PubMed Health⌕ Search

Biomedical subjects

J J Lefrère

Publications and source records attributed to J J Lefrère.

At least 19 recordsLinked to original sources
PubMed2005

Changing of hepatitis C virus genotype patterns in France at the beginning of the third millenium: The GEMHEP GenoCII Study.

This cross-sectional study aimed to investigate, during a short period between 2000 and 2001, in a large population of patients with chronic hepatitis C, the epidemiological characteristics of hepatitis C virus (HCV) genotypes in France. Data from 26 referral centres, corresponding to 1769 patients with chronic hepatitis C were collected consecutively during a 6-month period. HCV genotyping in the 5'-non-coding region (NCR) was performed in each center using the line probe assay (LiPA, in 63% of cases), sequencing (25%) or primer-specific polymerase chain reaction (PCR) (12%). HCV genotypes 1a, 1b, 2, 3, 4, 5, non-subtyped 1 and mixed infection were found in 18, 27, 9, 21, 9, 3, 11 and 1% of our population, respectively. HCV genotype distribution was associated with gender, age, source and duration of infection, alanine aminotransferase (ALT) levels, cirrhosis, alcohol consumption, hepatitis B virus (HBV) and human immunodeficiency virus (HIV) coinfection. In multivariate analysis, only the source of infection was the independent factor significantly associated with genotype (P = 0.0001). In conclusion, this study shows a changing pattern of HCV genotypes in France, with i.v. drug abuse as the major risk factor, an increase of genotype 4, and to a lesser extent 1a and 5, and a decrease of genotypes 1b and 2. The modification of the HCV genotype pattern in France in the next 10 years may require new therapeutic strategies, and further survey studies.

Adult↗
PubMed2001

Seroprevalence of human herpes virus 8 antibody in populations at high or low risk of transfusion, graft, or sexual transmission of viruses.

BACKGROUND: The routes of transmission of human herpes virus 8 (HHV-8) remain unclear. In particular, HHV-8 transmission by blood components and organ transplantation is still debated and raises public health issues. The objective of this study was to determine the prevalence of anti-HHV-8 in selected populations of persons or patients with or without risk factors for the transmission of viral infections, in order to determine the routes of HHV-8 transmission. STUDY DESIGN AND METHODS: A total of 1431 persons or patients at low or high risk of sexually, blood-, or graft-transmitted viral infections were tested by means of a standardized immunofluorescence serologic assay detecting anti-HHV-8. RESULTS: The persons or patients could be classified into three distinct groups according to anti-HHV-8 prevalence: a low prevalence group (0.0% to 5.0%), including healthy blood donors, healthy pregnant women, multiply transfused patients with thalassemia major, and IV drug users; an intermediate prevalence group (5.0% to 20.0%), including organ donors, kidney transplant recipients, and multiply transfused patients with sickle cell disease; a high prevalence group (>20.0%), including HIV-negative persons at high risk of sexually-transmitted viral infections, and HIV-infected homosexual men and heterosexuals. CONCLUSION: The sexual route appears to be the main route of HHV-8 transmission; bloodborne transmission of HHV-8, if it exists, is rare. In contrast, organ transplantation recipients might be exposed to HHV-8 transmission by the transplanted organ, which raises the issue of systematic screening of organ donors.

Adult↗
PubMed2000

[Human T-lymphotropic virus type I (HTLV-I): risk of transmission with transfusion].

PATHOGENIC ROLE: The human T-lymphotropic virus type I (HTLV-I), the first human retrovirus discovered, is the etiologic agent of adult T-cell leukemia/lymphoma (ATL) and of HTLV-I associated myelopathy or tropical spastic paraparesis (HAM/TSP) and has a widespread but uneven worldwide distribution. HTLV-I has a high seroprevalence in Southern Japan, the Caribbean basin and Sub-Sahara Africa. Blood transfusion, intravenous drug use, breast feeding and sexual contacts are major routes of contamination. IMPLICATIONS FOR BLOOD TRANSFUSION: The screening of blood donors for antibody to HTLV-I became systematic in 1989 in French West Indies and in 1991 in Continental France. This review deals with the transfusional implications of the HTLV-I, which belongs to the group of the blood-borne viruses: the prevalence of transfusion-linked HTLV-I infection before the implementation of the specific preventive measures, the parameters influencing the risk of transfusional contamination (the type of blood products, the age of the blood product with regards to its collection date, the proviral load of the blood donor), the prognosis of HTLV-I infection in patients contaminated by transfusion, the prophylactic strategies of transfusion contamination and the residual risk of infection through HTLV-I-infected risk blood products.

