[Frequency and characteristics of hepatitis B infection in children with malignant diseases]

INTRODUCTION

Hepatitis B, a complication of blood transfusion or other means of transmission, occurs with variable frequency in children with malignant diseases.

OBJECTIVE

The objective of this study was to determine the frequency of hepatitis B virus infection in children with malignant diseases, to investigate the clinical course of the illness, and to analyse the influence of hepatitis on cytotoxic treatment.

METHOD

The study included children diagnosed and treated for malignant diseases at the University Children's Hospital in Belgrade from 1997 to 2003. HBs Ag was analysed in all patients who had elevated transaminases of twice normal value, in children who had icterus, and in one group of patients treated routinely after 2001 before, during, and after therapy. RESULTS A total of 137 male and 107 female children who had malignancies were treated. From 113 children who were evaluated for the presence of HBs Ag at the beginning of treatment, 2 (1.7%) were HBsAg+. In this group of patients HBsAg was tested in 58 (51%) children during and after chemotherapy, and HBsAg was discovered in 17 (29%) of them. Of 123 children, in whom HBsAg was not tested at the beginning of their illness, 36 (55%) out of 66 (51%) tested patients were HBsAg+. No statistical difference between those two groups of patients was ascertained (chi2 = 3.27, p > 0.05). In summary, the presence of HBsAg was discovered in 53 patients, 22% out of 244 patients and 43% of tested patients. Nine patients had the icteric form of illness, with one case proving fatal due to fulminating hepatitis.

CONCLUSION

Taking into consideration the uncertain long-term prognoses of these patients, follow-up and treatment is essential.

Pathogenesis and treatment opportunities for biliary atresia

Biliary atresia is the single most common cause of chronic cholestasis in children and is the leading indication for liver transplantation worldwide. It results from an inflammatory and fibrosing obstruction of the extrahepatic bile ducts in the first few months of life. Early diagnosis and timely surgical portoenterostomy are necessary for improved biliary drainage, but the liver disease progresses to end-stage biliary cirrhosis in most patients. Although the pathogenesis of disease is largely unknown, recent patient- and animal-based experiments indicate interactions between infectious agents and inflammatory circuits may be important pathogenic mechanisms of disease.

Post-portoenterostomy triangular cord sign prognostic value in biliary atresia: a prospective study

The triangular cord sign (TC sign) is a sensitive and specific tool in prompt diagnosis of extrahepatic biliary atresia. The objective of this study is to evaluate post-operative TC sign presence in outcome prediction of infants with biliary atresia after Kasai hepato-portoenterostomy 27 infants and children with biliary atresia underwent 122 ultrasound examinations using both 5 MHz and 7 MHz convex linear transducers in 33 months follow up. For all infants TC sign identification was included pre-operatively, ultrasound was done 2 weeks post-operatively then bimonthly for 3 months, monthly for 2 months and every 3 months thereafter. 14 (53.8%) had post-operative TC sign. Once post-operatively positive, it remained positive throughout the study. It did not reappear in an initially post-operatively TC sign negative infant. Those having post-operative TC sign had statistically worse outcomes (0 became anicteric, 2 improved, 7 had progressive disease and 6 died) than those with a negative TC sign (p = 0.04) (3 became anicteric, 5 improved, 2 progressed and 1 died). Presence of TC sign post-operatively correlated with measure of removal of all fibrous cone at porta-hepatis during portoenterostomy (p = 0.026). Post-portoenterostomy TC sign is associated with more morbidity and mortality; and reflects inadequate surgical technique.

Hepatitis B virus and hepatitis C virus infections in children

PURPOSE OF REVIEW

To analyse the most relevant recent information on efficacy, duration and coverage of anti-hepatitis B virus vaccination; correlates of mother-to-child hepatitis C virus transmission; the natural history and outcomes of hepatitis B and C virus infections in children; the efficacy and safety of specific therapies.

