RESUMEN
AIM: To analyze the efficiency and reproducibility of the ALL-2009 protocol within the Russian prospective multicenter study based on different principles of cytostatic effects (non-intensive, but continuous cytotoxic treatment and a small number of allogeneic hematopoietic stem cells). SUBJECTS AND METHODS: The ALL-2009 (NCT01193933) study conducted in April 2009 to December 2016 included 194 patients (95 males and 99 females) aged 15 to 55 years (median age 28 years) with Ph-negative B-cell acute lymphoblastic leukemia (ALL). There was early pre-B-cell ALL in 54 patients, common ALL in 101, pre-B ALL in 39, initial leukocytosis in 9.4·109/l (0.4-899.0), lactate dehydrogenase in 901 IU (31-13 059), an initial central nervous system lesion in 17 (8.7%), mediastinal injury in 3 (1.5%), and splenomegaly in 111 (57.2%). The results of standard cytogenetic analysis are known in 113 (60.4%) patients. Normal karyotypes were detected in 49 (54.5%) out of the patients; t(4;11) in 9 (5.4%), t(1;19) in 2 (1.2%), and other karyotypic abnormalities in 53 (46.9%). Thirteen (7.8%) patients underwent allogeneic hematopoietic stem cell transplantation in first complete remission (CR); their proportion did not differ in the federal and regional centers. RESULTS: The frequency of CR achievement was the same in the federal and regional centers and generally amounted to 87.5%. Early (8.8%) and CR (9.6%) mortality rates remained high despite the low aggressiveness of cytotoxic action, necessitating the improvement of auxiliary treatment. The five-year overall survival (OS) rates vary considerably in the federal and regional centers (72.6 and 43.8%), the relapse-free survival (RFS) (70.2 and 53.4%) and recurrence risk (23.1 and 36.5%) are comparable. This suggests that the non-intensive, but continuous exposure principle built in the ALL-2009 protocol makes it possible to reproduce the envisaged treatment program and to achieve satisfactory results. CONCLUSION: The ALL-2009 protocol allows both the federal and regional centers to obtain the long-term results comparable with those of current foreign studies: OS (54.2%), RFS (56.5%); and relapse risk (35.4%). Multivariate analysis has identified age (over 30 years), initial leukocytosis (30·109/l and more) and t(4;11) among the main clinical prognostic factors. Gene mutation detection evaluated in a small number of patients (8/36) is not a poor prognostic sign. There is a need for further investigations with centralized evaluation of the mutation status of leukemic cells and the clearance of minimal residual disease.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Prolinfocítica Tipo Células B , Inducción de Remisión/métodos , Enfermedad Aguda , Adulto , Femenino , Humanos , Quimioterapia de Inducción/métodos , Quimioterapia de Inducción/estadística & datos numéricos , Leucemia Prolinfocítica Tipo Células B/diagnóstico , Leucemia Prolinfocítica Tipo Células B/epidemiología , Leucemia Prolinfocítica Tipo Células B/terapia , Masculino , Pronóstico , Estudios Prospectivos , Reproducibilidad de los Resultados , Federación de Rusia/epidemiología , Prevención Secundaria/métodos , Prevención Secundaria/estadística & datos numéricos , Análisis de SupervivenciaRESUMEN
AIM: to analyze well-known risk factors (RFs), such as age, immunophenotype, baseline leukocytosis, enhanced lactate dehydrogenase (LDH) activity, time to achieve complete remission, a risk group, and cytogenetic abnormalities) in patients with acute lymphoblastic leukemia (ALL) in the use of the ALL-2009 protocol. SUBJECTS AND METHODS: The protocol covered 298 patients (137 women (including 13 pregnant women) and 161 men) aged 15 to 55 years (median age 28 years) with Ph-negative ALL. The phenotype was unknown in 6 patients. Three (1%) were ascertained to have a biphenotypic variant. 182 (62.4%) patients were found to have B-cell ALL (early pre-B ALL (n=51); common ALL (n=92), and pre-B ALL (n=39); 107 (36.6%) patients had T-cell ALL (early T-ALL (n=56); thymic T-ALL (n=41), and mature T-ALL (n=10). According to the baseline clinical and laboratory parameters (leukocytosis of 30·109/l and more for B-ALL; and that of 100·109/l and more for T-ALL; phenotype Ð-I for B-ALL, phenotype Т-I-II-IV for T-ALL; LDH activity was more than twice the normal values; the presence of translocation t(4;11)), the high-risk group included most patients with B-ALL (n=110 (72.8%)) and T-ALL (n=76 (76%)). Thirty-five patients with T-ALL underwent autologous bone marrow transplantation (BMT). Allogeneic BMT was performed in 18 (7%) of the 258 patients who had undergone an induction phase. RESULTS: Five-year overall survival for all the patients included in the investigation was 59%; relapse-free survival was 65%, which was significantly different in the patients with B-ALL and in those with T-ALL: the overall survival rates were 53.3 and 67.5% (p=0.1); the relapse-free survival was 56 and 79% (p=0.005), respectively. Multivariate analysis including the well-known RFs demonstrated that the latter for T-ALL were of no independent prognostic value and only the patient's age was identified for B-ALL (p=0.013). CONCLUSION: A lower chemotherapeutic load and a small number of allogeneic BMTs did not affect total positive treatment results in adult patients with ALL, by complying with the principle achieving the continuity of cytostatic effects and by preserving the total cytostatic loading dose. The results of the Russian investigation casts some doubt on the necessity of using very intensive consolidation cycles and performing a large number of allogeneic BMTs in adult patients with ALL.
