Recurrent leg ulcers and arterial thrombosis in a 33-year-old homozygous variant of antithrombin

Antithrombin Deficiency Is Associated with a Novel Homozygous Detrimental Mutation in SERPINC1 Gene in a Saudi Female

Antithrombin (AT) deficiency is a blood disorder associated with an increased tendency to form thrombosis. Hereditary AT deficiency is frequently caused by mutations in SERPINC1 gene. It is usually inherited as an autosomal dominant with variable penetrance. Homozygous pathogenic mutations in this gene are extremely rare. We present a case of a 7-year-old female who presented at age of 4 years with massive cerebral sinus venous thrombosis. Thrombophilia workup showed a low AT level of 30%. Targeted genetic sequencing of SERPINC1 revealed a novel pathogenic homozygous mutation c.1320C>G p. (Phe440Leu). The patient was managed initially with unfractionated heparin with AT replacement using fresh frozen plasma and was later switched to only low-molecular-weight heparin. There was no recurrence or new thrombosis with 3 years of follow-up.

Age and Origin of the Founder Antithrombin Budapest 3 (p.Leu131Phe) Mutation; Its High Prevalence in the Roma Population and Its Association With Cardiovascular Diseases

Background: Antithrombin (AT) is one of the most important regulator of hemostasis. AT Budapest 3 (ATBp3) is a prevalent type II heparin-binding site (IIHBS) deficiency due to founder effect. Thrombosis is a complex disease including arterial (ATE) and venous thrombotic events (VTE) and the Roma population, the largest ethnic minority in Europe has increased susceptibility to these diseases partly due to their unfavorable genetic load. We aimed to calculate the age and origin of ATBp3 and to explore whether the frequency of it is higher in the Roma population as compared with the general population from the corresponding geographical area. We investigated the association of ATBp3 with thrombotic events in well-defined patients' populations in order to refine the recommendation when testing for ATBp3 is useful.

Methods and Results: Prevalence of ATBp3, investigated in large samples (n = 1,000 and 1,185 for general Hungarian and Roma populations, respectively) was considerably high, almost 3%, among Roma and the founder effect was confirmed in their samples, while it was absent in the Hungarian general population. Age of ATBp3—as calculated by analysis of 8 short tandem repeat sequences surrounding SERPINC1—was dated back to XVII Century, when Roma migration in Central and Eastern Europe occurred. In our IIHBS cohort (n = 230), VTE was registered in almost all ATBp3 homozygotes (93%) and in 44% of heterozygotes. ATE occurred with lower frequency in ATBp3 (around 6%); it was rather associated with AT Basel (44%). All patients with ATE were young at the time of diagnosis. Upon investigating consecutive young (<40 years) patients with ATE (n = 92) and VTE (n = 110), the presence of ATBp3 was remarkable.

Conclusions: ATBp3, a 400-year-old founder mutation is prevalent in Roma population and its Roma origin can reasonably be assumed. By the demonstration of the presence of ATBp3 in ATE patients, we draw the attention to consider type IIHBS AT deficiency in the background of not only VTE but also ATE, especially in selected populations as young patients without advanced atherosclerosis. We recommend including the investigation of ATBp3 as part of thrombosis risk assessment and stratification in Roma individuals.

Bilateral renal artery thrombosis in inherited thrombophilia: a rare cause of acute kidney injury

We describe the case of a 47-year-old man who developed significant acute, and subsequently chronic, kidney injury due to bilateral renal infarction. This occurred in the context of a combined inherited thrombophilia including antithrombin III deficiency and a prothrombin gene mutation. Bilateral renal artery thrombosis developed despite prophylactic treatment for thromboembolism. Arterial thrombosis is rare in the context of inherited thrombophilia and bilateral renal infarction is an unusual cause of acute kidney injury. Bilateral renal infarction due to primary renal artery thrombosis has not been previously described in antithrombin III deficiency, either as an isolated defect or in combination with other hereditary thrombophilia.

