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Antiinflamatorios no Esteroideos/uso terapéutico , Antagonistas del Receptor de Bradiquinina B2/uso terapéutico , Bradiquinina/análogos & derivados , Tratamiento Farmacológico de COVID-19 , Bradiquinina/uso terapéutico , COVID-19/diagnóstico , COVID-19/fisiopatología , Humanos , Pulmón/efectos de los fármacos , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , SARS-CoV-2 , Resultado del TratamientoRESUMEN
As a fraction of ingested ethanol is metabolized by gastric mucosa, different amounts of alcohol should reach the liver when the same dose is administered by oral or intravenous route. Therefore, we investigated the time-course of hepatic reduced glutathione (GSH) concentrations after intra-peritoneal or intra-gastric load of the same amount of ethanol in the rat. The test was also performed in fasted and Cimetidine-treated rats. The oral ethanol administration was followed by a less pronounced decrease and by a quicker recovery of hepatic content of GSH than after intraperitoneal route. In the fasted rat, basal hepatic GSH significantly decreased; after alcohol administration the decrease of hepatic GSH was more severe and prolonged than in the fed rat. Cimetidine was shown to be a potent inhibitor of gastric ADH. Pre-treatment with Cimetidine did not change the basal levels of hepatic GSH, but after oral ethanol load, the decrease of the hepatic GSH content was significantly (p < 0.005) more pronounced than in controls. This study demonstrates the beneficial effects of gastric ethanol metabolism on the liver. The reduced gastric ethanol metabolism, induced by fasting or by Cimetidine resulted in a decreased content and delayed recovery of liver GSH content.
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Etanol/metabolismo , Glutatión/metabolismo , Hígado/metabolismo , Animales , Cimetidina/farmacología , Citosol/metabolismo , Ayuno , Masculino , Ratas , Ratas WistarRESUMEN
BACKGROUND: Myelodysplastic syndromes (MDS) are a group of disorders characterized by ineffective and dysplastic haemopoiesis. Previous studies in the lab have shown extensive apoptosis and high levels of transforming growth factor (TGF-beta) and tumor necrosis factor (TNF-alpha) in the stromal layer of MDS bone marrow. The current study focuses on the cytokines expressed in the bone marrow parenchymal cells. MATERIALS AND METHODS: Bone marrow aspirate from 5 normal donors and 26 patients with myelodysplastic syndromes were examined for mRNA expression of tumor necrosis factor alpha (TNF-alpha), macrophage colony stimulating factor (M-CSF), Flt-3 Ligand (Flt-3L), Flt-3 receptor(Flt-3 rec), interleukin 1 beta (IL 1 beta) and interleukin 1 receptor antagonist (IL-1 ra). RESULTS: Comparison of 26 MDS marrows with 5 normals showed a significantly higher value for Flt-3 rec and IL 1 beta (p = 0.031 and p = 0.031) in the former, while only Flt-1 beta rec was considerably higher (p = 0.016) in newly diagnosed patients. In previously diagnosed group, Flt-3 rec (p = 0.001), TNF-alpha (p = 0.04) and IL-1 beta (p = 0.016) were higher than normal while there was no statistically significant difference in the newly versus previously diagnosed MDS cases: CONCLUSION: mRNA expression of all six cytokines measured were considerably higher in MDS when compared to normal and that these levels tend to increase with disease duration. The precise source of these cytokines as well as their role in MDS pathogenesis remains to be determined, but this study confirms our previous reports that there is no dearth of cytokines in these bizarre myelosuppressive states.
