Microangiopatias trombóticas: SUH/PTT. Aspectos fisiopatológicos. / [Thrombotic microangiopathies: HUS/TTP. Physiopathological aspects]

In thrombotic thrombocytopenic purpura (TTP) and in the hemolytic uremic syndrome (HUS) fibrin-platelet thrombi occlude arterioles and capillaries. The mechanism of endothelial cell injury and the mechanism of thrombosis are the most important physiopathological events in this pathology and are largely unknown. In HUS due to the Shiga toxin, the lesion of the endothelial cells is due to penetration of the toxin into the cell via the Gb3 receptor. Endothelial cell death is a consequence of altered protein synthesis at the ribosomal level. Cytokines released during the inflammatory process, possibly enhance the endothelial damage. Genetic and immunologic predisposing factors for the development of HUS have also been postulated. In idiopathic, secondary and familial HUS/TTP the mechanism of endothelial lesion is unknown, but multiple responsible factors have been advocated such as infections, drugs, pregnancy, autoantibodies, apoptosis inducing molecules, etc. and other genetic, hormonal or immunologic predisposing factors may also be involved. Factor H deficiency has been blamed in familiar cases. The most important cause of microcirculation thrombosis is the thrombogenic capacity of endothelial cell [quot ]activation[quot ] or injury induced by multiple mechanisms. The predominant source of plasma vW factor multimers is apparent in the altered endothelial cell. The unusually large vWF multimers are more effective at binding to platelet glycoprotein Ib-IX and IIb-IIIa complexes and inducing aggregation, as also occurred with the low weight multimers formed with excessive proteolysis, as described in the acute phase of HUS/TTP. The recent report of congenital deficiency of a vWF protease in familial TTP and its functional inhibition by autoantibodies in acquired cases is characteristic of TTP. This protease inhibition has never been described in HUS and might represent pathogenetic differences between TTP and HUS, and contribute to the differential diagnosis, but further confirmation of these findings is needed. We postulate that the abnormal cleavage of the vWF subunit, with formation of different multimers with increased platelet aggregating capacity is an important mechanism to increase the microcirculatory thrombosis, but it is only a partial aspect in a more complex and unknown thrombogenic stimulation secondary to the endothelial lesion or activation. Better knowledge of the endothelial physiology and the genetic polymorphism of the endothelial cell, the clonation of vWF-cleavage protease, etc., will provide valuable tools for the understanding of these fascinating entities.

Neoplasias hematológicas y embarazo. / [Hematologic neoplasms and pregnancy]

Hematologic neoplasms diagnosed during pregnancy, present significant difficulties in patient management. Besides the strictly medical facts, moral, ethical and religious issues should be strongly considered. For the optimal management of individual situations an integrated multidisciplinary approach is mandatory. Hodgkins disease, acute leukemias, non Hodgkins lymphoma and less frequently chronic myelogenous leukemia have been reported in pregnant women. Curative treatment for most of these diseases include intensive chemotherapy regimens. Potential damage to the fetus is a major concern, due to the teratogenic effects of antimetabolites, alkylating agents and radiation therapy. Effect of pregnancy in each of these neoplasms is discussed. Although some rules of management exist, dangerous generalizations should be avoided. Particular obstetric considerations such as timing of delivery, and therapeutic abortion should be carried out on an individual basis. The emotional impact of the situation must not be underestimated.

Tuberculosis en pacientes con linfomas. / [Tuberculosis in patients with lymphomas]

In a period of ten years (1980-1989) 6 patients, out of 506 cases of lymphoma, presented an active tuberculosis (1.18

