Positive selection of CD34+ cells from cryopreserved peripheral blood stem cells after thawing: technical aspects and clinical use.

Autologous stem cell transplantation has become an important therapy in lymphoma, multiple myeloma and solid tumors. The rationale for the selection of CD34+ cells from peripheral blood or bone marrow progenitor cell collections is based on the observation that contaminating tumor cells can be depleted approximately 3 to 6 logs. This procedure may be limited because of lack of sufficient numbers of progenitor cells in the leukapheresis concentrates. The use of frozen/thawed peripheral blood mononuclear cell (PBMC) samples makes it possible to pool two or even more stem cell harvests collected at different time points to increase the total number of CD34+ progenitor cells. We report in this work the feasibility of frozen/thawed peripheral blood CD34+ positive cell selection, using the large-scale (Ceprate SC) and the lab-scale avidin-biotin immunoadsorption system (Ceprate LC). This procedure consists of a washing step and a positive selection step. Our results show that frozen/thawed CD34+ cells were obtained with a purity of 86.68 +/- 3.62%, a viability of 97.94 +/- 0.97% and a recovery of 91.85 +/- 10.84% (range 80 to 112%). The CFU-GM assays were performed in a methylcellulose based medium; 89.13 +/- 19.63 colonies were obtained for 10(3) cells plated. Two patients were grafted with peripheral blood CD34+ cells selected after freezing. Our clinical data show that these cells are capable of rapidly reconstituting hematopoiesis after high-dose chemotherapy.

Emergence of unusual cytogenetic abnormalities under interferon-alpha therapy in patients with chronic myelogenous leukemia.

New treatments that may change the course of a disease or have potential carcinogenicity can result in the emergence of new cytogenetic or clinical disorders. We report here the cytogenetic evolution of 52 cases of Philadelphia (Ph)-positive myelogenous leukemia (CML) receiving interferon-alpha (IFN-alpha) therapy compared with that of 59 Ph-positive CML cases treated with busulfan (BU) or hydroxyurea (HY). Twenty-one percent of the CML patients receiving IFN-alpha displayed unusual secondary abnormalities, among which alteration of the long arm of chromosome 3, del(7), and del(9) were recurrent. The frequency of these unusual secondary changes was significantly higher than in CML cases after Bu or Hy treatment (P = 0.02). Three of the 11 IFN-alpha-treated CML patients displayed cytogenetic evolution in the chronic phase and, in two cases, the cytogenetic findings were transient, inasmuch as they disappeared upon withdrawal of IFN-alpha. In addition, a majority of cytogenetic abnormalities involved chromosome 3 at bands 3q21 and 3q26, which corresponds to the locus of EVI1, a gene implicated in the development or progression of human myeloid leukemias. Possible explanations include: toxicity of IFN-alpha by effect on bone marrow stroma, immune-modulating effects of IFN-alpha, and mutagenic effects of IFN-alpha. The mechanisms underlying these cytogenetic changes remain to be elucidated. However, our data suggest that IFN-alpha induces additional cytogenetic abnormalities even in the chronic phase through its immune-modulating effects and that these unusual cytogenetic abnormalities do not alter the history of CML.

[Occurrence of severe, persistent thrombocytopenia following allogeneic bone marrow transplantation, attributable to anti-HPA-1 allo-immunisation of the host]. / Survenue d'une thrombopénie sévère et durable, au décours d'une greffe de moelle allogénique, imputable à l'existence chez l'hôte d'une allo-immunisation anti-HPA-1.

A 56 year-old, multiparous woman suffering from a myeloproliferative syndrome, who had received multiple red blood cell and platelet transfusions, was the recipient of an allograft of peripheral blood stem cells derived from her HLA-A, B, DR, DQ and DP and ABO identical sister, following myeloablative conditioning. The persistence of severe, isolated thrombopenia resistant to platelet transfusions led to the discovery of anti-HLA class I allo-immunisation. As HLA compatible platelet transfusions did not result in satisfactory platelet increments, we then discovered the simultaneous presence of anti-HPA-1a allo-immunisation. Genotyping of the HPA-1 systems of the patient (HPA-1B/B) and her sister (HPA-1A/B) enabled us to elucidate the mechanism underlying the persistent thrombopenia and the inefficacy of transfusion. In fact, only transfusion of HPA-1B/B platelets (HLA compatible or incompatible) proved to be efficacious. To reduce the level of anti-HPA-1a antibodies, we performed plasmapheresis sessions and used an anti-CD20 monoclonal antibody. It was only on achieving total haematopoietic chimerism, through rapid interruption of the immunosuppression, that we obtained spontaneous normalisation of the platelet count. The present case emphasises the necessity, before undertaking any allograft of haematopoietic stem cells - even if the latter come from a strictly HLA identical member of the family - of performing a search for eventual anti-HPA allo-immunisation.

Heridas y traumatismos del torax. / Wounds and injuries of the thorax

Se analizan 460 pacientes que sufrieron heridas y traumatismos toracicos entre 1972-1981. Se trataba en la mayoria de adultos jovenes (11 a 40 anos) del sexo masculino 9/1. Predominaron las heridas penetrantes por arma blanca y de fuego (85,22%) sobre los traumas cerrados (14,78%). El diagnostico se establecio por la anamnesis, el examen fisico, la radiologia del torax y la estimacion de la volemia. La hemorragia intrapleural fue mas importante en las heridas por arma blanca y de fuego (de 600 a 900ml).La ruptura del diafragma se aprecio en 1/3 de los pacientes (32%), las heridas del corazon en el 7,07%, las del pericardio en el 10,62%, de vasos intercostales en el 8,56%; y de la mamaria interna en el 7,64% y las del pulmon en el 18,24%. Las fracturas costales se presentaron en el 49,97% En la patologia asociada las lesiones mas frecuentes fueron las abdominales que requirieron exploracion en el 18,53%.Fueron tratados con toracotomia inmediata el 42,40% y con tubo de drenaje el 43,05%.Las complicaciones mas importantes fueron: infeccion de la herida toracica (14,31%), de la herida abdominal (11,30%) y fistulas broncopleurales (11,11%). El promedio de internacion fue 7,28 dias