Antimitochondrial antibody-negative chronic nonsuppurative destructive cholangitis. Atypical primary biliary cirrhosis or autoimmune cholangitis?

Anti-mitochondrial Antibody-Negative Primary Biliary Cholangitis Is Part of the Same Spectrum of Classical Primary Biliary Cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease in which anti-mitochondrial antibodies (AMA) are the diagnostic hallmark. Whether AMA-negative PBC patients represent a different phenotype of disease is highly debated.

AIMS

The purpose of our study was to compare AMA-positive and AMA-negative PBC patients in a large non-white admixed Brazilian cohort.

METHODS

The Brazilian Cholestasis Study Group multicentre database was reviewed to assess demographics, clinical features and treatment outcomes of Brazilian PBC patients, stratifying data according to AMA status.

RESULTS

A total of 464 subjects (95.4% females, mean age 56 ± 5 years) with PBC were included. Three hundred and eighty-four (83%) subjects were AMA-positive, whereas 80 (17%) had AMA-negative PBC. Subjects with AMA-negative PBC were significantly younger (52.2 ± 14 vs. 59.6 ± 11 years, p = 0.001) and had their first symptom at an earlier age (43.2 ± 13 vs. 49.5 ± 12 years, p = 0.005). Frequency of type 2 diabetes was significantly increased in subjects with AMA-negative PBC (22.5% vs. 12.2%, p = 0.03). Lower IgM (272.2 ± 183 vs. 383.2 ± 378 mg/dL, p = 0.01) and triglycerides (107.6 ± 59.8 vs.129.3 ± 75.7 mg/dL, p = 0.025) and higher bilirubin (3.8 ± 13.5 vs. 1.8 ± 3.4 mg/dL, p = 0.02) levels were also observed in this subgroup. Response to ursodeoxycholic acid varied from 40.5 to 63.3% in AMA-positive and 34 to 62.3% in AMA-negative individuals, according to different response criteria. Outcomes such as development of liver-related complications, death and requirement for liver transplantation were similar in both groups.

CONCLUSIONS

AMA-negative PBC patients are similar to their AMA-positive counterparts with subtle differences observed in clinical and laboratory features.

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.

Practical guidelines for examination of adults with asymptomatic hypertransaminasaemia

The causes of sustained elevation of serum transaminases in asymptomatic adults, both hepatic and extrahepatic, are varied. In order to reach an aetiological diagnosis, a standardized protocol should be applied, aimed firstly at ruling out the most common causes, such as chronic hepatitis (viral or autoimmune), metabolic diseases, and toxic liver diseases. Several biochemical patterns, which take into account transaminase, cholestatic enzyme, muscle enzyme, ferritin and ceruloplasmin levels, as well protein electrophoresis and autoantibody measurement, will identify most causes. In cases in which a diagnosis cannot be reached with the use of these non-invasive methods, a needle liver biopsy will be justified.

Autoimmune liver disease - are there spectra that we do not know?

Autoimmune liver diseases (AILDs) are common leading causes for liver cirrhosis and terminal stage of liver disease. They have variable prevalence among patients with liver disease and have two major clinical and biochemical presentations. Autoimmune hepatitis (AIH) is the typical example of hepatocellular AILD, but it can also be presented under a cholestatic pattern. AIH has a scoring diagnostic system and respond in most cases to the treatment with prednisolone and azathioprine. Primary biliary cirrhosis (PBC) is the second most common AILD, with a cholestatic presentation and characterized by positive antimitochondrial antibody (AMA). It has an excellent response and long term outcome with the administration of ursodeoxycholic acid (UDCA). Another AILD that is thought to be a variant of PBC is the autoimmune cholangitis, being a disease that has biochemical and histological features similar to PBC; but the AMA is negative. Primary sclerosing cholangitis (PSC) is a rare entity of AILD that has a cholestatic presentation and respond poorly to the treatment, with the ultimate progression to advance liver cirrhosis in most patients. Other forms of AILD include the overlap syndromes (OS), which are diseases with mixed immunological and histological patterns of two AILD; the most commonly recognized one is AIH-PBC overlap (AIH-PSC overlap is less common). The treatment of OS involves the trial of UDCA and different immunosuppressants. Here we present three case reports of unusual forms of chronic liver diseases that most likely represent AILD. The first two patients had a cholestatic picture, whereas the third one had a hepatocellular picture at presentation. We discussed their biochemical, immunological and histological features as well as their response to treatment and their outcomes. Then, we compared them with other forms of AILD.

