Incidence of hypertension in people with HIV who are treated with integrase inhibitors versus other antiretroviral regimens in the RESPOND cohort consortium.

OBJECTIVE: To compare the incidence of hypertension in people living with HIV receiving integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART) versus non-nucleoside reverse transcriptase inhibitors (NNRTIs) or boosted protease inhibitors (PIs) in the RESPOND consortium of HIV cohorts. METHODS: Eligible people with HIV were aged ≥18 years who initiated a new three-drug ART regimen for the first time (baseline), did not have hypertension, and had at least two follow-up blood pressure (BP) measurements. Hypertension was defined as two consecutive systolic BP measurements ≥140 mmHg and/or diastolic BP ≥90 mmHg or initiation of antihypertensives. Multivariable Poisson regression was used to determine adjusted incidence rate ratios (aIRRs) of hypertension, overall and in those who were ART naïve or experienced at baseline. RESULTS: Overall, 4606 people living with HIV were eligible (INSTIs 3164, NNRTIs 807, PIs 635). The median baseline systolic BP, diastolic BP, and age were 120 (interquartile range [IQR] 113-130) mmHg, 78 (70-82) mmHg, and 43 (34-50) years, respectively. Over 8380.4 person-years (median follow-up 1.5 [IQR 1.0-2.7] years), 1058 (23.0%) participants developed hypertension (incidence rate 126.2/1000 person-years, 95% confidence interval [CI] 118.9-134.1). Participants receiving INSTIs had a higher incidence of hypertension than those receiving NNRTIs (aIRR 1.76; 95% CI 1.47-2.11), whereas the incidence was no different in those receiving PIs (aIRR 1.07; 95% CI 0.89-1.29). The results were similar when the analysis was stratified by ART status at baseline. CONCLUSION: Although unmeasured confounding and channelling bias cannot be excluded, INSTIs were associated with a higher incidence of hypertension than were NNRTIs, but rates were similar to those of PIs overall, in ART-naïve and ART-experienced participants within RESPOND.

Retroperitoneal hematoma in COVID-19 patients - case series.

COVID-19 patients, particularly those with severe pulmonary involvement, are at an increased thromboembolic risk related, among various causes, to the cytokine storm and excessive activation of the coagulation cascade and platelets. Different intensity of anticoagulation for them is proposed, mainly with low molecular weight heparins (LMWHs); in a confirmed pulmonary embolism (PE) the therapeutic dose of LMWH is routinely used. Some authors suggest that hemorrhagic complications in COVID-19 patients are rare. At the same time, one can find reports on internal bleeding, including retroperitoneal hematoma (RPH) and other abdominal hematomas. CASE REPORTS: The authors describe 5 cases (3 of those aged more than 80 years) with giant RPHs and with moderate/severe COVID-19 pneumonia, treated before RPH diagnosis with different enoxaparin doses. The therapeutic dose was given to the male with verified PE limited to the segmental/subsegmental pulmonary arteries and initially to the female in whom echocardiography was strongly suggestive of PE, yet this diagnosis was excluded on CT angiography. In one patient, the enoxaparin dose was escalated from 40 mg bd to 60 mg bd after the D-dimer increase. Two patients had bleeding complications despite the enoxaparin dose restricted to 40 mg/daily or bd. Two males had a coexistent psoas hematoma while in only one female there was a coexistent femoral hematoma. RPHs occurred between day 4 and 14 of hospitalization and all were treated conservatively. Three patients who died were particularly charged, so their deaths were not merely directly associated with RPH, which was closely analyzed in one autopsy performed. The authors underline that the choice of anticoagulation intensity in patients with COVID-19 pneumonia without venous thromboembolism seems sometimes difficult but recent publications indicate the low prophylactic enoxaparin dose as an optimal option. Anticoagulation dose escalation based only on the D-dimer level may not be appropriate for certain patients; moreover, the D-dimer increase is commonly observed during internal bleeding.

Gender as a factor affecting NK cell activity in patients successfully treated for chronic hepatitis C with direct-acting antivirals.

