Human immunodeficiency virus (HIV) type 1 infection status and in vitro susceptibility to HIV infection among high-risk HIV-1-seronegative hemophiliacs

Blood samples were obtained from 16 hemophiliacs who had a 50%-94% defined risk of human immunodeficiency virus (HIV) type 1 infection on the basis of treatment history and from 14 controls not at risk for HIV infection. HIV-1 was not detected in any of 12 patient samples by cocultivation nor in 14 patient samples by the polymerase chain reaction. Peripheral blood cells from 7 seronegative hemophiliacs at highest risk of seroconversion (94%) were less susceptible to HIV-1 infection in vitro than were cells from healthy controls (P < .025, one-tailed Wilcoxon rank sum test). In contrast, the susceptibility to HIV-1 infection of lymphocytes from 6 seronegative hemophiliacs at moderate risk (50%-56%) of seroconversion did not differ from that of cells from controls or from high-risk hemophiliacs. Therefore, prolonged periods of seronegative HIV-1 infection are not common in this high-risk population. In addition, among hemophiliacs there may exist heterogeneity in susceptibility to HIV-1 infection in vitro and in vivo.

Variability of in vivo recovery of factor IX after infusion of monoclonal antibody purified factor IX concentrates in patients with hemophilia B. The Mononine Study Group

Monoclonal antibody purified factor IX concentrate, Mononine (Armour Pharmaceutical Company, Kankakee, Illinois, USA), is a recently developed replacement factor concentrate for the treatment of patients with hemophilia B. The pharmacokinetic properties of monoclonal antibody purified factor IX concentrate (MAb Factor IX concentrate) have been evaluated in only small samples of patients, and little is known about those factors that might influenced in vivo recovery of factor IX after infusion is a larger patient population. In vivo recovery of factor IX was therefore evaluated for 80 different indications in 72 patients who received MAb Factor IX concentrate for the management of spontaneous or trauma-induced bleeding, or as prophylaxis with surgery. The average recovery after infusions for presurgical pharmacokinetic analysis (mean +/- standard deviation) was 1.28 +/- 0.56 U/dl rise per U/kg infused (range 0.41-2.80), and the average recovery after all infusions for treatment was 1.23 +/- 0.49 U/dl rise per U/kg infused (range - 0.35-2.92). Recovery values for multiple MAb Factor IX doses in a given patient were also variable; the average recovery was 1.22 +/- 0.53 U/dl rise per U/kg given, and standard deviations ranged from 0.03 to 1.26. Patient age, weight, and MAb Factor IX concentrate dose minimally but significantly influenced factor IX recovery. There was no significant effect of either race, history of previous thrombotic complications during treatment with other replacement factor concentrates, or bleeding state on recovery. All of the patients treated with this preparation experienced excellent hemostasis, and no thrombotic complications were observed.

Safety of high doses of a monoclonal antibody-purified factor IX concentrate. The Mononine Study Group

This report summarizes safety and efficacy information among patients treated with high doses (> 75 U/kg) of a monoclonal antibody-purified factor IX concentrate [coagulation factor IX (human) monoclonal antibody purified)] in two clinical trials. One hundred infusions of this factor IX concentrate at doses > 75 U/kg were administered to 35 patients, six of whom had experienced thrombotic complications during previous treatment with prothrombin complex concentrate. Hemostasis in all patients was rated as "excellent," and there were no thrombotic complications.

