Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
JACC Case Rep ; 18: 101921, 2023 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-37545677

RESUMEN

A 46-year-old man with a personal history of a repaired aortic dissection was admitted because of hemolytic anemia. The transesophageal echocardiogram displayed an accelerated flow and a residual intimal flap in the proximal descending aorta. A total arch replacement was performed, the flap was removed, and his hemolytic anemia was resolved. (Level of Difficulty: Advanced.).

2.
Heart ; 110(1): 40-48, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37414523

RESUMEN

OBJECTIVE: We sought to investigate prevalence, incidence and prognostic implications of permanent pacemaker (PPM) implantation in patients with cardiac amyloidosis (CA), thereby identifying the predictors of time to PPM implantation. METHODS: Seven hundred eighty-seven patients with CA (602 men, median age 74 years, 571 transthyretin amyloidosis (ATTR), 216 light-chain amyloidosis (AL)) evaluated at two European referral centres were retrospectively included. Clinical, laboratory and instrumental data were analysed. The associations between PPM implantation and mortality, heart failure (HF) or a composite endpoint of mortality, cardiac transplantation and HF were analysed. RESULTS: 81 (10.3%) patients had a PPM before initial evaluation. Over a median follow-up time of 21.7 months (IQR 9.6-45.2), 81 (10.3%) additional patients (18 with AL (22.2%) and 63 with ATTR (77.8%)) underwent PPM implantation with a median time to implantation of 15.6 months (IQR 4.2-40), complete atrioventricular block was the most common indication (49.4%). Independent predictors of PPM implantation were QRS duration (HR 1.03, 95% CI 1.02 to 1.03, p<0.001) and interventricular septum (IVS) thickness (HR 1.1, 95% CI 1.03 to 1.17, p=0.003). The model to estimate the probability of PPM at 12 months and containing both factors showed a C-statistic of 0.71 and a calibration of slope of 0.98. CONCLUSIONS: Conduction system disease requiring PPM is a common complication in CA that affects up to 20.6% of patients. QRS duration and IVS thickness are independently associated with PPM implantation. A PPM implantation at 12 months model was devised and validated to identify patients with CA at higher risk of requiring a PPM and who require closer follow-up.


Asunto(s)
Neuropatías Amiloides Familiares , Estenosis de la Válvula Aórtica , Bloqueo Atrioventricular , Marcapaso Artificial , Masculino , Humanos , Anciano , Estudios Retrospectivos , Marcapaso Artificial/efectos adversos , Bloqueo Atrioventricular/diagnóstico , Bloqueo Atrioventricular/epidemiología , Bloqueo Atrioventricular/terapia , Neuropatías Amiloides Familiares/complicaciones , Neuropatías Amiloides Familiares/diagnóstico , Neuropatías Amiloides Familiares/terapia , Pronóstico , Estimulación Cardíaca Artificial/efectos adversos , Factores de Riesgo
3.
Artículo en Inglés | MEDLINE | ID: mdl-37179766

RESUMEN

Multistate methodology proves effective in analyzing hospitalized coronavirus disease 2019 (COVID-19) patients with emerging variants in real time. An analysis of 2,548 admissions in Freiburg, Germany, showed reduced severity over time in terms of shorter hospital stays and higher discharge rates when comparing more recent phases with earlier phases of the pandemic.