RECENT FINDINGS

Insufficient hepatitis B virus vaccine coverage and incomplete or delayed vaccine cycles need improvement in many countries. Hepatitis B virus mutants may explain some fulminant hepatitis in perinatally infected infants and vaccine failures. No interventions to prevent vertical hepatitis C virus transmission have been identified. Spontaneous clearance of hepatitis B is lower in children than in adults, while the rates appear to be similar for hepatitis C. The disease progression is slower for both infections in childhood. Several studies support the efficacy and safety of interferons and lamivudine in chronic hepatitis B or of interferons and ribavirin in chronic hepatitis C in children, but the optimal therapy remains unclear.

SUMMARY

There are doubts as to the long-term persistence of anti-hepatitis B immunization in low-endemicity areas. Routine hepatitis C virus testing in pregnancy is not recommended as there are no available prophylactic measures. Although hepatitis B and C virus infections are usually asymptomatic or with mild manifestations in childhood, concerns around their long-term clinical impact suggest the need for early treatment. Children should preferably be treated in the context of targeted trials for a better understanding of the efficacy and tolerance of drugs currently used in adults.

Randomized trial of a single, double and triple dose of 10 mg/kg of a human formulation of triclabendazole in patients with fascioliasis

1. A study performed > 10 years ago and case reports published recently suggest that triclabendazole is effective for the treatment of patients with fascioliasis. 2. To confirm the efficacy of a human formulation of triclabendazole, we enrolled 165 patients into the present study and divided the subjects into two groups: (i) those who had fascioliasis, as evidenced by the presence of ova in their stools; and (ii) patients with clinical and laboratory data suggesting fascioliasis. 3. Patients were randomly allocated to receive 10 mg/kg, p.o., triclabendazole for 1, 2 or 3 days (single-, double- and triple-dose groups, respectively). Medical history and physical and laboratory examinations were performed at baseline and at 7, 14, 30 and 60 days after treatment. Results were based on 152 patients who completed the study. 4. A sharp decrease in the proportion of clinical signs and symptoms was observed in all groups immediately after treatment. Ova disappeared from the stools of all patients in the single- and double-dose groups. Thirty days after treatment, ova were identified in the stools of two patients in the triple-dose group who received a second course of triclabendazole. 5. All cases were cured on day 60. However, the cure rate was lower when the patients with suggestive fascioliasis were included in the analysis. The cure rate was not significantly different (P > 0.05) among the three dose groups. No cases of toxic hepatitis were observed. 6. In conclusion, oral administration of 10 mg/kg of the human pharmaceutical preparation of triclabendazole for 1-3 days is safe and effective in the treatment of human fascioliasis.

Prolonged neonatal jaundice: When to worry and what to do

Neonatal jaundice persisting beyond 14 days of age is a common clinical scenario. The vast majority of affected children have a benign unconjugated hyperbilirubinemia, but included in this clinical presentation is a group of neonates with conjugated hyperbilirubinemia and liver disease. Early identification of liver disease improves the infant's outcome, especially for those with extrahepatic biliary atresia. The present paper reviews the approach to the neonate with prolonged jaundice, including clinical presentation, when to proceed with initial investigations, timing of referral, further investigations and management, and provides an overview of the more common causes of neonatal cholestatic liver disease.

Liver disease is a major cause of mortality following allogeneic bone-marrow transplantation

BACKGROUND

Liver disease is an important cause of morbidity and mortality among recipients of bone-marrow transplantation (BMT). The aim of this retrospective study was to determine the incidence, risk factors and clinical evolution of liver disease following allogeneic BMT.

METHODS

A total of 103 patients (mean age 22.8 years (SD 10.9); 31.1% aged < 18 years; 66% males) transplanted in a single institution were enrolled. Data on donors and recipients were collected, including hematological disease, alanine transaminase, alkaline phosphatase, bilirubin, hepatitis B virus (HBV) and hepatitis C virus (HCV) markers (including HBV-DNA and HCV-RNA).

