Hematopoietic progenitor cells from patients with myelodysplastic syndromes: in vitro colony growth and long-term proliferation.

It is known that the levels of hematopoietic progenitor cells (HPC) are greatly reduced in the majority of patients with myelodysplastic syndromes (MDS). To date, however, only limited information exists on the growth kinetics of these cells in long-term marrow cultures (LTMC), particularly in terms of erythroid and multipotent progenitors. In the present study, we have determined the HPC content in the bone marrow of 12 MDS patients and followed the proliferation kinetics of myeloid (including granulocyte, macrophage and granulocyte macrophage), erythroid (including early and late) and multipotent progenitor cells in LTMC throughout a 7-week culture period. Both the non-adherent and adherent fractions of the cultures were analyzed, so we were able to look at progenitor cells in suspension and those that physically associated to the stromal cell layer developed in culture. All 12 patients were grouped based on their FAB subtype and the in vitro growth of the HPC was analyzed accordingly. The results presented here indicate that in the majority of MDS patients, pronounced deficiencies exist both in the content and the long-term proliferation of marrow HPC. Such deficiencies were particularly evident for multipotent progenitors and those committed to the erythroid lineage, in which alterations in the maturation process also seem to be present. Our results suggest that, at least in some patients, HPC--besides showing an impaired proliferative capacity--lose their ability to adhere to the stromal cell layers developed in culture. RA patients showed the less affected in vitro HPC growth, whereas HPC from RAEB and RAEB-t showed a markedly deficient growth in culture. Interestingly, myelopoiesis was significantly increased in cultures of CMML patients. These results give some new insights into the biology of MDS-derived HPC.

Deficient proliferation of myeloid, erythroid, and multipotent progenitor cells in long-term marrow cultures from patients with aplastic anemia treated with immunosuppressive therapy.

By using Dexter-type long-term marrow cultures (D-LTMC), it has been shown previously that hematopoietic progenitor cells (HPC) from patients with aplastic anemia (AA) have a deficient proliferation in vitro. The studies reported to date, however, have focused exclusively on granulomonocytic progenitors and no information exists on erythroid or multipotent progenitor cells. On the other hand, in such studies, the input progenitor cell numbers were significantly below normal levels, thus suggesting that the rapid disappearance of myeloid progenitor cells from AA D-LTMC could also be due, at least in part, to their reduced number at culture onset. In the present study, we have followed the kinetics of myeloid, erythroid, and multipotent progenitors, from 24 AA patients subjected to immunosuppressive therapy (including patients that achieved complete, partial, or no remission at all), throughout a seven-week culture period. For analysis, we grouped all the patients based on their initial content of all three types of progenitors. Thus, we were able to evaluate separately the kinetics of these cells in D-LTMC from patients with normal and subnormal levels of progenitor cells. At the time of marrow sampling, most patients showed decreased levels of HPC; in fact, only 21%, 8%, and 16% of them showed normal levels of myeloid, erythroid, and multipotent progenitors, respectively. When cultured in D-LTMC, HPC from all AA patients analyzed showed a relatively fast disappearance from the cultures. Indeed, myeloid progenitors could be detected for only six weeks, whereas erythroid and multipotent progenitors disappeared from the cultures after two and one weeks of culture, respectively. In contrast, in normal marrow D-LTMC, myeloid, erythroid, and multipotent progenitors were detected for at least seven, five, and three weeks, respectively. Such a deficient proliferation was observed even in cultures of AA patients that contained normal levels of HPC at culture onset. Interestingly, no correlation was found between HPC proliferation in D-LTMC and response to treatment. Thus, the results of this study indicate the presence of a functional in vitro deficiency in the hematopoietic system of patients with AA, including those that achieved partial or complete remission after immunosuppressive treatment. Furthermore, this work suggests that such a proliferation deficiency is more pronounced in erythroid and multipotent progenitors than in their myeloid counterparts.