). Five of them had Hodgkin disease in an advanced stage, with predominance of the nodular sclerosis histologic subtype; one had a non Hodgkin lymphoma. Clinical presentation of TBC was mostly focal with a predominance of extra pulmonary involvement (cervical tuberculous lymphadenitis); disseminated disease only appeared in the non Hodgkin lymphoma patient. There was no difference in the severity of the infection when it appeared either before or after multiagent therapy of the hematologic malignancy. There was clinical suspicion of TBC in all of the pulmonary forms of the disease; lymph node tuberculosis, without drainage of caseous material, was a finding related to the routine culture of lymphatic tissue. In biopsy material, in which Mycobacterium tuberculosis was isolated, neither epithelioid cell granulomas with caseation necrosis nor acid-fast bacilli were histopathologically documented. No mortality due to tuberculous infection was registered in this group. TBC prevalence in these lymphoma patients was 1185.7 per 100,000; compared with the prevalence of this disease in the general population (52.3 per 100,000) a significant difference is demonstrated (p < 0.0001) and it is related to Hodgkin lymphoma.

Tuberculosis en pacientes con linfomas. / [Tuberculosis in patients with lymphomas]

In a period of ten years (1980-1989) 6 patients, out of 506 cases of lymphoma, presented an active tuberculosis (1.18

). Five of them had Hodgkin disease in an advanced stage, with predominance of the nodular sclerosis histologic subtype; one had a non Hodgkin lymphoma. Clinical presentation of TBC was mostly focal with a predominance of extra pulmonary involvement (cervical tuberculous lymphadenitis); disseminated disease only appeared in the non Hodgkin lymphoma patient. There was no difference in the severity of the infection when it appeared either before or after multiagent therapy of the hematologic malignancy. There was clinical suspicion of TBC in all of the pulmonary forms of the disease; lymph node tuberculosis, without drainage of caseous material, was a finding related to the routine culture of lymphatic tissue. In biopsy material, in which Mycobacterium tuberculosis was isolated, neither epithelioid cell granulomas with caseation necrosis nor acid-fast bacilli were histopathologically documented. No mortality due to tuberculous infection was registered in this group. TBC prevalence in these lymphoma patients was 1185.7 per 100,000; compared with the prevalence of this disease in the general population (52.3 per 100,000) a significant difference is demonstrated (p < 0.0001) and it is related to Hodgkin lymphoma.

Infecciones afebriles en pacientes adultos con leucemia aguda. / [Afebrile infections in adult patients with acute leukemia]

Characteristics of afebrile infection episodes among adult patients with acute leukemia are here described. Afebrile episodes represented 14.3

of all infections. They significantly differed from the febrile episodes because: 1) they prevailed among patients with granulocyte count greater than 500/mm3 (p < 0.001); 2) they often involved patients in complete remission (p < 0.0002); 3) they affected more frequently the kidney and urinary tract than febrile infections (p = 0.0005) and 4) they lacked lung involvement (p < 0.01). The rate of documented infections by cultures, cytology or serological tests was not different between both infection types. Observed mortality during afebrile episodes was threefold less than febrile infections; this difference, however, did not reach statistical significance. In conclusion, afebrile infection in acute leukemia is a distinct clinical entity, unlike febrile infection.

Receptores histamínicos H2, AMPc y diferenciación celular leucémica / H2 histaminics receptora, AMPc and leukemia celular diferenciation

Con el objeto de explorar su potencial empleo en terapéutica no citotóxicas, se estudió, en células leucémicas humanas, la vía de señalización y probable rol regulatorio del receptor a histamina H2. Mediante ensayos de binding, se detectaron sitios de unión específica de tipo H2, en casi todas las muestras de M.O.y S.P. de pacientes con L.A., con diferentes grados de infiltración. esto sugiere la presencia del receptor H2, en células hemopoyéticas normales y transformadas. La líneas U-937, modelo de célula monoblástica, presenta receptores H2, acoplados a AMPc. Su estímulo no produjo cambios proliferativos, ni deferenciación celular, pero sí un aumento transitorio, vía proteín kinasa A (PKA), en la expresión de Fos y Hun, sin reducción de Myc. Se hipotizó que el fracaso del estímulo H2, para diferenciar las células U-937 podría deberse a que su activación de la PKA es breve. Concordante con lo anterior, los receptores H2, mostraron una veloz de desensibilización homóloga (T. 1/2 = 20´). En cambio la forskolina, un activador directo de la adenil ciclasa, no desensibilizó su estímulo ni aún después de 24 horas de incubación. La forskolina también inhibió la proliferación U-937 a las mismas concentraciones en que estimuló la síntesisde AMPc e indujo su diferenciación fagocitaria, con reducción del NBT y respuesta quimiotáctica al C5a. Conclusiones: 1) La desensibilización veloz de un receptor que transduce una señal diferenciadora, como el H2, en las células U-937, podría ser un mecanismo fisiopatogénico de la malignificación, al bloquear la recepción de estímulos madurativos por la célula neoplásica. 2) Dados estos resultados, y los efectos diferenciadores del dibutril AMPc (DBAMPc) en líneas celulares mieloides, los agentes que elevan el AMPc merecen ser valorados en la terapia de las LMA (AU)

