Jaundice and antibodies directed against factors 8 and 9 in patients treated for haemophilia or Christmas disease in the United Kingdom

Mortality, life expectancy, and causes of death of persons with hemophilia in the Netherlands 2001-2018

BACKGROUND

Treatment of patients with hemophilia has advanced over the past decades, but it is unknown whether this has resulted in a normal life expectancy in the Netherlands.

OBJECTIVE

This observational cohort study aimed to assess all-cause and cause-specific mortality in patients with hemophilia in the Netherlands between 2001 and 2018 and to compare mortality and life expectancy with previous survival assessments from 1973 onward.

PATIENTS/METHODS

All 1066 patients with hemophilia who participated in a nationwide survey in 2001 were followed until July 2018.

RESULTS

Information on 1031 individuals (97%) was available, of whom 142 (14%) deceased during follow-up. Compared with the general Dutch male population, mortality of patients with hemophilia was still increased (standardized mortality ratio: 1.4, 95% confidence interval: 1.2-1.7). Intracranial bleeding and malignancies were the most common causes of death. Estimated median life expectancy of patients with hemophilia was 77 years, 6 years lower than the median life expectancy of the general Dutch male population (83 years). Over the past 45 years, death rates of patients with hemophilia have consistently decreased, approaching the survival experience of the general population. Over the past decades, mortality due to human immunodeficiency virus and hepatitis C virus infections has decreased, death due to intracranial hemorrhages has increased, and death due to ischemic heart disease has remained consistently low over time.

CONCLUSIONS

Survival in patients with hemophilia in the Netherlands has improved over time but is still lower than that of the general population.

Transfusion and hemovigilance in pediatrics

Hemovigilance is an essential part of the transfusion process and is defined as surveillance procedures covering the whole transfusion chain, from collection of blood and its components, intended to collect and assess information on unexpected or undesirable effects resulting from the therapeutic use of labile blood products and to prevent their occurrence or recurrence. The UK surveillance scheme has collected data for 16 years and is a model demonstrating how information on adverse incidents can be used to improve patient safety, influencing the management of donors and improved education and training for the many people involved in the transfusion process.

Rosemary Biggs MD FRCP (1912-2001) and Katharine Dormandy MD FRCP (1926-78): from laboratory to treatment and care of people with haemophilia

In 1977 the Haemophilia Society presented the first RG Macfarlane Award to Katharine Dormandy for her outstanding contribution towards the social and physical wellbeing of people with haemophilia and related disorders. In 1978 Rosemary Biggs was the second recipient of the Award given for similarly outstanding personal contributions. Dr Biggs worked under Dr RG Macfarlane at Oxford and in 1952 devised a laboratory test that identified two forms of haemophilia. Macfarlane realized the potential for replacement therapy which subsequently transformed the lives of haemophiliacs in the UK. Dr Biggs was director of the Oxford Haemophilia Centre (1967-77) and instrumental in documenting the increase in incidence of jaundice with the import of concentrates for infusion. Katharine Dormandy, Consultant Haematologist at the Royal Free Hospital in London, set up one of the country's foremost haemophilia centres, pioneered home treatment for haemophilic children and with Rosemary Biggs was involved in the social and educational welfare of affected families.

Chronic hepatitis in hemophilia

The relationship of chronic hepatitis B and/or liver dysfunction to treatment in 113 hemophiliacs was evaluated by the enzyme tests, SGOT and SGPT, and by the presence of circulating hepatis B surface antigen (HbsAg) or antibody (anti-Hbs). The hemophiliacs were divided into three groups according to treatment pattern. Individuals who had received multiple doses of plasma fractions, derived from four or more commercial lots were placed in tgroup I "large Exposure". Group II "Small Exposure" had been treated with fractions from three or fewer lots and Group III "Cryo" had never received commercial fractions, but had been treated with cryoprecipitate. Abnormal liver function tests (LFT's) were found in 87% of Group I and 76% of Group II, but in only 16% of the "Cryo" group. Differences in LFT's were not great between treated VIII and IX deficient patients. All patients treated with 100,000 units or more showed either persistent or intermittent abnormalities. In the high exposure group, this history of past, overt hepatitis had no influence on observed LFT's. The sera of all patients in the high exposure and all, except one, in the low exposure groups were positive for HbsAg or anti-Hbs by RIA. Splenomegaly was found in 13% of fraction-treated patients. We conclude that there is biochemical evidence of liver disease following large exposure to commercial VIII or IX fractions, which should temper the physician's decision to start treatment with these fractions. On the other hand, evidence that their continued use produces mounting liver dysfunction is insufficient to withdraw this very effective and life-changing treatment from these individuals.

