RESUMEN
BACKGROUND: Resistance training and protein supplementation are recommended strategies to combat sarcopenia. AIM: Quantification of muscle thickness (MT) by musculoskeletal ultrasound is a promising method to follow changes in skeletal muscles. The aim of this study was to investigate the effect of six months of resistance training with or without nutritional supplementation on MT of M. quadriceps in institutionalized old adults. DESIGN: This is a prospective, randomized, multi-arm parallel and controlled intervention study. SETTING: This study was conducted in five different retirement care facilities. POPULATION: Institutionalized individuals (mean age 82.6±6.2 years) were randomly assigned to an elastic band resistance training (N.=41), training with nutritional supplementation (N.=36) or control group (N.=40). METHODS: Health status and handgrip strength were investigated at baseline. MT of all parts of M. quadriceps of the left leg was assessed using musculoskeletal ultrasound at baseline and after six months. Linear regression models adjusted for age, BMI and sex were calculated to investigate the influence of baseline characteristics on MT. Multivariable regression analyses were performed for investigation of study intervention on MT. Follow-up examinations were performed after 12 and 18 months. RESULTS: Handgrip strength of both hands was significantly correlated with MT of M. vastus lateralis. Moreover, the sum of regularly taken medication was significantly correlated to MT of all parts of quadriceps. Six months of training or nutritional supplementation was not able to alter MT. However, participants with lower baseline MT values or a higher number of diseases and medications at baseline showed significant higher increases in MT after intervention. CONCLUSIONS: Resistance training using elastic bands with or without nutritional supplementation did not alter MT of M. quadriceps of old institutionalized individuals. However, baseline values and health status had a significant influence on the training effect. CLINICAL REHABILITATION IMPACT: As old individuals are very heterogenic according to their health and muscle status; further studies might focus on individualizing training regimes with particular emphasize on accompanied diseases and medications of this population.
Asunto(s)
Entrenamiento de Fuerza , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento , Suplementos Dietéticos , Fuerza de la Mano , Humanos , Fuerza Muscular/fisiología , Músculo Esquelético/diagnóstico por imagen , Músculo Esquelético/fisiología , Estudios Prospectivos , Entrenamiento de Fuerza/métodosRESUMEN
Moderate hyperhomocysteinemia is a well-established coronary risk factor that develops when dietary supply with folate and/or vitamin B(12) is inadequate. Recently, stimulated peripheral blood mononuclear cells were shown to produce homocysteine. Thus, the stimulated immune system may contribute to moderate hyperhomocysteinemia during certain diseases. Because multiple trauma and sepsis are accompanied by often strong inflammatory responses, we investigated whether hyperhomocysteinemia may develop in patients. Total homocysteine and cysteine concentrations were measured in 83 plasma specimens from 18 patients (14 men, 4 women; 15 posttrauma with sepsis and 3 with sepsis alone) every third day of follow-up. Finally results were compared with concentrations of cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6, the immune activation marker neopterin and the extent of tryptophan degradation as indicated by the kynurenine-to-tryptophan ratio (kyn/trp). Compared with baseline, average total homocysteine (P < 0.05, d 4-d 10) and cysteine (P < 0.05, d 7-d 13) concentrations increased during follow-up of patients. However, only the increase of homocysteine was related to the survival status: total homocysteine was significantly higher in nonsurvivors (P < 0.05, d 4 and d 10) than in survivors, whereas cysteine concentrations increased in both subgroups. Homocysteine correlated with kyn/trp but not with neopterin concentrations. Increase of total homocysteine is common in patients after trauma with unfavorable outcome. Because all patients received standardized enteral nutrition after the end of hypodynamic shock, inconsistent vitamin supply is unlikely to be the reason for hyperhomocysteinemia in some of the patients; rather, it is associated with a stronger proinflammatory response. Certainly, the number of patients in our study is still small and results can only be regarded as preliminary.
