Characterization of nCD64 expression in neutrophils and levels of s-TREM-1 and HMGB-1 in patients with suspected infection admitted in an emergency department / Caracterización de la expresión de nCD64 en neutrófilos y de los niveles de s-TREM-1 y HMGB-1 en pacientes con sospecha de infección admitidos en el departamento de emergencias

Introduction: The nCD64 receptor, the soluble triggering receptor expressed in myeloid cells (s-TREM-1), and the high mobility group-box 1 protein (HMGB-1) have been proposed as significant mediators in sepsis. Objective: To evaluate the prognostic value of these markers in patients with suspected infection recently admitted in an emergency department (ED). Materials and methods: All patients who presented to the ED with suspected infection were eligible for enrollment in this study. Baseline clinical data, Sequential Organ Failure Assessment score (SOFA) score, APACHE II score, HMGB-1 levels, s-TREM-1 levels, and nCD64 levels were analyzed. The HMGB-1 and sTREM-1 serum concentrations were determined using commercially available ELISA kits, and CD64 on the surface of neutrophils was measured by flow cytometry. Results:. A total of 579 patients with suspected infection as their admission diagnosis were enrolled in this study. The median patient age was 50 years (IQR = 35-68). Morbidity during the 28-day followup period was 11.1% (n=64). The most frequent diagnosis at the time of admission was communityacquired pneumonia (CAP) in 23% (n=133) patients, followed by soft tissue infection in 16.6% (n=96), and urinary tract infection in 15% (n=87). After multivariable analysis, no significant association was identified between any biomarker and 28-day mortality. Conclusion: In the context of a tertiary care hospital emergency department in a Latin-American city, the nCD64 receptor, s-TREM-1, and HMGB-1 biomarkers do not demonstrate prognostic utility in the management of patients with infection. The search continues for more reliable prognostic markers in the early stages of infection.

Introducción. El receptor CD64, receptor soluble ´desencadenador´ expresado en células mieloides (sTREM-1) y la proteína del grupo Box-1 de alta movilidad (HMGB-1), se han propuesto como mediadores en la sepsis. Objetivo. Evaluar el valor pronóstico de estos marcadores en pacientes con sospecha de infección, recientemente admitidos en un departamento de emergencias. Materiales y métodos. Se incluyeron en el estudio pacientes que consultaron al hospital con sospecha de infección. Se analizó la base de datos clínica, el puntaje SOFA, el puntaje APACHE II, los niveles de HMGB-1, los niveles de sTREM-1 y los niveles de nCD64. Se determinaron las concentraciones en suero de HMGB-1 y sTREM-1, usando kits de ELISA disponibles comercialmente, y la de CD64 se midió por citometría de flujo. Resultados. Se analizaron 579 pacientes con sospecha de infección al ingreso. La edad media fue de 50 años (rango intercuartílico=35-68), y 11,1 % (n=64) murieron durante el seguimiento de 28 días. El diagnóstico más frecuente en el momento del ingreso fue neumonía adquirida en la comunidad, en 23 % (n=133) de los pacientes, seguida de infección de tejidos blandos, en 16,6 % (n=96), e infección urinaria, en 15 % (n=87). Después de un análisis multivariado, no hubo asociación significativa entre ningún biomarcador y la mortalidad a los 28 días. Conclusión. Los resultados sugieren que en el contexto de un departamento de emergencias de tercer nivel de una ciudad latinoamericana típica, los tres marcadores evaluados no ofrecieron ninguna ventaja en el pronóstico de infección. La búsqueda de marcadores pronósticos más confiables en estadios tempranos de la infección aún continúa abierta.

Delayed Human Neutrophil Apoptosis by Trichomonas vaginalis Lysate

Neutrophils play an important role in the human immune system for protection against such microorganisms as a protozoan parasite, Trichomonas vaginalis; however, the precise role of neutrophils in the pathogenesis of trichomoniasis is still unknown. Moreover, it is thought that trichomonal lysates and excretory-secretory products (ESP), as well as live T. vaginalis, could possibly interact with neutrophils in local tissues, including areas of inflammation induced by T. vaginalis in humans. The aim of this study was to investigate the influence of T. vaginalis lysate on the fate of neutrophils. We found that T. vaginalis lysate inhibits apoptosis of human neutrophils as revealed by Giemsa stain. Less altered mitochondrial membrane potential (MMP) and surface CD16 receptor expression also supported the idea that neutrophil apoptosis is delayed after T. vaginalis lysate stimulation. In contrast, ESP stimulated-neutrophils were similar in apoptotic features of untreated neutrophils. Maintained caspase-3 and myeloid cell leukemia-1 (Mcl-1) in neutrophils co-cultured with trichomonad lysate suggest that an intrinsic mitochondrial pathway of apoptosis was involved in T. vaginalis lysate-induced delayed neutrophil apoptosis; this phenomenon may contribute to local inflammation in trichomoniasis.