Adult↗
PubMed2000

Natural history of the TT virus infection through follow-up of TTV DNA-positive multiple-transfused patients.

Little is known about the natural history and the pathogenicity of the TT virus (TTV). We present our findings of a cross-sectional study based on the TTV DNA screening of 173 multiple-transfused patients and a longitudinal study based on the follow-up of TTV DNA-positive patients. Overall, 48 patients (27.7%) tested positive for TTV DNA. The influence of the number of blood donor exposures on the prevalence of blood-borne viral infection indicates that TTV, hepatitis C virus (HCV), and an RNA virus known as GB virus C/hepatitis G virus (GBV-C/HGV) share a parenteral transmission, but that TTV, in contrast to the 2 other viruses, is also transmitted by at least another efficient means. The patients having a well-defined date of TTV infection were positive for TTV DNA during a mean period of 3.1 years. A chronic infection was observed in 31 cases (86%). TTV carriage appeared clinically benign in all patients. No clinical evidence of a disease potentially linked to the TTV infection was observed in patients with TTV DNA carriage over several years. The majority of TTV carriers had no biochemical evidence of liver disease. The prevalence of elevated serum alanine aminotransferase (ALT) level was higher in the TTV DNA-positive group, even in the absence of HCV infection, but the observed peaks of ALT level were most often transient and very mild. The prevalence of TTV DNA observed in blood recipients is consistent with that of TTV infection observed in blood donors. TTV infection frequently tends to persist. (Blood. 2000;95:347-351)

Adolescent↗
PubMed2000

Lessons from a multicentre study of the detectability of viral genomes based on a two-round quality control of GB virus C (GBV-C)/hepatitis G virus (HGV) polymerase chain reaction assay.

The aim of this study was to determine whether multicentre quality controls for the detectability of viral genomes could contribute to the improvement of diagnostic performance in the participating laboratories. The study was carried out during two successive rounds, during which 18 laboratories specialized in nucleic acid testing analyzed, through a polymerase chain reaction (PCR) assay, a common panel of GB virus C (GBV-C)/hepatitis G virus (HGV) RNA-positive and -negative samples. During the first round, the laboratories used either an 'in-house' PCR procedure or a partly standardized commercial test. After decoding the results of the first round, the procedures of the participating laboratories were compared in order to establish a consensus procedure deduced from those of the laboratories which provided the best results. During the second round, each participating laboratory could use the resulting consensus procedure, or its own procedure, or both. The results of this quality control study indicated that, whatever method used, even specialized and trained laboratories may give false-negative or false-positive results. The commercial assay did not guarantee a systematic high quality level of results. The striking heterogeneity of results observed among laboratories using the same commercial assay confirm that molecular biology methods need skilled technicians. The results of this quality control study suggest that full standardization of viral genome detection, including all steps of the procedure, is necessary and that the laboratories performing PCR should participate in repeated quality control studies, whatever technique is being used.

Flaviviridae↗
PubMed2000

High rate of GB virus type C/HGV transmission from mother to infant: possible implications for the prevalence of infection in blood donors.

BACKGROUND: Because GB virus type C(GBV-C)/HGV (GBV-C/HGV) is blood-borne and sexually transmitted, persons at risk of infection with such viruses have a high prevalence of GBV-C/HGV markers. However, adults with no apparent risk factors, such as blood donors, frequently are positive for GBV-C/HGV markers. Mother-to-infant transmission could explain this high prevalence, but it has been studied only through small series of GBV-C/HGV-infected mothers co-infected with HCV or HIV. STUDY DESIGN AND METHODS: To determine the rate of mother-to-infant transmission of GBV-C/HGV RNA in women who are HCV- or HIV-negative, a prospective study was performed in a cohort of 288 mothers screened for viral RNA and in the infants born to GBV-C/HGV-infected mothers. RESULTS: Thirteen mothers (4.5%) were found positive for GBV-C/HGV RNA. Of the infants in whom at least one blood sample was collected between the third and the ninth months of life, 89 percent were positive for viral RNA. The majority of these newborns were negative for GBV-C/HGV RNA at birth and positive after the third month. The viral RNA titers of infants born to GBV-C/HGV-infected mothers appeared as elevated as those of their mothers. All the GBV-C/HGV-infected infants remained positive for viral RNA during the entire study period. No clinical events possibly linked to a primary GBV-C/HGV infection were reported in infants. Serum ALT level and blood count remained within normal values throughout the follow-up of all GBV-C/HGV-infected infants. CONCLUSION: The frequency of mother-to-infant GBV-C/HGV transmission is elevated and could explain the high prevalence of GBV-C/HGV markers (viral RNA and E2 antibody) in adults at low risk for blood-borne or sexually transmitted viruses, such as blood donors.

