RESUMEN

The risk of mortality is high in burn patients and correlates with age, burn area extent, and sepsis. Immunosuppression has been reported to occur after severe burn. Cytotoxic cells possess specialized granules containing perforin and a group of serine proteases (granzymes). Granzyme A is a serine protease constitutively expressed by gammadelta and NK cells, in agreement with their functional cytolytic potential. In vitro studies have shown that GrA may be released extracellularly during cytotoxic cell degranulation, indicating the activation of cytotoxic cells. The aim of our study was to determine plasma GrA activity in burned patients and to verify if decreased GrA levels were associated with poor prognosis. Specific GrA activity was tested in the plasma of burned and healthy subjects by esterase assay. Plasma GrA was significantly decreased in septic rather than in nonseptic burn patients and in healthy subjects (p < 0.05 and p < 0.001, respectively). At day 3 plasma GrA was significantly lower in nonsurvivor than in survivor septic patients (p < 0.05). The value of 91 mOD showed a sensitivity of 100% and a specificity of 84% in differentiating survivor from nonsurvivor septic patients. Because this is a retrospective study, Granzyme A is not a confirmed predictor of septic outcome after burn, but its determination could give useful information about the development and severity of sepsis.

Asunto(s)

Quemaduras/sangre , Granzimas/sangre , Sepsis/sangre , Adulto , Anciano , Antibacterianos/uso terapéutico , Biomarcadores/sangre , Quemaduras/complicaciones , Quemaduras/enzimología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Sepsis/diagnóstico , Sepsis/tratamiento farmacológico

RESUMEN

Burns are associated with immune suppression and subsequent development of sepsis. Dendritic cells (DCs) are potent antigen-presenting cells that serve as a critical link between the innate and acquired immune systems, and are essential in coordinating the host response to pathogens. Using multicolour flow cytometry, the percentages of LIN(-) DR(+) CD11c(+) myeloid (mDC) and LIN(-) DR(+) CD123(+) plasmacytoid (pDC) subsets were determined in peripheral blood from 32 people (15 septic and 5 non-septic burn victims and 12 age- and gender-matched healthy controls, up to 20 days from injury). Analysis revealed significant reductions in circulating mDCs and pDCs in survivor as well as non-survivor septic cases compared with non-septic cases and controls (p<0.001). These findings suggest that deficiencies in mDCs and pDC subsets are related to sepsis following severe burn, and may contribute to immunosuppression among burn victims.

Asunto(s)

Células Presentadoras de Antígenos/citología , Quemaduras/inmunología , Células Dendríticas/inmunología , Células Mieloides/inmunología , Sepsis/inmunología , Adulto , Factores de Edad , Células Presentadoras de Antígenos/inmunología , Quemaduras/mortalidad , Estudios de Casos y Controles , Separación Celular , Células Dendríticas/citología , Femenino , Citometría de Flujo , Humanos , Inmunidad Celular , Masculino , Persona de Mediana Edad , Células Mieloides/citología , Sepsis/mortalidad

RESUMEN

The body's immunological response to burn injury has been a subject of great inquiry in recent years. Burn injury disturbs the immune system, resulting in a progressive suppression of the immune response that is thought to contribute to the development of sepsis. Dendritic cells (DCs) are potent antigen-presenting cells that possess the ability to stimulate naïve T cells.DCs are derived from bone marrow progenitors and circulate in the blood as immature precursors prior to migration into peripheral tissues. Within different tissues, DCs differentiate and become active in the taking up and processing of antigens, and their subsequent presentation on the cell surface is linked to major histocompatibility molecules. Upon appropriate stimulation, DCs undergo further maturation and migrate to secondary lymphoid tissues, where they present antigen to T cells and induce an immune response. The purpose of this study was to determine the effects of burn injury on skin DCs in terms of percentage, HLA-DR, and Toll-like receptor-4 (TLR-4) expression. The skin DCs were isolated from burned skin and non-burned skin in the same patient at 7 days post-injury, and skin DCs were isolated from unburned healthy individuals as control. DCs from burned skin notably express low levels of HLA-DR and TLR-4 soon after cell isolation. In the post-burn period the ability of skin DCs to respond to bacterial stimuli is impaired. These changes in DC behaviour might contribute to the impaired host defences against bacteria during burn sepsis.

