Diagnostic issues faced by a rare disease healthcare network during Covid-19 outbreak: data from the Campania Rare Disease Registry

Background

The aims of this study were: to investigate the capacity of the rare disease healthcare network in Campania to diagnose patients with rare diseases during the outbreak of Covid-19; and to shed light on problematic diagnoses during this period.

Methods

To describe the impact of the Covid-19 pandemic on the diagnosis of patients with rare diseases, a retrospective analysis of the Campania Region Rare Disease Registry was performed. A tailored questionnaire was sent to rare disease experts to investigate major issues during the emergency period.

Results

Prevalence of new diagnoses of rare disease in March and April 2020 was significantly lower than in 2019 (117 versus 317, P < 0.001 and 37 versus 349, P < 0.001, respectively) and 2018 (117 versus 389, P < 0.001 and 37 versus 282, P < 0.001, respectively). Eighty-two among 98 rare disease experts completed the questionnaire. Diagnostic success (95%), access to diagnosis (80%) and follow-up (72%), lack of Personal Protective Equipment (60%), lack of Covid-19 guidelines (50%) and the need for home therapy (78%) were the most important issues raised during Covid-19 outbreak.

Conclusions

This study describes the effects of the Covid-19 outbreak on the diagnosis of rare disease in a single Italian region and investigates potential issues of diagnosis and management during this period.

The HLA Variant rs6903608 Is Associated with Disease Onset and Relapse of Immune-Mediated Thrombotic Thrombocytopenic Purpura in Caucasians

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare, life-threatening thrombotic microangiopathy caused by severe ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motifs 13) deficiency, recurring in 30–50% of patients. The common human leukocyte antigen (HLA) variant rs6903608 was found to be associated with prevalent iTTP, but whether this variant is associated with disease relapse is unknown. To estimate the impact of rs6903608 on iTTP onset and relapse, we performed a case-control and cohort study in 161 Italian patients with a first iTTP episode between 2002 and 2018, and in 456 Italian controls. Variation in rs6903608 was strongly associated with iTTP onset (homozygotes odds ratio (OR) 4.68 (95% confidence interval (CI) 2.67 to 8.23); heterozygotes OR 1.64 (95%CI 0.95 to 2.83)), which occurred over three years earlier for each extra risk allele (β −3.34, 95%CI −6.69 to 0.02). Of 153 survivors (median follow-up 4.9 years (95%CI 3.7 to 6.1)), 44 (29%) relapsed. The risk allele homozygotes had a 46% (95%CI 36 to 57%) absolute risk of relapse by year 6, which was significantly higher than both heterozygotes (22% (95%CI 16 to 29%)) and reference allele homozygotes (30% (95%CI 23 to 39%)). In conclusion, HLA variant rs6903608 is a risk factor for both iTTP onset and relapse. This newly identified biomarker may help with recognizing patients at high risk of relapse, who would benefit from close monitoring or intensified immunosuppressive therapy.

Left ventricular diastolic abnormalities other than valvular heart disease in antiphospholipid syndrome: An echocardiographic study

BACKGROUND

Antiphospholipid syndrome (APS) can be primary or secondary to other autoimmune disorders. Besides valvular heart disease (VHD) and coronary artery disease (CAD), little is known about the impact of APS on left ventricular (LV) function.

METHODS

After excluding CAD, relevant VHD and heart failure, 69 patients (mean age = 43.9 years, 40 with primary and 29 with secondary APS) were assessed by echo-Doppler. Sixty-nine heathy controls, matched for age and sex, formed the control group. APS was diagnosed in presence of at least one clinical criteria and one confirmed laboratory criteria, including lupus anticoagulant (LA) titre. The adjusted global APS score (aGAPSS), derived from the combination of risk factors for thrombosis and autoimmune-antibody profile was calculated.

RESULTS

Patients had similar blood pressure and heart rate, but higher body mass index (BMI) than controls. LV mass index (p = 0.007) and left atrial volume index (p < 0.01) were greater, while early diastolic velocity (e') was lower (p = 0.003) and E/e' higher (p = 0.007) in APS. Primary APS patients had lower E/A and e' compared to both controls and secondary APS, while E/e' was higher in secondary APS than in controls. APS patients with diastolic dysfunction were older but did not differ for risk factors prevalence from those with normal/indeterminate diastolic function. In the pooled APS, LA positivity was independently associated with e' and E/e' after adjusting for age, BMI and aGAPSS in separate multivariate models.

CONCLUSION

In APS, LV diastolic abnormalities are detectable. They are more pronounced in primary APS and independently associated with LA positivity.

Persistent Impairment of Platelet Aggregation following Cessation of a Short-course Dietary Supplementation of Moderate Amounts of N-3 Fatty Acid Ethyl Esters

The duration of the effect of a short-course (1-mo twice-daily) supplementation of moderate amounts (2.28 g) of n-3 fatty acid ethyl esters (FA) on platelet lipid composition and aggregation was compared with that of olive oil (3 g/d) supplementation in 14 healthy volunteers. The FA preparation employed contained eicosapentaenoic acid (EPA) and docosahexaenoic acids (DHA) in a ratio of 1:1.4. A marked rise (p <0.05) in the plasma and platelet content of EPA and DHA, and minimal changes in the content of arachidonic acid (AA) were documented at withdrawal of the n-3 FA supplementation. EPA/AA and DHA/AA ratios in platelet phospholipids showed that the FA accumulation persisted 8-12 wks after stopping the supplementation (p <0.05). The aggregation of platelets in response to collagen or ADP, and thromboxane B2 (TXB2) formation were impaired at withdrawal. The impaired aggregation lasted 8-12 weeks (p always <0.05), whereas TXB2 formation returned to basal values 4 weeks after stopping the n-3 supplementation. No correlation was found between impaired aggregation and TXB2 formation. In contrast, the impaired sensitivity to ADP (p = 0.036) and, to a lesser extent, to collagen (p = 0.068) were related to changes in the intracellular pH (pHi) of the Na+/H+ reverse transport. No changes in platelet composition or function were observed either during or following olive oil supplementation. These results document a long-lasting impairment of platelet sensitivity to ADP and collagen; changes in the pHi values of the Na+/H+ reverse transport, and a simultaneous persistent accumulation of EPA and DHA in platelet phospholipids, after stopping a short-course dietary supplementation of moderate amounts of n-3 fatty acid ethyl esters.