6.
Biol Blood Marrow Transplant ; 26(3): 451-457, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31647984

RESUMEN

Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only potentially curative option for myelodysplastic syndromes (MDSs) but is severely limited by nonrelapse mortality (NRM), especially in this mostly older population. Comorbidity assessment is crucial to predict NRM and often assessed with the Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI). Moreover, the impact of age on NRM still remains a matter of debate. In recent years, the age at which transplants are made has been progressively increasing, and patients with comorbidities have become more common. Extricating the respective roles of age and comorbidities in toxic mortality is all the more important. This study by the European Group for Blood and Marrow Transplantation registry included 1245 adult patients who underwent a first allogeneic stem cell transplantation for MDSs between 2003 and 2014. Overall, 4-year NRM and overall survival were 32% and 47%, respectively. When considered as continuous predictors, HCT-CI score and age were associated with an increased hazard ratio (HR) for NRM. In multivariate analysis, age band (HR, 1.13; 95% CI, 1.02 to 1.25; P= .016), HCT-CI ≥3 (HR, 1.34; 95% CI, 1.04 to 1.73; P = .022), and Karnofsky Performance Status ≤80 (HR, 2.03; 95% CI, 1.52 to 2.73; P< .0001) were significantly predictive of a worse NRM. In our large cohort, both comorbidities, evaluated by the original HCT-CI score, and chronological age significantly affected NRM. Thus, age should be part of the transplant decision-making process and should be integrated in future scoring systems predicting outcomes of HSCT in MDSs.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Neoplasias , Adulto , Médula Ósea , Comorbilidad , Humanos , Estudios Retrospectivos , Acondicionamiento Pretrasplante
7.
Anesthesiology ; 129(4): 721-732, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30074928

RESUMEN

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Complications in pediatric regional anesthesia are rare, so a large sample size is necessary to quantify risk. The Pediatric Regional Anesthesia Network contains data on more than 100,000 blocks administered at more than 20 children's hospitals. This study analyzed the risk of major complications associated with regional anesthesia in children. METHODS: This is a prospective, observational study of routine clinical practice. Data were collected on every regional block placed by an anesthesiologist at participating institutions and were uploaded to a secure database. The data were audited at multiple points for accuracy. RESULTS: There were no permanent neurologic deficits reported (95% CI, 0 to 0.4:10,000). The risk of transient neurologic deficit was 2.4:10,000 (95% CI, 1.6 to 3.6:10,000) and was not different between peripheral and neuraxial blocks. The risk of severe local anesthetic systemic toxicity was 0.76:10,000 (95% CI, 0.3 to 1.6:10,000); the majority of cases occurred in infants. There was one epidural abscess reported (0.76:10,000, 95% CI, 0 to 4.8:10,000). The incidence of cutaneous infections was 0.5% (53:10,000, 95% CI, 43 to 64:10,000). There were no hematomas associated with neuraxial catheters (95% CI, 0 to 3.5:10,000), but one epidural hematoma occurred with a paravertebral catheter. No additional risk was observed with placing blocks under general anesthesia. The most common adverse events were benign catheter-related failures (4%). CONCLUSIONS: The data from this study demonstrate a level of safety in pediatric regional anesthesia that is comparable to adult practice and confirms the safety of placing blocks under general anesthesia in children.


Asunto(s)
Anestesia de Conducción/efectos adversos , Anestésicos Locales/efectos adversos , Bloqueo Nervioso/efectos adversos , Complicaciones Posoperatorias/inducido químicamente , Complicaciones Posoperatorias/diagnóstico , Anestesia de Conducción/métodos , Anestésicos Locales/administración & dosificación , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Bloqueo Nervioso/métodos , Estudios Prospectivos
8.
Microb Drug Resist ; 20(1): 17-21, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23987992

RESUMEN

We report the emergence and long-lasting persistence of linezolid resistance in an ampicillin-resistant Enterococcus faecium strain in the intestine of a neutropenic oncohematologic patient receiving chemotherapy. The patient was first colonized by an epidemic ampicillin-resistant E. faecium (ARE)-ST117 clustering into lineage 78. This clone exhibited resistance to levofloxacin, erythromycin and high-level resistance to streptomycin and gentamicin. After receiving treatment with several broad spectrum antibiotics for febrile neutropenia, a 9-day course of oral linezolid was administered once the patient developed bacteraemia by the same ARE colonizing clone. Linezolid-resistant ARE was detected 17 days later in the follow-up fecal samples and persisted 41 days after suppression of linezolid therapy. Resistance to linezolid was associated with G2576T transversion in the 23S rRNA and the presence of cfr gene was not detected. The persistence of G2576T-ARE strains, especially in oncohematologic patients with injured intestinal membranes, could increase the risk of bacteraemia.


