Mpox virus detection in the wastewater and the number of hospitalized patients in the Poznan metropolitan area, Poland.

OBJECTIVES: Wastewater-based epidemiology can determine the scale of a mpox epidemic and thus is a promising additional tool that can complete data gathered by the clinical monitoring approach and predict more accurately the development and progress of the current mpox outbreak. METHODS: We collected daily average samples from two wastewater treatment plants (WTPs): Central and Left-Bank, in Poznan, Poland from July to December 2022. The mpox DNA was detected using real-time polymerase chain reaction and compared with the number of hospitalizations. RESULTS: We detected the mpox DNA in the Central WTP in weeks 29, 43, and 47 and the Left-Bank WTP mostly from mid-September till the end of October. A total of 22 patients with mpox were reported by the public health authority from July to December 2022, with the highest number of hospitalized individuals from mid-July to mid-August. The mpox virus detection does not correlate with the number of hospitalizations in Poznan, Poland. CONCLUSION: Our results suggest that the scale of the mpox epidemic is underestimated, and many mpox virus-infected individuals are not identified by the public health authority.

Self-reactive IgE and anti-IgE therapy in autoimmune diseases.

Growing evidence indicates the pathogenic role of autoreactive IgE in autoimmune diseases. Incidence of autoimmune and allergic diseases in the industrialized countries is consistently icreasing, thus leading to concerted efforts to comprehend the regulation of IgE-mediated mechanisms. The first reports of a presence of IgE autoantibodies in patients with autoimmune diseases have been published a long time ago, and it is now recognized that self-reactive IgE can mediate inflammatory response in bullous pemhigoid, systemic lupus erythematosus, chronic urticaria, and atopic dermatitis. The advances in understanding the pathomechanisms of these disorders brought to a successful use of anti-IgE strategies in their management. The present review discusses the current state of knowledge on the IgE-mediated autoimmunity and anti-IgE treatment, and pave the way for further exploration of the subject.

Treg cells in the course of chronic hepatitis C virus infection partially normalize in longitudinal observation after successful DAA treatment regardless of hepatic fibrosis stage.

AIM OF THE STUDY: Elevated circulating CD4+ CD25+ Foxp3+ regulatory T cells in patients with chronic hepatitis C (CHC) play an unspecified role in liver fibrosis development. This study aimed to determine whether Treg cells diminish after successful treatment with directacting antivirals (DAA) in patients at different liver fibrosis stages. MATERIAL AND METHODS: We examined 44 patients with CHC (including 29 with liver cirrhosis) seven days before DAA treatment (T0), six months later (T1) and then 22 of them were examined one year (T2) after the first dose. Subsequently, these were compared with 28 volunteers without hepatitis C virus (HCV) (15 with excessive alcohol intake). We assessed the degree of liver fibrosis with FibroScan, aspartate transaminase (AST) to platelet ratio index (APRI), FibroIndex, the Forns index and Fib-4. Circulating Treg cells were measured using flow cytometry. RESULTS: All patients achieved a sustained virological response (SVR). After the treatment, all liver fibrosis indicators decreased significantly. The number of circulating Tregs was lower in healthy controls than in patients with CHC (0.0066 × 103 cells/µl and 0.0084 × 103 cells/µl, respectively, p = 0.048). After the treatment we observed an insignificant change to 0.0047 × 103 cells/µl for T1 (p > 0.05) and a significant fall to 0.0041 × 103 cells/µl for T2 (p = 0.03). There was no correlation between the degree of hepatic fibrosis and number of Tregs or post-treatment dynamics. CONCLUSIONS: Our study shows that Treg cells normalize gradually over a prolonged period of time after a successful DAA treatment. Their number and dynamics remain independent of liver fibrosis degree. The correlation of this revelation with metabolic disorders, increased susceptibility to infections or persistent risk of HCC remains unclear.

Changes in Inflammatory Markers after Administration of Tocilizumab in COVID-19: A Single-Center Retrospective Study.