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Médula Ósea/metabolismo , Citocinas/genética , Síndromes Mielodisplásicos/genética , ARN Mensajero/genética , Receptores de Citocinas/genética , Adulto , Anciano , Secuencia de Bases , Niño , Cartilla de ADN , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
OBJECTIVE: To evaluate serum levels of prolyl-hydroxylase and helical domain of Type IV collagen, markers of hepatic fibrogenesis, in patients with HCV-positive chronic liver disease and the effects of interferon therapy on these markers. DESIGN: Prolyl-hydroxylase and Type IV collagen were determined before therapy and each month during the treatment and follow-up. METHODS: Fifty-seven HCV-positive patients were studied. All the subjects received alpha2a recombinant interferon, 6 MU subcutaneously three times a week for 4 weeks, followed by 3 MU thrice weekly for 5 months. After cessation of treatment, each patient was followed for 12 months. Prolyl-hydroxylase and helical domain of Type IV collagen were measured by using immunoenzymatic methods. HCV-RNA and HCV genotype were determined according to the method of Okamoto. RESULTS: In the patients prolyl-hydroxylase (39.8+/-8.9 ng/ml) was not different from controls (39.1+/-5.9 ng/ml). On the contrary, the patients showed a mean Type IV collagen (133.6+/-93.3 ng/ml) significantly (P < 0.01) higher than controls (100.2+/-10.5 ng/ml). A good relationship between the degree of liver fibrosis and the Type IV collagen serum level was found (r = 0.68; P < 0.005). In both responders and non-responders the Type IV collagen levels decreased during interferon therapy. During the follow-up, in responders the Type IV collagen did not show modifications, while in non-responders/relapsers it returned rapidly to the pretreatment levels (139.1+/-100.7 ng/ml). CONCLUSION: In HCV-positive chronic liver disease, prolylhydroxylase is not a good marker of hepatic fibrosis, while Type IV collagen is a useful tool for evaluating fibrogenic activity. Interferon seems to be able to reduce the liver fibrosis even without the inhibition of viral replication and independently from liver necrosis.
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Colágeno/sangre , Hepatitis C/sangre , Interferón-alfa/uso terapéutico , Cirrosis Hepática/sangre , Procolágeno-Prolina Dioxigenasa/sangre , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Femenino , Genotipo , Hepacivirus/aislamiento & purificación , Hepatitis C/tratamiento farmacológico , Hepatitis Crónica/sangre , Hepatitis Crónica/tratamiento farmacológico , Humanos , Interferón alfa-2 , Cirrosis Hepática/tratamiento farmacológico , Masculino , Persona de Mediana Edad , ARN Viral/análisis , Proteínas RecombinantesRESUMEN
AIM: To assess the efficacy of different schedules of human leucocyte interferon alpha in chronic hepatitis C. PATIENTS AND METHODS: A total of 213 naive patients with chronic hepatitis C were treated with 4 different schedules of human leucocyte interferon alpha. Sustained response was defined as persistently normal alanine amino transferase values with negative serum hepatitis C virus-RNA up to 12 months after therapy withdrawal. RESULTS: Rates of sustained response were 16% with 3 MU tiw for 6 months, 33% with 6 MU tiw for 5 months after a priming dose of 9 MU tiw for a month, 32% with 3 MU tiw for 12 months and 20% with 3 MU daily for 6 months. The major factors affecting the response rate were age and the hepatitis C virus genotype, as a sustained response was significantly higher in patients under 45 years and infected by hepatitis C virus types other than hepatitis C virus-1. Treatment was well tolerated and side-effects and drop-out events were similar to those described with other types of alpha-interferons. CONCLUSIONS: Human leucocyte interferon alpha appears to be equivalent to recombinant interferon-alpha in the treatment of chronic hepatitis C.
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Antivirales/uso terapéutico , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Alanina Transaminasa/sangre , Antivirales/administración & dosificación , Esquema de Medicación , Femenino , Humanos , Interferón-alfa/administración & dosificación , Masculino , Persona de Mediana Edad , Análisis Multivariante , ARN Viral/sangre , Factores de TiempoRESUMEN
As a fraction of ingested ethanol (EtOH) is metabolized by gastric mucosa, different amounts of alcohol reach the liver, when the same dose is administered by oral or intravenous route. In previous experiments, we demonstrated that the decrease of hepatic reduced glutathione (GSH) is less pronounced and is followed by a quicker recovery after oral than after intraperitoneal administration of the same amount of EtOH. Therefore, the time-course of hepatic GSH concentration seems to be an indirect assay of EtOH metabolism by the liver. On the basis of these findings, any condition causing a reduced function of gastric alcohol dehydrogenase (ADH) should show up as a more severe depletion of hepatic GSH. In the same rat experimental model we determined the effects of cimetidine and omeprazole administration on gastric ADH activity and on the time-course of hepatic GSH after EtOH load. Cimetidine was shown to inhibit gastric ADH with a Ki of 0.167 +/- 0.009 mmol l-1; accordingly, the pretreatment with this drug (20 mg kg-1 b.w. per day for 1 week) determined, after oral EtOH load, a marked reduction of hepatic GSH, likewise after intraperitoneal administration. Omeprazole exerted only a marginal inhibition on gastric ADH and this drug (0.3 mg kg-1 b.w. per day for 1 week) did not modify the time-course of hepatic GSH concentrations after EtOH load. This study indicates that the inhibition of gastric ADH, when associated with EtOH intake, induces depletion of the hepatic GSH concentration and, therefore, possible liver damage.
