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1.
J Exp Med ; 185(1): 55-64, 1997 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-8996241

RESUMO

Apoptosis of bystander uninfected CD4+ T lymphocytes by neighboring HIV-infected cells is observed in cell culture and in lymphoid tissue of HIV-infected individuals. This study addresses whether antigen-presenting cells such as human macrophages mediate apoptosis of CD4+ T cells from HIV-infected individuals. Uninfected human macrophages, and to a larger degree, HIV-infected macrophages mediate apoptosis of T cells from HIV-infected, but not from uninfected control individuals. This macrophage-dependent killing targets CD4+, but not CD8+ T lymphocytes from HIV-infected individuals, and direct contact between macrophages and lymphocytes is required. Additional analyses indicated that the apoptosis-inducing ligands, FasL and tumor necrosis factor (TNF), mediate this macrophage-induced apoptosis of CD4+ T cells. These results support a role for macrophage-associated FasL and TNF in the selective depletion of CD4+ T cells in HIV-infected individuals.


Assuntos
Apoptose , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , Macrófagos/imunologia , Glicoproteínas de Membrana/fisiologia , Fator de Necrose Tumoral alfa/fisiologia , Anticorpos Monoclonais , Antígenos de Superfície/fisiologia , Linfócitos T CD4-Positivos/fisiologia , Células Cultivadas , Técnicas de Cocultura , Proteína Ligante Fas , Citometria de Fluxo , Soronegatividade para HIV , Soropositividade para HIV/imunologia , Humanos , Tecido Linfoide/imunologia , Proteínas Recombinantes de Fusão/imunologia
2.
Clin Pharmacol Ther ; 82(3): 294-9, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17361127

RESUMO

Human immunodeficiency virus (HIV) infection results in excessive apoptosis of infected and uninfected cells, mediated by host and viral factors present in plasma. As HIV protease inhibitors (PIs) have intrinsic antiapoptotic properties, we questioned whether HIV PIs could block HIV-induced CD4+ T-cell death independent of their effects on HIV replication. We demonstrate that HIV PIs block the death of CD4+ T cells induced by HIV glycoprotein 120 (gp120), Vpr, and Tat, as well as host signals Fas ligand, tumor necrosis factor, and tumor necrosis factor-related apoptosis-inducing ligand. Using gp120/CXCR4 as a model, we show that the HIV PIs specifically block mitochondrial apoptosis signaling. Furthermore, HIV PIs inhibit CD4+ T-cell death induced by viruses with high-level resistance to PIs (P<0.01) and apoptosis induced by serum of HIV patients with known resistance to HIV PIs (P=0.01). Together, these results show that HIV PIs block CD4+ T-cell death and have a beneficial effect on CD4+ T-cell survival despite PI resistance.


Assuntos
Linfócitos T CD4-Positivos/efeitos dos fármacos , Inibidores da Protease de HIV/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quimiotaxia de Leucócito/efeitos dos fármacos , Farmacorresistência Viral , Proteína Ligante Fas/antagonistas & inibidores , Proteína Ligante Fas/toxicidade , Citometria de Fluxo , Produtos do Gene tat/antagonistas & inibidores , Produtos do Gene tat/toxicidade , Produtos do Gene vpr/antagonistas & inibidores , Produtos do Gene vpr/toxicidade , Proteína gp120 do Envelope de HIV/toxicidade , HIV-1/efeitos dos fármacos , Humanos , Nelfinavir/farmacologia , Receptores CXCR4/antagonistas & inibidores , Ligante Indutor de Apoptose Relacionado a TNF/antagonistas & inibidores , Ligante Indutor de Apoptose Relacionado a TNF/toxicidade , Replicação Viral/efeitos dos fármacos , Produtos do Gene tat do Vírus da Imunodeficiência Humana , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
3.
J Clin Invest ; 102(1): 79-87, 1998 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-9649560