The COVID-19 pandemic requires the development of effective methods for the treatment of severe cases. We aimed to describe clinical outcomes and changes in inflammatory markers in Polish patients treated with tocilizumab. The medical charts of SARS-CoV-2-positive patients treated in the Department of Infectious Diseases between 4 March and 2 September 2020 were retrospectively analyzed. The patients who received tocilizumab according to the Polish Association of Epidemiologists and Infectiologists guidelines were selected for the study. We identified 29 individuals who received tocilizumab, out of whom 11 (37.9%) died. The individuals who died had significantly higher maximal interleukin-6 (IL-6) and lactate dehydrogenase (LDH) serum levels than survivors. After administration of tocilizumab, further increase in LDH and IL-6 was a prognostic factor for unfavorable outcomes. Among inflammatory markers, 7-day mean of IL-6 serum concentration was the best predictor of death (cut-off: ≥417 pg/mL; area under ROC curve = 0.81 [95% Confidence Interval: 0.63-0.98]). The serum concentrations of inflammatory markers before administration of tocilizumab did not predict the outcome, whereas IL-6 and LDH measurements after administration of tocilizumab seemed to be of predictive value.

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.

Pattern Recognition Receptors: Significance of Expression in the Liver.

Pattern recognition receptors (PRRs) are a pivotal part of the immune system. They are distributed in almost every site of higher organisms, able to recognize foreign pathogens or unwanted remnants of metabolism and mount innate immune response. Moreover, PRRs create bridging signaling to initiate adaptive immunity. The liver being the largest organ of the body, exposed to myriads of foreign substances often being immunogenic, is well equipped with PRRs. They act as sentinels of the organ, both in health and disease. In viral hepatitis C at least two of them, RIG-1 and TLR3 sense HCV, induce protective interferon production and create proinflammatory status. The hepatitis B virus is apparently invisible to PRRs, which has recently been denied. Besides, they are active in the course of infection. In liver injury and hepatic fibrogenesis Toll-like receptors (TLRs), predominantly TLR4, TLR3 and TLR9 are associated with gut microflora-related products and DNA from dying hepatocytes, lead to the activation of hepatic stellate cells. The latter initiate production of fibrillar collagens, the main agents forming hepatic fibrosis. Tumor cells of primary liver cancer also express PRRs, mainly TLRs. In concert with non-resolving liver inflammation, they are considered pivotal factors leading to carcinogenesis.

Impact of chronic HCV treatment on quality of life of patients with metabolic disorders in context of immunological disturbances.

Chronic viral hepatitis C (CHC) and its complications have a negative effect on patient's quality of life. We evaluated the impact of a successful interferon-free treatment on the quality of life of patients with obesity and metabolic disorders in the context of immunological disturbances. Twenty overweight or obese (BMI > 25) patients with CHC were tested before the therapy and after a successful treatment regimen. After the therapy, patient's emotional well-being improved (p = 0.02), while physical well-being remained unchanged. There was a decrease of patient's liver fibrosis and an increase of steatosis along with body mass. Among HCV-infected individuals, the expression of toll-like receptor 3 (TLR3) on lymphocytes was higher than in the control group (p = 0.03), but it decreased (p = 0.001) after the treatment. There was also a decrease of the intensity of immunofluorescence of FoxP3+ after the treatment (p = 0.04). Our study showed an improvement in mental aspects of patient's quality of life after the treatment. Unfortunately, probably due to rapid immunological changes, patient's BMI, serum cholesterol levels and hepatic steatosis have a tendency to increase and may lead to cardiovascular and other complications, like hepatocellular carcinoma.

Correction to: Significance and Role of Pattern Recognition Receptors in Malignancy.

The authors would like to correct the following error.

Significance and Role of Pattern Recognition Receptors in Malignancy.

Pattern recognition receptors (PRRs) are members of innate immunity, playing pivotal role in several immunological reactions. They are known to act as a bridge between innate and adaptive immunity. They are expressed on several normal cell types but have been shown with increasing frequency on/in tumor cells. Significance of this phenomenon is largely unknown, but it has been shown by several authors that they, predominantly Toll-like receptors (TLRs), act in the interest of tumor, by promotion of its growth and spreading. Preparation of artificial of TLRs ligands (agonists) paved the way to use them as a therapeutic agents for cancer, so far in a limited scale. Agonists may be combined with conventional anti-cancer modalities with apparently promising results. PRRs recognizing nucleic acids such as RIG-1 like receptors (sensing RNA) and STING (sensing DNA) constitute a novel promising approach for cancer immunotherapy.

The prevalence of mixed genotype infections in Polish patients with hepatitis C.

