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2.
Transpl Infect Dis ; 15(5): 510-5, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23930824

RESUMEN

BACKGROUND: Liver transplant recipients are managed with a range of immunosuppressive regimens that place them at heightened risk of life-threatening opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). No routine PJP prophylaxis is used at out institution. We reviewed the incidence of PJP in this cohort of unprophylaxed liver transplant recipients. METHODS: We examined all liver transplants performed between January 2000 and January 2012 in Ireland's National Liver Transplant Centre, St. Vincent's University Hospital, Dublin. Cases were identified through a computerized database and through the histopathology and microbiology registration system. The diagnosis of PJP was confirmed by identification of Pneumocystis cysts in bronchoalveolar lavage (BAL) fluid or on autopsy specimens using Grocott-Gomori methenamine-silver nitrate or modified Wright-Giemsa staining methods. RESULTS: During the study period, 687 liver transplants were performed. We found 7 cases of PJP with an incidence rate of 0.84 per 1000 person transplant years. Five cases occurred within 12 months of transplant with 2 cases occurring at 56 and 60 months, respectively. Two cases were diagnosed at postmortem; 1 previously had negative cytology from BAL, while the other could not be bronchoscoped because of rapid deterioration in the clinical condition. Three of the 5 treated patients died. CONCLUSIONS: The incidence of PJP in this cohort was very low, but the case fatality rate was high. Two cases occurred well after the usual recommended period of prophylaxis. In institutions with a very low risk of infection, targeted rather than universal prophylaxis may be reasonable.


Asunto(s)
Inmunosupresores/uso terapéutico , Trasplante de Hígado/efectos adversos , Infecciones Oportunistas/epidemiología , Pneumocystis carinii/aislamiento & purificación , Neumonía por Pneumocystis/epidemiología , Adulto , Anciano , Estudios de Cohortes , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Infecciones Oportunistas/tratamiento farmacológico , Infecciones Oportunistas/etiología , Neumonía por Pneumocystis/tratamiento farmacológico , Neumonía por Pneumocystis/etiología , Factores de Riesgo
3.
Ir J Med Sci ; 181(1): 49-52, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21853387

RESUMEN

BACKGROUND: Liver disease is an increasing cause of morbidity and mortality in Human immunodeficiency virus (HIV) positive patients. AIM: To describe the first cases of organ transplantation in HIV positive patients in Ireland. METHOD: We report the Irish patients with HIV who received liver transplantation and performed a chart review. RESULT: Two patients received liver transplantation for end stage liver disease caused by Hepatitis C, with survival at 2 years of 100%. CONCLUSION: Liver transplantation is a feasible treatment for patients with HIV and end stage liver disease. The success of transplantation in the HIV positive population should encourage the provision of other medical and surgical interventions previously not offered to patients with HIV.


Asunto(s)
Enfermedad Hepática en Estado Terminal/cirugía , Infecciones por VIH/complicaciones , Hepatitis C Crónica/complicaciones , Cirrosis Hepática/complicaciones , Trasplante de Hígado , Enfermedad Hepática en Estado Terminal/etiología , Infecciones por VIH/tratamiento farmacológico , Humanos , Irlanda , Masculino
4.
J Viral Hepat ; 18(12): 840-51, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22093032

RESUMEN

Dendritic cells (DCs) are likely to play a key role in the compromised T-cell function associated with hepatitis C Virus (HCV) infection. However, studies of DC function in HCV-infected patients to date have yielded conflicting findings possibly because of patient and virus heterogeneity. Here, we report the characterization of monocyte-derived DCs obtained from a homogenous cohort of women who were infected with HCV genotype 1b following exposure to contaminated anti-D immunoglobulin from a single donor source. Patients included in the study had not received anti-viral therapy and all had mild liver disease. We show that phenotypically normal monocyte-derived dendritic cells (MDDCs) (CD11c(+) HLA(-) DR(+) CD1a(+) CD14(lo) ) can be obtained from these patients. These cells respond to both Poly(I:C) and LPS, by up-regulating expression of CD86. They secrete high levels of IL-8 and CCL5 in response to LPS, an indication that the MyD88-dependent and MyD88-independent signalling pathways downstream of TLR4 ligation are functioning normally. However, these cells are poor stimulators of T-cell proliferation in allogeneic mixed lymphocyte reactions. Furthermore, patient MDDCs fail to secrete IFN-α in response to poly(I:C) or IFN-ß stimulation. Altered DC function may contribute to impaired cellular immune responses and chronicity of disease following HCV infection in this cohort. An effective therapeutic vaccine for chronic HCV infection will most likely need to target DCs to elicit an appropriate cellular response; therefore, it is important to resolve how the DCs of different patient cohorts respond to stimulation via TLRs.