Antimitochondrial antibody-negative primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is considered a classic autoimmune disease insofar as 95% of patients are seropositive for specific antimitochondrial antibodies (AMA). Yet it is still the case that the remaining 5% of patients have equivalent disease but test persistently AMA negative. Although variations exist in the immunologic profile of these patients, clinically there are no discernable differences, and although the diagnostic threshold is higher, the treatment and prognosis mirror that of classic disease. Previous terminology, therefore, has been abandoned in favor of the description, AMA-negative PBC.

Overlap syndromes with autoimmune hepatitis in chronic cholestatic liver diseases

Conditions exhibiting features of two different autoimmune liver diseases are commonly designated overlap syndromes, although there is no current agreement on what constitutes an overlap syndrome or specific diagnostic criteria. As in the classic autoimmune liver diseases, such as autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), the etiology is unknown but presumed to be related to alterations of immune regulation. Distinction of these clinical entities is important for management as outcomes may differ from outcomes of patients with diagnosis of classic autoimmune liver diseases. Due to their presumed rarity, no large therapeutic trials are available and treatment of overlap conditions is empirical and based upon extrapolation of data from the primary autoimmune liver diseases. PBC-AIH overlap is the most frequently described overlap syndrome and may be associated with a poor prognosis. This may represent an important and unrecognized cause of resistance to ursodeoxycholic acid in patients with PBC. PSC-AIH overlap is less commonly reported. Prognosis may be better than in patients with PSC alone; however, worse than in patients with AIH alone. Further studies are needed for determining diagnosis, natural history and optimal therapeutic strategies of overlap syndromes of autoimmune liver disease.

Role of auto-antibodies for the diagnosis of chronic cholestatic liver diseases

Auto-antibodies are an integral part of the diagnostic armentarium in chronic cholestatic liver disorders, such as primary sclerosing cholangitis (PSC), primary biliary cirrhosis (PBC),auto-immune cholangitis, or overlap syndromes among these disorders. However, care should be taken not to overestimate the diagnostic specificity. Auto-antibodies to mitochondrial antigens(AMAs) with reactivity to the E2 subunit of the pyruvate dehydrogenase complex represent the hallmark antibody for the diagnosis of PBC, whereas antinuclear antibodies (ANAs)with low disease specificity are found in up to 50% of these sera. Antibodies that recognize nuclear envelope proteins exert a similarly high diagnostic specificity as AMA in PBC but occur at a rather low prevalence. The role of auto-antibodies is less well-studied for patients with PSC, but there is growing evidence that only antineutrophil cytoplasmic antibodies(ANCAs) are of relevant diagnostic significance. In contrast, auto-antibodies-particularlyAMAs-do not contribute to the diagnosis of auto-immune cholangitis, whereas ANCAs,ANAs, smooth muscle antibodies, and AMAs are of varying significance in PBC-auto-immune hepatitis (AIH) or PSC-AIH overlap syndromes. It has been widely accepted that the course of the auto-antibody serum end point titers are not suited for the clinical management of patients with chronic cholestatic liver disorders. Additionally, auto-antibodies in these disorders usually do not contribute to the immunopathogenesis of the disease.

Antimitochondrial antibody negative primary biliary cirrhosis in Japan: utilization of clinical data when patients applied to receive public financial aid

BACKGROUND

We examined patients who showed laboratory and histological evidence of primary biliary cirrhosis (PBC) in the absence of antimitochondrial antibody (AMA) to elucidate the characteristics of AMA negative PBC.

METHODS

From a total of 5,805 patients with symptomatic PBC, 2,419 cases (41.7%) were selected in the present study, who were diagnosed using the following criterion; chronic non-suppurative destructive cholangitis was histologically observed and laboratory data did not contradict PBC. The information collected from records included sex, age, symptoms, physical findings, and complicated autoimmune diseases. We then evaluated these data according to the positivity of AMA.

