Successful immune tolerance induction with a plasma-derived FVIII concentrate and intravenous immunoglobulins in a pediatric patient with congenital severe hemophilia A and poor prognostic factors.

We present the case of a pediatric patient born in July 1991, diagnosed with severe hemophilia A at 8 months of life after a hemarthrosis. He was treated with regular factor replacement therapy on-demand until an inhibitor was detected (1.75-2.5 BU) at the age of 6. The patient started an immunotolerance induction (ITI) program, which was discontinued 3 months later because of parental decision based on inhibitor persistence (3.75-6.75 BU). On-demand treatment with recombinant activated FVII in bleeding episodes was applied. Titer peaked 13 months later (37 BU). On May 2003 (age 11), rescue ITI with plasma-derived FVIII (Fanhdi, 100 IU/kg per 24 h daily) and intravenous immunoglobulin (IVIg) (Flebogamma, 1 g/kg per 24 h for 2 days every 3 weeks) was started. Inhibitor eradication was achieved after 16 months of ITI. The patient continued with FVIII+IVIg treatment for 3 additional months when he was switched to FVIII prophylaxis (40 IU/kg 3 times a week). At present, the patient is inhibitor-free.

Organellar proteomics of human platelet dense granules reveals that 14-3-3zeta is a granule protein related to atherosclerosis.

Dense granules, a type of platelet secretory organelle, are known to accumulate high concentrations of small molecules such as calcium, adenine nucleotides, serotonin, pyrophosphate, and polyphosphate. Protein composition of these granules has been obscure, however. In this paper, we use proteomics techniques to describe, for the first time, the soluble protein composition of platelet dense granules. We have isolated highly enriched human platelet dense granule fractions that have been analyzed using two proteomics methods. Using this approach, we have identified 40 proteins, and most of them, such as actin-associated proteins, glycolytic enzymes, and regulatory proteins, have not previously been related to the organelle. We have focused our efforts on studying 14-3-3zeta, a member of a conserved family of proteins that interact with hundreds of different proteins. We have demonstrated that 14-3-3zeta is localized mostly on dense granules and that it is secreted after platelet activation. As some proteins secreted from activated platelets could promote the development of atherosclerosis and thrombosis, we have studied the expression of 14-3-3zeta in sections of human abdominal aorta of patients with aneurysm, identifying it at the atherosclerotic plaques. Together, our results reveal new details of the composition of the platelet dense granule and suggest an extracellular function for 14-3-3zeta associated with atherosclerosis.

Antiphospholipid syndrome and asymptomatic carriers of antiphospholipid antibody: prospective analysis of 404 individuals.

OBJECTIVE: We carried out a prospective analysis of clinical and analytical findings in individuals with antiphospholipid antibodies (aPL). METHODS: We prospectively studied 404 individuals, classified in 2 groups: (1) patients with primary or secondary antiphospholipid syndrome (APS, n = 226); and (2) asymptomatic carriers of aPL (n = 178). Patients with APS and thrombosis were treated with dicumarin, and an international normalized ratio around 3.0 (range 2.5-3.5) was targeted. Asymptomatic carriers were not treated, but specific prophylaxis with low molecular weight heparin or aspirin was prescribed for the periods when individuals were at increased risk of thrombosis. Both groups of individuals were followed up at semester intervals for 36 months. RESULTS: Patients with APS presented with venous (n = 106, 46.9%) and/or arterial (n = 70. 31%) thrombosis or fetal loss (n = 58 out of 112 women of fertility age, 51.8%). At the time of the first thrombotic event, 50.0% of patients with APS had coincident risk factors for thrombosis (previous surgery and prolonged immobilization were significantly associated with venous thrombosis, and hypercholesterolemia and arterial hypertension with arterial thrombosis). Eighteen patients with APS died during the study period. Recurrence of thrombosis in patients with APS was linked to insufficient anticoagulation. During the followup, no episode of thrombosis was detected in any asymptomatic carrier. The proportion of subjects with aPL was similar in patients and in asymptomatic carriers. The proportion of subjects with aPL decreased during the followup, in both patients and carriers. CONCLUSION: Differences between patients and asymptomatic carriers with aPL are at least partially dependent on the proportion of coincident vascular risk factors. The decline in aPL during the followup defines a subgroup in which an anticoagulation suppression assay could be tried.