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.

A variety of disease- and treatment-related factors affect the coagulation system and the risk of bleeding and thrombotic complications in patients with multiple myeloma (MM) and related plasma cell disorders (PCD). As commonly observed in other cancer settings, the malignant clone induces a cytokine environment responsible for a hypercoagulable state. The increase of blood viscosity and impairment of platelet and coagulation function due to circulating monoclonal proteins are considered key mechanisms in the hemostatic abnormalities frequently detected in patients with PCD. However, clinically significant bleeding is relatively rare and poorly correlated with these abnormalities. Management is often challenging because of the multifactorial pathogenesis and underestimation or misdiagnosis of acquired bleeding disorders, particularly acquired von Willebrand syndrome. In recent years, growing interest in thromboembolic risk has emerged after the introduction of novel and more effective antimyeloma agents (thalidomide and lenalidomide), which was associated with increased risk of venous thromboembolism, particularly when associated with dexamethasone and multiagent chemotherapy in newly diagnosed patients. The clinical impact of bleeding and thrombotic complications in patients with PCD, with emphasis on MM, will be discussed in this review, reporting the current knowledge about pathophysiologic mechanisms and implications for management.

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.

Recurrent joint bleeding leading to progressive musculoskeletal damage (hemophilic arthropathy), in spite of on-demand replacement with deficient factor concentrates, is the clinical hallmark of severe hemophilia A and B (i.e., the congenital deficiencies of coagulation factors VIII and IX with circulating levels <1 IU/dL). Fifty years of clinical experience, which began in Northern Europe and then initiated in other European countries and in North America, up to the recent randomized clinical trials, have provided definitive evidence that preventing bleeding from an early age through long-term regular prophylactic concentrate infusions limits the adverse clinical consequences of arthropathy and its complications in the quality of life of hemophilic children. Primary prophylaxis started after the first joint bleed and/or before the age of 2 is now the evidence-based, first-choice treatment in severe hemophilia. Interestingly, recent data also suggest a role for early prophylaxis in preventing inhibitor development, the most serious complication of hemophilia therapy. Secondary prophylaxis is aimed to avoid (or delay) the progression of arthropathy. The earlier the treatment is started, the better the outcomes in joint status and quality of life. Although prophylaxis has radically transformed the natural history of severe hemophilia, relevant barriers to its implementation and diffusion remain. Beyond the obvious economic constraints and problems with venous access and long-term adherence, uncertainties regarding the optimal prophylaxis regimen require further evaluation in prospective studies to optimize approaches based on definite outcome measures and cost-effectiveness/cost-utility analyses. Scientific evidence, current clinical strategies, and open issues of prophylaxis in children with hemophilia will be addressed in this review.

The pathogenesis and treatment of retinal vein occlusions (RVO) are largely unclear. Prevalence of cardiovascular risk factors and of thrombophilic abnormalities was evaluated in 117 patients (61 M, 56 F; mean age 51 +/- 13 years) with a history of RVO (62 central, CRVO; 48 branch, BRVO; 7 both) and in 202 age- and sex-matched control subjects. Cardiovascular outcome after a mean 8.2 year follow-up was recorded for 90 patients. Arterial hypertension was significantly more frequent in patients than in controls (64.9 vs. 28.2%; adjusted OR 4.5 95% CI 2.4-7.9; P < 0.0001), as well diabetes mellitus (17.9 vs. 7.9%; P < 0.05). Antithrombin, Protein C, Protein S and homocysteine levels, lupus anticoagulant, anticardiolipin antibodies, FV G1691A and prothrombin G20210A polymorphisms were comparable in the two groups, nor were different according to RVO localization or to the age at event. BRVO patients were significantly older (55 +/- 9 vs. 47 +/- 15 years; P = 0.002) and had higher prevalence of diabetes, overweight and hypertension (29.2 vs. 8.1%; 83.3 vs. 58.1%, 79.2 vs. 56.5%; P always <0.05). In 58/90 (64%) patients for whom clinical follow-up was available, new vascular events were recorded (coronary/cerebral, n = 38); only 22 patients (24%) received long-term antiplatelet agents (mostly aspirin 100 mg/d), with lower, but not statistically significant, prevalence of overall vascular recurrence (45.4 vs. 70.6%, P = 0.06). High rate of vascular recurrence is shown in patients with previous RVO, in which conventional cardiovascular risk factors play a major role, especially in BRVO and in older patients.