Asunto(s)
Proliferación Celular , Células Dendríticas/inmunología , Hepatitis C Crónica/inmunología , Hepatitis C Crónica/patología , Interferón-alfa/metabolismo , Linfocitos T/inmunología , Anciano , Femenino , Humanos , Tolerancia Inmunológica , Masculino , Persona de Mediana Edad
6.
Gut ; 57(8): 1121-8, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18372499

RESUMEN

BACKGROUND: Natural killer (NK) cells may be impaired in patients with persistent hepatitis C virus (HCV) infection, but studies to date have yielded inconsistent findings due to patient and virus heterogeneity and difficulties obtaining appropriate controls. AIMS: To overcome these variables, we have examined numbers, phenotypes, cytotoxic activities and cytokine profiles of circulating NK cells from Irish women who acquired infection through administration of HCV genotype 1b-contaminated anti-D immunoglobulin from a single source and matched controls. RESULTS: Comparing 29 women who developed persistent infection with 21 who spontaneously resolved infection and 26 controls, we found that NK cell numbers were consistently lower in the persistently infected group (p = 0.02 and 0.002). This decrease was due to depletions of NK cells expressing low levels of CD56 (CD56(dim) NK cells; p = 0.004 and 0.0001), whilst CD56(bright) NK cells were expanded (p = 0.004 and 0.0001). Compared to HCV resolvers, CD56(dim) NK cells from persistently infected patients less frequently expressed CD16 and more frequently expressed NKG2A/C/E. These phenotypic changes did not significantly affect natural or interleukin-2-induced cytotoxicity by peripheral blood mononuclear cells against K562 and Daudi targets. Greater frequencies of CD56(bright) NK cells from chronic HCV patients produced interferon-gamma compared with HCV responders (p = 0.05) and controls (p = 0.0001) after phorbol ester stimulation in vitro. CONCLUSIONS: Alterations in NK subset distributions in chronic HCV infection may explain why previous reports of impaired NK cell functions were difficult to confirm. Altered NK cell functions may contribute to impaired cellular immune responses and chronicity of disease following HCV infection.


Asunto(s)
Hepatitis C Crónica/inmunología , Células Asesinas Naturales/inmunología , Adulto , Anciano , Antígeno CD56/sangre , Citotoxicidad Inmunológica , Femenino , Estudios de Seguimiento , Humanos , Inmunidad Celular , Inmunidad Innata , Inmunofenotipificación , Interferón gamma/biosíntesis , Células Asesinas Naturales/citología , Persona de Mediana Edad , Subgrupos de Linfocitos T/inmunología
8.
J Viral Hepat ; 14(4): 255-9, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17381717

RESUMEN

Intrahepatic thrombotic events have been postulated to play a key role in the pathogenesis of hepatic fibrosis. Genetic and acquired thrombotic risk factors may therefore contribute to the varying rates of fibrosis progression observed in patients with chronic hepatitis C virus (HCV) infection. The aim of this study was to assess the impact of inherited mutations in factor V and factor II (prothrombin) on hepatic fibrosis progression rates in individuals infected with HCV. Two hundred and ten Irish women infected with HCV genotype 1b, contracted from a single source (HCV-contaminated anti-D immunoglobulin) were genotyped for the factor V Leiden G1691A and prothrombin G20210A polymorphisms, and compared with Irish Caucasoid controls. Index and subsequent liver biopsies were scored (Ishak scoring system) by a single pathologist. Statistical analysis was performed using SPSS. Factor V Leiden and prothrombin G20210A heterozygosity were determined in 3.7% and 1.85%, respectively, of the study population. There was no association between these polymorphisms and fibrotic score on the index biopsy, or degree of change in fibrotic score on subsequent biopsies. The mean fibrotic score for factor V wild type was 1.06 vs 0.71 for the heterozygotes (P = 0.89). The mean change in fibrotic scores between subsequent biopsies was 0.72 for factor V wild type vs 0.50 for heterozygotes (P = 0.68). Similarly, there was no significant difference in fibrotic score for those with the prothrombin G20210A polymorphism (P = 0.936). Alanine aminotransferase levels for factor V wild type were significantly lower than those for the heterozygotes, 45.9 vs 57 (P = 0.032). Factor V Leiden and prothrombin G20210A heterozygosity rates were infrequently detected in this HCV cohort and were similar to rates seen in a Caucasian Irish control population. In this cohort, neither factor V Leiden nor prothrombin G20210A polymorphisms had a significant impact on fibrotic scores or degree of change between subsequent biopsies. These data do not support a key role for thrombotic risk factors in fibrogenesis in HCV-infected patients.