Chronic hepatitis C (CHC) affects the activity of natural killer (NK) cells, but successful interferon- free treatment partially restores it. The goal of this study was to assess whether gender influences NK functionality. We examined 21 post-menopausal women and 24 men with CHC who were treated with direct-acting antivirals (DAA) and 33 healthy volunteers. Using flow cytometry, we analysed KIR2DS4, NKG2D, NKp30, KIR2DL2/DL3, NKG2A and TRAIL on the surface of NK cells. Intracellular granzyme B was also assessed and serum CXCL10 was quantified via ELISA. Overall, patients with CHC had higher expression of KIR2DS4, NKG2A, and NKp30 relative to the control group. Further, CHC patients had a lower percentage of NK cells among lymphocytes relative to the control group. After treatment, KIR2DS4, KIR2DL2/DL, NKG2A, TRAIL and NKp30 on NK cells were decreased whilst the percentage of NK cells and the expression of granzyme B and NKG2D increased. Prior to treatment, serum CXCL10 was elevated, but it was inhibited post-treatment. We observed gender-specific differences in the expression of KIR2DL2/DL3 (higher in women) and NKp30 (elevated in men) compared to CHC/control groups. After treatment, KIR2DL2/DL3, NKp30 and CXCL10 dropped only in the female group while granzyme B increased in the male group. In conclusion, the response of NK cells among men and women of post-menopausal ages with CHC differs. Our research may lead to more studies on the different nature of female and male immune systems in the context of HCV infection and treatment.

Exposure to hepatitis E virus in hemodialysis patients from west-central Poland.

Hepatitis E virus (HEV) causes travel-related but also locally acquired infections in industrialized parts of the world, including European countries. Food and blood transfusions are possible sources of transmission. Infections caused by zoonotic variants of the virus (particularly HEV-3) may progress to chronic liver disease in a nonnegligible proportion of immunocompromised people. The aim of this study was to assess the prevalence of serological markers of HEV infection in 189 patients on renal replacement therapy (RRT, currently on hemodialysis, HD) living in west-central Poland and to determine the factors related to HEV exposure in this group. Testing was carried out using commonly used commercial assays (Wantai Biological Pharmacy Enterprise Co, Beijing, China). Anti-HEV IgG was detected in 94 patients (49.7%); none of the participants had anti-HEV IgM or HEV Ag. Patients on RRT (HD) for less than 6 months were significantly more likely to be anti-HEV IgG-positive than dependent of RRT (HD) for more than half a year (80% vs 47%; P = .014). Exposure to HEV in patients from west-central Poland is frequent, but no clear sources of this infection have been identified. There were no serological features of ongoing liver disease caused by HEV in the study subjects.

Comparative Seroprevalence of Hepatitis A And E Viruses in Blood Donors from Wielkopolska Region, West-Central Poland.

The objective of the present study was to investigate the seroprevalence of HAV and HEV in Polish blood donors (BDs). One hundred and ten randomly selected healthy BDs, living in Wielkopolska Region were tested for anti-HAV IgG and anti-HEV IgG with commercial assays. The seroprevalence of anti-HAV was 11.8%; anti-HEV were detected in 60.9% of BDs (p < 0.0001). Consumption of risky food was more common in anti-HEV-positive BDs (59.1% vs. 33.3%; p = 0.01). Twelve out of 20 BDs (60%) with no history of travel abroad were exposed to HEV. Wielkopolska Region, Poland should be regarded as a new HEV infection-hyperendemic area in Europe.

Takotsubo cardiomyopathy triggered by influenza B.

Influenza is associated with a high prevalence of cardiac complications, including myocarditis and exacerbation of ischemic heart disease or heart failure (HF). However, only four cases of stress-induced takotsubo cardiomyopathy (TC), all of them triggered by virus A influenza, have been reported so far. Another two TC cases after anti-influenza vaccination are also available in the literature. The authors describe a new case of TC, this time provoked by influenza B. An 89-year-old female with a history of hypertension and chronic obstructive pulmonary disease (COPD) was admitted due to a fever (39oC), muscle aches and cough. Pneumonia was excluded in chest X-ray while the test for influenza confirmed virus B infection, so she was given oseltamivir. On the second day of hospitalization, she developed severe HF. ECG showed new negative T waves in inferior and anterolateral leads coexisting with a moderate troponin I and marked brain natriuretic peptide release, while echocardiography revealed left ventricular (LV) apical ballooning with decreased ejection fraction (EF 24%) and global longitudinal strain (GLS -8.1%). Symptomatic treatment of HF was initiated. The symptoms of influenza resolved after 5 days. LV function began to improve after 4 days and became normal after 6 days (EF 58%, GLS -18.1%). Despite an advanced age and the coexisting disorders (COPD, mild cognitive impairment, possible neoplastic disease), the patient was discharged in stable clinical condition on day 10. The authors conclude that in the evaluation of cardiac complications of influenza, TC should be taken into account.