Profilaxis con fluoroquinolonas en pacientes neutropénicos / Prophylaxis with fluoroquinolones in patients with neutropenia

Para evaluar si el uso profiláctico de fluoroquinolona disminuye la incidencia y morbimortalidad de los episodios febriles durante la neutropenia, realizamos un estudio prospectivo, aleatorio y controlado en pacientes adultos con leucemia aguda (A.A.), con neutropenia secundaria a quimioterapia citotóxica y ambulatórios. Veinticinco episódios de neutropenia ocurridos en 14 pacientes fueron asignados aleatoriamente a recibir quinolonas (norfloxacina 800 mg/día o ciporfloxacina 1000 mg/dia), o a no recibir antibióticos profilácticos (grupo control). No hubo diferencias significativas entre ambos grupos en sexo, edad, tipo o estadio de la L.A., esquemas de quimioterapia empleados, duración y severidad de la neutropenia con fiebre (p = 0,0448), a una disminución del número de infecciones por bacilos gran negativos (p = 0,037), y a un aumento de las infecciones por Estreptococos (p = 0,0857). No hubo disminución significativa en la mortalidad, incidencia de infecciones severas, proporción de episodios de neutropenia sin fiebre, requerimiento de Anfotericina B, e incidencia de infecciones micóticas en el grupo con quinolonas respecto del control. Se concluye que la profilaxis con fluoroquinolonas no disminuyó la morbimortalidad infecciosa en estos pacientes (AU)

Profilaxis con fluoroquinolonas en pacientes neutropénicos. / [Prophylaxis with fluoroquinolones in patients with neutropenia]

In order to evaluate whether the prophylactic use of fluoroquinolones diminishes the incidence of infections and/or mortality during neutropenia, we undertook a prospective, aleatory and controlled study in non-hospitalized adult patients with acute leukemia and chemotherapy-induced neutropenia including twenty five episodes of neutropenia including twenty five episodes of neutropenia which had occurred in 14 patients who were randomly selected either to receive or not quinolones (norfloxacin 800 mg daily or ciprofloxacin 1000 mg daily). Both groups were similar in terms of sex, age, underlying disease, chemotherapy for hematologic malignancy, duration and severity of neutropenia. The use of quinolones was associated with a delay in the fever onset during neutropenia (p = 0.0448), a decrease in the proportion of neutropenic febrile days (p = 0.0456), a decrease of infections caused by gram-negative bacilli (p = 0.037) and an increase of Streptococcus infections (p = 0.0857). There was no significant decrease in mortality, incidence of severe infections, proportion of neutropenic episodes without fever, empiric use of amphotericin B or fungal infections between both groups. The results of this study demonstrate that the prophylactic use of fluoroquinolones does not diminish the infectious morbidity and/or mortality in these patients.

