Prevalence of gastric parietal cell antibodies and intrinsic factor antibodies in primary biliary cirrhosis

Variant and Specific Forms of Autoimmune Cholestatic Liver Diseases

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are the main autoimmune cholestatic liver diseases. IgG4-associated sclerosing cholangitis is another distinct immune-mediated cholestatic disorder of unknown aetiology that is frequently associated with autoimmune pancreatitis or other IgG4-related diseases. Although the majority of PBC and PSC patients have a typical presentation, there are common and uncommon important variants or specific subgroups that observed in everyday routine clinical practice. In this updated review, we summarize the published data giving also our own experience on the variants and specific groups of autoimmune cholestatic liver diseases. Actually, we give in detail the underlining difficulties and the rising dilemmas concerning the diagnosis and management of these special conditions in the clinical spectrum of autoimmune cholestatic liver diseases including the IgG4-associated sclerosing cholangitis highlighting also the uncertainties and the potential new eras of the research agenda.

Pernicious anemia associated with cryptogenic cirrhosis: Two case reports and a literature review

RATIONALE

Pernicious anemia (PA) is an autoimmune gastritis that results from the destruction of gastric parietal cells and the associated lack of an intrinsic factor to bind ingested vitamin B12. While an association between PA and various liver diseases has been rarely reported, reports of associated diseases include primary biliary cholangitis, autoimmune hepatitis, and Interferon-treated hepatitis C. We present 2 cases of PA associated with cryptogenic cirrhosis (CC), which has not been previously reported in the literature.

PATIENT CONCERNS

A 42-year-old man presented with fatigue, pallor, and sustained abdominal distension that had persisted for 15 days. An 87-year-old man was admitted to the hospital for an unsteady gait and loss of appetite that had persisted for 20 days.

DIAGNOSES

Symptoms, laboratory tests, and imaging findings for both patients were indicative of PA and CC.Both had neurological and psychiatric symptoms during hospitalization that were ultimately linked to a vitamin B12 deficiency but not hepatic encephalopathy.

INTERVENTIONS

Both patients received intramuscular injections of vitamin B12.

OUTCOMES

Hemoglobin levels of the 2 patients increased gradually, and their neurological symptoms were alleviated.

LESSONS

PA associated with a liver disease is rare, and the underlying mechanism can only now be clarified. We speculate that autoimmune dysfunction and chronic vitamin B12 deficiency caused by PA might be unique causes of liver cirrhosis. Additional investigations are needed to verify these findings.

Estimate of the Prevalence of Anti-Gastric Parietal Cell Autoantibodies in Healthy Individuals Is Method Dependent

OBJECTIVES

Anti-parietal cell antibodies (APCA) are a serologic marker of autoimmune gastritis. Their prevalence in healthy individuals is not well defined.

METHODS

We evaluated APCA prevalence in 515 healthy blood-donors by rat/primate tissue indirect immunofluorescence (IIF), enzyme-linked immunosorbent assay (ELISA), and immunoblot.

RESULTS

Fifty-three of 515 (10.3%) subjects were positive for APCA by at least one method: 18 only by ELISA, 10 by rodent tissue IIF, and one by primate tissue IIF; 18 were positive by ELISA and primate tissue IIF, and one by ELISA and rodent tissue IIF. Two were positive by both IIF methods, and three were triple positive. APCA positivity was confirmed by immunoblot in 100% of ELISA positive, in 95.8% of positive primate tissue IIF, and in 50% of positive rat tissue IIF.

CONCLUSIONS

A great discrepancy in APCA prevalence detected by different methods in this cohort was apparent. Thus, the results on APCA prevalence in healthy individuals are likely method-dependent.

Antimitochondrial Antibody-Negative Primary Biliary Cholangitis: Is It Really the Same Disease?

Antimitochondrial antibody (AMA)-negative primary biliary cholangitis (PBC) is a term reserved for patients with clinical and histopathological findings consistent with PBC but without positive AMA. There does not seem to be a natural progression from AMA negativity to positivity. Antinuclear and antismooth muscle antibodies are frequently found in the absence of histologic autoimmune hepatitis features. The disease course may be more severe than AMA-positive. Response to standard therapy for PBC and autoimmune hepatitis varies. Nevertheless, there is insufficient evidence to suggest AMA-negative PBC is different enough to warrant classification as a separate disease from AMA-positive PBC.

