Prevalence of human immunodeficiency virus type 1 DNA in hemophilic men and their sex partners. Hemophilia-AIDS Collaborative Study Group

Polymerase chain reaction (PCR) was used to detect human immunodeficiency virus (HIV)-1 DNA in peripheral blood mononuclear cells to assess in hemophilic men whether any were HIV-seropositive but uninfected or seronegative but infected and in seronegative sex partners of seropositive hemophilic men whether any were infected. Of 40 seropositive men, 38 (95%) were PCR-positive; one was PCR-indeterminate and one PCR-negative. None of 41 seronegative men who used only donor-screened, virus-inactivated coagulation factor products were PCR-positive. However, two of six who received noninactivated products were PCR-positive; one had low T-helper cell counts and died of unrelated causes and the other had seroconverted 11 mo later. PCR with a second primer pair also detected HIV-1 DNA in these two men. None of 25 seronegative female sex partners of seropositive men, including six men with AIDS and seven with AIDS-related symptoms, were PCR-positive. These data suggest that most seropositive hemophilic men are HIV-infected; whether some are infected with defective virus remains to be resolved as does the infection status of seropositive PCR-negative men. Identification of two seronegative PCR-positive men supports the possibility that HIV-1 DNA can be detected before seroconversion.     

Concordance of polymerase chain reaction with human immunodeficiency virus antibody detection

To evaluate the correlation of detection of human immunodeficiency virus (HIV) by polymerase chain reaction (PCR) with detection of HIV antibody, 271 simultaneous serum and peripheral blood mononuclear cell samples were examined from 242 persons whose activities placed them at increased risk for HIV infection: 142 from homosexual men, 86 from hemophilic men, and 43 from heterosexual partners of HIV-infected persons. PCR was performed using the gag region primer pair SK38/39 and the env region primer pairs SK68/69 and CO71/72. Amplified HIV DNA was detected using specific oligomer probes. Of 63 HIV antibody-positive samples, 58 (92%) had HIV DNA by PCR. Of 208 HIV antibody-negative samples, 7 (3.4%) had HIV DNA by PCR. On follow-up, 4 of the latter persons were seropositive when next tested; 2 were well and antibody- and PCR-negative; 1 had died of a stroke before retesting. Thus, PCR detects HIV in most antibody-positive persons; detection is increased by use of multiple primer pairs. PCR-positive antibody-negative specimens may indicate HIV infection in which antibody has not yet developed or may be false-positive PCR results. When PCR is discordant with HIV antibody, testing of additional specimens and clinical follow-up are necessary to assess HIV infection status.     

Anticoagulant protein C pathway defective in majority of thrombophilic patients [see comments]

A defect involving poor anticoagulant response to activated protein C (APC), an anticoagulant serine protease known to inactivate factors Va and VIIIa in plasma, was recently reported and the existence of a novel APC cofactor was suggested. To define the frequency of this defect among 25 venous thrombophilic patients with no identifiable laboratory test abnormality and among 22 patients previously identified with heterozygous protein C or protein S deficiency, the APC-induced prolongation of the activated partial thromboplastin time assay for these patients was compared with results for 35 normal subjects. The results show that this new defect in anticoagulant response to APC is surprisingly present in 52% to 64% of the 25 patients, ie, in the majority of previously undiagnosed thrombophilia cases, but is not present in 20 of 22 heterozygous protein C or protein S deficient patients, suggesting that the new factor is a risk factor independent of protein C or protein S deficiency. The results demonstrate that abnormalities in the anticoagulant protein C pathway are present in the majority of thrombophilic patients.     

Distinct variants of erythrocyte protein 4.1 inherited in linkage with elliptocytosis and Rh type in three white families

Hereditary elliptocytosis is a heterogeneous disorder resulting from defects in the erythrocyte membrane skeleton. Although some cases of elliptocytosis result from defects in spectrin, the specific structural abnormality has yet to be identified in the majority of cases. Protein 4.1 plays an essential role in erythrocyte membrane physiology, and deficiencies have been implicated in only a few rare cases of elliptocytosis. By using 4.1 immunoblots and a 4.1 radioimmunoassay we identified distinct variants of protein 4.1 in 15 elliptocytic members of three US white families with the Rh-linked form of elliptocytosis. Elliptocytic members of family G were heterozygotes for a low-molecular weight (mol wt) 4.1 variant (65,000 to 68,000 daltons; normal, 80,000) inherited in linkage with the Rz phenotype. Elliptocytic members of family C expressed a simple partial deficiency of protein 4.1 (63% of the normal level) that was inherited in linkage with the r phenotype. Elliptocytic members of family N were heterozygotes for a high-mol wt 4.1 variant (100,000 daltons) also inherited in linkage with the r phenotype. These studies indicate that mutant forms of protein 4.1 are not uncommon in elliptocytosis among whites and that different kindreds probably express different mutations. The observed linkage of elliptocytosis and Rh blood type most likely results from the close proximities of the 4.1 gene (site of the mutation) and the Rh gene, which is located nearby on the short arm of chromosome 1.     