RESULTS

Of the total subjects, 470 cases (19.4%) were found to be negative for AMA. The proportion of female patients was higher among the AMA negative group than among the AMA positive one. Pruritus was found less frequently among patients with AMA negative PBC than among those with AMA positive PBC. Levels of alkaline phosphatase, γ-glutamyl transpeptidase, and IgM were significantly lower among patients with AMA negative PBC than among those with AMA positive PBC. Complications such as Sjögren’s syndrome, rheumatoid arthritis, and scleroderma, including CREST syndrome, were found with significantly higher frequency among patients with AMA negative PBC than among those with AMA positive PBC.

CONCLUSION

Considering serum level of IgM and frequencies of complicated autoimmune diseases, it is possible that Japanese patients with AMA negative PBC are consistent with the disease entity of autoimmune cholangitis reported in western countries.

Autoantibodies in autoimmune liver disease

Autoantibodies indicate an immune reactive state, but in liver disease they lack pathogenicity and disease specificity. Antinuclear antibodies, smooth muscle antibodies, antibodies to liver/kidney microsome type 1, antimitochondrial antibodies, and perinuclear antineutrophil cytoplasmic antibodies constitute the standard serological repertoire that should be assessed in all liver diseases of undetermined cause. Antibodies to soluble liver antigen/liver pancreas, asialoglycoprotein receptor, actin, liver cytosol type 1, nuclear antigens specific to primary biliary cirrhosis, and pore complex antigens constitute an investigational repertoire that promises to have prognostic and diagnostic value. These autoantibodies may emerge as predictors of treatment response and outcome. Antibodies to histones, doubled-stranded DNA, chromatin, and lactoferrin constitute a supplemental repertoire, and they support the immune nature of the liver disease. Final diagnoses and treatment strategies do not depend solely on serological markers. Autoantibodies are floating variables, and their behavior does not correlate closely with disease activity. There are no minimum levels of significant seropositivity, especially in children. Over-interpretation is the major pitfall in the clinical application of the serological results. New autoantibodies will emerge as the search for target antigens and key pathogenic pathways continues.

Primary biliary cirrhosis and autoimmune cholangiopathy

AMA are detected in the serum of 92% to 95% of patients with PBC using indirect immunofluorescent methods. AIC is the term used to describe the 5% to 8% of AMA-negative PBC patients who uniformly have ANA and SMA. Recent applications of more sensitive and specific tests to detect serum AMA have shown that most, if not all, patients with AIC actually do have AMA. Emerging evidence that AMA and mitochondrial autoantigens play important roles in the immunopathogenesis of NSDC also suggests that AIC and PBC are likely to be a single disease, exhibiting variation in the types of autoantibodies and in both the concentrations and immunoglobulin isotypes of AMA.

Autoimmune overlapping syndromes

The overlap syndrome raises several questions. First could these patients have two coincident autoimmune diseases? Such possibility cannot be discarded in particular in the setting of consecutive occurrence of the two conditions (eg, PBC followed by AIH) and this is consistent with the fact that autoimmune diseases are associated with one another in about 5% to 10% of cases. Furthermore, it is presumed that they share similar genetic susceptibility. A second possibility could be that overlap syndrome represents the middle of a continuous spectrum of two autoimmune liver diseases. The systematic study of the relationships between elementary histologic lesions and biochemistries in "pure" PBC patients pleads strongly for such a hypothesis. Pure PBC is characterized by 2 different groups of elementary lesions that are not interrelated: first, florid bile duct lesions and bile duct paucity and second, lymphocytic piecemeal necrosis and lobular necro-inflammatory changes. Furthermore, the first set of lesions is selectively associated with biochemical cholestasis and IgM levels, whereas the second set of lesions is selectively associated with serum transaminase activities and IgG levels. These observations are consistent with the assumption that two main mechanisms are involved in the progression of liver injury in PBC. The first is bile duct destruction leading to chronic cholestasis and fibrosis of biliary pattern. The second is lymphocytic piecemeal necrosis of hepatocytes, which tends to lead to cirrhosis, the pattern of which resembles cirrhosis following various forms of chronic active hepatitis. The author has therefore speculated that the picture of pure PBC results always forms the clinical and biochemical expression of the two main histologic lesions, and combination of these processes might explain why the spectrum of PBC varies from typical PBC to AIH or PBC overlap. A third hypothesis is that an exaggerated hepatitic response in PBC is associated with the HLA haplotype commonly seen in AIH, eg, B8, DR3, DR4. Further studies are obviously needed to confirm such an attractive hypothesis. Other possible explanation for the concurrent occurrence of features of both conditions in the same individual includes the selective modulation of HLA class 1, class 2 expression and Rantes by cholestasis itself and in particular bile acids. It is conceivable that the degree of interface and lobular inflammation in PBC and PSC may be modulated by chemokines, their receptors, and the parenchymal concentrations of individual bile acids that are all, at least in part, genetically determined.