Asunto(s)
Acetamidas/uso terapéutico , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/genética , Enterococcus faecium/genética , Leucemia/microbiología , Oxazolidinonas/uso terapéutico , Mutación Puntual , ARN Ribosómico 23S/genética , Enfermedad Aguda , Anciano , Antineoplásicos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Enterococcus faecium/efectos de los fármacos , Enterococcus faecium/patogenicidad , Infecciones por Bacterias Grampositivas/complicaciones , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/patología , Humanos , Leucemia/complicaciones , Leucemia/tratamiento farmacológico , Leucemia/patología , Linezolid , Masculino , Neutropenia/complicaciones , Neutropenia/tratamiento farmacológico , Neutropenia/microbiología , Neutropenia/patología
11.
Immunology ; 134(3): 305-13, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21978000

RESUMEN

Studies in long-term non-progressors (LTNP) have suggested that the quality of the CD8(+) response may involve protective human leucocyte antigen (HLA) class I alleles. However, studies examining the expansion ability of different functional CD8(+) T cells and their association with HLA class I alleles are lacking. LTNP, untreated typical progressors (TP) and patients successfully on highly active retroviral therapy (HAART) during 1 year (HP) were included. HLA class I typing was performed using a sequence-specific primer assay. Functional subsets of Gag- and Nef-specific CD8(+) cells were analysed based on the production of macrophage inflammatory protein (MIP)-1ß, tumour necrosis factor (TNF)-α and interleukin (IL)-2. Their expansion abilities were evaluated after 10-day culture in the presence of Gag and Nef human immunodeficiency virus (HIV) peptides. No differences were seen when comparing quantitative and qualitative HIV-specific CD8(+) T cell responses according to the presence/absence of protective HLA alleles (B*58 and B*27 supertypes) in each group. However, LTNP with protective HLA alleles showed a higher expansion ability of Gag-specific MIP(+) TNF(+) IL-2(+) T cells and Nef-specific MIP(+) TNF(+) IL-2(+) . HLA-B*5701+LTNP displayed a higher expansion ability of Gag and Nef-specific MIP(+) TNF(-) IL-2(+) T cells than HLA-B*5701-LTNP. This was not so for HLA-B*2705. No differences were seen in the expansion ability according to the presence/absence of protective HLA alleles in TP and HP. The expansion ability of polyfunctional CD8(+) T cells is modulated by HLA class I alleles and targeted protein. LTNP with HLA class I protective alleles (mainly B*5701) display better expansion ability of polyfunctional HIV-specific CD8(+) T cells than the rest, suggesting that factors other than HLA-B*5701 must contribute to the control of viral replication in other LTNP. Furthermore, these attributes of HIV-specific CD8(+) T are not restored by HAART; thus, adjuvant therapies and vaccines that induce and/or normalize the expansion ability of HIV-specific T cells are required.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Sobrevivientes de VIH a Largo Plazo , VIH/inmunología , Antígenos HLA-B/inmunología , Adulto , Alelos , Terapia Antirretroviral Altamente Activa , Recuento de Linfocito CD4 , Linfocitos T CD8-positivos/metabolismo , Proliferación Celular , Células Cultivadas , Quimiocina CCL4/inmunología , Quimiocina CCL4/metabolismo , Femenino , Frecuencia de los Genes , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/genética , Infecciones por VIH/inmunología , Antígenos HLA-B/genética , Antígeno HLA-B27/genética , Antígeno HLA-B27/inmunología , Humanos , Interleucina-2/inmunología , Interleucina-2/metabolismo , Masculino , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Replicación Viral/inmunología , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/inmunología
12.
J Acquir Immune Defic Syndr ; 58(5): 436-41, 2011 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-21876448

