Low risk of transmission of the human immunodeficiency virus by a solvent-detergent-treated commercial factor VIII concentrate.

A study evaluating the risk of a commercial factor VIII (FVIII) concentrate's transmitting the human immunodeficiency virus (HIV) was carried out on hemophiliacs, by using multiple serological markers and the polymerase chain reaction (PCR). Twenty-nine hemophiliacs, negative for HIV antibodies, were treated for 18 months with a concentrate that had been inactivated by solvent-detergent. HIV-1 antibodies and antigen were assayed during the follow-up period. At the end of the study, all patients were also tested by the HIV 1 + 2 combined antibody assay; Western blot (WB) antibody analysis; and in eight cases, by an HIV-1 PCR technique. Patients received a yearly median FVIII dose of 35,330 IU (range 3,300-306,000); the median number of lots given to each patient was 6 (1-45). During the follow-up period and at the end of the study, HIV-1 antibodies and antigen were not detected in any of the subjects. The HIV 1 + 2 combined assay and WB analysis carried out only at the end of the study were negative. HIV-1 PCR was negative in all the tested patients. This study has shown that this solvent-detergent-treated FVIII concentrate did not transmit HIV.     

Safety of recombinant coagulation factors in treating hemophilia

Introduction: During the last decade, new FVIII/IX concentrates have been developed for the treatment of patients affected by hemophilia A/B. Significant progress has been achieved regarding their half-life, but the old issue of immunogenicity and new concerns about safety need to be addressed.

Areas covered: After the implementation of virucidal methods, both plasma-derived and recombinant clotting factor concentrates achieved a very safe profile. The development of anti-FVIII antibodies is the major adverse event of replacement therapy with both FVIII concentrates. Furthermore, the new extended half-life concentrates, protein fused or pegylated, raised some concerns about their side effects.

Expert Opinion: The treatment of hemophilia A with inhibitors by induction of immunotolerance and using by-passing concentrates, improved the quality of life of patients but did not allow them to have a life expectancy like that of patients without inhibitors. The new humanized monoclonal antibody (MAb) ACE910, mimicking FVIII function, seems to be able to reduce the bleedings of hemophilia A patients with inhibitors. The post-marketing surveillance will clarify if the adverse events observed during the phase III clinical trials and compassionate use were due to the association with a Prothrombin activated complex concentrate or to the prothrombotic effect of the drug itself.     

Management of inherited von Willebrand disease in Italy: results from the retrospective study on 1234 patients

Von Willebrand disease (VWD) is the most common inherited bleeding disorder and is due to quantitative and/or qualitative defects of von Willebrand factor (VWF). Despite the improved knowledge of the disease, detailed data on VWD types requiring specific treatments have not been reported thus far. To determine the number and types of VWD requiring therapy with desmopressin (DDAVP) and/or VWF/FVIII concentrates in Italy, a national registry on VWD (RENAWI) was organized. Only 16 of 48 centers included VWD in the RENAWI with diagnoses performed locally. Patients with uncertain results were retested by two expert laboratories using multimeric analysis and mutations of the VWF gene. A total of 1234 of 1529 (81%) cases satisfied the inclusion criteria and could be classified as VWD1 (63%), VWD2A (7%), VWD2B (6%), VWD2M (18%), VWD2N (1%), and VWD3 (5%). VWD types were also confirmed by DNA analyses and occur in young adults (83%), mainly in women (58%). Mucosal bleedings (32 to 57%) are more frequent than hematomas (13%) or hemarthrosis (6%). Most patients were exposed to an infusion trial with desmopressin (DDAVP) and found responsive with the following rates: VWD1 (69%), VWD2A (26%), VWD2M (29%), and VWD2N (71%). However, DDAVP was not always used to manage bleeding in all responsive patients and VWF/FVIII concentrates were given instead of or together with DDAVP in VWD1 (30%), VWD2A (84%), VWD2B (62%), VWD2M (63%), VWD2N (30%), and VWD3 (91%). Data of the RENAWI showed that correct VWD identification and classification might be difficult in many Italian centers. Therefore, evidence-based studies should be organized only in well-characterized patients tested by laboratories that are expert in the clinical, laboratory, and molecular markers of VWD.     