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Cimetidina/farmacología , Etanol/farmacología , Glutatión/efectos de los fármacos , Hígado/efectos de los fármacos , Omeprazol/farmacología , Administración Oral , Animales , Relación Dosis-Respuesta a Droga , Glutatión/metabolismo , Hígado/metabolismo , Masculino , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
OBJECTIVES: As a close relationship has been established between mixed cryoglobulinaemia and hepatitis C virus (HCV) infection, the clinical, histological and virological findings of patients affected by mixed cryoglobulinaemia were determined. DESIGN: Hepatitis C virus infection was investigated by the presence of anti-HCV antibodies and PCR amplification of the 5' untranslated region (5' UTR), and the genotype of HCV was also determined according to Okamoto. A bone marrow biopsy was performed in all patients and liver and kidney biopsies when indicated. SUBJECTS: Eighty-two subjects affected by mixed cryoglobulinaemia were enrolled in this study. RESULTS: The prevalence of anti-HCV antibodies was high (83%); PCR amplification of the 5'UTR region was performed in 52 subjects and in 44 of them (85%) the results were positive. In the same subjects, the Core region amplification was positive in 46 cases (88%). A high prevalence of genotype II was found (54%). Chronic liver disease was present in 55 patients (67%). Bone marrow biopsies showed the presence of low-grade non-Hodgkin's lymphomas in 11 cases (13%). Membrano-proliferative glomerulonephritis was found in seven subjects (8%). CONCLUSIONS: Mixed cryoglobulinaemia is associated with HCV infection in the nearly all cases. Several HCV genotypes are involved in the pathogenesis of this disease. Mixed cryoglobulinaemia is associated with a high prevalence of chronic liver disease, low-grade non-Hodgkin's lymphomas and membrano-proliferative glomerulonephritis.
Asunto(s)
Crioglobulinemia/etiología , Hepatitis C/complicaciones , Anciano , Análisis de Varianza , Secuencia de Bases , Crioglobulinemia/genética , Crioglobulinemia/inmunología , Crioglobulinemia/patología , Crioglobulinemia/virología , Femenino , Genotipo , Anticuerpos Antihepatitis/sangre , Hepatitis C/genética , Hepatitis C/inmunología , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Fenotipo , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/aislamiento & purificación , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: Since a large fraction of patients affected by chronic hepatitis C do not respond to alpha-interferon therapy, we planned a pilot study of intravenous beta-interferon therapy in Italian patients non responsive to several courses of alpha-interferon. METHODS: Ten Italian patients with chronic hepatitis C were treated intravenously with beta-interferon to assess the biochemical and virological responses. Each patient received intravenously 6 MU of beta-interferon daily for 7 days a week for a period of 2 months; in responders, this treatment was followed by intramuscular beta-interferon administration 6 MU three times a week for an additional 8 weeks. RESULTS: All the patients were infected by the genotype 1b of hepatitis C virus and had a high serum concentration of HCV-RNA (4.1 +/- 3.3 x 10(7) copies/ml). During intravenous therapy, 4 patients (40%) showed a complete return to normal of alanino-aminotransferase and 3 cases became HCV-RNA negative. During intramuscular beta-interferon administration, two patients breakthrough. At the end of the follow-up (six months after the end of the treatment) two patients only showed return to normal of alanino-aminotransferase, but one of them remained HCV-RNA positive. CONCLUSIONS: These results indicate that even genotype 1b of hepatitis C virus can be suppressed by intravenous beta-interferon therapy, as previously described in similar cases in Japan. The rate of sustained biochemical and virologic response was, however, low, suggesting that further studies are needed to define the best regimen to achieve eradication of hepatitis C virus infection.