OBJECTIVES: Hepatitis C virus (HCV) genotype has been described as an independent predictor of the response to therapy. A mixed infection with two types of HCV is probably an uncommon event. The aim of this study was to determine the occurrence of mixed infection with two different HCV genotypes in adult patients with chronic hepatitis C eligible for treatment. METHODS: Plasma samples and clinical and demographic data were collected from 1159 patients with hepatitis C. The INNO-LiPA HCV assay was used to identify the HCV genotypes. RESULTS: The dominant genotype was genotype 1, which was found to be responsible for 83.9% of infections, with subtype 1b being the most common. A mixed genotype infection was detected in 26 patients (2.2%). The most common mixed genotype was 1a+1b detected in 17/26 patients (65%). Antiviral therapy led to complete elimination of both genotypes in 50% of patients with 1b+3a infection and in 33% of patients with 1b+4a infection. CONCLUSIONS: The results obtained showed that infection with mixed HCV genotypes in Polish patients with hepatitis C is uncommon. The selective elimination of genotypes 3a and 4a after therapy confirms the greater resistance to treatment of genotype 1b. In the context of new anti-HCV drug development, further investigations are needed to determine the clinical importance of mixed HCV infection.

Genetic (KIR, HLA-C) and Some Clinical Parameters Influencing the Level of Liver Enzymes and Early Virologic Response in Patients with Chronic Hepatitis C.

Natural killer cells play an important role as effectors of innate immunity and regulators of adaptive immunity. They are important elements of the innate response to viral infections, which they detect using human leukocyte antigen (HLA) class I-binding receptors. Most polymorphic of these are killer cell immunoglobulin-like receptors (KIRs) which exist as two basic isotypes, activating or inhibitory receptors and are encoded by genes distributed differently in unrelated individuals. We searched for links between selected clinical data (including HCV viremia, liver enzymes level and liver histology parameters) and the presence of genes encoding these receptors and their ligands in hepatitis C virus-infected individuals subjected to pegylated interferon-α and ribavirin therapy. Genomic DNA samples from two hundred and ninety-two chronically infected patients were typed by polymerase chain reaction for the presence or absence of genes for KIRs and their ligands, class I HLA molecules, and clinical data of the patients were collected. Our results suggest an importance of clinical parameters and the contribution of KIR and HLA genes to the course of hepatitis C virus infection and the response to therapy. The study revealed that levels of liver enzymes before therapy were about 30% higher in patients who possessed a variant KIR2DS4 gene with 22-base pair deletion. Decrease of ALT activity after treatment was higher in HLA-C C2-positive than negative individuals. Beside it, patients demonstrated early virologic response to the therapy if the time lag before treatment was short, particularly in women.

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.

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.

Contribution of genes for killer cell immunoglobulin-like receptors (KIR) to the susceptibility to chronic hepatitis C virus infection and to viremia.

BACKGROUND: Natural killer (NK) cells are an important element of innate immunity against viruses, although their numbers decrease in the liver during chronic HCV infection. NK cells express a large panel of inhibitory and activating receptors. The most polymorphic of these are killer cell immunoglobulin-like receptors (KIRs) which are encoded by multiple genes that may be present or absent in given individuals depending on their genotype. This variability results in differential susceptibility to viral infections and diseases, including HCV infection and its consequences. AIMS AND METHODS: The aim of this study was to test whether chronical infection with HCV and the viremia levels are associated with any KIR gene in the Polish population. We typed 301 chronically HCV-infected patients and 425 non-infected healthy individuals for the presence or absence of KIR genes and their ligands, HLA-C C1 and C2 groups as well as HLA-B and HLA-A Bw4-positive alleles. RESULTS: We found that males, but not females, possessing KIR2DS2 and KIR2DL2 genes had a 1.7 higher probability to become chronically HCV-infected than males negative for these genes (p=0.0213). In accord with this, centromeric B region, containing KIR2DS2 and KIR2DL2 genes, was also associated with chronic HCV infection in males. In addition, patients of both genders possessing KIR2DS3 but not KIR2DS5 gene exhibited, on average, 2.6 lower level of viremia than HCV-infected individuals with other genotypes (p=0.00282). This was evident in those infected at a young age. KIR2DS3-positive patients also had lower mean levels of bilirubin than KIR2DS3-negative ones (p=0.02862). CONCLUSION: Our results suggest a contribution of the KIR2DS2 and KIR2DL2 genes (cenB haplotype) to the susceptibility to chronic HCV infection, and an association of the KIR2DS3 gene in the absence of KIR2DS5 with low viremia levels.

Viral Hepatitis A in 108 Adult Patients During an Eight-Year Observation at a Single Center in Poland.