Cytogenetic findings in 303 Mexican patients with de novo acute myeloblastic leukemia.

In this report we show the chromosomal changes seen in a group of 303 Mexican patients with de novo Acute Myeloblastic Leukemia (AML). Two hundred forty-two patients were diagnosed and treated at two hospitals affiliated with the Instituto Mexicano del Seguro Social (IMSS). These are the Centro Medico Nacional Siglo XXI and Centro Medico La Raza Hospitals; the remaining 61 patients were diagnosed and treated at the Hospital General de Mexico (HGM). Clonal abnormalities were detected in 75.6% of the patients; this result agrees with what has been reported in other large series of AML studies. The incidence of changes per hospital was similar in patients from the IMSS hospitals (72-75%), while an increase was seen in patients from the HGM (85.2%). The chromosomal changes seen in this study in order of frequency were: t(15;17)[18.8%], t(9;22)[9.2%], miscellaneous chromosomal changes (mainly rearrangements of chromosomes 1,2,3,12y17)[8.2%], abnormalities of 16q22 [7.3%], t(8;21)[6.3%], -7/del(7q)[5.6%], t(6;9)[5.3%], and abnormalities of 11q23 [4.6%]. We reported an increase in the incidence of certain types of chromosomal changes seen in cases of AML, in comparison with reports from other countries. These differences could be due to methodological variations, although ethnic, socioeconomic and nutritional differences must not be disregarded. We support this finding when comparing distribution of changes in the population of patients seen in the IMSS hospitals with those from the HGM; the main difference lies in the socioeconomic level.

[5 episodes of transient aplastic anemia in 3 patients]. / Cinco episodios de anemia aplástica transitoria en tres enfermos.

We report five episodes of severe aplastic anemia (AA) followed by spontaneous remission in three patients. They were classified as transient aplastic anemia (TAA). Two were females and one male of 32, 56 and 41 years of age, respectively; the man had two recurrences. They had been in contact with insecticides, solvents or drug ingestion. The three had fever, anemia and muco-cutaneous purpura. Supportive measures were used (transfusion of packed red blood cells and platelets, antibiotics, corticosteroids and danazol, the latter two given for ten days in three episodes). They showed spontaneous remission after 16 to 45 days of evolution. The patients did not suffer infection or myeloproliferative disorders which might explain the AA. Transient AA is infrequent and should be considered a variant of AA.

[Interferon in the eradication of the Philadelphia chromosome in chronic myeloid leukemia]. / El interferón en la erradicación del cromosoma Filadelfia de la leucemia mieloide crónica.

OBJECTIVE: To evaluate if human recombinant interferon alpha (IFN) combined with chemotherapy is able to suppress the Philadelphia chromosome clone in patients with chronic myeloid leukemia (CML). MATERIAL AND METHODS: The cytogenetic evolution in 53 patients with CML in chronic phase de novo was studied. They received one of three treatment schemes: a) induction of remission with daunorubicin, vincristine, cytosine arabinose and prednisone (DOAP) and maintenance with IFN (n = 12); b) induction with busulfan (BUS) or hydroxyurea (HYDX) and maintenance with IFN (n = 26); c) induction with DOAP and maintenance with BUS (n = 15). RESULTS: The remission was seen two to six months after the start of treatment: 10 had complete remission, six a partial one, 14 a minor remission and 23 none. The 16 with complete or partial response received treatment with IFN. None of the 15 cases maintained with BUS had complete or partial response. The proportion of cases with complete response (3/12) was slightly lower in patients treated with intensive chemotherapy (BUS/HIDX/IFN) than in those receiving conventional treatment (7/26). CONCLUSIONS: Our results showed that: a) IFN in combination with chemotherapy induced partial or complete response in 30% of our cases; and b) intensive chemotherapy combined with IFN was not superior in terms of a cytogenetic response to treatment with monodrugs (BUS/HIDX) and IFN.