Side effects of antihemophilic concentrates

Liver disease and thromboembolism are the most frequent and severe side effects associated with the use of clotting-factor concentrates in haemophiliacs. Knowledge and careful evaluation of the risk factors related to their development appear to be the most reasonable policy for prevention. themolysis due to significant isoantibody infusion and bleeding associated to abnormal platelet function occur more rarely during intensive replacement therapy with clotting factor concentrates. Finally, abnormalities of renal function have been observed in a number of patients, though they seem to be of minor clinical importance. These complications do not justify withdrawal or limitation of the very effective and life-changing use of concentrates. However, awareness of their occurrence and of their danger requires that specialized hemophilia centres carry out, at frequent intervals, clinical and laboratory testing of the target organs to allow an early detection.

Jaundice and hepatitis B surface antigen and antibody in Greek haemophiliacs

The incidence of hepatitis B surface antigen (HBsAg) and antibody (HBsAb) in 101 Greek multitransfused haemophiliacs with or without a previous history of jaundice was studied. Using the haemagglutination inhibition assay, HbsAg was detected in 9.9%, HBsAb in 61.3% and HBsAg plus Ab in 11.8% of the cases. The incidence of jaundice was 14.8%. Liver function was tested by means of Normotest, SGOT, SGPT and serum protein electrophoresis. Abnormal values of liver function tests were found in 47% of the patients. The abnormal findings were related to the presence of HBsAg or Ab and to the history of jaundice. There was no significant difference between the various groups of patients.

Case studies: orthopaedic surgery in adult patients with haemophilia A with inhibitors

Whilst orthopaedic surgery in haemophilia patients without inhibitors is now relatively common in specialized centres, until recently there have been only a few sporadic instances of surgery having been undertaken on patients with inhibitors. The availability of recombinant activated factor VII (rFVIIa) for haemostatic cover during surgery allows procedures to be performed that previously may not have been considered possible. Complications associated with thrombosis are rare in haemophilia patients with inhibitors, but bleeding complications remain a concern. Globally, experience of performing orthopaedic surgery in these patients is increasing and many successful outcomes have been reported. However, more knowledge relating to the incidence and type of bleeding complications liable to be encountered, together with further information about appropriate rescue treatment, would be valuable. Data relating to long-term follow-up after surgery would be useful, as would a comparison of outcomes between haemophilia patients with and without inhibitors. Optimal dosing regimens for rFVIIa as surgical cover are still to be determined and further information is required relating to the cost effectiveness of rFVIIa in surgery. Further study should address these issues.

A postmarketing surveillance study of the safety and efficacy of ReFactoR (St Louis-derived active substance) in patients with haemophilia A

