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Biomedical subjects

R de Biasi

Publications and source records attributed to R de Biasi.

13 recordsLinked to original sources
PubMed1999

Successful immune tolerance treatment with monoclonal or recombinant factor VIII concentrates in high responding inhibitor patients.

Very high purity factor VIII (FVIII) concentrates (plasma-derived or produced by recombinant-DNA technology) were used to achieve immune tolerance in five patients with high-responding inhibitors to FVIII. The mean time required for inhibitor disappearance was 5 months. Four out of five patients showed normalisation of the half-life of infused FVIII after 8-18 months of treatment with 100 IU FVIII/kg body weight administered once daily. Highly purified FVIII products thus appear to be suitable for achieving immune tolerance without negative effects on endogenous von Willebrand factor levels and activity.

Adolescent↗
PubMed1994

Hemofil-M study.

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CD4-CD8 Ratio↗
PubMed1994

Patterns of immunogenicity of an inactivated hepatitis A vaccine in anti-HIV positive and negative hemophilic patients.

Hepatitis A vaccination has been recommended to patients with hemophilia since they are exposed to potentially infectious clotting factor concentrates. Aim of this study was to assess the immunogenicity of vaccination in hemophiliacs, infected or not with the human immunodeficiency virus (HIV). A formalin-inactivated hepatitis A vaccine was injected subcutaneously to 113 susceptible adults and children and repeated after 1 and 6 months. 47 vaccinees were anti-HIV positive (28 asymptomatic, 15 with CD4 cell counts of less than 200/microliter and 4 with symptomatic disease). The first dose of vaccine induced seroconversion, with antibody titers of at least 20 mIU/ml, in 89% of the 66 anti-HIV negative patients, 100% of them responding after the second injection. In anti-HIV positive hemophiliacs seroconversion rates and antibody titers were significantly lower than in non-infected patients. After 12 months, only 76% of anti-HIV positive vaccinees and 40% of those with signs of HIV disease progression maintained the antibody, whereas all anti-HIV negative patients had titers of 20 mIU/ml or more. Our results indicate that there is an association between defective response to hepatitis A vaccine and stage of progression of HIV disease.

Adolescent↗
PubMed1994

Incidence of factor VIII inhibitor development in hemophilia A patients treated with less pure plasma derived concentrates.

Very-high-purity Factor VIII concentrates produced by monoclonal or recombinant technology have been postulated to be more antigenic resulting in an increased risk of inhibitor development in hemophilia A patients. However, previous reports, mainly based on prevalence figures, may have underestimated the "true" risk of this complication in patients treated with less pure Factor VIII concentrates. The present study, started in 1975, has been designed to calculate the risk of inhibitor development in patients with severe or moderate hemophilia A, followed since their first exposure to intermediate or high-purity Factor VIII concentrates, produced by conventional technologies. Sixty-four hemophiliacs fulfilled the enrollment criteria. Inhibitors developed in 20.3% (13/64) of all patients and in 23% (11/48) of those with severe Factor VIII deficiency. Eleven patients manifested a strong anamnestic response after exposure to Factor VIII (high responders) and 2 had low inhibitor concentrations despite repeated Factor VIII infusions (low responders). The incidence of inhibitor development was 24.6 per 1000 patient-years of observation. The cumulative risk of inhibitor formation was 19.9% at age of 6 years, and 20.3% at 5 years after the first exposure. The risk was 19.3% at 70 days of exposure to Factor VIII concentrates, and 17.2% after a total of 50,000 units of Factor VIII given. Further studies are needed to confirm the above risk of acquiring an inhibitor, which indicates an under-estimation by previous studies. In addition, more data is needed to demonstrate whether very-high-purity Factor VIII concentrates may be more antigenic than conventional preparations.

Adolescent↗
PubMed1992

Immune status of asymptomatic HIV-infected hemophiliacs: randomized, prospective, two-year comparison of treatment with a high-purity or an intermediate-purity factor VIII concentrate.

It has been postulated that high-purity factor VIII (FVIII) concentrates, since they contain less alloantigenic proteins than intermediate-purity concentrates, might cause lesser deterioration of the immune systems of hemophilic patients infected with the human immunodeficiency virus (HIV). To evaluate this hypothesis, we have prospectively compared T-lymphocytes subsets and delayed hypersensitivity reactions to skin tests in 17 asymptomatic HIV-positive hemophiliacs randomly assigned to continue treatment with an intermediate-purity concentrate with those of 16 hemophiliacs changed to a high-purity concentrate. For both groups, during the 24-month follow-up period CD4 cell counts showed similar rates of fall from baseline values. There was also no difference in the number of patients anergic to skin tests. Three patients treated with the intermediate purity concentrate and one treated with the high-purity concentrate developed symptoms of HIV infection. On the whole, no striking benefit is conferred to the immune status of asymptomatic HIV-positive hemophiliacs by using this high-purity concentrate for 2 years.

Adolescent↗
PubMed1992

The impact of clotting factor concentrates on the immune system in individuals with hemophilia.