BACKGROUND: Hepatitis A is related to significant morbidity and occasional mortality. Based on data from the Polish National Institute of Hygiene, from 2000 to 2013 a mean of 213 hepatitis A cases were reported yearly. OBJECTIVES: The aim of the study was to assess selected data in adults hospitalized for symptomatic hepatitis A during an eight-year period in a single center in the Wielkopolska Region of Poland. MATERIAL AND METHODS: All the hepatitis A patients hospitalized in the center from 2005 to 2013 were analyzed retrospectively. Data were extracted from the medical records of these individuals. The disease was confirmed by anti-HAV IgM testing. RESULTS: In total, 108 patients (71 men and 37 women), aged 18-65 years, were identified. All but 1 patient recovered (99.1%) and in 6 cases (5.6%) a relapse occurred. Risk factors for hepatitis A were identified in 56 patients (52%), with travel abroad being the most common one (32 patients); 19 cases were secondary and 5 patients were men who have sex with men. One hepatitis A outbreak was noted in the region during the study period. Acalculous cholecystitis was found in 33.3% of the patients who underwent abdominal ultrasound. This tended to be more common among older individuals (47.8% in patients over 40 vs. 22.6% in patients aged 18-40, p=0.0521). Patients with this finding had significantly higher mean peak ALT in comparison to those with no gallbladder abnormalities. CONCLUSIONS: Although hepatitis A in adults is typically a benign, self-limited disease, it can occasionally have a fatal course. In a significant proportion of patients with an evident risk factor for hepatitis A, the possibility of active prophylaxis was not used. Hepatitis A should be regarded as a sexually transmitted infection. Acalculous cholecystitis is a frequent finding among adults with symptomatic hepatitis A.

Detection and significance of cytotoxic cell subsets in biopsies of HCV-infected human livers.

Chronic viral hepatitis C still remains the clinical challenge. Attempts of the immune system to cope with this infection are unsatisfactory. There is a conviction that the main site of interaction between virus (Hepatitis C virus, HCV) and immune system is in situ, i.e., in liver. Natural killer (NK) cells appeared relevant in the acute hepatitis. Less is known about the immune response in the chronic HCV infection. The aim of this study was to evaluate the prevalence of various cytotoxic cell subsets in chronic HCV+ liver tissue and to seek links between them and laboratory data of patients. Sections from paraffin blocks of liver biopsy tissues of HCV+ untreated patients were subjected to the reaction with antibodies vs. cytotoxic cell subsets and immunohistochemistry. Positive cells were searched in cellular infiltrates in portal areas and in liver parenchyma. They were classified on the "Yes" or "No" basis. Majority of liver biopsies exhibited cellular infiltrates in portal spaces and as single cells in liver parenchyma. Infiltrates consisted of CD8+ T cells, CD56+ NK ones, including CD158i+ and CD158b+. The latter were rarely seen. There were also granzyme B+ cells. The most abundant were NKG2D+ cells, much more common than NK CD56+ ones. It implied that NKG2D was also expressed on T cells. Prevalence of NKG2D+ cells correlated with high activity of liver enzymes such as alanine aminotransferase, aspartate aminotransferase and a greater histological severity of liver injury. NKG2D+ cells form the bulk of cells infiltrating HCV-infected human liver. Correlation of NKG2D+ cells with some laboratory parameters of patients suggests their role in hepatitis C pathogenesis.

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.

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.

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).

Evolution of hepatitis C virus hypervariable region 1 in chronically infected children.

Hepatitis C virus (HCV) quasispecies diversification plays an essential role in the establishment of chronic infections. Our earlier analysis of HCV population structure in children subjected to interferon-ribavirin treatment demonstrated that viral quasispecies is homogenous in patients who failed to respond to the therapy and heterogeneous in sustained responders. We also showed that certain variants of HCV hypervariable region 1 (HVR1) are conserved in non-responders. To better elucidate the pathways of HCV evolution, here we examined the changes of HVR1 in viral populations isolated from sera of eight treatment-naive pediatric patients. We found that HCV evolution in untreated chronically infected children occurs according to two pathways and results in the formation of either genetically homogenous or variable quasispecies. Variable populations are prone to quasispecies shifts. In contrast, homogenous populations are composed of closely related variants that undergo only minor changes. In addition, we observed that a phenomenon of inter-quasispecies conservation of HVR1 is associated with some of the homogenous HCV populations. The collected data suggest that there exist HVR1 variants with superior fitness, capable of persisting in different hosts.