Inferior Vena Cava Agenesis and Deep Vein Thrombosis in the Young: A Review of the Literature and Local Experience

Congenital agenesis of the inferior vena cava (AIVC) is a rare vascular abnormality with a prevalence of 0.0005 to 1% in the general population. This condition is found in almost 5% of young patients (younger than 30 years) with proximal, typically bilateral, deep venous thrombosis (DVT) of the lower limbs, often in the absence of apparent risk factors. However, AIVC in young patients with DVT is probably underestimated because AIVC cannot be detected by the standard DVT diagnostic workup. Inherited thrombophilia has been reported in patients with AIVC-associated DVT, as an additional risk factor, but its role is poorly investigated. The best therapeutic strategy and the optimal duration of anticoagulant treatment of DVT in patients with AIVC are still unclear. Here, we describe 14 young patients (2 females and 12 males, mean age at first DVT: 27.8 ± 10.1 years), with color Doppler ultrasound (US) and abdominal computed tomography scan confirmed AIVC-associated DVT and discuss their characteristics in the framework of a literature review on this topic. Our patients were mainly males (10/12) and experienced proximal DVT events, not complicated by pulmonary embolism. DVT-precipitating factors were detected only in five cases, the two female patients (oral contraceptives and puerperium), and three male patients (one after leg fracture and two after abdominal surgery). Thrombophilic abnormalities were found in eight patients (heterozygous factor V Leiden mutation, n = 3; mild/moderate hyperhomocysteinemia, n = 3; reduced protein C activity, n = 1; antiphospholipid syndrome, n = 1). The majority of patients (13/14) were treated with long-term oral anticoagulant therapy and elastic stockings (ES), with a very low rate of DVT recurrence (1/14, mean follow-up 7 years). These clinical characteristics were largely consistent with those of 161 patients identified by review of the literature. On the whole, although many aspects are still poorly known, our case series and literature review suggest that a search should be undertaken for AIVC in young patients with proximal idiopathic, particularly when bilateral, DVT, which should then be treated with prolonged anticoagulation and ES.

Preventing Venous Thromboembolism in Ambulatory Cancer Patients: The ONKOTEV Study

BACKGROUND

The efficacy of risk model scores to predict venous thromboembolism (VTE) in ambulatory cancer patients is under investigation, aiming to stratify on an individual risk basis the subset of the cancer population that could mostly benefit from primary thromboprophylaxis.

MATERIALS AND METHODS

We prospectively assessed 843 patients with active cancers, collecting clinical and laboratory data. We screened all the patients with a duplex ultrasound (B-mode imaging and Doppler waveform analysis) of the upper and lower limbs to evaluate the right incidence of VTE (both asymptomatic and symptomatic). The efficacy of the existing Khorana risk model in preventing VTE was also explored in our population. Several risk factors associated with VTE were analyzed, leading to the construction of a risk model. The Fine and Gray model was used to account for death as a competing risk in the derivation of the new model.

RESULTS

The risk factors significantly associated with VTE at univariate analysis and further confirmed in the multivariate analysis, after bootstrap validation, were the presence of metastatic disease, the compression of vascular/lymphatic structures by tumor, a history of previous VTE, and a Khorana score >2. Time-dependent receiving operating characteristic (ROC) curve analysis showed a significant improvement in the area under the curve of the new score over the Khorana model at 3 months (71.9% vs. 57.9%, p = .001), 6 months (75.4% vs. 58.6%, p < .001), and 12 months (69.8% vs. 58.3%, p = .014).

CONCLUSION

ONKOTEV score steps into history of cancer-related-VTE as a promising tool to drive the decision about primary prophylaxis in cancer outpatients. The validation represents the goal of the prospective ONKOTEV-2 study, endorsed and approved by the European Organization for Research and Treatment of Cancer Young Investigators Program. The Oncologist 2017;22:601-608 IMPLICATIONS FOR PRACTICE: Preventing venous thromboembolism in cancer outpatients with a risk model score will drive physicians' decision of starting thromboprophylaxis in high-risk patients.

Pharmacological treatment and prevention of chronic venous ulcers: a review

Chronic venous insufficiency and chronic venous ulcers represent an important medical problem, because of the high incidence and prevalence in the general population, and need to be considered as a lifelong degenerative condition, with socioeconomic consequences. Ulceration is a severe complication of the post-thrombotic syndrome, often precipitated by minor trauma. The rate of post-thrombotic syndrome varies between 20% and 100% of patients with deep vein thrombosis, mostly occurring within two years of an initial thrombotic event. This syndrome is difficult to treat, causes significant disability and reduces the quality of life. To date, there are no effective therapies of chronic venous ulcers and no definite strategies for identifying patients at risk for the development of ulceration. The role of adequate compression with elastic stockings is well recognized. Several systemic drugs have been tested for a possible effect on chronic venous ulcer healing, but none has been widely accepted as standard therapy in this setting. It has been suggested that extended oral anticoagulation should be investigated as a possible preventative measure. Waiting for the results in this field, an adequate management of anticoagulation in terms of anticoagulant intensity and duration should be recommended for the prevention of recurrent deep vein thrombosis, post-thrombotic syndrome and chronic venous ulcers.

Noninvasive assessment of liver fibrosis in patients with chronic hepatitis C (and congenital bleeding disorders): where do we stand?

The assessment and monitoring of liver fibrosis (LF) is a key issue in the management and definition of prognosis of patients with chronic hepatitis C (CHC). In this respect, despite recognized limitations (invasive nature, sampling errors, interobserver variability, nondynamic evaluation of LF), liver biopsy is traditionally considered the reference standard. These limitations stimulated the search for noninvasive approaches for the assessment of LF, particularly attractive in patients with hemophilia and other congenital bleeding disorders (CBD). In patients with congenital bleeding disorders (CBD), who often suffer from CHC because of the past use of nonvirally inactivated plasma-derived products, the risk of bleeding hamper to routinely obtain histological data for LF staging. A variety of methods have been proposed and, in some cases, validated in patients with CHC and other liver diseases, including biomarkers directly or indirectly associated with LF, often combined in scores or algorithms, and the more recently developed physical approaches, evaluating the properties of the liver parenchyma with instrumental techniques studying the propagation of specific signals, that is, transient elastography (TE), acoustic radiation force impulse imaging elastography, and magnetic resonance elastography. This review will describe the available strategies for noninvasive assessment of LF, with more details on the latter promising instrumental approaches. Moreover, although lacking of validation against liver biopsy, recent studies extending the use of noninvasive methods (particularly TE) in the setting of patients with CBD will be discussed.

