Increased frequency of NK and gamma delta 1 T cells in a cohort of patients with sepsis * / Incremento en la frecuencia de células NK y células T gamma delta 1 en una cohorte de pacientes con sepsis

Introduction: The mechanisms involved in the immunopathogenesis of sepsis are not well established. The clinical and therapeutic relevance of several soluble mediators has been described and the contribution of cellular components with immunoregulatory roles has begun to be elucidated. Objective: To describe changes in the frequency and production of IFN- γ and IL-10 occurring in NK cells and γδ T lymphocytes in a cohort of patients with different manifestations of septic syndrome. Materials and methods: This was a prospective cohort study. Patients with sepsis (n=26), and severe sepsis (n=83) from adult emergency rooms and intensive care units, as well as healthy volunteers (n=8), were included. For all participants, the frequency and phenotype of NK cells and γδ T lymphocytes and the percentage of IFN- γ and IL-10 positive NK and γδ T cells were evaluated by flow cytometry. The NK cells were phenotyped based on the expression of CD56 and CD16 and the γδ T cells on the expression of d 1 and d 2 chains. Results: Patients with sepsis and severe sepsis exhibited an increase in the frequency of NK cells with changes in the proportion of the CD56 bright /CD16¯, CD56 bright /CD16 dim and CD56 dim CD16¯ subpopulations; these cells showed a proinflammatory cytokine profile. A decrease in the V d 2 subset of γδ T lymphocyte s was also observed. Conclusions: Our results indicate a role for NK and γδ T cells during sepsis, however, their exact contribution in the pathogenesis of sepsis syndrome requires further studies.

Introducción: Los mecanimos involucrados en la inmunopatogénesis de las sepsis no han sido claramente establecidos. La importancia clínica y terapéutica de diferentes mediadores solubles ha sido descrita y la contribución de componentes celulares con propiedades inmunorreguladoras ha empezado a dilucidarse. Objetivo: Describir los cambios en la frecuencia y en la producción de IFN- γ e IL-10 que se observa en células NK y linfocitos T γδ en una cohorte de pacientes con diferentes manifestaciones del síndrome séptico. Materiales y métodos: Estudio de cohorte prospectiva, donde pacientes con sepsis (n = 26) y sepsis grave (n = 83) provenientes de las salas de emergencias y unidades de cuidado intensivo, y controles sanos (n = 8) fueron incluidos. Tanto la frecuencia y fenotipo de las células NK y T γδ como el porcentaje de células IFN- γ+ e IL-10+ fueron evaluados mediante citometría de flujo. Las células NK fueron fenotipificadas con base en la expresión de las moléculas CD56 y CD 16 y los T γδ con base en la expresión de las cadenas δ1 y δ2. Resultados: En los pacientes con sepsis y sepsis grave se observó un incremento en la frecuencia de las células NK con cambios en las proporciones de las subpoblaciones CD56 bright /CD 16 ¯, CD56 bright /CD16 dim y CD56 dim CD16¯; en estas células se observó un perfil de citocinas proinflamarias. Se observó una reducción en el porcentaje de células Vδ2. Conclusiones: Los resultados sugieren un papel de las células NK y linfocitos T γδ durante la sepsis; sin embargo, su contribución en la patogénesis de este síndrome requiere estudios adicionales.

Células con propiedades inmunoreguladoras y su impacto en la patogénesis de la sepsis / Cells with immunoregulatory properties and their impact in the pathogenesis of sepsis

Sepsis, defined as a systemic inflammatory response syndrome caused by an infection, is a significant cause of mortality worldwide. It is currently accepted that death associated to sepsis is due to an immune hyperactivation state involving the development of a broad proinflammatory response along with alterations in the coagulation system. It is now clear that besides the inflammatory events, the clinical course of sepsis is characterized by the development of an anti-inflammatory response that could lead to death in its attempt to balance the initial response. The purpose of this review is to summarize current mechanisms that explain the pathogenesis of sepsis, underlying the role that cells with immunoregulatory properties play during the course of this complex syndrome. A better understanding of these processes will contribute in the search of more successful therapeutic strategies.

El síndrome de respuesta sistémica consecuencia de una infección, denominado sepsis, constituye una causa significativa de muerte en el mundo. Históricamente se ha aceptado que la muerte por sepsis se debe a un estado de hiperactivación inmunológica, que implica el desarrollo de una vasta respuesta pro-inflamatoria acompañada de alteraciones en el sistema de coagulación. Ahora es claro que además de los sucesos inflamatorios, el curso clínico de la sepsis se caracteriza por el desarrollo de una respuesta anti-inflamatoria que busca contrarrestar la respuesta inicial, y es ésta finalmente en gran parte responsable de la muerte de los pacientes. El propósito de esta revisión es resumir los mecanismos actuales que explican la patogénesis de la sepsis, y específicamente el papel que desempeñan las subpoblaciones celulares con propiedades inmuno-reguladoras durante el curso de la enfermedad. El mejor entendimiento de estos procesos contribuirá a la búsqueda de estrategias terapéuticas más exitosas.

Reproducibility of Total T Lymphocyte and Characterization of CD3(+)/CD4(-)/CD8(-) Lymphocyte in T Lymphocyte Subset Assay / 대한임상병리학회지

BACKGROUND: Total T lymphocytes can be measured by CD3-fluorescein isothiocyanate (FITC)/CD4-phycoerythrin (PE) and CD3-FITC/CD8-PE. The difference in the CD3 percentages between these two determinations was evaluated. And, we characterized the CD3(+)CD4(-)CD8(-) T lymphocytes subset using the monoclonal antibody that detects gamma delta T lymphocytes receptors. METHODS: The T lymphocyte subset assay was performed on 221 samples. A two-color direct immunofluorescence flow cytometric assay was done using a Simultest IMK-Lymphocyte kit (Bec-ton- Dickinson, San Jose, CA, USA). If the difference between the CD3 determinations were greater than 3%, the entire procedure was reviewed and the flow cytograms were reanalyzed. In 71 among 221 samples the proportion of gamma delta T lymphocytes was determined. RESULTS: The difference between the CD3-FITC/CD4-PE tube and CD3-FITC/CD8-PE tube was 3.0%, 3.6%, 3.0%, 3.4%, and 2.4% in normal subjects, patients with chronic liver disease, patients with cancer, patients with other diseases, and children, respectively. The between-tube differences for CD3 exceeding 3% were found in 69 samples (31.2%). The proportion of gamma delta T lymphocytes was 0.81%, 2.46%, 2.50%, and 0.85% in normal controls, patients with chronic liver disease, patients with cancer and patients with other diseases, respectively. No correlation between gamma delta T lymphocytes and CD3(+)CD4(-)CD8(-) T lymphocytes was observed. CONCLUSIONS: The reproducibility of the total T lymphocytes should be improved because of the between-tube difference exceeding 3% in about one third of the cases. Additionally, CD3(+)CD4(-)CD8(-) T lymphocytes were composed of heterogeneous subsets including gamma delta T lymphocytes and their proportion might be considered to be related to individual variation.