Adult↗
PubMed1999

GBV-C/hepatitis G virus (HGV) RNA load in immunodeficient individuals and in immunocompetent individuals.

The aim of this study was to establish the mean plasma GBV-C/hepatitis G virus (HGV) RNA load in groups of GBV-C/HGV-infected individuals with varied immune status and to determine the most frequent patterns of evolution of the plasma GBV-C/HGV RNA load over time during the natural history of infection. The mean plasma GBV-C/HGV RNA load observed was, from the lowest to the highest: 5.21 log in immunodepressed multiply-transfused patients, 6.45 log in HIV-positive individuals, 6.66 log in immunocompetent multiply-transfused patients, and 6.71 log in blood donors. The difference was significant between the four groups (P < 0.0001). The most frequent pattern of evolution of the plasma GBV-C/HGV RNA load was as follows: after the primary GBV-C/HGV infection, the viral load was elevated from the onset; then, a high, persistent and relatively steady viral RNA level was the rule; and when it occurred, the loss of viremia was not preceded by a decrease before recovery from GBV-C/HGV infection.

Adolescent↗
PubMed1999

Screening for HBV, HCV and HIV genomes in blood donations: shortcomings of pooling revealed by a multicentre study simulating real-time testing.

This study was undertaken in order to determine whether screening of viremic blood donations by testing of pooled donor samples could constitute a technically feasible transfusional safety measure. A pilot study of real-time simulation, on a day-to-day basis, of screening of three viral genomes (hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV)) was conducted by five French Blood Centers on plasma samples collected from blood donors and studied within undiluted samples and within sample pools of various sizes. This study was carried out within time conditions compatible with the release of platelets. For the detection of HCV and HIV genomes, the five laboratories achieved a sensitivity that decreased with the size of the sample pool. Four were successful in detecting all undiluted samples. In the 1/10 diluted samples, four failed to detect one HIV or HCV sample. In the 1/100 diluted samples, all laboratories failed to detect one or more HIV or HCV samples. For HBV genome, no participating laboratories detected all of the samples of the panel, even undiluted samples, and the sample pooling considerably affected sensitivity. The improvement and standardization of assays needs to be attained, and training of laboratories appears to be a step crucial for routine screening of viral genomes in blood donations.

Blood↗
PubMed1999

Prevalence of GB virus type C/hepatitis G virus RNA and of anti-E2 in individuals at high or low risk for blood-borne or sexually transmitted viruses: evidence of sexual and parenteral transmission.

BACKGROUND: The first epidemiologic evidence of GB virus type C (GBV-C)/hepatitis G virus (HGV) infection showed a high prevalence of asymptomatic carriers in blood donors and in populations at risk for blood-borne viruses. However, by using only viral RNA polymerase chain reaction, those studies underestimated the true spread of GBV-C/HGV infection. The combined detection of GBV-C/HGV RNA and of anti-E2 (which reflects recovery from infection) is necessary to define accurately the prevalence of GBV-C/HGV. STUDY DESIGN AND METHODS: The presence of both anti-E2 and GBV-C/HGV RNA was searched for in 1438 serum samples collected from various groups of individuals at low or high risk for blood-borne or sexually transmitted viruses (blood donors, organ donors, unselected pregnant women, immunocompetent or immunodepressed multiply transfused patients, HIV-positive or HIV-negative homosexual men, intravenous drug addicts). RESULTS: The presence of GBV-C/HGV RNA and/or anti-E2 (exposure to GBV-C/HGV) was frequent in populations at risk for blood-borne or sexually transmitted viruses. GBV-C/HGV appeared also to be sexually transmitted, with transmission from male to female more efficient than vice versa. A particularly elevated level of exposure to GBV-C/HGV was observed in homosexual men. In immunocompetent individuals, the prevalence of anti-E2 was about twice that of GBV-C/HGV RNA, which suggests the frequency of recovery from GBV-C/HGV infection. Most of the GBV-C/HGV RNA-positive individuals had no biochemical evidence of liver damage. CONCLUSIONS: GBV-C/HGV is frequent in populations at risk for blood-borne or sexually transmitted viruses. GBV-C/HGV is not a hepatitis virus, and it seems appropriate to rename it.