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Protocolos Clínicos , Evaluación de Resultado en la Atención de Salud , Leucemia-Linfoma Linfoblástico de Células Precursoras , Complicaciones del Embarazo , Adolescente , Adulto , Trasplante de Médula Ósea , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células Precursoras/clasificación , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Embarazo , Complicaciones del Embarazo/epidemiología , Complicaciones del Embarazo/metabolismo , Complicaciones del Embarazo/terapia , Factores de Riesgo , Trasplante Autólogo , Adulto JovenRESUMEN
AIM: To analyze the efficiency of the ALL-2009 protocol (ClinicalTrials.gov NCT01 193933) in patients with T-cell leukemias, particularly the role of autologous hematopoietic stem cell transplantation (auto-HSCT) after non-myeloablative BEAM conditioning, followed by maintenance therapy. SUBJECTS AND METHODS: Since 2009, the ALL-2009 study has enrolled 90 patients with T-cell acute lymphoblastic leukemia (T-ALL), the treatment results were assessed in 86 patients: 6 and 28 patients underwent allogeneic HSCT and auto-HSCT, respectively. A landmark analysis was used to compare survival rates in patients who had undergone auto-HSCT and in those who had not. For this, the median time from complete remission to the date of auto-HSCT was determined (the median was 6 months). Then to compare with the auto-HSCT group, only 27 patients who had been in complete remission for 6 months or more were included in a chemotherapy group. RESULTS: The achievement of complete remission in patients with thymic T-ALL (100%) was significantly higher than in those with early (85.7%) or mature (70%) variants. The patients with early and mature T-ALL as compared to those with thymic T-ALL showed high death rates in the remission induction (7.4 and 10% versus 0) and the patients with mature T-ALL had a.higher proportion of refractory forms (20% versus 0). The 5-year overall and relapse-free survival rates in all the T-ALL patients were 66 and 76%, respectively. After auto-HSCT, the risk of recurrence was 0% versus 21% after chemotherapy (p=0.03). The relapse-free survival rates significantly differed in the auto-HSCT and non-auto-HSCT groups: 100 and 66%, respectively (p=0.047). CONCLUSION: The long-term survival rates obtained during this multicenter study in the T-ALL patients treated according to the ALL-2009 protocol, the basis for which is the principle of continuity of cytostatic effects, are exclusively optimistic. Late consolidation with auto-HSCT following non-myeloablative BEAM conditioning, followed by maintenance therapy, considerably reduces the risk of recurrence.
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Trasplante de Células Madre Hematopoyéticas/métodos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/cirugía , Adulto , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células T Precursoras/mortalidad , Inducción de Remisión , Estudios Retrospectivos , Federación de Rusia/epidemiología , Tasa de Supervivencia/tendencias , Trasplante Autólogo , Trasplante Homólogo , Resultado del Tratamiento , Adulto JovenRESUMEN
AIM: To assess the main epidemiological characteristics of chronic myeloid leukemia (CML) in the Russian Federation. SUBJECTS AND METHODS: A planned epidemiological prospective study was conducted in 2009-2012 in 6 Russian regions with the total number of 10.1 million inhabitants, which notified all new CML cases. RESULTS: The unstandardized (unnormalized, baseline) recorded incidence of CML in the examined regions was 0.58 per 100,000 annually. Its standardized (normalized) incidence was 0.70 for the WHO standard population and 0.72 for the European standard population. The regional variations in the incidence were 0.44 to 0.69. The structural analysis of the incidence in the age strata indicated that the overall morbidity was less due to the decreased rate of registration in old age groups. The morbidity rates in patients aged less than 60 years were nearly similar to the European rates; those in patients aged over 70 years were almost 10 times lower. The lower rate of detection and screening diagnosis of CML in pensioners in primary health care is discussed. CONCLUSION: The data obtained in this study may serve as the starting point for monitoring the CML epidemiological situation.