This clinical trial evaluated the safety and efficacy of ReFacto (St Louis-derived active substance) in patients with severe or moderately severe haemophilia A over a period of 6 months or 50 exposure days (EDs), whichever occurred first. Sixty patients, 58 previously treated and two previously untreated, were enrolled into this study. This was an open-label, multicentre, postmarketing surveillance study in which patients received prophylaxis or on-demand treatment as determined by their doctor. Surgical prophylaxis was evaluated in seven patients requiring elective surgery. Thirty-two patients aged <1 to 66 years (median 19.5) received prophylaxis and 28 patients, aged 1-71 years (median 33.5), received on-demand treatment. The majority of patients had severe haemophilia A (FVIII:C < 2%): 84.4% in the prophylaxis group and 85.7% in the on-demand group. Prophylaxis with ReFacto was associated with a median of 6.7 bleeds per year (range: 0-37). The investigator's assessment of final outcome for prophylactic treatment was excellent or effective for 93.1% of patients. ReFacto resolved 92.8% of bleeds with one or two infusions. The investigator's assessment was excellent or good for 98.2% of bleeds treated with ReFacto. Haemostasis was achieved for all seven surgical cases and ReFacto gave an excellent or good response for each. The nature and incidence of adverse events was as expected and no new safety concerns emerged. One previously treated patient (PTP) developed a high-titre inhibitor (maximum 75 BU) and one minimally treated patient (MTP) developed a low-titre inhibitor while on the study but eventually achieved high titres (maximum 30 BU) after immune tolerance therapy was initiated with a plasma-derived FVIII product. One previously untreated patient (PUP) developed a transient low-titre inhibitor (0.4 BU). Other serious adverse events (SAEs) were unrelated to study treatment. There were no allergic events. The results of this study are consistent with the previously published ReFacto pivotal studies.

Human recombinant DNA-derived antihemophilic factor in the treatment of previously untreated patients with hemophilia A: final report on a hallmark clinical investigation

BACKGROUND

Development of recombinant factor VIII (rFVIII) replacement therapy represents a milestone in the treatment of hemophilia A.

OBJECTIVE

The objective of this long-term, multicenter study was to assess the safety, efficacy and rate of inhibitor formation of rFVIII (Kogenate) in the treatment of hemophilia A in a group of previously untreated patients (PUPs).

PATIENTS AND METHODS

Between January 1989 and October 1997, 102 evaluable patients (mean age 3.9 years) were treated with rFVIII as sole therapy for prophylaxis against bleeding or for hemorrhage. Patients with mild hemophilia were treated for > or =2 years, while those with moderate or severe hemophilia were treated for > or =5 years or 100 exposure days.

RESULTS

All patients responded well to therapy, so that 82% of bleeding episodes required a single infusion for treatment. Only four mild drug-related adverse events were recorded during the study for an overall rate of 0.03% (4/13 464 infusions). No viral seroconversions were observed. The inhibitor incidence in PUPs with severe hemophilia was 29% (19/65). Overall, inhibitory antibodies developed in 21 patients (20.6%). Inhibitor titers were low (<10 Bethesda Units) in nine of the 21 patients despite continued episodic treatment with rFVIII and transient in eight patients receiving episodic treatment (seven low titer, one high titer). Eight high-titer inhibitor patients were treated with immune-tolerance induction therapy; five had successful outcomes.

CONCLUSIONS

The observed incidence of inhibitor formation is similar to studies of PUPs receiving plasma-derived FVIII. These results demonstrate the safety and efficacy of rFVIII in long-term treatment of hemophilia A.

The epidemiology of inhibitors in haemophilia A: a systematic review

This paper emphasizes the importance of distinguishing between the prevalence, incidence and cumulative incidence of inhibitors in haemophilia A. Incidence and cumulative incidence data will include patients with transient inhibitors or whose inhibitors have been eliminated by treatment. As these will not be included in prevalence data, prevalence studies will tend to give rise to lower figures than incidence studies. As a result, the most accurate estimates of the true risk of inhibitor development comes from prospective studies of newly diagnosed haemophiliacs who are tested regularly for the presence of inhibitors. This paper reports a systematic review of the best available evidence relating to the epidemiology of inhibitors in haemophilia A. Cohort studies, registry data reporting incidence or prevalence of inhibitors in patients with haemophilia A, and prospective studies of factor VIII (FVIII) in the treatment of previously untreated patients which reported the development of inhibitors as an outcome, were included in the review. The overall prevalence of inhibitors in unselected haemophiliac populations was found to be 5-7%. The cumulative risk of inhibitor development varied (0-39%). Incidence and prevalence were substantially higher in patients with severe haemophilia. Studies of patients using a single plasma-derived FVIII (pdFVIII) preparation reported lower inhibitor incidence than those using multiple pdFVIII preparations or single recombinant FVIII preparations. Incidence data should be used to estimate the likely demand for treatments aimed at eliminating inhibitors, whereas the best estimates of the overall burden to the National Health Service (NHS) of treating bleeding episodes in patients with continuing inhibitors will come from prevalence studies.