RESULTS

Fifty six of 103 patients died, with liver disease the main cause of death (27 of 56, 48%). Overall the incidence of liver failure attributed to hepatic graft-versus-host-disease (GVHD) was 22.3% (23 of 103; 74% HBV/HCV infected) and veno-occlusive disease (VOD) was 9.7% (10 of 103; 80% HBV/HCV infected). Fourteen patients had hepatitis reactivations (four hepatic GVHD and three VOD). Donors' HCV-RNA status and serum bilirubin above 2 mg/dl were predictive of hepatic GVHD [adjusted odds ratio (AOR) 11.1, 95% confidence interval (CI) 0.99-33.12; AOR 3.93, 95% CI 1.09-14.62; P < 0.05, respectively] and an abnormal alkaline phosphatase could predict severe liver disease (AOR 2.78, 95% CI 1.01-7.54; P < 0.05). Development of severe liver disease (hepatic GVHD or VOD) was a significant predictor of mortality (AOR 4.57, 95% CI 1.09-20.32; P < 0.05) with a low probability of survival (19.3%, SD 7.9%) compared with those without liver disease (52.1%, SD 7.6%; log-rank P = 0.0003).

CONCLUSIONS

Hepatic GVHD is a common complication following BMT and an important cause of liver-related mortality. The high prevalence of HCV and HBV may have contributed to the outcome of hepatic GVHD and VOD. Therefore, antiviral therapy should be considered early to prevent relentless progression of liver disease.

Neonatal cholestasis

Any infant who is jaundiced beyond two to three weeks of life should be evaluated for neonatal cholestasis. Neonatal cholestasis is defined as accumulation of bile substances in blood due to impaired excretion. These infants should always have fractionated serum bilirubin levels checked to differentiate the conjugated hyperbilirubinemia of cholestasis from unconjugated hyperbilirubinemia that is usually benign and spontaneously resolves. Conjugated hyperbilirubinemia, pale stools and dark urine are the cardinal features of neonatal cholestasis. The differential diagnosis of cholestasis is extensive and a systematic approach is helpful to quickly establish the diagnosis. Biliary atresia is a common cause of neonatal cholestasis and affected infants need surgery before 60 days of life for better prognosis. Premature infants have multifactorial cholestasis and need a modified approach to the evaluation of cholestasis. Management of cholestasis is mostly supportive, consisting of medical management of complications of chronic cholestasis like pruritus and nutritional support for malabsorption and vitamin deficiency.

Guideline for the evaluation of cholestatic jaundice in infants: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition

For the primary care provider, cholestatic jaundice in infancy, defined as jaundice caused by an elevated conjugated bilirubin, is an uncommon but potentially serious problem that indicates hepatobiliary dysfunction. Early detection of cholestatic jaundice by the primary care physician and timely, accurate diagnosis by the pediatric gastroenterologist are important for successful treatment and a favorable prognosis. The Cholestasis Guideline Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition has formulated a clinical practice guideline for the diagnostic evaluation of cholestatic jaundice in the infant. The Cholestasis Guideline Committee, consisting of a primary care pediatrician, a clinical epidemiologist (who also practices primary care pediatrics), and five pediatric gastroenterologists, based its recommendations on a comprehensive and systematic review of the medical literature integrated with expert opinion. Consensus was achieved through the Nominal Group Technique, a structured quantitative method. The Committee examined the value of diagnostic tests commonly used for the evaluation of cholestatic jaundice and how those interventions can be applied to clinical situations in the infant. The guideline provides recommendations for management by the primary care provider, indications for consultation by a pediatric gastroenterologist, and recommendations for management by the pediatric gastroenterologist. The Cholestasis Guideline Committee recommends that any infant noted to be jaundiced at 2 weeks of age be evaluated for cholestasis with measurement of total and direct serum bilirubin. However, breast-fed infants who can be reliably monitored and who have an otherwise normal history (no dark urine or light stools) and physical examination may be asked to return at 3 weeks of age and, if jaundice persists, have measurement of total and direct serum bilirubin at that time. This document represents the official recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition on the evaluation of cholestatic jaundice in infants. The American Academy of Pediatrics has also endorsed these recommendations. These recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the care of all patients with this problem.

Biliary atresia

Biliary atresia (BA) is a congenital obliterative cholangiopathy of unknown aetiology, affecting both the intra- and extrahepatic bile ducts. Although relatively rare, BA must be excluded in any infant with conjugated hyperbilirubinaemia since the prognosis is improved by early diagnosis and prompt surgery. At least two phenotypes of BA are currently recognized; the syndromic variety is associated with other congenital anomalies and a poorer outcome. The results of treatment have steadily improved and, with a combination of timely expert surgery (Kasai portoenterostomy) and liver transplantation in specialist centres, good quality long-term survival is now possible in more than 90% of affected patients. A better understanding of the aetiology of BA and the pathogenesis of hepatic fibrosis is needed in order to develop new therapeutic strategies.

