Indications for liver transplantation in British Columbia's Aboriginal population: a 10-year retrospective analysis

Ethnicity, disease severity, and survival in Canadian patients with primary biliary cholangitis

BACKGROUND AND AIMS

We investigated associations between ethnicity, survival, and disease severity in a diverse Canadian cohort of patients with primary biliary cholangitis (PBC).

APPROACH AND RESULTS

Patients with PBC were included from the Canadian Network for Autoimmune Liver Disease. Ethnicity was defined using a modified list adopted from Statistics Canada, and ethnicities with small samples were grouped. Clinical events were defined as liver decompensation, HCC, liver transplantation, or death. Clinical event-free and liver transplantation-free survival were analyzed using Cox regression. Trajectories of serum liver function tests were assessed over time using mixed-effects regression. Health-related quality of life was assessed using the Short Form 36, the PBC-40 questionnaire, and the 5-D Itch scale and analyzed using mixed-effects regression. The cohort included 1538 patients with PBC from six sites and was comprised of 82% White, 4.7% Indigenous, 5.5% East Asian, 2.6% South Asian, and 5.1% miscellaneous ethnicities. Indigenous patients were the only ethnic group with impaired liver transplant-free and event-free survival compared to White patients (HR, 3.66; 95% CI, 2.23-6.01; HR, 3.09; 95% CI, 1.94-4.92). Indigenous patients were more likely to have a clinical event before diagnosis (10%) than all other ethnic groups despite similar age at diagnosis. Indigenous patients presented with higher alkaline phosphatase, total bilirubin, and GLOBE scores than White patients; and these relative elevations persisted during follow-up.

CONCLUSIONS

Indigenous Canadians with PBC present with advanced disease and have worse long-term outcomes compared to White patients.

End stage liver disease etiology & transplantation referral outcomes of major ethnic groups in British Columbia, Canada: A cohort study

Liver disease etiology and transplantation outcomes may vary by ethnicity. We aimed to determine if disparities exist in our province.We reviewed the provincial database for liver transplant referrals. We stratified cohorts by ethnicity and analyzed disease etiology and outcomes.Four thousand nine hundred sixteen referrals included 220 South Asians, 413 Asians, 235 First Nations (Indigenous), and 2725 Caucasians. Predominant etiologies by ethnicity included alcohol (27.4%) and primary sclerosing cholangitis (PSC) (8.8%) in South Asians, hepatitis B (45.5%) and malignancy (13.9%) in Asians, primary biliary cholangitis (PBC) (33.2%) and autoimmune hepatitis (AIH) (10.8%) in First Nations, and hepatitis C (35.9%) in Caucasians. First Nations had lowest rate of transplantation (30.6%, P = .01) and highest rate of waitlist death (10.6%, P = .03). Median time from referral to transplantation (268 days) did not differ between ethnicities (P = .47). Likelihood of transplantation increased with lower body mass index (BMI) (hazard ratio [HR] 0.99, P = .03), higher model for end stage liver disease (MELD) (HR 1.02, P < .01), or fulminant liver failure (HR 9.47, P < .01). Median time from referral to ineligibility status was 170 days, and shorter time was associated with increased MELD (HR 1.01, P < .01), increased age (HR 1.01, P < .01), fulminant liver failure (HR 2.56, P < .01) or South Asian ethnicity (HR 2.54, P < .01). Competing risks analysis revealed no differences in time to transplant (P = .66) or time to ineligibility (P = .91) but confirmed increased waitlist death for First Nations (P = .04).We have noted emerging trends such as alcohol related liver disease and PSC in South Asians. First Nations have increased autoimmune liver disease, lower transplantation rates and higher waitlist deaths. These data have significance for designing ethnicity specific interventions.

Primary Biliary Cholangitis in British Columbia First Nations: Clinical features and discovery of novel genetic susceptibility loci

BACKGROUND & AIMS

Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease characterized by destruction of intrahepatic bile ducts, portal inflammation and cirrhosis. Although rare in most populations, it is prevalent and often familial in British Columbia First Nations. We hypothesized that major genetic factors increased the risk in First Nations.

METHODS

In all, 44 individuals with Primary Biliary Cholangitis and 61 unaffected relatives from 32 First Nations families participated. Family history and co-morbidities were documented. Medical records were reviewed and available biopsies were re-reviewed by our team pathologist. Genotyping was performed on DNA from 36 affected persons and 27 unaffected relatives using the Affymetrix Human Mapping 500K Array Set. MERLIN software was used to carry out multipoint parametric and nonparametric linkage analysis. Candidate genes were identified and entered into InnateDB and KEGG software to identify potential pathways affecting pathogenesis.

RESULTS

In all, 34% of families were multiplex. Fifty per cent of cases and 33% of unaffected relatives reported other autoimmune disease. Three genomic regions (9q21, 17p13 and 19p13) produced LOD scores of 2.3 or greater suggestive of linkage, but no single linkage peak reached statistical significance. Candidate genes identified in the three regions suggested involvement of IL17, NFκB, IL6, JAK-STAT, IFNγ and TGFβ immune signalling pathways. Specifically, four genes-ACT1, PIN1, DNMT1 and NTN1-emerged as having roles in these pathways that may influence Primary Biliary Cholangitis pathogenesis.

