Thiopurine S-methyltransferase (TPMT) genotype does not predict adverse drug reactions to thiopurine drugs in patients with inflammatory bowel disease.

BACKGROUND: Azathioprine and mercaptopurine (MP) are well established treatments for inflammatory bowel disease but they have severe adverse effects that prevent their use in some patients. The likelihood and type of adverse effect may relate to thiopurine methyltransferase (TPMT) enzyme activity and genotype. AIM: To compare the TPMT genotype frequencies in patients with inflammatory bowel disease who have had severe adverse effects to those who tolerate azathioprine or MP (controls). METHODS: Patients with inflammatory bowel disease who had been treated with azathioprine or MP in Christchurch between 1996 and 2002 were identified. Patients with adverse effects, and controls, were invited to provide a peripheral blood sample for analysis of TPMT genotype. The genotype frequencies were then compared between the two groups. RESULTS: Fifty-six patients were identified with adverse effects requiring cessation of therapy, of which 50 were genotyped. Reactions included allergic-type (25%), hepatitis (33%), nausea/vomiting (14%), bone marrow suppression (10%), pancreatitis (6%) and other (12%). Five of 50 patients with reactions had TPMT genotype *1/*3, one had *3/*3, and the rest had the wildtype genotype *1/*1. The patient with genotype *3/*3 had severe pancytopenia requiring hospitalization. Three of 50 controls had the *1/*3 genotype and the rest were *1/*1. CONCLUSIONS: The TPMT allele frequency in our population with inflammatory bowel disease is similar to that reported elsewhere. There was a slight trend for more frequent TPMT mutations in the patients with adverse reactions, but this was not statistically significant. Most patients with reactions did not have gene mutations.

Haemochromatosis gene mutations Cys282Tyr and His63Asp are not increased in Type 2 diabetic patients compared with the Canterbury (New Zealand) general population.

Genetic predisposition to haemochromatosis may be an important aetiological factor in some cases of Type 2 diabetes. Our aim was therefore to test the hypothesis that the haemochromatosis gene mutations Cys282Tyr and His63Asp are more prevalent in Type 2 diabetic patients compared with the Canterbury, New Zealand general population. We studied 230 consecutive patients referred to the Diabetes Services with age > or = 30 years and considered to have Type 2 diabetes. DNA was extracted from whole blood and amplified by polymerase chain reaction prior to restriction fragment length polymorphism analysis. The frequency of the mutations was compared with that observed previously in 1064 subjects from the Canterbury general population by chi2 testing. Iron was measured by a colorimetric method, transferrin by rate nephelometry and ferritin by immunoassay. There were 2/230 (0.8%) Cys282Tyr homozygous subjects in the diabetic group compared with 5/1064 (0.5%) NS in the general population. Although there was a trend to lower incidence of Cys282Tyr heterozygosity in the diabetic group, there was no significant difference for any of the six genotype frequencies between the two groups. Haemochromatosis gene mutations Cys282Tyr and His63Asp are therefore not increased in Type 2 diabetics compared with the general population. Transferrin saturation was a sensitive marker (100%) of genetic haemochromatosis, although ferritin had low specificity (77.8%). Genetic susceptibility to haemochromatosis is not an important aetiological factor for diabetes, and targeted screening of diabetic patients for haemochromatosis is not indicated.

Isolation and characterisation of cosmids to intervals within a 4.5Mb region at 6p21.3.

The gene responsible for hereditary haemochromatosis (HH) has recently been identified. One mutation in this gene, termed HFE, has been found in all Australian HH patients. We previously identified a predominant HH ancestral haplotype covering 4.5Mb at 6p21.3, and showed that patients with two copies of this haplotype express a more severe form of the disorder. One key question to now be resolved is why haplotype related variation in phenotypic expression of HH is present if all patients tested have the same HFE mutation. A cosmid resource covering the 4.5Mb HH ancestral haplo type region was obtained. These cosmids provide the material for the completion of a transcript map of this region, and will assist the identification of candidate modifiers of HFE expression.

Postmortem blood free and total morphine concentrations in medical examiner cases.

