[Study of 206 transfused sickle cell disease patients: immunization, transfusion safety and red blood cell supply]. / Etude d'une cohorte de 206 patients drépanocytaires adultes transfusés: immunisation, risque transfusionnel et ressources en concentrés globulaires.

BACKGROUND: Prevention of hemolytic transfusion reactions depends upon our capacity to prevent allo-immunization and conflicts between antigens of transfused red blood cells and antibodies produced by the recipient. In this study, we show that to secure transfusion of sickle cell disease patients, it is necessary to take into account their immunohematologic characteristics in the organization of transfusion. METHODS AND RESULTS: Immunohematological data of 206 chronically transfused patients have been collected as well as phenotypes of transfused units. In order to prevent allo-immunization against C and E antigens for patients typed D+C-E-c+e+ (56%), 26% of the transfused units were D-C-E-c+e+. We found that 47% of the patients had a history of allo-immunization, whereas only 15% produced an antibody the day of inclusion in the study. The non-detectable antibodies were frequently known as dangerous for transfusion. Finally, this study shows the frequency of anti-D in D+ patients and anti-C in C+ patients, pointing out the question of partial antigens. CONCLUSION: To insure optimal transfusion safety for sickle cell disease patients, three points have to be improved: blood donation within the Afro-Caribbean community living in France, access to history of immuno-hematological data, detection of variant antigens, especially within the RH blood system.

[ABO incompatibility and non myeloablative allogeneic stem cell transplantation]. / Incompatibilité ABO et greffe allogénique de cellules souches hématopoïétiques à l'ère des conditionnements non myéloablatifs.

ABO incompatibility is not a barrier for allogeneic hematopoietic stem cell transplantation but is associated with specific complications. Major ABO incompatibility is associated with delayed erythroid engraftment, increased transfusion requirement and cases of pure red cell aplasia. Minor ABO incompatibility may be responsible for acute haemolytic reactions in the first months following transplantation. The widely used non myeloablative conditioning regimens might modify the management of ABO incompatibility. They could favour pure red cell aplasia development in the setting of major ABO mismatch since they are associated with a prolonged persistence of host anti-donor isohemagglutinins after allogeneic hematopoietic stem cell transplantation. In the setting of minor ABO incompatibility, the use of peripheral blood stem cells and the nature of graft-versus-host disease prophylaxis regimen may have an impact on the incidence of haemolytic reactions. In that review, the clinical and therapeutic aspects of ABO incompatibility are studied, especially regarding the impact of the conditioning regimen intensity.

Impact of nonmyeloablative conditioning regimens on the occurrence of pure red cell aplasia after ABO-incompatible allogeneic haematopoietic stem cell transplantation.

BACKGROUND AND OBJECTIVES: In the setting of major ABO-incompatible allogeneic haematopoietic stem cell transplantation (HSCT), pure red cell aplasia (PRCA) is linked to the persistence of host residual plasma cells secreting antidonor isohaemagglutinins (HA) after transplantation. There are conflicting results regarding the impact of the intensity of conditioning regimen on the occurrence of PRCA after major ABO-mismatched HSCT. MATERIAL AND METHODS: To address this question, we compared two cases occurring after nonmyeloablative (NMA) and myeloablative (MA) HSCT and reviewed previous cases reported in the NMA setting. RESULTS AND CONCLUSIONS: We observed a delayed disappearance of antidonor HAs in the NMA setting, associated to a more prolonged period of red blood cells transfusion dependence than in the MA setting. In our case as in several others, the disappearance of antidonor HAs and resolution of PRCA were observed after reinforcement of the graft-versus-host effect (i.e. immunosuppression removal or donor leukocytes infusion).

Do minitransplants have minicosts? A cost comparison between myeloablative and nonmyeloablative allogeneic stem cell transplant in patients with acute myeloid leukemia.

Allogeneic hematopoietic stem cell transplantation (SCT) is a widely used, cost-intensive procedure. Although pretransplant nonmyeloablative (NMA) or reduced-intensity conditioning regimens appear very promising, prospective studies comparing this approach with the conventional myeloablative (MA) approach in specific hematologic diseases are necessary, especially in patients in whom the conventional approach is not contraindicated. Cost may be an important factor in the decision-making process. We compared the costs of MA and NMA transplants in patients with acute myeloid leukemia (AML). We estimated 1-year resource utilization in 12 consecutive MA patients (median age: 39 years) and in 11 consecutive NMA patients (median age: 58 years) who underwent HLA-identical sibling SCT for AML. Resources care expenses were valued using the average daily rate for personnel costs, supplies, and room costs. Other data were directly collected from the patients' charts. Despite a trend for lower costs in NMA patients during the first 6 months, costs during the 6-12-month period were significantly higher after NMA due to late complications and readmissions (P=0.03). Finally, mean 1-year costs were not different in MA and NMA patients (P=0.75). Prospective studies comparing conventional and NMA approaches in homogeneous populations should include economic items.

Brb, a platelet alloantigen involved in neonatal alloimmune thrombocytopenia.