The effect of CpG sequences on the B cell response to a viral glycoprotein encoded by a plasmid vector

The effect of palindromic CpG sequences on the B cell response to plasmid vectors expressing a highly immunogenic viral glycoprotein was investigated. Methylation of the CpG sequences of bacterial expression vectors abolished their ability to induce an antibody response to the transgene product in mice. The antibody response could be rescued by concomitant injection of oligonucleotides carrying immunostimulatory sequences. The B cell response to two plasmid vectors, both expressing the same viral glycoprotein but containing a different content of the highly stimulatory AACGTT motif, was compared. Comparable B cell responses were induced to the two constructs given at an optimal vaccine dose while the vector containing additional palindromic sequences resulted in higher antibody titers at a suboptimal dose. These data indicate that deletion of CpG motifs or methylation of such sequences in plasmid DNA can abrogate the immune response to the vector encoded antigen and might thus enhance their usefulness as gene therapy vehicles.

Incidence of inhibitors in haemophilia A patients--a review of recent studies of recombinant and plasma-derived factor VIII concentrates

The development of inhibitors to factor VIII or IX is the most serious complication of haemophilia therapy. While early surveys revealed inhibitor prevalences of 3.6-25%, recent studies, especially those using recombinant DNA-derived products, have prompted speculation as to whether ultrapurified products may cause a higher incidence of inhibitors. Although studies of ultrapure rFVIII in previously treated patients have not shown an increased inhibitor risk, in previously untreated patients (PUPs) with severe haemophilia A (factor VIII < 2%), cumulative incidences of approximately 30% have been reported. The majority of these inhibitors are low responders; many have disappeared spontaneously despite continued treatment with the study product (i.e. transient inhibitors), and were most probably detected as a consequence of frequent inhibitor testing. The mutation causing haemophilia has recently been shown to be a significant risk factor for developing an inhibitor; mutations leading to the absence of endogenous factor VIII protein (for example, large multidomain deletions, nonsense mutations, isochromosomal intron 22 inversions) are associated with the highest risk of inhibitor development. Furthermore, recent prospective studies of plasma-derived products reveal inhibitor incidences (i.e. 21-52%) that are comparable to those obtained with recombinant products. When comparing the incidences of high-responder inhibitors (> 10 BU) among recent prospectively studied severe haemophilia A cohorts (i.e. 11-41%), differences between plasma-derived and recombinant products cannot be discerned. New studies of either recombinant or plasma-derived products should consider all known parameters influencing inhibitor formation, thereby facilitating meaningful comparisons of inhibitor risk.

The molecular basis of haemophilia B

Over the past 15 years, our knowledge of the molecular basis of haemophilia B has increased dramatically. Following the cloning and characterization of the factor IX gene in 1982, major advances have been made in documenting the molecular pathology that underlies this condition. This review will summarize the current state of information in this area, and the reader is referred to the Haemophilia B Mutation Database World Wide Web site at http://www.umds.ac.uk/molgen/haemBdatabase for a complete current listing of the mutations that cause this phenotype. In addition, other recent reviews have discussed complementary issues relating to this topic.

Incidence of development of factor VIII and factor IX inhibitors in haemophiliacs

The development of factor VIII:C inhibitors remains one of the most serious complications of repeated transfusion in patients with haemophilia A. The proportion of patients affected has been reported to range from 3.6% to 25%, but these figures have been derived mainly from retrospective data and from total numbers of known haemophiliacs instead of number at true risk. The assessment here is based on a prospective study, started in 1976, on the incidence of inhibitor development in haemophiliacs born after 1970 whose FVIII or FIX activity was 5% or less, and who had received replacement therapy at least once. 46 of 63 children with haemophilia A and 13 of 17 with haemophilia B fulfilled the enrollment criteria. Inhibitors developed only in haemophilia A patients who had previously been treated with FVIII products--inhibitor concentrations were high in 12 and low in 3. Inhibitors developed in 24% (15/63) of all haemophilia A patients, and in 52% (14/27) of those with severe disease. The incidence of inhibitor development for all haemophilia patients was 39.1 per 1000 patient-years of observation. All inhibitors were first detected when patients were aged 0.08-5.2 years. The cumulative risk was 33% at age 6 years. The findings indicate that previous reports have underestimated the risk of acquiring FVIII inhibitors. Prospective, standardised studies, especially in children, are needed for the assessment of the true risk of this complication.