Asunto(s)
Factor V/genética , Hepacivirus , Hepatitis C Crónica/sangre , Hepatitis C Crónica/genética , Protrombina/genética , Trombosis/genética , Progresión de la Enfermedad , Femenino , Predisposición Genética a la Enfermedad , Hepatitis C Crónica/patología , Humanos , Cirrosis Hepática/genética , Cirrosis Hepática/patología , Cirrosis Hepática/virología
9.
Am J Transplant ; 7(1): 168-76, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17109735

RESUMEN

Acute renal failure (ARF) can complicate up to 60% of orthotopic liver transplants (OLT). The RIFLE criteria were developed to provide a consensus definition for acute renal disease in critically ill patients. Using the RIFLE criteria, we aimed to determine the incidence and risk factors for ARF and acute renal injury (ARI), and to evaluate the link with the outcomes, patient survival and length of hospital stay. Three hundred patients, who received 359 OLTs, were retrospectively analyzed. ARI and ARF occurred post 11.1 and 25.7% of OLTs, respectively. By multivariate analysis, ARI was associated with pre-OLT hypertension and alcoholic liver disease and ARF with higher pre-OLT creatinine, inotrope and aminoglycoside use. ARF, but not ARI, had an impact on 30-day and 1-year patient survival and longer length of hospital stay. ARI and ARF, as defined by the RIFLE criteria, are common complications of OLT, with distinct risk factors and ARF has serious clinical consequences. The development of a consensus definition is a welcome advance, however these criteria do need to be validated in large studies in a wide variety of patient populations.


Asunto(s)
Enfermedades Renales/etiología , Trasplante de Hígado/efectos adversos , Terminología como Asunto , Enfermedad Aguda , Adulto , Femenino , Guías como Asunto , Humanos , Hipertensión , Incidencia , Tiempo de Internación , Hepatopatías Alcohólicas , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Resultado del Tratamiento
10.
Transplant Proc ; 38(7): 2097-8, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16980011

RESUMEN

OBJECTIVES: The King's College Hospital (KCH) criteria are widely used for listing patients with acute liver failure (ALF) for liver transplantation (LT). Recent reports have suggested that the Model for End-Stage Liver Disease (MELD) score may be useful in assessing prognosis in ALF (nonparacetamol). This study compares prognostic accuracy of the two systems in patients with paracetamol (POD)-induced ALF treated in this unit. METHODS: Seventy-two patients (average age 38 years; F:M ratio 2:1) admitted from 1994 to 2005 with POD-related ALF were studied. Clinical and biochemical parameters were recorded. The effect of applying a MELD score of greater than 30 as listing criteria for LT was calculated and compared with the KCH criteria. Outcomes were defined as LT, death, or full recovery. RESULTS: Thirty-one patients (43%) recovered with medical therapy, 29 (40%) patients died, and 12 (17%) underwent LT. Sixty five percent of patients had a MELD > 30 and therefore could potentially be listed on admission; however, using KCH criteria only 24% patients were listed immediately. Sensitivity and negative predictive value of MELD was higher then KCH; however, we found KCH to have much higher specificity and positive predictive value. CONCLUSION: MELD has higher sensitivity and negative predictive value for POD-induced ALF than the KCH criteria. However, the high false-positive rate associated with MELD limits its clinical utility. The high negative predictive value of MELD score may allow it to be used in conjunction with KCH criteria to avoid unneeded LT in patients who will likely recover spontaneously.