[Treatment of paroxysmal nocturnal hemoglobinuria with antilymphocyte globulin]. / Tratamiento de la hemoglobinuria paroxística nocturna con globulina antilinfocitaria.

OBJECTIVE: To evaluate the effectiveness of antilymphocyte globulin therapy (ALG) in patients with paroxysmal nocturnal hemoglobinuria (PNH). DESIGN: Prospective, non-controlled trial. SETTING: Hematology Service, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, Mexico City. PATIENTS: Six patients were included. The median age was 37.5 years and the male/female ratio was 1:1. All the patients had clinical disease consistent with PNH (hemolytic anemia with some degree of transient or persistent pancytopenia) and also erythrocytes with enhanced sensitivity to complement mediated lysis in vitro, as documented by either the Ham test or the sucrose lysis assay. The criterion for severity was the existence of continuous hemolysis in all and transfusion requirements of two or more packed red cells per month in four cases. Prior to ALG therapy, androgens and/or steroids had been given to five patients with no improvement. INTERVENTION: A single batch of ALG was used during the trial (E 0034, Lymphoglobulin Mérieux, Lyon, France). Patients received an infusion of 10 mg/kg per day in a 20 hours lapse during four consecutive days. Also 500 mg/day of methylprednisolone were started simultaneously with the ALG; it was given for seven days and was gradually tapered off and stopped on day 30. MEASUREMENTS: The increases in hemoglobin, granulocytes and/or platelets as well as decreases in red cell transfusion requirements were used to evaluate the results of therapy. RESULTS: Two patients suffered anaphylaxis after the first administration of ALG and were withdrawn from the study. Two of the four remaining patients responded, one response was total and the other minimal. The responses were transient, and no response was seen in the follow-up of 11-14 months. CONCLUSION: ALG therapy for PNH in the doses and time periods used by us had no beneficial effect in patients with a severe form of PNH.

[Results of the treatment of chronic idiopathic thrombocytopenic purpura with ascorbic acid]. / Resultado del tratamiento de la púrpura trombocitopénica idiopática crónica con ácido ascórbico.

The main objective of the present work is to describe the results of the treatment with ascorbic acid in thirteen patients with refractory chronic idiopathic thrombocytopenic purpura (CITP) and to compare its results with those informed in the literature. The patients received ascorbic acid 2 g/day, orally, in the morning during at least eight weeks. At the end of the period of control there were only four partial responses (30%); the remaining patients did not experience any kind of favorable reaction. Previous publications informed mean partial and complete responses of 11 and 19% respectively. According to such results and those of the present work, and taking into account the generally transitory duration of the response it is concluded that ascorbic acid is of no use in the treatment of CITP.

[The therapeutic advances in adult acute nonlymphoblastic leukemia. The experience at the Hospital de Especialidades of the Centro Médico Nacional Siglo XXI]. / Avances terapéuticos en la leucemia aguda no linfoblástica del adulto. Experiencia en el Hospital de Especialidades del Centro Médico Nacional Siglo XXI.

Acute adult nonlymphoblastic leukemia (ANLL) involves a large group of diseases which originate in an abnormal process of differentiation of the hematopoietic stem cell. This paper analyses the historical background of such a group of malignant hemopathies, current criteria to perform the diagnosis and also the most important therapies used in both the stage of remission induction and the period following this stage (post-remission status). In this context, the therapeutic achievements that have had place during the last two decades at the Hospital de Especialidades del Centro Medico Nacional Siglo XXI are analyzed.

[Advances in the treatment of aplastic anemia]. / Avances en el tratamiento de la anemia aplástica.