The Impact of Clotting Factor Concentrates on the Immune System in Individuals With Hemophilia

All reported studies to date, whether comparative or not, have shown a tendency toward a slower decrease in CD4+ numbers in patients receiving very high-purity agents with the rapidity in fall-off being affected by level of CD4+ numbers (low CD4+ numbers decreasing more rapidly), age (older persons showing more rapid CD4+ cell fall-off), and anti-HIV therapy. Clearly, these observations need to be extended in numbers, and the high-purity agents should also be similarly compared with the very high-purity therapies.

Haemophiliacs with factor VIII inhibitors in Finland: prevalence, incidence and outcome

Twenty-five of the 139 Finnish patients (18.0%) with severe haemophilia A alive in 1960 or born later have or have had an inhibitor against factor VIII. 19 of the 110 patients alive have an inhibitor and the current prevalence is 17.3%. The incidence of new inhibitors was 10.3 per thousand patient years for the observation period starting from 1960, median 16 years. The age dependent cumulative risk of developing an inhibitor was 22% at the age of 10. There have been no deaths from bleeding since 1976, which has resulted in a marked decrease in mortality. The annual death rate of patients with inhibitors was 5.8 per thousand years of life in 1980-89 compared to 41.7 in the previous decade. The recent progress in the modalities for treatment of bleedings has markedly improved the outcome of patients with factor VIII inhibitors.

Acquired factor XI inhibitors in congenitally deficient patients

Four factor XI (F XI)-deficient patients are described, all of whom formed circulating anticoagulants against F X1. In the three most severely affected patients (F XI 0%-6% activity), the anticoagulant appeared to have been stimulated by plasma infusion. However, in the milder case (25% F XI activity), no infusion had been documented. The findings in these cases emphasize the diversity of F XI inhibitors in congenitally deficient patients. Awareness of the potential development of these inhibitors will be helpful in both daily management and perioperative care of such patients.

High risk of non-A non-B hepatitis after a first exposure to volunteer or commercial clotting factor concentrates: effects of prophylactic immune serum globulin

After a first exposure to factor VIII concentrates, 9/9 British patients treated with U.S.A.-derived commercial products, and 10/12 treated with British volunteer (NHS) products, developed acute non-A, non-B (NANB) hepatitis. Hepatitis following commercial products was more severe, and of shorter incubation. High previous exposure to NHS blood products seemed to prevent NHS but not commercial factor VIII-induced hepatitis; the latter was also not attenuated by administration of U.S.A.-derived commercial immune serum globulin (ISG). After a first exposure to NHS factor IX concentrates without ISG, 4/4 patients developed short incubation NANB hepatitis; one also contracted prolonged incubation hepatitis B. One patient treated with ISG and factor IX of proven infectivity did not develop hepatitis, suggesting protection by ISG. Observed differences between concentrates might be attributable to their content of different NANB agents, but dose-related effects could provide alternative explanations. This data provides a basis for comparative assessment of new products of possible reduced infectivity in only small numbers of patients.

Progressive liver disease in haemophilia: an understated problem?

In an 8-year study of 79 unselected patients with haemophilia who had received clotting factor concentrates, there was evidence of chronic progressive liver disease in at least 17 (21%). 8 patients had chronic active hepatitis and 9 had cirrhosis (5 with oesophageal varices). Histological evidence suggested that non-A non-B hepatitis was mainly responsible, although the influence of other viruses could not be excluded. Serial liver biopsies showed progression from chronic persistent hepatitis to chronic active hepatitis and cirrhosis within 6 years, suggesting that chronic persistent hepatitis in haemophiliacs is not as benign as hitherto supposed. Symptoms and abnormal physical signs were uncommon in these patients. There was no relation between degree of abnormality of serum aminotransferase levels and severity of the underlying liver disease. It is anticipated that liver disease in haemophiliacs will become an increasing clinical problem in the future.