RESUMO

Recent insights into the pharmacological control of HIV replication and the molecular mechanisms of peripheral T cells homeostasis allowed us to investigate in vivo the mechanisms mediating T cell depletion in HIV-infected patients. Before the initiation of highly active antiretroviral therapy (HAART), a high degree of lymphoid tissue apoptosis is present, which is reduced upon HAART initiation (P < 0.001) and directly correlates with reduction of viral load and increases of peripheral T lymphocytes (P < 0.01). Because Fas/FasL interactions play a key role in peripheral T lymphocyte homeostasis, we investigated the susceptibility to Fas-mediated apoptosis in peripheral T lymphocytes and of FasL expression in lymphoid tissue before and during HAART. High levels of Fas-susceptibility found in peripheral CD4 T lymphocytes before HAART were significantly reduced after HAART, coinciding with decreases in viral load (P = 0.018) and increases in peripheral CD4 T lymphocyte counts (P < 0.01). However, the increased FasL expression in the lymphoid tissue of HIV-infected individuals was not reduced after HAART. These results demonstrate that lymphoid tissue apoptosis directly correlates with viral load and peripheral T lymphocyte numbers, and suggest that HIV-induced susceptibility to Fas-dependent apoptosis may play a key role in the regulation of T cell homeostasis in HIV-infected individuals.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/imunologia , Glicoproteínas de Membrana/metabolismo , Receptor fas/metabolismo , Apoptose/efeitos dos fármacos , Contagem de Linfócito CD4 , Proteína Ligante Fas , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Humanos , Ativação Linfocitária , Linfócitos T/efeitos dos fármacos , Linfócitos T/fisiologia
4.
J Clin Invest ; 101(11): 2394-405, 1998 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-9616211

RESUMO

Fas/Fas Ligand (FasL) interactions play a significant role in peripheral T lymphocyte homeostasis and in certain pathological states characterized by T cell depletion. In this study, we demonstrate that antigen-presenting cells such as monocyte-derived human macrophages (MDM) but not monocyte-derived dendritic cells express basal levels of FasL. HIV infection of MDM increases FasL protein expression independent of posttranslational mechanisms, thus highlighting the virus-induced transcriptional upregulation of FasL. The in vitro relevance of these observations is confirmed in human lymphoid tissue. FasL protein expression is constitutive and restricted to tissue macrophages and not dendritic cells. Moreover, a significant increase in macrophage-associated FasL is observed in lymphoid tissue from HIV (+) individuals (P < 0.001), which is further supported by increased levels of FasL mRNA using in situ hybridization. The degree of FasL protein expression in vivo correlates with the degree of tissue apoptosis (r = 0.761, P < 0. 001), which is significantly increased in tissue from HIV-infected patients (P < 0.001). These results identify human tissue macrophages as a relevant source for FasL expression in vitro and in vivo and highlight the potential role of FasL expression in the immunopathogenesis of HIV infection.


Assuntos
HIV/fisiologia , Macrófagos/metabolismo , Glicoproteínas de Membrana/biossíntese , Apoptose , Células Cultivadas , Células Dendríticas/metabolismo , Proteína Ligante Fas , Regulação da Expressão Gênica , Humanos , Glicoproteínas de Membrana/genética , Regulação para Cima
5.
Cell Death Differ ; 12 Suppl 1: 924-31, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15761470

RESUMO

Development of potent inhibitors of HIV protease has revolutionized the treatment of HIV infection. HIV protease inhibitors (PI) have caused more dramatic improvements in CD4 T-cell numbers than in other therapies that were available previously, prompting investigators to assess whether PI possess intrinsic immunomodulatory effects. An emerging body of data indicates that HIV PIs are antiapoptotic, although the exact molecular target responsible for this antiapoptotic effect remains to be defined in vitro and in vivo. Paradoxically, high-dose PI also may have proapoptotic effects, particularly when assessed in vitro in transformed cell lines and implanted mouse models. Future research will define molecular targets of PI that are responsible for their apoptotis modulatory effects (both pro- and anti-apoptotic). In addition, evaluation of the clinical utility of PI-based therapy in those non-HIV disease states that are characterized by excessive apoptotis will reveal the full clinical potential of this intriguing class of drugs.


Assuntos
Apoptose/efeitos dos fármacos , Relação CD4-CD8 , Protease de HIV/metabolismo , Inibidores de Proteases/farmacologia , Inibidores de Proteases/uso terapêutico , Animais , Terapia Antirretroviral de Alta Atividade , Calpaína/antagonistas & inibidores , Calpaína/metabolismo , Inibidores de Caspase , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Inibidores de Proteases/toxicidade
6.
Cell Death Differ ; 6(5): 420-32, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10381636