Sonographic diagnosis of biliary atresia in pediatric patients using the "triangular cord" sign versus gallbladder length and contraction

OBJECTIVE

A retrospective review was performed to evaluate the importance of the "triangular cord" sign in comparison with gallbladder length and contraction for the diagnosis of biliary atresia in pediatric patients.

MATERIALS AND METHODS

Fifty-five fasting infants with cholestatic jaundice were examined on sonography. The examinations focused on the visualization of the triangular cord sign and assessment of gallbladder length and contraction. The diagnosis of neonatal hepatitis or of other causes of infantile cholestasis was made if symptom resolution occurred during follow-up.

RESULTS

A triangular cord sign was found in 27 of 29 infants with biliary atresia and in one of 26 infants with neonatal hepatitis or other causes of infantile cholestasis. The diagnostic accuracy was 95%, sensitivity was 93%, and specificity was 96%. The gallbladder was thought to be abnormal if it was less than 1.5 cm long, was not detectable, or was detectable but had no lumen. The gallbladder was abnormal in 21 of 29 infants with biliary atresia, whereas it was abnormal in eight of 26 infants with neonatal hepatitis or other causes of infantile cholestasis. The diagnostic accuracy was 71%, sensitivity was 72%, and specificity was 69%. The gallbladder was detectable on sonography in 13 infants with biliary atresia and 26 infants with neonatal hepatitis or other causes of infantile cholestasis. Gallbladder contraction was not confirmed in 11 of 13 infants with biliary atresia and seven of 26 infants with neonatal hepatitis or other causes of infantile cholestasis. The diagnostic accuracy was 77%, sensitivity was 85%, and specificity was 73%.

CONCLUSION

The triangular cord sign was a more useful sonographic finding for diagnosing biliary atresia than gallbladder length and contraction.

Clastogenic effects of the fasciolicide drug fasinex on river buffalo lymphocyte cultures in vitro

Fasinex (triclabendazole) has been reported to be an active fasciolocidal agent used in humans and in farm animals. The clastogenic effects of fasinex were tested in lymphocyte cultures of the river buffalo at three final concentrations: 25, 50 and 100 microg/ml. Chromosomal aberrations, sister chromatid exchanges and micronucleus formation are the three cytogenetic parameters used in this study. The results demonstrated that the number of cells with different types of chromosomal aberrations, including chromatid breaks and gaps, isochromatid breaks and gaps and polyploidy, was increased significantly in cultures treated with different doses of fasinex compared to the control. This increase was dose-dependent where there was a positive correlation between increased drug concentration and induction of chromosomal aberrations. The frequency of sister chromatid exchanges and the formation of micronuclei in all lymphocyte cultures treated with different doses of fasinex were increased significantly compared to the control; these increases were also dose-dependent. In conclusion, the three cytogenetic parameters used to evaluate the effect of fasinex revealed that the drug has a strong clastogenic effect on river buffalo lymphocytes in vitro.

Triangular cord sign and ultrasound features of the gall bladder in infants with biliary atresia

The aim of this study was to reassess the accuracy of the triangular cord sign, the triangular cord sign coupled with abnormal gall-bladder length, and an irregular gall-bladder wall in the diagnosis of biliary atresia. The ultrasonograms of 46 infants with cholestatic jaundice were reviewed for the triangular cord sign, gall-bladder length and gall-bladder wall without knowledge of the clinical data. Of the 23 infants with biliary atresia, 22 had the triangular cord sign whereas 17 infants with other causes of cholestatic jaundice did not have the triangular cord sign. The sensitivity, specificity, accuracy and positive predictive value of the triangular cord sign in the diagnosis of biliary atresia were 95.7, 73.9, 84.8 and 78.6%, respectively. The sensitivity, specificity, accuracy and positive predictive value of the triangular cord sign coupled with abnormal gall-bladder length in the diagnosis of biliary atresia were all 95.7%. Gall-bladder wall irregularity was seen in seven of 14 infants (50%) with biliary atresia whose gall bladders contained bile on ultrasound and in two of 22 infants (9.1%) without biliary atresia whose gall bladders contained bile on ultrasound. At the medical centre where this study was performed and where infants present with cholestatic jaundice at an advanced stage, the ultrasonographic triangular cord sign coupled with abnormal gall-bladder length is more reliable than the ultrasonographic triangular cord sign alone or gall-bladder wall irregularity in the diagnosis of biliary atresia.