RESUMEN

BACKGROUND: Cross-sectional studies in HIV-positive patients have suggested that interleukin 7 (IL-7) may increase in parallel to CD4 decline during the natural course of HIV infection. We tested this hypothesis in a longitudinal study examining the evolution of IL-7 and CD4 counts in 2 different scenarios. METHODS: IL-7 and CD4 counts were regularly monitored in 30 drug-naive patients during a follow-up period of 46 ± 14 months in the absence of therapy and in 42 patients who started highly active antiretroviral therapy and maintained undetectable viremia for 2 years. Multivariate linear regression analysis was used to ascertain what factors were associated with IL-7 variations during follow-up. RESULTS: In antiretroviral therapy-naive patients, CD4 counts significantly decreased (P < 0.0001), whereas plasma HIV-RNA and IL-7 levels remained fairly stable. In patients on highly active antiretroviral therapy, CD4 counts significantly increased (P < 0.0001) and IL-7 tended to decrease (P = 0.1). There was no correlation between CD4 and IL-7 variations either in the naive or in the treated population. The only parameter significantly associated with IL-7 variation during follow-up was its baseline level that showed a negative correlation. CONCLUSIONS: In HIV patients with low or moderate degree of immunodeficiency, CD4 counts and plasma IL-7 levels do not evolve in parallel, suggesting that other factors different from CD4 counts must be involved in the upregulation of IL-7 observed in HIV infection.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Interleucina-7/sangre , Adulto , Fármacos Anti-VIH/administración & dosificación , Recuento de Linfocito CD4 , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Masculino , ARN Viral/sangre , Estudios Retrospectivos , Factores de Tiempo , Viremia
13.
J Clin Neurosci ; 18(9): 1180-4, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21757355

RESUMEN

Antiepileptic drugs (AED) are known to cause coagulation disturbances. We retrospectively analyzed the effect of AED on coagulation parameters in children who underwent craniotomy for epilepsy surgery. A total of 84 children were included. Perioperative coagulation parameters, the number and type of AED, estimated blood loss and the amount of blood products transfused were recorded. The most commonly used AED was lamotrigine. Of all patients, 7.1% were taking valproate. None of the patients showed significantly abnormal prothrombin time, activated partial thromboplastin time, or platelet count preoperatively. Thirty-eight percent of patients were transfused with allogeneic red blood cells and 4.7% of all patients showed significant coagulopathy intraoperatively and postoperatively. We concluded that the number of AED does not appear to be associated with preoperative coagulation disorders or blood transfusion requirements. However, caution should be taken in patients taking AED who undergo complex brain epilepsy surgery due to the potential for significant blood loss.


Asunto(s)
Anticonvulsivantes/uso terapéutico , Coagulación Sanguínea/efectos de los fármacos , Craneotomía/efectos adversos , Epilepsia/tratamiento farmacológico , Hemorragia/tratamiento farmacológico , Adolescente , Pruebas de Coagulación Sanguínea , Niño , Epilepsia/cirugía , Femenino , Hemorragia/etiología , Humanos , Masculino , Periodo Perioperatorio/métodos , Recuento de Plaquetas , Estudios Retrospectivos
14.
J Immunol ; 185(2): 982-9, 2010 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-20543099

RESUMEN

HIV-specific T cells response and T cell activation are frequently seen in exposed seronegative individuals (ESN). In this study, we report HIV-specific response and level of T cell activation in ESN partners of HIV-infected patients presenting low or undetectable levels of HIV-RNA. We evaluated 24 HIV-serodiscordant couples. ESN were classified into three categories of exposure to HIV (very low, low, and moderate-high), considering levels of HIV-RNA in their infected partner and frequency of sexual high-risk practices within the last 12 mo. HIV-specific T cell responses and activation levels in T cell subsets were evaluated by flow cytometry. We reported that 54% of ESN had detectable HIV-specific T cells response, being the highest prevalence seen in the low exposure group (64%). Several T cell subsets were significantly increased in ESN when compared with controls: CD4(+)CD38(+) (p = 0.006), CD4(+)HLA-DR(-)CD38(+) (p = 0.02), CD4(+)CD45RA(+)CD27(+)HLA-DR(-)CD38(+) (p = 0.002), CD8(+)CD45RA(+)CD27(+)CD38(-)HLA-DR(+) (p = 0.02), and CD8(+)CD45RA(+)CD27(-)CD38(+)HLA-DR(+) (p = 0.03). Activation of CD8(+) T cells was increased in ESN with detectable HIV T cell responses compared with ESN lacking these responses (p = 0.04). Taken together, these results suggest that persistent but low sexual HIV exposure is able to induce virus-specific T cells response and immune activation in a high proportion of ESN, suggesting that virus exposure may occur even in conditions of maximal viral suppression in the HIV-infected partner.