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Antivirales/uso terapéutico , Hepatitis C Crónica/terapia , Interferón-alfa/uso terapéutico , Interferón beta/uso terapéutico , Adulto , Alanina Transaminasa/sangre , Antivirales/administración & dosificación , Antivirales/efectos adversos , Ensayo de Inmunoadsorción Enzimática , Femenino , Genoma Viral , Hepacivirus/genética , Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/análisis , Hepatitis C Crónica/sangre , Hepatitis C Crónica/diagnóstico , Humanos , Infusiones Intravenosas , Interferón beta/administración & dosificación , Interferón beta/efectos adversos , Italia , Masculino , Persona de Mediana Edad , Proyectos Piloto , Reacción en Cadena de la Polimerasa , ARN Viral/análisis , Seguridad , Resultado del TratamientoRESUMEN
A higher percentage of apoptotic cells (apoptotic index or AI) is consistently found in bone marrow (BM) biopsies compared to BM aspirates of patients with myelodysplastic syndrome (MDS). Most studies have only investigated the low-density fraction (LDF) mononuclear cells from BM aspirates following density separation for AI determination. In the present study, both LDF and high-density fraction (HDF) cells for AI were examined by electron microscopy (EM) in 10 MDS patients and 4 healthy donors. Matched BM biopsies were subjected to AI detection by in situ end labeling (ISEL) of fragmented DNA. The results indicate that in LDF and HDF cells, AI is consistently higher in MDS patients (8.5% vs 1.5%, respectively; P =.039) compared to healthy donors (27% vs 4%, respectively; P =. 004). The BM biopsy AI was also higher in MDS patients than in healthy donors (3+ vs 0+, respectively; P =.036). In addition, in MDS patients, more apoptotic cells were found in HDF cells than in LDF cells (27% vs 8.5%, respectively;P =.0001). All stages of maturation, ranging from blasts to terminally mature cells belonging to all 3 lineages, were represented in the dying cells in both compartments. Using EM, typical Pelger-Huett-type cells appeared to be apoptotic granulocytes. Both LDF and HDF cells should be examined for an accurate estimation of apoptotic cells because AI would be underestimated if only the LDF cells were studied. Ultrastructural studies consistently show a higher AI in BM biopsies compared to BM aspirates despite the correction factor of HDF cells provided by AI. This may represent the actual extant state, which could conceivably be due to a higher concentration of proapoptotic signals in the biopsies. (Blood. 2000;96:1388-1392)
Asunto(s)
Apoptosis , Células de la Médula Ósea/patología , Síndromes Mielodisplásicos/patología , Células de la Médula Ósea/ultraestructura , Recuento de Células , Fragmentación del ADN , Humanos , Microscopía ElectrónicaRESUMEN
BACKGROUND: The severity, clinical course, and risk of hepatitis C virus (HCV) related chronic liver disease are still rather poorly defined. AIMS: To investigate the prevalence, risk factors, and severity of HCV related liver disease in the general population, and investigate whether infection with a specific genotype is associated with an increased risk of cirrhosis or hepatocellular carcinoma. METHODS: HCV RNA determination by polymerase chain reaction (PCR) and HCV genotyping were performed in all anti-HCV positive subjects belonging to the Dionysos study (6917 subjects). Diagnosis of cirrhosis and hepatocellular carcinoma was established by liver biopsy in all cases. All the data were analysed by univariate and multivariate statistics in all the cohort. To investigate the natural history of HCV infection, anti-HCV positive subjects were followed up every six months for three years with liver function tests and ultrasonograms. RESULTS: The overall prevalence of HCV RNA positivity was 2.3%. Positivity increased progressively with age, and was higher in women (ratio of men to women = 0.7). Genotypes 1b and 2a were the most frequent (42 and 24% of HCV RNA positive patients), with a prevalence of 1 and 0.6% respectively. Intravenous drug use, blood transfusions received before 1990, history of previous hepatitis among the cohabiting, and history of animal (mainly dogs) bites were significantly (p<0.05) associated with HCV infection, independently of age and sex. Multivariate analysis showed that, independently of age, sex, and alcohol intake, genotype 1b infection, with or without coinfection with other genotypes, is the major risk factor associated with the presence of cirrhosis and/or hepatocellular carcinoma. During the three years of follow up, 57 (35%) of the HCV RNA positive subjects had consistently normal alanine aminotransferase and gamma-glutamyltransferase values. Two of the 22 HCV RNA positive cirrhotic patients, all drinking more than 90 g of alcohol a day, developed hepatocellular carcinoma (incidence rate = 3.0% per year). CONCLUSIONS: In the general population of Northern Italy, HCV infection is widespread, but only less than 50% of the anti-HCV positive subjects, particularly those infected with genotype 1b, are associated with a more severe liver disease. Alcohol consumption greater that 30 g a day significantly aggravates the natural course of the disease.
