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To detect and quantify by flow cytometry (FC) PNH clones in paroxysmal nocturnal haemoglobinuria (PNH) and aplastic anaemia (AA) patients.We have performed a flow cytometric analysis to determine the granulocyte expression of CD55 and CD59 from 29 patients with AA and 11 patients with PNH.In the 11 PNH patients the study showed 58 +/- 34% and 56 +/- 32% (mean +/- SD) CD55(-) y CD59(-) granulocytes. A good correlation was found between the results of FC and haemolysis. The follow-up study showed PNH clone progression in one case and stability in 5 cases. Among 11 AA patients studied at diagnosis, two presented a population of CD55(-) granulocytes (14% and 48%) with CD59 normal, this defect disappeared in both patients after immunosuppressive therapy. The FC study revealed PNH clones in 7 cases among the 26 analyzed after treatment (23 with ATG and/or CyA), in 3 cases with negative Ham's test (in two this became positive 6 and 12 months later). The mean values obtained in these 7 patients with PNH-AA syndrome were 26 +/- 15% y 36 +/- 30% (mean +/- SD) CD55(-) and CD59(-) granulocytes. The median time from diagnosis to detection of PNH phenomenon was 83 months. In the follow-up study, 4 cases had stability, one case had a decrease and one a progression of the abnormal clone. In a retrospective analysis, among the 7 patients with PNH-AA syndrome, 5 had a partial response after the initial treatment.The FC on granulocytes is a useful method to diagnose and characterize PNH. This test is good for early detection of PNH clones in AA patients at initial diagnosis and in long term survivors. In both diseases it permits measuring the extent of the abnormal clone and its follow up. The extent of the defect is more related to haemolysis than the haematopoietic deficiency. PNH development seems to be more frequent in AA patients with incomplete response after immunosuppressive therapy and in some cases the defect could be latent at the time of diagnosis.

Mucormycosis is becoming recognized as a serious complication in patients undergoing hemopoietic transplantation (HT), because it is a major cause of morbidity and mortality. In our institution 4 cases of mucormycosis in post-HT period among 345 patients undergoing HT were diagnosed between 1984 and 1997. We studies the clinical characteristics of these cases and we conclude that mucormycosis is not a common infection in patients undergoing HT but that it is followed by a high morbidity and mortality. Maintained neutropenia is the most important risk factor.

An asymptomatic 26-year-old woman with mild macrocytic anemia (11.6 g Hb/dl) was studied. All biochemical parameters, bone marrow histology and cytogenetics were normal. The Ham's and sucrose tests were negative. A flow cytometric analysis revealed that CD55 and CD59 staining was absent in 20% and 21% of the granulocytes, but erythrocytes and CD34-positive bone marrow cells were CD55 and CD59 positive. Seven months after the initial study, the patient suffered an episode of hemoglobinuria, with mild anemia, moderate thrombocytopenia and a weak positive sucrose lysis test. A new flow cytometric analysis disclosed an increased percentage of CD55 and CD59 negative granulocytes and a 25% of erythrocytes with an intermediate pattern of fluorescence after CD59 labelling. At fourteen months, a population of CD55-deficient erythrocytes was detected and the Ham's test became positive. The present report is, to our knowledge, the first case of smoldering paroxysmal nocturnal hemoglobinuria in a patient with no previous aplastic anemia, or evident pancytopenia. The diagnosis was established by flow cytometry of peripheral blood granulocytes, with apparently phenotipically normal progenitor cells in an early stage of the disease. Flow cytometry appears to be a useful tool in our knowledge of paroxysmal nocturnal hemoglobinuria evolution.

To evaluate the ITP treatment modalities and their results in a series of 30 adult patients.30 patients, age 15-74, were diagnosed of ITP in our institution between 1988 and December 1991. We defined the ITP as: mild (plateletsor = 50 x 10(9)/L andor = 120 x 10(9)/L), moderate (platelets 25-50 x 10(9)/L) and severe (plateletsor = 25 x 10(9)/L). Treatment was initiated when the platelet count reached a level50 x 10(9)/L. Initial therapy was oral prednisone or methyl-prednisolone in all patients. In 12 unresponsive patients the treatment included splenectomy. Patients who fail steroid therapy and splenectomy received additional lines of therapy, that included: vincristine (n = 2), vinblastine (n = 1), danazol (n = 5), anti D immunoglobulin (n = 6), methotrexate (n = 2), intravenous immunoglobulin (n = 3).Complete remission was obtained in 19 patients with a follow-up of 3 to 55 months (median, 30 months). Partial remission was achieved in 4 patients, that was sustained for 9 to 39 months (median, 22.5 months) after initial therapy. One unresponsive patient died of infection. Six mild ITP patients did not require therapy with a follow-up of 14 to 56 months (median, 33.1 months).In adult patients with mild ITP, therapy is not required. Steroid therapy remains the initial therapeutic choice for moderate and severe ITP. In unresponsive patients useful alternative choices are splenectomy, danazol, anti D immunoglobulin and methotrexate.

AUTOIMMUNE DISEASES (AD) have a high prevalence and cause significant morbidity, health care expense, and mortality. The treatment of certain patients suffering from severe AD, refractory to conventional therapies, is unsatisfactory. Theoretical considerations, preclinical animal models, and recently published clinical experience support the concept that the natural course of AD may be altered by intensive immunoablation and autologous stem cell transplantation (ASCT). Eradication of autoreactive cells by the conditioning regimen and redistribution of an altered cellular and humoral immunological network, or thymic reeducation, are potential mechanisms for response. On this basis, ASCT is a promising experimental therapy for AD resistant to conventional treatments. We report the preliminary results of the Spanish experience in this field.