Asunto(s)
Fallo Hepático Agudo/clasificación , Fallo Hepático Agudo/cirugía , Trasplante de Hígado/estadística & datos numéricos , Listas de Espera , Adulto , Bilirrubina/sangre , Femenino , Encefalopatía Hepática/clasificación , Encefalopatía Hepática/mortalidad , Encefalopatía Hepática/cirugía , Humanos , Relación Normalizada Internacional , Fallo Hepático Agudo/mortalidad , Fallo Hepático Agudo/terapia , Masculino , Selección de Paciente , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del Tratamiento
11.
Clin Exp Immunol ; 138(1): 94-101, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15373910

RESUMEN

Interleukin 15 (IL-15) is critical for the development of human and murine natural killer (NK) cells and hepatic-derived NK T cells (NKT) in mice, and for the homeostatic maintenance of NK/NKT and CD8(+) memory T cells. The lymphocyte repertoire of an adult human liver includes significant populations of NK and NKT-like cells, which may arise locally from hepatic haematopoietic stem cells (HSCs). We investigated hepatic IL-15 levels and the expression of IL-2/IL-15-receptor beta-chain (IL-2/IL-15Rbeta; CD122) on mature hepatic lymphocytes and HSCs. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect secreted/intracellular IL-15 transcripts. IL-15 protein was localized using immunohistochemistry; levels were measured by enzyme-linked immunosorbent assay IL-2/IL-15Rbeta expression by flow-cytometry. Normal hepatic IL-15 protein was detected at 0.43 ng/100 mg total protein (n = 11, range 0.10 ng-0.9 ng). There was a significant increase in HCV-infected tissue (1.78 ng, P < 0.005, n = 11, range 0.18-2.43 ng). The staining pattern suggests that infiltrating monocytes and tissue resident Kupffer cells are the main producers. IL-15 protein was detected in supernatants from cultured liver biopsy specimens in the absence of stimulation (mean 175.8 pg/100 mg wet tissue, n = 3), which increased significantly upon stimulation (P < 0.05, mean 231.21 pg). On average, 61% of hepatic HSCs expressed IL-2/IL-15Rbeta suggesting a local lymphopoietic role. Eighty per cent of NK and 45.8% of CD56(+) T cells expressed IL-2/IL-15Rbeta, suggesting involvement in local CD56(+) cell activation and expansion. Constitutive expression of IL-15 protein and IL-2/IL-15Rbeta on hepatic lymphocytes suggests a key role in the generation and maintenance of the unique hepatic lymphoid repertoire. The significant increase observed in HCV-infected liver suggests a role for IL-15 in host antiviral responses in the liver.


Asunto(s)
Interleucina-15/análisis , Células Asesinas Naturales/inmunología , Hígado/inmunología , Linfocitos T/inmunología , Adolescente , Adulto , Anciano , Antígenos CD/inmunología , Femenino , Células Madre Hematopoyéticas/inmunología , Humanos , Inmunohistoquímica/métodos , Interleucina-2/análisis , Masculino , Persona de Mediana Edad , ARN Mensajero/análisis , Receptores de Interleucina-2/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos
12.
J Immunol ; 167(6): 3129-38, 2001 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11544298

RESUMEN

IL-2 and IL-15 are lymphocyte growth factors produced by different cell types with overlapping functions in immune responses. Both cytokines costimulate lymphocyte proliferation and activation, while IL-15 additionally promotes the development and survival of NK cells, NKT cells, and intraepithelial lymphocytes. We have investigated the effects of IL-2 and IL-15 on proliferation, cytotoxicity, and cytokine secretion by human PBMC subpopulations in vitro. Both cytokines selectively induced the proliferation of NK cells and CD56(+) T cells, but not CD56(-) lymphocytes. All NK and CD56(+) T cell subpopulations tested (CD4(+), CD8(+), CD4(-)CD8(-), alphabetaTCR(+), gammadeltaTCR(+), CD16(+), CD161(+), CD158a(+), CD158b(+), KIR3DL1(+), and CD94(+)) expanded in response to both cytokines, whereas all CD56(-) cell subpopulations did not. Therefore, previously reported IL-15-induced gammadelta and CD8(+) T cell expansions reflect proliferations of NK and CD56(+) T cells that most frequently express these phenotypes. IL-15 also expanded CD8alpha(+)beta(-) and Valpha24Vbeta11 TCR(+) T cells. Both cytokines stimulated cytotoxicity by NK and CD56(+) T cells against K562 targets, but not the production of IFN-gamma, TNF-alpha, IL-2, or IL-4. However, they augmented cytokine production in response to phorbol ester stimulation or CD3 cross-linking by inducing the proliferation of NK cells and CD56(+) T cells that produce these cytokines at greater frequencies than other T cells. These results indicate that IL-2 and IL-15 act at different stages of the immune response by expanding and partially activating NK receptor-positive lymphocytes, but, on their own, do not influence the Th1/Th2 balance of adaptive immune responses.