HLA antigens in hemophiliacs A with or without factor VIII antibodies in a Venezuelan Mestizo population

Twenty-eight unrelated hemophilia A patients, seven of them with anti-factor VIII antibodies were typed for HLA-A, B, C antigens and 25 of them for HLA-DR. The results show a significant difference in HLA-DR4 frequency between hemophiliacs with antibodies who lack this antigen and hemophiliacs without antibodies, in whom HLA-DR4 is increased as compared to a healthy control series. This data suggests that DR4 may be associated with a factor preventing anti-factor VIII immunization.

Evidence that less replacement therapy is required for dental extractions in hemophiliacs

The requirements for factor VIII (AHF) or factor IX (PTC) of hemophilic patients undergoing dental extractions were evaluated to determine the minimum effective regimen. Sixteen patients underwent 19 operative procedures. The mean total dose of factor VIII or IX was 45.8 U/kg for 11 procedures with preoperative replacement therapy and 34.5 U/kg for the 8 without. Four patients received no replacement therapy at all. Our results compared favorably to published studies employing factor replacement alone or in combination with antifibrinolytic agents such as epsilon-amino-caproic acid (EACA), with respect to blood products utilized and duration of hospitalization. However, our patients received less factor replacement than usually suggested. General anesthesia with intubation, a common recommendation, was not required in any patients. Dental extractions can be carried out in hemophiliacs using less replacement therapy than currently recommended. In some circumstances, no replacement therapy may be necessary. The reported efficacy of antifibrinolytic agents in reducing the requirement for replacement therapy is difficult to assess because of the relatively large amount of prophylactic factor replacement used in conjunction with these agents.

Induction of tolerance to factor VIII in a child with a high-titer inhibitor: in vitro and in vivo observations

High dose factor VIII concentrate was infused over 12 months in a 3-year-old child with hemophilia A and a high-titer inhibitor. This regimen was successful in producing clinical tolerance to the factor VIII and was associated with a fall of inhibitor titer from 85 BU to less than 1 BU. Subsequently, a rise in inhibitor to peak at 3.5 BU correlated with a decrease in infusion dose. In vitro studies using a microdroplet assay for immunoglobulin synthesis in the presence of varying concentrations of factor VIII was carried out prior to the clinical trial. This system indicated that the patient's peripheral blood mononuclear cells were stimulated to release IgG by 0.01 U/ml factor VIII coagulant activity and inhibited at 0.9 U/ml FVIIIc. Lymphocyte subsets were monitored during the course of therapy. The ratio of Leu-3a+/Leu-2a+ (helper/suppressor) varied considerably, fluctuating between a peak of 4.4 and low point of 0.6, with the initial pretrial ratio being 1.2.

Non-A non-B hepatitis after transfusion of factor VIII in infrequently treated patients

Thirty patients who had not previously received treatment with factor VIII concentrate or who had been treated only infrequently with factor VIII concentrate were studied after a transfusion of factor VIII. Tests of liver function were performed frequently. Four patients had evidence of chronic liver disease before transfusion. In 17 of the remaining 26 patients serum transaminase activities became raised and 10 patients developed jaundice. All of the nine patients who had not previously received factor VIII transfusion developed non-A non-B hepatitis. Four out of 10 patients followed up for a year had persisting abnormalities of liver function. The pattern of illness suggests that more than one serotype of non-A non-B hepatitis virus may be transmitted by factor VIII concentrate prepared by the National Health Service from volunteer donors in the United Kingdom.

