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Biomedical subjects

A Bismuth

Publications and source records attributed to A Bismuth.

At least 19 recordsLinked to original sources
PubMed1992

[Relapse prevention in liver transplant patients treated for liver involvement due to hepatitis B virus].

Controversy surrounds the indication of liver transplantation in patients with hepatitis B virus infection. The major problem is the very high risk of infection of the graft. Some investigators have suggested that the presence of HBsAg is a contraindication to liver transplantation. Between February 1975 and December 1990, 178 HBs positive patients were transplanted at Paul Brousse Hospital in Professor H. Bismuth's Department, 137 for post hepatitis cirrhosis and 41 for fulminant hepatitis. Since April 1984 we have decided long term immunoprophylactic therapy for all patients with HBs infection. But only from August 1987 our supply of purified anti HBs immunoglobulin has been adequate to treat all our patients according to the following protocol: 10.000 IU during the peroperative phase, 10.000 IU immediately after intervention, 10.000 IU every day for the first 6 days, 10.000 IU when the anti HBs levels were under 150 IU/l. One hundred thirty-nine patients were treated by this method. 110 cleared HBs antigen from their sera and their liver were biologically and histologically free of B virus infection. 29 patients showed reappearance of HBs antigen in their sera and nearly all of them developed objective, histologically confirmed, graft lesions. These lesions are those of classical infection: acute hepatitis, active chronic hepatitis and cirrhosis. So 79% of patients were successfully treated with a follow up of 45 months to 6 months. We also studied the prognostic factors under treatment. The study shows: in the case of fulminant hepatitis, 93% success versus 77% in post hepatitis cirrhosis; in the case of Delta superinfection, 94% success versus 66% with pure B infection; in the absence of HBVDNA in the patient's sera before transplantation, 92% success versus 20% in the presence of HBVDNA. For a better understanding of the overall results, the two following parameters have to be considered: some patients relapsed after stopping their treatment, some other patients, despite repositivation of HBs antigen in their sera showed a paradoxal good evolution. These considerations enable us to obtain HBVDNA positive patients: 10% success, HBVDNA negative patients: Fulminant hepatitis: 100% success B Delta post hepatitis cirrhosis: 100% success B post hepatitis cirrhosis: 92% success.

Hepatitis B↗
PubMed1992

Immunoadsorption of anti-HLA antibodies for highly sensitized patients awaiting renal transplantation.

Fifteen end-stage renal disease patients with high titres of panel reactive (PRA) antibodies were treated with immunoadsorption (IA) on sepharose-bound protein A columns in order to remove anti-HLA antibodies and facilitate transplantation. Infectious complications were not observed after IA and transplantation, and the procedure was well tolerated. In spite of the use of adjunctive immunosuppressive treatment with cyclophosphamide and prednisolone, this method produced only variable effects in lowering panel reaction antibodies, and was hampered by high de novo resynthesis of anti-HLA antibodies. Patients whose pre-IA antibody titre was greater than or equal to 1:64 clearly did not benefit from the procedure, but other immunological criteria were not predictive of efficacy. Twelve patients were transplanted on the basis of a negative cross-match with current serum, historical sera being retrospectively tested. Surprisingly, seven patients received a well-matched graft with both pre- and post-IA negative cross-matching. Graft survival was 86% in this group. Conversely, in the group of five transplants which were performed in recipients having a positive historical cross-match with the donor, graft survival was only 40%. One patient died with a functional graft, and two grafts failed due to hyperacute humoral rejection. Humoral rejection in a third patient was successfully treated by a second IA course and administration of polyclonal IgG. We conclude that IA is a safe procedure for managing hyperimmunized transplant candidates. However, its efficacy remains variable, and a better definition of patients who should benefit from IA needs to be found.

Adsorption↗
PubMed1992

Reinfection of liver graft by hepatitis C virus after liver transplantation.