Asunto(s)
Interleucina-15/farmacología , Interleucina-2/farmacología , Células Asesinas Naturales/efectos de los fármacos , Activación de Linfocitos/efectos de los fármacos , Receptores de Neuroquinina-1/metabolismo , Subgrupos de Linfocitos T/efectos de los fármacos , Antígeno CD56/análisis , División Celular/efectos de los fármacos , Reordenamiento Génico de Linfocito T , Humanos , Inmunofenotipificación , Interferón gamma/biosíntesis , Interferón gamma/genética , Interleucina-2/biosíntesis , Interleucina-2/genética , Interleucina-4/biosíntesis , Interleucina-4/genética , Células K562 , Células Asesinas Naturales/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Proteínas Recombinantes/farmacología , Subgrupos de Linfocitos T/inmunología , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/genética
13.
Cytokine ; 14(3): 143-51, 2001 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-11396992

RESUMEN

Interleukin-7 (IL-7) has been shown to play an essential role in T-cell development. Recombinase-activating gene (RAG)-1, RAG-2 and pre-TCR-alpha expression in the normal adult human liver (AHL), together with the presence of lymphoid-haematopoietic progenitors, is strong evidence that the AHL supports T cell maturation. We investigated IL-7 mRNA and protein levels in order to determine whether AHL could support T lymphocyte differentiation. Biopsies were snap frozen, powdered, and RNA/protein extracted. Reverse transcriptase polymerase chain reaction was used to detect IL-7 using primers that amplified 620 base pair (bp) fragments and other smaller transcripts. A sandwich enzyme-linked immunosorbent assay was developed to quantify IL-7 protein in homogenates. The anatomic distribution of IL-7-secreting cells was determined by immunohistochemistry. IL-7-specific product (620 bp) was detected in nine of ten samples, with six also positive for a smaller splice-variant (488 bp). Levels of the 620 bp product were 2.5 times greater than the 488 bp fragment. IL-7 protein was detected in all samples (range 18.47-76.93 pg/100 mg tissue). Immunohistochemistry demonstrated IL-7 protein in discrete cells of lymphoid morphology, widely distributed throughout the parenchyma and within portal tracts. Large populations of innate T cells are found in normal AHL, some of which may differentiate locally. The presence of IL-7 RNA and protein throughout normal hepatic tissue provides evidence that the normal AHL is a suitable microenvironment for T cell differentiation.


Asunto(s)
Interleucina-7/biosíntesis , Hígado/metabolismo , ARN Mensajero/biosíntesis , Linfocitos T/citología , Timo/citología , Timo/metabolismo , Adulto , Anciano , Diferenciación Celular/inmunología , Femenino , Humanos , Inmunohistoquímica , Interleucina-7/genética , Interleucina-7/metabolismo , Hígado/citología , Hígado/inmunología , Masculino , Persona de Mediana Edad , Linfocitos T/inmunología , Linfocitos T/metabolismo , Timo/inmunología , Transcripción Genética/inmunología , Células Tumorales Cultivadas
14.
J Immunol Methods ; 242(1-2): 21-31, 2000 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-10986386

RESUMEN

Murine and human studies have demonstrated that the normal liver contains significant numbers of resident lymphocytes that have functions distinct from those found in blood and other organs. To characterize these cells requires the isolation of viable lymphocytes that can be analysed by flow cytometry and in functional assays. The techniques classically used to isolate single cell suspensions of hepatic lymphocytes for phenotypic and functional studies involve mechanical and/or enzymatic dissociation of liver tissue. The aim of this study was to determine the effect of these procedures on surface molecule expression and lymphocyte function and to optimise an isolation technique that minimises these effects. Mechanical homogenisation of liver tissue alone resulted in low viable lymphocyte yields but these were improved by the combined use of mechanical and enzymatic techniques. A mean yield of 2.3 x 10(6) lymphocytes with a mean viability was 88.8% was obtained from 200 mg wedge biopsy samples of normal adult human liver using a combination of gentle mechanical dissociation followed by digestion with collagenase type IV and DNase I. These cells were suitable for phenotypic characterisation by flow cytometry. They also retained their ability to grow in vitro, to respond to cytokines and activation stimuli, to mediate cytotoxic killing of target cells, and to produce inflammatory and regulatory cytokines.