1-Methyl-4-phenylpyridinium affects fast axonal transport by activation of caspase and protein kinase C

Parkinson's disease (PD), a late-onset condition characterized by dysfunction and loss of dopaminergic neurons in the substantia nigra, has both sporadic and neurotoxic forms. Neurotoxins such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and its metabolite 1-methyl-4-phenylpyridinium (MPP+) induce PD symptoms and recapitulate major pathological hallmarks of PD in human and animal models. Both sporadic and MPP+-induced forms of PD proceed through a "dying-back" pattern of neuronal degeneration in affected neurons, characterized by early loss of synaptic terminals and axonopathy. However, axonal and synaptic-specific effects of MPP+ are poorly understood. Using isolated squid axoplasm, we show that MPP+ produces significant alterations in fast axonal transport (FAT) through activation of a caspase and a previously undescribed protein kinase C (PKCdelta) isoform. Specifically, MPP+ increased cytoplasmic dynein-dependent retrograde FAT and reduced kinesin-1-mediated anterograde FAT. Significantly, MPP+ effects were independent of both nuclear activities and ATP production. Consistent with its effects on FAT, MPP+ injection in presynaptic domains led to a dramatic reduction in the number of membranous profiles. Changes in availability of synaptic and neurotrophin-signaling components represent axonal and synaptic-specific effects of MPP+ that would produce a dying-back pathology. Our results identify a critical neuronal process affected by MPP+ and suggest that alterations in vesicle trafficking represent a primary event in PD pathogenesis. We propose that PD and other neurodegenerative diseases exhibiting dying-back neuropathology represent a previously undescribed category of neurological diseases characterized by dysfunction of vesicle transport and associated with the loss of synaptic function.     

The amino terminus of tau inhibits kinesin-dependent axonal transport: implications for filament toxicity

The neuropathology of Alzheimer's disease (AD) and other tauopathies is characterized by filamentous deposits of the microtubule-associated protein tau, but the relationship between tau polymerization and neurotoxicity is unknown. Here, we examined effects of filamentous tau on fast axonal transport (FAT) using isolated squid axoplasm. Monomeric and filamentous forms of recombinant human tau were perfused in axoplasm, and their effects on kinesin- and dynein-dependent FAT rates were evaluated by video microscopy. Although perfusion of monomeric tau at physiological concentrations showed no effect, tau filaments at the same concentrations selectively inhibited anterograde (kinesin-dependent) FAT, triggering the release of conventional kinesin from axoplasmic vesicles. Pharmacological experiments indicated that the effect of tau filaments on FAT is mediated by protein phosphatase 1 (PP1) and glycogen synthase kinase-3 (GSK-3) activities. Moreover, deletion analysis suggested that these effects depend on a conserved 18-amino-acid sequence at the amino terminus of tau. Interestingly, monomeric tau isoforms lacking the C-terminal half of the molecule (including the microtubule binding region) recapitulated the effects of full-length filamentous tau. Our results suggest that pathological tau aggregation contributes to neurodegeneration by altering a regulatory pathway for FAT.     

Axonal transport of APP and the spatial regulation of APP cleavage and function in neuronal cells

Over two decades have passed since the original discovery of amyloid precursor protein (APP). While physiological function(s) of APP still remain a matter of debate, consensus exists that the proteolytic processing of this protein represents a critical event in the life of neurons and that abnormalities in this process are instrumental in Alzheimer's disease (AD) pathogenesis. Specific molecular components involved in APP proteolysis have been identified, and their enzymatic activities characterized in great detail. As specific proteolytic fragments of APP are identified and novel physiological effects for these fragments are revealed, more obvious becomes our need to understand the spatial organization of APP proteolysis. Valuable insights on this process have been obtained through the study of non-neuronal cells. However, much less is known about the topology of APP processing in neuronal cells, which are characterized by their remarkably complex cellular architecture and extreme degree of polarization. In this review, we discuss published literature addressing various molecular mechanisms and components involved in the trafficking and subcellular distribution of APP and APP secretases in neurons. These include the relevant machinery involved in their sorting, the identity of membranous organelles in which APP is transported, and the molecular motor-based mechanisms involved in their translocation. We also review experimental evidence specifically addressing the processing of APP at the axonal compartment. Understanding neuron-specific mechanisms of APP processing would help illuminating the physiological roles of APP-derived proteolytic fragments and provide novel insights on AD pathogenesis.     