RESUMO

T cells from HIV infected patients undergo spontaneous apoptosis at a faster rate than those from uninfected patients, are abnormally susceptible to activation induced cell death (AICD), and undergo increased apoptosis in response to Fas receptor ligation. These observations have led to the hypothesis CD4 T cell apoptosis may be a mechanism of CD4 T cell depletion and the pathogenesis of AIDS. Successful treatment of HIV infected patients is accompanied by quantitative and qualitative improvements in immune function reflecting at least partial reversibility of the underlying pathogenesis of HIV. In this report we correlate improvements in markers of immune function with a decrease in apoptosis, and changes in its regulation. Therapy with nelfinavir plus saquinavir in combination with two nucleoside analogue inhibitors of reverse transcriptase dramatically reduces plasma viremia and increases CD4 T cell counts. Coincident with these improvements, CD38 and HLA-DR coexpression on both CD4 and CD8 T cells decrease, and CD45RA and CD62L coexpression increase. Furthermore, spontaneous apoptosis decreases in both CD4 and CD8 T cells (CD4 apoptosis 17.4 vs 2.6%, P=0.005; CD8 apoptosis 15.0 vs 1.0%, P<0.001), as does both Fas mediated apoptosis (CD4 apoptosis 19.0 vs 3.5%, P=0.03; CD8 apoptosis 13.7 vs 1.5%, P=0.002) and CD3 induced AICD (CD4 apoptosis 13.7 vs 3.2%, P=0.001; CD8 apoptosis 29 vs 2.2%, P=0.08). Changes in apoptosis are not associated with changes in Fas receptor expression, but are significantly correlated with changes in activation marker profiles. Although this suggests a possible regulatory role for the apoptosis inhibitory protein FLIP, direct assessment did not reveal quantitative differences in FLIP expression between apoptosis resistant PBL's from HIV negative patients, and apoptosis sensitive PBL's from HIV positive patients. These findings support the hypothesis that apoptosis mediates HIV induced CD4 T cell depletion, but indicate the need for further studies into the molecular regulation of HIV induced apoptosis.


Assuntos
Apoptose , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Peptídeos e Proteínas de Sinalização Intracelular , Adolescente , Adulto , Fármacos Anti-HIV/uso terapêutico , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD , Proteínas de Transporte/biossíntese , Quimioterapia Combinada , Infecções por HIV/virologia , Inibidores da Protease de HIV/uso terapêutico , Humanos , Pessoa de Meia-Idade , Nelfinavir/uso terapêutico , Nucleosídeos/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Saquinavir/uso terapêutico , Linfócitos T/imunologia , Receptor fas/biossíntese
7.
Cell Death Differ ; 9(11): 1172-84, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12404116

RESUMO

Infection of T cells with HIV-1 induces apoptosis and modulates apoptosis regulatory molecules. Similar effects occur following treatment of cells with individual HIV-1 encoded proteins. While HIV-1 protease is known to be cytotoxic, little is known of its effect on apoptosis and apoptosis regulatory molecules. The ability of HIV-1 protease to kill cells, coupled with the degenerate substrate specificity of HIV-1 protease, suggests that HIV-1 protease may activate cellular factor(s) which, in turn, induce apoptosis. We demonstrate that HIV-1 protease directly cleaves and activates procaspase 8 in T cells which is associated with cleavage of BID, mitochondrial release of cytochrome c, activation of the downstream caspases 9 and 3, cleavage of DFF and PARP and, eventually, to nuclear condensation and DNA fragmentation that are characteristic of apoptosis. The effect of HIV-1 protease is not seen in T cell extracts which have undetectable levels of procaspase 8, indicating a specificity and requirement for procaspase 8.


Assuntos
Caspases/metabolismo , Grupo dos Citocromos c/metabolismo , Precursores Enzimáticos/metabolismo , Protease de HIV/metabolismo , HIV-1/enzimologia , Apoptose/fisiologia , Caspase 3 , Caspase 8 , Caspase 9 , Fragmentação do DNA/fisiologia , Células HeLa , Humanos , Células Jurkat , Mitocôndrias/metabolismo
8.
AIDS ; 15(14): 1749-56, 2001 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-11579235

RESUMO

OBJECTIVE: To characterize immune phenotype and thymic function in HIV-1-infected adults with excellent virologic and poor immunologic responses to highly active antiretroviral therapy (HAART). METHODS: Cross-sectional study of patients with CD4 T cell rises of > or = 200 x 10(6) cells/l (CD4 responders; n = 10) or < 100 x 10(6) cells/l (poor responders; n = 12) in the first year of therapy. RESULTS: Poor responders were older than CD4 responders (46 versus 38 years; P < 0.01) and, before HAART, had higher CD4 cell counts (170 versus 35 x 106 cells/l; P = 0.11) and CD8 cell counts (780 versus 536 x 10(6) cells/l; P = 0.02). After a median of 160 weeks of therapy, CD4 responders had more circulating naive phenotype (CD45+CD62L+) CD4 cells (227 versus 44 x 10(6) cells/l; P = 0.001) and naive phenotype CD8 cells (487 versus 174 x 10(6) cells/l; P = 0.004) than did poor responders (after 130 weeks). Computed tomographic scans showed minimal thymic tissue in 11/12 poor responders and abundant tissue in 7/10 responders (P = 0.006). Poor responders had fewer CD4 cells containing T cell receptor excision circles (TREC) compared with CD4 responders (2.12 versus 27.5 x 10(6) cells/l; P = 0.004) and had shorter telomeres in CD4 cells (3.8 versus 5.3 kb; P = 0.05). Metabolic labeling studies with deuterated glucose indicated that the lower frequency of TREC-containing lymphocytes in poor responders was not caused by accelerated proliferation kinetics. CONCLUSION: Poor CD4 T cell increases observed in some patients with good virologic response to HAART may be caused by failure of thymic T cell production.


