ABSTRACT
La linfohistiocitosis hemofagocítica (HLH) es un síndrome clínico de hiperinflamación que se caracteriza por ser una respuesta inmune altamente estimulada pero inefectiva. En la HLH primaria se encuentran alterados el proceso de exocitosis de gránulos citotóxicos o los efectores que se encuentran en éstos, también existe afección de la activación de las células citotóxicas. Durante la exocitosis existe disfunción en la fase de transporte y maduración vesicular, en la regulación del proceso de docking y priming o en los complejos v-SNARE y t-SNARE. La conexión entre la célula citotóxica y célula diana se compromete si se afecta la proteína efectora perforina. SAP y XIAP se relacionan con la activación de las células inmunitarias. Aunque actualmente se conoce más de las moléculas que participan en la citotoxicidad, existe redundancia en las funciones de estas proteínas y aún quedan funciones que no han sido dilucidadas en dichos procesos.
Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome of hyperinflammation, in which the immune response is highly stimulated but it is ineffective. In primary HLH, the exocytosis process of cytotoxic granules or the effector proteins contained there are altered and the activation process of cytotoxic cells could be affected as well. During exocytosis there is dysfunction in vesicle maturation or translocation, in regulator proteins of the docking and priming process, or in v-SNARE and t-SNARE complexes. Connection between the cytotoxic cell and the target cell may be compromised if perforin effector protein is affected. SAP and XIAP have a role in the activation of immune cells. Though there is currently much known about the molecules participating in cytotoxicity, there is redundancy in protein functions involved in primary HLH, and there are some functions of these proteins that are still unknown.
A linfohistiocitose hemofagocítica (HLH) é uma síndrome clínica de hiperinflamação caracterizada por uma resposta imune que, apesar de ser altamente estimulada, é ineficaz. Na HLH primária, o processo de exocitose de grânulos citotóxicos, ou os efetores contidos neles, encontram-se alterados, também existe afecção na ativação das células citotóxicas. Existe disfunção na fase de transporte e amadurecimento vesicular, na regulação do processo de docking e priming, ou nos complexos v-SNARE e t-SNARE durante a exocitose. Caso a proteína efetora perforina estiver afetada, a conexão entre a célula citotóxica e a célula alvo está comprometida. SAP e XIAP estão relacionadas com a ativação das células imunitárias. Embora atualmente haja mais conhecimento a respeito das moléculas envolvidas na citotoxicidade, existe redundância nas funções destas proteínas. Contudo, ainda existem funções naqueles processos que não têm sido elucidadas até hoje.
Subject(s)
Humans , Animals , Lymphocyte Subsets/metabolism , Lymphohistiocytosis, Hemophagocytic , Lymphohistiocytosis, Hemophagocytic/immunology , Cytotoxins , Exocytosis/physiology , Killer Cells, NaturalABSTRACT
Hematological values, lymphocyte subsets and hematopoietic progenitor cells from normal term cord blood samples were studied, compared with normal adult blood, and analysed to determine whether a single collection of cord blood is sufficient for transplantation in adults. The parameters were assayed by automatic cells counter, flow cytometry and semisolid cell culture. All of the hematological values except RBC and MCHC were higher than in normal adult blood. Sex had an influence on RBC, Hb, Hct, Plt and reticulocyte counts. For lymphocyte subsets, all of the absolute CD3+, CD4+, CD8+ counts and T helper: suppressor ratio were higher than those of adult blood. All of the hematopoietic progenitor cells in cord blood were also higher than in adult blood. The mean volume of cord blood for each collection was 80.75 +/- 4.81 ml and the mean numbers of nucleated cells, CFU-GM and CD34+ were 13.51 +/- 0.38 x 10(8) cells, 4.33 +/- 0.66 x 10(5) colonies and 42.65 +/- 7.00 x 10(5) cells respectively. This 80 ml of cord blood would contain sufficient marrow repopulating cells for a recipient weighing about 20 kg. Recently developed technology, including ex vivo expansion may even permit transplants in adults.