Acquired inhibitors of coagulation factors: part I-acquired hemophilia A

Acquired hemophilia A (AHA) is a rare, but often severe, bleeding disorder caused by autoantibodies against clotting factor VIII (FVIII). AHA occurs more frequently in the elderly and in association with several conditions, such as malignancies, autoimmune diseases, postpartum, or drug exposure; however, about half of the cases remain idiopathic. At variance with congenital hemophilia, where hemarthroses are the most common bleeding symptoms, hemorrhages in AHA involving soft tissues (muscle, skin) are more frequently reported. AHA is diagnosed in patients: with negative personal or family bleeding history; in which prolonged activated partial thromboplastin time is not corrected after mixing and incubating equal volumes of patient and normal plasma for ~2 hours at 37°C; FVIII levels are reduced; and a specific FVIII-inhibiting activity is detected. Prompt recognition and treatment of AHA are mandatory, as inadequate management and complications of the disease are associated with high mortality rates. Therapeutic approaches should aim to control acute bleeds, eradicate FVIII-autoantibody production, treat associated diseases, and when possible, eliminate them. Present knowledge about this often overlooked and challenging condition has significantly increased following establishment of recent national and international studies, as will also be reviewed in this article.

Molecular analysis and genotype-phenotype correlation in patients with antithrombin deficiency from Southern Italy

We sequenced the SERPINC1 gene in 26 patients (11 males) with antithrombin (AT) deficiency (22 type I, 4 type II), belonging to 18 unrelated families from Southern Italy. Heterozygous mutations were identified in 15/18 (83.3%) families. Of them, eight were novel mutations, each being identified in one family. Seven clearly cause impaired protein synthesis (four frameshift, one non-stop, one splicing and one 21bp deletion). One, present in a single patient, is a missense mutation thought to be causative because: a) it is absent in 100 chromosomes from controls; b) it involves a highly conserved amino acid, whose change is predicted to impair AT activity; c) no other mutation is present in the propositus. Severe mutations (i.e. nonsense, frameshift, deletions) were invariably identified in type I patients. In type II patients, 3/4 were missense mutations; the fourth leads to a 19 nucleotides shift in the stop codon. In addition to the type of mutation, the co-existence of other predisposing factors in most patients helps explain the severity of the present type I cases (age at first event, recurrence during prophylaxis). In the five families in which there was more than one member affected, the same genotype and a concordant clinical expression of the disease were found. We conclude that the molecular bases of AT deficiency in Southern Italy are different as compared to other geographic areas, and that molecular analysis and the study of the effect of the mutation may help predict the clinical expression of the disease.

Coronary artery disease, cerebral non-fatal ischemic stroke in retinal vein occlusion: an 8-yr follow-up

Forty-five consecutive subjects (26M, 19F; mean age 54 ± 14 yrs) with a diagnosed retinal vein occlusion (RVO), were followed-up for 8 yrs. As many as 145 sex-age- and blood pressure-matched individuals (78M, 67F; mean age 54.4 ± 13.5 yrs), that did not experience any vascular event, served as controls. At the time of the RVO, controls and subjects did not differ as to hypercholesterolemia, hypertrigliceridemia, diabetes mellitus, smoking habits, inherited/acquired thrombophilia. At the follow-up completion, they differed as to statin consumption (p = 0.016). During the 8-yrs follow-up, in the control population, 11 out of 145 (7.6%) subjects had experienced a major vascular event (8 coronary artery disease; 3 cerebral non-fatal ischemic stroke). In contrast, of the 45 subjects with a history of RVO, as many as 10 (22.2%) had experienced a major vascular event: 4 coronary artery disease; 4 cerebral non-fatal ischemic stroke; 2 cardiovascular + cerebrovascular event (p = 0.012). A prolonged antiplatelet treatment, prior to the major vascular event, was found in 5/45 cases (11.1%) vs 23/145 (15.9%) controls (p = 0.63). In contrast, a long-lasting administration of anti-hypertensive drugs, to achieve a control of blood pressure, was found in 83.4% of controls and only in 46.7% of cases (p < 0.0001). In conclusion, in a 8-yr follow-up, coronary artery disease and/or non-fatal ischemic stroke were more common in subjects with a history of RVO than in a large setting of subjects comparable for cardiovascular risk factors. These data also argue for RVO as a vascular disease in which aggressive anti-hypertensive therapy to prevent stroke and/or myocardial infarction is needed.

The challenge of diagnosing pulmonary embolism in children, pregnant women, and elderly patients: a descriptive review of the literature

The prompt and accurate diagnosis of pulmonary embolism (PE) greatly influences patient outcomes. However, diagnosing PE is one of the most difficult challenges confronting physicians, even more so when the clinical suspicion is addressed in children, during pregnancy, or in elderly patients. In these patient groups, symptoms and signs from concomitant conditions or diseases may mimic PE and make difficult defining clinical probability categories for PE as usually applied to general adult patients. Moreover, the diagnostic techniques show wider, specific limitations in these settings. PE is considered rare in children. The diagnostic management of a child with suspected PE is largely extrapolated from the knowledge achieved in adult patients. An increased risk of venous thromboembolism is reported in all trimesters of pregnancy and in the puerperium. An accurate diagnosis of PE in pregnancy has important implications, including the need for prolonged anticoagulation, delivery planning, and prophylaxis during future pregnancies, as well as concerns about future oral contraceptive use and estrogen therapy. Although incidence, morbidity, and mortality increase steadily with age, PE remains an underdiagnosed disease in elderly patients. About 40% of PE found at necropsy were not suspected antemortem. In the present article, challenges in diagnosing PE in children, during pregnancy, and in the elderly will be discussed, reviewing the available clinical, laboratory, and instrumental diagnostic strategies.