Asunto(s)
Seronegatividad para VIH/inmunología , VIH/inmunología , Activación de Linfocitos/inmunología , Linfocitos T/inmunología , ADP-Ribosil Ciclasa 1/sangre , Adulto , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Quimiocina CCL4/sangre , Femenino , Citometría de Flujo , Infecciones por VIH/sangre , Infecciones por VIH/inmunología , Antígenos HLA-DR/sangre , Humanos , Interferón gamma/sangre , Masculino , Persona de Mediana Edad , Linfocitos T/citología , Linfocitos T/metabolismo
15.
J Infect Dis ; 198(10): 1466-73, 2008 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-18847371

RESUMEN

BACKGROUND: Factors influencing the depletion of CD4(+) cells and the restoration of CD4(+) cells after antiretroviral therapy are not completely understood. Recently, attention has been paid to interleukin (IL)-7 and its receptor (CD127). We analyzed the influence of T cell activation and of suppression of viremia with antiretroviral therapy on this system, as well as its role in CD4(+) cell restoration after long-term antiretroviral therapy. METHODS: IL-7 levels and CD127 expression on several subsets of CD4(+) and CD8(+) T lymphocytes and the activation status (CD38) of these cells were examined at baseline and during 24 months of complete viral suppression under highly active antiretroviral therapy (HAART). RESULTS: A total of 42 individuals with human immunodeficiency virus (HIV) infection and 10 age-matched, uninfected control subjects were examined. Before HAART, IL-7 levels were increased and CD127 expression was decreased. Down-regulation of CD127 was mainly associated with T cell activation and reverted only partially after suppression of detectable plasma HIV RNA with HAART. In a multivariate analysis, CD127 expression on CD8(+) T cells was the main determinant of the extent of CD4(+) cell gains after successful HAART. CONCLUSIONS: The IL-7-CD127 system is impaired in HIV-infected patients. CD127 down-regulation is associated with T cell activation and with CD4(+) cell restoration after HAART.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa , Linfocitos T CD4-Positivos/inmunología , Regulación hacia Abajo , Infecciones por VIH , Subunidad alfa del Receptor de Interleucina-7/inmunología , Activación de Linfocitos/inmunología , Fármacos Anti-VIH/inmunología , Recuento de Linfocito CD4 , Estudios de Casos y Controles , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , VIH-1/inmunología , Humanos , Interleucina-7/sangre , ARN Viral/sangre , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/virología
16.
AIDS Res Hum Retroviruses ; 24(9): 1185-95, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18729773

RESUMEN

The mechanism explaining the failure of HIV-specific CD8(+) T cell responses to successfully control HIV replication remains elusive. A total of 83 drug-naive HIV-infected individuals, 27 of whom were long-term nonprogressors (LTNP), was examined. The ability of CD8(+) T lymphocytes to produce three different cytokines (MIP-1beta, TNF-alpha, IL-2) in response to HIV Gag and Nef peptides and to polyclonal stimuli and the ability of HIV-specific CD8(+) T cells to expand in vitro were evaluated by multiparameter flow cytometry. In response to polyclonal stimulation, LTNP presented significantly higher levels of several CD8(+) T cell subsets than progressors. While most patients presented detectable Gag and Nef-specific CD8(+) responses, no significant differences in any of the CD8(+) functional T cell subsets were recognized when comparing LTNP and progressors. HIV responses were dominated by cells producing only MIP-1beta or TNF-alpha, being similar in LTNP and progressors. However, expansion of HIV-specific CD8(+) T cells was more frequent in LTNP than progressors, especially for cells producing MIP-1beta. LTNP show higher levels of CD8(+) responses against polyclonal stimuli than progressors. However, HIV-specific CD8(+) responses do not differ between them except for a more preserved ability of cells from LTNP to expand in vitro.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/inmunología , Sobrevivientes de VIH a Largo Plazo , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/inmunología , Proliferación Celular , Quimiocina CCL4/biosíntesis , Citometría de Flujo , Humanos , Interleucina-2/biosíntesis , Factor de Necrosis Tumoral alfa/biosíntesis
17.
J Med Virol ; 79(8): 1040-6, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17596837