Tratamiento de la anemia en niños sometidos a hemodiálisis crónica con eritropoyetina humana recombinante. / [Treatment of anemia in children undergoing chronic hemodialysis with recombinant human erythropoietin]

Anemia associated to chronic renal failure (CRF) is a very frequent disorder. Twenty five per cent of adult patients under hemodialysis require periodical transfusions to maintain acceptable quality of life. This anemia is due mainly to a relative deficit of erythropoietin (EPO). Thanks to recombinant DNA techniques, EPO availability has made it possible to treat this population with the hormone. Most of the reported experience has been obtained from adult patients and literature on children is scarce. For this reason, a controlled prospective trial on 18 patients (9 males and 9 females) with a mean age of 12.4 years (range 7-17) was conducted, evaluating hematimetric response, safety of treatment and effect on quality of life after one year of treatment. Seventeen patients could be evaluated; mean follow-up was of 365 days (180-323). Treatment started with an administration scheme of 25 U/kg/dose, i.v. route, three times weekly, and dose was corrected according to the hematimetric response. Target hemoglobin was set in 10 g

. Mean dose required to reach target was 101.5 +/- 37.7 U/kg/dose (50-200) three times weekly and time elapsed was of 223.3 days (175-355). Only one patient did not achieve target hemoglobin value with the maximal dose planned (200 U/kg/dose). Bone marrow biopsy in this patient showed alpha widespread fibrosis secondary to hyperparathyroidism caused by CRF. Direct correlation was found between the required rHuEPO dose and basal levels of serum alkaline phosphatase (Table 2). Results obtained in status performance on six patients showed significant increase in all the variables under analysis (Table 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Tratamiento de la anemia en niños sometidos a hemodiálisis crónica con eritropoyetina humana recombinante / Treatment of anemia in children submitted to chronic hemodialysis with recombinant human erythropoietin

En la insuficiencia renal crónica (IRC), la anemia es una de las complicaciones más frecuentes, ésta es de tipo hipoproliferativo y su principal causa es el déficit relativo de eritropoyetina. El tratamiento fue, hasta la obtención de eritropoyetina por métodos recombinantes (rHuEpo), las transfusiones y los estimulantes eritropoyéticos, como los andrógenos. Actualmente existen muchas evidencias clínicas de la utilidad de la rHuEpo en el tratamiento de la anemia de la IRC. La mayoría de estos ensayos clínicos fueron realizados en adultos y en ellos se mostró no sólo la mejoría de los datos hematimétricos, sino también de la calidad de vida. Este trabajo se realizó en 18 pacientes pediátricos que estaban sometidos a regímenes de hemodiálisis crónica. El objetivo del mismo fue demostrar la seguridad y eficacia de la rHuEpo en los niños durante un año de tratamiento. El 94,2 por ciento de los pacientes evaluados alcanzaron la tasa de hemoglobina que habíamos planeado (10 gr por ciento), el único paciente que no lo logró tenía fibrosis medular. Los efectos adversos fueron similares a los observados en la población de adultos siendo la exacerbación de la hipertensión arterial el más frecuente. En seis niños se evaluó la capacidad física post tratamiento, todos se demosntró una mejoría de los índices de eficiencia. Se concluye que la rHuEpo es efectiva y segura en niños con IRC y anemia aumentando el número de glóbulos rojos evitando las transfusiones y mejorando el rendimiento físico que se relaciona con mejoría en la calidad de vida (AU)

Anemia hemolítica heteroinmune asociada a tratamiento con globulina antilinfocítica en un paciente con anemia aplástica. / [Heteroimmune hemolytic anemia associated with antilymphocyte globulin treatment in a patient with aplastic anemia]

