Comparison of anti-human and anti-porcine factor VIII inhibitor levels in 63 patients with severe haemophilia A. A French Multicentric Study.

The levels of anti-human and anti-porcine factor VIII inhibitors, measured in 63 severe haemophilia A patients, lay in the ranges of < 0.2-2,600 and < 0.2-1,300 Bethesda units per ml (BU/ml), respectively, with a median cross-reactivity of 33%. In 4 patients, human and porcine inhibitor levels were determined using both plasma, either human or porcine, and factor VIII concentrate, either very high purity human or porcine (Hyate:C). A good correlation between titres was found, whatever the source of factor VIII (plasma or concentrate). The cross-reactivity varies from 0 to over 100%, indicating that the evaluation of both human and porcine inhibitors should be mandatory before any treatment with Hyate:C. Results show that of the 46 patients with human inhibitor of more than 5 BU/ml, 21 (46%) with a low porcine inhibitor (< 5 BU/ml) could benefit from Hyate:C.

[Anti-HCV and recipients: situation in hemophiliacs in 1991]. / Anti-VHC et receveurs: situation chez les hémophiles en 1991.

Sera from 273 French haemophiliacs who had received non viral inactivated concentrates, were tested for antibodies to HCV by first and second generation assays. Antibodies to HCV were detected in 66% of the sera by the first generation assays (anti-C 100-3) reaching 100% by the second generation assays. None of the 53 patients only exposed to solvent-detergent treated Factor VIII or IX concentrates had HCV seroconversion. HCV core protein antibody was always detectable often as a single antibody in seropositive hemophilic patients.

Antibody to hepatitis C (anti C 100-3) in French hemophiliacs.

486 patients followed in four French hemophilia centres were tested for antibody to hepatitis C virus C100-3 recombinant protein. On samples collected in 1989, the overall incidence of anti-C 100-3 positivity was 66%. None of the 27 patients only exposed to solvent-detergent treated factor VIII or IX concentrates had C 100-3 antibodies. There was no difference according to the type of hemophilia nor to its severity. Serological follow-up from 1985 to 1989 was carried out on 51 patients. Two third of the C-100 3 paradoxically seronegative patients in 1989 were in fact positive for these antibodies within the last 5 years. They have lost their HCV antibodies as seen with the presently available C 100-3 test. Actually, as the virus has been already present at least for the last 10 years, (on 51 samples collected in 1979, the incidence of C-100-3 positivity was 78%), all treated patients may well have been in contact with HCV.

Induction of immune tolerance in patients with hemophilia A and inhibitors treated with porcine VIIIC by home therapy.

Home therapy with porcine factor VIIIC was safe and effective when administered to five hemophilic patients over periods of 8 1/2, 6, 4, 3 1/2, and 2 years. No significant transfusion reactions occurred. Before treatment with porcine factor VIIIC, all five had high-level, high-responding anti-human VIIIC inhibitors initially lacking anti-porcine factor VIIIC activity. Although specific anti-porcine VIIIC inhibitors arose in all patients, these were generally transient, and only one patient became refractory to treatment. We believe that porcine factor VIIIC is the treatment of choice in patients whose inhibitors do not cross-react. All five patients lost their original anti-human VIIIC inhibitors after starting treatment with porcine VIIIC, permitting the reintroduction of human VIIIC in three of them. There has been no recurrence of anti-human VIIIC inhibitor activity during 2 to 3 years of regular treatment with human VIIIC in these patients. This suggests that tolerance to human VIIIC has arisen as a result of treatment with porcine VIIIC. Porcine VIIIC may have a role in the desensitization of some factor VIIIC inhibitor patients.

Clinical and biological survey of haemophilia A and B patients infused with French heat-treated concentrates.

The efficiency of heat treatment procedures of factor VIII and factor IX concentrates, prepared from voluntary, non-paid donors by three French Blood Transfusion Centres, on the inactivation of HIV and non-A, non-B hepatitis (NANB) viruses was assessed. Some 43 patients (26 haemophilia A, 17 haemophilia B) were followed for at least 1 year by testing for HIV antibodies and alanine aminotransferase (ALT). No HIV seroconversion was observed indicating that heat treatment was completely efficient. Among 26 haemophiliacs, 6 (4 haemophilia A, 2 haemophilia B) presented an elevation in ALT, indicating only a 75% reduction of NANB viral contamination.

Long-term evaluation of HIV antigen and antibodies to p24 and gp41 in patients with hemophilia. Potential clinical importance.

To investigate the relation between human immunodeficiency virus (HIV) antigenemia and clinical manifestations of HIV infections, we studied 96 patients with hemophilia who were positive for HIV antibody, for a median of 34 months. Every 4 to 10 months a clinical and laboratory examination was performed and serum samples were tested for three HIV markers: HIV antigen, antibody to p24, and antibody to gp41. Twenty-two subjects (23 percent) were found to be positive for HIV antigen: 8 were positive upon entry and remained so (Group 1), and 14 became positive during the study, 4 to 26 months after HIV antibody appeared (seroconversion), 13 of whom remained positive for HIV antigen (Group 2). Most subjects positive for HIV antigen had low or undetectable titers of antibody to p24, whereas the antibody titer to gp41 remained high. In Group 2, patients with low p24 antibody titers had further decreases in their titers before or at the time HIV antigen appeared. Once present, HIV antigen persisted and tended to increase in concentration. In contrast to Group 3 (negative for HIV antigen, low anti-p24 titer) and 4 (negative for HIV antigen, high anti-p24 titer), the groups positive for HIV antigen had significantly higher incidences of acquired immunodeficiency syndrome (P = 0.05), immunodeficiency-related infections (P less than 0.001), and immune thrombocytopenia (P = 0.001), and had more severe disease as measured by the Walter Reed staging system (P less than 0.001). In this study, HIV antigen appeared to be a better predictive marker of HIV-related complications than the absolute T4+ count. These results suggest that HIV antigenemia indicates a poor clinical prognosis.