Pediatric hepatobiliary disease

Advances in the field of pediatric hepatobiliary disease have provided insights into disease mechanisms and offered potential tools for early diagnosis or predicting prognosis of devastating diseases. This review summarizes recent major advances in seven areas in the field of pediatric hepatobiliary disease, including extrahepatic biliary atresia, liver disease and transplantation in cystic fibrosis, growth after liver transplantation, predicting acetaminophen hepatotoxicity, treatment of chronic hepatitis B, hepatocellular carcinoma, and liver disease in neonatal lupus erythematosus.

Hepatitis B and C infection in children undergoing chemotherapy or bone marrow transplantation

Despite preventive measures, patients who have cancer or who undergo bone marrow transplantation remain at higher risk of viral infection since they often receive multiple blood products. This category of patients also includes subjects from countries that are highly endemic for hepatitis B virus and hepatitis C virus infection and who travel to developed countries for specialized treatment. This review discusses the current opinions concerning the diagnostic, clinical, and therapeutic aspects of hepatitis B and C virus infection in different groups of patients: children with chronic infection before chemotherapy, children infected during chemotherapy or bone marrow transplantation, and patients with chronic infection after the end of treatment.

Transmission of HCV infection among long-term hospitalized onco-haematological patients

Hepatitis C virus (HCV) infection is becoming a substantial problem in long-term hospitalized patients. Onco-haematological patients undergoing chemotherapy are especially prone to HCV infection. These patients are usually immunosuppressed and therefore antibodies to HCV are not produced despite the presence of HCV RNA in peripheral blood. The aim of the study was to see how often long-term hospitalized patients acquired HCV infection, and what were the possible sources and routes of virus transmission. The study involved 129 children with lymphoproliferative diseases, 36 patients with solid tumours, and 61 healthcare workers from onco-haematological wards. All were HCV RNA and anti-HCV negative at the time of first hospitalization. During a two and a half-year follow-up study among 165 onco-haematological patients, HCV RNA appeared in 87 in subsequent hospitalizations. The majority of infections were (82/87) were 1a genotype, 2 were 1b, 1 was 1a + 1b and 1 was 1a + 3a. In an attempt to establish the origin of HCV infection, healthcare workers were screened for HCV genotyping. All HCV-infected staff working on wards had the same genotype (1a). None of the staff was infected with 1b genotype. As the most prevalent genotype in Polish blood donors is 1b, HCV infection in onco-haematological patients is most likely due to horizontal transmission, probably involving genotype 1a, and potential horizontal transmission of HCV is implied by the presence of 1a genotype of HCV in saliva and urine of selected patients. Spread of hospital HCV infection among children may be facilitated by micro-injury of the skin and mucosa. Early detection of HCV RNA is important in such immunosuppressed patients, as they are not able to produce anti-HCV antibodies. This may enable the introduction of prophylactic steps to prevent the spread of HCV infection by horizontal transmission.

Pancreas and biliary system: imaging of developmental anomalies and diseases unique to children

The focus of this article is on the development of the pancreas and biliary system, with a review of the most common congenital anomalies affecting the pancreas and biliary tree, including pancreas divisum, annular pancreas, congenital shortening of the pancreas, and choledochal cysts. Additionally, biliary atresia and pancreatoblastoma--both diseases of the pancreas and biliary system that almost exclusively affect children--are considered, with a discussion regarding the clinical presentation and imaging appearances of these disorders.

