Serum immunological profile in patients with chronic autoimmune cholestasis

Diagnostic value of anti-mitochondrial antibody in patients with primary biliary cholangitis: A systemic review and meta-analysis

BACKGROUND

Anti-mitochondrial antibodies (AMA) and the M2 subtype are considered serological hallmarks in the diagnosis of primary biliary cholangitis (PBC). However, these autoantibodies may be undetectable in some patients. This meta-analysis aimed to evaluate the diagnostic accuracy of serum AMA and M2 for PBC.

METHODS

We systematically searched PubMed, Embase, Web of Science, and the Cochrane Library for relevant studies. Pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) were calculated using a random-effects model. We also constructed hierarchical summary receiver operating characteristic curves and calculated the area under the curve values.

RESULTS

Our meta-analysis included 28 studies, of which 24 examined the diagnostic accuracy of AMA for PBC. Pooled sensitivity and specificity of AMA were 84% (95% confidence intervals [CI] 77-90%) and 98% (96-99%), respectively. Pooled LR+, LR-, and DOR were 42.2 (22.1-80.5), 0.16 (0.11-0.24), and 262 (114-601), respectively. Sixteen studies explored the diagnostic value of the M2 subtype, demonstrating pooled sensitivity and specificity of 89% (81-94%) and 96% (93-98%), respectively. Pooled LR+, LR-, and DOR were 20.3 (8.0-51.1), 0.12 (0.05-0.26), and 169 (41-706), respectively. The hierarchical summary receiver operating characteristic curves for both of serum AMA and M2 subtype lie closer to the upper left corner of the plot with area under the curve values of 0.98 (95% CI = 0.96-0.99) and 0.98 (95% CI = 0.96-0.99) respectively.

CONCLUSION

This meta-analysis provides evidence affirming the utility of AMA and M2 as sensitive and specific serological hallmarks that can facilitate early screening and diagnosis of PBC.

Looking for a new name for non-alcoholic fatty liver disease in Spanish: esteatosis hepática metabólica (EHmet)

The name of a disease does not follow any defined protocol and the scientific community's acceptance of several variants based on the customs of every location is usual. There are examples of prevalent entities with curious naming processes, such as diabetes mellitus. The first word, "diabetes", comes from the Greek dia (through), be (to go), and tes (factor), while the second word, "mellitus", comes from Latin melli (honey). As a consequence, diabetes mellitus literally means "the sweet factor that goes through…", pertaining to an excessive and sweet diuresis. Thus, we could deduce that a definition representing exactly the pathophysiology of the particular disease is not required.

Potential Involvement of Salmonella Infection in Autoimmunity

In this work, we investigated the potential effects of nontyphoidal Salmonella infection on autoantibody (AA) formation. The titer and profiles of autoantibodies in the sera of patients with acute salmonellosis due to Salmonella enterica serovar Typhimurium (S. Typhimurium) or Salmonella enterica serovar Enteritidis (S. Enteritidis) infection, as well as in convalescent patients, were determined with indirect immunofluorescence. A significant increase of autoantibodies in acute diseases caused by both serotypes of Salmonella and during post infection by S. Enteritidis was detected. Antibody profile analysis by multivariate statistics revealed that this increase was non-specific and was not dependent on the infectious agent or disease stage. The results obtained suggest that nontyphoidal Salmonella infection contributes to the generation of autoantibodies and may play a role in autoimmune disease.

Detection of anti-SP100 antibodies in primary biliary cirrhosis. Comparison of ELISA and immunofluorescence

Primary biliary cirrhosis (PBC) is, which a chronic, autoimmune liver disease. Some patients have antinuclear antibodies anti-Sp100, which are considered to be disease-specific. We compared an enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) for detection of anti-Sp100. The sensitivity of anti-Sp100 determined by ELISA and IIF was 44% and 34%, respectively. Specificity was 99% for ELISA and 98% for IIF, respectively. The positive and negative predictive value (PPV, NPV) for anti-Sp100 determined by ELISA were 98%, 60% and 95%, 56% for IIF respectively. IIF required substantial experience in interpreting subjective patterns, whereas ELISA was more sensitive, cheaper, less time consuming, and produced clear-cut quantitative results.