RESUMEN

Viral tropism plays an important role in HIV pathogenesis. However, its correlation with the clinical outcome and following exposure to antiretroviral drugs are still unclear. HIV-1 co-receptor usage was examined in 206 infected individuals: 67 seroconverters, 52 chronically drug-naïve, and 87 antiretroviral-experienced patients. The V3 loop was sequenced from plasma HIV-RNA and co-receptor usage was inferred using a phenotype predictor software (http://genomiac2.ucsd.edu:8080/wetcat/v3.html), which classifies V3 sequences as R5 or X4. The overall prevalence of X4 viruses was 26.2%, with significant differences among groups: 13.4% in seroconverters, 25% in drug-naïve, and 36.8% in antiretroviral- experienced patients (P = 0.001). The presence of X4 variants in the latter group was associated with higher viral load (P = 0.002) but not with lower CD4 counts. There was no association between HIV tropism and gender, transmission route or age. Neither with the CCR5 Delta32 genotype. Moreover, no association was found between HIV-1 tropism and drug resistance mutations nor with failure to regimens based on either protease inhibitors or non-nucleoside reverse transcriptase inhibitors. Finally, no significant association was found between IL-7 plasma levels with HIV-1 tropism. In summary, X4 viruses are particularly frequent among antiretroviral-experienced patients with high viral loads, irrespective of the CD4 count. Thus, CCR5 antagonists should be used with special caution in this subset of patients.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH-1/genética , Adulto , Farmacorresistencia Viral Múltiple/genética , Femenino , Variación Genética , Humanos , Interleucina-7/sangre , Masculino , ARN Viral/sangre , Receptores de Superficie Celular , Estudios Retrospectivos
18.
AIDS Res Hum Retroviruses ; 22(9): 884-92, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16989614

RESUMEN

The role of cytotoxic T lymphocyte responses in controlling viral replication during chronic HIV infection remains controversial. Viral escape mutations driven by immune pressure have been postulated to be an important mechanism contributing to the evasion of CD8(+) T cell responses. To explore this issue in more detail, HIV-1 p17 sequence variability was examined in chronically HIV-infected patients, in parallel with the level, phenotype, and function of HIV-SL9-specific CD8(+) T cell. Thirty-one HLA-A*0201(+) (A2(+)) and 10 HLAA* 02() (A2()) patients were included. The phenotype of SL9-specific CD8(+) T cell and their ability to produce IFN-gamma were analyzed by multiparameter flow cytometry. The HIV Gag p17 was sequenced and the mean variability score for each residue within SL9 and the two epitope flanking regions were calculated using Shannon entropy. The mean variability of SL9 and the proportion of patients with amino acid changes within SL9 were similar in A2(+) and A2() patients. Patients without Tet(+) cells had a significantly higher prevalence of aminoacid changes in SL9 than patients with Tet(+) cells. Interestingly, in patients with Tet(+) cells, the Y79F mutation within SL9 tended to be associated with lower levels of Tet(+) cells. We did not find any association between amino acid changes within SL9 and the differentiation stage of Tet(+) cells, or with IFN-gamma production. A similar analysis within the epitope flanking sequences did not reveal differences in the variability of these regions. These results suggest that viral mutations driven by immune selection pressure may play an important role in evading the immunological response in chronically HIV-infected individuals.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T/inmunología , Productos del Gen gag/inmunología , Genes gag/genética , Infecciones por VIH/inmunología , VIH-1/genética , Fragmentos de Péptidos/inmunología , Linfocitos T CD8-positivos/virología , Distribución de Chi-Cuadrado , Productos del Gen gag/genética , Infecciones por VIH/genética , VIH-1/inmunología , Antígenos HLA-A/inmunología , Humanos , Datos de Secuencia Molecular , Mutación , Fragmentos de Péptidos/genética , Fenotipo , Receptores de Antígenos de Linfocitos T/inmunología , Selección Genética , Especificidad del Receptor de Antígeno de Linfocitos T/genética , Especificidad del Receptor de Antígeno de Linfocitos T/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana
19.
AIDS Res Hum Retroviruses ; 22(8): 734-43, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16910828