Antimitochondrial and other autoantibodies

Primary biliary cirrhosis (PBC) is characterized by the presence of high-titer disease specific autoantibodies directed against mitochondrial antigens (AMA) of the inner mitochondrial membrane, that are members of the 2-oxo acid complex. Among numerous other autoantibodies found in PBC the focus of ongoing studies is on the PBC-specific anti-nuclear antibodies, that are of diagnostic and clinical relevance since they can be used as a 'positive tool' in the diagnosis of AMA-negative PBC while at the same time identifying a subgroup of patients with more advanced liver disease.

Characterization and clinical impact of antinuclear antibodies in primary biliary cirrhosis

OBJECTIVES

The clinical impact of antinuclear antibodies in primary biliary cirrhosis is uncertain. We analyzed in detail the antinuclear antibodies reactivity of primary biliary cirrhosis patients and correlated the fine specificities observed with clinical, biochemical, and immunologic parameters.

METHODS

A total of 96 consecutive primary biliary cirrhosis patients and 283 pathologic controls were studied. To dissect the fine antinuclear antibodies specificities we used different techniques, such as indirect immunofluorescence on cryostat tissue sections and cell culture (HEp-2 cells), counterimmunoelectrophoresis with thymus and spleen extracts, ELISA assays with recombinant Sp100 and purified gp210 and Lamin B receptor, and immunoblot with several recombinant nuclear and cytoplasmic antigens.

RESULTS

Antinuclear antibodies were detected in 53% of patients, with the following hierarchy of specificities: 27% anti-Sp100, 16% "multiple nuclear dots," 16% anti-gp210, 16% anti-centromere, 7% XR1, 6% anti-lamin B receptor, 5% anti-SS-A/Ro, 5% anti-ribonucleoprotein, 4% XR2, 2% anti-SS-B/La, 2% perinuclear antineutrophil cytoplasmic antibodies, and 1% anti-double-stranded deoxyribonucleic acid. Several patients showed multiple specificities. The "multiple nuclear dots" pattern was detected more often in antimitochondrial antibodies negative patients. In particular, primary biliary cirrhosis specific antinuclear antibodies (anti-Sp100, anti-gp210, and anti-lamin B receptor) were detected in nine of 13 antimitochondrial negative primary biliary cirrhosis cases. Anti-gp210 was more frequent in patients with more pronounced cholestasis and more impaired liver function.

CONCLUSIONS

Antinuclear antibodies reactivities are present in more than half of primary biliary cirrhosis patients and target diverse autoantigens located in distinct subnuclear structures. Anti-gp210 identifies a subgroup of primary biliary cirrhosis patients with more serious liver disease. Positivity for anti-Sp100, anti-gp210, and anti-lamin B receptor, either alone or in combination, may act as a serologic marker of antimitochondrial antibodies negative primary biliary cirrhosis.

Review article: is there an optimal therapeutic regimen for antimitochondrial antibody-negative primary biliary cirrhosis (autoimmune cholangitis)?