Increased cholestatic enzymes in two patients with long-term history of ulcerative colitis: consider primary biliary cholangitis not always primary sclerosing cholangitis

Several hepatobiliary disorders have been reported in ulcerative colitis (UC) patients with primary sclerosing cholangitis (PSC) being the most specific. Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, rarely occurs in UC. We present two PBC cases of 67 and 71 years who suffered from long-standing UC. Both patients were asymptomatic but they had increased cholestatic enzymes and high titres of antimitochondrial antibodies (AMA)-the laboratory hallmark of PBC. After careful exclusion of other causes of cholestasis by MRI/magnetic resonance cholangiopancreatography (MRCP), virological and microbiological investigations, a diagnosis of PBC associated with UC was established. The patients started ursodeoxycholic acid (13 mg/kg/day) with complete response. During follow-up, both patients remained asymptomatic with normal blood biochemistry. Although PSC is the most common hepatobiliary manifestation among patients with UC, physicians must keep also PBC in mind in those with unexplained cholestasis and repeatedly normal MRCP. In these cases, a reliable AMA testing can help for an accurate diagnosis.

Autoantibodies other than Anti-desmogleins in Pemphigus Vulgaris Patients

Background:

Pemphigus vulgaris (PV) is an immunoglobulin G-mediated autoimmune bullous skin disease. Nonorgan-specific antibodies were detected in Tunisian and Brazilian pemphigus patients with different prevalence.

Materials and Methods:

Fifty PV patients and fifty controls were screened for antinuclear antibodies (ANAs), anti-smooth muscle antibodies (ASMAs), anti-parietal antibodies (APAs), anti-mitochondrial antibodies, and Anti-nuclear cytoplasmic antibodies (ANCA) by indirect immunofluorescence.

Results:

Thirty-nine patients were female and 11 were male. Fifteen patients did not receive treatment before while 35 patients were on systemic steroid treatment ± azathioprine. Twenty (40%) of the PV patients and 1 (2%) control had positive ANA. ANA was significantly higher in PV patients than controls, P < 0.0001. ASMAs were detected in 20 (40%) PV patients and none of the controls. ASMA was significantly higher in PV patients than controls, P < 0.0001. No significant difference was detected between treated and untreated regarding ANA, P - 0.11. However, there was a significant difference between treated and untreated regarding ASMA, P - 0.03. Six patients (12%) and none of the controls had positive APA. There was a significant difference between the patients and the controls in APA. P - 0.027.

Conclusion:

Egyptian PV patients showed more prevalent ANA, ASMA, and APA than normal controls. Follow-up of those patients is essential to detect the early development of concomitant autoimmune disease. Environmental factors might account for the variability of the nonorgan-specific antibodies among different populations.

Low level autoantibodies can be frequently detected in the general Australian population

The aim of this study was to determine the prevalence and type of autoantibodies in a general Australian population cohort. Samples collected from 198 individuals included in a cross sectional Busselton Health Study were tested using autoantibody assays routinely performed at Clinical Immunology, PathWest Laboratory Medicine, Western Australia. At least one autoantibody was detected in 51.5% of individuals (males = 45.1%, females = 58.3%). The most frequently detected serum autoantibodies were anti-beta-2-glycoprotein I (12.1%) followed by anti-smooth muscle (11.6%) and anti-thyroid peroxidase (8.6%). Vasculitis associated anti-neutrophil cytoplasmic antibodies were present in 5.1%, while anti-nuclear antibodies were detected in 8.6% of individuals. Notably, 65% of positive results were detected at low levels with the exception of anti-myeloperoxidase and anti-beta 2 glycoprotein I IgG antibodies. Autoantibodies are commonly detected at low levels in a predominantly Australian or European population cohort. No large Australian study has yet provided these data for contemporary routine tests. This paper gives important information on the background frequency of autoantibodies in the general population. Due to the nature of this study we are unaware of whether these individuals have subsequently developed an autoimmune disease, however this was not clinically diagnosed at the time of sample collection.

Polyautoimmunity in autoimmune gastritis

OBJECTIVES

Autoimmune gastritis may be associated with other organ-specific autoimmune disorders, but the prevalence of this association is not entirely quantified. The aims of this study were to investigate the prevalence of autoimmune disorders and evaluate the factors that might affect this association in patients with autoimmune gastritis.

METHODS

A total of 320 patients with autoimmune gastritis were retrospectively studied and data on concomitant autoimmune diseases, serum gastrin and chromogranin A levels, anti-Hp IgG, antiparietal cell antibodies, presence of enterochromaffin-like cell hyperplasia and gastric atrophy were gathered for each patient and associations between autoimmune gastritis and studied parameters were explored through descriptive statistics and logistic regression analysis.

RESULTS

Of the 320 atrophic body autoimmune gastritis patients, 171 (53.4%) had an associated autoimmune disorder. Autoimmune thyroiditis was the most common concurrent disease, diagnosed in 116 patients (36.2%). Multivariate analysis showed that, presence of enterochromaffin cell hyperplasia (odds ratio [OR] 9.445, 95% confidence [CI]: 4.42-20.22), serum gastrin (OR 3.1, 95% CI: 1.46-6.60) and serum chromogranin A (OR 4.14, 95% CI: 2.01-8.52) levels remained significantly associated with the coexistence of an autoimmune disease.