Preventing postsurgical venous thromboembolism: pharmacological approaches

The use of antithrombotic drugs for the prevention of venous thromboembolism (VTE) in patients undergoing surgery is presently based on solid principles and high-level scientific evidence. This article reviews current strategies of pharmacological thromboprophylaxis. The level of VTE risk following surgery depends on a variety of factors that the surgeon should take into account, including the type of surgery and the presence of additional risk factors, such as elderly age and cancer. In patients undergoing minor general surgery, early mobilization is sufficient as prophylaxis, whereas in those undergoing major general surgery, thromboprophylaxis with low molecular weight heparin (LMWH), low-dose unfractionated heparin, or the pentasaccharide fondaparinux is recommended. Patients undergoing major orthopedic surgery have a particularly high risk of VTE, and routine thromboprophylaxis with LMWH, fondaparinux, or a vitamin K antagonist (international normalized ratio target: 2.0 to 3.0) is the standard of care in this group of patients. Recently, two new oral anticoagulants, rivaroxaban (a factor Xa inhibitor) and dabigatran etexilate (a direct thrombin inhibitor) have been licensed to be used for thromboprophylaxis after orthopedic surgery in Europe. Mechanical methods of thromboprophylaxis (compression stockings, intermittent pneumatic compression, vena cava filters), not discussed in detail in this review, should always be considered in patients at high thrombotic risk, in association with the pharmacological strategies, or in cases of contraindications to anticoagulants, as in patients or procedures at high risk of bleeding.

Abnormally high prevalence of major components of the metabolic syndrome in subjects with early-onset idiopathic venous thromboembolism

BACKGROUND

Although patients with idiopathic VTE are at higher than normal risk of asymptomatic atherosclerosis and of cardiovascular events, the impact of cardiovascular risk factors on VTE is poorly understood.

OBJECTIVE

To assess the prevalence of the metabolic syndrome and of its components in patients with early-onset idiopathic VTE.

METHODS

As many as 323 patients referred to our Thrombosis Ward for a recent (<6-months) early-onset idiopathic venous thromboembolism (VTE), were compared with 868 gender- and age-matched subjects, in whom a history of venous thrombosis had been excluded, referred during the same period time to our Ward. All had undergone a clinical assessment for smoking habits and for the presence of the components of the metabolic syndrome.

RESULTS

The metabolic syndrome was detected in 76/323 cases (23.5%) and in 81/868 controls (9.3%) (p<0.001; OR:2.990; 95%C.I.:2.119-4.217). Smoking was more common in patients with idiopathic VTE than in controls. In addition to the metabolic syndrome as a whole, its major individual determinants (arterial hypertension, impaired fasting glucose plasma levels, abdominal obesity, hypertriglyceridemia, low HDL-cholesterol) significantly correlated with idiopathic VTE (p always <0.05). The prevalence of thrombotic events was lower in females than in males (p=0.000; OR:2.217), the latter being most often hypertensives, smokers, hypertriglyceridemics, carriers of a metabolic syndrome and of impaired fasting glucose than females. In a multivariate analysis, arterial hypertension, impaired fasting glucose, abdominal obesity, and hypercholesterolemia independently predicted idiopathic venous events.

CONCLUSIONS

Both metabolic syndrome as a whole and its major components individually considered, independently predict early-onset idiopathic VTE.

Treatment of hemophilia: a review of current advances and ongoing issues

Replacement of the congenitally deficient factor VIII or IX through plasma-derived or recombinant concentrates is the mainstay of treatment for hemophilia. Concentrate infusions when hemorrhages occur typically in joint and muscles (on-demand treatment) is able to resolve bleeding, but does not prevent the progressive joint deterioration leading to crippling hemophilic arthropathy. Therefore, primary prophylaxis, ie, regular infusion of concentrates started after the first joint bleed and/or before the age of two years, is now recognized as first-line treatment in children with severe hemophilia. Secondary prophylaxis, whenever started, aims to avoid (or delay) the progression of arthropathy and improve patient quality of life. Interestingly, recent data suggest a role for early prophylaxis also in preventing development of inhibitors, the most serious complication of treatment in hemophilia, in which multiple genetic and environmental factors may be involved. Treatment of bleeds in patients with inhibitors requires bypassing agents (activated prothrombin complex concentrates, recombinant factor VIIa). However, eradication of inhibitors by induction of immune tolerance should be the first choice for patients with recent onset inhibitors. The wide availability of safe factor concentrates and programs for comprehensive care has now resulted in highly satisfactory treatment of hemophilia patients in developed countries. Unfortunately, this is not true for more than two-thirds of persons with hemophilia, who live in developing countries.

Longer-acting factor VIII to overcome limitations in haemophilia management: the PEGylated liposomes formulation issue

Injected factor VIII (FVIII), the current treatment for haemophilia A, leads to major improvements in the quality of life and life expectancy of individuals with this disorder. However, because injected FVIII has a short half-life in vivo, this strategy has major limitations for highly demanding regimens (e.g. prophylaxis, immune tolerance induction, surgery). Newer formulations of longer-acting FVIII are presently under investigation. The use of low molecular weight polyethylene glycol (PEG)-containing liposomes as carriers for recombinant FVIII (rFVIII) results in the prolongation of haemostatic efficacy. Data from preclinical experiments in mice, early clinical evaluations, and pharmacokinetics and pharmacodynamics results indicate that an rFVIII pegylated liposomal formulation may provide potential clinical benefit to patients with severe haemophilia A by prolonging the protection from bleeding. In light of this potential clinical benefit, a multicentre, randomized, active-controlled, non-inferiority phase II trial with two parallel treatment arms and equal randomization after stratification for the presence or absence of target joints in patients and for ages >/=18 years vs. <18 years is currently being conducted. The study will test the hypothesis that rFVIII-Lip once-weekly prophylaxis is not inferior to rFVIII-water for injection thrice-weekly prophylaxis. A total of 250 patients will be enrolled with severe haemophilia A (<1% FVIII) on on-demand or secondary prophylaxis treatment and with documented bleeds or injections during the 6 months before study entry. Sixty-four centres in 14 different countries are involved in the study; recruitment is underway. In Italy, six centres have already included 15 patients (no screening failure). Eight of these patients have completed the run-in phase and have begun the home treatment. No unexpected serious adverse events have been reported thus far. Data emerging from this phase II study will help collect relevant data to overcome current limitations in haemophilia management by employing treatment with longer-acting rFVIII.