Phosphorylation in the amino terminus of tau prevents inhibition of anterograde axonal transport

Alzheimer's disease (AD) and other tauopathies are characterized by fibrillar inclusions composed of the microtubule-associated protein, tau. Recently, we demonstrated that the N-terminus of tau (amino acids [aa] 2-18) in filamentous aggregates or N-terminal tau isoforms activate a signaling cascade involving protein phosphatase 1 and glycogen synthase kinase 3 that results in inhibition of anterograde fast axonal transport (FAT). We have termed the functional motif comprised of aa 2-18 in tau the phosphatase-activating domain (PAD). Here, we show that phosphorylation of tau at tyrosine 18, which is a fyn phosphorylation site within PAD, prevents inhibition of anterograde FAT induced by both filamentous tau and 6D tau. Moreover, Fyn-mediated phosphorylation of tyrosine 18 is reduced in disease-associated forms of tau (e.g., tau filaments). A novel PAD-specific monoclonal antibody revealed that exposure of PAD in tau occurs before and more frequently than tyrosine 18 phosphorylation in the evolution of tangle formation in AD. These results indicate that N-terminal phosphorylation may constitute a regulatory mechanism that controls tau-mediated inhibition of anterograde FAT in AD.     

Knowledge of HIV/AIDS and emotional adjustment in a cohort of men with haemophilia and HIV infection: final report

This study presents the final report of a long-term psychological assessment of men with haemophilia and HIV infection. The knowledge, emotional impact regarding HIV infection and prospective changes over time and the need for psychological support were evaluated. The study group comprised 118 men with haemophilia, 66 HIV seropositive and 52 seronegative, from the Haemophilia Centres in Bari, Florence, Milan and Naples. All subjects performed psychological tests (STAI: state and trait anxiety inventory; SDS: self-rating depression scale) and completed questionnaires to ascertain their knowledge and the emotional impact of AIDS. After enrollment (1992-93) the assessment was repeated twice over a 2-year period. A high percentage of subjects in both groups answered the questionnaire on knowledge correctly and, more specifically, all (100%) admitted knowing that sexual intercourse was a risk factor for HIV infection, adding that sexual partners of haemophiliacs with HIV should be regularly tested. The percentage, however, decreased for seropositives who admitted to always using a condom during sexual intercourse (86%) and for those who declared that partners were periodically tested for HIV (60%). The most important feature of the study is that, contrary to predicted expectations, seropositive and seronegative subjects presented the same degree of emotional involvement: there are no statistically significant differences in average scores between groups either on the anxiety or depression scales. Moreover, for certain aspects, seronegatives revealed greater emotional involvement: at baseline evaluation, they felt more fear and unhappiness with statistically significant differences compared to asymptomatics. Furthermore, seronegatives more than seropositives continue to feel reluctance towards infusion and avoid blood products after learning of AIDS. These results emphasize the importance of paying due attention to the emotional status of seronegatives. Their reluctance towards the use of blood products (despite present safety) is a very important issue for the possible consequences of treatment with the risk of worsening the clinical condition. In conclusion, we believe that counselling on HIV infection/AIDS needs to address every person with haemophilia regardless of HIV status.     

Multivariate analysis of factors influencing quality of life and utility in patients with haemophilia.

BACKGROUND AND OBJECTIVES: Although several studies have determined quality of life (QOL) in patients with hemophilia, generic questionnaires have rarely been used. The objectives of our study were; 1) to measure QOL and utility in patients with hemophilia using the Short Form 36 (SF-36) and the EuroQOL questionnaires; 2) to evaluate the influence of some clinical variables on QOL and utility; 3) to assess the correlation between the two questionnaires. DESIGN AND METHODS: All consecutive patients with hemophilia were asked to complete the SF-36 and the EuroQOL questionnaires. The following information was recorded from each patient: age, type of hemophilia, severity of disease, HCV and HIV infection, number of bleeding episodes and cumulative dose of coagulation factors over the previous year. These items were entered into a multivariate analysis to assess their effect on QOL. Correlation analyses were conducted to evaluate the relationship between the EuroQOL and SF-36. RESULTS: Fifty-six patients completed the SF-36 and the EuroQOL questionnaires. The mean scores of the SF-36 ranged from 55.2 (general health) to 74.7 (social functioning). The EuroQOLself-classifier and the EuroQOLvas showed a mean score of 0.67 (SD=0.26) and 0.66 (SD=0.17), respectively. Among the clinical variables, age significantly influenced both the EuroQOL and the SF-36 scores. The EuroQOL indices showed a statistically significant correlation with each dimension of the SF-36. INTERPRETATION AND CONCLUSIONS: Our study quantified the degree to which QOL is impaired in patients with hemophilia by using both a generic questionnaire and a utility-based approach.