Assuntos
Terapia Antirretroviral de Alta Atividade , Linfócitos T CD4-Positivos/fisiologia , Infecções por HIV/tratamento farmacológico , HIV-1/imunologia , Timo/fisiologia , Adulto , Linfócitos T CD4-Positivos/imunologia , Feminino , Rearranjo Gênico do Linfócito T/genética , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/fisiologia , Humanos , Subpopulações de Linfócitos , Masculino , Pessoa de Meia-Idade , Telômero/genética , Replicação Viral
9.
Front Biosci ; 9: 338-41, 2004 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-14766370

RESUMO

It has been proposed that antiretroviral therapies (ART) possess both antiviral and immunomodulatory activities when used in HIV infected patients. Few studies have addressed whether these putative immunomodulatory effects are also seen in HIV negative patients, for example, when used for post exposure prophylaxis (PEP). We chose to evaluate immunologic function in HIV negative patients who received Nelfinavir and Combivir (AZT and 3TC) as PEP. Lymphocytes from patients taken immediately before, during, and after PEP were analyzed. No changes were seen in absolute or percent CD4 or CD8 T lymphocyte numbers, nor in markers of activation, memory, or co-stimulatory molecules. Surface expression of apoptosis-related ligands and receptors were unaltered, but apoptosis susceptibility was significantly inhibited by PEP (P less than 0.05). These data confirm in vitro that apoptosis susceptibility is altered by ART, including in HIV-negative patients who take PEP.


Assuntos
Fármacos Anti-HIV/efeitos adversos , Terapia Antirretroviral de Alta Atividade/efeitos adversos , Apoptose , Infecções por HIV/patologia , Adulto , Animais , Fármacos Anti-HIV/uso terapêutico , Combinação de Medicamentos , Infecções por HIV/tratamento farmacológico , Humanos , Lamivudina/efeitos adversos , Lamivudina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Nelfinavir/efeitos adversos , Nelfinavir/uso terapêutico , Zidovudina/efeitos adversos , Zidovudina/uso terapêutico
10.
Transplantation ; 66(8): 1020-8, 1998 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-9808486

RESUMO

BACKGROUND: Cytomegalovirus (CMV) infection and disease has been found to be associated with decreased graft and patient survival among heart transplant recipients. We sought to explore the effect of CMV infection and disease on long-term survival in orthotopic liver transplant (OLT) recipients using a derivation and validation cohort. METHODS: For derivation-validation modeling, we used data collected from two prospectively followed cohorts as the basis for multivariate analyses: 167 OLT recipients from the Boston Center for Liver Transplantation (the derivation set; median follow-up: 5.5 years, mortality: 40%) and an independent cohort of 294 OLT recipients from the Mayo Clinic (the validation set; median follow-up: 4.8 years, mortality: 27%). RESULTS: Underlying liver disease other than primary biliary cirrhosis or sclerosing cholangitis, number of units of red blood cells administered during transplantation, and donor CMV seropositivity were the pre- and intratransplant variables independently associated (P<0.01) with decreased long-term survival in the derivation cohort. For variables collected up to 1 year after transplantation, the need for retransplan. tation, CMV pneumonia, invasive fungal disease, and underlying liver disease other than primary biliary cirrhosis or sclerosing cholangitis were independently associated (P<0.01) with decreased long-term survival in the derivation cohort. The magnitude of the relationship of each pre-, intra-, and posttransplant factor with survival, as measured by the relative risk, did not significantly differ between the derivation and validation cohorts. The derivation model, incorporating pre-, intra-, and posttransplant factors, had receiver operating characteristic areas of 73% and 74% for 5-year mortality in the derivation and validation cohorts, respectively. CONCLUSIONS: Data from a derivation and an independent validation cohort demonstrate that CMV factors (reflected by either donor CMV seropositivity at transplantation, CMV pneumonia, or CMV disease within the first posttransplant year) are independently associated with decreased long-term survival in OLT recipients.