Cardiovascular events in patients with antiphospholipid antibodies: strategies of prevention

Antiphospholipid antibodies are a heterogeneous group of auto-antibodies against phospholipids-binding proteins. The antiphospholipid syndrome is an autoimmune disorder characterized by the clinical association of antiphospholipid antibodies with a condition of hypercoagulability that can affect any blood vessel. Involvement of larger vessels, such as arteries or veins, manifests in the form of thrombosis or thromboembolism, whereas involvement of small vessels manifests as thrombotic micro-angiopathy. The antiphospholipid syndrome is also characterized by the presence of recurrent fetal loss. Patients who are persistently positive for antiphospholipid tests, and who have an arterial thrombosis or venous thrombosis history, are at increased risk of recurrence. Oral anticoagulant therapy is the mainstay of treatment for the thrombotic manifestations of the syndrome. Therapy with anticoagulant drugs should be long-term. On the other hand, although the thromboembolic potential of antiphospholipid antibodies has been well documented, there is still no general consensus on the prophylactic treatment of antiphospholipid antibodies carriers who have never developed vascular/obstetric manifestations. The effect of primary prophylaxis in antiphospholipid antibodies positive individuals is not well known and no evidence-based recommendations exist for thrombosis prevention in these individuals. However, the presence of risk factors for thrombosis increases the risk of first event of antiphospholipid antibodies positive patients. In conclusion, there is still much to learn on primary prophylaxis of asymptomatic antiphospholipid antibodies carriers. Hopefully, evidence-based guidelines will be available in the future.

Diabetes, vascular complications and antiplatelet therapy: open problems

Diabetes mellitus is commonly associated with both microvascular and macrovascular complications (coronary artery disease, cerebrovascular events, severe peripheral vascular disease, nephropathy and retinopathy). There is wide evidence demonstrating that platelet degranulation and synthesis of TxA2 are increased in diabetic patients. For this reason, many studies on anti-platelet therapy have been made to reduce thrombotic complication of diabetes mellitus. Some diabetic patients, although treated with ASA, have a high prevalence of recurrent thrombotic events, which may presumably be due to an "ASA resistance". Nevertheless, this drug remains the one with the greatest benefit. To optimize its function, we should try to understand the causes of "aspirin resistance", try to find the most suitable dosage, recommending patients to comply constantly with the prescription given and to avoid interactions with other drugs. "Clopidogrel resistance" is a term not clearly defined. The clinical implications of "clopidogrel resistance" are unknown. An important consideration affecting the use of aspirin in diabetic patients is its interaction with ACE-inhibitors. Another question is antiplatelet therapy in nephropathic diabetic patients. Although these patients are at high thrombotic and haemorrhagic risk, they should nevertheless be considered eligible to undergo antithrombotic therapy, taking into account the individual's haemorrhagic risk.

Cost of care of haemophilia with inhibitors

In Western countries, the treatment of patients with inhibitors is presently the most challenging and serious issue in haemophilia management, direct costs of clotting factor concentrates accounting for >98% of the highest economic burden absorbed for the healthcare of patients in this setting. Being designed to address questions of resource allocation and effectiveness, decision models are the golden standard to reliably assess the overall economic implications of haemophilia with inhibitors in terms of mortality, bleeding-related morbidity, and severity of arthropathy. However, presently, most data analyses stem from retrospective short-term evaluations, that only allow for the analysis of direct health costs. In the setting of chronic diseases, the cost-utility analysis, that takes into account the beneficial effects of a given treatment/healthcare intervention in terms of health-related quality of life, is likely to be the most appropriate approach. To calculate net benefits, the quality adjusted life year, that significantly reflects such health gain, has to be compared with specific economic impacts. Differences in data sources, in medical practice and/or in healthcare systems and costs, imply that most current pharmacoeconomic analyses are confined to a narrow healthcare payer perspective. Long-term/lifetime prospective or observational studies, devoted to a careful definition of when to start a treatment; of regimens (dose and type of product) to employ, and of inhibitor population (children/adults, low-responding/high responding inhibitors) to study, are thus urgently needed to allow for newer insights, based on reliable data sources into resource allocation, effectiveness and cost-utility analysis in the treatment of haemophiliacs with inhibitors.

Long-term prophylaxis with intermediate-purity factor VIII concentrate (Haemate P) in a patient with type 3 von Willebrand disease and recurrent gastrointestinal bleeding

Prophylaxis with von Willebrand factor (VWF)-containing concentrates is considered to be a potential approach for patients with von Willebrand disease (VWD) and severe bleeding tendency. We report the case of a 57-year-old man with type 3 VWD and a history of recurrent melaena. Bleeding frequency and severity had progressively increased and the patient showed chronic anaemia and persistent haemoglobin in the stools. Endoscopic examinations revealed multiple vascular mucosal abnormalities (MVA) of the stomach and large bowel. Photocoagulation of some actively bleeding lesions and octreotide did not significantly affect his clinical conditions: six red cell transfusions and >400 000 IU of intermediate-purity factor VIII (FVIII) concentrate (Haemate P) on-demand were needed during 2002. Prophylaxis with Haemate P 40 IU kg(-1) (102 IU kg(-1) VWF:RCo) thrice weekly was associated with improvement of his mean haemoglobin levels, cessation of clear-cut melaena and red cell transfusions and reduction of total Haemate P requirements (-20% over 2003-04). Prophylaxis with Haemate P is still ongoing without any adverse event over a 30-month period. Clinical course and pharmacokinetic evaluations led to administer Haemate P each 72-96 h. Possible vascular complications were excluded by a careful clinical follow up, as the patient suffered from arterial hypertension and diabetes mellitus; thrombophilic abnormalities were previously excluded and no signs of abnormal coagulation activation or FVIII:C levels >150% were detected thereafter. Long-term prophylaxis with Haemate P has been shown to be safe, effective (also in terms of quality of life) and cost saving in this patient with severe gastrointestinal bleeding due to MVA and VWD.