A 24-year-old male patient with a severe aplastic anemia (SAA) was treated with equine-antilymphocyte globulin (ALG). As complication of this treatment he developed a severe heteroimmune hemolytic anemia mediated by anti-species pan-agglutinin antibodies present in ALG. In spite of the fact that ALG is absorbed with red-cell stroma and platelets to remove anti-erythrocyte and anti-platelet contaminating antibodies, often only partial absorption is achieved, and the remaining antibodies are passively acquired by the recipient. Neutropenia and especially thrombocytopenia are usual complications of this treatment, but it is also possible to detect anti-erythrocyte antibodies in the serum and on the red cells of those patients. However, the unusual severity of the hemolysis suffered by our patient, with a striking decrease of the hemoglobin levels (Fig. 1) can be ascribed to the administration of ALG at a time at which the hematocrit was close to normal as a result of the previous administration of anabolics. It is likely that in severely anemic patients, with a high transfusional demand, such a hemolytic episode may remain undetected. The patient acquired reactivity to the direct antiglobulin test, as well as the positive results of investigation of unexpected antibodies and compatibility testing can be accounted for by the fact that commercial antihuman globulin serum (AGS) contains antibodies reacting with a globulin component shared by human and horse sera. Neutralization of AGS with ALG administered to the patient removed those cross-reacting antibodies, making it possible to perform reliable transfusion compatibility testing and to rule out the eventual presence of hidden alloantibodies or warm autoantibodies. Neutralized Coombs serum maintained its human antiglobulin properties unaltered (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Aplicación de técnicas inmunocitoquímicas para el diagnóstico de neoplasias hematólogicas. / [Immunocytochemistry techniques for the diagnosis of hematologic neoplasms]

We studied 22 patients with hematological neoplasias which included: 12 patients with a diagnosis of Acute Myeloblastic Leukemia (AML) following the morphology and cytochemistry criteria established by FAB (French, American and British Committee), a Myeloblastic Leukemia secondary to MDS (Myelodysplastic Syndromes) and a biphenotypic acute leukemia where we established the relationship between the traditional peroxidase reaction with the anti-MPO by APAAP. We also carried out the nonspecific esterase reaction and determined the immunologic phenotype by FACS technology. The same procedure was used for the cellular analysis of the light chains kappa (kappa) and lambda (lambda) in 3 cases of hairy cell leukemia, one lymphoma and 4 cases of plasma cell neoplasia and reactive plasma cell disease. We conclude that immunocytochemical reactions must be used when morphology and traditional cytochemical reactions need to be confirmed in order to establish a correct diagnosis and this is specially important for B and T lymphomas. Their prognostic value is restricted and the results are useful as a complement to morphology, cytochemistry and immunological determinations.

Receptor soluble de transferrina y eritropoyetina en la anemia de los procesos crónicos con y sin deficiencia de hierro. / [Soluble transferrin receptor and erythropoietin in chronic disease anemia with or without iron deficiency]

The regulation of transferrin receptor (RTF) is related to intracellular iron stores and with the soluble receptor is present in plasma. It has already been demonstrated that in iron deficiency anemia (IDA), receptor expression increases when iron stores decrease. In anemia of chronic diseases (ACD) it is difficult to establish the real iron status because of the influence exerted by inflammatory or infectious diseases on iron metabolism. We studied 30 healthy normal subjects and 42 anemic patients (hemoglobin less than 120 g/L) affected with ACD divided into two groups with and without iron deficiency, in order to establish the diagnostic value of measuring the soluble transferrin receptor (sRTF). We correlated erythropoietin (EPO) (as an erythropoietic stimulating factor) with the decreased hemoglobin values observed in both groups. The results were analysed with an ANOVA statistic test of one way analysis of variance, and there were no significant differences in sRTF values between the ACD groups with or without iron deficiency. The ratio log EPO vs hemoglobin showed a remarkably significant inverse correlation in both groups. We can conclude that sRTF levels are within the normal reference values in these patients and are not related to organic iron. Consequently, sRTF cannot be considered a good parameter for making a diagnosis of iron deficiency in chronic diseases.