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Homocisteína/sangre , Hiperhomocisteinemia/inmunología , Sepsis/complicaciones , Sepsis/terapia , Adulto , Biomarcadores/sangre , Femenino , Estudios de Seguimiento , Humanos , Hiperhomocisteinemia/metabolismo , Interleucina-6/sangre , Quinurenina/sangre , Masculino , Persona de Mediana Edad , Neopterin/sangre , Resultado del Tratamiento , Triptófano/sangre , Factor de Necrosis Tumoral alfa/sangre , Adulto JovenRESUMEN
Immune dysfunction in trauma patients is associated with immune system activation and inflammation. The cytokine-inducible enzyme IDO (indoleamine 2,3-dioxygenase) initiates the degradation of the essential aromatic amino acid tryptophan via the kynurenine pathway and could contribute to deficient immune responsiveness. Activated IDO is indicated by an increased kyn/trp (kynurenine/tryptophan) ratio. The aim of the present study was to investigate whether tryptophan degradation is associated with outcome in patients post-trauma. Tryptophan and kynurenine concentrations were measured by HPLC in serum specimens of 15 patients post-trauma during 12-14 days of follow-up. Up to five samples within this observation period from each patient were included in this analysis, and a total a 69 samples were available. For further comparisons, concentrations of the immune activation marker neopterin were measured. Compared with healthy controls, the average kyn/trp ratio and kynurenine concentrations were increased in patients, whereas tryptophan concentrations were decreased. During follow-up, increased kyn/trp ratio and kynurenine concentrations (all P<0.001) were observed, whereas the changes in tryptophan concentrations were not significant. Non-survivors had higher kyn/trp ratios and kynurenine concentrations compared with survivors. The kyn/trp ratio correlated with neopterin concentrations (r(s)=0.590, P<0.001). In conclusion, these results imply that increased tryptophan degradation in patients is due to activated IDO, which most probably is a consequence of a host defence response. These findings support a possible role for IDO in the development of immunodeficiency and death in patients.
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Traumatismo Múltiple/sangre , Triptófano/sangre , Adulto , Anciano , Biomarcadores/sangre , Métodos Epidemiológicos , Femenino , Humanos , Indolamina-Pirrol 2,3,-Dioxigenasa/sangre , Indolamina-Pirrol 2,3,-Dioxigenasa/fisiología , Quinurenina/sangre , Masculino , Persona de Mediana Edad , Traumatismo Múltiple/inmunología , Pronóstico , Adulto JovenRESUMEN
BACKGROUND AND AIMS: Tertiary peritonitis is a severe persisting intra-abdominal infection and associated with high mortality. The aim was to find significant risk factors for mortality and tertiary peritonitis including the Mannheim Peritonitis Index (MPI), the Acute Physiology and Chronic Health Evaluation (APACHE) II score, and a sumscore of both. MATERIALS AND METHODS: In this retrospective single-center cohort study, 122 patients were treated at the Surgical Department of a University Hospital. RESULTS: Sixty-nine patients (56.6%) developed tertiary peritonitis. Nineteen patients (27.5%), who suffered from tertiary peritonitis, died in contrast to eight patients (15.1%) with secondary peritonitis (P = 0.101). Patients with tertiary peritonitis had significantly higher APACHE II (P < 0.001), MPI (P = 0.035), and combined APACHE II and MPI scores (P < 0.001) than patients with secondary peritonitis. Age (P = 0.035), fungal infections (P = 0.025), and infections with more than one microbial organism (P = 0.047) were predictive for tertiary peritonitis. Combined APACHE II and MPI scores detected tertiary peritonitis better than the MPI (P = 0.014). Detection of mortality was comparable in all evaluated prognostic scores. CONCLUSION: Prognostic scores besides age and fungal infections are risk factors for mortality and help to differentiate between secondary and tertiary peritonitis. The combination of prognostic scores is comparable to the APACHE II and superior compared to the MPI in regard to detection of tertiary peritonitis.