Long-lasting intestinal bleeding in an old patient with multiple mucosal vascular abnormalities and Glanzmann's thrombasthenia: 3-year pharmacological management

A 75-year-old woman with Glanzmann's thrombasthenia was admitted because of persistent melaena. Endoscopic examination showed multiple angiodysplastic lesions, with active bleeding in small and large bowel. Electro-coagulation of some lesions, octreotide, conjugated oestrogens and selective embolization of jejunal vessels did not change transfusion requirements. After 8 month-transfusions, ethinylestradiol + norethisterone in association with octreotide was started, leading to no transfusion over the following 9 months. Bleeding recurred after withdrawing octreotide and substituting ethinylestradiol + norgestrel for the ethinylestradiol + norethisterone combination. Re-introduction of octreotide did not improve bleeding; however, a reduction of transfusion requirement was observed when the ethinylestradiol + norethisterone pill was re-administered. The association of octreotide and of an oestrogen-progesterone combination was helpful in the difficult management of recurrent bleeding in this patient with diffuse gastrointestinal vascular abnormalities and a severe condition predisposing to bleeding.

The use of antithrombotic drugs in older people

Older individuals (subjects aged >65 years) largely contribute to the percentage deaths due to myocardial infarction (MI) and stroke. The incidence of venous thromboembolism (VTE) is also higher >65 years old patients. However, the risk of bleeding complications in patients on antithrombotic drugs increases with age and with clinical conditions, as cognitive/psychiatric diseases, traumas, hypertension, poor compliance with medications, common in the elderly. Thus the risk-benefit ratio of antithrombotics should be carefully evaluated in older individuals. To prevent the risk and the recurrence of ischemic stroke and MI in the older patients with stable/ unstable angina, MI, TIA/stroke or peripheral arterial disease, antiplatelet drugs are of choice. Aspirin is the most widely used antiplatelet drug. Clopidogrel is safer and more effective than aspirin in this respect. The combination of heparin and aspirin is the treatment of choice for unstable angina and non-Q wave MI, also in the elderly. Low molecular weight heparins (LMWHs) proved to be as effective as standard heparin in this indication. In the absence of contraindications, thrombolysis for treatment of acute MI may be considered in the elderly. For the treatment of acute venous thromboembolism (VTE), intravenous standard heparin, subcutaneous standard heparin or LMWHs are effective. Because of the limited risk/benefit ratio, thrombolytic agents are not recommended for treating deep vein thrombosis (DVT) in the elderly. They should be limited to young patients and to patients with massive pulmonary embolism (PE). For chronic treatment of VTE, warfarin is the treatment of choice (INR 2.0-3.0), also in the elderly. Because of hypersensitivity to oral anticoagulants, lower dosages of warfarin are needed in the old patient. As to prophylaxis of VTE in surgery, in subjects at low-moderate risk, or in medical patients, low-dose heparin or low-dose LMWHs are effective. As to prophylaxis of VTE in surgery in subjects at high risk, adjusted-dose heparin or high-dose LMWHs are recommended. Finally, as to prevention of stroke in patients older than 75 with atrial fibrillation (AF), warfarin is of choice.

Hyperhomocysteinemia and other inherited prothrombotic conditions in young adults with a history of ischemic stroke

BACKGROUND AND PURPOSE

The mechanisms of ischemic stroke in young adults are poorly understood. During the last years, several studies suggested a role for genetic factors predisposing to thrombophilia and for moderate hyperhomocysteinemia in this setting.

METHODS

We evaluated in 132 consecutive patients (66 males, 66 females; mean+/-SD age, 38.4+/-11.7 years; mean+/-SD age at first event, 34.8+/-10.9 years; range, 6 months to 50 years) referred to our center between January 1997 and December 1999 for a history of young adult ischemic stroke (age at first event, <51 years) the prevalence of factor V (FV) Leiden, prothrombin (FII) G20210A, and C677T and 5,10-methylenetetrahydrofolate reductase (MTHFR) gene mutations and fasting serum total homocysteine levels. Two hundred sixty-two apparently healthy subjects (117 males, 145 females; mean+/-SD age, 36+/-13.2 years) served as controls.

RESULTS

Total homocysteine levels differed significantly (P=0.004, t test) between patients and controls: 13.03+/-18.61 versus 10.75+/-6.24 micromol/L (mean+/-SD), respectively. In contrast, homozygosity for the TT mutation of the MTHFR gene was 30 of 132 (22.7%) in patients and 45 of 262 (17.2%) in controls; this difference was not statistically significant (P>0.05, chi(2) test). However, when we stratified the whole population according to genotype, fasting serum homocysteine levels were significantly higher in TT patients than in TT controls (25.3+/-36.8 versus 15+/-11.6 micromol/L; P=0.02, t test). Mutations of FV Leiden and of FII G20210A gene are currently reported to be associated with a tendency toward ischemic stroke. Their frequencies were not statistically significantly different between patients and controls in this setting: 7 of 132 (5.3%) versus 17 of 262 (6.5%) for FV Leiden and 10 of 132 (7.6%) versus 16 of 262 (6.1%) for FII G20210A, respectively (all P>0.05, chi(2) test).

CONCLUSIONS

In the present cohort of patients, moderate hyperhomocysteinemia is the only variable that helps to identify young adults with a history of ischemic stroke.

Oxidative stress and platelet activation in homozygous homocystinuria

BACKGROUND

Severe hyperhomocysteinemia due to cystathionine beta-synthase deficiency (CbetaSD) is associated with early atherothrombotic vascular disease. Homocysteine may exert its effects by promoting oxidative damage. In the present study, we investigated whether in vivo formation of 8-iso-prostaglandin (PG) F(2alpha), a platelet-active product of arachidonic acid peroxidation, is enhanced in CbetaSD and whether it correlates with in vivo platelet activation, as reflected by thromboxane (TX) metabolite excretion.

METHODS AND RESULTS

Urine and blood samples were obtained from patients with homozygous CbetaSD (n=13) and age-matched healthy subjects. Urinary 8-iso-PGF(2alpha) excretion was significantly higher in CbetaSD patients than in control subjects (640+/-384 versus 213+/-43 pg/mg creatinine; P=0.0015) and correlated with plasma homocysteine (rho=0.398, P=0.0076). Similarly, urinary 11-dehydro-TXB(2) excretion was enhanced in CbetaSD (1166+/-415 versus 324+/-72 pg/mg creatinine; P=0.0015) and correlated with urinary 8-iso-PGF(2alpha) (rho=0.362, P=0.0153). Vitamin E supplementation (600 mg/d for 2 weeks) was associated with a statistically significant increase in its plasma levels (from 16.6+/-4.6 to 40.4+/-8.7 micromol/L, P=0.0002) and with reductions in 8-iso-PGF(2alpha) (from 790+/-159 to 559+/-111 pg/mg creatinine, P=0.018) and 11-dehydro-TXB(2) (from 1273+/-383 to 913+/-336 pg/mg creatinine, P=0.028). A statistically significant inverse correlation was found between urinary 8-iso-PGF(2alpha) and plasma vitamin E levels (rho=-0.745, P=0.0135).