Safety and recovery of mononine in multiple-dose, high-dose regimens

Prothrombin complex concentrates (PCCs) have been used for the treatment of hemorrhagic episodes in patients with hemophilia B but have been associated with a high incidence of thrombotic complications. Newer, ultrapure concentrates of factor IX contain less extraneous proteins than PCCs and are less thrombogenic in vitro. In this report, the results of clinical studies with Mononine (Armour Pharmaceutical Company), a purified factor IX concentrate prepared by monoclonal affinity chromatography, are described. Two studies were performed, a phase I/II clinical trial in 10 patients and a compassionate use study in 72 patients. The pharmacokinetics of Mononine were found to be similar to the pharmacokinetics of factor IX after administration of PCCs. In both studies, Mononine was well-tolerated and hemostatically effective when used in doses of up to 161 IU/kg in treatment courses of up to 67 infusions of Mononine. Patients with hepatitis and a prior history of thrombosis with PCCs tolerated Mononine with no evidence of thrombosis. The only thrombotic complication attributed to Mononine in the two studies was an episode of phlebitis at the site of an intravenous line in one patient. These studies indicate that Mononine is safe and effective in the treatment of hemorrhagic episodes in patients with hemophilia B.

Rapid characterisation of Candida albicans by pyrolysis mass spectrometry

Clinical isolates (41) of Candida spp. from three possible outbreaks of nosocomially-acquired infection were compared by pyrolysis mass spectrometry (PMS) and by a combined morphotyping and resistotyping (M-R typing) method. Both systems characterised all the isolates and distinguished one isolate of C. tropicalis and another of C. glabrata from the 39 isolates of C. albicans. Results from both systems suggested that cross-infection with a single strain contributed to two of the outbreaks. In several instances, more than one strain of C. albicans was found amongst multiple isolates from the same patient. PMS is a simple, rapid and objective technique capable of characterising C. albicans isolates; discrimination was similar to M-R typing.

Incorporation of Rap 1b into the platelet cytoskeleton is dependent on thrombin activation and extracellular calcium

Rap 1b is a 22-kDa low molecular mass GTP-binding protein which is both a member of the Ras superfamily and a substrate for cAMP-dependent protein kinase. Recently, evidence has been presented to show that Rap 1b is incorporated into the detergent-extracted cytoskeleton of platelets during thrombin-induced activation. The aims of this study were to compare the incorporation of Rap 1b into the detergent-extracted cytoskeleton after activation with different agonists, to examine the role of extracellular calcium on the incorporation of Rap 1b into the cytoskeleton, to investigate the relationship between the association of Rap 1b and other proteins with the cytoskeleton, and to determine the effect of phosphorylation of Rap 1b incorporation into the cytoskeleton. Platelets were activated with thrombin, A23187, phorbol myristate acetate, ADP, epinephrine, and collagen in the presence and absence of calcium. The time dependence of Rap 1b incorporation into the detergent-extracted cytoskeleton was then measured. When platelets were activated by thrombin in the presence of extracellular calcium, conditions which permit aggregation, incorporation of Rap 1b into the detergent-extracted cytoskeleton was biphasic. Approximately 20% of the total cellular Rap 1b incorporated into the cytoskeleton within seconds and was followed by a slower second phase of incorporation. In contrast, when platelets were activated by thrombin in the absence of calcium, conditions which inhibit aggregation, or by the other agents in the presence or absence of calcium, only the initial phase of Rap 1b incorporation into the cytoskeleton was measured. The incorporation of Rap 1b paralleled the incorporation of membrane glycoproteins (GP) IIb/IIIa and PECAM-1, but not the incorporation of pp60c-src. The GTPase-activating protein for Ras (Ras-GAP) did not associate with the detergent-extracted cytoskeleton. Two-dimensional isoelectric focusing SDS-polyacrylamide gel electrophoresis of the total cellular and cytoskeletal Rap 1b showed that unphosphorylated as well as phosphorylated isoforms of Rap 1b were incorporated into the cytoskeleton in the same molar ratio as was present in the intact cell. Furthermore, the rates of incorporation of phosphorylated and unphosphorylated Rap 1b into the cytoskeleton were similar. These experiments show that Rap 1b can regulate events that take place within seconds after activation, such as the initial formation of the cytoskeleton, as well as longer term changes in the cytoskeleton that occur in response to thrombin-induced aggregation. Furthermore, phosphorylation could modulate the (unknown) functions of Rap 1b as a component of the cytoskeleton.