A PCR-RFLP assay for the distinction between Fasciola hepatica and Fasciola gigantica

Fascioliasis is of well-known veterinary importance and an increasing human health problem, with reported cases in the five continents. The causative agents, Fasciola hepatica and Fasciola gigantica, present geographical distributions, which overlap in many regions of Africa and Asia, and in which the differentiation of both species is usually difficult because of the many variations in their morphological characteristics. Moreover, in humans, liver fluke classification cannot be achieved by clinical, pathological, coprological or immunological methods. The differential diagnosis between F. hepatica and F. gigantica infection is very important because of their different transmission and epidemiological characteristics. A simple and rapid PCR-restriction fragment length polymorphism (RFLP) assay, using the common restriction enzymes Ava II and Dra II, is described to distinguish between both fasciolid species. It is based on a 618-bp-long sequence of the 28S rRNA gene recently obtained from liver fluke populations of South America, Europe and Africa. This sequence showed a few nucleotide differences between both fasciolids and no intraspecific variations within each species. This assay provides unambiguous results and may be useful for both individual subject diagnosis and epidemiological surveys of humans and animals in endemic regions of sympatry.

A praziquantel-ineffective fascioliasis case successfully treated with triclabendazole

Human fascioliasis cases in Japan have been reported infrequently and the most appropriate therapy for this disease remains to be determined. This case report describes a patient with the infection unsuccessfully treated with multiple high doses of praziquantel for over 1 year and eventually cured by the administration of triclabendazole in two single doses of 10 mg/kg and 12.5 mg/kg 5 months apart.

Cholestatic syndromes

Further insights into the molecular regulation of bile acid transport and metabolism have provided the basis for a better understanding of the pathogenesis of cholestatic liver diseases. Novel insights into the mechanisms of action of ursodeoxycholic acid should advance our understanding of the treatment of cholestatic liver diseases. Mutations of transporter genes can cause hereditary cholestatic syndromes in both infants and adults as well as cholesterol gallstone disease. Important studies have been published on the pathogenesis, clinical features, and treatment of primary biliary cirrhosis, drug-induced cholestasis, and cholestasis of pregnancy.

Synthesis and fasciolicidal activity of 5-chloro-2-methylthio-6-(1-naphthyloxy)-1H-benzimidazole

The synthesis and fasciolicidal activity of 5-chloro-2-methylthio-6-(1-naphthyloxy)-1H-benzimidazole (6) is described. Compound 6 showed 100% activity in vitro at 146.70 and 29.34 microM concentrations. It also completely removed 3-d and 10-week-old Fasciola hepatica in sheep at a dose of 15 mg/kg.

Neonatal cholestasis

Neonatal cholestasis must always be considered in a newborn who is jaundiced for more than 14-21 days and a measurement of the serum total and conjugated bilirubin in these infants is mandatory. Conjugated hyperbilirubinaemia, dark urine and pale stools are pathognomic of the neonatal hepatitis syndrome which should be investigated urgently. The neonatal hepatitis syndrome has many causes and should be investigated using a structured protocol. The most important condition in the differential diagnosis is biliary atresia and affected infants require a Kasai portoenterostomy performed by an experienced surgeon, ideally before the infant is 60 days old. A modified evaluation schedule should be used for preterm infants who have required neonatal intensive care. Genetic causes of the neonatal hepatitis syndrome are increasingly recognized and early diagnosis facilitates genetic counselling and, in some situations, specific treatment. The management of cholestasis is largely supportive, consisting of aggressive nutritional support with particular attention to fat-soluble vitamin status. The use of ursodeoxycholic acid is associated with improvement in biochemical measures of cholestasis and may improve the natural history of cholestasis in some circumstances. Outcome is dependent on aetiology. In idiopathic neonatal hepatitis more than 90% make a complete biochemical and d clinical recovery.

Update on the etiologies and management of neonatal cholestasis

The early detection of cholestatic liver disease is one of the major challenges facing pediatricians when evaluating the jaundiced infant. Early recognition of liver disease greatly facilitates the care and outcome of infants, because several serious life-threatening disorders may have cholestasis as a major presenting sign of underlying neonatal liver disease. A key component of the work-up is measurement of serum conjugated bilirubin levels, which if elevated should prompt the clinician to initiate a work-up to determine the cause of neonatal cholestasis. In general, if a patient is developing progressive jaundice soon after birth, is still jaundiced at 2 weeks of life, or develops jaundice within the first month of life, a work-up for neonatal cholestasis should begin. A number of previously undiagnosed causes of neonatal cholestasis are beginning to be assigned genetic and infectious etiologies, with significant implications for the work-up and management of cholestatic infants.