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Hepacivirus/genética , Hepatitis C Crónica/virología , Hígado/virología , Adolescente , Adulto , Distribución por Edad , Anciano , Consumo de Bebidas Alcohólicas , Análisis de Varianza , Animales , Mordeduras y Picaduras , Carcinoma Hepatocelular/virología , Niño , Estudios de Cohortes , Perros , Femenino , Genotipo , Hepatitis C Crónica/diagnóstico por imagen , Hepatitis C Crónica/epidemiología , Humanos , Hígado/diagnóstico por imagen , Cirrosis Hepática/virología , Neoplasias Hepáticas/virología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Prevalencia , ARN Viral/análisis , Factores de Riesgo , Distribución por Sexo , Abuso de Sustancias por Vía Intravenosa , UltrasonografíaRESUMEN
BACKGROUND/AIM: In previous studies we demonstrated that all patients affected by HCV-positive type II mixed cryoglobulinaemia have a monoclonal B-cell population in peripheral blood mononuclear cells, and that a large fraction of HCV-infected patients develop a monoclonal B-cell expansion, even in the absence of dosable serum cryoglobulins. However, the prevalence of Type II mixed cryoglobulinaemia in HCV-infected individuals seems to be high in Italy, whereas it is very low in Japan. This study was performed to investigate whether there are ethnic differences in the prevalence of asymptomatic HCV-associated monoclonal B-cell expansions. METHODS: Forty-four Japanese patients affected by HCV-positive chronic liver disease (two healthy carriers, 31 chronic hepatitis and 11 cirrhosis) were compared with a group of 60 Italian patients (one healthy carrier, 49 chronic hepatitis, and 10 cirrhosis) without dosable levels of cryoglobulins. The monoclonality of peripheral blood mononuclear cells was investigated by RT/PCR analysis of Immunoglobulin gene rearrangements. Liver function tests, rheumatoid factor, cryocrit level, anti-HCV antibodies, HCV-RNA, and HCV genotype were performed according to standard methodology. RESULTS: A B-cell monoclonal population was found in 26% of Italian patients, whereas all Japanese patients were negative. No correlation was found between B-cell monoclonality and severity of liver disease, length or source of the infection, HCV genotype, sex, clinical and biochemical parameters. CONCLUSIONS: This study indicates that a monoclonal B-cell proliferation in peripheral blood mononuclear cells is common in HCV infection, but only in Italy, whereas it is absent in Japan. This explains the very low prevalence of Type II mixed cryoglobulinaemia in HCV-positive Japanese subjects, and suggests that HCV is able to determine a B-cell expansion only in the presence of, presently undetermined, host factors.