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Leucemia Mielógena Crónica BCR-ABL Positiva/epidemiología , Adulto , Factores de Edad , Anciano , Humanos , Incidencia , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Leucemia Mielógena Crónica BCR-ABL Positiva/terapia , Persona de Mediana Edad , Sistema de Registros , Federación de Rusia/epidemiologíaRESUMEN
AIM: To give the preliminary results of the AML-01.10 Russian multicenter randomized trial to treat adult acute myeloid leukemia (AML), the basic principle of which is to use high-dose anthracycline antibiotics in induction/consolidation. SUBJECTS AND METHODS: By December 2011, 145 patients with AML had been randomized from 18 hematology centers of 15 cities and towns of the Russian Federation; the median age of all the patients was 44 years. Seventy-one patients were analyzed in August 2011 (a 1.5-year follow-up). RESULTS: The efficiency of 2 courses 7+3 using high-dose daunorubicin (60 mg/m2 per administration) and continuous infusion of cytarabine during the second course was high and comparable with that in the use of a high-dose HAM protocol as a second induction course and can achieve a complete remission in 74.6%. The protocol toxicity evaluated from its early mortality (11.3%) and its death in complete remission (16.6%) was permissible, particularly by taking into consideration the multicenter pattern of the trial. At the completion of analysis, 53 (68.8%) out of the 77 patients on whom the data on their vital status were available were alive. In this follow-up period, the frequency of recurrences was 19.2% (10/52). Only 3 (4.2%) patients out of the 71 patients in whom the efficiency of the protocol had been completely evaluated underwent allogeneic bone marrow transplantation. CONCLUSION: The total high dose (720 mg/m2) of anthracycline antibiotics, which is used in the period of induction and consolidation, determines the long periods of myelosuppression and intercourse intervals. Protocol deviations (no course of consolidation therapy, lower-dose idarubicin during consolidation therapy, a course of low-dose cytarabine, between the courses of induction and consolidation chemotherapy, and very long intercourse intervals) were recorded in a total of 20 (28%) patients.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Trasplante de Médula Ósea/métodos , Leucemia Mieloide Aguda/tratamiento farmacológico , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Terapia Combinada , Citarabina/administración & dosificación , Daunorrubicina/administración & dosificación , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Humanos , Leucemia Mieloide Aguda/patología , Leucemia Mieloide Aguda/terapia , Masculino , Persona de Mediana Edad , Recurrencia , Inducción de Remisión/métodos , Federación de Rusia , Factores de Tiempo , Trasplante Homólogo , Resultado del Tratamiento , Adulto JovenRESUMEN
AIM: To review results of 2-year experience in execution of the protocol on the treatment of adult acute Ph-negative lymphoblastic leukemia ALL-2009. MATERIAL AND METHODS: Of 111 patients registered in the study from November 2008 to December 2010 the analysis covered 96 patients from 23 hematological centers in 18 towns of the RF. RESULTS: Treatment according to the Protocol ALL-2009 resulted in achievement of a complete remission in 91.2% patients with low early lethality of 5.5%. Postremission lethality fell to 3.7% versus previous studies (22%). Overall 2-year survival and recurrence-free survival reached 77.6 and 78.4%, respectively. Detection of any chromosomic aberrations significantly affected recurrence-free survival: 74 vs 100% in patients with normal karyotype. CONCLUSION: Protocol All-2009 demonstrates high efficacy in moderate toxicity and good reproducibility in any hematologic center.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cromosoma Filadelfia , Proyectos Piloto , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Recurrencia , Inducción de Remisión , Adulto JovenRESUMEN
AIM: To comparatively analyze the toxicity of 4 treatment protocols in patients with acute myeloid leukemia (AML), which were used in the Russian multicenter center in 1992 to 2009. MATERIALS AND METHODS: The information obtained in 4 Russian multicenter studies conducted in 33 hematology departments of 26 cities and towns of the Russian Federation in 1992 to 2009 was analyzed. Randomization was made in 243 patients with AML (median age 38 years) in 1992-1995, 396 patients (median age 39 years) in 1995-1999, 392 patients (median age 39 years) in 2001-2006, and 137 patients (median age 40 years) in 2006-2009. The analysis excluded patients with acute promyelocytic leukemias who were recruited in the AML-92 and AML-95 studies. These patients' statutory forms adequately filled in were 60-70% therefore toxicity was analyzed on the basis of the data of 631 patients. RESULTS: The baseline clinical and laboratory