Tratamiento de la aplasia medular con globulina antilinfocitaria / Treatment of aplastic anemia with antilymphocyte globulin

Diez pacientes con diagnóstico de aplasia medular adquirida (AM) recibieron globulina antilinfocitaria (GAL) como tratamiento. Dos pacientes eran niños de dos yocho años de edad y el resto eran adultos con una media de 32 años (rango 16-56). El intervalo medio desde el diagnóstico hasta el inicio del tratamiento fue de 5,38 meses (rango 1-20. Cinco pacientes tenían antecedentes de contacto con benceno, organofosforado y piroxicam/ampicilina. Otro paciente tenía diagnóstico ce hemoglobinuria paroxística nocturna. En los cuatro restantes no se pudo determinar la etiología. Nueve pacientes habían recibido tratamiento previamente, seis con corticoides y andrógenos y res sólo con corticoides, sin respuesta. La GAL fue administrada bajo internación, en dosis de 10-20 mg/Kg/día durante cuatro días endos pacientes y en el resto durante ocho días. Entre el séptimo y el décimo día de comenzado el tratamiento, todos los pacientes desarrollaron enfermedad del suero, que fue controlada con prednisona. A los tres meses, tres pacientes tuvieron respuesta completa, y tres pacientes respuesta parcial. Cuatro pacientes no respondieron y de ellos tres fallecierom dos por sepsis y uno por hemorragia intracerebral. Nuestros resultados demuestran una respuesta completa o parcial en el 60% de los pacientes tratados con GAL, por lo que concluimos que la GAL es una opción terapéutica eficaz para el tratamiento de la AM severa o moderada en ausencia de posibilidad de transplante de médula ósea (AU)

Anemia hemolitica heteroinmune asociada a tratamiento con globulina antilinfocitica en un paciente con anemia aplastica / Heteroimmune hemolytic anemia associated with antilymphocyte globulin treatment in a patient with aplastic anemia

Se describe el caso de un paciente de 24 años de edad con anemia aplástica (AAS) tratada con globulina antilinfocítica (GAL) de origen equino, que desarrolla como complicación un grave cuadro de anemia hemolítica heteroinmune mediada por anticuerpos panaglutinantes anti-especie presentes en al GAL. La reactividad adqurida por el paciente en la prueba de Coombs directa, así como en la investigación de anticuerpos irregulares y en los tests de compatibilidad transfusional se explica por la existencia en el suero antiglobulina humana (SAGH) comercial de anticuerpos que reaccionan con un componente globulínico compartido por los sueros humanos y equino. La neutralización del SAGH con la propia GAL administrada al paciente removió esos anticuerpos de reacción cruzado, resultando de gran utilidad para poder llevar a cabo confiablemente la sprueba de compatibilidad transfusional y de detección de anticuerpos séricos (AU)

Fine needle aspiration for flow cytometry immunophenotyping of non Hodgkin lymphoma.

The aim was to evaluate the usefulness of lymph node biopsies obtained by fine needle aspiration (FNA) for immunophenotyping of non Hodgkin lymphoma (NHL). Seventeen superficial and deep lymph node samples were fractioned for conventional cytological examination and immunophenotyping studies. Out of ten NHL, nine were readily detected by flow cytometry (FC), while failure on the remaining case was due to selective loss of large cell population, which is liable to occur with this procedure. A single case, which proved negative for all markers employed, was finally diagnosed by immunohistochemistry as germ cell tumor. The other six cases, presenting lymphoid population without phenotypic abnormalities, were diagnosed by cytology and/or histology as Hodgkin disease or hyperplasic disorders. To conclude, FC immunophenotyping seems to improve the efficacy of FNA in NHL diagnosis, whereas for Hodgkin disease and hyperplasic disorders, classic morphological criteria are more useful for differential diagnosis. Although FNA for FC immunophenotyping cannot replace histopathological examination for NHL diagnosis, it proves to be a useful tool for staging and follow up, making surgical procedures for sample collection unnecessary.

