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Biomedical subjects

L M Aledort

Publications and source records attributed to L M Aledort.

At least 19 recordsLinked to original sources
PubMed1992

Incidence of lymphomas and other cancers in HIV-infected and HIV-uninfected patients with hemophilia.

OBJECTIVE: To determine the types and rates of cancers occurring in excess in the presence of infection with the human immunodeficiency virus type 1 (HIV-1). DESIGN: Cohort analytic study of HIV-infected and HIV-uninfected subjects followed for up to 12 years. SETTING: Fifteen hemophilia treatment centers. PATIENTS: A total of 1701 patients with hemophilia, of whom 1065 (63%) were HIV-1 seropositive. MAIN OUTCOME MEASURES: Morphologic classification and incidence rates of cancers. MAIN RESULTS: The incidence of non-Hodgkin's lymphoma after HIV seroconversion averaged 0.15 case per 100 person-years (95% confidence interval [CI], 0.08 to 0.25) and rose exponentially with increasing duration of HIV infection. Although the greatest absolute risk of lymphoma was in the oldest age group, the relative increase compared with general population rates was 38-fold in subjects 10 to 39 years old and 12-fold in older subjects (P less than .05). The CD4+ T-lymphocyte levels for lymphoma cases were similar to HIV-positive subjects without the acquired immunodeficiency syndrome (AIDS) who had been infected for the same length of time. The incidence of Kaposi's sarcoma was increased 200-fold (95% CI, 20 to 700). The incidence of cancers other than non-Hodgkin's lymphoma and Kaposi's sarcoma were not increased in the HIV-positive subjects (ratio of observed to expected cases, 0.9 [95% CI, 0.4 to 1.9]). The HIV-negative subjects had no significant increase in cancer incidence. CONCLUSIONS: HIV infection has restricted effects on cancer incidence that are only partly explained by immunosuppression. Paradoxically, improvements in therapy of HIV infection that prolong survival may lead to further increases in HIV-associated lymphoma.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Variability in serial CD4 counts and relation to progression of HIV-I infection to AIDS in haemophilic patients. Transfusion Safety Study Group.

OBJECTIVE--To examine the CD4 count and its near term changes relative to progression to AIDS within 30 months and to subsequent CD4 counts. DESIGN--Longitudinal clinical and laboratory study. SETTING--Haemophilia treatment centres in six large American cities. PATIENTS--555 people with congenital clotting disorders who were infected with HIV, initially without AIDS, and seen at follow up for 6-30 months in 1986-9. MAIN OUTCOME MEASURES--Absolute CD4 counts and incidence of AIDS. RESULTS--Outset CD4 count and age were independently related to progression to AIDS (p less than 0.0001 and p less than 0.005 respectively). Patients with CD4 counts of 0.30-0.49 x 10(9) cells/l had an age adjusted risk of AIDS within 30 months of only 9% that of patients with counts less than 0.20 x 10(9)/l. Children under 10 years old had only 16% of the CD4 adjusted risk of AIDS of people aged greater than or equal to 45 years. Analysis of 149 patients' CD4 counts at the beginning and end of two successive six month intervals showed an average decrease of 11% in each six months regardless of the outset count (greater than or equal to 0.20 x 10(9)/l). For individual patients the decrease in the second six month period was unaffected by the decrease in the first six month period. CONCLUSIONS--Antiviral treatment of asymptomatic people, particularly children, with CD4 counts greater than or equal to 0.3 x 10(9)/l is questionable if predicted on near term progression to AIDS. Because of individual CD4 count variability and the low rate of progression to AIDS near term declines in individual CD4 counts are a poor index for identifying people who will rapidly progress to AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Low risk of viral infection after administration of vapor-heated factor VIII concentrate. International Investigator Group.