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Linfocitos B/citología , Hepatitis C Crónica/genética , Pueblo Asiatico/genética , Portador Sano , Clonación de Organismos , Crioglobulinemia/epidemiología , Femenino , Humanos , Italia/epidemiología , Japón/epidemiología , Cirrosis Hepática/genética , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Prevalencia , Población Blanca/genéticaRESUMEN
BACKGROUND: In a previous paper, we reported on the short-term efficacy of alpha-interferon in the treatment of hepatitis C virus positive mixed cryoglobulinaemia. AIMS: We investigated the long-term effects of therapy in a larger group of patients, and the viral and host factors able to influence the response to treatment. METHODS: In 27 females and 15 males (mean age 54.8 +/- 9.1 years) affected by mixed cryoglobulinaemia, bone marrow biopsy and phenotyping of marrow cells were performed before treatment and at the end of follow-up. A liver biopsy was obtained from patients showing biochemical signs of chronic liver disease. The presence of hepatitis C virus was assessed by detection of serum anti-hepatitis C virus antibodies, and hepatitis C virus-RNA. The treatment schedule was 3 million units of recombinant interferon alpha-2b three times a week for one year. Follow-up lasted for 1 year after the end of treatment. The response was classified as follows: 1) Complete response: Disappearance of the cryocrit (or reduction of more than 50%) and of all clinical manifestations of the disease. 2) Partial response: Disappearance of all clinical signs of the disease, but reduction of cryocrit of less than 50%. 3) Minor response: Reduction of cryocrit of less than 20% associated with the disappearance of one or more (but not all) signs of vasculitis. RESULTS: Anti-hepatitis C virus antibodies were present in 41 (95%) patients, and hepatitis C virus-RNA was detectable in all cases. Before therapy, marrow histology showed a massive monomorphous infiltration by plasmacytoid lymphocytes indicating the presence of low-grade non-Hodgkin lymphoma in 7 cases (16.6%). After therapy, 13 (31%) patients achieved a complete response, 23 patients (55%) a partial response, and 6 patients (14%) a minor response. Seven of the responders and all patients showing partial or minor responses relapsed a few months after withdrawal of therapy. At the end of the follow-up, only 6 patients had obtained complete remission. Bone marrow examination showed that B-lymphocytic monoclonal infiltrate had disappeared in 3 long-term responders. No difference was found between responders and non-responders/relapsers in terms of age, sex, duration of the disease, severity of symptoms, liver function tests, rheumatoid factor or complement levels, while the lack of response was associated with the presence of genotype 1b, liver cirrhosis, and high cryoglobulin level. CONCLUSIONS: Mixed cryoglobulinaemia is associated with a high prevalence of B-cell lymphomas. Alpha-Interferon is an effective agent for the treatment of this disease and seems able to determine regression of the lymphoproliferative disorder. The hepatitis C virus genotype and cryoglobulin level are the most important predictive factors of response to therapy.
Asunto(s)
Antivirales/uso terapéutico , Crioglobulinemia/terapia , Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/inmunología , Hepatitis C/inmunología , Interferón-alfa/uso terapéutico , Biopsia , Médula Ósea/patología , Crioglobulinemia/complicaciones , Crioglobulinemia/inmunología , Femenino , Estudios de Seguimiento , Hepacivirus/genética , Hepatitis C/complicaciones , Hepatitis C/patología , Humanos , Linfoma no Hodgkin/complicaciones , Linfoma no Hodgkin/inmunología , Linfoma no Hodgkin/patología , Masculino , Persona de Mediana Edad , Fenotipo , Reacción en Cadena de la Polimerasa , Valor Predictivo de las Pruebas , ARN Viral/análisis , Linfocitos T/inmunología , Resultado del TratamientoRESUMEN
BACKGROUND/AIM: A striking correlation between mixed cryoglobulinaemia and chronic hepatitis C virus infection has recently been described. Since membrano-proliferative glomerulonephritis is a rare complication of mixed cryoglobulinaemia, this study was undertaken to determine the prevalence of Hepatitis C virus infection in membrano-proliferative glomerulonephritis. PATIENTS: Eighteen patients, selected among a group of 121 affected by mixed cryoglobulinaemia, with renal involvement were included in the present study. A group of 148 patients affected by renal disease of different aetiology and the general population (6,917 people) were used as control groups. METHODS: The presence of anti-hepatitis C virus antibodies was determined by a commercial kit. The hepatitis C virus genotype was determined according to Okamoto. All patients underwent kidney and bone marrow biopsy, while the hepatic biopsy was performed in those showing signs of chronic liver disease. RESULTS: In patients with renal involvement, the kidney biopsy showed the presence of membrano-proliferative glomerulonephritis Type I in all cases. Chronic liver disease was present in eleven patients (61%). All patients were positive for serum hepatitis C virus-RNA. Bone marrow biopsy was normal in five cases, while in the others paratrabecular foci of infiltration by small lymphocytes were present. In six of these, the massive bone marrow infiltration by lymphoplas-macytoid lymphocytes suggested the diagnosis of low grade non-Hodgkin's lymphoma. In the group of patients affected by other chronic renal disease, the prevalence of hepatitis C virus infection (3.1%) was not different from that of the general population (3.2%). CONCLUSIONS: Hepatitis C virus seems to be the aetiologic agent of mixed cryoglobulinaemia and, consequently, of membrano-proliferative glomerulonephritis.