Development of a novel automated screening method for detection of FVIII Inhibitors.

INTRODUCTION: Factor VIII activity is routinely determined by measuring the activated partial thromboplastin time (aPTT) of a patient plasma sample and determining percent activity from a standard curve. To maximize the detection of a clotting factor inhibitor, a subjective assessment of parallelism of a patient curve compared with a standard curve is performed. We developed and validated an automated objective method to assess parallelism as a rapid screening tool for detection of an inhibitor to factor VIII during routine FVIII assays. METHODS: We performed FVIII assays on a subset of FVIII-deficient patients with hemophilia A with and without inhibitors. Utilizing a ratio of the slopes from parallelism curves obtained by an independent Microsoft excel program in patients compared with a normal standard curve, we determined a cutoff ratio predictive for presence of an inhibitor. RESULTS: A cutoff ratio of patient to control slopes of <0.45 for the detection of an inhibitor to FVIII was 100% sensitive and 91.6% specific, with a positive predictive value of 92.3% and a negative predictive value of 100%. CONCLUSION: Utilizing a ratio of the slopes from parallelism curves in patients with and without an inhibitor, we developed and validated a rapid, automated, and objective method to assess parallelism as an added screening tool for detection of an inhibitor to factor VIII during routine FVIII assays on a STAGO-based coagulation platform. This simple automated method has the potential to detect inhibitors to other clotting factors.

Safety and efficacy of BAY 94-9027, a prolonged-half-life factor VIII.

Essentials Recombinant factor VIII BAY 94-9027 conjugates in a site-specific manner with polyethylene glycol. BAY 94-9027 was given to patients with severe hemophilia A as prophylaxis and to treat bleeds. BAY 94-9027 prevented bleeds at dose intervals up to every 7 days and effectively treated bleeds. BAY 94-9027 treatment was mainly well tolerated and no patient developed factor VIII inhibitors. Click to hear Dr Tiede's perspective on half-life extended factor VIII for the treatment of hemophilia A SUMMARY: Background BAY 94-9027 is a B-domain-deleted prolonged-half-life recombinant factor VIII (FVIII) that conjugates in a site-specific manner with polyethylene glycol. Objective Assess efficacy and safety of BAY 94-9027 for prophylaxis and treatment of bleeds in patients with severe hemophilia A. Patients/methods In this multinational, phase 2/3, partially randomized, open-label trial, men aged 12-65 years with FVIII < 1% and ≥ 150 exposure days to FVIII received BAY 94-9027 for 36 weeks on demand or prophylactically at intervals determined following a 10-week run-in period on 25 IU kg-1 body weight two times per week. Patients with > 1 bleed during the run-in subsequently received 30-40 IU kg-1 two times per week; patients with ≤ 1 bleed were eligible for randomization to every-5-days (45-60 IU kg-1 ) or every-7-days (60 IU kg-1 ) prophylaxis (1 : 1) for 26 additional weeks until randomization arms were filled. Patients who were eligible but not randomized continued twice-weekly prophylaxis. The primary efficacy outcome was annualized bleeding rate (ABR). Results The intent-to-treat population included 132 patients (prophylaxis, n = 112; on demand, n = 20). Median ABR (quartile [Q1; Q3]) for patients treated two times per week who were not eligible for randomization (n = 13) improved after dose increase (17.4 [14.3; 26.0] to 4.1 [2.0; 10.6]). Median ABR for patients randomized to every-5-days treatment (n = 43) was 1.9 (0; 4.2), similar to patients eligible for randomization but who continued treatment two times per week (n = 11). Median ABR for 32/43 patients (74%) who continued every-7-days prophylaxis until study end was 0.96 (0.0; 4.3). Six hundred and thirty-six of 702 bleeds (90.6%) were controlled with ≤ 2 infusions. No patient developed a FVIII inhibitor. Conclusions BAY 94-9027 prevented bleeding across three individually tailored dose regimens and was effective for treatment of bleeds.

Evaluation of von Willebrand factor phenotypes and genotypes in Hemophilia A patients with and without identified F8 mutations.

