Aspectos generales de algunas entidades dentro de los síndromes linfoproliferativos crónicos: La leucemia linfoide crónica / General aspects of some entities within chronic lymphoproliferative syndromes: chronic lymphocytic leukemia

La leucemia linfoide crónica es el tipo de leucemia más común en los países occidentales, afecta con mayor frecuencia al sexo masculino, con una edad promedio al diagnóstico de 65 años. La variedad más frecuente es la de estirpe B; comprenden un grupo de neoplasias biológicamente diferentes, caracterizadas por una proliferación y acúmulo de linfocitos pequeños de apariencia madura en sangre periférica, médula ósea y tejidos linfoides. Es el prototipo de enfermedad maligna que involucra a defectos de la muerte celular programada o apoptosis. Esta enfermedad puede presentar variaciones en sus características inmunofenotípicas, clínicas, citogenéticas y moleculares. Aproximadamente, el 80 por ciento de los pacientes con leucemia linfoide crónica B presentan anormalidades cromosómicas, principalmente: deleciones de los cromosomas 11,13, 6,14 y 17, estas tres últimas de mal pronóstico. Pueden presentar además, disfunciones inmunes responsables de inmunodeficiencia y autoinmunidad. Se desconoce la causa de esta enfermedad aunque los informes iniciales sugieren la implicación de los genes Bcl-1 y Bcl-2, es por eso que la terapia actual está dirigida a la inhibición de Bcl-2 por ser el responsable en la regulación de la apoptosis(AU)

Chronic lymphoid leukemia is the most common type of leukemia in Western countries, which most often affects males and the average age at diagnosis is 65 years. The most common form is the B-cell and is described in this article. LLC comprise a biologically distinct group of neoplasms characterized by proliferation and accumulation of small mature lymphocytes appearance in peripheral blood, bone marrow and tissues linfoides. Is the prototype of malignant disease involving defects programmed cell death or apoptosis. This disease may present variations in their immunophenotypic, clinical, cytogenetic and molecular characteristics. Approximately 80 percent of patients with B-CLL have chromosomal abnormalities, mainly: deletions of chromosomes 11, 13, 6, 14 and 17. These last three are bad prognosis. The patients with CLL may have also immune dysfunctions responsible for immunodeficiency and autoimmunity. It is unknown the cause of CLL although initial reports suggest the involvement of Bcl-1 and Bcl-2 gene is why the current therapy is directed to inhibition of Bcl-2 as this is responsible in regulating apoptosis(AU)

Comparative Analysis of the Distribution of Various Subtypes of Lymphoid Malignancies in Uttarakhand with other Regions in India.

Lymphoid malignancies (LM) form an umbrella term comprising both Hodgkin Disease (HD) and Non Hodgkin Lymphoma (NHL). A number of studies conducted in India and worldwide suggests that the disease exhibits similar pattern with contrasting regional variations. Examining regional variations is important as it may provide an insight to the etiological factor and pathogenesis of the disease. Aim: The aim of our study was to investigate the current pattern of lymphoid malignancies both HD and NHL in Uttarakhand and subsequently compare the results with other regions. Materials and Methods: We analyzed 116 cases of Lymphoid Malignancies that were reviewed over a period of 18 months. Both HD and NHL were diagnosed morphologically and then Immunohistochemistry (IHC) using CD3, CD15, CD20, CD30, and CD45 was employed to further subtype disease according to current WHO classification. Results: The lymphoid malignancies were further subdivided into HD and NHL. Nodular Sclerosis (NS) was the dominant subtype of HD in Uttarakhand (48.78%) and was comparable with results from other regions. Statistical analysis regarding distribution of various subtypes of HD in Uttarakhand and its comparison with three distinct geographical regions also showed p value < 0.241832 which was not statistically significant. However, amongst NHL Diffuse Large B cell Lymphoma (DLBCL) (54.66%) was the commonest subtype. Besides, a significant number of cases of Anaplastic Large Cell Lymphoma (12%) were also observed. Furthermore, statistical analysis showed that the distribution of various subtypes of NHL in Uttarakhand when compared to three distinct geographical regions was statistically significant (P value < 0.002808). Conclusion: Geographic differences in the incidence and histologic subtypes of Lymphomas do exist.