CONCLUSIONS

The results of the present study suggest that enhanced peroxidation of arachidonic acid to form bioactive F(2)-isoprostanes may represent an important mechanism linking hyperhomocysteinemia and platelet activation in CbetaSD patients. Moreover, they provide a rationale for dose-finding studies of vitamin E supplementation in this setting.

Homocysteine, coagulation, platelet function, and thrombosis

Over the last 30 years, a growing body of evidence has documented the role of hyperhomocysteinemia (HHcy) as an independent vascular risk factor. However, the mechanisms through which elevated circulating levels of homocysteine (Hcy) cause vascular injury and promote thrombosis remain elusive. Most findings have been achieved in in vitro studies employing exceedingly high concentrations of Hcy, whereas only a few studies have been carried out in vivo in humans. In homocystinuric patients, homozygotes for mutations of the gene coding for the cystathionine beta-synthase enzyme, abnormalities of coagulation variables reflecting a hypercoagulable state, have been reported. In vitro studies provide a biochemical background for such a state. In homocystinuric patients, an in vivo platelet activation has also been reported. The latter abnormality is not corrected by the bolus infusion of concentrations of hirudin, which determines a long-lasting impairment of the conversion of fibrinogen to fibrin by thrombin; in contrast, it appears at least in part lowered by the administration of the antioxidant drug probucol. During the autooxidation of Hcy in plasma, reactive oxygen species are generated. The latter initiate lipid peroxidation in cell membranes (potentially responsible for endothelial dysfunction) and in circulating lipoproteins. Oxidized low-density lipoproteins (LDL) may trigger platelet activation as well as some of the hemostatic abnormalities reported in such patients. Thus the oxidative stress induced by Hcy may be a key process in the pathogenesis of thrombosis in HHcy. Accumulation of adenosylhomocysteine in cells (a consequence of high circulating levels of homocysteine) inhibits methyltransferase enzymes, in turn preventing repair of aged or damaged cells. This mechanism has been recently documented in patients with renal failure and HHcy and provides an additional direction to be followed to understand the tendency to thrombosis in moderate HHcy.

Antithrombotic drugs for older subjects. Guidelines formulated jointly by the Italian Societies of Haemostasis and Thrombosis (SISET) and of Gerontology and Geriatrics (SIGG)

Older individuals contribute heavily to the percentage of deaths due to myocardial infarction (MI) and stroke. The incidence of venous thromboembolism (VTE) is highest in subjects > 65 years. Prospective intervention trials involving groups of clinically comparable subjects > or = 60 allow the following statements to be made with regard to the use of antithrombotic drugs in the elderly. Antiplatelet agents. To prevent recurrence of ischaemic stroke and MI in stable/unstable angina, MI, TIA/stroke or peripheral arterial disease, aspirin is the drug of choice. Clopidogrel is more effective than aspirin in this respect. Heparin. For the treatment of acute deep venous thrombosis (DVT) and pulmonary embolism (PE), intravenous standard heparin or subcutaneous standard heparin are effective (aPTT 1.5-2.0 times baseline values). As the risk of bleeding increases with age, low-molecular-weight heparins (LMWH) are preferable in the elderly. For the prophylaxis of VTE in general surgery in subjects at low-moderate risk, low-dose heparin or low doses of LMWH are effective. In subjects at high risk, adjusted-dose heparin plus physical devices or high-dose LMWH are recommended. The combination of heparin and aspirin is the standard treatment for unstable angina and non-Q wave MI. LMWH are as active as standard heparin in this indication. Vitamin K antagonists. For the chronic treatment of VTE, warfarin is also the treatment of choice (INR 2.0-3.0) in the elderly, though lower doses are needed due to their hypersensitivity to oral anticoagulants. For the prevention of thromboembolic stroke in patients > 75 with atrial fibrillation, warfarin is the drug of choice. Patients aged 65-75 may receive warfarin or aspirin. Thrombolytic agents. Thrombolytic agents are not recommended for treating DVT in the elderly because of their limited risk/benefit ratio and should be confined to massive PE. In the absence of contraindications, thrombolysis for MI may be considered in the elderly.

The role of vitamin B12 in fasting hyperhomocysteinemia and its interaction with the homozygous C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. A case-control study of patients with early-onset thrombotic events

Total fasting plasma homocysteine (tHcy), homozygosity for the C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene and for the A2756G mutation of the methionine synthase (MS) gene, vitamin B12 and folate plasma levels were evaluated in 170 consecutive patients (89 M, 81 F; mean age 41 +/- 12 yrs) with documented early-onset thrombosis (89 venous, 69 arterial, 12 both; mean age at first episode 36 +/- 11 yrs), and in 182 age- and sex-matched healthy control subjects. Moderate hyperhomocysteinemia (HHcy, tHcy >19.5 microM in men and >15 microM in women) was detected in 45 patients (26.5%) and in 18 controls (9.9%, Mantel-Haenszel OR and 95% C.I. after stratification for arterial or venous thrombosis: 3.25, 1.78-5.91). The 677TT MTHFR genotype was not significantly more prevalent in patients (27.6%) than in controls (21.4%, RR = 1.42: 0.84-2.41), and markedly contributed to HHcy (Mantel-Haenszel RR after stratification for case/control status: 8.29, 4.61-14.9). The 2756GG MS genotype, observed in 4 patients (2.4%) and 8 controls (4.4%), was not associated to HHcy. tHcy was negatively correlated to folate and vitamin B12 levels, with better correlation found in subjects with the 677TT mutation (r = -0.42 and -0.25) than with the 677CC or CT MTHFR genotype (r = 0).37 and -0.11). However, folate was similar in patients and controls and vitamin B12 was higher in patients (460 +/- 206 vs. 408 +/-185 pg/ml, p = 0.011). In a generalized linear model, 44% of the variation in tHcy levels was explained by folate and vitamin B12 levels, the MTHFR genotype, gender, and by the interaction of the MTHFR genotype with folate (p < or =0.028); the interactions of vitamin B12 with the MTHFR genotype, gender and patient/control status also significantly contributed to the variation in tHcy levels (p < or =0.028). A 4-week administration of 5-methyltetrahydrofolate (15 mg/day) markedly lowered plasma tHcy in 24 patients with MTHFR 677TT genotype, but the response to treatment correlated with vitamin B,2 levels (p = 0.023). Subjects carrying the MTHFR 677TT genotype have higher folate and vitamin B12 requirements irrespective of the A2756G polymorphism of the MS gene. Yet unidentified abnormalities of MS or of any of the enzymes participating in the synthesis of methylated vitamin B12 may play an important role in the phenotypic expression of moderate hyperhomocysteinemia.