BACKGROUND: Hemophilia A (HA) is an X-linked bleeding disorder caused by a deficiency in factor VIII (FVIII). von Willebrand disease (VWD) is characterized by a quantitative or qualitative defect in von Willebrand factor (VWF). Patients with VWD with severely low VWF or VWD Type 2N (VWD2N), a VWD subtype distinguished by defective VWF binding to FVIII, may have reduced FVIII levels secondary to their VWD. These patients superficially resemble patients with HA and pose a potential for misdiagnosis. OBJECTIVES: To investigate the unexplained cause of bleeding in HA patients without known FVIII mutations by assessing plasma VWF antigen (VWF:Ag), FVIII binding capacities and VWF genotypes. PATIENTS/METHODS: Thirty-seven of 1027 patients with HA studied as part of the Hemophilia Inhibitor Research Study lacked identifiable F8 mutations. These patients (cases) and 73 patients with identified F8 mutations (controls) were evaluated for VWF:Ag, a patient's VWF capacity to bind FVIII (VWF:FVIIIB) and VWF sequence. RESULTS: Four cases had VWF:Ag < 3 IU dL(-1) and VWF mutations consistent with Type 3 VWD. Six cases and one control were heterozygous for mutations previously reported to cause Type 1 VWD (VWD1) (n = five cases and one control) or predicted to be deleterious by Polyphen2 and SIFT prediction tools (n = 1 case). One control had VWF:Ag < 30 IU dL(-1) and seven patients (four cases and three controls), including two cases who were heterozygous for a known VWD2N mutation, had reduced VWF:FVIIIB. CONCLUSIONS: These data emphasize that some patients diagnosed with HA require VWF assessments in order to achieve a comprehensive diagnosis and an optimal treatment strategy.

Correlates of high hepatitis C virus RNA load in a cohort of HIV-negative and HIV-positive individuals with haemophilia.

Hepatitis C virus (HCV) treatment failure and disease progression are more likely with high HCV-RNA load. Correlates of high HCV-RNA load in individuals with haemophilia are largely unknown. Among 1266 interferon naïve HCV-infected individuals with haemophilia, we compared those with high (> 2 x 106 HCV-RNA copies/mL) to lower viral load, overall and stratifying on HIV co-infection status using logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). Overall, high HCV load was independently associated with longer duration of HCV infection (P(trend)=0.0001), body mass index ≥ 25 kg/m² (OR=1.4, 95% CI=1.1-1.9), and HIV co-infection (OR=1.4, 95% CI=1.0-1.8). Among 795 HIV-negative participants, high HCV-RNA load was associated with older age at HCV acquisition (OR=1.9 for > 15 years vs ≤ 2 years, P(trend)=0.008), and lower AST/platelet ratio (P(trend)=0.01), in addition to longer duration of HCV infection (P(trend)=0.0008), and body mass index ≥ 25 kg/m² (OR=1.6, P=0.005). Among 471 HIV-positive individuals, anti-retroviral therapy (ART) was the only variable associated with high HCV-RNA load (OR=1.8, CI=1.1-2.9 for combination ART; OR=1.8, CI=0.9-3.4, for other ART vs no treatment). High HCV-RNA load with haemophilia is more likely with longer duration of infection, older age at infection, higher body mass index, and antiretroviral therapy. These findings may help identify individuals at increased risk of HCV treatment failure and progression to end-stage liver disease.

Upper gastrointestinal bleeding in haemophiliacs: incidence and relation to use of non-steroidal anti-inflammatory drugs.

This multicentre study sought to estimate the incidence of upper gastrointestinal (UGI) bleeding in haemophiliacs and its relationship to use of non-steroidal anti-inflammatory drugs (NSAIDs). Cox models were used to estimate relative hazards (RH) with 95% confidence intervals (CI) for postulated risk factors. Conditional logistic regression and stored sera were used to assess UGI bleeding risk with Heliobacter pylori seropositivity in cases compared with closely matched controls. During a mean of 17.4 months (range 2-34), 2285 participants, ages 13-89 (mean 36.5) were followed for 3309 person-years (py). Forty-two experienced a UGI bleeding event (incidence 1.3 per 100 py), most from ulcer (11), gastritis (four), varices (five) and Mallory Weiss tears (eight). RH was significantly increased with traditional NSAID use for <1 month (OR: 3.66; 95% CI: 1.1-11.9), but not with coxibs use. RH was significantly and independently increased with age >46 years (3.5; 95% CI: 1.1-10.6) and hepatic decompensation (4.4; 95% CI: 1.7-11.6). Likelihood of bleeding was substantially but not significantly increased (OR: 4.6; 95% CI: 0.3-83.9) with H. pylori seropositivity. These findings suggest that coxibs are a safer alternative than traditional NSAIDs in the treatment of haemophilic arthropathy.