Asunto(s)
Separación Celular , Hígado/citología , Linfocitos/clasificación , Linfocitos/inmunología , Soluciones Preservantes de Órganos , Adenosina , Adulto , Alopurinol , Animales , Biomarcadores , Separación Celular/métodos , Separación Celular/normas , Supervivencia Celular , Células Cultivadas , Pruebas Inmunológicas de Citotoxicidad , Endopeptidasas/metabolismo , Glutatión , Humanos , Inmunofenotipificación , Insulina , Interferón gamma/biosíntesis , Interleucina-4/biosíntesis , Células K562 , Linfocitos/citología , Ratones , Rafinosa
15.
Hepatology ; 31(6): 1251-6, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10827150

RESUMEN

The presence and phenotype of lineage-committed hematopoietic progenitors in the normal adult human liver (AHL) were investigated and compared with the profiles of differentiating hematopoietic precursor populations detected in liver bearing metastases of colonic origin. Levels of hematopoietic stem cells (HSCs) (CD34(+)CD45(+)) detected in hepatic mononuclear cell (HMNC) populations were increased 6-fold when compared with matched peripheral blood samples. In normal liver, less than 5% of HSCs expressed the myeloid-associated antigen, CD33, whereas considerable proportions expressed lymphoid-associated markers (T cell, 33.39%; B cell, 17.39%; and natural killer [NK] cell, 37.17%). Significant increases were observed in the relative proportions of hepatic HSCs coexpressing CD33 (20.53%; P =.001), and the T-cell marker (CD7, 58. 13%; P =.02) in tumor-bearing liver compared with normal liver. HSCs with B-cell progenitor phenotype (CD19(+)) were significantly decreased in tumor-bearing liver (0.06%; P =.02). Despite these differences, the activation status of hematopoiesis, as measured by the coexpression of the differentiation and activation markers, CD38 and CD45RA, did not differ significantly between normal and tumor-bearing liver. These results indicate that the normal AHL harbors lineage-committed hematopoietic progenitors, and the vast majority of these progenitors express lymphoid-associated antigens with changes occurring in both the myeloid and lymphoid compartments of the hepatic hematopoietic pathway on tumor challenge. While tumor-bearing livers are enriched for intrahepatic myeloid precursors and T-cell progenitor cells, further studies are required to establish the origin and in situ development potential of hepatic HSCs in the adult human and their role in tumor immunity.


Asunto(s)
Médula Ósea/metabolismo , Células Madre Hematopoyéticas/metabolismo , Neoplasias Hepáticas/metabolismo , Tejido Linfoide/metabolismo , Adolescente , Adulto , Anciano , Biomarcadores , Diferenciación Celular , Senescencia Celular , Femenino , Células Madre Hematopoyéticas/patología , Células Madre Hematopoyéticas/fisiología , Humanos , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Valores de Referencia
16.
J Hepatol ; 32(1): 121-5, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10673076

RESUMEN

BACKGROUND/AIMS: Hepatitis C virus (HCV) infection is associated with the development of chronic liver disease and extra-hepatic manifestations, which include autoantibody production, immune-mediated diseases such as cryoglobulinaemia and B-cell lymphoproliferation. Recent identification of intra-hepatic clonal B cells capable of rheumatoid factor production, selective infection of B cells over T cells and of an HCV receptor on B lymphocytes strongly supports a central role for these cells in the immune response to HCV infection. In particular, CD5+ B cells which are capable of producing natural antibodies with autoreactive specificities are likely to be important in the development of HCV-associated autoimmunity and lymphoproliferation. METHODS: We have investigated the presence of CD5+ B cells in a unique cohort of HCV-infected women who were infected with a single inoculum of HCV genotype 1b following immunisation with contaminated anti-D immunoglobulin in 1977. RESULTS: CD5+ B cells are significantly increased in chronic HCV infection (37.66+/-1.92%) as compared with those with resolved infection (25.33+/-1.90%). High levels of CD5+ B cells were associated with the production of rheumatoid factor. The number of peripheral blood CD5+ B cells correlated negatively with histological activity index. CONCLUSIONS: The expansion of this B cell population in patients with active HCV infection may give rise to immune-mediated sequelae associated with HCV infection. This expanded population of CD5+ B cells may protect against the development of progressive liver disease.