This purpose of this study was to determine the relationships between postmortem free morphine and total morphine levels in a large series of medical examiner morphine and heroin related deaths. Free morphine, total morphine, and 6-monoacetylmorphine (6-MAM) concentrations were measured by gas chromatography-mass spectrometry (GC-MS) in 87 medical examiner cases over 20 months. The mean total morphine concentration, mean free morphine concentration, and mean percent free morphine for all cases were: 2.3 mg/L (SD 5.2 mg/L), 0.5 mg/L (SD 1.6 mg/L), and 19.4% (SD 22.8%); respectively. Regression analyses showed weak correlations between total and free morphine concentrations over the entire concentration range (0 to 36.6 m/L, r = 0.603, n = 91) and over a subset concentration range of 0 to 1.0 mg/L (r = 0.369, n = 54). Twenty-three out of 56 (41%) tested positive for 6-MAM, indicative heroin abuse cases. Lower total and free morphine concentrations and a higher percent free morphine were found in individuals with detectable 6-MAM. Comparing blood concentrations for cases with and without detectable 6-MAM demonstrated mean total morphine concentrations of 0.9 mg/L versus 2.1 mg/L (p = 0.05), mean free morphine concentrations of 0.3 mg/L versus 0.4 mg/L (p = 0.21), and mean percent free morphine of 34.7% versus 13.7% (p < 0.003), respectively. Our findings demonstrate higher free to total morphine ratios in individuals with detectable 6-MAM than in individuals without 6-MAM. The database established in this study may assist medical examiners in the evaluation of postmortem blood opiates regarding the cause of death in opiate related ingestion cases.

Pyogenic liver abscesses: a retrospective review of 24 cases.

OBJECTS: to review our experience of pyogenic liver abscess with attention to the value of ultrasound and computerised tomography, and the duration of antimicrobial therapy. METHOD: retrospective review of all pyogenic liver abscesses in Christchurch hospitals between 1972 and 1989. RESULTS: twenty-four cases were identified. The presentation of these cases was typical of those described in other series. Ultrasound scanning was positive in 69% of cases, and computerised tomography in 94%. Enteric organisms were isolated from blood or abscess cavities in all but two cases. Two patients died soon after admission and three were treated with antimicrobial therapy alone. The remainder underwent either a percutaneous or surgical drainage procedure, and received antimicrobial therapy. The antimicrobial therapy was clearly inappropriate in two patients. Eight patients (67%) with single abscesses received less than 10 days of antimicrobial therapy. Four patients (50%) with multiple abscesses received less than 18 days therapy. No patient relapsed. CONCLUSIONS: ultrasound is a convenient initial imaging technique, but may give false negative results. Computerised tomography should be done promptly if clinical suspicion of a liver abscess persists. Both surgical and percutaneous drainage techniques gave good results in combination with antimicrobial therapy. It is probably unnecessary to give prolonged courses of antimicrobial therapy following drainage of single liver abscess, provided there is rapid resolution. Multiple abscesses, or those which are not drained, may require longer courses of antimicrobial therapy.

Evaluation of alpha interferon for the treatment of chronic hepatitis B infection in Christchurch.

AIM: To evaluate alpha interferon for the treatment of chronic replicative hepatitis B infection in Christchurch patients. METHODS: Ten patients were divided into two groups depending upon whether their average pretreatment ALT levels were greater than twice the upper limit of normal (group 1, 6 subjects) or less than twice the upper limit of normal (group 2, 4 subjects). Interferon alpha-2a (4.5 mega units) was administered three times a week for 24 weeks with the addition of a preceding priming course of prednisone in group 2. RESULTS: At 6 months post treatment only one patient in group 1 had seroconverted (HBeAg to anti-HBe), however, the remaining five patients seroconverted from 18-32 months after therapy. This response was associated with normalisation of the transaminases and in 5/6 subjects a fall in the HBV DNA levels. In group 2 one subject seroconverted by 6 months despite a shortened course of Interferon. A delayed seroconversion (18 months) was observed in one patient and another had a partial response with the development of anti-HBe but associated with persistence of HBeAg. The remaining patient has not responded. CONCLUSIONS: Interferon alpha-2a was effective in promoting a seroconversion HBeAg to anti-HBe in patients with chronic hepatitis B and transaminases elevated to twice the upper limit of normal, although in most cases this response was delayed. Larger studies will be required to determine the role of steroid priming in those with less active disease.

The prevalence of antibodies to hepatitis C virus in patients with chronic liver disease.