parameters in the patients enrolled in the studies in different years slightly differ in the count of leukocytes at the onset of the disease and in the level of lactate dehydrogenase (LDH): the recent studies revealed a larger number of high-risk group patients (leukocytes more than 30 10(9)(/l; LDH more than 500 units) possibly due to the later diagnosis of AML. During the studies, the number of complete remissions remained as before (55%) after the first course and increased from 65 to 78% after the second course using cytosine arabinoside in high doses. Despite treatment intensification, mortality in the induction period remained as before (19-21%). Remission mortality decreased from 18 to 10-13%. The long-term results of using the aggressive therapy did not differ from those obtained during the standard treatment protocols. The duration of leucopenia after standard induction courses during the all studies remained equal (17-19 days); the exclusion was a HAM course as the second induction course after which the duration of neutropenia was much more than that of the standard course (17 and 10 days, respectively). During the study years, there was an increase in platelet transfusion volumes (from 20 to 53 doses during the first course and from 7 to 28 doses during the second course) and a reduction in the percentage of severe hemorrhagic complications. The incidence of pneumonias remained at the same level (40-50%) during the induction courses and that of septic complications and necrotic enteropathy considerably decreased from 40-46 to 17-19%. The incidence of invasive aspergillosis during the current programs from AML treatment was 10% (two induction courses), that of invasive candidiasis was 4.7% (two induction courses). CONCLUSION; The long-term results of treatment for AML were virtually unchanged regardless significant therapy intensification. Mortality remained high during induction treatment and in the postremission period. Its cause is severe infectious complications developing during myelotoxic agranulocytosis. The results of the analysis provide the basis for developing a new AML treatment protocol that should take into account all the merits and demerits of the previous protocols and provide a toxicity-treatment efficiency balance.
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Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Leucemia Mieloide Aguda/sangre , Leucemia Mieloide Aguda/tratamiento farmacológico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Supervivencia sin Enfermedad , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Humanos , L-Lactato Deshidrogenasa/sangre , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Recuento de Leucocitos , Leucocitos/citología , Leucopenia/sangre , Leucopenia/inducido químicamente , Leucopenia/epidemiología , Neutrófilos/citología , Infecciones Oportunistas/sangre , Infecciones Oportunistas/epidemiología , Infecciones Oportunistas/etiología , Transfusión de Plaquetas , Inducción de Remisión , Federación de RusiaRESUMEN
AIM: To analyse the results of the treatment according to ALL-2005 protocol for adult patients with acute lymphoblastic leukemia (ALL); on the basis of the summarized evidence on ALL treatment to propose principles for development of a new program of ALL treatment in 15-55-year-old patients. MATERIAL AND METHODS: Five hematological centers (in Moscow, Saransk, Volgograd, Tambov, Kirov) participated in ALL-2005 protocol trial initiated in 2005. A total of 71 adult patients with ALL (age median 27 years) were treated. The results of the MB-2002 study with participation of 16 patients aged 16-23 years performed in the State Hematological Research Center (SHRC) were reviewed RESULTS: The results of the induction therapy according to ALL-2005 protocol conducted in Moscow SHRC were good: a complete remission was achieved in 90% patients, early lethality was 6%, resistance was observed in 4%. In regional centers lethality in remission was higher, 5-year overall survival was 28% (in SHRC it was 56%), recurrence-free survival in regional center was 22% versus 51%, respectively. Long-term response by ALL-2005 and MB-2002 in patients aged 19-23 was the same, but toxicity of ALL-2005 treatment was higher (no lethality and 5, 4% in induction and remission, respectively). CONCLUSION: The decision was made on design of a new protocol of treatment of Ph-negative ALL for patients aged from 15 to 55 years the main principles of which are the following: continuous treatment with modification of cytostatic drugs doses depending on myelosuppression severity; assessment of tumor cells sensitivity to prednisolone and its replacement for dexametasone throughout the treatment; prolongation of L-asparaginase treatment with elevation of its total dose; monitoring of minimal residual disease (MRD) for decision on late intensification in patients with MRD at late treatment stages (5 months).