CONCLUSIONS

Concurrent autoimmune diseases are common in patients with autoimmune gastritis. Autoimmune thyroiditis is the most encountered disease. These data suggest that patients with autoimmune gastritis should be investigated for the presence of an autoimmune disease, in particular patients with enterochromaffin cell hyperplasia and those with serum gastrin and chromogranin A levels above cut-off values.

Clinical significance of the fluctuation of primary biliary cirrhosis-related autoantibodies during the course of the disease

Primary biliary cirrhosis (PBC) is a chronic cholestatic disease characterized by the presence of antimitochondrial antibodies (AMA). PBC-specific antinuclear antibodies (ANA) have been characterized and associated with disease progression and outcome. We evaluated the clinical significance of the presence and serial changes in titers of AMA, PBC-specific ANA (anti-gp210, anti-sp100) and anti-chromatin antibodies. Over a median (IQR) period of 35 (36) months, 512 specimens were collected from 110 patients. Autoantibodies were detected by commercial ELISAs (INOVA Diagnostics). Biochemical, clinical, and histological status were included at initial presentation and during follow-up visits. The Mayo risk score was calculated as a prognostic index at each time point. Liver biopsy findings were classified according to Ludwig's classification and biochemical response to ursodeoxycholic acid was evaluated according to Pares. At baseline, AMA IgG and IgA, anti-gp210 IgG, anti-sp100 IgG and anti-chromatin IgG were detected in 92/110 (83.6%), 57/110 (51.8%), 5/110 (4.5%), 14/110 (12.7%), and 0/110 (0%) patients, respectively. Positivity for all autoantibodies apart from anti-chromatin, at baseline visit (n = 110 patients), in all tested sera (n = 512) as well as increased autoantibodies titers during follow-up were associated with biochemically and/or histologically advanced disease. A decrease of anti-sp100 titers but not of anti-gp210 titers during follow-up was associated with improvement of Mayo risk score (p = 0.025) and response to ursodeoxycholic acid (p = 0.016). These results suggest that detection of AMA and PBC-specific ANA was correlated with disease severity. Serial changes of anti-sp100 titers and not of anti-gp210 titers might prove useful for monitoring the disease course and treatment outcome.

Potential Roles for Infectious Agents in the Pathophysiology of Primary Biliary Cirrhosis: What's New?

Primary biliary cirrhosis (PBC) is a progressive cholestatic liver disease serologically characterized by the presence of high-titer antimitochondrial antibodies and, histologically by chronic nonsuppurative cholangitis and granulomata. The aetiology of the disease remains elusive, although genetic, epigenetic, environmental, and infectious factors have been considered important for the induction of the disease in genetically prone individuals. The disease shows a striking female predominance and becomes clinically overt at the fourth to sixth decade. These characteristics have prompted investigators to consider infections that predominate in women at these ages as the likely candidates for triggering the disease. Recurrent urinary tract infections due to Escherichia coli were the first infections to be considered pathogenetically relevant. Over the years, several other microorganisms have been linked to the pathogenesis of PBC owing to epidemiological, immunological, microbiological, or experimental findings in animal models. Recent studies have provided data supporting the pathogenic role of Novosphingobium aromaticivorans and betaretroviruses. Several reports have linked other organisms to the induction of the disease and/or the maintenance of the auto-aggressive responses that are perpetuated over the course of the disease. This review highlights the findings of the most recent studies investigating the link between infections and PBC. We also discuss the close interplay of the infectious agents with other environmental and genetic factors, which may explain the multifaceted nature of this puzzling disease.

Rheumatoid arthritis and primary biliary cirrhosis: cause, consequence, or coincidence?

Primary biliary cirrhosis (PBC) is a progressive cholestatic liver disease characterized serologically by cholestasis and the presence of high-titre antimitochondrial antibodies and histologically by chronic nonsuppurative cholangitis and granulomata. PBC patients often have concomitant autoimmune diseases, including arthropathies. This raises the question as to whether there are shared features in the pathogenesis of those diseases with the pathogenesis of PBC. Epidemiological and large case studies have indicated that although the incidence of rheumatoid arthritis (RA) is not significantly raised in PBC patients, there appears to be a higher rate of RA in PBC patients and their relatives. Genetic studies have demonstrated that several genes implicated in PBC have also been implicated in RA. Epigenetic studies provided a wealth of data regarding RA, but the findings on epigenetic changes in PBC are very limited. As well, certain infectious agents identified in the pathogenesis of PBC may also play a role in the pathogenesis of RA. These data suggest that although RA is not significantly present in PBC, some individuals with certain genetic traits and environmental exposures may develop both conditions. This concept may also apply to other concomitant diseases found in PBC patients.

