knees surgery. IA procedure is enough adaptable to be modified to prevent complications. Collaboration between clinical, biological, apheresis and surgical teams implied has permitted surgery and prevented life-threatening bleeding complications.

Alloreaction increases or restores CD40, CD54, and/or HLA molecule expression in acute myelogenous leukemia blasts, through secretion of inflammatory cytokines: Dominant role for TNFbeta, in concert with IFNgamma.

We have previously reported that alloreaction can lead to activation of dendritic cells through secretion of inflammatory cytokines. Here, we addressed whether alloreaction-derived cytokines may also lead to acute myelogenous leukemia (AML) blast differentiation. With this aim, supernatant (sn) harvested from major or minor histocompatibility antigen-mismatched mixed lymphocyte reaction (MLR) were used to culture French American Bristish (FAB) type M4 or M5 AML blasts. Our results showed that the secreted factors induced upregulation of CD40, CD54, and/or HLA molecules in AML blasts. Protein fractionation, blockade experiments and exogenous cytokine reconstitution demonstrated the involvement of TNF in the upregulation of CD54, CD40 and HLA-class II molecules, and of IFNgamma in the increase of HLA-class I and class II molecule expression. But, in line of its much higher levels of secretion, TNFbeta, rather than TNFalpha, was likely to play a preponderant role in AML blast differentiation. Moreover TNFbeta and IFNgamma were also likely to be involved in the AML blast differentiation-mediated by HLA-identical donor T-cell alloresponse against recipient AML blasts. In conclusion, we show herein that upon allogeneic reaction, TNFbeta secretion contributes, in concert with IFNgamma, to increase or restore surface molecules involved in AML blast interaction with T cells.