Synovectomy of the elbow in young hemophilic patients.

Synovectomy of twenty-three elbows was done in eighteen patients, eight to twenty-five years old, who had severe hemophilia and were followed for eighteen to seventy months. Episodes of bleeding recurred in four elbows, and moderate pain persisted in three. A significant improvement in mobility was observed for pronation-supination in nine elbows and for flexion-extension in fourteen. No radiographic evidence of arthritis was seen. Synovectomy of the elbow, performed through a single lateral incision, appears to be a valuable surgical procedure in hemophiliacs in whom non-operative treatment has failed, and resection of the radial head should be done in adults when there is moderate or severe damage to the cartilage of the radial head.

[Articular and muscular hemorrhages in hemophilia A with anti-factor VIII antibodies. Treatment with selected batches of PPSB (factor IX concentrate)]. / Hémorragies articulaires et musculaires des hémophiles A avec anticorps anti-facteur VIII. Traitement par des lots sélectionnés de PPSB (concentré de facteur IX).

Over a 10-month period, 65 bleeding episodes in 14 hemophilia A patients with anti-Factor VIII antibodies were treated with a non-activated Factor IX concentrate (PPSB). A single dose of 58-102 U/kg of Factor IX (average 80 U/kg) was used in 51 hemarthroses, 13 muscle hematomas and one dental bleed. Overall clinical results were satisfactory in 51% of cases. Forty nine per cent of acute hemarthroses were clinically improved. Safety tests were unchanged and no significant elevation of anti-VIII: C titers was recorded. These preliminary results ae similar to those obtained with single doses of activated prothrombin complex concentrates given to the same patients (Autoplex and FEIBA).

Non-A, non-B hepatitis in hemophilic patients with inhibitor treated with activated prothrombin complex concentrates: lack of correlation with an antigen possibly related to non-A, non-B hepatitis.

A population of 30 severe hemophilia-A patients with antibodies to factor VIII, treated with Autoplex since 1980, experienced a 30% incidence of non-A, non-B (NANB) hepatitis. 8 of the 9 patients affected had clinical signs of hepatitis and 7 had ALT levels in excess of 200 IU/l; the mean incubation time was 13 days. Only 5 of the 26 lots of Autoplex used were possibly transmitting the infective agent. An ELISA test to detect an antigen (DS-Ag) possibly related to NANB hepatitis was used to screen hemophilia-A and B patients. Its incidence was lower in patients treated less than 5 times a year (7.9%) than in patients treated over 15 times a year (25-27%) with locally prepared blood derivatives. Following treatment with Autoplex, the incidence of DS-Ag in inhibitor patients increased significantly (50%). In this last population, DS-Ag was shown to be unrelated to the NANB hepatitis observed. Although no direct evidence could be given, Autoplex was likely to transmit both the agent responsible for short incubation NANB hepatitis and DS-Ag.

Absence of anamnestic response after transfusion of washed red blood cells in haemophilia A patients with antibody to factor VIII.

Washed red blood cells (WRC) have been used for replacing the blood loss in haemophilia A patients with antibody to Factor VIII. Levels of VIII coagulant activity (VIII:C), VIII coagulant antigen (VIII:CAg) and VIII related antigen (VIIIR:Ag) have been measured during the different steps of the preparation of WRC. The amount of VIII:CAg decreases very rapidly after washing and both are undetectable in the final product. These results were correlated with the absence of anamnestic response in 10 haemophilia A patients with inhibitor known as high responders.

Circulating immune complexes and complement levels in hemophilic children.

Immune complexes and complement levels were assayed in sera from a group of 69 hemophilic children. Using the Raji cell radioimmune assay and the C1q binding assay, abnormally high levels of circulating immune complexes were rarely found in the group of hemophiliacs which did not differ statistically from the control population. These results do not exclude the presence of low and transient levels of immune complexes in the circulation, but indicate that hemophiliacs are not exposed to increased immune complex loads similar to those found in immune complex diseases. By contrast frequent abnormalities of the complement system were found. Complement levels were elevated in a large percentage of patients, reaching statistical significance for C3, C4, C5, Factor B and Properdin. Levels of the C3 breakdown product C3d were significantly raised suggesting intravascular complement activation. The significance of these abnormalities is discussed in relation to perfusion of Factor VIII preparations.

In vitro and in vivo characterization of factor VIII preparations.

An in vitro and in vivo comparison of nine commercial and noncommercial factor VIII preparations was made. These consisted of one lyophilized cryoprecipitate, four intermediate (IPC) and four high purity concentrates (HPC). Protein, fibrinogen, factor VIII complex, IgG, IgM and anti-A and B alloagglutinins levels were measured. These three qualities of product were defined by two ratios: units of F VIII:C per mg of protein and per mg of fibrinogen. They were, respectively, less than 0.05 and less than 1 in cryoprecipitate, 0.5--1 and 1--3 in IPC, and greater than 1 and greater than 3 in HPC. The F VIII:C/F VIII:AG ration ranged from 0.3 to 0.6 and the F VIII:C/F VIII:VWF ratio was always lower than 1. Varying titers of alloagglutinins were found, unrelated to either IgG or IgM levels. Seven of these preparations were injected into several classical hemophilia A patients for treatment of minor hemorrhages. The peak of F VIII:C activity was always found 1 h postinjection. The F VIII:C recovery ranged from 80 to 140% and the half-life from 8 to 15 h. No significant difference was found among these products and the clinical efficacy was similar.