Trasplante hematopoyético alogénico con células progenitoras extraidas de la sangre periférica. / [Allogeneic hematopoietic transplantation with stem cells extracted from peripheral blood]

Fifty three patients (pts) received an allogeneic hematopoietic transplant using peripheral blood progenitor cells (PBPC). Diagnosis were acute myeloid leukemia (AML) in 16 pts, acute lymphoblastic leukemia (ALL) in 15, chronic myeloid leukemia (CML) in first chronic phase in 12, aplastic anemia in 4, myelodysplasia in 3 and Hodgkins disease, major thalasemia and Hunters syndrome in one each. Mean age was 20 years-old (2-55), 28 males and 25 females. Conditioning regimens were total body irradiation with 1200 cGy and cyclophosphamide 120 mg/kg in 38 pts, busulfan 16 mg/kg and cyclophosphamide 120 mg/kg in 10 pts, total lymphoid irradiation and cyclophosphamide in 3, 2 pts received other chemotherapy based conditionings. PBPC were infused unmanipulated through a central catheter. Graft versus host disease (GVHD) prophylaxis was cyclosporin and short course methotrexate. Donors were 6/6 HLA compatible siblings in 52 cases and 5/6 match in one case. PBPC mobilization was done with G-CSF at a dose of 10 micrograms/kg/day subcutaneously for four days, pheresis started on day 5. Bone marrow harvest was also done in the first thirty cases. Mean cellularities for CD34, CD3, CD4, CD8, CD56, CD19 (cel x 10(6)/kg) were 4.12; 4.59; 2.57; 1.9; 0.55 and 0.68, respectively. Mean recovery of neutrophils > 500/microL was obtained on day +11 and platelets > 20,000/microL on day +13. Patients were hospitalized for a mean period of 26 days (range 18-39) and days with parenteral antibiotics were 12.2 (5-45). Two pts had venoocclusive disease of the liver. Transplant related mortality was 15

. Acute graft versus host disease (GVHD) was observed in 43.4

of pts, only 5 pts had acute GVHD III or IV. Mean time for aGVHD diagnosis was +23 (8-76). Forty three pts were evaluable for chronic GVHD with a mean follow-up of 18 months (4-39). Chronic GVHD was observed in 26.4

by day +240, only 2 pts developed severe cGVHD. The present experience demonstrates an acceptable incidence for cGVHD; however, taking into account recent reports showing an increase of this complication, it seems reasonable not to perform this procedure for non-malignant diseases in which graft versus malignancy effect is not to be expected.

Sindromes mielodisplasticos: experiencia del grupo de estudio y tratamiento de las insuficiencias medulares (Getim) / Myelodysplastic syndromes: experience of the study groups and treatment of medullary failure (Getim)

Se estudiaron 58 pacientes con síndromes mielodisplásticos (SMD), clasificados según los criterios de la FAB. La edad promedio del grupo fue de 61 años (entre 18 y 81). Se evaluaron las alteraciones morfológicas en sangre y médula ósea y los depósitos de hierro extra e intracelulares. Se realizó también determinación de peroxidasa, fosfatasa alcalina lucocitaria, estudio histopatológico de médula ósea, estudio citogenético y cultivo de precursores granulocito-macrofágicos (CFU-GM) en cierto número de pacientes. Hubo seguimiento clínico en 49 pacientes, siendo la sobrevida media observada en los pacientes con anemia rafractaria (AR) de 36,7 meses y los portadores de anemia refractaria con exceso de blastos (AREB) de 15,5 meses. No se obtuvo dato de sobrevida en los otros grupos: anemia sideroblástica (AS), AREB em transformación (AREB-T) y leucemia mielomonocítica crónica (LMMC) por contar pocos pacientes en cada uno. En el momento del diagnóstico, 28 pacientes estaban asintomáticos. Durante la evolución las principales manifestaciones fueron anemia con necesidad tansfusional, infecciones bacterianas y hemorragias cutáneo-mucosas predominantemente. Ocho pacientes fallecieron por leucemia aguda, seis por complicaciones de la citopenia, uno por insuficiencia hepática y cuatro por causas intercurrentes. Fue inconstante el beneficio obtenido con los distintos tratamientos aplicados en forma no randomizada. Consistieron en administración de oximetolona, prednisolona, vitaminas B1, B6. B12, C y folatos; citosina arabinósido a dosis bajas; y ácido 13 cis retinoico. Diez pacientes sufrieron la tansformación a leucemia aguda. No se observó ninguna remisión completa en los seis paciente que recibieron algún tipo de tratamiento antileucémico (AU)