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APACHE , Infecciones Bacterianas/mortalidad , Infecciones Bacterianas/cirugía , Peritonitis/mortalidad , Peritonitis/cirugía , Índice de Severidad de la Enfermedad , Adulto , Factores de Edad , Anciano , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , Técnicas Bacteriológicas , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Peritonitis/diagnóstico , Peritonitis/microbiología , Pronóstico , Curva ROC , Recurrencia , Reoperación , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
BACKGROUND: Former athletes who continue a regular, performance-oriented training throughout life provide a unique model for studying successful aging. With this in mind, the current study aimed to compare the effects of an acute resistance exercise on proteolytic and myogenic markers in older weightlifters and untrained participants. METHODS: Sixteen older men (8 former weightlifters, 8 age-matched untrained controls) with an age of 61.2±8.2 years volunteered to participate in the study. Two days after assessing 1-RM, an acute exercise protocol (3 sets, 70-75% of one-repetition maximum until voluntary fatigue) was applied unilaterally on the dominant leg while the other leg served as control. Three hours after termination of the exercise, skeletal muscle tissue was obtained from m. vastus lateralis of both legs. RESULTS: Acute resistance exercise led to an up-regulation (>1.5-fold) of 14 genes in controls and of 13 genes in weightlifters. The transcription factors FOS and early growth response 1 (EGR1), as well as the E3 protein ligase TRIM63 comprised the most responsive genes to resistance exercise (EGR1:15.7-fold increase, P=0.003, FOS: 36.3-fold increase, P<0.001; TRIM63: 2.9-fold increase, P<0.001). In addition, myostatin levels were decreased in the exercised leg (0.6-fold, P<0.001). FOXO3 gene expression was significantly higher in weightlifters than in untrained controls (1.5-fold, P=0.042). CONCLUSIONS: Trained and untrained older adults respond to an acute bout of resistance exercise in a very similar way irrespective of training status, although some differences exist in FOXO3, potentially reflecting the superior capacity of trained persons in regulating cellular homeostasis.
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Ejercicio Físico , Miostatina/genética , Músculo Cuádriceps/metabolismo , Entrenamiento de Fuerza , Anciano , Biomarcadores/metabolismo , Estudios de Casos y Controles , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Miostatina/metabolismo , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas de Motivos Tripartitos/genética , Proteínas de Motivos Tripartitos/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
BACKGROUND: Age related loss of skeletal muscle mass is accompanied by changes in muscle quality leading to impairment of functional status. AIM: This study investigated the effect of resistance training and nutritional supply on muscle mass and muscle quality in very old institutionalized adults. DESIGN: Prospective, randomized, multi-arm parallel and controlled intervention study. SETTING: This study was conducted in five retirement care facilities. POPULATION: This subgroup of the Vienna Active Ageing Study included 54 women and men (82.4±6.0 years) with impaired health status. Participants were randomly assigned either to elastic band resistance training (N.=16), training with nutritional supplementation (N.=21) or control group (N.=17). METHODS: Health status was assessed at baseline with functional tests, cognitive status, nutritional status, sum of medications as well as sum of diseases. Skeletal muscle mass, determined by dual-energy X-ray absorptiometry, isokinetic knee extension and flexion force and handgrip strength were assessed at baseline and after 6 months. Muscle quality of lower extremities was defined as ratio of the extensor (MQ_LE (Ext.)) or flexor strength (MQ_LE (Flex.)) to lean leg mass. Muscle quality of upper extremity was defined as ratio of handgrip strength to lean arm mass. Follow-up examinations were performed after 12 and 18 months of intervention. RESULTS: Muscle quality, but not muscle mass, showed significant correlations to functional tests at baseline (0.300 - 0.614, P<0.05). Resistance training significantly enhanced muscle quality of lower extremity after 6 months (MQ_LE (Ext.) +19.8%, MQ_LE (Flex.) +30.8%, P<0.05). Nutritional supplementation could not further increase the training effect. Participants with lower muscle quality at baseline benefit most from the training intervention. Skeletal muscle mass was not changed by any intervention. CONCLUSIONS: Resistance training with elastic bands improved muscle quality in very old people. Additional nutritional supplementation was not able to further improve the effects obtained by training alone. CLINICAL REHABILITATION IMPACT: Elastic band resistance training could be safely used to improve muscle quality even in old people with impaired health status. Weak and chronically ill participants benefit most from this training.
