Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Waldemar Halota is active.

Publication


Featured researches published by Waldemar Halota.


Hepatology | 2010

Long‐term entecavir therapy results in the reversal of fibrosis/cirrhosis and continued histological improvement in patients with chronic hepatitis B

Ting-Tsung Chang; Yun Fan Liaw; Shun–Sheng Wu; Eugene R. Schiff; Kwang Hyub Han; Ching-Lung Lai; Rifaat Safadi; Samuel S. Lee; Waldemar Halota; Zachary D. Goodman; Yunchan Chi; Hui Zhang; Robert Hindes; Uchenna H. Iloeje; Suzanne Beebe; Bruce Kreter

One year of treatment with entecavir (0.5 mg daily) in nucleoside‐naive patients with hepatitis B e antigen (HBeAg)‐positive or HBeAg‐negative chronic hepatitis B (CHB) resulted in significantly improved liver histology and virological and biochemical endpoints in comparison with lamivudine. Patients who received at least 3 years of cumulative entecavir therapy in phase 3 studies and a long‐term rollover study and underwent long‐term liver biopsy were evaluated for improvements in histological appearance. Sixty‐nine patients [50 HBeAg‐positive and 19 HBeAg‐negative] receiving entecavir therapy underwent long‐term liver biopsy (median time of biopsy = 6 years, range = 3‐7 years). Histological improvement was analyzed for 57 patients who had adequate baseline biopsy samples, baseline Knodell necroinflammatory scores ≥2, and adequate long‐term biopsy samples. At the time of long‐term biopsy, all patients in the cohort had a hepatitis B virus DNA level <300 copies/mL, and 86% had a normalized alanine aminotransferase level. Histological improvement (≥2‐point decrease in the Knodell necroinflammatory score and no worsening of the Knodell fibrosis score) was observed in 96% of patients, and a ≥1‐point improvement in the Ishak fibrosis score was found in 88% of patients, including all 10 patients with advanced fibrosis or cirrhosis at the phase 3 baseline. Conclusion: The majority of nucleoside‐naive patients with CHB who were treated with entecavir in this long‐term cohort achieved substantial histological improvement and regression of fibrosis or cirrhosis. (HEPATOLOGY 2010)


Hepatology | 2010

Entecavir treatment for up to 5 years in patients with hepatitis B e antigen-positive chronic hepatitis B.

Ting-Tsung Chang; Ching-Lung Lai; Seung Kew Yoon; Samuel S. Lee; Henrique Sérgio Moraes Coelho; Flair José Carrilho; Fred Poordad; Waldemar Halota; Yves Horsmans; Naoky Tsai; Hui Zhang; Daniel J. Tenney; Ricardo Tamez; Uchenna H. Iloeje

Sustained virologic suppression is a primary goal of therapy for chronic hepatitis B (CHB). In study entecavir (ETV)‐022, 48 weeks of entecavir 0.5 mg was superior to lamivudine for virologic suppression for hepatitis B e antigen (HBeAg)‐positive CHB. A total of 183 entecavir‐treated patients from ETV‐022 subsequently enrolled in study ETV‐901. We present the results after up to 5 years (240 weeks) of continuous entecavir therapy. The entecavir long‐term cohort consists of patients who received ≥1 year of entecavir 0.5 mg in ETV‐022 and then entered ETV‐901 with a treatment gap ≤35 days. In ETV‐901 the entecavir dose was 1.0 mg daily. For patients with samples available at Year 5, proportions with hepatitis B virus (HBV) DNA <300 copies/mL, normal alanine aminotransferase (ALT) levels, HBeAg loss, and HBeAg seroconversion were determined. In all, 146 patients met criteria for inclusion in the entecavir long‐term cohort. At Year 5, 94% (88/94) had HBV DNA <300 copies/mL and 80% (78/98) had normal ALT levels. In addition to patients who achieved serologic responses during study ETV‐022, 23% (33/141) achieved HBeAg seroconversion and 1.4% (2/145) lost hepatitis B surface antigen (HBsAg) during study ETV‐901. Through 5 years, entecavir resistance emerged in one patient. The safety profile of entecavir was consistent with previous reports. Conclusion: Extended therapy with entecavir through 5 years maintained or increased rates of HBV DNA suppression and ALT normalization. Additional patients also achieved HBeAg loss and seroconversion. Entecavir provides sustained viral suppression with minimal resistance during long‐term treatment of HBeAg‐positive CHB. (HEPATOLOGY 2010.)