Fatal course of takotsubo cardiomyopathy in a female with recurrent Clostridium difficile infection.

Among diverse triggering factors of stress-induced takotsubo cardiomyopathy (TC), a viral or bacterial infection is rarely observed. Sepsis is an exception, regardless of the etiologic pathogen, in which case an excess of catecholamines may result in acute left ventricular dysfunction. TC precipitated by Clostridium difficile infection (CDI) has been reported only in two patients so far. A CASE REPORT: The authors describe another case of TC triggered this time by recurrent C. difficile colitis which occurred in a 72-yearold female. Severe heart failure developed on the second day of a new episode of diarrhea. Echocardiography revealed apical ballooning, a typical form of TC, while the coronary arteries in coronary angiography were normal. Despite proper treatment of CDI, the course of the disease was fatal due to heart failure progression. In considerations of TC pathogenesis in the case presented, the impact of C. difficile toxins should be taken into account. One should remember about the potential extraintestinal complications of CDI, including sudden myocardial depression.

[Myopericarditis in a 23-year-old male with herpes zoster]. / Zapalenie miesnia serca i osierdzia u 23-letniego mezczyzny z pólpascem.

The varicella zoster virus (VZV) belongs to cardiotropic viruses, although the frequency of cardiac complications during VZV infection is low. Diagnosis of myocarditis or myopericarditis is rare during varicella - primary infection of VZV and sporadic in zoster - reactivation of latent VZV. Only few such cases have been described. The authors present a case of a 23-year-old male in whom clinical symptoms of myopericarditis developed a week after diagnosis of zoster that was localized in the left-upper part of the thorax. Retrosternal chest pain and fever were accompanied by ECG mimicking acute myocardial infarction. A dynamic pattern of troponin I release and slow normalization of ECG were observed. Serial echocardiography showed normal left ventricular function, transient changes in echogenicity of the interventricular septum and small pericardial effusion. In magnetic resonance imaging subepicardial and intramyocardial areas of late gadolinium enhancement were found. He was treated with intravenous acyclovir. No late sequels of the disease were observed.

Transmitted HIV drug resistance in antiretroviral-treatment-naive patients from Poland differs by transmission category and subtype.

OBJECTIVES: The surveillance of HIV-transmitted drug resistance mutations (t-DRMs), including temporal trends across subtypes and exposure groups, remains a priority in the current management of the epidemic worldwide. METHODS: A cross-sectional analysis of 833 treatment-naive patients from 9 of 17 Polish HIV treatment centres. Partial pol sequences were used to analyse drug resistance with a general time reversible (GTR)-based maximum likelihood algorithm used for cluster/pair identification. Mutation frequencies and temporal trends were investigated. RESULTS: t-DRMs were observed in 9% of cases (5.8% for NRTI, 1.2% NNRTI and 2.0% PI mutations) and were more common among heterosexually infected (HET) individuals (13.4%) compared with MSM (8.3%, P = 0.03) or injection drug users (IDUs; 2.9%, P = 0.001) and in MSM compared with IDUs (P = 0.046). t-DRMs were more frequent in cases infected with the non-B variant (21.6%) compared with subtype B (6.6%, P < 0.001). With subtype B a higher mutation frequency was found in MSM compared with non-MSM cases (8.3% versus 1.8% for IDU + HET, P = 0.038), while non-B variants were associated with heterosexual exposure (30.4% for HET versus 4.8% for MSM, P = 0.019; versus 0 for IDU, P = 0.016). Trends in t-DRM frequencies were stable over time except for a decrease in NNRTI t-DRMs among MSM (P = 0.0662) and an NRTI t-DRM decrease in HET individuals (P = 0.077). With subtype B a higher frequency of sequence pairs/clusters in MSM (50.4%) was found compared with HET (P < 0.001) and IDUs (P = 0.015). CONCLUSIONS: Despite stable trends over time, patterns of t-DRMs differed notably between transmission categories and subtypes: subtype B was associated with MSM transmission and clustering while in non-B clades t-DRMs were more common and were associated with heterosexual infections.