Nutrition and thrombogenic factors

In the 80's, three retrospective studies showed an inverse relation between fish consumption and ischemic heart disease (IHD) mortality. In parallel, fish fats containing the polyunsaturated fatty acid eicosapentaenoic (EPA) were shown to impair platelet aggregation and thromboxane formation. The results of the large prospective Diet and Reinfarction (DART) Study in the secondary prevention of myocardial infarction have further supported the possibility of potential interrelationships between diet and thrombogenic factors with respect to IHD. More recently these concepts have been confirmed and extended in the prospective Lyon Heart Study. However, in the latter in addition to changes in the content of EPA, changes in other well known variables (i.e. leukocytes and vitamin E) often abnormal in subjects prone to arterial thrombosis have been found. From studies on polygenic disorders, we have learned that by lowering the threshold and becoming a susceptibility gene, a polymorphism can lead to an effect assuming that it is present in the appropriate milieu. Nutrients have been shown to affect major determinants of myocardial ischemia such as fibrinogen or factor VII. However, the extent to what these and other hemostatic variables have been affected in studies devoted to dietary prevention of ischemia remains presently elusive.

Persistent impairment of platelet aggregation following cessation of a short-course dietary supplementation of moderate amounts of N-3 fatty acid ethyl esters

The duration of the effect of a short-course (1-mo twice-daily) supplementation of moderate amounts (2.28 g) of n-3 fatty acid ethyl esters (FA) on platelet lipid composition and aggregation was compared with that of olive oil (3 g/d) supplementation in 14 healthy volunteers. The FA preparation employed contained eicosapentaenoic acid (EPA) and docosahexaenoic acids (DHA) in a ratio of 1:1.4. A marked rise (p <0.05) in the plasma and platelet content of EPA and DHA, and minimal changes in the content of arachidonic acid (AA) were documented at withdrawal of the n-3 FA supplementation. EPA/AA and DHA/AA ratios in platelet phospholipids showed that the FA accumulation persisted 8-12 wks after stopping the supplementation (p <0.05). The aggregation of platelets in response to collagen or ADP, and thromboxane B2 (TXB2) formation were impaired at withdrawal. The impaired aggregation lasted 8-12 weeks (p always <0.05), whereas TXB2 formation returned to basal values 4 weeks after stopping the n-3 supplementation. No correlation was found between impaired aggregation and TXB2 formation. In contrast, the impaired sensitivity to ADP (p = 0.036) and, to a lesser extent, to collagen (p = 0.068) were related to changes in the intracellular pH (pHi) of the Na+/H+ reverse transport. No changes in platelet composition or function were observed either during or following olive oil supplementation. These results document a long-lasting impairment of platelet sensitivity to ADP and collagen; changes in the pHi values of the Na+/H+ reverse transport, and a simultaneous persistent accumulation of EPA and DHA in platelet phospholipids, after stopping a short-course dietary supplementation of moderate amounts of n-3 fatty acid ethyl esters.

Platelet and monocyte variables in homocystinuria due to cystathionine-beta-synthase deficiency

To gain insight into the mechanisms responsible for enhanced thromboxane (TX) A2 biosynthesis in homozygous homocystinuria due to cystathionine-beta-synthase deficiency (CBSD), we measured a series of platelet and monocyte variables in 9 homozygous and 8 obligate heterozygous CBSD patients and evaluated their relationships to thromboxane formation, as reflected by urinary excretion of its major metabolite, 11-dehydro-TXB2 (TXM). Consistent with our previous data, homozygous CBSD patients showed abnormally high TXM excretion (1175 +/- 236 pg/mg creatinine vs. 284 +/- 39 in control subjects; p < 0.001). Significantly higher TXM excretion was also found in obligate heterozygotes (755 +/- 450 pg/mg creatinine; p < 0.05 vs. control subjects). All platelet and monocyte variables fell within the normal range in CBSD patients and none showed a correlation with TXM excretion (p always > 0.05). Our results argue against abnormalities of platelet and monocyte function being responsible for the abnormally high in vivo TXA2 biosynthesis in homocystinuria due to CBSD.

A role for platelets and thrombin in the juvenile stroke of two siblings with defective thrombin-adsorbing capacity of fibrin(ogen)

Binding of iodine-125-labeled thrombin to fibrin clots from two siblings with juvenile stroke was 30% of normal, and abnormally high amounts of the radioligand (not adsorbed by fibrin) were found in the supernatant. In concordance with this finding, supernatants from the patients' fibrin clots caused abnormal enhancement of platelet aggregation, ATP secretion, and binding of 125I-fibrinogen to platelets exposed to subthreshold concentrations of ADP or epinephrine. Hirudin suppressed the enhancing effect of the patients' supernatants, and substitution of gamma-thrombin for alpha-thrombin led to normalization of platelet responses. Under some experimental conditions, degradation of the patients' fibrinogen by plasmin was impaired. However, the euglobulin lysis time, the rate of fibrin degradation by plasmin, and the lysis of the patients' plasma clots by human melanoma tissue-type plasminogen activator were normal. Patients' plasmas, as well as purified fibrinogen, showed a prolonged thrombin time (partially corrected by 10 mM CaCl2) and an impaired release of fibrinopeptide A in response to thrombin. However, the release in response to reptilase was normal, and the reptilase, ancrod, and thrombin coagulase times were within control (normal) values. In addition, the patients' fibrinogen showed normal polymerization of preformed fibrin monomers, normal sialic acid content, and normal binding to ADP or epinephrine-stimulated platelets. Our studies support the concept that thrombin and platelets play an important role in the occurrence of stroke in these patients and suggest a direction to be followed to identify the mechanism(s) contributing to thrombosis in subjects with abnormal fibrinopeptide release.