With the introduction of safe and effective factor VIII/IX-bypassing agents--recombinant activated factor VII (rFVIIa) and plasma-derived activated prothrombin complex concentrates (pd-APCC)--elective orthopaedic surgery (EOS) is a viable option for haemophilia patients with inhibitors. We report a series of patients with haemophilia and inhibitors undergoing EOS between 1997 and 2008 using bypassing agents to provide haemostatic cover. All inhibitor patients undergoing EOS and receiving rFVIIa, plasma-derived prothrombin complex concentrates (pd-PCC) or pd-APCC as haemostatic cover were included. Patients were operated on by the same surgeon and were managed by the same haemophilia treatment centre. Forty procedures (25 minor and 15 major) were conducted in 18 patients. Twenty-one minor cases were covered using rFVIIa, three with pd-PCC, and one with pd-APCC; all major cases were covered using rFVIIa. Bleeding was no greater than expected compared with a non-haemophilic population in all 25 minor procedures. In the major procedure group, there was no excessive bleeding in 40% of cases (6/15) and bleeding completely stopped in response to rFVIIa. For the remaining nine cases, bleeding response to rFVIIa was described as 'markedly decreased' or 'decreased' in 4/15 cases and 'unchanged' in 5/15 cases. Overall, efficacy of rFVIIa, based on final patient outcome, was 85%. One death occurred as a result of sepsis secondary to necrotizing fasciitis. Good control of haemostasis can be achieved with bypassing agents in haemophilia patients with inhibitors undergoing minor EOS; rFVIIa was used as an effective bypassing agent, enabling EOS in patients undergoing minor and major procedures.

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SummaryIn a study of 170 haemophilia A patients, 43 were found to have an inhibitory effect; seven had anti-factor VIII inhibitors (a-fVIII) (A), 18 had lupus anticoagulants (LAs) with a strong (B: 12) or weak (C: 6) time-dependent effect and 18 had no time-dependent LAs (D). The a-fVIII showed a neutralizing effect only against factor VIII and negative diluted Russell viper venom time (dRVVT). The LAs were diagnosed by dRVVT; the Staclot® LA agreed with the dRVVT. During the study, three patients changed from an a-fVIII to an LA pattern; they also modified their clinical response.Our prevalence of a-fVIII was low (4%) and we found 21% of LA, with a high (50%) prevalence of time-dependent inhibition. This pattern raises the possibility of the coexistence of LA and a-fVIII, stressing the need to develop specific tests to identify a-fVIII and LA.

Development of inhibitors against factor VIII (FVIII) or FIX is the most serious complication of replacement therapy in patients with haemophilia. Haemophilic pseudotumours in a patient with inhibitors can lead to devastating consequences. The aim of this study is to show our experience in the treatment of 10 pseudotumours in 7 patients with inhibitors who were treated by the same multidisciplinary team in the period between January 2000 and March 2013. Seven severe haemophilia A patients were treated at the Haemophilia Foundation in Buenos Aires, Argentina, for 10 pseudotumours. Eight were bone pseudotumours and two soft tissue. All patients underwent imaging studies at baseline to assess the size and content of the lesion. The patients received Buenos Aires protocol as conservative treatment of their pseudotumours for 6 weeks, after which they were evaluated. Only one patient responded to conservative treatment. Surgery was performed on the others six patients, since their pseudotumours did not shrink to less than half their original size. Any bleeding in the musculoskeletal system must be treated promptly in order to prevent pseudotumours. When pseudotumours do appear in inhibitor patients, they can be surgically removed when patients received proper haemostatic coverage, improving the quality of life of these patients.

Summary. Background: The recessive X-linked disorder hemophilia A (HA) is rarely expressed in female carriers, most of whom express about half of normal factor VIII activity (FVIII:C). Objective: To propose an integrative assessment model for the binary role of the phase between the mutated F8 and the active X-chromosome (Xa) in FVIII:C in HA carriers. Methods: We studied 67 females at risk of severe HA, comprising five symptomatic females (FVIII:C < 1.5 IU dL À1 ) and 14 controls. A correlation study between FVIII:C (observed vs. expected) and X-chromosome inactivation (XCI) patterns (XIPs; androgen receptor gene [AR] system) in blood leukocyte DNA was performed in carriers, by comparison of a model correlating FVIII:C and XIP with arbitrary models devoid of biological significance, and with FVIII:C levels in non-carriers (mean model) as a proxy from background data dispersion not influenced by XIP. Results:We provide proof-of-concept example from a family presenting with extremely skewed XIPs in which the severe HA phenotype appeared in a heterozygous carrier of a crossover between AR and F8 loci that phased the mutated F8 with the maternally inherited Xa. Furthermore, four cases of severe HA affected women who had a combination of a heterozygous F8 mutation and extremely skewed XIPs in leukocytes or oral mucosa are presented. Correlation analyses between FVIII:C levels and XIPs in carriers (n = 38) but not in non-carriers (n = 20) showed highly significant differences between the proposed correlation model and models without biological significance. The data support a binary influence of XCI, either increasing or decreasing the FVIII:C, subject to the underlying phase set between the F8 mutation and XCI. Conclusions: Our evidence suggests that the phase between XCI and mutated F8 acts as a molecular switch conditioning FVIII:C levels and HA expression in carriers.

Episodic CFC replacement over a large range of doses does not alter the natural course of bleeding in haemophilia or the musculoskeletal deterioration and should not be recommended as a long term option for treatment. Prophylaxis is the only way to preserve musculoskeletal function in haemophilia.

In this study, we describe a flow cytometry (FC) system for detecting antibodies to factor VIII (FVIII) and compare its results with those of enzyme-linked immunosorbent assay (ELISA) that detects both inhibitory (I-Ab) and non-inhibitory (NI-Ab) antibodies and the Nijmegen modification of the Bethesda method, detecting I-Ab. FC was set up in our laboratory. Recombinant FVIII (rFVIII) was coupled to microspheres (FVIII-m) and reacted with different plasma dilutions. Microspheres without rFVIII were used as control (control-m). Captured anti-FVIII antibodies were detected using anti-human IgG. Plasma samples from the following patients with severe haemophilia A (SHA) patients were evaluated: 17 P (patients without I-Ab, <0.5 BU mL(-1)); 13 PI (patients with I-Ab, 1.1-8200 BU mL(-1)). Of these 13, two PI were referred during immune tolerance induction (ITI), and plasmas from 12 healthy donors (HD) were evaluated. Semiquantitative results were given as an index (the highest mean fluorescence intensity ratio between FVIII-m and control-m multiplied by the inverse of the corresponding plasma dilution). Both plasma and serum were suitable for the test. FC agreed with the Bethesda method (r = 0.8; P = 0.0001). FC and ELISA had 80% of coincidence. Four of 17 patients (23.5%) had NI-Ab by FC, and two of them developed high levels of I-Ab later on. This test provides a useful alternative for measuring FVIII antibodies supplementing Bethesda assay. FC is fast and easy to perform. No more than 200 μL of plasma or serum is required especially making it useful for paediatric patients.

Selective angiographic embolization of knee and elbow arteries is a feasible procedure that can prevent repetitive bleedings, which would translate in better joint outcomes for these patients.