Alanine Transaminase↗
PubMed1999

Carriage of GB virus C/hepatitis G virus RNA is associated with a slower immunologic, virologic, and clinical progression of human immunodeficiency virus disease in coinfected persons.

The prevalence of GB virus C (GBV-C) infection is high in human immunodeficiency virus (HIV)-infected persons. However, the long-term consequences of coinfection are unknown. HIV-positive persons with a well-defined duration of infection were screened on the basis of their GBV-C/hepatitis G virus (HGV) RNA status and studied. GBV-C/HGV viremia was observed in 23, who carried the virus over a mean of 7.7 years. All parameters (survival, CDC stage B/C, HIV RNA load, CD4 T cell count) showed significant differences in terms of the cumulative progression rate between persons positive and negative for GBV-C/HGV RNA. When GBV-C/HGV RNA-positive and -unexposed subjects were matched by age, sex, baseline HIV RNA load, and baseline CD4 T cell count, HIV disease progression appeared worse in GBV-C/HGV RNA-negative subjects. The carriage of GBV-C/HGV RNA is associated with a slower progression of HIV disease in coinfected persons.

Adult↗
PubMed1999

Plasma human immunodeficiency virus RNA below 40 Copies/mL is rare in untreated persons even in the first years of infection.

To clarify the frequency and prognostic significance of a plasma human immunodeficiency virus (HIV) RNA load below the detection threshold during the natural history of infection, an ultrasensitive assay was used to identify persons with low virus loads in a cohort of 111 untreated subjects with a known date of seroconversion. Six persons had HIV RNA loads <40 viral copies (VC)/mL during the first years of HIV infection. The probability of meeting the criteria for long-term nonprogression was higher in these subjects (P=.043). However, a virus load <40 VC/mL was rare during the natural history of infection, even during the first years of symptomless HIV carriage. Such data confirm the general trend of disease progression in the entire population of HIV carriers.

Adult↗
PubMed1998

[Molecular biology and transfusional viral safety].

In this review we present four fields to which viral molecular biology has contributed: the discovery of blood-borne viruses and the knowledge of the natural history of infection by these viruses; the validation of the results of virological assays used in the biological screening of blood donations; the contribution of molecular biology in inquiries into viral transfusional contamination; the interest of molecular biology in viral transfusional epidemiology. We subsequently deal with the parameters of the discussion on the impact and the feasibility of a systematic screening of several viral genomes in blood donations.

Blood Donors↗
PubMed1998

Screening blood donations for viral genomes: multicenter study of real-time simulation using pooled samples on the model of hepatitis C virus RNA detection.

BACKGROUND: The systematic screening for several blood-borne viral genomes in blood donations is a complementary safety measure planned or discussed by the national authorities of several countries. STUDY DESIGN AND METHODS: To appreciate the feasibility of such screening using pooled samples, a multicenter study of real-time simulation has been performed on the model of hepatitis C virus (HCV) infection. Four blood transfusion center laboratories and two research and diagnosis laboratories simultaneously screened, by several HCV RNA polymerase chain reaction assays, a panel of plasma sample pools of different sizes (500, 100, and 10 samples), collected from HCV-infected or HCV-uninfected blood donors. One viremic plasma was introduced in each pool. HCV RNA was detected by in-house polymerase chain reaction procedures or by standardized manual or semi-automated polymerase chain reaction assays. RESULTS: The results indicate the feasibility of sample pooling, which renders the screening for viral genomes by molecular biology techniques applicable in the short term and the importance of the experience of laboratory personnel in the use of molecular biology tools. CONCLUSION: The improvement of standardized assays needs to be continued, and training of laboratory staff members appears to be a crucial step before systematic screening of blood donations for viral genomes by molecular biology techniques can occur.

