SummaryTwo homozygous point mutations were found in a patient with factor X (FX) deficiency; One results in substitution of Lys for Gla+14 and the second causes a Lys substitution for Glu102. The proposita has a severely reduced FX coagulant activity in the extrinsic (<1% of normal) and in the intrinsic (30% of normal) system of coagulation and after activation with Russel’s viper venom (18% of normal). The FX antigen is reduced in this patient to 20% of normal. The substitution of Lys for Glu102 in FX deficiency has been reported previously in a heterozygous state in conjunction with a Lys for Gla+14 substitution and with a Pro for Ser334 substitution. The contribution of the Lys for Glu102 substitution in the observed combined FX defect in these patients was unclear. The mutation causing the Glu102Lys substitution was introduced by site directed mutagenesis into a wild-type FX cDNA, and recombinant protein was expressed in HEK 293 cells. Compared to the wild-type FX cDNA, the mutant construct had a 67% activity upon activation in the extrinsic system, 93% activity upon activation in the intrinsic system and 72% after activation with RVV. The data presented show that the substitution of Lys for Glu102 results in a minor functional defect of the FX molecule.

It has been proposed that interferon-gamma (IFN) inhibits collagen synthesis in myeloproliferative disorders through an inhibitory effect on PDGF and TGF-beta. We therefore evaluated the role of IFN-gamma on bone marrow fibrosis in idiopathic myelofibrosis (IMF). After a 3-month observation period, nine patients (five female, four male), median age 64 years (range 43-72 years), received 3 x 3 mU IFN-gamma/week over 6 months and were monitored after withdrawal of IFN-gamma for further 3 months. Three out of nine patients have completed the study according to the protocol. Six patients had to be withdrawn from IFN-gamma due to the following reasons: bacterial infection (three patients), splenic infarction or deterioration of splenomegaly (one patient, each) and refusal to continue IFN-gamma (one patient). Results from seven patients treated for at least 8 weeks were considered measurable. Leukopenia, initially present in one of the evaluated patients, deteriorated during IFN-gamma treatment. This patient died during the observation period shortly after withdrawal of the therapy as a result of septicemia. Transfusion-dependent anemia, initially observed in two of the evaluated patients, deteriorated during the IFN-gamma treatment. Bone marrow fibrosis increased in three patients, whereas it remained unchanged in another and improved in a further patient. Splenomegaly improved in two patients but deteriorated markedly in one. Taking these observations together, four patients had disease progression during IFN-gamma treatment, two had stable disease and one could be qualified as a partial responder. According to these data IFN-gamma cannot be considered as a treatment option for patients with IMF.

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It is known from large epidemiological studies that the elevation of coagulation factor VII in plasma is an independent risk factor for acute coronary syndromes. The level of factor VII is influenced by polymorphic sites in the factor VII gene. However, data on the association of such polymorphisms with the risk of acute coronary syndromes are conflicting. A decanucleotide insertion/deletion polymorphic site has been described in the promoter of the factor VII gene that leads to a dramatic change in the plasma factor VII levels. We therefore analyzed the association of this polymorphism with the risk of acute coronary syndromes in a case-control study. Included in the study were 111 patients with angiographically documented acute coronary syndromes and 108 age- and sex-matched individuals from the same geographic area without signs or symptoms of coronary heart disease. The presence or absence of the decanucleotide stretch at position -323 in the promoter of factor VII was monitored using a polymerase chain reaction (PCR)-based restriction technique. The prevalence of the genotype with the homozygous deletion was similar in the patients with acute coronary syndromes (79.2%) and in the control patients (79.6%). There was a non-significant trend toward a higher prevalence of the homozygote deletion in patients with premature acute coronary syndromes (77.4%) compared with an age-matched subgroup of the control patients (67. 5%) (odds ratio [OR] 1.6, confidence interval [CI] 0.95, 0.61-3.93). Thus, we could not find a significant association of the occurrence of acute coronary events with the insertion/deletion polymorphism in factor VII.