Factors associated with parietal cell autoantibodies in the general population

The presence in serum of parietal cell autoantibodies (PCA) is a characteristic of autoimmune gastritis. We determined the prevalence of PCA in the general population and investigate their association with type 2 diabetes, insulin resistance and lifestyle factors related with autoimmune gastritis. A cross-sectional study was performed, involving 429 individuals enrolled in a cohort study of the general population of the Canary Islands. All participants underwent physical examination, provided a blood sample and responded to a questionnaire regarding health and lifestyle factors. Serum concentrations of PCA, soluble CD40 ligand (sCD40L), C-peptide and glucose (to determine insulin resistance) were measured. The association of PCA with the other factors was determined with bivariate analysis, and logistic regression models were used to adjust the associations for age and sex. The prevalence of PCA was 7.8% (95% CI=10.3-5.3). The factors associated with PCA were female sex (p=0.032), insulin resistance (p=0.016), menopause (p=0.029) and sCD40L (p=0.019). Alcohol consumption (p=0.006) and smoking (p=0.005) were associated with low prevalences of PCA. After adjustment for age and sex, the association with PCA was confirmed for smoking (OR=0.1 [0.0-0.9]), alcohol consumption (OR=0.3 [0.1-0.9]), insulin resistance (OR=2.4 [1.1-4.9]), female sex (OR=2.4 [1.1-5.3]), sCD40L (OR=3.7 [1.2-11.4]) and menopause (OR=5.3 [1.2-23.3]). In conclusion, smoking and alcohol consumption acted as protective factors against the appearance of PCA in the general population, whereas female sex, menopause, insulin resistance and elevated serum sCD40L were risk markers for PCA. In patients who smoke or drink alcohol, clinicians should be cautious when using PCA to rule out autoimmune gastritis.

Tuberculosis Is Not a Risk Factor for Primary Biliary Cirrhosis: A Review of the Literature

Primary biliary cirrhosis (PBC) is a progressive cholestatic liver disease characterised serologically by cholestasis and the presence of high-titre antimitochondrial antibodies, and histologically by chronic nonsuppurative cholangitis and granulomata. As PBC is a granulomatous disease andMycobacterium tuberculosisis the most frequent cause of granulomata, a causal relation between tuberculosis and PBC has been suggested. Attempts to find serological evidence of PBC-specific autoantibodies such as AMA have been made and, conversely, granulomatous livers from patients with PBC have been investigated for molecular evidence ofMycobacterium tuberculosis. This paper discusses in detail the reported data in support or against an association betweenMycobacterium tuberculosisinfection and PBC. We discuss the immunological and microbiological data exploring the association of PBC with exposure toMycobacterium tuberculosis. We also discuss the findings of large epidemiologic studies investigating the association of PBC with preexistent or concomitant disorders and the relevance of these findings with tuberculosis. Genome-wide association studies in patients with tuberculosis as well as in patients with PBC provide conclusive hints regarding the assumed association between exposure to this mycobacterium and the induction of PBC. Analysis of these data suggest thatMycobacterium tuberculosisis an unlikely infectious trigger of PBC.

Gastric secretion

PURPOSE OF REVIEW

This review summarizes the past year's literature regarding the regulation of gastric exocrine and endocrine secretion at the central, peripheral, and cellular levels.

RECENT FINDINGS

Gastric acid secretion is an intricate and dynamic process that is regulated by neural (efferent and afferent), hormonal (e.g., gastrin), and paracrine (e.g., histamine, ghrelin, somatostatin) pathways as well as mechanical (e.g., distension) and chemical (e.g., protein, glutamate, coffee, and ethanol) stimuli. Secretion of hydrochloric acid by the parietal cell involves recruitment and fusion of HK-adenosine triphosphatase (HK-ATPase)-containing cytoplasmic tubulovesicles with the apical membrane with subsequent electroneutral transport of hydronium ions in exchange for potassium; the source of the latter is the potassium channel, KCNQ1. Concomitantly, chloride exits via the cystic fibrosis transmembrane regulator. Inhibition of the HK-ATPase by proton pump inhibitors leads to a compensatory hypergastrinemia which, if prolonged, results in parietal and enterochromaffin-like cell hyperplasia. The clinical consequence is rebound acid secretion which may induce dyspeptic symptoms in healthy individuals and exacerbate reflux symptoms in patients with gastroesophageal reflux disease.

SUMMARY

We continue to make progress in our understanding of the regulation of gastric acid secretion in health and disease. A better understanding of the pathways and mechanisms regulating acid secretion should lead to improved management of patients with acid-induced disorders as well as those who secrete too little acid.