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Adolescente , Adulto , Factores de Edad , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Trasplante de Médula Ósea , Supervivencia sin Enfermedad , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células Precursoras/cirugía , Adulto JovenRESUMEN
AIM: Systematization of the results of 20-year multicenter randomized trial of the efficacy of treatment of acute myeloid leukemia (AML) of adults; presentation of the design of the study of the strategy of consolidation and maintenance therapy after high-dose consolidation initiated in 2007. MATERIAL AND METHODS: Treatment outcomes on the protocol AML-01.01 are presented for 354 AML patients from 29 hematological centers located in 22 towns of Russia and 2 towns of Ukraine. The patients were randomized into 3 groups by variant of therapy: 124 patients (62 males and 62 females; age median 42 years) received 4 courses of 7+3+VP-16 and 5 courses of maintenance therapy (7+3 with thioguanin); 130 patients (65 males and 65 females, age median 41 year) received 2 courses of 7+3+VP-16, 2 courses 7+3, maintenance--5 courses 7+3 with thioguanin; 126 patients (57 males and 68 females, age median 40 years) were given 2 courses of 7+3+VP-16, 2 HAD courses, treatment discontinuation. RESULTS: A complete remission after the first course of 7+3+VP-16 was achieved in 55% patients, after the second course--in 30% after the course 7+3+VP-16 or 7+3 with mitoxantron, in 70%--after NAM. Overall and recurrence-free survival were 18 and 35%; 30 and 20%; 36 and 30%, respectively. There was no significant difference in efficacy of the treatment scheme. CONCLUSION: The multivariate analysis has shown that a leading factor having impact on treatment results was the number of randomized patients: the less patients were randomized, the worse were the results.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/mortalidad , Enfermedad Aguda , Adulto , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Mitoxantrona/administración & dosificación , Recurrencia , Tioguanina/administración & dosificación , Resultado del TratamientoRESUMEN
Analyzes statistics of induced abortions as reflected at the Ministry of Health and Medical Industry of Russia. Puts forward the most significant medicosocial factors influencing the causes of pregnancy discontinuation. Analysis of the prevalence of induced abortions in different regions of Russia persuasively demonstrates the necessity of improving the state statistics of abortions for the realization of family planning programs.
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Aborto Inducido/estadística & datos numéricos , Adolescente , Adulto , Femenino , Humanos , Embarazo , Federación de RusiaRESUMEN
Presents the results of a random social hygienic study devoted to family planning, carried out in the town of Tver and its region. The objects of this study were medical and university students and physicians specialized in obstetrics and gynecology engaged in family planning problems. Contraception behavior of young people was analyzed and the structure of contraception in Russia compared with that in countries with well-developed economy. Family planning problems viewed by present-day young people are discussed: the optimal marriage age and time of appearance of the first baby, the desired number of children, intergenetic intervals, and pregnancy outcomes. The attitude of obstetricians and gynecologists to contraception, their knowledge and skills in this sphere are analyzed. Shortcomings in the activities of obstetrical and gynecological service in family planning and contraception are discussed.
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Conducta Anticonceptiva , Servicios de Planificación Familiar , Adolescente , Adulto , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Embarazo , Distribución Aleatoria , Federación de Rusia , Esterilización Reproductiva , Estudiantes , Encuestas y CuestionariosRESUMEN
Blood cells of 13 children with Diamond-Blackfan syndrome and their parents were examined for some immunological characteristics of lymphocytes and the activity of adenosine desaminase (ADA), purine nucleoside phosphorylase (PNP). Acute stage of the disease was characterized by high ADA activity of red blood cells and normal PNP activity in 75% of the patients. In remission these abnormalities persisted. High ADA activity was noted in 6 out of 14 parents of the children. Immunological investigation of the patients' lymphocytes revealed marked shifts in T-cellular immunity which may be responsible for impaired regulation of proliferation and differentiation of erythroid precursors registered in unbalance of purine degradation enzymes activity.
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Anemia de Fanconi/enzimología , Anemia de Fanconi/inmunología , Nucleótidos de Purina/sangre , Subgrupos de Linfocitos T/inmunología , Adenosina Desaminasa/sangre , Adulto , Niño , Preescolar , Eritrocitos/enzimología , Femenino , Humanos , Inmunidad Celular , Lactante , Masculino , Purina-Nucleósido Fosforilasa/sangreRESUMEN
Subpopulations of rosette-forming cells were studied in lymphoid pools of peripheral blood and bone marrow of 24 children with acquired aplastic anemia, after a course of treatment with antilymphocytic globulin (ALG). After termination of the preparation transfusion a decrease in the levels of "active" T-lymphocytes and cells with C3-receptors was recorded. The levels of immature T-lymphocytes were found to be lowered four weeks after ALG-therapy, while other subpopulations remained within the normal. The lowering activity of immunogenesis in the bone marrow combined with hemopoietic recovery after the immunosuppressive therapy have evidenced a possible participation of immunologic mechanisms in the pathogenesis of acquired aplastic anemia in children.