Circulating immune complexes in haemophilia and von Willebrand's disease

Sera from 63 patients with haemophilia A, 21 with haemophilia B and 29 with von Willebrand's disease were screened for the presence of circulating immune complexes (CICs), serological markers of hepatitis A and B virus, autoantibodies and factor VIII or factor IX inhibitors. CICs were detected by the 125J Clq binding assay (ClqBA), the solid phase conglutinin assay (KgBSP) and the solid phase Clq assay (ClqSP). The incidence of CICs detected by the ClqBA and the ClqSP methods in haemophiliacs and in von Willebrand patients was higher than that observed in normal subjects, while the prevalence of CICs detected by the KgBSP method was not. The presence of CICs was not correlated with patient age, severity of disease, presence of hepatitis B virus serological markers, abnormal liver function tests or factor VIII inhibitors. A significant connection was demonstrated between CICs detected by the ClqBA method and replacement therapy when the dose administered over 1 year was over 20 000 U of factor VIII or IX concentrates. The high proportion of CICs in von Willebrand's disease, not connected with the replacement therapy or the presence of serological markers of hepatitis virus, is in agreement with the possibility that immune complexes may be related to the disease itself and independent, at least in part, of exogenous agents.

Treatment of haemophilia and related disorders in Britain and Northern Ireland during 1976-80: report on behalf of the directors of haemophilia centres in the United Kingdom

A five year survey of the treatment of patients in the United Kingdom suffering from haemophilia and related disorders was carried out on behalf of the directors of haemophilia centres. The survey showed an increase in the number of patients receiving treatment from the centres, a substantial increase in the total amount of therapeutic materials used, and an increase in the average amount of factor VIII or factor IX used yearly per patient. Home treatment became established for severely affected patients and accounted for roughly half of the total amount of material used. Study of the acquisition of factor VIII or factor IX antibodies (inhibitors) in patients with haemophilia A or haemophilia B showed no increase in antibodies during the survey period, despite the increased use of factor VIII and factor IX concentrates. The occurrence of acute hepatitis in treated patients was also studied and no increased incidence was observed. A near normal median expectation of life in patients with severe haemophilia A was found.

Role of plasma-exchange in the management of patients with factor VIII inhibitors

Plasma-exchange is one of many treatments available for the prevention and management of hemorrhage in patients with factor VIII inhibitors. Details of exchange technique and the frequency of treatment are determined by the clinical situation, venous access and the availability of equipment, staff and blood products. In view of the many difficulties associated with plasma-exchange, other treatment options are likely to be preferred in most circumstances. The technique remains attractive as a means for reducing inhibitory activity before elective surgery and during life-threatening hemorrhage.

Factor VIII inhibitors: a clinical overview

There is much evidence to indicate that inhibitors to Factor VIII in patients with classical hemophilia are the result of an immunological response to exposure to material (VIII:C or VIII:CAg) that is absent or present in reduced amounts in these patients. The inhibitor is an antibody that is usually restricted in immunochemical composition and in many instances contains predominantly or exclusively gamma G3 or gamma G4 heavy chains. Exposure to Factor VIII in many inhibitor patients leads to typical anamnestic responses with marked increases in the level of the inhibitor. The tendency to develop inhibitors and the clinical characteristics of the inhibitor may be affected by genetic factors, basal levels of Factor VIII:C and/or VIII:CAg, and the nature and amount of the "immunizing" material. Currently accepted therapeutic modalities are aimed primarily at the management of acute bleeding episodes.

Characterization of an antibody to factor VIII in a patient with acquired hemophilia with circulating immune complexes

A 73-year-old previously healthy woman was admitted because of severe bleeding from esophagitic lesions and intraabdominal bleeding following hysterectomy. Acquired hemophilia, probably due to an IgG antibody to factor VIII (64 inhibitor units/ml) was noticed, the VIII:C in the patient's plasma being 18% or normal. Immune complexes isolated by polyethylene glycol precipitation had only a weak factor VIII inhibiting activity whereas IgG purified from the complexes and monomeric IgG present in her plasma exerted a strong inhibition. Removal of the complexes from plasma had no effect on the inhibitor titer thus indicating that only a minor part of the antibody was circulating as immune complexes. Plasma or purified IgG from the patient decreased the VIII:C of normal plasma to 18 og 14%, respectively, total inhibition being impossible to achieve even in antibody excess, probably reflecting residual activity of factor VIII bound to the patient's antibodies. The ristocetin cofactor activity of normal plasma was unaffected by the antibodies. Transfusion of factor VIII concentrate to the patient resulted in therapeutic levels of circulating factor VIII and transfused factor VIII circulated longer than usual. Partial remission of the disease with adequate levels of VIII:C occurred after 3 months.