Increasing incidence of cryptococcosis in the United Kingdom

The incidence of infection with Cryptococcus neoformans in the United Kingdom during the years between 1953 and 1981 is compared with that between 1982 and 1991. The patients were those from whom samples were submitted to the PHLS Mycological Reference Laboratory (MRL), or those in whom the disease was confirmed elsewhere in the United Kingdom and reported to PHLS Communicable Disease Surveillance Centre (CDSC). In all, 83 cases were identified between 1953 and 1981 and 322 between 1982 and 1991, 201 of which were known to be HIV-associated. The incidence of infection with Cryptococcus neoformans has increased four-fold in the last decade. It is an increasing cause of infection in immunosuppressed patients, most notably those with HIV infection. Currently, 4.0% patients with AIDS in the United Kingdom are known to have developed cryptococcosis.

Hydrophobic affinity chromatography of human thrombin

Hydrophobic affinity chromatography on p-chlorobenzylamido-agarose (p-CBA-agarose) was used to characterize various modified forms of human thrombin. Native alpha-thrombin bound tightly to the column and was eluted with either acetonitrile or 1,4-dioxane, while the catalytically inactive prethrombin 2 did not bind to the matrix. Site-specific chemical modification with pyridoxal 5'-phosphate resulted in the loss of at least 80% of fibrinogen clotting activity but did not influence the binding of thrombin to p-CBA agarose. Modification of thrombin with pyridoxal 5'-phosphate is thought to occur at the fibrinogen-binding site and the heparin-binding site. In contrast, binding of thrombin to p-CBA agarose was eliminated by modification of the active site histidine using either H-D-phenylalanyl-L-prolyl-L-arginine chloromethylketone or dansyl-L-glutamyl-glycyl-L-arginine chloromethylketone but not with tosyl-L-lysine chloromethylketone. The presence of either hirudin or heparin blocked the binding of thrombin to p-CBA-agarose but dansyl-arginine-N-(3-ethyl-1,5-pentanediyl)amide had no effect. These results indicate that p-CBA agarose binds to thrombin outside of the enzyme active site and its use should be valuable in characterizing site-specific modified thrombins obtained by either protein engineering or chemical modification.

Human immunodeficiency virus-related conditions in children and adults with hemophilia: rates, relationship to CD4 counts, and predictive value

To further elucidate the natural history of human immunodeficiency virus (HIV) infection, we studied intermediate HIV-related conditions occurring before acquired immunodeficiency syndrome (AIDS) in a prospectively observed multicenter cohort of 738 HIV-infected persons with hemophilia. We analyzed the frequency in adults and children of common HIV-related conditions and the relative risk of AIDS after occurrence of these conditions, controlling for age at seroconversion and the percentage of CD4+ lymphocytes. Thrombocytopenia was the most frequently observed condition with cumulative incidences of 43% +/- 7% in adults and 27% +/- 6% in children and adolescents by 10 years after seroconversion. Oral candidiasis, fever, weight loss, and non-AIDS pneumonia were two to four times more common in adults than children, whereas herpes zoster risk was similar in the two age groups. HIV-related conditions were infrequent during the first 4 years of infection, particularly in children. With the exception of thrombocytopenia, mean CD4 counts were less than 350 cells/microL at the onset of the conditions. The relative hazard of AIDS after oral candidiasis was 18 in children and 3.8 in adults. Relative hazard in adults was also increased after persistent fever (10), weight loss (3.2), and non-AIDS pneumonia (2.2). Herpes zoster and thrombocytopenia were not significantly associated with AIDS in either age group. We conclude that intermediate HIV-related conditions occur more frequently in adults than in children with hemophilia. Persistent fever is the strongest predictor of AIDS in adults, whereas oral candidiasis is the strongest predictor in children. These findings should facilitate the design and conduct of clinical trials as well as the management of HIV-infected children and adults.