Comprehensive care for haemophilia around the world

Summary.  Comprehensive haemophilia care has been defined as the continuing supervision of all medical and psychosocial factors affecting the person with haemophilia family. Services offered by haemophilia treatment centres (HTCs) adopting the comprehensive care model include establishing prophylaxis and other treatment protocols, development of psychosocial, education and research programme, maintenance of a patient registry, genetic and reference diagnostic services and orchestration and management of a wide variety of multidisciplinary interventions. Most centres practising this model of care are based in developed countries and can meet costs for plentiful treatment products through government or insurance-company funding. Not all the programmes are dependent on the level of product supply, however, and many have been supported in countries with emerging economies as part of national healthcare systems, particularly in relation to blood management. In this paper we present perspectives from different areas of the world on how to adopt, adapt and achieve economically appropriate models of comprehensive care.     

Differential effects of sequential, simultaneous, and single agent interleukin-3 and granulocyte-macrophage colony-stimulating factor on megakaryocyte maturation and platelet response in primates.

Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) following interleukin-3 (IL-3) priming has been shown to increase thrombopoiesis. To elucidate the comparative abilities of IL-3 and GM-CSF in influencing megakaryocyte development in vivo, serial bone marrow analyses were performed on rhesus monkeys treated with 5 micrograms/kg/d of IL-3 and 5 micrograms/kg/d of GM-CSF sequentially for 4 days each, simultaneously for 8 days, and as single agents for 8 days. Platelet counts maximally increased to a mean of 7.5 x 10(5)/microL (n = 3) on days 11 through 12 in monkeys treated with sequential IL-3/GM-CSF. In contrast, neither IL-3 alone nor simultaneously administered IL-3/GM-CSF elicited increases in thrombopoiesis between days 3 and 15. GM-CSF elicited a variable platelet response. Megakaryocyte ploidy distributions were significantly (P < .001) shifted between days 7 and 10 in monkeys treated sequentially and between days 3 and 15 in monkeys treated with combined IL-3/GM-CSF and with GM-CSF alone but not in monkeys treated with IL-3 alone. The changes in mean DNA content and megakaryocyte size, as determined by digital image analysis, were larger in monkeys treated with sequential IL-3/GM-CSF and with GM-CSF alone than in simultaneously treated monkeys. In addition, sequentially but not simultaneously treated monkeys showed increased numbers of megakaryocytes on bone marrow biopsy. We conclude that administration of IL-3 followed by GM-CSF treatment increases thrombopoiesis by sequentially increasing megakaryocyte numbers and maturation and that these effects are diminished by simultaneous administration of the two cytokines.     

Erythroid failure in Diamond-Blackfan anemia is characterized by apoptosis

Programmed cell death, also known as apoptosis, is frequently initiated when cells are deprived of specific trophic factors. To investigate if accelerated apoptosis contributes to the pathogenesis of Diamond- Blackfan anemia (DBA), a rare pure red blood cell aplasia of childhood, we studied the effect of erythropoietin (epo) deprivation on erythroid progenitors and precursors from the bone marrow of DBA patients as compared with hematologically normal controls. Apoptosis in response to epo deprivation was evaluated by enumeration of colony-forming unit- erythroid (CFU-E)- and burst-forming unit-erythroid (BFU-E)-derived colonies in plasma clot semisolid culture and by the identification of typical DNA oligosomes by gel electrophoresis from marrow mononuclear cells in liquid culture. In all DBA patients there was a marked decrease in CFU-E- and BFU-E-derived colony formation compared with normal controls at comparable time points of epo deprivation, with a complete loss of CFU-E-derived colonies in semisolid culture by 9 hours of epo deprivation versus 48 hours in controls. The BFU-E-derived colony response to epo deprivation displayed a similar pattern of decrement. Apoptotic changes assessed by the presence of characteristic DNA fragmentation began in the absence of epo deprivation and were readily detected within 3 hours of epo deprivation in DBA cultures versus 9 hours in controls. We conclude that DBA is characterized by accelerated apoptosis as measured by the loss of erythroid progenitor clonogenicity and increased progenitor and precursor DNA fragmentation leading to the formation of characteristic oligosomes, consistent with an intrinsic erythroid-progenitor defect in which increased sensitivity to epo deprivation results in erythroid failure.