Liver International | 2011

A systematic review of hepatitis C virus epidemiology in Europe, Canada and Israel

Markus Cornberg; Homie Razavi; Alfredo Alberti; Enos Bernasconi; Maria Buti; Curtis Cooper; Olav Dalgard; John F. Dillion; Robert Flisiak; Xavier Forns; Sona Frankova; Adrian Goldis; Ioannis Goulis; Waldemar Halota; B. Hunyady; Martin Lagging; Angela Largen; Michael Makara; Spilios Manolakopoulos; Patrick Marcellin; Rui Tato Marinho; Stanislas Pol; T. Poynard; Massimo Puoti; Olga Sagalova; Scott Sibbel; Krzysztof Simon; Carolyn Wallace; Kendra Young; Cihan Yurdaydin

Background and Aim: Decisions on public health issues are dependent on reliable epidemiological data. A comprehensive review of the literature was used to gather country‐specific data on risk factors, prevalence, number of diagnosed individuals and genotype distribution of the hepatitis C virus (HCV) infection in selected European countries, Canada and Israel.


Free Radical Biology and Medicine | 2002

SUPPLEMENTATION WITH ANTIOXIDANT VITAMINS PREVENTS OXIDATIVE MODIFICATION OF DNA IN LYMPHOCYTES OF HIV-INFECTED PATIENTS

Pawel Jaruga; Barbara Jaruga; Daniel Gackowski; Anita Olczak; Waldemar Halota; Małgorzata Pawłowska; Ryszard Olinski

There is evidence suggesting that patients infected with human immunodeficiency virus (HIV) are under chronic oxidative stress. In the present study, the level of oxidatively modified bases in lymphocyte DNA and some other parameters of oxidative stress were measured in HIV-infected patients (n = 30), as well as in control groups (10 healthy volunteers and 15 HIV-seronegative injected drug users). Additional experiments were conducted using lymphocyte DNA samples from asymptomatic seropositive, HIV-infected patients who were supplemented with antioxidant vitamins A, C, and E or received placebo. Significant increases in the amount of the modified DNA bases were observed in HIV-infected patients when compared with the control group. The concentration of thiobarbituric acid reactive substances (TBARS) was higher and activities of antioxidant enzymes (superoxide dismutase and catalase) were lower in the group of HIV-infected patients in comparison to the control group. Vitamin supplementation resulted in the significant decrease in the levels of all modified DNA bases when compared to the patients who received placebo. The reduction of TBARS and the restoration of the activity of the enzymes were also observed. Our data suggest that people infected with HIV can benefit from treatment with antioxidant vitamins.


European Journal of Gastroenterology & Hepatology | 2011

Prevalence and risk factors of HCV infection in Poland.

Robert Flisiak; Waldemar Halota; Andrzej Horban; Jacek Juszczyk; Małgorzata Pawłowska; Krzysztof Simon

Background According to small studies carried out in preselected populations, the estimated prevalence of anti-hepatitis C virus (HCV) antibodies in Poland ranges from 0.6 to 2.1%. Aims The aim of this study was to evaluate the prevalence of anti-HCV and HCV RNA among patients and healthcare workers. Methods Anti-HCV antibodies were measured (Elecsys, Roche) in serum samples from 26 057 adults, consecutive patients or healthcare workers, from hospitals and out patient clinics not involved in the management of liver diseases. The majority of them (18 233) consented to fill out an anonymous questionnaire related to possible risk factors for HCV infection. Anti-HCV-positive samples were assessed for HCV RNA (Cobas Amplicor, Roche). A multivariate logistic regression model and the &khgr;2 test or the Fishers exact test were applied. Results Anti-HCV antibodies were detected in 1.9% of individuals, and 31% of them demonstrated HCV RNA, which varied from 26% in hospitals to 66% in specialistic out-patient clinics. Prevalence of anti-HCV was significantly lower in healthcare workers (1.42%) than in patients (1.92%). Significant independent risk factors for anti-HCV positivity were as follows: male sex, more than three hospitalizations in a lifetime, blood transfusions before 1992, and intravenous drug use. The only significant risk factor for HCV RNA was intravenous drug use. An analysis carried out for multispecialistic hospitals demonstrated significantly lower prevalence of HCV RNA positivity in healthcare workers. Conclusion Prevalence of anti-HCV in the Polish population studied was up to 1.9%, but active infection could be diagnosed in only 31% of them. Intravenous drug use, blood transfusions before 1992, multiple hospitalizations, and male sex increase the risk of HCV infection.