Enhanced neutrophil functions by recombinant human granulocyte colony-stimulating factor in diabetic patients with foot infections in vitro

This study was performed to evaluate the effect of granulocyte-colony stimulating factor on neutrophil functions in diabetic patients with active foot infections in vitro. Twelve diabetic patients with foot infections and 12 normal volunteers were enrolled. Neutrophils from peripheral blood were incubated with granulocyte colony-stimulating factor (G-CSF, 50 ng/mL) for 20 min. Superoxide production of neutrophils was measured by the reduction of ferricytochrome C. Neutrophil phagocytosis was assayed using Staphylococcus aureus and the weighted phagocytic index was calculated. Superoxide production of neutrophils in diabetic patients with foot infections was 7.7 (unit: nmol/2 x 10(5) cells/60 min), which was significantly lower than that in controls (12.0) (p<0.05). G-CSF increased neutrophil superoxide production to 12.1 in diabetic patients with foot infections and to 19.8 in controls (p<0.05 for each). Weighted phagocytic index in diabetic patients with foot infections was 0.77, which was not significantly different from that of the controls (0.69). Weighted phagocytic index was increased significantly by G-CSF to 0.88 in diabetic patients with foot infections and to 0.79 in controls (p<0.05 for each). In conclusion, G-CSF significantly enhanced neutrophil functions in diabetic patients with foot infections in vitro.

Peripheral blood lymphocyte subsets in patients with stomach cancer

The present study was conducted in order to investigate the immunologic alterations alongside the numerical changes in peripheral blood lymphocytes(PBL) and their subsets in stomach cancer patients. Lymphocyte surface markers were determined in 85 stomach cancer patients and 49 controls by indirect immunofluorescence technique using monoclonal antibodies. Monoclonal antibodies used were Leu 2a(CD8, suppressor/cytotoxic T cells), Leu 3a(CD4, inducer/helper T cells), Leu 4(CD3, pan T reagent), Leu 11(CD16, natural killer cells) and Leu 12(CD19, B cells). The numbers of PBL, CD3+, CD4+, CD8+, CD16+ and CD19+ cells significantly decreased and the CD4: CD8 value increased in 85 patients with stomach cancer compared to those in controls(p < 0.01). In stage I(n = 17), neither PBL, their subsets nor the CD4: CD8 value were significantly different from those of the controls. In stage II(n = 17), the numbers of PBL, CD3+, CD4+ and CD8+ cells decreased(p < 0.01). In stage III(n = 24) and IV(n = 27), PBL and all subsets measured decreased(p < 0.01). The CD4: CD8 value showed significant increases in stages III and IV(p < 0.01), because the CD8+ cells decreased to a greater extent than did the CD4+ cells. The results demonstrating that the lymphocyte subsets are depressed differentially with the stage suggest that host immunity is impaired with the progression of stomach cancer.

Protein uptake by cysticerci of Taenia Crassiceps

The internalization of host macromolecules to the vesicular fluid of T. crassiceps cysticerci was studied in vitro. Uptake of purified class G immunoglobulin was not significantly affected by the specificity of its antigen-recognition site and bovine serum albumin was internalized at a similar rate. Internalization was inhibited at low temperature, being optimal at 37ºC and saturation was accomplished only at a protein concentration in the culture medium over 12 mg/ml which is close to the physiological concentration of serum proteins in the host. Morphological studies using markers for adsorptive endocytosis allowed visualization of endocytic vesicles and tracking of their movement across the bladder wall tissue. Degradation of internalized proteins was observed at longer time of incubation, suggesting that proteins are later processed and that degraded host macromolecules can be nutrints for cysticerci. Quantification of this capability of internalization suggests that it might play a role in the in vivo removal of petentially damaging host macromelocules, such as antibodies or complement factors, from the host-prasite interface

Polymorphonuclear leukocyte functions enhanced by chemotaxis

Human polymorphonuclear leukocytes (PMN) migrate into tissues in response to chemoattractants, yet it is not known whether this process alters the functional capabilities of the PMN. Using recombinant human interleukin-8 (rHIL-8, 100 ng/ml) as a stimulus, we compared a population of PMN that migrated through a polyvinylpyrrolidone-coated polycarbonate filter containing 8.0 microns diameter pores with PMN stimulated in suspension. PMN were analyzed by flow cytometry according to functional and phenotypic criteria. CD11b/CD16 expression was unaltered by chemotaxis. In contrast, chemotaxis enhanced phagocytosis of E. coli, independent of opsonization with IgG. Similarly, chemotaxis increased baseline hydrogen peroxide production. We conclude that the chemotactic motion of PMN "primes" the cell for increased oxidative burst activity and augments the ability of PMN to ingest bacteria. This increased functional capability is distinct from rHIL-8 stimulation and appears to be independent of complement-and Fc-receptor expression.