All reported studies to date, whether comparative or not, have shown a tendency toward a slower decrease in CD4+ numbers in patients receiving very high-purity agents with the rapidity in fall-off being affected by level of CD4+ numbers (low CD4+ numbers decreasing more rapidly), age (older persons showing more rapid CD4+ cell fall-off), and anti-HIV therapy. Clearly, these observations need to be extended in numbers, and the high-purity agents should also be similarly compared with the very high-purity therapies.

Antigens↗
PubMed1991

The impact of a very high purity factor VIII concentrate on the immune system of human immunodeficiency virus-infected hemophiliacs: a randomized, prospective, two-year comparison with an intermediate purity concentrate.

Pathophysiologic considerations as well as non-comparative clinical results suggest that very high purity concentrates may slow immunologic deterioration in human immunodeficiency virus (HIV)-infected hemophiliacs. In an attempt to evaluate this hypothesis, we prospectively compared CD4 cell counts, skin testing responses, and changes of the clinical status in 20 asymptomatic HIV-positive hemophiliacs, randomly assigned to continue the treatment with an intermediate purity concentrate or to receive a very high purity product, purified by immunoaffinity chromatography with monoclonal antibodies. In the group switched to the very high purity concentrate there was no significant change of the CD4 cell counts over the 96-week follow-up period, whereas in the group continued on the intermediate purity concentrate, a highly significant decline was detected (P less than .013). Furthermore, in the very high purity group, four of six anergic patients at entry acquired reactivity to skin testing. The results of this study clearly support the use of very high purity concentrates for the replacement therapy of HIV-infected hemophiliacs.

Adult↗
PubMed1991

AIDS and hemophilia.

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Acquired Immunodeficiency Syndrome↗
PubMed1989

Long-term immunogenicity of a plasma-derived hepatitis B vaccine in HIV seropositive and HIV seronegative hemophiliacs.

Short-term studies indicate that hepatitis B vaccines are safe and satisfactorily immunogenic in hemophiliacs. The duration of immunity in these immunocompromised patients, however, is not known. To determine this, we studied 78 hemophiliacs prospectively 2, 3, and 4 years after the initial vaccination with a plasma-derived vaccine given as three monthly injections followed by a fourth booster injection at month 14. The duration of immunity clearly depended on whether the patients were infected with the human immunodeficiency virus (HIV). In HIV seronegative hemophiliacs (n = 67), there was a progressive decline in titers of antibody to the hepatitis B surface antigen (anti-HBs), but antibody was still detectable 4 years later in all of them. From the curves of decline of antibody titers, it appears that there is no need to revaccinate patients for at least 5 to 6 years. The HIV seropositive hemophiliacs (n = 11) not only started from much lower anti-HBs titers, but 5 of 11 lost anti-HBs. None of the 45 patients treated with concentrates during the postvaccination period developed serologic signs of hepatitis B, even though 6 of them had come into contact with live or inactivated hepatitis B virus as shown by the occurrence of spontaneous anamnestic antibody responses. This vaccine and schedule of vaccination afford a prolonged duration of immunity in HIV seronegative hemophiliacs, but HIV seropositive hemophiliacs have a risk of losing immunity early.

Adolescent↗
PubMed1985

Liver disease in hemophiliacs: etiological and biochemical data on 159 cases from our geographical area.

A total of 159 hemophiliacs (149 treated) from our geographical area were screened in 1983 for serological evidence of HBV infection and biochemical evidence of liver disease. All were asymptomatic. HBsAg was detected in 16 cases (10%); anti-HBs and anti-HBc in 106 (67%); 19 (12%) subjects were susceptible to HBV. The HBV infection rate evaluated in 70 patients followed-up from 1980 to 1983 was 28% per year. The cumulative risk of HBV infection as well as the rate of seroconversion to HBV increased with increasing age and with increasing frequency of treatment given during the last 12 months. Anti-delta was detected in the serum of 5 (28%) out of 13 HBsAg-positive cases. Follow-up data showed that in 61% of subjects with liver dysfunction, hepatic damage could not be accounted for by HBV infection. AST and/or gamma-globulin increase was detected in 80% of patients. Abnormalities were more pronounced in HBsAg-positive cases and among them in subjects carrying anti-delta. Further follow-up studies are needed to clarify the long-term prognosis of liver disease in hemophiliacs.

Adolescent↗
PubMedDate not supplied

Kaposi's sarcoma as clinical manifestation of the acquired immunodeficiency syndrome in a hemophilic patient.

The authors report the natural history of HIV infection in a patient with severe hemophilia A who became HIV-seropositive in 1983 and, four years later, developed full-blown AIDS associated with a disseminated Kaposi's sarcoma. Neutralizing antibody titers against HIV were shown to be inversely disease-associated, while the progression of clinical symptoms was directly related to the decline of T4 cells and the increase of urinary neopterin levels. It is suggested that the presence of an HLA DR 5 phenotype and repeated CMV infection could have been crucial for the development of KS.

Acquired Immunodeficiency Syndrome↗