A multicenter prospective study was carried out to evaluate whether a vapor-heated factor VIII concentrate transmitted blood-borne viral infections over a surveillance period of 15 months. Thirty-five patients with hemophilia and von Willebrand disease who had never received any blood components were treated. Twenty-eight were analyzed and found not to have non-A, non-B hepatitis. Sera from 20 of these 28 patients were also tested for the antibody to the hepatitis C virus. None had sero-converted during the follow-up period. None of the patients analyzed developed markers of the hepatitis B virus (n = 17) or the human immunodeficiency virus (n = 31). This vapor-heated factor VIII concentrate carries a low risk of transmitting hepatitis and human immunodeficiency virus infection.

Blood Transfusion↗
PubMed1991

Heterosexual co-transmission of hepatitis C virus (HCV) and human immunodeficiency virus (HIV).

OBJECTIVES: To determine the prevalence of antibodies to hepatitis C virus (HCV) in female sexual partners of multitransfused men with hemophilia and to compare the frequency of transmission of HCV and human immunodeficiency virus (HIV). STUDY DESIGN: Cross-sectional measurement of HCV and HIV antibodies. SETTING: Ten hemophilia treatment centers. PATIENTS: A total of 234 female sexual partners of 231 multitransfused men with hemophilia. MEASUREMENTS AND MAIN RESULTS: The prevalence of antibodies to HCV (anti-HCV) among female sexual partners of HCV-positive men was 5 of 194 (2.6%). Anti-HIV prevalence among female sexual partners of HIV-positive men was 25 of 196 (12.8%). Five (3%) of the 164 female sexual partners of HIV-positive/HCV-positive men were infected with HCV compared with none of the 30 female sexual partners of HIV-negative/HCV-positive men. Twenty-one (13%) of the 164 female sexual partners of HIV-positive/HCV-positive men were infected with HIV compared with 4 (13%) of 32 female sexual partners of HIV-positive/HCV-indeterminate men. The co-infected men were five times more likely to transmit both viruses than would be expected by chance (P = 0.01). When a single virus was transmitted to a female sexual partner, it was more often HIV than HCV (18 of 164 compared with 2 of 164, P = 0.001; odds ratio, 8.5; 95% Cl, 2.2 to 33.1). CONCLUSIONS: The higher prevalence of HCV in female sexual partners of men with hemophilia than in blood donor and other low-risk groups suggests that there is a low level of sexual transmission. Male to female sexual transmission of HCV is less efficient than that of HIV. The frequency of HCV transmission to sexual partners is five times higher when HIV is also transmitted, suggesting that HIV may be a cofactor for the sexual transmission of HCV.

Adult↗
PubMed1991

Intravenous anti-D treatment of immune thrombocytopenic purpura: analysis of efficacy, toxicity, and mechanism of effect.

The efficacy, toxicity, and mechanism of effect of intravenous Anti-D (Winrho) were studied in 43 Rh+ patients with immune thrombocytopenia purpura (ITP) who had not undergone splenectomy and in three already splenectomized patients. The mean platelet increase for the 43 nonsplenectomized patients was 95,000/microL (median 43,000/microL). Children had greater acute platelet responses than did adults. Human immunodeficiency virus status and duration of thrombocytopenia did not affect response. Maintenance treatment was given to patients as needed: the average interval between infusions was 24 days. The three splenectomized patients had no platelet response whatsoever. Toxicity was minimal; infusions were completed in less than 5 minutes. The generally accepted mechanism of effect of Anti-D has been Fc receptor blockade by substitution of antibody-coated red blood cells for antibody-coated platelets. Evidence is presented suggesting that the effect of IV Anti-D is not limited to Fc receptor blockade, including: (1) no correlation of parameters of hemolysis with platelet increase; (2) a 48- to 72-hour delay before platelet increase; (3) a tendency of the change in monocyte Fc receptor I expression to correlate with platelet increase; and (4) increased in vitro production of antibodies to sheep red blood cells following IV Anti-D infusion.

Adult↗
PubMed1991

Nasal spray desmopressin (DDAVP) for mild hemophilia A and von Willebrand disease.