Assuntos
Infecções por Citomegalovirus/fisiopatologia , Transplante de Fígado , Complicações Pós-Operatórias/fisiopatologia , Adolescente , Adulto , Estudos de Coortes , Feminino , Previsões , Humanos , Masculino , Análise Multivariada , Estudos Prospectivos , Análise de Sobrevida , Fatores de Tempo
11.
Transplantation ; 62(7): 926-34, 1996 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-8878386

RESUMO

Fungal infections are associated with a high mortality rate after liver transplantation. To describe risk factors for fungal infections, 405 consecutive liver transplant recipients were analyzed. Forty-five patients (11%) developed invasive fungal infection. Median posttransplantation time to the first episode was 60 days. Pathogens were Candida species (spp) (n=24, 53%), Cryptococcus neoformans (n=10, 22%), Aspergillus spp (n=6, 13%), Rhizopus spp (n=l), and others (n=4). Presentations of infection included disseminated (n=9), intra-abdominal (n=9), esophageal (n=9), lung (n=8), blood (n=6), and central nervous system infections (n=3), and sinusitis with esophagitis (n=1). Eighteen patients (40%) with invasive fungal infection died, and 13 (72%) of these deaths were attributable to fungi. Mortality in the nonfungal infection group was 12%. Univariate analysis identified separate risk factors for Candida (intra-abdominal bleeding), Aspergillus (fulminant hepatitis), and cryptococcal (symptomatic cytomegalovirus infection) infections. In both univariate and multivariate analyses, a high intratransplant transfusion requirement and posttransplant bacterial infection were identified as significant risk factors for all types of fungal infection. The risk factor analysis reported here suggests that different pathogenic processes lead to Candida and non-Candida infection in liver transplant recipients. Their identification should prompt specific prophylactic measures to reduce morbidity and mortality in this population.


Assuntos
Candidíase/etiologia , Transplante de Fígado , Micoses/etiologia , Complicações Pós-Operatórias , Análise de Variância , Estudos de Avaliação como Assunto , Humanos , Fatores de Risco
12.
Transplantation ; 69(3): 357-61, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10706042

RESUMO

BACKGROUND: We studied the economic impact of cytomegalovirus (CMV) disease and its effective reduction with antiviral prophylaxis in liver transplant recipients. METHOD: Analysis of institutional charge data accumulated during a prospective, randomized, controlled trial comparing oral acyclovir 800 mg four times daily for 120 days (ACV) and intravenous ganciclovir 5 mg/kg every 12 h for 14 days followed by ACV for 106 days (GCV) was performed. RESULTS: Liver transplant recipients who developed CMV disease had significantly higher charges (median: $148,300) than those who developed asymptomatic CMV infection ($119,600) or experienced no CMV infection ($114,100) (P<0.01). A multiple linear regression analysis indicated that CMV disease is associated with a 49% increase in charges, independent of other factors influencing increased hospitalization charges. In CMV-seronegative patients who received a CMV-seropositive donor organ, GCV prophylaxis was associated with a significant reduction in charges, as compared to ACV prophylaxis ($113,900 vs. $153,300, respectively; P=0.02). CONCLUSIONS: CMV disease is an independent risk factor for increased resource utilization associated with liver transplantation. The use of an effective prophylactic antiviral regimen provides savings in health care resources, particularly in patients at high risk for developing CMV disease.


Assuntos
Antivirais/administração & dosagem , Antivirais/economia , Infecções por Citomegalovirus/economia , Infecções por Citomegalovirus/prevenção & controle , Citomegalovirus/isolamento & purificação , Ganciclovir/administração & dosagem , Ganciclovir/economia , Transplante de Fígado/efeitos adversos , Administração Oral , Adulto , Custos e Análise de Custo , Infecções por Citomegalovirus/etiologia , Humanos , Injeções Intravenosas , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Regressão
13.
Transplantation ; 61(8): 1192-7, 1996 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-8610417

RESUMO

To analyze the clinical characteristics of and identify specific risk factors for enterococcal bacteremia following liver transplantation, we performed a study in 405 consecutive liver transplantation recipients prophylaxed with a selective bowel decontamination regimen. Seventy enterococcal bacteremias in 52 patients were identified. Enterococcus faecalis (50) outnumbered Enterococcus faecium isolates (18), and 49% of enterococcal bacteremias were polymicrobial. Biliary tree complications were present in 34% of enterococcal bacteremias. Of the 15 deaths (29%) among the patients with enterococcal bacteremia, 4 were directly associated with enterococcal bacteremia. In a multivariate analysis, Roux-en-Y choledochojejunostomy (P=0.005), a cytomegalovirus-seropositive donor (P=0.013), prolonged transplantation time (P=0.02), and biliary stricturing (P=0.016) were identified as significant risk factors. Other risk factors identified in a univariate analysis included primary sclerosing cholangitis (P=0.009) and symptomatic cytomegalovirus infection (P=0.008). Enterococcal bacteremia is a frequent infectious complication in liver transplantation recipients receiving selective bowel decontamination. Its association with cytomegalovirus and biliary tree abnormalities suggest specific areas for prophylactic intervention.


