Clinical Characteristics of Monomorphic Post-transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLD) are a heterogeneous group of lymphoproliferative disorders associated with immunosuppression and Epstein-Barr virus infection. PTLD is classified into three major categories: early lesions, polymorphic PTLD, and monomorphic PTLD. The majority of monomorphic PTLD cases are non-Hodgkin's lymphoma of B-cell origin. This retrospective study was conducted to investigate the incidence, clinical manifestation, treatment, and outcomes of monomorphic PTLD among 5,817 recipients of solid organ or allogeneic hematopoietic stem cell transplantation from five institutions. Fourteen patients with monomorphic PTLD were identified (male:female 11:3; median age 42.6 yr, range 24-60). The overall incidence rate was 0.24%. The most common disease type was diffuse large B cell lymphoma (n=7). The median time between the transplant and diagnosis of PTLD was 85.8 months. However, all cases of PTLD after allogeneic hematopoietic stem cell transplantation occurred within 1 yr after transplantation. Ten of the 14 patients had EBV-positive tumor. Fourteen patients received combination systemic chemotherapy and four patients were treated with radiation therapy. Ten patients achieved a complete response (CR) and two patients a partial response (PR). The median follow-up period for surviving patients was 36.6 months. Nine patients remain alive (eight CR, one PR). Nine of 11 solid organ transplantations preserved graft function. The present study indicates a lower incidence rate and a longer median time before the development of PTLD than those of previous reports. Careful monitoring was needed after allogeneic hematopoietic stem cell transplantation for PTLD.

Proliferaciones linforreticulares del pulmón / Pulmonary lymphoproliferative lesions

The present review describes the current classification of the pulmonary lymphoproliferative lesions as proposed by the WHO in 2004 with emphasis in the clinical picture and histopathological features. The definition of these entities includes the clinical picture, histopathology, immunohistochemistry and molecular features. The differential diagnosis of the most important entities is also briefly discussed

En el presente trabajo de revisión se describe la clasificación actual de las lesiones linfoproliferativas del pulmón propuesta por la OMS el año 2004 con énfasis en el cuadro clínico y los aspectos histopatológicos. La definición de estas entidades incluye cuadro clínico, histopatología, inmunohistoquímica y características moleculares. Se discute brevemente el diagnóstico diferencial de las formas más importantes

Enfermedades linfoproliferativas CD30 (+) de la piel / CD30-positive lymphoproliferative disorders of the skin

Las enfermedades linfoproliferativas CD30 (+) de la piel corresponden al grupo más común dentro de los linfomas cutáneos primarios de células T, después de la micosis fungoides. Este grupo incluye: papulosis linfomatoide, linfoma cutáneo primario de células grandes T CD30(+) (anaplástico), linfoma de células T CD30(+) con compromiso nodal regional y el linfoma cutáneo de células T CD30(+) secundario. Entre estas condiciones existe una sobreposición clínica, histológica e inmunofenotípica. La mayoría de los pacientes con esta condición tienen excelente pronóstico. Este artículo revisa los conocimientos actuales sobre estas condiciones con énfasis en diagnóstico y tratamiento.

Induction of macrophage killing of Leishmania donovani by human CD4+ T cell clones

Immunitary in leishmaniasis is mediated by T cells, but protective responses in humans have not been fully defined. In this study, the functional activity of CD4+ T cell clones derived from an immune individual was investigated to identify potentially protective responses. The T cells proliferated and produced interferon-gamma (IFN-gamma) in response to a soluble Leishmania donovani antigen extrac and live amastigotes. There was considerable variation in the anti-leishmanial activity of the T cell clones when they were co-cultured with L. donavani infected monocytes isolated from an HLA-DR,DQ mathced donor. All of the clones which demonstrated antigen specific reactivity by proliferation or cytokineproduction induced some dregee of inhibition of intracellular parasite replication, but only a few of the clones induced pronounced leishmanicidal activity. There was strong correlation between the level of amastigote-induced IFN-gamma secretion and anti-leishmanial activity. This approach anables the identification of potentially protective immune responses in humans at the clonal level, and offers a means for the identification of the relevant antigen(s)

Biologia e perfil imunológico das leucemias

Já está bem estabelecido que as leucemias são grupos heterogeneos de neoplasias tanto do ponto de vista clínico como de seus aspectos biológicos. Com o advento de técnicas imunológicas, demonstrou-se que as leucemias agudas são modelos ideais para pesquisas que levam ao conhecimento mais profundo do sistema hematopoiético. Reconhecendo o valor de uma abordagem multidisciplinar para classificar e investigar a origem da célula leucêmica, nós descrevemos neste trabalho os conceitos morfológicos, citoquímicos, imunológicos, citogenéticos e moleculares mais utilizados nos estudos dessas neoplasias. Inicialmente, fizemos uma revisão dos princípios básicos e dos elementos que constituem o sistema hematopoiético, bem como dos mecanismos que podem originar a transformação malígna de uma linhagem celular. Descrevemos as diferenciações antigênicas das linhagens linfóides e mielóides, bem corno a metodologia que detecta moléculas específicas de subtipos celulares. Finalmente, selecionamos dez artigos publicados nos quais estão descritos nossa experiência na identificação e classificação de leucemias agudas e síndromes linfoproliferativas, utilizando urna abordagem multidiscinlinar conforme mencionada acima.

Leukemia has been recognized to be a hetereogeneous malignant disorder, both clinically and biologically. Acute leukemias have been at the forefront of clinicotherapeutic research providing models for understanding hemopoietic system and kinetcs of cell differentiation and malignant transformation. Recognizing the value of a multidisciplinary approach to the investigation of leukemic cell origin, we have described a study that encompasses morphology, cytochemistry, immunophenotyping, cytogenetics and molecular biology to characterize acute and peripheral leukemias. First, we have reviewed several statements of the biological principles which have led to a further understanding of hemopoiesis and possible mechanisms of leukemogenesis. Then we have described the basic concepts of current methodology that has been suggested as new approaches together with frequently used techniques to diagnose and classify leukemias. Finally, we selcted ten consecutive papers, that were published, describing our experience to identify and characterize acute undifferentiated leukemias and lymphoproliferative disorders, through multidisciplinary approaches.