We have investigated hepatitis C virus (HCV) viremia before and after orthotopic liver transplantation (OLT). 38 patients were examined; 16 were anti-HCV positive and 22 anti-HCV negative pre-OLT in a RIBA-2 test (Ortho Diagnostic Systems Inc., Westwood, MA). HCV-RNA was detected using a modified nested polymerase chain reaction in 14/38 and 10/38 patients before and after OLT, respectively. 7 of these 14 subjects who were HCV-RNA positive before OLT were also positive for serum hepatitis B surface antigen. After OLT, six patients became HCV-RNA positive, likely as a result of transfusions, while four developed a probable recurrence of HCV infection. Infection of the liver graft by the same strain of HCV was indeed demonstrated by sequence analysis of a hypervariable domain (in the envelope region) in two cases. This establishes the possibility of HCV recurrence and shows the usefulness of polymerase chain reaction as the only assay currently capable of identifying HCV infection after OLT.

Base Sequence↗
PubMed1992

Anti-HLA antibodies depletion on protein A-sepharose columns in hyperimmunized patients awaiting renal transplantation.

To reduce anti-HLA immunization, 15 patients waiting for a renal graft received the following treatment: 5 to 7 immunoadsorption sessions on protein A-Sepharose columns, immunosuppressive drugs (corticosteroids 1 mg/kg (bw/day+cyclophosphamide 2 mg/kg bw/day) and iv polyclonal immunoglobulins. Before this treatment, panel-reactive antibodies ranged from 65 to 100% and antibody titers varied from 1/8 to 1/128. In all patients, antibody, titers were decreased. However, antibody resynthesis was incompletely blocked by this protocol. Eight out of 12 grafted patients had a functional kidney transplant 3 months to 3 years post-grafting. There early kidney failures occurred in the subgroup of 5 patients who had had historical positive cross matches prior to treatment. This treatment did not seem to increase the frequency of infectious complications before or after grafting.

Adult↗
PubMed1992

How to deal with the hyperimmunized potential recipients.

End-stage renal disease (ESRD) patients with high levels of anti-HLA panel reactive antibodies (PRA) represent an increasing group in which sensitization, induced by pregnancies, previous transplants, and blood transfusions, considerably delay the opportunity to receive a graft. Currently, more than 50% of the 4700 patients awaiting transplantation in France are sensitized, of which 33% are defined as hyperimmunized (PRA greater than = 80%), and only 9.5% of the total number of transplants have been done in highly sensitized recipients. The magnitude of this problem, similar in Europe and North America, explains why more active strategies for managing hyperimmunized patients have been introduced during the past decade. Clearly, the simplest is finding of a well-matched organ that does not carry the HLA antigens against which the recipient has generated antibody, but that is limited by the number of shared grafts. The second is the development of a new cross-matching technique prior to transplantation. Attempts at immunoregulation of secreting B cell clones have been carried out using either hypertransfusions or injection of polyclonal Ig. Finally, removal and prevention of the resynthesis of HLA antibodies is a most attractive approach using immunoadsorption (IA) system with sepharose-bound protein-A columns. In our unit, fifteen ESRD patients with high levels of PRA were treated with IA. Infectious complications were not observed after IA and transplantation, and the procedure was well tolerated. In spite of the use of adjunctive immunosuppressive treatment with cyclophosphamide and prednisolone, this method produced only variable effects in lowering PRA levels, and was hampered by high de novo resynthesis of anti-HLA antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1991

Passive immunoprophylaxis after liver transplantation in HBsAg-positive patients.

110 HBsAg-positive patients underwent orthotopic liver transplantation and received long-term anti-hepatitis B virus (HBV) passive immunoprophylaxis with anti-HBs immunoglobulin. During a mean follow-up period of 20 months, all patients became HBsAg negative after transplantation but circulating HBsAg reappeared in 25 (22.7%). Overall 1-year survival was 83.6% and overall 2 year actuarial recurrence of HBsAg was 29% (59% after posthepatitis B cirrhosis, 13% after posthepatitis B-delta cirrhosis, and 0% after fulminant hepatitis B). Patients with HBV cirrhosis who were HBV-DNA positive had a much greater risk of HBsAg recurrence than patients who were HBV-DNA negative (96% vs 29% at 2 years). Reappearance of HBsAg was associated with evidence of HBV replication and abnormal histological findings in the graft. Long-term passive anti-HBV immunoprophylaxis significantly reduced HBV reinfection and improved survival in patients without evidence of active HBV replication before orthotopic liver transplantation.

Adolescent↗
PubMed1991

[Safety of donors, quality of products, how much to reduce the quantity of citrate].