OBJECT: to determine the prevalence of antibodies to hepatitis C virus in selected groups of patients with chronic liver disease. METHODS: serum specimens were obtained from 39 patients with chronic liver function abnormalities of uncertain cause (group A), from 15 patients with autoimmune chronic active hepatitis (group B) and from 10 patients with chronic hepatitis B (group C). In an extension of the study, serum was collected from sexual partners of patients found to be HCV seropositive. A second generation ELISA assay (Abbott) was used to analyse the specimens. RESULTS: ten patients (26%) in group A were seropositive, one (7%) in group B and three (30%) in group C. Risk factors for infection included blood transfusion in three, intravenous drug use in six (including the only positive patient in group B) and both factors in another patient. Only one of the 10 sexual partners tested was positive but this subject was also an intravenous drug user. CONCLUSIONS: hepatitis C virus is a significant cause of chronic liver disease in Christchurch. Important risk factors include blood transfusion and intravenous drug use although sporadic cases occur. Transmission to sexual partners is uncommon. The second generation assay does not appear to give false positive results in autoimmune chronic active hepatitis.

Gallstone prevalence in Christchurch: risk factors and clinical significance.

AIMS: To determine the frequency, risk factors and clinical significance of gallstones in a New Zealand population. METHODS: One thousand names were randomly selected from the Christchurch electoral rolls to recruit controls for a study on the prevalence of gallstones in diabetics. Three hundred and eighteen subjects (169 females, 149 males) were recruited and in this study we analyse this control group for gallstone disease. All subjects completed a questionnaire, provided a fasting blood sample and underwent an ultrasound examination of their gallbladder unless they had previously undergone a cholecystectomy. RESULTS: Overall gallstone disease, defined as previous cholecystectomy or a positive scan for gallstones was seen in 20.75% of the 318 subjects recruited. Gallstone disease was more frequent in females (23.1%) compared to males (18.1%) but this difference was not statistically significant. For both genders there was a significant increase in gallstones with age. On univariate analysis, risk factors for gallstone disease included age, increased body mass index, family history of gallstones and decreased alcohol intake in females. However, only age and family history were significant on multiple logistic regression. There was no difference in the frequency of dyspeptic symptoms or abdominal pain between those with or without gallstones confirmed on scanning. The ratio of cholecystectomy to silent gallstones was higher in females (46.2%) than in males (22.2%). CONCLUSION: Gallstones are prevalent in the New Zealand Community (20.8% overall). Risk factors are increasing age and family history. Gallstones detected on scanning were not associated with an increased incidence of dyspeptic symptoms or abdominal pain.

Investigation of subjects with abnormal iron studies: role of the hepatic iron index.

AIM: Genetic haemochromatosis is a common disorder resulting in increased iron deposition in the liver and other organs but can be difficult to diagnose. The aim of this study was to assess the diagnostic value of the conventional tests for iron overload (percentage saturation of transferrin, serum ferritin and grading of iron staining on liver biopsy) and compare these with the newer quantitative biochemical measurements of liver iron. METHOD: A retrospective analysis was made of 108 consecutive patients referred for quantitative liver iron measurements. Iron studies were obtained in 66 of the 108 subjects of whom 60 had abnormal screening tests defined as percent saturation of transferrin (> 60%) and/or ferritin > 350 micrograms/L for females and > 450 micrograms/L for males. Based on clinical features, biochemical data and treatment outcome these 60 subjects were classified as either genetic haemochromatosis, nongenetic haemochromatosis or indeterminate. One patient with treated genetic haemochromatosis was excluded from subsequent analysis. RESULTS: Although the serum ferritin (p < 0.002), percentage saturation of transferrin (p < 0.001), histological iron grade (p < 0.0001) were significantly higher in the genetic haemochromatosis than nongenetic haemochromatosis group there was considerable overlap. Similarly for the hepatic iron concentration (HIC) (p < 0.0001) overlap occurred. The hepatic iron index (HIC/age) gave the best separation with only three cases being misclassified. A correlation between the HII and histological iron index (visualised iron score corrected for age) in 15 subjects gave an r value of 0.72. CONCLUSION: Based on this study we feel that in addition to visual grading of iron in liver biopsies, the hepatic iron index is helpful in establishing a diagnosis of genetic haemochromatosis.

Seroprevalence of Helicobacter pylori in the adult population of Christchurch: risk factors and relationship to dyspeptic symptoms and iron studies.