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Composición Corporal , Institucionalización , Fuerza Muscular/fisiología , Músculo Esquelético/fisiopatología , Entrenamiento de Fuerza , Sarcopenia/prevención & control , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Cuidados a Largo Plazo , Masculino , Músculo Esquelético/patologíaRESUMEN
BACKGROUND: Liver transplantation for nonresectable liver metastases from colorectal cancer was abandoned in 1994 on account of high recurrence rates. The aim of this study was to investigate whether the genetic detection of micrometastases in histologically negative lymph nodes of the primary colon cancer could be applied to select patients for liver transplantation. METHODS: We analyzed 21 patients with colorectal cancer who had undergone liver transplantation between 1983 and 1994 for liver metastases. Eleven patients were histologically lymph node negative at the time of surgery; ten patients with lymph node metastases served as control group. DNA sequencing was used to screen tumor material for p53 and K-ras mutations. Mutant allele-specific amplification (MASA) was then used to search for micrometastases in DNA from regional lymph nodes of the primary colorectal cancer. RESULTS: p53 and K-ras mutations were detected in 12 (57%) and 3 (14%) of 21 patients in the colorectal cancer, respectively. The mutations were confirmed in the corresponding liver metastases. Of 11 patients with histologically negative lymph nodes, nine were eligible for MASA due to presence of p53 or K-ras mutation. MASA revealed six of nine patients to be genetically positive for micrometastases. Three patients were both genetically and histologically negative. These three patients showed a significantly longer overall survival (P = 0.011) of 4, 5, and 20 years, respectively. CONCLUSIONS: We conclude that the genetic detection of micrometastases by MASA could be a powerful prognostic indicator for selecting patients with colorectal liver metastases who could benefit from liver transplantation.
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Neoplasias Colorrectales/patología , Neoplasias Hepáticas/secundario , Neoplasias Hepáticas/cirugía , Trasplante de Hígado , Metástasis Linfática/diagnóstico , Metástasis Linfática/genética , Adulto , Secuencia de Bases , Neoplasias Colorrectales/genética , Femenino , Humanos , Neoplasias Hepáticas/genética , Metástasis Linfática/patología , Masculino , Persona de Mediana Edad , Mutación/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Tasa de Supervivencia , Proteína p53 Supresora de Tumor/genéticaRESUMEN
Multiple trauma patients have an impaired immune system and thus frequently develop life-threatening septic complications. Because there is an ongoing debate on which are the most predictive immunologic parameters of clinical outcome, we prospectively studied 19 multiple trauma patients with sepsis (mean age, 38.7 +/- 15.8 years; mean Injury Severity Score, 40.6 +/- 11.6) over a period of 14 days. The following parameters were measured daily after admission to the intensive care unit: ex vivo lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-alpha) production, monocyte human leukocyte antigen (HLA)-DR expression, constitutive interleukin (IL) 6 secretion, white blood cell count, and C-reactive protein. In addition, procalcitonin, neopterin, LPS-binding protein, and constitutive TNF-alpha secretion were measured every third day. Immediately after trauma, all patients had significantly lower levels of HLA-DR and ex vivo LPS-stimulated TNF-alpha secretion than healthy controls (n = 7; P < 0.001). On the day after clinical diagnosis of sepsis, before any other parameter differed between survivors (n = 13) and nonsurvivors (n = 6), ex vivo LPS-induced TNF-alpha secretion was significantly lower (P < 0.05) in nonsurvivors than in survivors. We conclude that ex vivo LPS-induced TNF-alpha production is an earlier predictor of clinical outcome in multiple trauma patients with sepsis than monocyte HLA-DR expression, constitutive IL-6 secretion, or any other parameter assessed.
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Regulación de la Expresión Génica/efectos de los fármacos , Antígenos HLA-DR/biosíntesis , Lipopolisacáridos/farmacología , Monocitos/metabolismo , Traumatismo Múltiple/metabolismo , Sepsis/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Sanguíneas/biosíntesis , Células Cultivadas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Monocitos/patología , Traumatismo Múltiple/complicaciones , Traumatismo Múltiple/mortalidad , Traumatismo Múltiple/patología , Evaluación de Resultado en la Atención de Salud , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sepsis/etiología , Sepsis/mortalidad , Sepsis/patologíaRESUMEN
There is a high need for blood-based biomarkers detecting age-related changes in muscular performance at an early stage. Therefore, we investigated whether serum levels of growth and differentiation factor-15 (GDF-15), activin A, myostatin, follistatin, and insulin-like growth factor-1 (IGF-1) would reflect age- and physical performance-related differences between young (22-28 years) and elderly (65-92 years) females. Isokinetic peak torque of knee extension (PTE) was measured in young females to obtain reference values for the discrimination of different stages of age-associated muscle weakness. Additionally, elderly women were screened for sarcopenia using the algorithm of the European Working Group on Sarcopenia in Older People (low muscle mass in addition to low PTE and/or low walking speed). IGF-1 levels were higher and GDF-15 levels were lower in young females in comparison to the elderly (p < 0.01), whereas members of the activin A/myostatin/follistatin axis showed similar levels across age groups. In older women, IGF-1 correlated negatively with age (ρ = -0.359, p < 0.01) and positively with muscle mass (ρ = 0.365, p < 0.01). In contrast, GDF-15 correlated positively with age (ρ = 0.388, p < 0.001) and negatively with muscle mass (ρ = -0.320, p < 0.01). However, none of the serum markers differed between women classified as non-, mildly and severely dynapenic/sarcopenic. Multiple linear regression analyses revealed that a combination of all blood-based biomarkers obtained in addition to age and fat mass moderately predicted muscle mass (+2.9%). Neither a single nor a combined set of tested biomarkers reflected the presence of dynapenia or sarcopenia in elderly women. However, due to the associations of IGF-1 and GDF-15 with correlates of muscle mass and function, these parameters remain promising candidates in a potential set of blood-based biomarkers to diagnose sarcopenia and/or dynapenia.