OBJECTIVE: To evaluate the effect of a nasal spray preparation of desmopressin (DDAVP) on levels of factor VIII activity, ristocetin cofactor activity, and von Willebrand antigen as well as the length of bleeding time in patients with mild hemophilia A and von Willebrand disease; to determine whether effective hemostatic levels can be attained; and to compare the effect of this spray with that of standard intravenous desmopressin treatment. DESIGN: Before-and-after trial in patients known to respond to intravenous desmopressin. SETTING: Regional, comprehensive, hemophilia diagnosis and treatment center. PATIENTS: A total of 22 patients, including 11 patients with von Willebrand disease, 8 patients with mild hemophilia A, and 3 symptomatic hemophilia carriers. INTERVENTIONS: Patients were infused with desmopressin, 0.3 micrograms/kg body weight. At least 1 week later, they were taught to self-administer desmopressin nasal spray, 150 micrograms to each nostril. MEASUREMENTS: In patients with hemophilia, the level of factor VIII activity was measured; in patients with von Willebrand disease, levels of factor VIII activity, ristocetin cofactor activity, and von Willebrand antigen as well as bleeding time were measured before and after each administration of desmopressin. MAIN RESULTS: Desmopressin, when administered intravenously or intranasally, elevated levels of factor VIII, ristocetin cofactor, and von Willebrand antigen in both mildly hemophiliac patients and patients with von Willebrand disease when compared with baseline measures (P less than 0.05). Factor VIII levels adequate for hemostasis were achieved by 82% of the hemophiliac patients. An abnormal bleeding time was corrected in the majority (62%) of patients with von Willebrand disease. CONCLUSION: A nasal spray preparation of desmopressin apparently was effective both in treating bleeding episodes and when used prophylactically for minor surgical procedures in several patients.

Administration, Intranasal↗
PubMed1991

Treatment of von Willebrand's disease.

Early recognition that plasma infusions could correct the prolonged bleeding time and factor VIII deficiency in von Willebrand's disease (vWD) prompted major research efforts. Identification of the factor VIII molecule, its components, and its functions has provided critical information about replacement requirements to prevent or control bleeding. Plasma and cryoprecipitate have been the mainstay of therapy. Until recently, lyophilized coagulation factor concentrates had little usefulness in treating vWD. Current factor VIII concentrates prepared by monoclonal or recombinant technology (or both) are devoid of von Willebrand factor. Desmopressin has been a revolutionary synthetic agent useful in numerous patients with mild or moderately severe vWD. In many patients, however, desmopressin is ineffective. Only a few currently available factor VIII concentrates contain biologically active von Willebrand factor and can be used to prepare patients for surgical procedures or to stop hemorrhage. Inhibitors of von Willebrand factor arise de novo or in patients with vWD. Management with activated prothrombin complex concentrates or removal of antibody with protein A columns has been successful. Despite current technologic advances, not all patients with vWD can be successfully treated. Many problems with vWD continue to be unresolved.

Blood Transfusion↗
PubMed1991

Risk of human immunodeficiency virus type 1 infection among sexual and nonsexual household contacts of persons with congenital clotting disorders.

The status of human immunodeficiency virus type 1 (HIV-1) infection at the time of transmission to sexual contacts remains poorly defined. Transmission to nonsexual household contacts has appeared to be rare. A total of 505 sexual and nonsexual contacts of HIV-1-infected hemophiliacs in 349 households was observed. At entry, 10% of 201 sexual partners were anti-HIV-1-positive. Follow-up of 151 uninfected partners during a total of 351 person-years of observation showed no sero-conversions, although there were 13 pregnancies during that period. Eighty-seven percent of the seronegative respondents to a detailed questionnaire reported unprotected sexual contact at least occasionally. Among 304 other household members, including 108 parents who helped administer clotting factor concentrates to their children, none was seropositive at entry. Follow-up of 263 showed no seroconversions during a total of 605 person-years of observation. Thus, anti-HIV-1-positive hemophiliacs transmitted to their partners earlier in their course but were not found to do so when prospectively observed. No relationship to level of viremia as indicated by CD4 count, HIV-1 p24 antigenemia, or acquired immunodeficiency syndrome was found. Anti-HIV-1-positive hemophiliacs had not transmitted to their nonsexual household contacts before study entry and did not do so subsequently, indicating that the risk from even close nonsexual contact is extremely low.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Clinical efficacy of recombinant factor VIII. The rFactor VIII Clinical Trial Group.