RESUMEN

The results are presented of the local treatment of burns with honeycomb expanded polyurethane. This method of treatment can be used both for the medication of burns of limited extent but variable depth and as a mattress for patients confined to bed. In the first case, the purpose of the treatment, which makes use of the product's absorbent and debriding capacity, is either to cure the lesion or to pave the way for the surgical operation. In the second case use is made of the product's exudate-draining and anti-pressure sore activity, which prevents the lesion from becoming deeper.

RESUMEN

Burn injury induces a suppression of the Th1 response, which is associated with an increased susceptibility to conditions of infection, morbidity, and mortality. It is well established that cytokines modulate the pathogenesis of burn injury. In this study, plasma levels of interleukin-6 (IL-6) and interleukin-10 (IL-10) were determined in burn patients and correlated with the severity of sepsis. Sixty adult burn patients (total body surface area burned, 8-80%) were included in the study, of whom 34 developed sepsis and 14 died. The nonseptic group consisted of 26 patients. Thirty-one healthy blood donors served as controls. Patients were not treated with antibiotics until sepsis occurred. Plasma samples were collected immediately post-burn and after several days, and cytokine concentrations were determined by ELISA. Within three days, all the patients presented high levels of circulating IL-6, which were significantly higher in septic patients than in nonseptic patients (349 ± 278 vs 63 ± 56 pg/ml, p < 0.001).IL-10 levels were higher in septic patients than in nonseptic patients at all times in our study. The value of 60 pg/ml shows a sensitivity of 92% and a specificity of 93% in the differentiation of survivor from nonsurvivor septic patients. In this study the high value of circulating IL-10 on day 3 suggests that cytokine may discriminate between nonsurvivor septic and survivor septic patients.

RESUMEN

Burn injury is associated with immune suppression and the subsequent development of sepsis. Severe burn injury is associated with depressed immune response, including a functional impairment of Th1 lymphocytes and natural killer cells and a decrease in interferon-a production. Dendritic cells (DCs) are potent antigen-presenting cells and play a key role in T cell activation; they are essential in coordinating the host response to pathogens. Using three-colour flow cytometry, we determined the percentage of lineage-negative LIN-DR+ DCs in burn patients and healthy subjects. The percentages of DCs were lower in the circulation of septic than in nonseptic patients and healthy subjects at all times examined (14 days) after burn injury. In contrast, the DC percentage in nonseptic patients was low at day 1, increased from day 3 to day 10, and reverted to normal levels at day 14. The data from the present study suggest that the DC percentage decreased early after burn injury. In addition, in the presence of severe sepsis, the DC percentage remained lower until day 14. This DC reduction may contribute to the immunosuppression observed after burn injury.

RESUMEN

In view of the pathogenic mechanisms of Lyell's syndrome, we consider support-only treatment to be insufficient and believe it is necessary to administer i.v. human immunoglobulin. Because of the potentially severe side effects of the high doses usually recommended, we prefer to use low doses (no more than 5 g per day) in association with the administration of fresh frozen plasma, which offers the benefits of the high protein content in the albumin (with its resuscitatory function) and its globulin content (functioning as a specific therapy for Lyell's syndrome). We present the latest cases we have observed and treated using this protocol.

RESUMEN

A case is presented of pyoderma gangrenosum, describing its characteristic features with particular reference to the phenomenon of pathergy, which considerably limits the surgical approach to the disease. After an account of the numerous skin ulcerations that have to be taken into consideration in order to make a differential diagnosis, it is noted that pyoderma gangrenosum can only on rare occasions be confused with a full-thickness granulating burn.

RESUMEN

A review of the relative international literature of the last few years is followed by a description of two cases of staphylococcal scalded skin syndrome in adults. As in both cases the initial diagnosis was that of Lyell's syndrome, the main criteria for the differential diagnosis of the two pathologies are considered in order to permit specific and effective treatment.

RESUMEN

After presenting an analysis of the principal antiseptics used for the local treatment of burns, highlighting their toxicity and the limitations of their antibacterial effectiveness, we describe the therapeutic protocol used in our burns centre (where antibacterial treatment consists exclusively of antibiotics for both local and systemic use). We review the data regarding actual and predicted mortality, and mortality due to septicaemia during the years 2000-2003.