Blood Donors↗
PubMed1998

The risk of disease progression is determined during the first year of human immunodeficiency virus type 1 infection.

A cohort of 103 human immunodeficiency virus type 1 (HIV-1)-infected persons with well-defined dates of seroconversion were studied to determine whether baseline plasma HIV RNA loads 6-12 months after seroconversion have prognostic value. Baseline plasma virus loads had predictive value for the disease-free survival rate and for the survival rate. The level of baseline HIV RNA also had a strong negative predictive value for the CD4+ T cell count during the fifth year of infection: A baseline load >5 log was predictive of a CD4+ T cell count <500/mm3 5 years after infection. Baseline HIV RNA load was a CD4+ T cell-independent predictor of progression to death. The major finding was that the disease outcome for HIV-1-infected persons is already determined during the first year of infection.

Adult↗
PubMed1997

Natural history of GBV-C/hepatitis G virus infection through the follow-up of GBV-C/hepatitis G virus-infected blood donors and recipients studied by RNA polymerase chain reaction and anti-E2 serology.

The aims of this study were to determine the outcome and the natural history of GBV-C/hepatitis G virus (HGV) infection and to establish the frequency of acute or persistent infections in multiply-transfused individuals and blood donors. We used a GBV-C/HGV RNA polymerase chain reaction (PCR) and an assay evidencing antibodies to the envelop protein E2, which is considered a marker for virus clearance. Among 16 PCR-positive recipients, 11 were still positive for GBV-C/HGV RNA at the end of the study period; six of the 16 recipients were GBV-C/HGV infected during the study period and thus had a well-defined date of infection. The 16 patients were shown to carry GBV-C/HGV RNA over a mean period of 4.4 years, for a mean observational period (defined as the follow-up period since the first sample positive for GBV-C/HGV RNA) of 5.3 years. Within the limits of the study period, the patients with a well-defined date of infection were positive for GBV-C/HGV RNA during a mean period of 4.7 years. If defined by the presence of GBV-C/HGV RNA for at least 6 months, the persistent infection rate was 100% in this recipient cohort. Serum anti-E2 antibody was evidenced at least once in five (31.2%) recipients and, except in one case, became detectable after the loss of GBV-C/HGV RNA. Among the 11 blood donors, all were still positive for GBV-C/HGV RNA after a mean follow-up period of 7.7 months. The persistent infection rate was 100% in this donor cohort. Once acquired, the infection to GBV-C/HGV generally tends to persist in immunocompetent patients.

Adenovirus E2 Proteins↗
PubMed1997

Even individuals considered as long-term nonprogressors show biological signs of progression after 10 years of human immunodeficiency virus infection.

Despite a decade of human immunodeficiency virus (HIV) seropositivity, a few individuals termed as long-term nonprogressors (LTNPs) maintain a stable CD4+ T-cell count for a period of time. The aim of this study was to establish, through the sequential determination of all known predictors of HIV disease, the proportion of such patients having stringent criteria of true long-term nonprogression. Among 249 individuals who were HIV-infected and prospectively followed up over a 10-year period (1985 to 1995), 12 having a CD4+ T-cell count greater than 500/microL (LTNP I group) and 9 having a CD4+ T-cell count less than 500 but stable over time (LTNP II group) after at least 10 years of infection without intervention of antiviral therapy, were studied over the entire follow-up period. The plasma HIV RNA copy number and the serum concentrations of p24 antigen, each anti-HIV antibody, neopterin, beta-2-microglobulin, Immunoglobulin (Ig) G and IgA were determined every 18 months over the study period. Cellular and plasma viremias were cross-sectionaly assayed in all 21 patients. Only two patients had strictly no marker of progression over the follow-up period. They were the only ones who had, over the 10-year period, a viral copy number too low to be detected. The other patients had a viral copy number higher than 400/mL at at least one visit and increasing over the follow-up period, and they evidenced one or more markers of virological or immunological deterioration. Cellular viremia was positive in all patients but two, while plasma viremia was negative in all but one. The population of individuals termed as LTNPs is not virologically and immunologically homogeneous. The majority present biological signs of HIV disease progression. A new pattern of true LTNP can be drawn through stringent criteria based on the whole known predictors. This pattern appears to be rare in HIV-positive population.

Adult↗