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Folistatina/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , Atrofia Muscular/diagnóstico , Sarcopenia/diagnóstico , Proteínas de la Superfamilia TGF-beta/sangre , Activinas/sangre , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Austria , Biomarcadores/sangre , Composición Corporal , Comorbilidad , Femenino , Factor 15 de Diferenciación de Crecimiento/sangre , Humanos , Atrofia Muscular/sangre , Miostatina/sangre , Examen Físico , Análisis de Regresión , Sarcopenia/sangre , Adulto JovenRESUMEN
Toll-like receptors (TLR) play a pivotal role in the innate immune response, and the expression levels of these receptors may reflect the sensitivity of immune cells to infections. The binding of lipopolysaccharide (LPS) to TLR-4 triggers human monocytes to produce cytokines, which play a dominant role in the inflammatory response, as can be observed during sepsis and after polytrauma. Here, we evaluated TLR-4 expression of isolated monocytes in the presence of tumor necrosis factor (TNF)-alpha, interleukin (IL) 6, IL-8, and IL-10, and we investigated cellular activation of this treatment. TNF-alpha significantly down-regulated TLR-4 mRNA expression after 6 h (100% vs. 38.5% +/- 4%; P < 0.05). This down-regulation was followed by a dose- and time-dependent diminished expression of TLR-4 surface protein (100% vs. 8.0% +/- 5%; P < 0.01). Forty-eight hours after TNF-alpha treatment, a reduced nuclear factor (NF)-kappaB translocation and a diminished IL-6 secretion after LPS stimulation were found (100% vs. 42.0% +/- 23%; P < 0.05). In contrast, IL-6 incubation upregulated TLR-4 cell surface protein (100% vs. 165.8% +/- 24%; P < 0.05) and increased the ability to activate NF-kappaB and AP-1 after LPS stimulation. Stimulation with IL-8 or IL-10 had no significant effects. We conclude that not only LPS but also TNF-alpha and IL-6 have the potency to regulate the immune response via TLR-4. Down-regulation of TLR-4 by TNF-alpha is associated with LPS hyporeactivity for NF-kappaB formation, whereas upregulation of TLR-4 via IL-6 can increase the responsiveness of mononuclear phagocytes.
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Interleucina-6/metabolismo , Lipopolisacáridos/metabolismo , Glicoproteínas de Membrana/biosíntesis , Monocitos/metabolismo , Receptores de Superficie Celular/biosíntesis , Factor de Necrosis Tumoral alfa/metabolismo , Transporte Biológico , Núcleo Celular/metabolismo , Células Cultivadas , Citocinas/metabolismo , ADN/metabolismo , ADN Complementario/metabolismo , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Citometría de Flujo , Humanos , Inflamación , Interleucina-10/metabolismo , Interleucina-8/metabolismo , Leucocitos Mononucleares/metabolismo , FN-kappa B/metabolismo , Fagocitos/metabolismo , Unión Proteica , ARN/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sepsis , Factores de Tiempo , Receptor Toll-Like 4 , Receptores Toll-LikeRESUMEN
Apoptosis of the epithelium is deemed to play a pivotal role in the pathogenesis of sepsis. A neoepitope in cytokeratin 18 (CK18), termed M30 neoantigen, becomes available at an early caspase cleavage event during apoptosis of epithelium-derived cells and is not detectable in vital or necrotic epithelial cells. A monoclonal antibody, M30, specifically recognizes a fragment of CK18 cleaved at Asp396 (M30 neoantigen). We used an enzyme-linked immunosorbent assay (ELISA) to measure M30 antigen levels in the sera of 15 septic patients. Healthy humans and critical ill patients suffering from severe trauma served as controls. Mann-Whitney U test was used to calculate significance, and a P value of <0.01 was considered to be statistically significant. Serum levels of the CK18 neoepitope M30 were significantly increased in septic patients (236.88 +/- 47.4 U/L) versus trauma (97.2 +/- 17.1 U/L) and healthy controls (66.9 +/- 9.2 U/L) (P < 0.01 and P < 0.008, respectively). The increased serum level of the CK18 neoepitope in septic patients indicates a heightened apoptotic turnover in epithelial cells as compared with trauma patients and healthy controls. Interestingly, nonsurviving trauma patients exhibited a significant increase in the M30 neoantigen as compared with survivors and healthy controls (P < 0.003 and P < 0.002, respectively). The detection of CK18 neoepitope M30 in the serum might be a useful marker in tracing apoptotic epithelium in septic patients.