Serum from a pregnant woman with the May-Hegglin anomaly contained a platelet-specific antibody. The serum reacted in the platelet indirect immunofluorescence test (PIIFT) with 97.6% of random donor platelets and those of the father but not with the mother's own platelets. This antibody induced a moderate thrombocytopenia in the infant that responded to infusion of intravenous immunoglobulin concentrates. The platelet phenotypes were PLA1+, Baka+, Bra+/Brb- for the mother, PLA1+, Baka+, Bra-/Brb+ for the father, and PLA1+, Bra+/Brb+ for the neonate. Analysis of the maternal serum with an immunoassay based on monoclonal antibody immobilization of platelet antigens (MAIPA) and immunoprecipitation techniques demonstrated the absence of antibodies directed against HLA class I antigens and that the antigen recognized was located on the platelet-GpIa/IIa complex. This antigen was present on 113/115 random donor platelets, in 7 of the 7 unrelated May-Hegglin platelets, and only absent in 3/24 Bra+ individuals, including the mother. No platelet-specific antibody was present in the serum of the 7 unrelated May-Hegglin subjects. The antigen recognized by this platelet-specific antibody thus meets the criteria defining the antithetic allele of Bra, i.e. the Brb alloantigen.

[Transfusion strategy for patients in therapeutic aplasia. Experience of the Henri Mondor Hospital apropos of 2 successive protocols]. / Stratégie transfusionnelle pour les malades en aplasie thérapeutique. Expérience de l'Hôpital Henri Mondor à propos de 2 protocoles successifs.

Retrospective analysis of two transfusion protocols applied in our institution to the bone marrow transplanted patients was conducted. Granulocyte transfusions should be only proposed as a therapeutic treatment to patients with severe well documented bacterial infection resistant to an adapted antibiotherapy. Leukocyte-depleted blood products reduce the incidence of HLA-immunization but do not influence the frequency of CMV infections. Random single donor platelet concentrates (obtained by cytapheresis) could decrease the incidence of polyspecific HLA-antibodies in comparison with the use of random standard platelet concentrates. The best transfusion protocol should associate leukocyte-depleted blood products with transfusion of prophylactic single donor platelet concentrates. In our institution, this protocol is less expensive than the protocol with prophylactic white blood cell transfusions and has the same cost than other protocols using standard blood products.

Acquired autoimmune thrombocytopenia after allogeneic bone marrow transplantation.

A 29-year-old man in remission from acute myeloblastic leukaemia was treated by chemoradiotherapy and transplantation of bone marrow (BMT) collected from his HLA identical brother. Engraftment was documented on D12. Transient acute GVHD (grade II) appeared from D34. No infection complicated the BMT. Nevertheless severe thrombocytopenia persisted and was unresponsive to marrow donor platelet transfusion. The platelet immunofluorescence test demonstrated the autoimmune basis of the thrombocytopenia. This study suggests that the transient immune imbalance observed in the early post graft period could facilitate the appearance of autoimmune cytopenias.

Acute promyelocytic leukemia in 57 previously untreated patients.

Fifty-seven patients in initial phase of acute promyelocytic leukemia (APL) were treated in the same department with heparin infusion, platelet transfusions, and two related induction regimens both including cytosine arabinoside and daunorubicin. Clinical and biological findings at presentation were studied. The complete remission (CR) rate was 53%. Twenty-seven patients (47%) died during the initial course of the disease, either before day 5 (early death [ED], n = 7) or after day 5 (death in aplasia [DA], n = 20). Most ED was due to intracerebral hemorrhage (6/7), especially when large hemorrhages had been seen on fundus oculi examination. Most DA was due to multivisceral failure (9/20). No correlation was found between initial disseminated intravascular coagulation (DIC) and death. However, the worsening of coagulation parameters during induction therapy, with or without initial DIC, significantly increased the occurrence of renal and respiratory failure which were particularly frequent during the first month. The median duration of survival was short (3.5 months) and the median duration of CR (11 months) was similar to that of other acute myeloid leukemias treated with the same regimens. The possible causes of the high mortality observed during the initial courses of APL and the possible benefit of a more graduate induction chemotherapy are discussed.

High dose intravenous gammaglobulin and platelet transfusions in leukaemic HLA-immunized patients.

3 aplastic patients with acute leukaemia, strongly HLA-immunized and refractory to platelet transfusions, received polyvalent gammaglobulin i.v. infusions (0.4 g/kg/d for 5 or 6 d) in association with daily random platelet transfusions. Platelet recovery was obtained in 2 patients. The 3rd patient did not show any significant rise in platelet count. The ability of gammaglobulin to prolong the life-span of incompatible transfused platelets could facilitate the management of HLA-immunized patients.

Cytomegalovirus encephalitis occurring after bone marrow transplantation.

4 months after a bone marrow transplantation performed for acute lymphocytic leukaemia, a 28-year-old man had encephalitis. A brain CT scan revealed bilateral and symmetrical temporal hypodense areas. Serological studies revealed a recent CMV conversion in serum and a higher conversion in cerebral spinal fluid. All other viral antibodies remained at low levels, especially for herpes simplex virus. Because of a high incidence of CMV infection after bone marrow transplantation, the responsibility of CMV as the cause of the encephalitis is discussed.

Successful allogeneic bone marrow transplantation after reversion of chronic phase of blast crisis in chronic myeloid leukemia.

A female with chronic myeloid leukemia (XX Ph 1 +) in blast crisis (localized to pleura and lymph nodes) was treated by polychemotherapy. After reversion to the chronic phase, and allogeneic bone marrow transplantation, (BMT) was performed. Sixteen months after BMT, no sign of the disease was present (XY Ph 1-).