This investigation has been an ongoing, multistage evaluation of the pharmacokinetics, safety and efficacy of a factor VIII concentrate prepared through recombinant DNA technology. In vivo activity of the rFVIII has been comparable to that of pdFVIII including half life and in vivo recovery. Recombinant factor VIII is safe and effective for prophylaxis and treatment of hemophilic bleeding episodes. Efficacy of rFVIII appears comparable with that of pdFVIII concentrates. Infusions were well tolerated with infrequent adverse reactions. As with any new product, the verdict regarding induction of inhibitors to factor VIII awaits evaluation of sufficient numbers of patients and passage of adequate observation time.

Adolescent↗
PubMed1990

Human recombinant DNA-derived antihemophilic factor (factor VIII) in the treatment of hemophilia A. recombinant Factor VIII Study Group.

BACKGROUND: Current treatment of hemophilia A, a hereditary disorder affecting approximately 1 in 10,000 males, relies on plasma-derived factor VIII concentrates. We tested the safety and efficacy of a recombinant factor VIII preparation for the treatment of this disorder. METHODS: We conducted the investigation in three stages: comparing the pharmacokinetics of plasma-derived and recombinant factor VIII, assessing the efficacy of recombinant factor VIII for home therapy, and assessing its efficacy for major surgical procedures and hemorrhage. A total of 107 subjects with hemophilia, 20 of whom had not been treated previously, enrolled in the investigation. RESULTS: The in vivo recovery and elimination half-lives of recombinant factor VIII equaled or exceeded those of plasma-derived factor VIII. Seventy-six subjects participated in a home-treatment program, using recombinant factor VIII for 69 to 807 days (median, 618); home diaries of 56 subjects treated for 5 months were analyzed. Of 540 bleeding episodes, 399 (73.9 percent) required only one treatment with recombinant factor VIII. The projected annual consumption of recombinant factor VIII was similar to that of plasma-derived factor VIII concentrate. Twenty-six subjects received recombinant factor VIII for 22 surgical procedures and 10 serious hemorrhages; hemostasis was excellent in all cases. De novo formation of inhibitors occurred in only 1 of 85 previously treated subjects. Inhibitor antibodies also developed in 6 of 21 children, 20 of whom had not previously been treated; 5 had low levels (less than or equal to 7.5 Bethesda units) despite continued treatment with recombinant factor VIII. There was no evidence of new formation of antibody to foreign proteins, and recombinant factor VIII was well tolerated. CONCLUSIONS: Recombinant factor VIII has biologic activity comparable to that of plasma factor VIII and is safe and efficacious for the treatment of hemophilia A.

Adult↗
PubMed1990

Histocompatibility antigen patterns in haemophilic patients with factor VIII antibodies.

A number of studies suggest that there is a genetic basis for the formation by some haemophilia A patients of antibodies that inactivate factor VIII. In our study, human leucocyte antigen (HLA)-A, B, C, DR and DQ typing was carried out for 44 haemophilia A patients, including 16 who had developed an antibody to factor VIII. In contrast to previous reports, we found no association between HLA-DR antigens and haemophilia A per se or the formation of a factor VIII inhibitor. However, there was an absence of HLA-Cw5 in the 16 haemophilic patients who had formed an antibody to factor VIII. This finding, consistent with a previous report, identified a statistically significant difference in HLA-Cw5 frequency when the inhibitor patient group was compared to multi-transfused haemophilic patients who had no inhibitor (11/28).

Adolescent↗
PubMed1990

Transmission of human immunodeficiency virus type 1 by dry-heated clotting factor concentrates. Transfusion Safety Study Group.