Seroprevalence of anti-HEV IgG in 182 Polish patients.

INTRODUCTION: Hepatitis E virus (HEV) infection is an emergent disease in developed countries. HEV seroprevalence in such areas significantly exceeds values expected when one considers infection with this virus only as a problem restricted to classical endemic regions. To date, no related data are available in Poland. In this study we aimed to obtain HEV seroprevalence data and compare them with similar data for hepatitis A virus (HAV) in Polish patients. MATERIAL/METHODS: From February 1st, 2013, to October 15th, 2013, we performed anti-HEV IgG (anti-HEV) tests (EIAgen HEV IgG Kit; Adaltis, Milano, Italy) in 182 patients (101 men and 81 women; 61 patients were HIV-positive) of one center in Poland, aged 19-85 (47.2 ± 14.2 years). RESULTS: We found a 15.9% seropositivity rate for anti-HEV (16.3% of the study population with an unequivocal test result) and 38.5% for anti-HAV. In 6 cases (3.4%), anti-HEV-positive persons had never travelled abroad. In contrast to HAV seroprevalence data, there was no significant difference in HEV seroprevalence between young adults (18-40 years) and older patients (p<0.0001 and p=0.0967, respectively). Anti-HEV were found in 21.3% of HIV-infected individuals. CONCLUSIONS: HEV infection may occur in Poland. Anti-HAV seropositivity among Polish patients is significantly higher than anti-HEV. In contrast to HAV, HEV seroprevalence is similar in younger and older patients. The clinical course of HEV infection in Polish citizens seems to be largely asymptomatic. Polish HIV patients may be more commonly exposed to HEV than similar individuals from other countries.

Pneumocystis pneumonia in children - the relevance of chemoprophylaxis in different groups of immunocompromised and immunocompetent paediatric patients.

INTRODUCTION: Pneumocystis jirovecii is an opportunistic pathogen causing pneumocystis pneumonia (PCP), a life-threatening infection, in immunocompromised patients. In this study, retrospective analysis of the presence of P. jirovecii DNA in different samples collected from children with suspected PCP was carried out. MATERIAL AND METHODS: Three hundred and six specimens [152 bronchoalveolar lavage (BAL) specimens, 80 blood specimens, 18 bronchial secretions (BS), 34 induced sputum samples, 10 endotracheal aspirates (ETA), and 12 other type samples] obtained from patients with suspected PCP were examined by real-time PCR. RESULTS: Forty (13.1%) patients were positive for P. jirovecii: 4 (7.7%) patients with malignancies, 3 (6.8%) transplant recipients, 15 (23.1%) other immunocompromised patients, and 18 (12.4%) immunocompetent patients. Pneumocystis jirovecii DNA was detected in 20.4% of BAL specimens, 11.1% of BS samples, 10% of ETA sample, 8.8% of induced sputum samples, and in 3.7% of blood samples. Comparing the frequency of the presence of P. jirovecii DNA between the group of children treated with PCP chemoprophylaxis (malignancy patients and transplant recipients) and a group of children not receiving this prophylaxis (other immunocompromised and immunocompetent children), we found that the occurrence of PCP was twice as high in the latter group of children (7.3% and 15.7%, respectively). CONCLUSIONS: Respiratory samples, such as BS, BAL, or ETA specimens, are the material of choice for the diagnosis of PCP. Due to high incidence of PCP in certain groups of immunocompetent and immunocompromised patients, besides cancer patients and transplant recipients, consideration of PCP prophylaxis is required in these groups as well.

[Clinical outcomes of superinfections with primary hepatotropic viruses in patients with chronic hepatitis B or C]. / Nastepstwa kliniczne nadkazen wirusami pierwotnie hepatotropowymi u chorych na przewlekle zapalenia watroby typu B lub C.

Chronic hepatitis B and C are among most important problems in contemporary hepatology. Natural history of the disease can be changed as a result of superinfection with other primary hepatotropic viruses. Clinical consequences of such events are uncommon subjects of clinical reports. Acute viral hepatitis occurring in HBV- or HCV-infected patients can result in severe exacerbation of liver disease, including acute liver failure; sometimes progression of liver disease toward liver cirrhosis is observed; HBV and/or HCV clearance is also possible. Because of potentially severe outcomes of superinfections, prevention of such events based on vaccinations and education about the risk related with additional infections should be implemented in the management of patients with chronic viral hepatitis B and C.