Journal of Hepatology | 2016

Efficacy and safety of elbasvir/grazoprevir and sofosbuvir/pegylated interferon/ribavirin: A phase III randomized controlled trial

Jan Sperl; Gábor Horváth; Waldemar Halota; Juan Arenas Ruiz-Tapiador; Anca Streinu-Cercel; Ligita Jancoriene; Klára Werling; Hege Kileng; Seyfettin Köklü; Jan Gerstoft; Petr Urbánek; Robert Flisiak; Rafael Alexander Leiva; Edita Kazenaite; Renate Prinzing; Sushma Patel; J. Qiu; Ernest Asante-Appiah; Janice Wahl; Bach-Yen Nguyen; Eliav Barr; H.L. Platt

BACKGROUND & AIMS Direct-acting antiviral agents have improved treatment outcomes for patients with hepatitis C virus (HCV) infection; however, head-to-head comparisons are limited. The C-EDGE Head-2-Head Study compared the safety and efficacy of elbasvir/grazoprevir (EBR/GZR) with sofosbuvir plus pegylated interferon/ribavirin (SOF/PR) in patients with HCV infection. METHODS This was a randomized, open-label, phase III trial. Two hundred fifty-seven patients with HCV genotype (GT)1 or 4 infection and baseline viral load >10,000IU/ml were randomized to receive 12weeks of EBR/GZR 50mg/100mg once daily (n=129) or sofosbuvir (400mg once daily) plus PR (n=128). Primary efficacy objective was sustained virologic response 12weeks after the end of therapy (SVR12, HCV RNA <15IU/ml). The primary safety objective was the proportion of patients experiencing a tier 1 safety event. RESULTS The majority of patients were non-cirrhotic (83.1%), treatment-naïve (74.9%) and had HCV GT1b infection (82.0%). SVR12 rates were 99.2% (128/129) and 90.5% (114/126) in the EBR/GZR and SOF/PR groups, respectively. The estimated adjusted difference in SVR12 was 8.8% (95% confidence interval [CI], 3.6-15.3%). Because the lower bound of the 1-sided 1-sample exact test was greater than -10% and greater than zero, both non-inferiority and superiority of EBR/GZR vs. SOF/PR were established. The frequency of tier 1 safety events was lower among patients receiving EBR/GZR than SOF/PR (0.8% vs. 27.8%, between group difference, 27.0% [95% CI, -35.5% to -19.6%; p<0.001]). CONCLUSIONS EBR/GZR has a superior efficacy and safety profile in patients with HCV GT1 or 4 infection compared with SOF/PR. LAY SUMMARY The combination of elbasvir/grazoprevir for 12weeks was highly effective in treating patients with chronic hepatitis C, genotypes 1 or 4 infection. This regimen was more effective than sofosbuvir/pegylated interferon/ribavirin for 12weeks, and was notably superior in patients regarded as difficult to treat, including those with previous treatment failure, cirrhosis, or a high baseline viral load. The combination of elbasvir/grazoprevir also demonstrated a superior safety and tolerability profile based on fewer serious adverse events, no serious drug-related adverse events, and no treatment discontinuations. CLINICAL TRIAL REGISTRATION Clinical trials.gov Identifier: NCT02358044.


Hepatitis Monthly | 2013

Association of IL28B Polymorphisms With the Response to Peginterferon Plus Ribavirin Combined Therapy in Polish Patients Infected With HCV Genotype 1 and 4

Krzysztof Domagalski; Małgorzata Pawłowska; Andrzej Tretyn; Waldemar Halota; Malgorzata Tyczyno; Dorota Kozielewicz; Dorota Dybowska