Diagnostic and clinical utility of antibodies against the nuclear body promyelocytic leukaemia and Sp100 antigens in patients with primary biliary cirrhosis

BACKGROUND

The lack of an immunoassay that detects antibodies to promyelocytic leukaemia (PML) protein, the primary biliary cirrhosis (PBC)-specific multiple nuclear dot (MND) antigen, has prompted us to develop a line immunoassay (LIA) for the simultaneous detection of PML and Sp100 MND-specific autoantibodies.

METHODS

PML and Sp100 were expressed in Escherichia coli, and analysed by SDS-PAGE and immunoblotting using a monoclonal antibody and MALDI-ToF fingerprinting. A quantitative PML and Sp100 LIA were developed and testing was performed in 150 anti-mitochondrial antibody (AMA) positive, 20 AMA-PBCs and 130 controls.

RESULTS

Thirty-five (23%) of 150 AMA+ PBCs (18 anti-MND+) were anti-PML+ (12%) or anti-Sp100+ (20%), 10 being anti-PML+/Sp100+, 5 single anti-PML+ and 20 single anti-Sp100+. Six (30%, 5 anti-MND+) AMA-PBCs were anti-PML+ or Sp100+. Only 2 (1.7%) pathological controls were anti-PML+ and/or anti-Sp100+. Levels of anti-PML correlated with those of anti-Sp100 (R=0.64, p<0.0001). The autoantibody profile largely remained unchanged over a 10year-follow up (52 patients, 352 samples). Anti-PML, Sp100 or MND-reactive PBCs were younger and had longer disease duration than the seronegative (p=0.06, for both). Anti-Sp100 levels correlated with the Mayo risk score (r=0.63, p=0.01). Anti-PML+/Sp100+ patients had more advanced disease compared to patients negative for anti-PML/Sp100 (p=0.04).

CONCLUSION

The new line immunoassay offers a robust and accurate method for the detection of clinically-relevant PBC-specific anti-MND antibodies.

Intrahepatic IgG/IgM plasma cells ratio helps in classifying autoimmune liver diseases

BACKGROUND/AIM

Plasma cells infiltrate in the liver is a prototype lesion of autoimmune liver diseases. The possible role of plasma cells isotyping (IgM and IgG) in the liver in the diagnostic definition of autoimmune liver disease, and particularly in variant syndromes such as autoimmune cholangitis and the primary biliary cirrhosis/autoimmune hepatitis overlap syndrome, is less defined.

METHODS

We analysed the clinical, serological and histological features of 83 patients with autoimmune liver disease (40 primary biliary cirrhosis, 20 autoimmune hepatitis, 13 primary sclerosing cholangitis, 4 autoimmune cholangitis and 6 overlap syndrome) compared to 34 patients with chronic hepatitis C and evaluated the expression of IgM and IgG plasma cells in their liver by immunostaining.

RESULTS

By Spearman's correlation, the mean-counts of IgM plasma cells in portal tracts were significantly correlated with female gender, serum alkaline phosphatase, gamma-glutamyl transferase and IgM values, positivity for anti-mitochondrial antibody-M2 and, on liver biopsy, with bile duct changes, orcein-positive granules and granulomas. Whereas IgG plasma cells resulted more correlated with alanine aminotransferase levels. IgG/IgM ratio lower than 1 was found no only in primary biliary cirrhosis but also in all patients with autoimmune cholangitis. Conversely, all patients with overlap syndrome showed IgG/IgM ratio higher than 1.

CONCLUSION

Immunostaining for IgM and IgG plasma cells on liver tissue can be a valuable parameter for better diagnosis of autoimmune liver disease and also for variant or mixed syndromes.

