No abstract

Although up to 50% of all haemophilic patients followed at haemophilia treatment centres (HTCs) are affected by a mild factor VIII (FVIII) or factor IX (FIX) defect, published data regarding the natural history of these disorders are scarce. To fill this lack of information, a retrospective single centre study was conducted. All cases with mild haemophilia (75 A and 7 B) followed at the regional reference HTC of Parma were evaluated. The patients' median age at diagnosis was 11.5 years and their median age at first bleeding was 5.5 years; 95% of patients had a history of haemorrhagic problems during their life. Twenty-three percent of patients were infected by HCV, and none by HIV. Genetic analysis was performed in 80 patients (97% haemophilia A and 100% haemophilia B) and 21 different mutations were characterized. Eleven percent of patients had never received treatment, whereas 67% were treated with plasma-derived or recombinant FVIII/FIX concentrates (4% developed inhibitors). desmopressin (DDAVP) was used in 80% of the haemophilia A patients. The response to DDAVP was closely related to the patients' genetic profile, as 60% of non-responders had a mutation in the F8 promoter region. Patients with mild haemophilia may experience a variety of medical problems, sometimes challenging for the physicians, during their lifetime. The HTCs play an important role in the management of these patients, whose diagnosis is often delayed. The HTCs should improve patients' knowledge and consideration of their disease and encourage them to maintain regular contact with their haemophilia care provider.

Congenital factor VII (FVII) deficiency is a rare bleeding disorder caused by mutations in F7 gene with autosomal recessive inheritance. A clinical heterogeneity with poor correlation with FVII:C levels has been described. It was the objective of this study to identify genetic defects and to evaluate their relationships with phenotype in a large cohort of patients with FVII:C<50 %. One hundred twenty-three probands were genotyped for F7 mutations and three polymorphic variants and classified according to recently published clinical scores. Forty out of 123 patients (33 %) were symptomatic (43 bleedings). A severe bleeding tendency was observed only in patients with FVII:C<0.10 %. Epistaxis (11 %) and menorrhagia (32 % of females in fertile age) were the most frequent bleedings. Molecular analysis detected 48 mutations, 20 not reported in the F7 international databases. Most mutations (62 %) were missense, large deletions were 6.2 %. Compound heterozygotes/homozygotes for mutations presented lower FVII:C levels compared to the other classes (Chi=43.709, p<0,001). The polymorphisms distribution was significantly different among the three F7 genotypic groups (Chi=72.289, p<0,001). The presence of truncating mutations was associated with lowest FVII:C levels (Chi=21.351, p=0.002). This study confirms the clinical and molecular variability of the disease and the type of symptoms. It shows a good correlation between the type of F7 mutation and/or polymorphisms and FVII:C levels, without a direct link between FVII:C and bleeding tendency. The results suggest that large deletions are underestimated and that they represent a common mechanism of F7 gene inactivation which should always be investigated in the diagnostic testing for FVII deficiency.

Although desmopressin (DDAVP) is considered as the treatment of choice for many patients with mild hemophilia A, several aspects of DDAVP therapy remain unclear, including the rate and type of response and the molecular determinants of its clinical efficacy. To investigate these issues, we retrospectively studied all patients with mild hemophilia A followed up at the Parma Hemophilia Center. A total of 75 patients were enrolled who underwent a DDAVP test, and out of whom, 76% (57/75) had a complete or partial response. Response to DDAVP was significantly correlated to the patients' age (median age of responders and nonresponders: 24 and 18 y, respectively; p = 0.04) and type of mutation (all the 10 patients with mutations in the promoter region were nonresponders). The median basal factor VIII (FVIII):C level was significantly lower in responders than in nonresponders (0.14 vs. 0.19 IU/mL, respectively; p = 0.01); this was mainly due to nonresponders with promoter region mutations who had higher basal FVIII:C levels. During the 12-year follow-up, 82 of 237 (35%) bleeding episodes occurring in 27 responder patients were treated with 246 DDAVP infusions with complete or partial efficacy in 92% (75/82). Overall, 142 events were managed with 253 prophylactic DDAVP infusions, which were hemostatically effective in 96% of cases. No severe adverse reactions to DDAVP administration were recorded during the study period. These results document the safety and efficacy of DDAVP as a treatment or prevention of bleeding in patients with mild hemophilia A, also in the context of home treatment, and encourage the more widespread use of this product.