Sex-related differences in hemostasis and thrombosis.

Disorders of thrombosis and hemostasis represent both diagnostic and therapeutic challenges for the clinician, in part because of sex-based differences in incidence and presentation. The hemophilias are characterized by specific sex-linked patterns of inheritance, and there are sex differences in the presentation of the autosomally inherited disorders, particularly von Willebrand's disease. The diagnosis of these disorders can be affected by variations in either endogenous or exogenous estrogens, and the hemostatic stresses presented by menstruation and childbirth render any coagulopathy more severe in females than in males. Women are also at increased risk for developing thrombotic and embolic problems while on exogenous estrogens and during pregnancy. This article presents recommendations about the most appropriate and cost-effective ways to screen for the inherited disorders of both thrombosis and hemostasis in men and women. Recommendations are also developed for the treatment of women with these disorders, particularly in the context of pregnancy, contraception, uterine bleeding, and postmenopausal management.

Liver failure and mortality in HIV-positive haemophiliacs: FOURTEEN-YEAR EXPERIENCE AND LITERATURE REVIEW.

Progression to clinical liver failure has been observed in hepatitis C (HCV)-infected, HIV-seropositive haemophiliacs. We studied the records of 176 haemophiliacs who were infected with HIV and/or HCV seen between 1980 and 1993. Thirty-two of 113 (28%) HIV-seropositive patients died during the study period. Ten of these patients died of liver failure, representing 31% of all mortality. An additional four HIV-seropositive patients who died of other causes had end-stage liver disease. Clinical liver failure occurred in 12% of the HIV-infected cohort. None of the HIV-seronegative, HCV-infected patients suffered from liver failure. Among HIV-infected patients, liver failure was associated with advanced age and decreased CD4 counts. Severe, sporadic ALT elevations were associated with liver failure; persistent transaminase elevations were associated with mortality. We conclude that HIV infection enhances progression of HCV infection to clinical liver failure, and that liver failure is a major cause of mortality in HIV-positive haemophiliacs.

Risks of immunodeficiency, AIDS, and death related to purity of factor VIII concentrate. Multicenter Hemophilia Cohort Study.

In HIV-infected subjects with haemophilia, CD4 counts seem to fall more slowly in those on high-purity factor VIII (FVIII) than on intermediate-purity product. We evaluated whether risks for AIDS or death were associated with either product among 411 HIV-infected individuals. The relative hazard of AIDS was slightly elevated for both current (1.34) [corrected] and cumulative (1.01 per month) use of high-purity products (neither significant). The corresponding hazards for death were 1.49 and 1.03 (neither significant). Thus we found no evidence that high-purity FVIII concentrates retard the development of AIDS.

Three-year randomised study of high-purity or intermediate-purity factor VIII concentrates in symptom-free HIV-seropositive haemophiliacs: effects on immune status.

The availability of monoclonal-antibody-purified factor VIII (FVIII) concentrates allows us to test the hypothesis, based on in vitro observations, that their use in HIV seropositive haemophiliacs would result in a difference in the rate of deterioration of immune function. We designed a multicentre, prospective, randomised, controlled study of symptom-free HIV-infected patients with haemophilia A who were assigned to receive either an intermediate-purity or monoclonal-antibody-purified product. All had CD4 lymphocyte counts of 100-600/microL, were negative for hepatitis B surface antigen, had not received any antiretroviral or immunomodulating drugs before study entry, and had previously received replacement therapy with intermediate purity FVIII concentrates. Use of antiretroviral therapy was permitted. 60 patients were recruited and 30 were assigned to each group. 35 completed the 3 year study, 20 in the monoclonal arm and 15 in the intermediate-purity arm. Among those completing the study, there were no differences between the two groups in the occurrence of AIDS-defining diagnoses (1 in each group). There were, however, striking and significant differences in terms of changes in absolute CD4 counts. The group receiving monoclonal-antibody-purified concentrates had essentially stable counts while a significant drop was observed in the group receiving intermediate-purity FVIII. These differences were independent of the use of antiretroviral therapy. These observations support the use of high-purity concentrates in the treatment of symptom-free HIV-positive patients with haemophilia A, and they should be taken into account along with cost, by doctors making therapeutic decisions.

Congenital bleeding disorders. Rational treatment options.

There are rational, effective choices available for the treatment of common inherited bleeding disorders, according to assessment of safety, efficacy and cost. All currently available products for patients with haemophilia A (factor VIII deficiency) are comparable in terms of efficacy and viral safety. However, high purity products are recommended for those with coexisting human immunodeficiency virus (HIV) infection. Many patients with mild haemophilia A and most with von Willebrand's disease can be treated with desmopressin, which can be given as an intranasal spray in some countries. For the treatment of patients with factor XI deficiency, fresh frozen plasma remains the standard care, although solvent-detergent-treated fresh frozen plasma and factor XI concentrate are currently being investigated as alternatives. In the treatment of haemophilia B (factor IX deficiency), purified factor IX concentrates are particularly useful in clinical settings where large amounts of concentrate are to be used (e.g. surgical prophylaxis). Their usefulness in other contexts needs clarification. Treatment of inhibitors that may develop in response to administered coagulation factors is still limited to the use of prothrombin complex concentrates and porcine factor VIII. Active clinical trials are currently assessing the efficacy and safety of recombinant factor VIIa, Xa and tissue factor in this indication.