RESUMEN

Both hydroxyurea (HU) and structured treatment interruptions (STI) have been investigated as therapeutic approaches to enhance immune responses in chronically HIV-infected individuals. HIV-specific T cell responses as well as T cell activation were analyzed longitudinally in 31 HIV-infected individuals who had been treated for the prior 12 months with didanosine (ddI) plus HU and thereafter completed three STI cycles consisting of 2 months off and 2 months on ddI-HU. Similar increases in plasma HIV-RNA were seen in each of the three cycles off therapy, whereas CD4 counts remained fairly stable along the study period. T cell activation paralleled the evolution of plasma HIV-RNA during the first STI cycle and waned afterward. At baseline most patients presented a high level of CD8+ responses to different HIV peptide pools and 23% of them had CD4+ responses to Gag and/or Env. The level of CD8+ responses against each pool was stable and did not increase during STI cycles, while CD4 responses tended to decline. However, the contribution of Nef-specific response to the total CD8 response tended to increase. In a multivariate model, both a higher baseline plasma HIV-RNA and a higher level of Nef-specific response contribution to the total CD8+ response were independently associated with lower plasma HIV-RNA increases during each of the three STI cycles. Nef-specific CD8+ responses might contribute to a better virological control of HIV replication following treatment interruptions in HIV-infected individuals and might be boosted by the immunomodulatory effect of HU.


Asunto(s)
Fármacos Anti-VIH/administración & dosificación , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD8-positivos/efectos de los fármacos , Didanosina/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Hidroxiurea/administración & dosificación , ADP-Ribosil Ciclasa 1/metabolismo , Adulto , Fármacos Anti-VIH/inmunología , Terapia Antirretroviral Altamente Activa/métodos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Distribución de Chi-Cuadrado , Didanosina/inmunología , Quimioterapia Combinada , Femenino , Productos del Gen nef/sangre , Infecciones por VIH/inmunología , Humanos , Hidroxiurea/inmunología , Inmunidad Celular , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/inmunología , Masculino , Persona de Mediana Edad , ARN Viral/sangre , Análisis de Regresión , Productos del Gen nef del Virus de la Inmunodeficiencia Humana
20.
J Infect Dis ; 192(12): 2142-6, 2005 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-16288380

RESUMEN

CD38 expression on CD8(+) T cells was longitudinally assessed in 31 human immunodeficiency virus (HIV)-infected persons with undetectable plasma viremia who had undergone highly active antiretroviral therapy (HAART) for 12 months and were followed for a mean of 30 months thereafter. Overall, CD4(+)T cell counts increased during follow-up, whereas CD38 expression remained stable. However, a subset of patients showed declines in CD38 expression, and, conversely, another subset showed increases in CD38 expression. No association could be found between long-term gains in CD4(+) T cells and evolution of CD38 expression. Thus, activation of CD8(+) T cells does not seem to be associated with the extent of CD4(+) T cell recovery beyond the first year of successful HAART.


Asunto(s)
Terapia Antirretroviral Altamente Activa , Recuento de Linfocito CD4 , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/inmunología , Activación de Linfocitos , Subgrupos de Linfocitos T/inmunología , ADP-Ribosil Ciclasa 1/análisis , VIH/efectos de los fármacos , VIH/fisiología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Humanos , Carga Viral , Viremia , Replicación Viral/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...