Assuntos
Enterococcus faecalis/isolamento & purificação , Infecções por Bactérias Gram-Positivas/etiologia , Transplante de Fígado/efeitos adversos , Anastomose em-Y de Roux , Bacteriemia/etiologia , Humanos , Fatores de Risco
14.
Transplantation ; 64(1): 66-73, 1997 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9233703

RESUMO

BACKGROUND: The optimal prophylactic regimen to prevent cytomegalovirus (CMV) infection and disease in orthotopic liver-transplant patients remains to be established. We tested whether a combination of intravenous ganciclovir (GCV) followed by high dosages of oral acyclovir (ACV) for 4 months provided a higher degree of protection from CMV than oral ACV alone. METHODS: One hundred sixty-seven liver-transplant recipients were randomized to receive 120 days of antiviral treatment starting at the time of transplantation consisting of either ACV 800 mg orally four times daily (n=84) or 14 days of GCV 5 mg/kg intravenously every 12 hr followed by oral ACV 800 mg four times daily (n=83). Prospective laboratory and clinical surveillance was performed to determine primary endpoints (onset of CMV infection and CMV disease) and secondary endpoints (rates of fungal and bacterial infection, allograft rejection, and survival after transplantation). One-year event rates are presented as cumulative percentages. RESULTS: During the first year after transplantation, CMV infection developed in 57% of patients treated with ACV and in 37% of patients treated with GCV + ACV (P=0.001). CMV disease developed in 23% of patients treated with ACV and in 11% of patients treated with GCV + ACV (P=0.03). In seronegative recipients of allografts from CMV-seropositive donors (D+/R-), CMV disease developed in 58% of patients treated with ACV and in 25% of patients treated with GCV + ACV (P=0.04). In the D+/R- group, 54% of patients treated with ACV and 17% of patients treated with GCV + ACV developed infection with Candida albicans (P=0.05). CONCLUSIONS: Prophylaxis of CMV infection in liver-transplant patients with 14 days of intravenous GCV followed by high-dosage oral ACV is more effective than high-dosage oral ACV alone at reducing CMV infection and disease, even for patients in the D+/R- CMV serological group.


Assuntos
Aciclovir/uso terapêutico , Antivirais/uso terapêutico , Infecções por Citomegalovirus/prevenção & controle , Ganciclovir/uso terapêutico , Transplante de Fígado , Aciclovir/administração & dosagem , Adulto , Infecções por Citomegalovirus/epidemiologia , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Rejeição de Enxerto/prevenção & controle , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infecções Oportunistas/prevenção & controle , Taxa de Sobrevida
15.
AIDS Res Hum Retroviruses ; 15(17): 1509-18, 1999 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-10580401

RESUMO

The relevance of activation-induced cell death (AICD) of CD4+ T cells to AIDS pathogenesis is unknown. The present study investigates the relationship of AICD to a defined molecular mechanism regulating peripheral T cell homeostasis, Fas-mediated apoptosis, and clinical correlates of the pathogenesis of AIDS. Increased pokeweed mitogen (PWM)-induced AICD (22.8 versus 4.4%, p = 0.006) and Fas-mediated apoptosis (27.7 versus 12.0%, p = 0.002) of CD4+ T cells were observed in HIV+ versus HIV- individuals. Similarly, increased PWM-mediated AICD (16.2 versus 2.2%, p < 0.001) and Fas-mediated apoptosis (25.8 versus 7.6%, p = 0.005) were noted in CD8+ T cells from HIV+ versus HIV- individuals. PWM-induced AICD of CD4+ T cells was blocked (83% median specific inhibition) by Fas-blocking antibodies, whereas PWM-induced AICD of CD8+ T cells was Fas independent. Comparison between PWM- and anti-CD3-mediated AICD of CD4+ T cells indicated that PWM- and not CD3-induced AICD is Fas dependent. HIV+ individuals with an HIV RNA copy number of <30,000 copies/ml had lower PWM-induced AICD of CD4+ T cells than did those with an HIV RNA copy number of >30,000 copies/ml (5.7 versus 22.1%, p = 0.034), and PWM-induced AICD inversely correlated with CD4+ T cell count (R = -0.567, p = 0.043). Initiation of HAART decreased PWM-induced CD4+ T cell AICD from 24.4 to 9.4% posttreatment (p = 0.035). These results demonstrate that PWM-induced AICD of CD4+ T cells from HIV+ individuals is mediated by Fas/FasL, parallels the in vivo susceptibility of the CD4+ T cell to Fas-mediated apoptosis, and correlates with clinical markers of AIDS pathogenesis and response to HAART.