CONCLUSIONS

Our whole genome linkage study results reflect the multifactorial nature of Primary Biliary Cholangitis, support previous studies suggesting signalling pathway involvement and identify new candidate genes for consideration.

Celiac disease in native Indians from Brazil: A clinical and epidemiological survey

Background:

Celiac disease has been described in populations from around the world, with recent data emphasizing the occurrence of the disease in ethnic minorities. There are only a few studies evaluating celiac disease in native Indians.

Aims:

This study aimed to screen the anti-endomysial antibody (IgA-EmA) in Kaingang and Guarani Indians from southern Brazil, in order to establish a clinical serological evaluation of celiac disease in these individuals.

Material and Methods:

Serum samples from 321 individuals (125 male and 196 female; 4-86 years old) from Mangueirinha Indigenous Reserve, State of Parana, Brazil, and 180 non-Indigenous healthy individuals (62 male and 118 female; 2-81 years old) were analysed to the presence of anti-endomysial antibody class IgA by indirect immunofluorescence assay. Amongst the Indians, 158 were Kaingang, 98 Guarani and 65 of mixed race. Indians presenting complaints of diarrhea (N=12) were also evaluated to the IgG class of anti-endomisyal antibody.

Results:

None of the individuals showed positive results either to IgA or IgG anti-endomysial antibodies.

Conclusions:

Although the results indicate an absence of celiac disease in Kaingang and Guarani Indians, the authors call attention to the importance of following up indigenous children or adults presenting gastrointestinal complaints or other symptoms related to the disease. Consideration should be given to the genetic background of these individuals, allied to the inter ethnic marriages and the changing habits or occupational activities, that have gradually introduced diseases previously not described in indigenous populations.

Liver transplant outcomes in a Canadian First Nations population

BACKGROUND

A higher incidence of autoimmune disorders may predispose First Nations (FN) individuals to higher rates and more severe episodes of rejection, graft loss and mortality following liver transplantation for advanced liver disease.

METHODS

A retrospective review of patient outcomes in a single centre providing long-term follow-up care for FN and non-FN patients transplanted for advanced liver disease was conducted.

RESULTS

A total of 20 FN and 129 non-FN charts were available for review. FN subjects were younger at transplantation (mean [± SD] age 32.4±4.1 years versus 46.3±1.4 years; P=0.00005), less often male (35% versus 58%; P=0.05), more commonly transplanted for autoimmune hepatitis (30% versus 4.7%; P=0.006), less often from urban residences (25% versus 74%; P=0.0001) and less compliant with medical care (20% versus 80%; P=0.007). After a mean follow-up period of 11.0±1.5 years and 8.4±0.5 years in FN and non-FN subjects, respectively, the incidence and severity of rejection, graft and patient survival were similar between cohorts.

CONCLUSION

Although demographic profiles, nature of the underlying disease and compliance differed, the rates and severity of rejection, graft and patient survival were similar in FN and non-FN patients who underwent liver transplantation for advanced liver disease.

Autoimmune hepatitis in a North American Aboriginal/First Nations population

North American Aboriginal populations are at increased risk for developing immune-mediated disorders, including autoimmune hepatitis. In the present study, the demographic, clinical, biochemical, serological, radiological and histological features of autoimmune hepatitis were compared in 33 First Nations (FN) and 150 predominantly Caucasian, non-FN patients referred to an urban tertiary care centre. FN patients were more often female (91% versus 71%; P=0.04), and more likely to have low serum albumin (69% versus 36%; P=0.0006) and elevated bilirubin (57% versus 35%; P=0.01) levels on presentation compared with non-FN patients. They also had lower hemoglobin, and complement levels, more cholestasis and higher serum immunoglobulin A levels than non-FN patients (P=0.05 respectively). Higher histological grades of inflammation and stages of fibrosis, and more clinical and radiological evidence of advanced liver disease were observed in FN patients, but the differences failed to reach statistical significance. The results of the present study suggest that in addition to being more common, autoimmune hepatitis may be more severe in FN populations, compared with predominantly Caucasian, non-FN populations.

Chronic liver disease in Aboriginal North Americans

A structured literature review was performed to detail the frequency and etiology of chronic liver disease (CLD) in Aboriginal North Americans. CLD affects Aboriginal North Americans disproportionately and is now one of the most common causes of death. Alcoholic liver disease is the leading etiology of CLD, but viral hepatitis, particularly hepatitis C, is an important and growing cause of CLD. High rates of autoimmune hepatitis and primary biliary cirrhosis (PBC) are reported in regions of coastal British Columbia and southeastern Alaska. Non-alcoholic liver disease is a common, but understudied, cause of CLD. Future research should monitor the incidence and etiology of CLD and should be geographically inclusive. In addition, more research is needed on the treatment of hepatitis C virus (HCV) infection and non-alcoholic fatty liver disease (NAFLD) in this population.