PML nuclear body component Sp140 is a novel autoantigen in primary biliary cirrhosis

OBJECTIVES

Some patients with primary biliary cirrhosis (PBC) have antinuclear antibodies (ANAs). These ANAs include the "multiple nuclear dots" (MND) staining pattern, targeting promyelocytic leukemia protein (PML) nuclear body (NB) components, such as "speckled 100-kD" protein (Sp100) and PML. A new PML NB protein, designated as Sp140, was identified using serum from a PBC patient. The aim of this study was to analyze the immune response against Sp140 protein in PBC patients.

METHODS

We studied 135 PBC patients and 157 pathological controls with type 1 autoimmune hepatitis, primary sclerosing cholangitis, and systemic lupus erythematosus. We used indirect immunofluorescence and a neuroblastoma cell line expressing Sp140 for detecting anti-Sp140 antibodies, and a commercially available immunoblot for detecting anti-Sp100 and anti-PML antibodies.

RESULTS

Anti-Sp140 antibodies were present in 20 (15%) PBC patients but not in control samples, with a higher frequency in antimitochondrial antibody (AMA)-negative cases (53 vs. 9%, P<0.0001). Anti-Sp140 antibodies were found together with anti-Sp100 antibodies in all but one case (19 of 20, 90%) and with anti-PML antibodies in 12 (60%) cases. Anti-Sp140 positivity was not associated with a specific clinical feature of PBC.

CONCLUSIONS

Our study identifies Sp140 as a new, highly specific autoantigen in PBC for the first time. The very frequent coexistence of anti-Sp140, anti-Sp100 and anti-PML antibodies suggests that the NB is a multiantigenic complex in PBC and enhances the diagnostic significance of these reactivities, which are particularly useful in AMA-negative cases.

Expression of bcl-2 in ductular proliferation is related to periportal hepatic stellate cell activation and fibrosis progression in patients with autoimmune cholestasis

AIM

To study bcl-2 expression in ductular proliferation cholangiocytes and hepatic stellate cell activation in liver biopsies from patients with autoimmune cholangitis and primary biliary cirrhosis.

MATERIALS AND METHODS

Twenty-four primary biliary cirrhosis patients and 11 autoimmune cholangitis patients were included. Thirty-four females, average age: 52.5+/-12.6 years. We studied the presence of ductular proliferation, cholestasis, florid ductal lesion, granulomata, ductopenia and histologic stage. Patients were classified in primary biliary cirrhosis or autoimmune cholangitis according to antimitochondrial antibodies, antinuclear antibodies, smooth muscle antibody, antiGP210 and antiSP100 autoantibodies. We studied the presence of bcl-2 by monoclonal antibcl-2 antibody (clon 100, BioGenex). The presence of activated (specific antialpha-actin antibodies) and independent lobular, periportal and portal hepatic stellate cell was assessed using a semiquantitative scale.

RESULTS

Interlobular ducts bcl-2 was seen in 18 (51.4%) patients. Activated periportal hepatic stellate cell correlated with Ludwig's stage (r=0.43; n=35; p=0.01). Ten out of 15 (66.6%) patients with ductular proliferation showed positive interlobular ducts bcl-2 while bcl-2 was negative in 8 out of 20 (40%) patients without ductular proliferation; p<0.05. Bcl-2 positive patients in ductular proliferation showed a more advanced Ludwig's stage (2.33+/-0.77 versus 1.26+/-1.05; p<0.05) and a higher periportal hepatic stellate cell activation index (0.83+/-0.78 versus 0.23+/-0.43; p=0.009). No relationship was found among periportal hepatic stellate cell activation and the presence of florid ductal lesion, cholestasis, granulomata or biliary erosive necrosis. Hepatic stellate cell activation was similar in patients with either autoimmune cholangitis or primary biliary cirrhosis.

CONCLUSIONS

Periportal hepatic stellate cell activation seems to play a main role in fibrosis progression in patients with autoimmune cholestasis. Bcl-2 expression in ductular proliferation may promote hepatic stellate cell activation and fibrosis.