Knee and hip arthroplasty infection rates in persons with haemophilia: a 27 year single center experience during the HIV epidemic.

Total joint replacement (TJR) is an option for the management of chronic haemophilic arthropathy. Because surgery is technically challenging, there is a high rate of deep prosthetic infections, particularly in human immunodeficiency virus (HIV)-infected individuals. We determined the incidence of deep infection rates following total knee and hip arthroplasties in HIV-seropositive and HIV-seronegative persons with haemophilia. Fifty-one primary joint replacements were performed on 32 patients seen at a regional comprehensive haemophilia care center from 1975 to 2002. Thirty prostheses were placed in patients who were HIV-seropositive prior to surgery (n = 14) or seroconverted later (n = 16). Median age at the time of surgery was 33 years (range: 20-61) among 19 HIV-seropositive patients and 35 years (range: 26-74) among 13 HIV-negative patients. Median duration of follow-up was 83 months (range: 2-323). Rate of primary joint infection per artificial joint-year by HIV status was compared by Poisson regression. Main outcome measures were the incidence of primary replacement joint infections by HIV status. Deep infections developed in five (9.8%) of 51 replacement joints. There were two infections during 204.15 joint-years without HIV infection and three infections during 205.28 joint-years with HIV infection. The incidence rate of joint infection (0.98 vs. 1.46 per 100 joint-years) was not increased with HIV (relative risk, RR: 1.49, 95% CI: 0.25-8.93, P = 0.66). We conclude that HIV infection is not a contraindication to knee or hip replacement arthroplasty in the appropriate clinical setting.

Liver biopsy in patients with inherited disorders of coagulation and chronic hepatitis C.

Liver biopsy plays a pivotal role in the management of patients with a variety of liver diseases, including chronic hepatitis C virus. The major risk of the procedure is the potential for significant haemorrhagic complications. Although the data are limited, the procedure does not appear to pose excessive risk to the patient with inherited disorders of coagulation, provided that adequate haemostasis can be achieved prior to the liver biopsy. This requires close coordination of care between the hepatologist and the haematologist. Indications for liver biopsy should be the same in patients with haemophilia as in other populations.

Viral clearance occurs very early during the natural resolution of hepatitis C virus infection in persons with haemophilia.

We studied spontaneous hepatitis C virus (HCV) RNA clearance in 12 haemophilic patients. In their earliest anti-HCV positive samples, HCV RNA was undetectable in eight patients (66%), positive by polymerase chain reaction (PCR) but negative by branched-DNA (bDNA) in three others, and quantifiable by bDNA (4839 IU/mL) in only one patient. In contrast, in earliest anti-HCV positive samples from eight matched controls who had persistent viremia, HCV RNA was quantifiable by bDNA in seven (P = 0.0008) and at higher levels (range 4644-678 515 IU/mL; median 43 532 IU/mL). From initial HCV infection, HCV RNA cleared in 7 months or less in four patients and in 1-2 years in six others. HCV persisted for 5 years before clearance in the absence of repeated exposure in one patient. We conclude that HCV clearance usually but not always occurs within 1-2 years after infection and is more likely in those with lower than in those with higher early viral loads.

Activity of HIV-1 integrases recovered from subjects with varied rates of disease progression.

We recently described 102 HIV-1 integrase sequences that were amplified from blood cells or plasma obtained up to 18 years ago from 5 hemophiliacs who later died of AIDS and 5 hemophiliacs subsequently classified as slow or nonprogressors ( J Acquir Immune Defic Syndr Hum Retrovirol 1998;19:99-110). Although the region of the HIV-1 genome that encodes integrase was highly conserved, none of the deduced protein sequences of the patient-derived enzymes matched that of the clade B consensus or standard laboratory integrases. To test the hypothesis that the activity of HIV-1 integrases prevalent within an infected person contributes to the rate of disease progression, we have now expressed and purified these proteins and compared them in various assays. Most of the 75 unique full-length integrase proteins from the 102 clones were enzymatically active. Comparison of proteins derived from samples obtained soon after infection showed that the specificity and extent of viral DNA processing and the amount of DNA joining (the two biologically relevant activities of integrase) did not differ between the two groups of patients. In addition, the relative usage of alternative nucleophiles for processing and the amount of nonspecific nicking catalyzed by the proteins were indistinguishable between the patient groups. Although the patient-derived enzymes often exhibited different patterns of target site preferences compared with the laboratory integrase, there was no correlation with clinical course. Thus, the activities of HIV-1 integrases prevalent within these infected individuals, at least as reflected by standard assays, did not influence or predict the rate of disease progression.