Retrospective review of pediatric and adult autoimmune hepatitis in two quaternary care centres in British Columbia: increased prevalence seen in British Columbia's First Nations community

BACKGROUND

It has been previously reported that British Columbia's (BC's) First Nations (Aboriginal) community has an increased risk of autoimmune diseases, including rheumatological conditions (rheumatoid arthritis, systemic lupus) and primary biliary cirrhosis. The researchers hypothesized that this community may also be at increased risk for autoimmune hepatitis (AIH).

METHODS

Independent, retrospective reviews of the databases of two separate tertiary/quaternary British Columbia university-affiliated health care institutions, the Adult Liver Transplant Program of the BC Transplant Society and the Division of Pediatric Gastroenterology, BC Children's Hospital (Vancouver, BC), were performed. All patients referred with a diagnosis of probable or definite AIH who identified themselves as being of First Nations descent from 1988 to 2004 were reviewed. The liver transplant database records all adult patients in the province referred for transplant assessment. The pediatric database records all children referred to the BC Children's Hospital.

RESULTS

A total of 68 adult patients with a definite or probable diagnosis of AIH were referred to the liver transplant program. Twelve patients (17.6%) were Aboriginal, 11 of which were female. Similarly, a total of 30 children with probable or definite AIH were identified from the pediatric database. Six of these cases (20%) were identified in Aboriginal children.

CONCLUSIONS

The findings suggest an increased prevalence of AIH among BC's First Nations community. A disproportionate First Nations representation was found on independent review of two databases. Future studies are needed to determine the true prevalence of AIH in this community, and to uncover the genetic predisposition and the environmental triggers explaining this phenomenon.

DNA on loan: issues to consider when carrying out genetic research with aboriginal families and communities

In the current research milieu where genetic etiology is considered a critical component in the discovery of pathogenesis, aboriginal families and communities affected with genetic conditions may be considered as research participants. However, because of concerns about the impact of genetic information and historical harmful research practices, some aboriginal communities have considerable unease when faced with this prospect. Therefore, in the circumstance that genetics is considered an important part of research inquiry by aboriginal families and communities, there needs to be assurance that the research will be carried out according to mutual expectations. A research relationship that respects aboriginal individuals and communities within their culture and is in keeping with their values is essential. This respect extends to the use of biological samples, considering the DNA to be 'on loan' to the researcher for the purpose of the research for which consent was obtained. This paper will explore practical ways of maintaining a respectful research relationship when genetics research with aboriginal people is undertaken.

Autoimmune liver disease and the Canadian First Nations Aboriginal Communities of British Columbia’s Pacific Northwest

Primary biliary cirrhosis (PBC) is a well-known but uncommon chronic liver disease that is presumed to be of autoimmune etiology. Recently, investigations in British Columbia (BC), a province of Canada situated along the Pacific North-West of North America, have suggested that PBC is not a rare disease amongst BC’s Aboriginal (i.e. First Nations) communities. Geographically, BC is adjacent to South East Alaska, an American state that has also reported an increased prevalence of PBC amongst its Aboriginal communities. In this article, the medical evidence supporting a hypothesis of increased risk of PBC amongst BC’s First Nations communities is reviewed. Evidence suggesting that autoimmune hepatitis is also more likely amongst BC’s First Nations communities is also presented.

Surgical Morbidity and Mortality among American Indian and Alaska Native Veterans: A Comparative Analysis

BACKGROUND

Few studies have examined surgical risk factors and outcomes in American Indians and Alaska Natives (AI/ANs). My colleagues and I sought to determine if prevalence of preoperative risk factors for morbidity and mortality differed between male AI/AN and Caucasian surgical patients, and to determine if AI/ANs had an increased risk of surgical morbidity or mortality.

STUDY DESIGN

We obtained data from the Veterans Affairs National Surgical Quality Improvement Program on major, noncardiac, surgical procedures performed between 1991 and 2002 for all AI/AN men (n = 2,155) and a random sample of Caucasian men (n = 2,264), matched by facility. Chi-square and t-test analyses were used to assess differences in preoperative risk factors between the two groups. Logistic regression was used to determine whether AI/AN race was independently associated with 30-day morbidity (defined as 1 or more of 21 postoperative complications) or 30-day all cause mortality after adjustment for major risk factors.

RESULTS

Prevalence of major preoperative risk factors for morbidity and mortality often differed between the groups. Compared with Caucasians, AI/AN race did not predict morbidity (adjusted odds ratio, 0.92; 95% CI, 0.75-1.13), but AI/ANs were at higher risk for 30-day all cause postoperative mortality (adjusted odds ratio, 1.56; 95% CI, 1.04-2.35).

CONCLUSIONS

Our results add postoperative mortality to health disparities experienced by AI/ANs. Future research should be conducted to identify other factors that contribute to this disparity.