HL-T, a new cell line derived from HL-60 promyelocytic leukemia cell cultures expressing terminal transferase and secreting suppressor activity.

A cell line with immature blast cell morphology was isolated from HL-60 promyelocytic leukemia cell cultures and designated HL-T. This new cell type is biphenotypic, expressing terminal transferase (TdT) together with myelomonocytoid immunologic features. TdT enzymatic activity, undetectable in HL-60, was determined to be 140 to 180 units/10(8) HL-T cells by the dGTP-assay, approximately 20% of the activity found in lymphoblastoid cell lines. HL-T predominantly synthesize the known 58-kDa TdT-protein plus a minor 54/56-kDa doublet. The 58-kDa steady state form is nonglycosylated and is phosphorylated. Precursor antigens S3.13 and MY-10, absent on HL-60, are expressed by HL-T; however, the cells are negative for HLA-Dr. Southern blot analysis by hybridization with immunoglobulin heavy chain (JH) and T cell-receptor chain gene (T beta) probes shows JH to be in the germ-line configuration in both cell lines and the T beta gene to be in germ-line in HL-60 but to be rearranged in HL-T. Truncation of the gene encoding the granulocyte-macrophage-colony-stimulating factor (GM-CSF), as found in HL-60, is not observed in HL-T. HL-T are resistant to differentiation-induction by retinoic acid and 1,25-dihydroxyvitamin D3. Cytogenetically HL-T share with HL-60 a deletion of the short arm of chromosome 9 at breakpoint p13, an aberration frequently found in patients with T cell leukemia. In addition, HL-T display t(8;9)(p11;p24) and trisomy 20. Tetraploidy is observed in 80% of HL-T metaphases with aberrations identical to those in the diploid karyotype. Like HL-60, the new line shows some surface-antigenic-T cell characteristics. Despite an antigenic pattern most consistent with that of helper-inducer T cells (T4+, D44+/-, 4B4+, 2H4-, TQ1+/-), HL-T cells and their conditioned culture medium suppress antigen, mitogen, and mixed-leukocyte-culture-mediated lymphocyte proliferation.

High frequency of clonal immunoglobulin or T cell receptor gene rearrangements in acute myelogenous leukemia expressing terminal deoxyribonucleotidyltransferase.

Ig and T cell receptor rearrangements have been used as irreversible markers of lineage and clonality in the study of B- and T-lymphoid populations. We have addressed the issue of lymphoid lineage specificity of these rearrangements by analyzing a panel of 25 TdT- acute myelogenous leukemias, 13 TdT+ AMLs, and 4 TdT+ undifferentiated leukemias. We report that while gene rearrangements represent extremely rare events in classical TdT- AML (less than 8%), rearrangements of either the Ig or T beta locus or both were detectable in the majority of the TdT+ AMLs (greater than 60%), and rearrangements of both loci were detectable in all of the TdT+ undifferentiated leukemias. These data demonstrate a significant association between TdT expression and Ig or T beta gene rearrangements even outside the lymphoid lineage, further supporting a role for TdT in Ig and T cell receptor gene assembly. These data also indicate that a coordinated program of lymphoid gene expression involving TdT-CD7-expression and Ig/T beta rearrangements can be activated before myeloid commitment. Whether the activation of this program represents a normal, albeit rare, event in early myelopoiesis or a transformation-related event present only in leukemic cells remains to be determined.

Biochemistry and expression of myelomonocytic antigens.

Six monoclonal antibodies (MAb) which react with myelomonocytic cells representing various stages of differentiation, and which precipitate six different cell surface molecules, were identified. A 50 to 55 kilodalton (Kd) glycoprotein, restricted in expression to mature cells of the monocyte lineage, was detected by immunoprecipitation with antibody MoS39. By using COS-7 cells transfected with a cDNA clone encoding the MoS39 antigen, various well-described anti-monocyte MAb, including Mo2, My4, Leu-M3 (MoP9), MoP15, MoS1, and 63D3, also bound to MoS39-expressing COS-7 cells, suggesting that this group of antibodies reacted with the same glycoprotein. Immature cells of the myelomonocytic lineage were shown to express two distinct molecules: one with an m.w. of 26 to 28 Kd identified by antibody SG133, and the second, a 130 to 140 Kd glycoprotein identified by MoU26. Mature granulocytes were found to express a 60 Kd molecule identified by antibody SG185 which was absent from other cells of this lineage. Two other molecules were shown to be present on both mature and immature cells of the granulocytic and monocytic lineages: a 130 to 140 Kd glycoprotein identified by antibody SG134, and a 160 to 170 Kd glycoprotein recognized by antibody MoU48.