Hepatitis C virus load and expression of a unique subset of cellular genes in circulating lymphoid cells differentiate non-responders from responders to pegylated interferon alpha-ribavirin treatment.

Based on investigations of liver biopsy material, certain cellular genes have been implicated as correlates of success or failure to interferon alpha-ribavirin (IFN/RBV) therapy against hepatitis C. The current study aimed at determining whether expression of host genes thought to be relevant to HCV replication in the liver would be correlated with HCV infection status in peripheral blood mononuclear cells (PBMCs) and also with patient responsiveness to IFN/RBV treatment. Therefore, PBMCs from patients with chronic hepatitis C responding (n = 35) or not (n = 49) to IFN/RBV and from healthy controls (n = 15) were evaluated for HCV RNA load and cellular gene expression. Non-responders had 3- to 10-fold higher basal levels of interleukin (IL)-8, IFN-stimulated gene 15 (ISG15), 2',5'-oligoadenylate synthetase (OAS), and Toll-like receptors (TLR)-4, -5, and -7 compared to responders. Non-responders with similar post-treatment follow-ups as responders persistently expressed 6- to 20-fold greater levels of IL-8, ISG15, and OAS after therapy. Higher expression of IFN-α, IFN-γ, and IFN-λ was found in PBMCs of individuals achieving sustained virological response, either before or after therapy. Pre-treatment HCV RNA loads in PBMCs of non-responders were significantly higher (P = 0.016) than those of responders. In conclusion, the data indicate that immune cells of responders and non-responders to IFN/RBV therapy exhibited significantly different virological and host gene expression profiles. Elevated baseline HCV loads and TLR-4, -5, and -7 levels, and persistently high levels of IL-8, ISG15, and OAS were correlated with IFN non-responsiveness. The results warrant further investigations on the utilization of PBMCs for predicting success or failure to IFN-based therapies.

Distribution of HCV genotypes in Poland.

UNLABELLED: Available data on prevalence of HCV genotypes in Poland are insufficient. The aim of the study was the analysis of distribution of HCV genotypes in Poland over the period of recent 10 years regarding the age of patients and the regions of the country. MATERIAL AND METHODS: Analysis of HCV genotypes in Poland was carried out between 2003 and 2012, and included 14 651 patients from 22 centers where patients with chronic viral hepatitis C are diagnosed and treated. Genotypes were analyzed in age groups (< 20 years of age, 20-40 years of age, > 40 years of age) as well as in populations of HBV and HIV co-infections. RESULTS: Genotype (G) 1 infection was demonstrated in 79.4%, G2 -0.1%, G3- 13.8%, G4- 4.9%, G6-0.09% and mixed infections in 1.6%. There was no infection with genotype 5. The highest prevalence of G1 was observed in the Lódzkie voivodship (89.2%) and the Slaskie voivodship (86.7%) while the lowest one in the Warminsko-mazurskie (62.0%) and the Podlaskie voivodships (68.2%). Genotype 3 most commonly occurs in the Warminsko-mazurskie (28.1%), and the Podlaskie voivodships (23.0%) and is least common in the Malopolskie (7.9%) and the Lódzkie voivodships (9.0%). Genotype 4 is more common in the Kujawsko-pomorskie (11.7%) and the Podlaskie voivodships (8.6%) and relatively less common in the Lubelskie (1.1%) and the Lódzkie voivodships (1.8%). Prevalence of G1 infection in 2003-2004 was 72% and increased up to 85.6% in 2011-2012, that was accompanied by decrease of G3 prevalence from 17% to 8% in this period. In HBV co-infected (n = 83), G1 infection was demonstrated in 85.5%, G3 - in 7.2%, G4 -4.8%, and mixed genotypes in 6%. Among HIV co-infected (n = 391), a much lower prevalence of G1 (33.0%) and a high of G3 (40.4%) as well as G4 (24.0%) were observed. CONCLUSIONS: There is a geographic variability of HCV genotypes prevalence in Poland. Increase of HCV G1 infections and decrease of G3 and G4 were observed in the last 10 years. Genotypes G3 and G4 occur more often in HCV/HIV co-infected than in HCV mono-infected patients.