The Transfusion Safety Study monitored susceptible persons for human immunodeficiency virus type 1 (HIV-1) infections transmitted by plasma products and blood components. Through December, 1988, 6 subjects without antibody to HIV-1 (anti-HIV-1) became seropositive after receiving dry-heated factor VIII concentrate. The preparations implicated in 3 cases were derived entirely from anti-HIV-1-screened donors. In all instances, HIV-1 infection could be explained by concentrates heated at 60 degrees C for 24-30 h. Limiting consideration to concentrates and components administered after study entry showed that 4 of the seroconversions occurred among 122 subjects given 10 million units of factor VIII concentrates. No seroconversions occurred among 84 subjects given 5 million units of factor IX concentrates, or 83 who received components from over 26,000 unpaid donations. Serologic surveillance of anti-HIV-1-negative subjects provides important information, and should be routine in the management of persons receiving clotting factor concentrates.

Acquired Immunodeficiency Syndrome↗
PubMed1989

A prospective study of human immunodeficiency virus type 1 infection and the development of AIDS in subjects with hemophilia.

We evaluated a multicenter cohort of 1219 subjects with hemophilia or related disorders prospectively, focusing on 319 subjects with documented dates of seroconversion to human immunodeficiency virus type 1 (HIV-1). The incidence rate of the acquired immunodeficiency syndrome (AIDS) after seroconversion was 2.67 per 100 person-years and was directly related to age (from 0.83 in persons 1 to 11 years old up to 5.66 in persons 35 to 70 years old; Ptrend = 0.00003). The annual incidence of AIDS ranged from zero during the first year after seroconversion to 7 percent during the eighth year, with eight-year cumulative rates (+/- SE) of 13.3 +/- 5.3 percent for ages 1 to 17, 26.8 +/- 6.4 percent for ages 18 to 34, and 43.7 +/- 16.4 percent for ages 35 to 70. Serial immunologic and virologic markers (total numbers of CD4 lymphocytes, presence of serum interferon or HIV-1 p24 antigen, and low or absent serum levels of anti-p24 or anti-gp120) predicted a high risk for the subsequent development of AIDS. Adults 35 to 70 years old had a higher incidence of low CD4 counts than younger subjects (P less than or equal to 0.005), whereas adolescents had a low rate of anti-p24 loss (P = 0.0007) and subjects 1 to 17 years old had a lower incidence of AIDS after loss of anti-p24 (P = 0.03). These findings not only demonstrate that the risk of AIDS is related directly to age but also suggest that older adults are disproportionately affected during the earlier phases of HIV disease, that adolescents may have a low replication rate of HIV, and that children and adolescents may tolerate severe immunodeficiency better because they have fewer other infections or because of some unmeasured, age-dependent cofactor or immune alteration in the later phase of HIV disease.

Acquired Immunodeficiency Syndrome↗
PubMed1989

A codon 338 nonsense mutation in the factor IX gene in unrelated hemophilia B patients: factor IX338 New York.

Hemophilia B is an X-linked recessive bleeding disorder resulting from a deficiency of the coagulation factor IX (FIX) protein activity, a vitamin K-dependent serine protease active in both the intrinsic and extrinsic coagulation systems. DNA analyses of the factor IX gene in two unrelated patients with severe hemophilia B, with a IX coagulant activity less than 1% and undetectable FIX antigen, detected the loss of the second TaqI site in exon h (VIII) in both individuals. Polymerase chain reaction (PCR) amplification of 576 base pairs of exon h (VIII) with cloning and dideoxy sequencing of cloned DNA from one hemophiliac revealed a single C----T transition in codon 338 that changes an arginine residue codon CGA to a nonsense codon TGA. Allele-specific oligonucleotide probe hybridization with a mutant (C----T) and a wild-type allele confirmed the same mutation in amplified genomic DNA of the second hemophilia patient. The C----T transition represents another example of mutation at a CpG dinucleotide. DNA polymorphism analysis of the FIX gene in both individuals revealed each to be on a separate FIX haplotype; therefore, predicting each to be a separate mutation event.

Amino Acid Sequence↗