Testing for antimitochondrial antibodies is the most useful laboratory procedure in the diagnosis of primary biliary cirrhosis; nevertheless, 5-10% of patients with typical features of primary biliary cirrhosis do not have detectable antimitochondrial antibodies, their condition being referred to as antimitochondrial antibody-negative primary biliary cirrhosis or "autoimmune cholangitis". Uncertainty exists whether antimitochondrial antibody-positive and -negative primary biliary cirrhosis represent distinct entities. We reviewed studies that compared: (i) the clinical, laboratory and histological characteristics of antimitochondrial antibody-positive and -negative primary biliary cirrhosis; (ii) the response to treatment of both conditions; and (iii) the response of autoimmune cholangitis to ursodeoxycholic acid and immunosuppressive therapy. Antimitochondrial antibody-positive and -negative primary biliary cirrhosis were characterized by similar clinical, laboratory and histological abnormalities, clinical course and survival. Antimitochondrial antibody status did not seem to affect the response to ursodeoxycholic acid. At present, the efficacy of therapies for autoimmune cholangitis has not been established in controlled trials. Of 52 patients with autoimmune cholangitis treated with ursodeoxycholic acid in 13 uncontrolled studies, 83% had serum biochemical improvement. Also, a favourable effect of immunosuppressive drugs occurred in 57% of 54 patients with autoimmune cholangitis in 17 uncontrolled studies. Each of these trials included very few patients and most evaluated the effects of treatment on surrogate markers of disease only. No marker that consistently distinguished patients who would respond favourably to ursodeoxycholic acid or immunosuppression was apparent. Consequently, treatment is, at present, empirical. However, ursodeoxycholic acid may be given when histology reveals bile duct lesions, whereas immunosuppressive therapy should probably be reserved for patients exhibiting interface hepatitis.

Prevalence of autoimmune liver disease in Alaska Natives

OBJECTIVE

There is limited information on the prevalence of autoimmune liver disease in nonwhite populations. We conducted a population-based study on the prevalence of autoimmune liver diseases in Alaska natives.

METHODS

Clinical records from 1984 to July, 2000 were reviewed to identify Alaska natives with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis, autoimmune cholangitis, and overlap syndromes of two of the above. AIH was defined as definite or probable, based on criteria established by the International Autoimmune Hepatitis Group. The diagnosis of PBC was based on a positive antimitochondrial antibody of > or = 1: 40, biochemical evidence of cholestasis, and compatible liver biopsy. Autoimmune cholangitis was defined as PBC but without a positive antimitochondrial antibody. Primary sclerosing cholangitis was diagnosed on the basis of cholangiogram.

RESULTS

Seventy-seven patients with possible autoimmune liver disease were identified. Of these, 42 had definite and seven probable AIH. At presentation, 34.7% of patients with AIH presented with acute icteric hepatitis, and 65.3% were asymptomatic. Persons presenting with mild or no symptoms were more likely to have moderate to severe fibrosis on liver biopsy than those presenting with jaundice. Eighteen persons were diagnosed with PBC, five with autoimmune cholangitis, five with overlap syndrome, and none with primary sclerosing cholangitis. The combined point prevalence of AIH Alaska natives was 42.9/100,000 (95% CI = 31-57.7). The prevalence of PBC was 16/100,000 (95% CI = 12.9-25.4).

CONCLUSIONS

This population-based study demonstrates that the prevalence rates of AIH and PBC in Alaska natives are comparable with reported rates in other populations.

The role of histologic evaluation in the diagnosis and management of autoimmune hepatitis and its variants

The diagnosis of autoimmune hepatitis requires a constellation of clinical, laboratory, and histologic features that exclude other conditions and support the syndrome. Interface hepatitis is the histologic hallmark of the disease, and it may be associated with panacinar hepatitis with or without bridging necrosis or multiacinar necrosis. The liver tissue examination at accession supports the diagnosis and assesses disease severity. It can also suggest the diagnosis in patients with atypical presentations, including those with an acute onset or cryptogenic disease. The liver tissue examination during therapy defines end points of treatment (remission) and evaluates unexpected outcomes (treatment failure, incomplete response). Manifestations of bile duct injury are incompatible with the classic diagnosis of autoimmune hepatitis, and they may be coincidental findings of no or uncertain clinical significance or weak expressions of a variant form. Histologic features of autoimmune hepatitis may intermix with those of PBC, PSC, and chronic hepatitis C infection, or they may occur in autoimmune cholangitis or cryptogenic chronic hepatitis. Conditions in which the histologic findings suggest the overlap of two disorders or are insufficient for designation as classic disease constitute the variant syndromes.