Asunto(s)
Linfocitos B/inmunología , Antígenos CD5/inmunología , Hepacivirus/inmunología , Hepatitis C Crónica/inmunología , Adulto , Antígenos CD19/análisis , Femenino , Citometría de Flujo , Hepacivirus/genética , Hepatitis C Crónica/sangre , Hepatitis C Crónica/patología , Humanos , Hígado/inmunología , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , ARN Viral/análisis , Factor Reumatoide/sangre
17.
J Immunol ; 163(4): 2314-21, 1999 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-10438977

RESUMEN

The human liver contains significant numbers of T cells, NK cells, and lymphocytes that coexpress T and NK cell receptors. To evaluate their functional activities, we have compared the cytotoxic activities and cytokines produced by normal adult hepatic CD3+CD56- (T) cells, CD3-CD56+ (NK) cells, and CD3+CD56+ (natural T (NT)) cells. In cytotoxicity assays using immunomagnetic bead-purified NK cell, T cell, and NT cell subpopulations as effectors, fresh hepatic NK cells lysed K562 targets, while NT cells could be induced to do so by culturing with IL-2. Both NT and T cells were capable of redirected cytolysis of P815 cells using Abs to CD3. Flow cytometric analysis of cytokine production by fresh hepatic lymphocyte subsets activated by CD3 cross-linking or PMA and ionomycin stimulation indicated that NT cells and T cells could produce IFN-gamma, TNF-alpha, IL-2, and/or IL-4, but little or no IL-5, while NK cells produced IFN-gamma and/or TNF-alpha only. The majority of NT cells produced inflammatory (Th1) cytokines only; however, approximately 6% of all hepatic T cells, which included 5% of Valpha24 TCR-bearing NT cells and 2% of gammadeltaTCR+ cells, simultaneously produced IFN-gamma and IL-4. The existence of such large numbers of cytotoxic lymphocytes with multiple effector functions suggests that the liver is an important site of innate immune responses, early regulation of adaptive immunity, and possibly peripheral deletion of autologous cells.


Asunto(s)
Citocinas/metabolismo , Citotoxicidad Inmunológica , Hígado/citología , Hígado/inmunología , Subgrupos Linfocitarios/inmunología , Adulto , Complejo CD3/biosíntesis , Antígeno CD56/biosíntesis , Separación Celular , Células Cultivadas , Humanos , Células Asesinas Activadas por Linfocinas/inmunología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Hígado/metabolismo , Subgrupos Linfocitarios/metabolismo , Receptores de Antígenos de Linfocitos T/fisiología , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismo , Células TH1/metabolismo , Células Th2/metabolismo
18.
Calcif Tissue Int ; 64(4): 295-300, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10089221

RESUMEN

Hepatic osteodystrophy occurs in up to 50% of patients with chronic liver disease (CLD). The aim of this study was to determine the relative contribution of increased resorption and decreased formation to hepatic osteodystrophy by measuring biochemical markers. Twenty-seven patients with advanced CLD (14 female, 13 male) were enrolled. Bone mineral density (BMD), measured at the lumbar spine, and femoral neck, were measured by dual energy X-ray absorptiometry (DXA); bone turnover was assessed using biochemical markers of bone formation and resorption. Based on WHO criteria, osteoporosis and osteopenia were present in 41% and 18% of patients, respectively. All three markers of bone resorption (free deoxypyridinoline, pyridinoline, and hydroxyproline) were increased significantly in patients with CLD. There was a less marked change in the markers of bone formation (osteocalcin, procollagen type 1 peptide, and bone alkaline phosphatase), resulting in a negative uncoupling index in 23/27 (85%) of the patients. Only two (7%) patients had biochemical changes consistent with osteomalacia. The results suggest that increased bone resorption is the predominant cause of hepatic osteodystrophy and therapeutic strategies should be designed to suppress bone resorption, especially in preparation for liver transplantation. Bone biomarkers may be useful alternatives to bone biopsy in evaluating hepatic osteodystrophy.