Cytoskeletal interactions of Rap1b in platelets

We have presented evidence that rap1b, a 22 kDa low molecular weight GTP binding protein, becomes associated with the cytoskeleton in thrombin-activated platelets. The initial incorporation is very rapid and occurs as fast as we can measure it. Thus, some rap1b is associated with the cytoskeleton as fast as it is formed. The remainder of the rap1b is incorporated more slowly. This biphasic incorporation of rap1b is similar to the incorporation of GPIIb/IIIa into the cytoskeleton, but no interaction between GPIIb/IIIa and rap1b could be demonstrated. Phosphorylation of rap1b by cAMP-dependent protein kinase did not inhibit its association with the cytoskeleton. We conclude that rap1b is one of an increasing number of proteins that associate with the cytoskeleton during cell activation. The function of rap1b in the cytoskeleton is unclear at this time. However, it is possible to speculate on potential roles. There is growing evidence that low molecular weight G proteins participate in the formation of multi-molecular aggregates. For example, p21rac promotes the assembly of a membrane-associated complex composed of NADPH oxidase, p47, and p67 and this complex is important for activation of NADPH oxidase in neutrophils. Similarly, in yeast, BUD1, a homolog of rap1, forms a complex with BUD5 (a homolog of GDI), BEMI, CDC24, and CDC42 (a homolog of G25K). This multi-protein aggregate may be important in cytoskeletal structure in yeast. In platelets, rad1b, which is membrane associated, may promote the assembly of a complex of proteins during cell activation and may localize this complex to the plasma membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Affinity chromatography of platelets on immobilized thrombin: retention of catalytic activity by platelet-bound thrombin

Radioactivity from I125-labeled human platelets was measured to estimate the extent of binding of platelet surface proteins to immobilized thrombin. 1-3% of the radioactivity was bound with 10-20% of this amount apparently irreversibly bound to the thrombin matrix. Site-specific chemical modification of thrombin with pyridoxal-5'-phosphate, N-bromosuccinimide or tetranitromethane resulted in a variable reduction of the amount of radiolabel bound. When thrombin modified with H-D-PheProArg-chloromethyl ketone (PPACK) was coupled to the matrix, there was no difference in the binding of platelet membrane proteins when compared to a control thrombin preparation while thrombin modified with tosyl-Lys-chloromethyl ketone (TLCK) coupled to the matrix did not bind radiolabel any more effectively than albumin which served as the control. However, when thrombin was modified with PPACK after coupling to the agarose matrix, ability to bind radiolabel was lost. Thrombin bound to platelets remained catalytically active when assayed with a peptide nitroanilide substrate. These results suggest tight binding between thrombin and platelets that is not only not dependent on active site integrity but leaves the bound thrombin catalytically competent.

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.

Purified factor IX using monoclonal immunoaffinity technique: clinical trials in hemophilia B and comparison to prothrombin complex concentrates

Replacement therapy for hemophilia B (factor IX deficiency) using prothrombin complex concentrate (PCC) has been associated with serious complications of thromboembolic events and transmission of viral infections. Monoclonal antibody-purified factor IX (Mononine) provides a highly purified factor IX concentrate, while eliminating other vitamin K-dependent factors (II, VII, and X). Mononine was evaluated for in vivo recovery, half-life, and for its safety and efficacy in 10 patients with hemophilia B. The in vivo recovery of factor IX with Mononine was a 0.67 +/- 0.14 U/dL (mean +/- SD) increase per 1U/kg of infused factor IX, and the biologic half-life (t1/2), determined using the terminal phase of elimination, was 22.6 +/- 8.1 hours. Comparison of in vivo recovery of other vitamin K-dependent factors following a single infusion of either Mononine or PCC showed that, whereas Mononine infusion caused no changes in other vitamin K-dependent factors or in prothrombin activation fragment (F1+2), PCC infusion was associated with significant increases of factors II (2.7 U/dL per 1 U/dL of IX increase) and X (2.2 U/dL for 1 U/dL for 1 U/dL of IX). Patients who used Mononine as their sole therapeutic material during the 12-month period showed an excellent response in hemostasis for their bleeding episodes. Their experience with long-term use of Mononine was at least equivalent to their previous experience with PCC in the frequency and amount of factor usage. No patients developed antibody against mouse IgG or an increase in IX inhibitor during the 12-month period. These results indicate that monoclonal antibody-purified factor IX concentrate provides hemostatically effective factor IX replacement while avoiding extraneous thrombogenic substances.