Assuntos
Apoptose , Linfócitos T CD4-Positivos/fisiologia , Soropositividade para HIV/imunologia , Soropositividade para HIV/virologia , HIV , Ativação Linfocitária , Receptor fas/fisiologia , Fármacos Anti-HIV/uso terapêutico , Biomarcadores/análise , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/fisiologia , Estudos de Coortes , HIV/imunologia , HIV/isolamento & purificação , Soronegatividade para HIV , Soropositividade para HIV/tratamento farmacológico , Humanos , Imunidade Celular , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Mitógenos de Phytolacca americana/farmacologia , Reação em Cadeia da Polimerase , RNA Viral/análise , Carga Viral
16.
AIDS Res Hum Retroviruses ; 16(6): 559-67, 2000 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-10777146

RESUMO

Antiretroviral treatment of patients infected with HIV results in improvements in CD4+ T cell number. Emerging evidence suggests that some of the improvements in CD4+ T cell number that occur in response to protease inhibitor (PI) therapy may not be accounted for solely by enhanced viral suppression, implying that PI may directly affect T cell survival. Since HIV T cell depletion is associated with enhanced apoptosis, we analyzed the effect of PIs on T cell apoptosis. In vitro treatment of peripheral blood lymphocytes (PBLs) from HIV-infected but untreated patients with reverse transcriptase inhibitors (RTIs) does not alter apoptosis, whereas PI treatment rapidly reduces CD4+ and CD8+ T cell apoptosis. In contrast, PI treatment does not alter apoptosis in PBL blasts from HIV-negative patients, or in Jurkat T cells. Consistent with this observation, 8 days of PI therapy in HIV-infected patients does not significantly alter plasma viremia, yet results in significant inhibition of CD4+ and CD8+ T cell apoptosis. The inhibitory effects of PI on apoptosis have implications concerning the treatment of HIV and its pathogenesis.


Assuntos
Apoptose/efeitos dos fármacos , Infecções por HIV/imunologia , Inibidores da Protease de HIV/farmacologia , HIV-1 , Linfócitos T/efeitos dos fármacos , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/patologia , Células Cultivadas , Didanosina/farmacologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Inibidores da Protease de HIV/uso terapêutico , Soropositividade para HIV , Humanos , Células Jurkat , Nelfinavir/uso terapêutico , Inibidores da Transcriptase Reversa/farmacologia , Inibidores da Transcriptase Reversa/uso terapêutico , Ritonavir/farmacologia , Saquinavir/farmacologia , Saquinavir/uso terapêutico , Linfócitos T/patologia , Linfócitos T/virologia , Carga Viral , Zidovudina/farmacologia
17.
Mayo Clin Proc ; 71(9): 838-46, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8790258

RESUMO

OBJECTIVE: To analyze the rate of infection of de novo, guidewire exchanged, and new site replacement catheters in a cohort of patients in whom catheters were changed on the basis of the clinical discretion of the attending physicians. DESIGN: We conducted an observational cohort study in catheterized patients in the intensive-care unit (ICU). MATERIAL AND METHODS: ICU patients admitted between Jan. 1, 1991, and Dec.31, 1992, were eligible for enrollment in the study. Catheter care, replacement, and duration were prospectively documented. Catheter-related infection was prospectively evaluated. Rates of catheter-related infection were determined for de novo, guidewire exchanged, and new site replacement catheters and analyzed relative to the duration of placement of individual catheters and the total duration of central venous catheterization for a specific patient. RESULTS: Fifty catheter-related infections developed in 2,470 patients. When the rate of catheter-associated infection was determined for each type of catheterization, de novo catheters had a lower observed rate of infection than either replacement type (P < or = 0.0001). After controlling for the effect of time, we found that the rate of catheter-related infections associated with a de novo catheter was less than the rate in guidewire exchanged catheters (P = 0.035). Rates of infection were similar between guidewire exchanged catheters and catheters replaced to a new site. CONCLUSION: In a population of ICU patients in whom catheter change was governed by clinical judgement, no differences were noted between the observed rates of infection of new site replacement catheters and guidewire exchange catheters.