Autoimmune hepatitis associated with bile duct injury resembling chronic non-suppurative destructive cholangitis

Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are representative autoimmune liver diseases in which hepatocytes and intrahepatic bile ducts, respectively, are selectively damaged by autoimmune mechanisms. Bile duct injury and loss is characteristic of PBC and chronic non-suppurative destructive cholangitis (CNSDC), in particular, is a histological hallmark of PBC. In this report, we present an unusual case of AIH accompanied by CNSDC-like bile duct injury in a 46-year-old woman. The patient's serum aminotransferase level was abnormally high. The serum levels of alkaline phosphatase, gamma-GTP and IgG were also elevated, but the IgM level was within normal limits. The titer of antismooth muscle antibody (SMA) was 1:80, while antinuclear autoantibody (ANA) and the M2 fraction of antimitochondrial antibody (AMA) were both negative. Liver biopsy disclosed CNSDC-like bile duct injuries and severe interface hepatitis and lobular hepatitis with perivenular zonal necrosis were observed. The aggregate score of the International Autoimmune Hepatitis Group corresponded to the category of probable AIH. Immunohistochemically, histocompatibility leukocyte antigen-DR, which is aberrantly expressed in the damaged bile ducts of PBC, was not found in the injured bile ducts of this case. Laboratory data were much improved by treatment with prednisone, but ursodeoxycholic acid was not effective. Although the possibility of an overlapping syndrome of AIH- and AMA-negative PBC could not be excluded, this case was diagnosed as AIH with CNSDC-like bile duct lesions.

Autoimmune cholangitis

Autoimmune cholangitis is the term that has been used to describe patients who have the clinical, biochemical, and histologic characteristics of primary biliary cirrhosis (PBC), but who are antinuclear antibody positive rather than anti-mitochondrial antibody (AMA) positive in their sera. The course of their disease is similar to AMA positive cases, and the associated nonhepatic autoimmune diseases are the same in both AMA-positive and AMA-negative PBC. Serial testing for AMA using highly sensitive and specific techniques over time suggests that in subjects with autoimmune cholangitis, their AMA negative status remains negative. The beneficial response to treatment with ursodeoxycholic acid is the same as for AMA-positive PBC. It may be preferable to use the term autoimmune cholangitis, further stratified by AMA status, instead of the somewhat innapropriate term primary biliary cirrhosis.

Clinicopathological study of primary biliary cirrhosis negative for antimitochondrial antibodies

Primary biliary cirrhosis (PBC) is characterized by the occurrence of antimitochondrial antibodies (AMA) and the progressive destruction of intrahepatic bile ducts, followed by biliary cirrhosis. However, there are about 5% of PBC patients who show clinicopathological features of PBC but are negative for AMA. In this study, clinicopathological features, as well as antibody reactivity against recombinant (r)-mitochondrial polypeptides, were examined in 30 AMA negative PBC patients and 38 AMA positive PBC patients, in whom the presence of AMA had been determined by indirect immunofluorescence (IF). There were few differences in the clinical and serological features between both groups. Histopathologic features, including staging, bile duct lesions and granuloma, were also similar in both groups. Among the 30 IF-tested AMA negative patients, 29 were also negative against beef heart mitochondrial proteins, but 24 reacted to one or more of the following r-polypeptides, as determined by immunoblotting: E1 alpha of pyruvate dehydrogenase complex, the E2 subunit of pyruvate dehydrogenase complex, and the branched-chain 2-oxo-acid dehydrogenase complex. The remaining six AMA-negative patients were asymptomatic, and histologically resembled having stage 1 of the disease, with relatively mild lymphocytic piecemeal necrosis. One case was positive for anti-smooth muscle antibody. The other clinicopathological features of these patients were similar to those of other AMA negative patients. The present study found that a majority of the AMA-negative patients fulfilling other clinicopathological criteria of PBC, had features similar to the AMA-positive PBC patients, and that a majority of IF AMA-negative patients were positive for r-polypeptides of the 2-oxo-acid dehydrogenase complex. It seems that nearly all the AMA negative patients possess a broad spectrum of antibody profile of AMA, in addition to clinicopathological and serological features.