Background Three single nucleotide polymorphisms (SNPs) near interleukin-28B (IL-28B) gene were shown to be highly associated with treatment response (SVR) in patients with chronic hepatitis C virus (HCV) infection. There is limited data about the role of single and combined IL-28B polymorphisms in HCV-infected Polish population. Objectives This studys aim was to determine predictability of three IL-28B gene polymorphisms and other known prognostic factors on the treatment response in HCV genotype 1 and 4 infected Polish patients. The effect of IL-28B polymorphisms on therapy was also compared with other known prognostic factors. Patients and Methods We genotyped IL-28B polymorphisms (rs12979860, rs12980275 and rs8099917) by polymerase chain reaction-based restriction fragment length polymorphism assay in a group of 293 patients from which a selected cohort of 174 treatment-naiev patients underwent treatment. Results We showed that rs12979860 CC [odds ratio (OR) = 4.6, P < 0.001], rs12980275 AA (OR = 2.9, P = 0.002) and rs8099917 TT (OR = 2.2, P = 0.016) genotypes were associated with successful treatment compared to the rs12979860 CT-TT, rs12980275 AG-GG and rs8099917 TG-GG, respectively. Patients bearing of IL-28B profile including the three favourable genotypes do not have much chance of a recovery (OR = 3.4, P = 0.002). Except for IL-28B polymorphisms, there was no association of SVR with any other pretreatment clinical data in analyzed group. The correlation of SNPs with other host and viral factors revealed association of favorable genotypes of IL-28B markers with high levels of alanine aminotransferase and baseline HCV viral load. Conclusions IL-28B polymorphisms were the strongest pretreatment predictors of response to pegylated interferon and ribavirin in Polish patients chronically infected with HCV genotype 1 and 4. This study confirm the strongest impact of IL-28B rs12979860 on SVR, nevertheless rs12980275 AA seems to be more important than rs8099917 TT in predicting positive treatment response.


World Journal of Gastroenterology | 2015

What's new in hepatitis C virus infections in children?

Małgorzata Pawłowska; Krzysztof Domagalski; Anna Pniewska; Beata Smok; Waldemar Halota; Andrzej Tretyn

The number of hepatitis C virus (HCV) infection cases is relatively low in children. This low number may be connected with the lack of screening tests and the asymptomatic course of infection. Currently, mother-to-infant transmission is the most common cause of HCV infection amongst children in developed countries. It is important to introduce routine screening tests for HCV in pregnant women. The risk of vertical transmission of HCV is estimated at approximately 5% (3%-10%). Currently, we do not have HCV transmission prevention methods. Some factors could potentially be eliminated by elective caesarean section. Currently, the method of prevention of perinatal HCV infection is the early identification and effective treatment of infections in young women in the preconception period. We describe genetic tests (IL-28B single nucleotide polymorphisms) to identify children with an increased chance of spontaneous clearance or sustained virologic response achievement and vitamin D level as a potential predictor of treatment response in children. It is also important to develop non-invasive tests that can predict liver fibrosis. The existence of differences in the mechanisms leading to liver injury between children and adults creates new perspectives of action to reduce liver disease progression in children in the early years of life.


Hepatitis Monthly | 2012

HEMATOLOGICAL ADVERSE EVENTS AND SUSTAINED VIRAL RESPONSE IN CHILDREN UNDERGOING THERAPY FOR CHRONIC HEPATITIS C INFECTION

Małgorzata Pawłowska; Malgorzata Pilarczyk; Anna Foksinska; Ewa Smukalska; Waldemar Halota