Assuntos
Cateterismo Venoso Central/efeitos adversos , Infecções/epidemiologia , Infecções/etiologia , Adulto , Idoso , Cateteres de Demora/efeitos adversos , Estudos de Coortes , Feminino , Humanos , Infecções/microbiologia , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade
18.
Mayo Clin Proc ; 73(9): 895-7, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9737229

RESUMO

Hepatitis C virus (HCV) was recently recognized as a probable etiologic factor for porphyria cutanea tarda (PCT). A review of the literature revealed 40 cases of PCT associated with the human immunodeficiency virus (HIV). In most of these cases, hepatitis C status was unknown. We describe two patients with PCT who were coinfected with HIV and HCV and discuss the interaction of these two viruses. A diagnosis of PCT, especially in a young patient, should prompt investigation for underlying HIV and HCV infection. Porphyrin studies should be performed in any patient with HIV and photosensitivity. Clinicians should be aware of the infectious risk associated with the vesicles and erosions in these patients.


Assuntos
Infecções por HIV/complicações , Hepatite C/complicações , Porfiria Cutânea Tardia/diagnóstico , Porfiria Cutânea Tardia/virologia , Adulto , Diagnóstico Diferencial , Técnica Direta de Fluorescência para Anticorpo , Humanos , Masculino , Pessoa de Meia-Idade
19.
Dis Markers ; 9(3-4): 175-90, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1813209

RESUMO

Serum CA125 measurement has an established role in monitoring epithelial ovarian cancer patients, assisting in determining response to chemotherapy and providing a lead time to clinical relapse. Over the past few years there has been a decrease in the use of second-look laparotomy to determine response; however, this is largely due to the lack of impact that this procedure has on survival rather than the growing use of less invasive scanning techniques or CA 125 assay to determine disease status. The value of a marker lead time depends ultimately on a patient's remaining therapeutic options; the influence on survival of therapeutic intervention at pre-clinical diagnosis of relapse remains to be tested in a randomized controlled trial. The third area where CA 125 may help patient management is in predicting progression-free survival and overall survival. Treating patients with aggressive chemotherapy regimes would not be justified (given the deterioration in the quality of life for a period of months that may result from such therapy) if a poor outcome could be predicted. Deciding when to stop ineffective treatment is extremely difficult for the clinician given patients' desire for active therapy. The prognostic value of CA 125 needs to be further clarified before it can influence such treatment decisions. The aim of this study was to help clarify the role of CA 125 in patient management and to assess several other putative EOC markers, including determinants found on the polymorphic epithelial mucin (PEM)--the most promising alternative marker protein to date.


Assuntos
Antígenos Glicosídicos Associados a Tumores/análise , Biomarcadores Tumorais/análise , Carcinoma/diagnóstico , Neoplasias Ovarianas/diagnóstico , Anticorpos Monoclonais , Carcinoma/tratamento farmacológico , Carcinoma/imunologia , Carcinoma/patologia , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Prognóstico , Análise de Sobrevida
20.
HIV Clin Trials ; 2(2): 160-70, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11590524

RESUMO

BACKGROUND: Therapy of HIV infection with protease inhibitors (PIs) may be associated with improvements in CD4 T-cell number via a mechanism that is independent of effects on plasma viral load (VL). PURPOSE: To compare CD4 responses of patients who receive reverse transcriptase inhibitor (RTI) therapies with or without a PI, matched for viral exposure. METHODS: Patient data were analyzed from two prospective randomized trials of antiviral therapy with or without nelfinavir. Total viral exposure over 24 weeks was estimated by viral area under the curve (AUC), which reflects baseline viral load, slope of virologic decay, viral nadir, and duration of suppression. Patients were stratified into quartiles on the basis of viral AUC, and CD4 T-cell responses were evaluated between PI-containing and RTI-only treatment groups within each quartile. RESULTS: In both trials, patients receiving nelfinavir had greater CD4 T-cell increases than patients receiving RTI alone. Analysis of variance modeling revealed increased CD4 T-cell responses in PI-treated groups at all time points after the second week. These differences were significant (p <.05) at weeks 12, 24, 28, 32, 36, 40, and 48 in one study, and weeks 1, 2, 4, 6, 8, 12, 16, 20, 24, 28, 32, 36, and 44 in the other. Within quartiles matched for viral AUC, absolute CD4 T-cell change from baseline was greater in the PI-treated patients at 84% (101/120) of time points analyzed. CONCLUSION: Nelfinavir-containing therapy is associated with enhanced increases in CD4 T-cell number compared to RTI therapy alone with equivalent antiviral effect. These data suggest that PIs influence CD4 T-cell number through a nonvirologic effect.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1 , Nelfinavir/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Contagem de Linfócito CD4 , Método Duplo-Cego , Quimioterapia Combinada , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/isolamento & purificação , HIV-1/fisiologia , Humanos , Estudos Prospectivos , Carga Viral
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