Asunto(s)
Desmineralización Ósea Patológica/fisiopatología , Densidad Ósea , Remodelación Ósea/fisiología , Hepatopatías/fisiopatología , Vitamina D/metabolismo , Absorciometría de Fotón , Adulto , Anciano , Biomarcadores/análisis , Calcifediol/análisis , Calcio/análisis , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo
19.
Hepatology ; 29(4): 1193-8, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10094964

RESUMEN

Previous studies have identified novel lymphoid phenotypes in the adult human liver and provided evidence to suggest that lymphoid differentiation can occur locally in this organ. The aim of this study was to examine the adult human liver for the presence of hematopoietic stem cells that may provide the necessary precursor population for local hematopoietic and lymphoid differentiation. Hepatic mononuclear cells (HMNC) were extracted from normal adult liver biopsy specimens using a combination of mechanical disruption and enzymatic digestion. The stem cell marker CD34 was found on 0.81% to 2.35% of isolated HMNCs by flow cytometry. CD34(+) HMNCs were positively selected using magnetically labeled beads, and the enriched population was further examined for surface markers characteristically expressed by immature hematopoietic cells and early progenitors. CD45 was expressed by 49% (+/-23%) of CD34(+) HMNCs, indicating their hematopoietic origin. CD38, one of the first markers to be expressed by developing progenitor cells was found on 50% (+/-22%) of CD34(+) HMNCs indicating the presence of both pluripotent stem cells and committed precursors. The majority (90%) of CD34(+) HMNCs coexpressed the activation marker human leukocyte antigen DR, consistent with actively cycling cells. Functional maturation of these hepatic progenitors was shown by the detection of multilineage hematopoietic colony formation after tissue culture. Erythroid (BFU-E), granulocyte-monocyte (CFU-GM), and mixed colonies (CFU-GEMM) were detected after culture of unseparated HMNCs and the enriched CD34(+) HMNC population; 14.3 +/- 13.2 (mean +/- SD) BFU-E, 3.1 +/- 3.1 CFU-GM, and 0.4 +/- 0.9 CFU-GEMM per 1 x 10(5) unseparated HMNCs and 16.0 +/- 9.5 BFU-E and 1.7 +/- 0.9 CFU-GM were identified per 2.4 x 10(3) CD34(+) HMNCs plated. The detection of surface markers characteristic of immature hematopoietic cells and colony formation in tissue culture provides evidence for the presence of hematopoietic stem cells and early progenitor cells in the adult human liver. This would suggest that the adult human liver continues to contribute to hematopoiesis and may be an important site for the differentiation of lymphohematopoietic cells involved in disease states, such as autoimmune hepatitis and graft rejection after liver transplantation.


Asunto(s)
Células Madre Hematopoyéticas/citología , Hígado/citología , Antígenos CD/metabolismo , Antígenos CD34/metabolismo , Separación Celular , Células Cultivadas , Células Precursoras Eritroides/citología , Células Precursoras Eritroides/metabolismo , Granulocitos/metabolismo , Células Madre Hematopoyéticas/metabolismo , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/metabolismo , Hígado/metabolismo , Macrófagos/metabolismo
20.
Gut ; 44(3): 430-4, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10026333

RESUMEN

BACKGROUND: Hepatic osteodystrophy occurs in the majority of patients with advanced chronic liver disease with the abnormalities in bone metabolism accelerating following orthotopic liver transplantation (OLT). AIMS: To examine changes in bone mineral density (BMD) following OLT and to investigate factors that lead to bone loss. METHODS: Twelve patients had BMD (at both the lumbar spine (LS) and femoral neck (FN)) and biochemical markers measured preoperatively and for 24 months following OLT. RESULTS: BMD was low in 75% of patients prior to OLT and decreased significantly from baseline at the LS at three months and the FN at six months. BMD began to increase thereafter at both sites, approaching baseline values at the LS by 12 months. Bone formation markers, osteocalcin and procollagen type I carboxy propeptide, decreased immediately post-OLT, with a concomitant increase seen in the resorption markers pyridinoline and deoxypyridinoline. This resulted in a negative uncoupling index early post-OLT, that rebounded to positive values after six months. There was a significant correlation between the change in the uncoupling index between six and three months which preceded the increase in BMD at 12 months. The decrease in BMD recorded early post-OLT correlated with vitamin D levels at three months. CONCLUSIONS: Results suggest that increased resorption and inadequate formation are the major contributors to additional bone loss following OLT. Non-invasive biochemical markers precede later changes in BMD in this patient group following OLT and may have a role in investigating and planning intervention strategies to prevent bone loss in future studies.


Asunto(s)
Hepatopatías/complicaciones , Osteólisis/etiología , Anciano , Biomarcadores , Densidad Ósea , Huesos/metabolismo , Femenino , Humanos , Hepatopatías/metabolismo , Hepatopatías/cirugía , Trasplante de Hígado , Masculino , Persona de Mediana Edad , Osteólisis/metabolismo
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