AIM: To determine the prevalence of Helicobacter pylori infection in subjects randomly selected from the Christchurch population and to determine the risk factors and symptoms related to the infection. METHODS: A list of names was randomly generated from the 1996 electoral roll and subjects were sequentially contacted and invited to participate. A questionnaire on dyspeptic symptoms was completed and the subject's serum was analysed for H. pylori antibodies using the Roche method. Equivocal samples were retested by the Meridian method. RESULTS: One thousand and sixty-four subjects participated in the study. In four subjects results for H. pylori were indeterminate and these subjects were excluded from analysis. Of the remaining 1060 subjects, 254 (24.0%) were seropositive for H. pylori. The seropositivity in males (n=444) was 25.9% and in females (n=616) 22.6%. On multivariate analysis age, ethnicity, low income and smoking > 20 cigarettes per day were all independent predictors of H. pylori seropositivity. H. pylori positive subjects had shorter stature compared to those who were seronegative. The symptom scores for dyspepsia were similar in both the seropositive and seronegative subjects. In males the serum iron levels were lower in seropositive subjects but there were no significant differences in serum ferritin in either males or females between seropositive and seronegative subjects. CONCLUSION: H. pylori is a common infection in the Christchurch community with the prevalence increasing significantly with age. H. pylori positive subjects had shorter stature and in males lower serum iron levels were observed. Infection was not associated with an increased risk of dyspeptic symptoms.

Treatment of chronic hepatitis C with interferon alpha.

AIM: To evaluate the response to interferon alpha in patients with chronic hepatitis C in Christchurch. METHOD: Fifteen patients with chronic HCV were given interferon alpha 3 million units subcutaneously three times a week for up to 24 weeks. A complete and partial biochemical response was defined by relative changes in the serum alanine aminotransferase (ALT) during the treatment period. Detection of HCV RNA by the polymerase chain reaction was used to determine the virological response to treatment. RESULT: A complete or partial response was seen in nine of the 15 patients (60%). Histological improvement was demonstrated in all patients for whom paired liver biopsies were taken. Following treatment two of the five complete responders have shown a sustained biochemical response but only one has remained PCR negative, ie, a sustained virological responder. The other three, complete responders and all four partial responders relapsed. CONCLUSION: The response to treatment and relapse was comparable with other studies. It remains to be shown whether investigation of the viral titre and/or viral type will help to explain the high relapse rate in these patients with chronic HCV.

Viral hepatitis in the Christchurch community.

AIM: To determine the relative frequency of known causes of viral hepatitis in the Christchurch community. METHODS: Serum samples were collected at a private laboratory from patients aged 15-75 years who had an elevated transaminase of at least twice normal. RESULTS: One hundred and thirty-three subjects entered the study of whom 32 were positive for Epstein Barr virus, three for cytomegalovirus, nine for hepatitis A virus, and eight for hepatitis B virus. Paired convalescent samples were obtained from 64 of the remaining 81 subjects (17 lost or declined) and seven of these were positive for hepatitis C. Assuming a similar percentage in the lost/declined group this corrects to nine. CONCLUSION: The relative frequency of viral agents causing hepatitis was Epstein Barr virus 52%, cytomegalovirus 5%, hepatitis A virus 15%, hepatitis B virus 13% and hepatitis C virus 15%. Hepatitis C virus is a common cause of viral hepatitis in the Christchurch community.

Molecular analysis of HLA-H gene mutations in New Zealand patients with haemochromatosis.

AIM: To determine the frequency of HLA-H gene mutations in New Zealand patients with haemochromatosis. METHODS: The Cys282Tyr and His63Asp mutations in the HLA-H gene were analyzed by polymerase chain reaction, restriction enzyme digestion and electrophoresis in two separate patient groups. The first was a group of 20 Christchurch patients with a definite clinical diagnosis of haemochromatosis. The second group consisted of 33 patients, with a provisional diagnosis of haemochromatosis, attending Dunedin Hospital for therapeutic venesection. RESULTS: All 20 Christchurch patients and 25 of the 33 (76%) Dunedin patients were homozygous for the Cys282Tyr mutation. After review of the clinical data, histology and response to venesection a diagnosis of haemochromatosis could be confidently excluded in six of the remaining eight patients. Despite atypical features, a diagnosis of haemochromatosis could not be excluded in the final two patients, one of whom was a compound heterozygote for the two mutations. CONCLUSIONS: Homozygosity for the Cys282Tyr mutation is closely associated with haemochromatosis in New Zealand patients. Molecular analysis of the HLA-H gene is indicated in the assessment of patients with iron overload including those currently being treated by venesection.

The prevalence of viral hepatitis (HAV, HBV and HCV) in the Christchurch community.