Lack of association of hepatitis C virus load and genotype with risk of end-stage liver disease in patients with human immunodeficiency virus coinfection.

In hepatitis C virus (HCV) infection, virus load and the risk for HCV-related end-stage liver disease (ESLD) are increased among persons with human immunodeficiency virus (HIV) coinfection. To clarify these relationships, 42 hemophilic patients who developed ESLD and random samples from 164 hemophilic patients with HCV infection alone and 146 with HCV-HIV coinfection were tested for HCV load and genotype. HCV genotype was unrelated to HIV and age. In contrast, HCV load was higher with older age (P(trend)=.0001) and with HIV coinfection (6.2 vs. 5.9 log(10) genome equivalents/mL, P=.0001). During 16 years of follow-up of dually infected patients, ESLD risk was unrelated to HCV load overall (P(trend)=.64) or separately to HCV genotype 1 and genotypes 2 or 3 (P(trend)> or =.70). Irrespective of virus load, incidence of ESLD was marginally increased 2-fold (95% confidence interval, 0.8-5.6) with HCV genotype 1. Understanding the discordance between HCV load and ESLD, despite HIV's link to each of these, may help clarify the pathogenesis of HCV-related disease.

Intra- and interlaboratory variabilities of results obtained with the Quantiplex human immunodeficiency virus type 1 RNA bDNA assay, version 3.0.

Normal assay variation associated with bDNA tests for human immunodeficiency virus type 1 (HIV-1) RNA performed at two laboratories with different levels of test experience was investigated. Two 5-ml aliquots of blood in EDTA tubes were collected from each patient for whom the HIV-1 bDNA test was ordered. Blood was stored for no more than 4 h at room temperature prior to plasma separation. Plasma was stored at -70 degrees C until transported to the Central Pennsylvania Alliance Laboratory (CPAL; York, Pa.) and to the Hershey Medical Center (Hershey, Pa.) on dry ice. Samples were stored at < or =-70 degrees C at both laboratories prior to testing. Pools of negative (donor), low-HIV-1-RNA-positive, and high-HIV-1-RNA-positive plasma samples were also repeatedly tested at CPAL to determine both intra- and interrun variation. From 11 August 1999 until 14 September 2000, 448 patient specimens were analyzed in parallel at CPAL and Hershey. From 206 samples with results of > or =1,000 copies/ml at CPAL, 148 (72%) of the results varied by < or =0.20 log(10) when tested at Hershey and none varied by >0.50 log(10). However, of 242 specimens with results of <1,000 copies/ml at CPAL, 11 (5%) of the results varied by >0.50 log(10) when tested at Hershey. Of 38 aliquots of HIV-1 RNA pool negative samples included in 13 CPAL bDNA runs, 37 (97%) gave results of <50 copies/ml and 1 (3%) gave a result of 114 copies/ml. Low-positive HIV-1 RNA pool intrarun variation ranged from 0.06 to 0.26 log(10) while the maximum interrun variation was 0.52 log(10). High-positive HIV-1 RNA pool intrarun variation ranged from 0.04 to 0.32 log(10), while the maximum interrun variation was 0.55 log(10). In our patient population, a change in bDNA HIV-1 RNA results of < or =0.50 log(10) over time most likely represents normal laboratory test variation. However, a change of >0.50 log(10), especially if the results are >1,000 copies/ml, is likely to be significant.

Characterization of high-risk HIV-1 seronegative hemophiliacs.