Impact of the type of SERPINC1 mutation and subtype of antithrombin deficiency on the thrombotic phenotype in hereditary antithrombin deficiency

Mutations in the antithrombin (AT) gene can impair the capacity of AT to bind heparin (AT deficiency type IIHBS), its target proteases such as thrombin (type IIRS), or both (type IIPE). Type II AT deficiencies are almost exclusively caused by missense mutations, whereas type I AT deficiency can originate from missense or null mutations. In a retrospective cohort study, we investigated the impact of the type of mutation and type of AT deficiency on the manifestation of thromboembolic events in 377 patients with hereditary AT deficiencies (133 from our own cohort, 244 reported in the literature). Carriers of missense mutations showed a lower risk of venous thromboembolism (VTE) than those of null mutations (adjusted hazard ratio [HR] 0.39, 95% confidence interval [CI] 0.27-0.58, p<0.001), and the risk of VTE was significantly decreased among patients with type IIHBS AT deficiency compared to patients with other types of AT deficiency (HR 0.23, 95%CI 0.13-0.41, p<0.001). The risk of pulmonary embolism complicating deep-vein thrombosis was lower in all type II AT deficiencies compared to type I AT deficiency (relative risk 0.69, 95%CI 0.56-0.84). By contrast, the risk of arterial thromboembolism tended to be higher in carriers of missense mutations than in those with null mutations (HR 6.08-fold, 95%CI 0.74-49.81, p=0.093) and was 5.9-fold increased (95%CI 1.22-28.62, p=0.028) in type IIHBS versus other types of AT deficiency. Our data indicate that the type of inherited AT defect modulates not only the risk of thromboembolism but also the localisation and encourage further studies to unravel this phenomenon.

Déficit homozygote en antithrombine de type HBS; à propos d'une famille

Congenital antithrombin (AT) deficiency is the most thrombotic genetic abnormality of haemostasis. Total quantitative deficits are lethal as early as life intra-uterine. Only homozygous mutations concerning the heparin-binding site are compatible with life. We report here the case of an 18 years old patient with recurrent deep venous thrombosis of the inferior members. Haemostasis exploration shows a decreased AT activity (11%) in the presence of heparin while AT progressive activity and AT antigen are normal. Two other homozygous sisters are identified in this family study. Molecular study of AT gene show Arg47-Cys substitution, already reported in the literature with patients of different geographic origins. Treatment of patients with homozygous AT type HBS deficiency is similar that for patients with heterozygous AT deficiency; a continuous prophylactic anticoagulant treatment is always necessary and AT concentrates infusions are required in all situations needing curative heparin treatment.

Lipodermatosclerosis as a form of vascular compromise-associated radiation recall dermatitis: case report and a review of literature

Lipodermatosclerosis (LDS) is a prototypic ischemic dermopathy that is most commonly associated with venous insufficiency. There have been no prior reports describing LDS as a form of radiation recall dermatitis (RRD). We present a case of a 47-year-old female affected by squamous cell carcinoma of the anus who underwent irradiation and subsequent chemotherapy with 5-fluorouracil and cisplatin. She then developed tender, erythematous, indurated plaques on skin of the buttocks, corresponding closely to one of the previous radiotherapy fields. As histopathological studies were compatible with LDS and the skin eruption coincided with drug intake 3 months after radiotherapy, the diagnosis of RRD with LDS features was rendered. This is the first case providing evidence of the causative role of 5-fluorouracil and cisplatin in potentially inducing RRD.

Increased incidence of hypercoagulability in patients with leg ulcers caused by leukocytoclastic vasculitis

Vasculitis is a rare cause of leg ulceration. It is unclear why severe skin infarction develops in some patients with vasculitis, whereas others have only mild symptoms such as purpura, erythema, or urticaria. A coincidence of vasculitis and hypercoagulability may lead to more extensive thrombotic occlusion and hence explain the occurrence of large ulcers in a subset of patients. Our aim was to investigate whether patients with vasculitis ulcers have an increased incidence of hypercoagulability. Thirteen consecutive patients admitted to the hospital with necrotic ulcers caused by histologically confirmed vasculitis were screened for clotting disorders. In 7 of 13 patients (53%), hypercoagulable conditions were found. Five patients had factor V Leiden (38%), and 2 had lupus anticoagulant (15%). The normal frequency of these conditions is 5% to 6% and 3.6%, respectively. These data indicate that there is an increased incidence of hypercoagulable disorders in patients with vasculitis ulcers. We recommend screening these patients routinely for hypercoagulability.