We examined 1,053 blood samples from 48 donors, for the effect of gradual reduction of citrate. We observed that: 1--Platelet count does not show any significant variation between 1/8 to 1/18 ratio. 2--In 13.3% of the cases, platelet clumping starts at 1/18 ratio. 3--There was no significant variation of the thrombin plasma level between 1/8 to 1/16 ratio (by measuring thrombin/ATIII complex). Our results show clearly that we can reduce the citrate ratio to 1/14 without expecting any adverse effect. Therefore we designated 1/14 as the security ratio. Parallel to this we also found that the average level +/- SD of ionized calcium is 100 +/- 10 muMol at 1/14 ratio.

Adult↗
PubMed1991

[Liver transplantation and the major histocompatibility complex].

We have carried out a retrospective study over 308 liver transplant patients (31 of them have had a retransplantation) in Professor Bismuth's Department at Paul Brousse Hospital. The purpose of the study was a search for the possible effect of donor/recipient major histocompatibility complex on the evolution of the transplantation. We chose to study four parameters: early acute rejection; chronic rejection; retransplantation cases and death frequency; graft survival. We observed the following: for HLA A locus: in cases of total or partial compatibility there are more moderate early acute rejections than in the case of incompatibility (p less than 0.02); for HLA B locus: in the case of total compatibility there are more chronic rejections than in cases of partial or total incompatibility (p less than 0.03); for joint A and B locus: the results are similar to those of A locus (p less than 0.03); for HLA class I: we observed no effect either on graft survival or on retransplantation cases or on death frequency; for HLA DR: we did not find any effect on the studied parameters. Considering the low statistical significance of these results and in order to confirm our analysis, we have started a prospective study in collaboration with two other European Transplantation Centers.

Graft Rejection↗
PubMed1990

Serum hepatitis delta virus RNA in patients with delta hepatitis and in liver graft recipients.

We have investigated the usefulness of serum hepatitis delta virus (HDV) RNA detection using a slot hybridization analysis of serum samples from ten patients with acute hepatitis and delta markers (group I), from 28 patients with chronic delta hepatitis (group II) and from seven liver graft recipients with hepatitis B virus (HBV) and HDV related cirrhosis or fulminant hepatitis (group III). The slot-blots were hybridized with both HDV-complementary DNA and single-stranded RNA probes. With the single-stranded RNA probe, HDV RNA was detected in the first serum sample available in 9/10 of the patients with acute hepatitis (group I). In addition, HDV RNA was detected in 8/9 and 7/8 of the samples obtained within and after 1 month of the onset of hepatitis. Five of the ten patients scored positive for HDV RNA and negative for hepatitis delta antigen (HDAg) while one was negative for HDV RNA and positive for HDAg. The same RNA probe enabled the detection of serum HDV RNA in 21/28 chronic hepatitis patients (liver HDAg and/or IgM anti-HD positive) (group II). Among the liver graft recipients (group III), 7/7 had a recurrent delta infection. Serum HDAg, liver HDAg and anti-HD IgM were identified in 3/7, 6/7 and 5/7 of the patients, respectively. HDV RNA was detected in the seven patients with either persistent (4/7) or transient (3/7) positivity. In addition, HBsAg and HBV RNA were persistently shown in 4/7 patients with continuous HDV replication. In the remaining three patients, HDV RNA was detectable despite the absence of HBsAg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Persistent hepatitis B virus infection of mononuclear blood cells without concomitant liver infection. The liver transplantation model.

We have investigated the recurrence of Hepatitis B virus (HBV) in 30 patients treated by orthotopic liver transplantation and given high doses of anti-HBs immunoglobulin. The polymerase chain reaction (PCR) assay showed no evidence of HBV DNA sequences in the liver of 23/24 patients who remained serum HBsAg-negative during a mean follow-up of 13 months (2-24 months) after OLT. However, the liver scored positive in all the 6 individuals in whom HBsAG reappeared. The PCR assay identified HBV DNA sequences in the peripheral blood mononuclear cells of 7 of 11 subjects who were serum HBsAG-negative and liver HBV DNA-negative by PCR. Therefore, this application of the sensitive PCR assay demonstrates persistent infection of PBMC in the absence of liver HBV--thus OLT provides a model for studying the interaction between HBV, PBMC, and the liver.

DNA, Viral↗