Mechanisms that protect most high-risk HIV-1 seronegative (HRSN) persons are not well understood. Among hemophiliacs from the Multicenter Hemophilia Cohort Study who remained HIV-1 seronegative despite a high (94%) risk for acquisition of HIV-1 infection, only 7/43 were homozygous for the protective CCR5 Delta32 polymorphism. Among the remainder, neither CCR5 density nor beta-chemokine production, nor in vitro susceptibility to infection with the HIV-1 isolate JR-FL could distinguish HRSN hemophiliacs from healthy controls. When compared to lymphocytes of healthy controls not at risk for HIV-1 infection, diminished spontaneous lymphocyte proliferation was seen in lymphocytes of HRSN hemophiliacs as well as in lymphocytes of hemophiliacs not at risk for HIV-1 infection. Surprisingly sera/plasmas obtained from high-risk HIV-1 seropositve hemophiliacs prior to seroconversion more often contained alloreactive antibodies than date-matched sera/plasmas obtained from HRSN hemophiliacs. Thus alloreactivity may predispose to acquisition of HIV-1 infection after parenteral exposure.

Hepatitis C viral clearance and antibody reactivity patterns in persons with haemophilia and other congenital bleeding disorders.

We studied hepatitis C virus (HCV) clearance and antibody reactivity patterns in a cohort of 100 haemophiliacs exposed to unsterilized blood products, of whom 25 were antiHCV negative and 75 were antiHCV positive [49 human immunodeficiency virus (HIV) negative and 26 HIV positive]. HCV RNA was measured by the 2.0 bDNA assay and an 'in-house' polymerase chain reaction assay. Antibody reactivity patterns were examined using a recombinant immunoblot assay (RIBA). Prior HCV infection was found in two (8%) of 25 antiHCV negative patients. HCV viraemia persisted in all 26 antiHCV+ patients who were coinfected with HIV. HCV RNA clearance was found in 12 (25%) of 49 antiHCV+, HIV- patients. Viral clearance was associated with younger current age (P < 0.01) and age at infection (P < 0.001), but not with duration of infection or with dose or frequency of clotting factor use. RIBA ratios reflecting an index of each patient's overall reactivity to four HCV epitopes were significantly lower in those with viral clearance (P < 0.0001). Over a period of 15 years, those with viral clearance demonstrated significant loss of reactivity to the NS3, NS4 and NS5 epitopes, while those with viral persistence demonstrated relatively stable reactivities to all epitopes. We conclude that spontaneous HCV RNA clearance in haemophiliacs is age-related and is unlikely to occur in those coinfected with HIV. The loss of antibody reactivity for some epitopes, especially c22 (core), may be a marker for the natural resolution of chronic HCV infection.

Increased liver decompensation risk with atypical hepatitis C virus antibody levels.

Knowledge of serum markers of liver decompensation would facilitate care of patients with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections. HCV load and anti-c33c and anti-NS5 levels did not distinguish 28 HCV- and HIV-positive predecompensation patients from 28 matched control patients, whereas more patients than controls had high anti-c100(p) and low anti-c22(p). In multivariate analysis, decompensation was associated with high anti-c100(p) titer (>/=1:4050; odds ratio [OR], 3. 4; 95% confidence interval [CI], 1.1-11.5) and low anti-c22(p) (<1:36,450; OR, 3.0; 95% CI, 1.0-10.2) and with antibody band strength at 1:50 dilution (anti-c100[p] OR, 7.0; 95% CI, 1. 7-48.9; anti-c22[p] OR, 7.1; 95% CI, 1.7-49.2). With high anti-c100(p) or low anti-c22(p), sensitivity for decompensation was 86%-96% and specificity was 21%-36%; with both markers, sensitivity was 29%-32% and specificity was 93%-96%. Although the mechanisms for these associations are unknown, if these findings are verified in other populations, anti-c100(p) and anti-c22(p) might be valuable surrogate markers for liver decompensation risk.

Phenotypic expressions of CCR5-delta32/delta32 homozygosity.