The purpose of this paper is to describe the current advances in the pathogenesis, classification and treatment of acquired aplastic anemia (AA). The therapeutical experience obtained at the Servicio de Hematología, Centro Medico Nacional, Siglo XXI is described. Bone marrow transplantation is the first choice therapy for severe AA. This procedure succeeds in obtaining complete remission in nearly 80% of the cases. Nevertheless, few patients are eligible for such therapy, consequently other treatments should be considered. In this context some immunosuppressive therapies such as antilymphocyte globulin had shown to produce favorable responses in 60% of the patients. In addition, androgens and immunosuppressive drugs like methylprednisolone bolus and cyclosporin A do not have a definitive place in severe AA. Finally, it is important to describe the experience with lymphocytapheresis, a new procedure, that decreases the immunological response against the normal hematopoiesis by removing the population of T-lymphocytes inducing complete remission in a few patients.

[Agreement among observers in the classification of acute leukemias]. / Concordancia de observadores en la clasificación de las leucemias agudas.

This study was carried out to establish the level of concordance between two observers from two different health institutions in Mexico City, in the diagnosis of acute leukemias and their different varieties. We studied 73 consecutive cases of adults with these diseases. Each one of the two observers established their diagnosis on two occasions at least 15 days apart. They first made their diagnosis taking as a base the neoplastic cells morphology in bone marrow smears, and after that, with morphology plus specific cytochemistry. The outcomes of the two observers were also compared with the official diagnosis. Kappa test was performed to know interobserver and intraobserver concordance. The kappa values for the diagnosis myeloid/lymphoid were found among the highest (51 to 91). Weighted kappa was also applied to know the level of concordance in the diagnosis of the different varieties of acute leukemia, myeloid and lymphoid. In these cases the weighted kappa values were lower compared with the previous values (lymphoid, from 47 to 82; myeloid, from 30 to 66). Cytochemistry paradoxically was a confusing factor when it was used: in these cases the kappa values were lower (32 to 84) than morphology alone (39 to 91). The outcomes showed the subjective level in the diagnosis of the myeloid subtypes was more important in them than in the lymphoid subtypes.

[Reticulocytopenia and neutropenia in 3 patients with idiopathic autoimmune hemolytic anemia]. / Reticulocitopenia y neutropenia en tres pacientes con anemia hemolítica autoimune idiopática.

Retyculocytopenia and neutropenia or both abnormalities are very infrequent findings during the evolution of patients with acquired autoimmune hemolytic anemia (AIHA). In this paper we describe the clinical cases of three patients with AIHA in whom six different periods of reticulocytopenia were identified; the first two patients also had neutropenia. At the moment of the diagnosis of the cytopenias, the patients did not have a systemic disease, a viral infection or received immunosuppression able to produce them. In every patient the bone marrow cellularity was increased mostly at the expense of normal and macroerythroblasts, containing significant amounts of the other hematopoietic cells. After the diagnosis of AIHA, the patients received supplementary treatment with folic acid which did not produce a remission. The remissions were related to steroids: the neutrophil counts increased importantly one to ten days after starting the steroid administration, whereas reticulocytes reappeared more slowly from 7 to 30 days post-initiation. In patients with AIHA the occurrence of reticulocytopenia and neutropenia have been related to several causes. The favorable responses to steroids in our cases suggests a relationship of steroid with the immunological changes in AHA. It should be pointed out that it is necessary to prolong the followup as done in our three cases. Although these cytopenias may be independent from the hemolytic anemia, we feel our cases suggest that they could be manifestations of a pathologic state not yet characterized.

[Results of severe aplastic anemia treated with antilymphocytic globulin]. / Resultados del tratamiento de la anemia aplástica grave con globulina antilinfocitaria.

The best results of the therapeutic immunosuppression in a plastic anemia have been obtained with antilymphocyte globulin (ALG). Considering this, 14 patients with this disease, 9 females and 5 males, from 8 to 60 years of age, were given ALG (40 mg/K/day/4 days) and corticosteroids. Fifty one percent of them, older than 30 years of age, showed partial or minimal remissions of the disorder. According to this result ALG administration together with bone-marrow transplantation in younger patients may offer effective treatment for a generally fatal disease to a greater number of patients.