Prothrombin complex concentrates for clinical use

Prothrombin complex concentrates prepared for clinical use are reviewed with emphasis on frequently observed adverse reactions such as viral hepatitis and thromboembolic complications. Preparation procedures and quality control are described briefly, and the use of these concentrates in the treatment of hemophilia A patients who develop factor VIII inhibitors is also described. The causes of and methods for the detection of potential thrombogenicity are discussed and suggestions which may result in a safer product are made.

The role of intensive plasma exchange in the prevention and management of haemorrhage in patients with inhibitors to factor VIII

A strategy for the prevention and management of haemorrhage in patients with inhibitors to factor VIII by intensive plasma exchange and human factor VIII infusion is described. The advantages and disadvantages of this approach are discussed in the light of the authors' experience with the technique and the alternative methods of treatment described in the literature.

Hepatitis B surface antigen circulating immune complexes (HBsAg-CICs) in patients with bleeding disorders

Approximately 90% of 67 multi-transfused patients with bleeding disorders were positive either for anti-HBs (85%) or HBsAg (45%). Using a polyethylene glycol trypsinization assay, we found anti-HbsAg-containing specific circulating immune complexes (HBsAg-CICs) in 3 of the 57 HBsAg-negative haemophiliacs possessing anti-HBs. The occurrence of HBsAg-CICs may be a regular event in the conversion phase of HBs infection. Circulating immune complexes as detected by the anticomplementary assay were found in 32 of the 67 (48%) patients.

Liver dysfunction in Pennsylvania's multitransfused hemophiliacs

Transaminase values [alanine amino transferase (ALT) and aspartate amino transferase (AST)] and markers for hepatitis B were serially determined in 558 hemophiliacs exposed to blood products. Hepatitis B surface antigen (HBsAg) persistent for over 12 months was present in 6% of the patients. Antibody to hepatitis B surface antigen (anti-HBs) was noted in 90% of the 259 patients treated with factor VIII or IX concentrates but in only 49% of the 43 patients treated with fresh frozen plasma (FFP) or cryoprecipitate. Persistently abnormal transaminase values were noted in 31% of the patients treated with commercial concentrates but in only one (2%) of the patients exposed to cryoprecipitate or FFP. This difference continued even when the two groups of patients were matched for the amount of blood products, up to 50,000 units, which they had received in the study period. In the concentrate-treated patients, no correlation could be found between transaminase values and the number of units of factor VIII or IX they had received during the six years of the study (1973-1978).

Percutaneous liver biopsy and chronic liver disease in haemophiliacs

Systematic screening of forty-seven haemophiliacs in Sheffield revealed abnormal liver-function tests in thirty-six (77%), with a tendency for these abnormalities to persist. To assess the importance of these abnormalities, percutaneous liver biopsy was carried out on eight symptom-free patients under factor-VIII cover. A wide spectrum of chronic liver disease was demonstrated, including chronic aggressive hepatitis and cirrhosis. The liver pathology bore no relation to clinical history or to biochemical findings. Hepatitis-B-virus markers were common, but evidence suggests that this is not the only factor contributing to the development of liver disease. The high incidence of chronic liver disease seems to be a recent development and is probably related to factor-concentrate replacement therapy.

Spontaneously acquired factor IX inhibitor in a nonhemophiliac child

A 2 1/2-year-old, previously healthy child developed progressive swelling of the left leg and a hematoma of the anterior chest wall associated with a falling hemoglobin concentration, as a result of a spontaneously acquired Factor IX inhibitor. Successful management of her condition required a four-volume exchange transfusion and immunosuppressive therapy consisting of cyclophosphamide for four days and prednisone for one month. A brief review of the literature regarding the occurrence and nature of acquired coagulation factor inhibitors and the role of immunosuppressive therapy is also presented.