OBJECTIVE: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-delta32/delta32 homozygous genotype has phenotypic expressions other than those related to HIV-1. DESIGN: Study subjects were white homosexual men or men with hemophilia who were not infected with HIV-1. In this study, 15 CCR5-delta32/delta32 homozygotes were compared with 201 CCR5 wild-type (+/+) subjects for a wide range of clinical conditions and laboratory assay results ascertained during prospective cohort studies and routine clinical care. CCR5-delta32 genotype was determined by polymerase chain reaction, followed by single-stranded conformational polymorphism analysis. RESULTS: Hypertension and conditions attributable to hemophilia were the only diagnoses frequently found in clinical records of CCR5-delta32/delta32 study subjects. Based on blood pressure measurement and treatment history, CCR5-delta32/delta32 homozygotes had a 2.8-fold higher prevalence of hypertension than age-matched CCR5-+/+ study subjects (95% confidence interval [CI], 1.2-6.4; p = .01); none of the homozygotes had severe hypertension. Hematologic measures were generally similar across the genotypes, but total lymphocyte counts were approximately 20% higher in CCR5-delta32/delta32 study subjects than in CCR5-+/+ study subjects (p < .05). Among patients with hemophilia who were infected with hepatitis C virus (HCV), mean alanine aminotransferase levels were 117% higher among CCR5-delta32/delta32 homozygotes (p < .05), but serum HCV levels did not differ by CCR5-delta32 genotype. CCR5-delta32/delta32 homozygous study subjects had a lower prevalence of antibodies to measles virus than those with other genotypes, but this association was not confirmed in a group of blood donors. The prevalence of antibodies to nine other common viruses, HBV, and HCV was not related to CCR5 genotype. CONCLUSIONS: CCR5-delta32/delta32 homozygotes are generally similar to wild-type persons. Confirmatory investigations are required to determine whether hypertension, increased lymphocyte counts, and higher hepatic enzyme levels in the presence of HCV infection represent true phenotypic expressions of this genotype. CCR5-delta32/delta32 homozygosity does not provide broad protection against viral infections.

Chronic hepatitis C virus infections in leukemia survivors: prevalence, viral load, and severity of liver disease.

The natural history of chronic hepatitis C (HCV) infections in long-term leukemia survivors has not been well characterized. We studied the prevalence of HCV infections, measured HCV RNA levels, and evaluated the severity of liver disease in patients with leukemia who achieved long-term remissions after intensive chemotherapy or bone marrow transplantation (BMT). HCV antibody tests were performed by the enzyme-linked immunosorbent assay (ELISA) and positive tests confirmed by the recombinant immunoblot assay (RIBA). HCV RNA levels were measured by the branched DNA (bDNA) assay. Seventy-five leukemia survivors with 25 or more blood donor exposures were identified. Nine (12%) were anti-HCV positive. All were infected before 1992 when second generation HCV screening tests were implemented. Mean HCV RNA levels were 10.3 x10(6) eq/mL versus 3.2 x 10(6) eq/mL (P =.056) in a control group of 20 anti-HCV positive immunocompetent individuals of comparable age who were infected twice as long (17.8 +/- 6.5 years v 9.0 +/- 4.4 years in leukemia survivors, P =.001). Liver biopsies were performed on six of the nine anti-HCV positive leukemia survivors. All showed at least moderate portal inflammation and half had evidence of bridging fibrosis. We conclude that viral loads in anti-HCV positive leukemia survivors are markedly higher than in immunocompetent controls. Our results suggest that long-term leukemia survivors with chronic HCV may have more rapidly progressive liver disease than has been previously recognized.

Prevalence and changes in hepatitis C virus genotypes among multitransfused persons with hemophilia. The Multicenter Hemophilia Cohort Study.

The purpose of this study was to determine hepatitis C virus (HCV) genotypes and their relationship to HCV RNA levels over time in a cohort of multitransfused hemophiliacs. Following reverse transcription and polymerase chain reaction amplification of HCV RNA, the product DNAs were genotyped by using the line probe assay. HCV RNA was quantified by the branched-chain DNA assay. Genotyping was done on 109 serum samples from 32 subjects. Genotype 3a had the highest prevalence (41%), followed by genotypes 1a (31%) and 1b (13%). Changes in genotypes were observed in 18 (58%) of the subjects >3-15 years of age. Changes were more common in human immunodeficiency virus (HIV)-positive subjects (13/17) than in HIV-negative subjects (5/15) (P=.014). HCV RNA increased 30-fold in HIV-positive subjects whose genotypes changed. Consensus nucleotide sequencing confirmed genotype changes in 2 patients. We conclude that genotype changes are common in hemophiliacs with chronic HCV, particularly in those who are coinfected with HIV.