Conservative management of biliary obstruction due to Fasciola hepatica

We report a case of temporary biliary obstruction due to fascioliasis. This case report shows that in Central Europe, fascioliasis is one of the differential diagnoses of abdominal pain, especially if it is associated with eosinophilia. Successful medical treatment is possible even with obstruction of the bile duct.

Molecular cloning and expression of Cu/Zn-containing superoxide dismutase from Fasciola hepatica

The cytosolic superoxide dismutase (SOD) of Fasciola hepatica, a causative agent of fascioliasis, was purified and characterized. The enzyme consists of two identical subunits, each with an apparent molecular mass of 17.5 kDa. An analysis of the enzyme's primary structure and inhibition studies revealed that the enzyme is a copper/zinc-containing SOD (Cu/Zn-SOD). The enzyme activity was relatively stable in a broad pH range, from pH 7.0 to 10.0, and the enzyme showed maximum activity at pH 7.5. This enzyme also displayed strong antigenicity against sera of bovine and human subjects with fascioliasis. The SOD gene fragment was amplified by PCR with degenerate oligonucleotide primers derived from amino acid sequences conserved in the Cu/Zn-SODs of other organisms. An F. hepatica cDNA library was screened with the SOD gene fragment as a probe. As a result, a complete gene encoding the Cu/Zn-SOD was identified, and its nucleotide sequence was determined. The gene had an open reading frame of 438 bp and 146 deduced amino acids. Comparison of the deduced amino acid sequence of the enzyme with previously reported Cu/Zn-SOD amino acid sequences revealed considerably high homologies. The coding region of the F. hepatica Cu/Zn-SOD was cloned and expressed in Escherichia coli. Staining of native polyacrylamide gel for SOD activity of the expressed protein revealed SOD activity that was inactivated by potassium cyanide and hydrogen peroxide but not by sodium azide. This means that the presence of the recombinant fusion protein is indicative of Cu/Zn-SOD. The expressed protein also reacted with sera of bovine and human subjects with fascioliasis, but it did not react with sera of uninfected bovine and human subjects.

Fascioliasis: sonographic abnormalities of the biliary tract and evolution after treatment with triclabendazole

Diagnosis of infection with the liver fluke Fasciola hepatica is usually difficult. Ultrasonography (US) might be a useful diagnostic alternative, and we assessed the value of sequential US in the diagnosis and monitoring of fascioliasis in 76 patients at baseline and for 60 days after treatment with triclabendazole. At baseline, biliary abnormalities were observed in 52 patients. Crescent-shaped parasites were seen in 11 patients; in 2 cases parasites were spontaneously moving and in 4 patients parasites were motionless. Postprandial examination revealed parasites adhering to the gallbladder wall in a further 5 cases. In 3 further cases, gallbladder contents were mobile but did not sediment downwards after patients changed position. Non-specific abnormalities were: impaired gallbladder contractility (n = 23), gallbladder tenderness (n = 19), debris (n = 6), calculi (n = 5), wall thickening (n = 2) and bile duct dilatation (n = 12). During day 1-7, Fasciola-like crescents in the gallbladder or passing through the bile duct were detected in another 15 patients, impaired gallbladder contractility in 16, gallbladder tenderness in 16, and bile duct dilatation in an additional 28 patients. Thirty-two patients with these US abnormalities experienced colic-like abdominal pain accompanied by increased alkaline phosphatase in 25 cases. During day 30-60, abnormalities regressed completely in 45 patients; 2/6 triclabendazole failures were evident by detection of living parasites. Biliary tract abnormalities are frequently observed by US, but the detection-rate of Fasciola hepatica is disappointingly low despite the parasite's relatively large size. US findings must therefore be interpreted together with other clinical measurements. The visualization of parasites being expelled through the dilated common bile duct allowed the causal interpretation of post-therapeutic abdominal pain and increase of liver enzymes. When triclabendazole is given on suspicion, visualization of worm expulsion and bile duct dilatation by US may be used to confirm diagnosis.