Nosocomial infection rate as a function of human immunodeficiency virus type 1 status in hemophiliacs

As part of a prospective cohort study initiated in 1983, the human immunodeficiency virus type 1 (HIV-1) status has been periodically determined for patients with clotting disorders (hemophilia A or B, von Willebrand's disease, miscellaneous). The University of North Carolina Hospitals has conducted comprehensive surveillance for nosocomial infections (NI) using modified Centers for Disease Control criteria since 1980 and entered this information in a computerized data base. Cross-matching of our NI data base and hemophiliac/HIV-1 study data base for the time period 1980-1989 revealed that 13 NI occurred in 11 patients during 659 hospitalizations (5,723 hospital days). NI rates per 100 admissions (per 1,000 hospital days) by HIV-1 status were as follows: HIV-1 negative = 0.91 (1.18), HIV-1 positive pre-AIDS = 1.65 (1.84), and AIDS = 6.67 (6.48). NI occurred with a similar frequency in HIV-1 positive pre-AIDS hemophiliacs and HIV-1 negative hemophiliacs (Fisher's exact test, p greater than 0.10). However, NI occurred more frequently in hemophiliacs with AIDS versus HIV-1 positive or negative hemophiliacs (Fisher's exact test, p less than 0.05). We conclude that HIV-1 infection does not appreciably alter the risk of developing a NI, but that patients who have progressed to AIDS are at significantly increased risk of developing a NI per hospital day or per hospitalization.

Hepatocellular carcinoma in hemophilia

A questionnaire-based survey involving 11,801 hemophiliacs from 54 hemophilia centers in the USA and Europe documented the occurrence of hepatocellular carcinoma (HCC) in 10 patients. The crude rate of HCC was 3.2/100,000 patients/year, at least 30 times higher than the background incidence of this tumor in the countries of origin of the patients. All patients were Caucasians with hemophilia A, 39 to 74 years of age, and had liver cirrhosis. All had one or more risk factor for cirrhosis and HCC: 5 were positive for serum hepatitis B surface antigen, 4 had the antibody to hepatitis C virus, and 4 had histories of alcohol abuse. Serum alpha-fetoprotein, measured in 6 patients, was significantly elevated in 4 (range: 807-1399 ng/ml), and only moderately elevated in 2 (25 and 171 ng/ml). The onset of HCC was asymptomatic in 5 patients, whereas it was accompanied by jaundice, abdominal pain, or ascites in the remaining patients. Thus, HCC seems to be a more important secondary disease for hemophiliacs than formerly recognized. Since HCC is often asymptomatic, screening hemophiliacs with chronic liver disease with periodic ultrasound scans might increase the changes of detecting HCC at a stage amenable to surgical treatment.

The localization of the cAMP-dependent protein kinase phosphorylation site in the platelet rat protein, rap 1B

Rap 1B is a low molecular weight G protein which is phosphorylated by cAMP-dependent protein kinase. In order to identify the site of phosphorylation by cAMP-dependent protein kinase, purified rap 1B from human platelets was phosphorylated and subjected to limited proteolysis with trypsin. Single digestion fragment containing the phosphorylation site was obtained and purified by reversed-phase HPLC. Sequence analysis of the phosphorylated digestion fragment demonstrated that the sequence of the phosphorylation site was -Lys-Lys-Ser-Ser-. This sequence is near the carboxy terminus and is adjacent to the site of membrane attachment of the protein.