Results of antiviral treatment of patients with chronic hepatitis C: experience of Poznan centre.

INTRODUCTION: Hepatitis C virus (HCV) infection in Poland affects approximately 750 thousand persons. The prevention of cirrhosis and hepatocellular carcinoma, of which approximately 20% of patients with chronic hepatitis C virus are at risk, aims at eradication of the virus by applying antiviral treatment with pegylated interferon alpha with ribavirin. MATERIAL/METHODS: In this paper the results of the standard treatment of chronic hepatitis C in a population of 169 adult patients in whom it was started in the period of 01.01.2007-30.06.2008 are analyzed. Moreover, the influence of various clinical, biochemical and viral factors on achieving therapeutic success in the form of the sustained virological response (SVR) was studied. RESULTS: In the group of 128 patients who received the full course of antiviral treatment, the SVR was achieved by 67.2% of patients (86 persons), whereas regarding all 169 patients who started the therapy, the sustained disappearance of viremia was found in 53.2% of patients (90 persons). Regarding 155 persons in whom the treatment was not interrupted for reasons others than virology, this value was 55.5%. For the sustained disappearance of viremia the following was favorable: genotype 3 virus, age under 40 years, body mass up to 75 kg, correct value of body mass index (BMI), low gamma-glutamyl transpeptidase (GGTP) activity before the treatment, minimum advancement of liver fibrosis in a liver biopsy (S1), complete early biochemical response (cEBR), and moreover, the achievement of negation of viremia after 12 weeks of the treatment in a group of patients infected with genotype 1 (complete early virological response, cEVR). These factors were strongly correlated with each other and that is why an analysis by the method of logistic multiple regression was impossible. Adverse reactions to the treatment and other health problems were the reasons for earlier discontinuation of the standard therapeutic scheme in 14 patients, whereby the lack of an SVR occurred in 10 of them (71.5% which is 5.9% of the studied population).

RNA-HCV viral load in serum, peripheral blood mononuclear cells and liver in children with chronic hepatitis C.

The liver is the major site of hepatitis C virus (HCV) infection and replication. However, HCV may infect and replicate in extrahepatic sites as well. Several investigators have demonstrated that peripheral blood mononuclear cells (PBMCs) are the major extrahepatic milieu of infection and viral replication. The aim of the study was to investigate the correlation between RNA-HCV level in serum. PBMCs and liver in children with chronic viral hepatitis C (CHC). The impact of RNA-HCV level on the sustained virological response (SVR) after therapy was also determined. Study was carried out in the group of 10 children with CHC, age 8 to 17 years. Antiviral therapy was implemented in all patients with pegylated interferon alpha (Peg-lFNalpha) 2a or 2b and ribavirin during 48 weeks. The following tests were performed prior the therapy: basic laboratory parameters, histology of liver biopsy, RNA-HCV viral load in serum, PBMCs and in liver. The behavior of HCV-RNA viral load in serum, PBMCs and liver in children with CHC did not present strict mutual relations. However, the positive correlation between serum and PBMCs viral load (r = 0.47) and negative correlation between PBMCs and liver viral load (r = -0.47) was demonstrated. Although no statistically significant results were found, some trends of relationship in viral load between various body compartments were present. Given the aforementioned results, it is clear that more data are needed, mostly more numerous groups of patients, especially those whose influence of RNA-HCV viral load had a major impact on the antiviral treatment.

Treatment of chronic hepatitis C in children with pegylated interferon α2a and ribavirin--a multi-center study.

Pegylated interferon α and ribavirin in treatment of chronic hepatitis C in children is used rarely. The aim of the study was to find prognostic factors for sustained virological response and to analyze the safety of pegylated interferon α2a and ribavirin in children with chronic hepatitis C. The study covered a group of 44 children, mean age 14 years, with diagnosed chronic hepatitis C. Clinical, biochemical and virological parameters, as well as side effects were evaluated. Combined treatment allowed to obtain sustained virological response in a total of 77.5% of the treated children. Lower viral load and lower fibrosis grade contributed to sustained virological response. The response was not gender-related. The best response is obtained in children whose treatment was started after they attained the age of 10 years. Therapy with pegylated interferon α2a and ribavirin is well tolerated by pediatric patients.