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Epítopos/sangre , Queratinas/sangre , Sepsis/sangre , Heridas y Lesiones/sangre , Adulto , Biomarcadores/sangre , Femenino , Humanos , Queratinas/inmunología , Masculino , Persona de Mediana Edad , Valores de Referencia , Estudios RetrospectivosRESUMEN
Immune system activation and inflammation accompanies immune dysfunction in trauma and sepsis patients. Immunodeficiency may develop in such patients as one consequence of an activated chronic pro-inflammatory response. According to recent data, degradation of L-tryptophan (TRP) via the kynurenine (KYN) pathway by the cytokine-inducible enzyme indoleamine 2,3-dioxygenase (IDO) could represent an important contributor to the deficient responsiveness of immunocompetent cells. Compared to healthy controls, patients post trauma or with sepsis had increasing KYN concentrations and KYN to TRP ratios (KYN/TRP) whereas TRP concentrations decreased. Likewise, concentrations of cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and of immune activation marker neopterin increased in patients (all p < 0.001). Furthermore in patients KYN/TRP, KYN and neopterin concentrations were further increasing (all p < 0.001), whereas the changes of TRP, TNF-α and IL-6 concentrations were not significant. Compared to the survivors, the non-survivors had a higher concentration of KYN, neopterin, TNF-α and IL-6 as well as a higher KYN/TRP ratio. KYN/TRP correlated with neopterin (p < 0.001) and also with TNF-α (p < 0.01) and IL-6 concentrations (p < 0.05) and inversely with the in vitro response of stimulated monocytes. We conclude that increased TRP degradation in patients post trauma is closely associated with immune activation. Cytokines released during the pro-inflammatory response may induce the activity of IDO and thus accelerate TRP degradation. Thus, increased IDO activity most likely represents a result of host response to pro-inflammation in patients. Data support a possible role of inflammation-induced IDO in the diminished immunoresponsiveness in patients.
RESUMEN
Toll-like receptors (TLR) represent an ancient front-line defence system that enables the host organism to sense the presence of microbial components within minutes. As inducers of inflammation, TLR act as important triggers of distinct entities such as sepsis or autoimmune disease exacerbation. We report here that vitamin D3 [1alpha,25-dihydroxycholecalciferol, 1,25(OH)(2)D3] suppresses the expression of TLR2 and TLR4 protein and mRNA in human monocytes in a time- and dose-dependent fashion. Despite 1,25(OH)(2)D3-induced up-regulation of CD14, challenge of human monocytes with either LPS or lipoteichoic acid resulted in impaired TNF-alpha and procoagulatory tissue factor (CD142) production, emphasizing the critical role of TLR in the induction of inflammation. Moreover, reduced TLR levels in 1,25(OH)(2)D3-treated phagocytes were accompanied by impaired NF-kappaB/RelA translocation to the nucleus and by reduced p38 and p42/44 (extracellular signal-regulated kinase 1/2) phosphorylation upon TLR-ligand engagement. Both TLR down-regulation and CD14 up-regulation were substantially inhibited by the vitamin D receptor (VDR) antagonist ZK 159222, indicating that the immunomodulatory effect of 1,25(OH)(2)D3 on innate immunity receptors requires VDR transcription factor activation. Our data provide strong evidence that 1,25(OH)(2)D3 primes monocytes to respond less effectively to bacterial cell wall components in a VDR-dependent mechanism, most likely due to decreased levels of TLR2 and TLR4.