Urinary cortisol and urea nitrogen responses in irreversibly undernourished mule deer fawns

We examined the concentration of urinary cortisol and urea nitrogen of five hand-reared mule deer (Odocoileus hemionus) fawns that failed to recover from winter starvation, and compared them to levels found in fawns that recovered. The fawns wintered in fenced pastures stocked with wild deer, and were put back on supplemental feed after losing 15% of their body mass. The five fawns that died began receiving supplemental feed up to 3 wk before death. All continued to lose weight, and were consequently removed from the pasture and fed ad libitum 4 to 10 days before death. In the animals that died, cortisol levels continued to increase regardless of food availability, and were correlated with those of urea nitrogen. Postmortem cortisol and urea nitrogen measurements were significantly greater than concentrations found in the weeks preceding death. We hypothesize that uncontrolled protein catabolism is promoted by high levels of cortisol. These cortisol levels may reach a point at which irreversible multiple-system organ failure occurs, leading to the animal's death.

rap1B, a cAMP-dependent protein kinase substrate, associates with the platelet cytoskeleton

rap1B is a member of the ras superfamily of low molecular weight GTP binding proteins which constitutes a focal point of GTP and cAMP signal transduction systems. Like other members of this superfamily, rap1B is membrane-associated in resting platelets, presumably through polyisoprenylation. The studies presented here were undertaken to determine the subcellular changes in rap1B localization during cell activation. Activated and unactivated platelets were fractionated by Triton X-100 lysis followed by differential centrifugation to obtain a 10,000 x g cytoskeleton fraction, a 100,000 x g membrane skeleton fraction, and a 100,000 x g supernatant fraction containing solubilized proteins. In unactivated platelets, rap1B was present in the 100,000 x g supernatant fraction. In contrast, in platelets activated with 1 unit/ml alpha-thrombin or with the calcium ionophore, A23187, rap1B was quantitatively recovered in the 10,000 x g cytoskeleton fraction. rap1B was absent from the 100,000 x g fraction containing the membrane skeleton and could not be detected in the 100,000 x g supernatant containing cytosolic proteins and solubilized membrane components. These results indicate that rap1B associates with the cytoskeleton during cell activation.

Human immunodeficiency virus-1 disease progression in hemophiliacs

A retrospective study of 153 hemophiliacs infected with human immunodeficiency virus-1 (HIV-1) was performed to determine the clinical and immunological consequences of HIV-1 infection and the markers and cofactors associated with these changes. Nearly 80% of HIV-1-infected hemophiliacs have developed a significant reduction in their CD-4+ counts (less than 400 CD-4+ cells/mm3) with 40% having less than 200 CD-4+ cells/mm3 by the end of 1987. The rate of CD-4+ cell count decline was slightly greater in patients who have already developed the acquired immunodeficiency syndrome (AIDS) compared to those who have not (50 vs. 31 cells/mm3/6 months). Thrombocytopenia and older age were associated with a more rapid CD-4+ count deterioration, but the quantity of clotting factor utilized did not affect immunologic progression. In patients with less than 200 CD-4+ cells/mm3, the incidence of AIDS was significantly higher in adults (greater than 21 years old) compared to children/adolescents. Cytomegalovirus (CMV) seroprevalence increased with age but did not correlate with the amount of concentrated clotting factor used. Although there was no relationship between CMV status and progression to AIDS, CMV-seropositive patients were older and had a lower CD-4+ count. Thus the majority of HIV-1-infected hemophiliacs are developing progressive immune dysfunction measured by CD-4+ count decline. This drop in CD-4+ count significantly correlates with a risk for the development of AIDS in adults but not in children (less than 21 years old).