AIM: To determine the prevalence of hepatitis A (HAV), hepatitis B (HBV) and hepatitis C (HCV) in adults randomly selected from the Christchurch community. METHODS: A list of names was randomly generated from the Christchurch electoral roll and subjects were sequentially contacted and invited to participate. A blood sample was taken and tested for hepatitis A (IgG anti-HAV antibody), hepatitis B (HBsAg and anti-HBc) and HCV (anti-HCV antibody) using Abbott Elisa kits. Subjects positive for HBsAg were also tested for HBeAg/HBV DNA. Those positive for anti-HBc were tested for anti-HBs. HCV antibody positive samples were tested for HCV RNA using PCR. RESULTS: 1064 subjects (30.3% of those invited) participated in the study. The prevalence of HAV antibodies was 27.9%, and increased with age. The overall prevalence of HBV markers was 42/1064 (4.2%), and of these 0.3% were HBsAg positive and 3.9% were considered immune. No gender or ethnic differences in these proportions were observed. The seroprevalence of HVC antibody was 3/1064 (0.3%), two of whom were also PCR positive for HCV RNA. CONCLUSION: In the Christchurch community there was a high prevalence of antibodies to HAV, which increased with age. The prevalence of HBsAg and antibody to HCV were both low at 0.3%.

Review: the surgical management of ulcerative colitis.

The treatment of ulcerative colitis requires careful review of the medical and surgical options. The surgical procedure of choice is proctocolectomy with ileal pouch-anal anastomosis. This procedure removes the diseased mucosa, effectively curing the disease whilst maintaining the normal route of defecation and continence. Other surgical options that may be considered in selected patients include proctocolectomy with either a Brooke ileostomy or a Kock pouch, and abdominal colectomy with ileorectal anastomosis. The choice of operation requires consideration of the advantages and disadvantages of a particular procedure and must be tailored to an individual patient's needs and circumstances.

The influence of iron on chronic hepatitis C.

It has recently been suggested that the hepatic iron concentration can be used to predict the response to interferon in patients with chronic hepatitis C. An hepatic iron concentration greater than 1100 microg/g appears to identify a group of patients that are unlikely to respond to alpha-interferon. It is not known whether this relationship can be explained by associated variables such as age, gender or disease severity or whether the hepatic iron concentration itself influences the response to interferon. Furthermore, the hepatic iron concentration is of no value in discriminating responders from non-responders in patients with hepatic iron concentrations less than 1100 microg/g. The possibility of improving response rates to interferon by pretreatment venesection needs to be explored but currently only limited data are available. Venesection results in a significant fall in the serum transaminases but the preliminary results regarding the efficacy of subsequent interferon therapy are unclear. Until the results of prospective controlled trials are available it is concluded that the available evidence does not support venesection before interferon therapy for chronic hepatitis C.

Haemochromatosis--a clinical update.

Haemochromatosis is now known to be a common genetic disorder, with a carrier rate of about 1 in 10 in populations of Northern European origin. With early diagnosis and treatment, life expectancy is normal, yet it remains underdiagnosed.

Use of (99m)Tc-DISIDA biliary scanning with morphine provocation for the detection of elevated sphincter of Oddi basal pressure.

BACKGROUND: Endoscopic biliary manometry is useful in the assessment of patients with types II and III sphincter of Oddi dysfunction, but it is time consuming and invasive. AIM: To investigate the role of (99m)Tc-DISIDA scanning, with and without morphine provocation, as a non-invasive investigation in these patients compared with endoscopic biliary manometry. SUBJECTS AND METHODS: A total of 34 patients with a clinical diagnosis of type II (n = 21) or III (n = 13) sphincter of Oddi dysfunction were studied. Biliary scintigraphy with 100 MBq of (99m)Tc-DISIDA was carried out with and without morphine provocation (0.04 mg/kg intravenously) and time/activity curves were compared with the results of subsequent endoscopic biliary manometry. RESULTS: Eighteen (nine type II, nine type III) of the 34 (53%) patients had sphincter of Oddi basal pressures above the upper limit of normal (40 mm Hg). In the standard DISIDA scan without morphine, no significant differences were observed in time to maximal activity (Tmax) or percentage excretion at 45 or 60 minutes between those with normal and those with abnormal biliary manometry. However, following morphine provocation, median percentage excretion at 60 minutes was 4.9% in those with abnormal manometry and 28.2% in the normal manometry group (p = 0.002). Using a cut off value of 15% excretion at 60 minutes, the sensitivity for detecting elevated sphincter of Oddi basal pressure by the morphine augmented DISIDA scan was 83% and specificity was 81%. Also, 14 of the 18 patients with abnormal manometry complained of biliary-type pain after morphine infusion compared with only two of 16 patients in the normal manometry group (p = 0.001). CONCLUSIONS: (99m)Tc-DISIDA with morphine provocation is a useful non-invasive investigation for types II and III sphincter of Oddi dysfunction to detect those with elevated sphincter basal pressures who may respond to endoscopic sphincterotomy.