Aspectos clinicoepidemiológicos de la leucemia linfoide crónica / Clinical epidemiological aspects of chronic lymphoid leukaemia

Se hizo un estudio descriptivo y retrospectivo de 71 pacientes con leucemia linfoide crónica, atendidos en el Servicio de Hematología del Hospital General Docente Dr Juan Bruno Zayas Alfonso de Santiago de Cuba, desde enero del 2001 hasta noviembre del 2006, con vistas a identificar algunas variables clinicoepidemiológicas en ellos, mostrar las terapéuticas más empleadas, así como evaluar la supervivencia, las principales causas de la entidad clínica y la mortalidad. En la serie predominaron los ancianos, el sexo masculino y la categoría de alto riesgo correspondiente a los estadios avanzados. El esquema terapéutico de clorambucil y prednisona fue el más empleado, con buenos resultados en la mayoría de los integrantes de la casuística. La supervivencia de los pacientes, en general, osciló entre 1-5 años, en tanto las muertes ocurridas fueron causadas por progresión de la enfermedad, procesos infecciosos respiratorios, transformación prolinfocítica, segundas neoplasias y accidentes vasculares encefálicos.

A descriptive and retrospective study of 71 patients with chronic lymphoid leukemia, attended at the Hematology Service from Dr Juan Bruno Zayas Alfonso Teaching General Hospital in Santiago de Cuba was carried out from January, 2001 to November, 2006, in order to identify some clinical epidemiological variables on them, to show the therapeutical variables more used, as well as to assess survival, mortality, and the main causes of the clinical entity. Elderly, male sex, and high risk category related to advanced stage were predominant in the series. The therapeutical schedule of chlorambucil and prednisone was the most used, achieving good results in the majority of the case material. The survival of patients, in general, ranged among 1-5 years, whereas deaths occurred due to disease progression, infectious respiratory processes, pro-lymphocytic transformation, second neoplasias, and strokes.

Avaliação epidemiológica das leucemias linfoblásticas em crianças brasileiras e implicação de infecções na sua patogênese

A LLA é a neoplasia mais comum na infância, ocorrendo principalmente entre 2-5 anos. As hipóteses atuais sugerem a necessidade de dois eventos moleculares agindo na patogênese da LLA de células B precursoras. O primeiro evento seria uma lesão genética que ocorreria durante a vida intra-uterina e o segundo evento seria conseqüente à ação de uma infecção viral neste clone aquiescente. Pouco tem sido descrito sobre a epidemiologia das leucemias agudas no Brasil. Atualmente, com o estabelecimento de registros de câncer pediátrico, é possível analisar estes dados. Para avaliar estas hipóteses na população brasileira, que difere da população estudada nos países desenvolvidos pela exposição à patógenos, assim como no acesso a saneamento básico, realizamos um estudo epidemiológico, numa coorte de pacientes com LLA cujas amostras biológicas foram enviadas ao laboratório no contexto de rede de referência nacional. Estimamos a incidência de LLA em três cidades diferentes, utilizando o método de captura-recaptura e analisamos a exatidão do registro de câncer de base populacional destas três cidades. A incidência estimada de LLA foi 5,76/100 000 em Salvador, 6,32/100 000 em Recife e 3,20/100 000 em Belo Horizonte. A taxa de subnotificação foi de 84,5%, 64,6% e 50% para cada cidade, respectivamente. Também realizamos sorologia para Parvovírus B19 e Herpesvírus-6, assim como a dosagem de proteína C reativa (um marcador de inflamação), não tendo havido diferença entre os 110 pacientes com LLA e os 67 controles para nenhum destes testes. A prevalência de anticorpos (IgG) anti-HHV-6 e anti-PVB19 em pacientes com LLA de células B precursoras foi de 76% e 42,4% , respectivamente.Finalmente, descrevemos a prevalência de anticorpos anti-leishmania em 243 crianças com LLA, 73 com LMA e 55 crianças sem neoplasia, que foi, respectivamente, 3,7%, 5,5% e 14,5%. A concordância entre os testes RIFI e ELISA foi de 83%. 13 pacientes apresentavam leishmaniose visceral no momento do diagnóstico da leucemia aguda. Nosso estudo demonstra que a incidência de LLA em crianças no Brasil pode ser maior do que o registrado até o momento devido à deficiência dos registros de câncer de base populacional, o que tem implicações no estudo da patogênese da LLA, visto que as hipóteses levam em consideração a menor incidência da doença em países em desenvolvimento. Encontramos que a prevalência de anticorpos contra Parvovírus B19 e Herpesvírus-6 é similar à da população em geral, não havendo uma associação entre estas doenças e a LLA nesta amostra. Demonstramos que existe uma associação entre leishmaniose visceral e LLA, pois esta parasitose pode dificultar o diagnóstico da leucemia, estar associada à mesma no diagnóstico, mas não foi possível demonstrar um papel desta doença na patogênese da leucemia.

Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood, occurring mainly between ages 2-5. There are different hypothesis on ALL pathogenesis that states that two different hits are necessary to ALL development. The first one would be a molecular lesion occurring during intra-uterine life. The second one would be a common childhood viral infection. Few have been described about acute leukemia’s epidemiology in Brazil.To evaluate Brazilian population on regard ALL’s pathogenesis, we studies children whose blood was sent for diagnosis proposal. We estimated ALL’s incidence in three different cities and the completeness of population-based cancer registry (BPCR) using capture-recapture method. The estimated incidence was 5, 76/100 000 in Salvador, 6, 32/100 000 in Recife and 3, 20/100 000 in Belo Horizonte. The completeness of the BPCR was 15.5%, 35.4% and 50% for Salvador, Recife and Belo Horizonte, respectively. We also evaluated the seroprevalence of antibodies against Parvovírus B19 and Herpesvírus-6, as well as measurements of C-reactive protein. The seroprevalence of IgG antibodies against, HHV-6 and PVB19 in B-cell precursor ALL’s patients was 76% and 42, 4%. Finally, we described the seroprevalence of antibodies against visceral leishmaniasis in 243 ALL’s children, 73 with AML and 55 controls: 3,7%, 5,5% and 14,5%, respectively. Concordance between IFI and ELISA was 83% and 13 patients presented acute visceral leishmaniasis at the time of acute leukemia diagnosis.We found out that ALL’s incidence could be higher than described in Brazil because of PBCR underreporting. The prevalence of antibodies against Parvovirus B19 and Herpesvirus-6 was similar to that in general population, not confirming a role for those infections in ALL’s pathogenesis. Visceral leishmaniasis seems to be associated with ALL as it can mimic this disease and also be concomitant to it.

Incidencia de las Leucemias y los Mielomas en Cuba (1986-1990) / Incidence of leukemias and myelomas in Cuba (1986-1990)

En Cuba, las leucemias y mielomas (L y M) se incluyen tradicionalmente en las listas de las 10 localizaciones más frecuentes tanto en la incidencia como en la mortalidad por cáncer. Se describe la incidencia de las L y M en Cuba entre los años 1986 y 1990 de acuerdo con las principales variables epidemiológicas: edad, sexo y variedad histológica. Se incluyeron todos los casos reportados al registro nacional de cáncer (RCN) por L y M entre 1986 y 1990. Fueron calculadas las tasas específicas para los grupos de edad y las tasas estandarizadas a la población mundial según el sexo y la variedad histológica. Fueron notificados al RCN 4 179 casos con L y M, unos 836 casos por año con una tasa cruda de 7,98. Las leucemias fueron la mayoría de estas neoplasias, siendo las más frecuentes las mieloides. Las leucemias linfoides agudas tuvieron el más alto índice de masculinidad y mostraron la típica curva bimodal de esta enfermedad. Para las leucemias linfoides crónicas, en el grupo de hombres enfermos de 85 años y más las tasas fueron más del doble del mismo grupo en el sexo femenino. Las leucemias mieloides mostraron un abrupto incremento de las tasas específicas después de los 45 años. Los mielomas representaron el 28,31 por ciento de todas las neoplasias estudiadas, la distribución por edades de sus tasas muestra un riesgo muy pequeño en la niñez y la juventud y un incremento considerable de las tasas a partir de los 45 años. Se sugiere un necesario salto positivo en la cobertura del RNC a los servicios hematológicos del país y en la calidad del diagnóstico diferencial de las L y M, actualmente más del 50 por ciento de los casos son reportados sólo a través de los certificados de defunción

Incidence trends of acute leukemia among the children of Mexico City: 1982 - 1991

The objective of this study was to identify the tendency of acute leukemia among children in Mexico City from 1982 to 1991. A hospital survey was performed. Medical records of children under 15 years of age with a diagnosis of acute leukemia were reviewed. The cases were chosen from hospitals which provide medical attention to children with cancer in Mexico City. The annual incidence rate (AIR) was calculated in general, by sex, age groups (under 1 year of age, from 1 to 4 years, 5 to 9 years and 10 to 14 years) and standardized with the world population. The trend was evaluated with Sperman's correlation method. Acute lymphoblastic leukemia showed a significantly increasing trend during the study period. The AIR was 7.75 (per million) in 1982 and 22.19 (per million) in 1991. For age groups a tendency to increase was observed in female of age group 1 to 4 years and in males of age group 10 to 14 years. Acute non-lymphoblastic leukemia did not display a specific trend. In conclusion, acute lymphoblastic leukemia shows a tendency to increase in the children of Mexico City