Background Treatment of hepatitis C virus (HCV) infection with interferon (IFN) and ribavirin (RBV) is associated with adverse events, which may affect the patients adherence to the treatment regimen and the treatment efficacy. Objectives The aim of this study was to assess the sustained viral response (SVR) and interdependence between the haematological characteristics (leukocyte count, platelet count, and haemoglobin levels) in patients with chronic hepatitis C (CHC) infection during treatment with IFN and RBV. Patients and Methods We conducted a retrospective cohort study of 170 children with CHC infection who completed treatment with IFN-α and RBV. The children were divided into 2 groups: the first group (group I, n = 119) underwent a 48-week course of treatment with recombinant IFN α-2b (Intron A) at a dosage of 3 MU 3 times a week subcutaneously and RBV at a dosage of 15 mg/kg per day orally, and the second group (group II, n = 51) was administered pegylated IFN (peg-IFN)-α-2b (PegIntron) at a dosage of 1.5 μg/kg per week subcutaneously and RBV at a dosage of 15 mg/kg per day orally for 48 weeks. The dose of IFN was not adjusted but that of ribavirin was in 2 children from group II. Hematological growth factors and erythropoietin were not used. SVR was defined as undetectable serum HCV RNA 24 weeks after the end of treatment (study week 72). Serum HCV RNA was determined by performing polymerase chain reaction, and the HCV genotypes and hematological parameters were evaluated. Serum HCV RNA levels were analysed by descriptive statistics. Means and standard deviations were calculated for values collected at the baseline, on the 12th and 48th weeks during treatment, and after 24 weeks of untreated follow-up (study week 72). Results Eighty-six (50%) of the 170 patients who underwent treatment achieved SVR: 62 (51%) out of 119 children from group I and 24 (47%) out of 51 from group II. The mean serum hemoglobin levels and leukocyte and platelet counts at week 12 were significantly lower than the baseline values in both responders and non-responders from both the groups (P < 0.05). In the responders in group I, the mean levels of serum hemoglobin after 24 weeks of treatment and at the end of therapy were significantly lower than the mean levels at baseline. In the group treated with peg-IFN-α-2b and RBV (group II), the mean serum hemoglobin levels at week 12 was lower in the responders than in the non-responders (P < 0.05). The decrease in the hemoglobin levels was associated with viral response. In both the responders and non-responders from both the groups, leukocyte counts decreased during treatment, and after 12 weeks, they were more significantly lower than the baseline value. The decrease was more marked in children treated with peg-IFN-α-2b + RBV (P < 0.05). After 12 weeks of treatment, the platelet count was low in children from group II who had achieved SVR. Conclusions A mild decrease in hemoglobin levels and leukocyte and platelet counts during treatment with IFN and RBV in children with CHC infection may be factors responsible for SVR induction.


European Journal of Gastroenterology & Hepatology | 2015

Forecasting the disease burden of chronic hepatitis C virus in Poland.

Robert Flisiak; Waldemar Halota; Krzysztof Tomasiewicz; Kaja Kostrzewska; Homie Razavi; Erin Gower

Background and aims Chronic hepatitis C virus infection is prevalent among 200 000 individuals in Poland; however, few are aware of their condition (30 000 diagnosed) and even fewer are treated (2490 in 2014). This analysis projected future disease burden and developed two treatment scenarios to control or eliminate hepatitis C virus-related disease in Poland. Methods Using a modeling approach, the infected population and future disease progression were quantified. Baseline variables included viremic prevalence, age and sex, diagnosis rate, treatment rate, disease progression, and sustained virologic response rates. Data were collected from the literature and through expert interviews. Results The number of prevalent hepatitis C virus infections is projected to decrease (5%) by 2030. However, the numbers of individuals with compensated and decompensated cirrhosis, and hepatocellular carcinoma are estimated to increase by 40, 55, and 60%, respectively. By increasing sustained virologic response rates to 95% from 2015 onward, and the number of treated cases (from 2490 to 5000), the number of individuals with cirrhosis, decompensated cirrhosis, and hepatocellular carcinoma is projected to remain constant until 2030. A strategy to eliminate chronic hepatitis C virus infection was also considered. To reduce total infections by 90% and mortality by 80%, treatment was increased to 15 000 patients annually. This scenario required the diagnosis of 15 000 new cases (compared with 3000 today). Conclusion A marked reduction in hepatitis C virus-related disease burden is possible, with increased diagnosis and treatment. The results could inform the development of effective disease management in Poland.

Collaboration


Dive into the Waldemar Halota's collaboration.

Top Co-Authors

Avatar

Małgorzata Pawłowska

Nicolaus Copernicus University in Toruń

View shared research outputs
Top Co-Authors

Avatar

Robert Flisiak

Medical University of Białystok

View shared research outputs
Top Co-Authors

Avatar

Krzysztof Simon

Wrocław Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Dorota Dybowska

Nicolaus Copernicus University in Toruń

View shared research outputs
Top Co-Authors

Avatar

Dorota Kozielewicz

Nicolaus Copernicus University in Toruń

View shared research outputs
Top Co-Authors

Avatar

Andrzej Horban

Medical University of Warsaw

View shared research outputs
Top Co-Authors

Avatar

Andrzej Tretyn

Nicolaus Copernicus University in Toruń

View shared research outputs
Top Co-Authors

Avatar

Jerzy Jaroszewicz

Medical University of Białystok

View shared research outputs
Top Co-Authors

Avatar

Krzysztof Domagalski

Nicolaus Copernicus University in Toruń

View shared research outputs
Researchain Logo
Decentralizing Knowledge