F.B. Bianchi

Antibodies to hepatitis C virus in autoimmune liver disease: evidence for geographical heterogeneity

To resolve conflicting reports about the occurrence of antibodies against hepatitis C virus (HCV) in patients with autoimmune chronic active hepatitis (AI-CAH), sera from UK and Italian patients were tested with the original anti-HCV assay (Ortho) and a novel anti-HCV assay (UBI) based entirely on synthetic HCV peptides. 28 (60%) of 47 Italian patients with type-1 AI-CAH were anti-HCV-positive by Ortho ELISA, 25 of whom were also strongly positive by the UBI assay. 15 (60%) of 25 UK patients with type-1 AI-CAH were HCV-positive by Ortho ELISA but only 2 were positive by the UBI assay. Similarly, 29 (88%) of 33 Italian patients with type-2 AI-CAH, but 0 of 10 UK patients, were very strongly anti-HCV-positive with the UBI assay. Italian patients with AI-CAH appear to have a high frequency of genuine exposure to HCV, whereas seropositivity by the Ortho HCV ELISA in UK patients is likely to represent a false-positive result. These findings indicate important geographical and/or genetic influences in autoimmune liver disease among different populations.

Desmin and actin in the identification of Ito cells and in monitoring their evolution to myofibroblasts in experimental liver fibrosis

SummaryIt has been reported that myofibroblasts contain actin and that Ito cells are positive for desmin. The distribution of desmin and actin detected by immunofluorescence, of vitamin A autofluorescence and of Sudan III staining of lipid droplets has been evaluated in sequential stages of experimental liver fibrosis induced in rats by intraperitoneal injections of swine serum. In the normal rat liver Ito cells were positive for desmin and weakly positive for actin. Prior to the development of hepatic fibrosis a clearcut increase in number and desmin staining of lobular Ito cells was observed in treated rats, but the overall actin pattern was unchanged. In the fibrotic rat livers, highly cellular septa contained large numbers of strongly desmin-positive, actin-weakly positive Ito cells and strongly desmin-and actin-positive myofibroblasts. These observations indicate that both Ito cells and myofibroblasts are positive for desmin, but only myofibroblasts contain large amounts of actin. Visualization of actin and desmin using relatively simple techniques, allows the monitoring of Ito cells proliferation, the accumulation of these cells in fibrous septa and their evolution into myofibroblasts as characterized by their increased desmin and actin content; it also allows an indirect evaluation of the process of fibrogenesis.

IgA antiendomysial antibody test. A step forward in celiac disease screening.

Serum IgA antiendomysial antibodies (EmA) were found in 61 (87%) of 70 adults and children with untreated celiac disease, whereas IgA antigliadin antibodies (AGA) and IgA R1-antireticulin antibodies (R1-ARA) were positive in 71% and 47%, respectively, of the same patients. Two of the nine untreated celiacs negative for IgA EmA showed positivity for IgA AGA. While IgA AGA and R1-ARA disappeared in all the celiacs, tested one year after gluten-free diet, IgA EmA persisted at low titer in seven (18%) of these 38 subjects, although the jejunal biopsy showed a complete regrowth of jejunal villi. All the disease control patients as well as the blood donors tested were always negative for the three IgA antibodies. Our results state that the search for both IgA EmA and AGA gives the best results in the screening of celiac disease, since the positivity for at least one of these two antibodies allows identification with a 100% specificity of the 90% of untreated celiac patients.

CAN ANTIGLIADIN ANTIBODY DETECT SYMPTOMLESS COELIAC DISEASE IN CHILDREN WITH SHORT STATURE

Duodenal biopsy and tests for antigliadin antibodies were done in 108 children with short stature unassociated with gastrointestinal symptoms. Other investigations for causes of growth failure were also carried out. In 88 patients, the cause of short stature could not be determined (group I). In 9 patients (8.3%) biopsy showed total villous atrophy, indicating probable coeliac disease (group II), while 7 patients had mild partial villous atrophy (group III). 4 patients (3.7%) had complete growth hormone deficiency. Antigliadin antibodies detected by immunofluorescence (IFL-AGA) were positive in 8 of the 9 group II patients. Symptomless coeliac disease is therefore a commoner cause of short stature than is hypopituitarism; by use of the IFL-AGA test it is possible to select patients for biopsy, thereby identifying most of the coeliac patients. If duodenal biopsies had been limited to IFL-AGA positive patients, 18 biopsies would have been carried out and coeliac disease would have been diagnosed in 8 of the 9 patients.

Immunomorphological characterisation of antinuclear antibodies in chronic liver disease.

Two immunofluorescence procedures to evaluate antinuclear antibodies were compared in a series of 221 patients with chronic liver disorders of various aetiologies. The use of HEp-2 cells allowed us to discriminate with more confidence between the homogeneous and speckled patterns, to show the presence of associated patterns in the same serum, and, above all, to identify two specificities, unrecognizable on tissue sections. The anticentromere antibody was found in 10% of cases of primary biliary cirrhosis and occasionally in other conditions; the antibody staining multiple nuclear dots was strictly confined to primary biliary cirrhosis (17%). With the exception of autoimmune chronic active hepatitis the prevalence of antinuclear antibodies increased in all groups, particularly in primary biliary cirrhosis. Homogeneous antinuclear antibody was associated by both immunofluorescence procedures with autoimmune chronic active hepatitis. The multiple nuclear dot antinuclear antibody turned out to be an additional marker of primary biliary cirrhosis, helpful for the positive diagnosis of primary biliary cirrhosis in a proportion of cases negative for antimitochondrial antibody. Absorption experiments showed that multiple nuclear dot and antimitochondrial antibody are antigenically distinct. Moreover, multiple nuclear dot antinuclear antibody was associated with the finding of a dry Schirmers test.

Anti-actin antibodies: a new test for an old problem.

Smooth muscle antibodies with anti-actin specificity are commonly regarded as markers of autoimmune liver disease. However, there are interpretational problems because different techniques have been used for their identification and therefore the results are difficult to compare. The present paper reports the results of a new method for the identification of anti-actin antibodies (indirect immunofluorescence on cryostat sections of liver from rats chronically injected with phalloidin). The results have been compared with those obtained by four other techniques: demonstration by immunofluorescence of kidney peritubular reactivity (SMAT), of anti-microfilament antibodies (on HEp-2 cells and vinblastine-treated peripheral blood mononuclear cells) and counterimmunoelectrophoresis with purified muscle actin as antigen. The new method proved to be the most sensitive and specific. Furthermore, its reproducibility was found to be high, the interpretation easy and the cost low. The clinical significance of anti-actin antibodies in patients with chronic liver disease is also discussed.

Prevalence and Characteristics of Coeliac Disease in Type 1 Diabetes Mellitus

Coeliac disease in patients with insulin-dependent diabetes mellitus has been reported (1-3) and the appearance of diabetes mellitus in subjects with coeliac disease in also well-known. In our recent study regarding a group of children with short stature (7), we reported that antigliadin antibody evaluation is the test most suited for this purpose. Thus, we used this method to study the exact prevalence of coeliac disease in a group of children and adolescents with type 1 diabetes mellitus. We examined 146 children and adolescents with insulin-dependent diabetes mellitus (IDDM) (76 males and 70 females) aged 2 3/12-22 7/12 years (mean k SD = 11.42?5.16), in whom duration of the disease varied from 0 to 17 2/12 years (mean f SD = 4.25k4.25). None of the children had gastrointestinal symptoms suggesting coeliac disease. A serum sample for antigliadin antibodies (AGA) as determined by immunofluorescence (IFL-AGA) (8) or by ELISA (ELISA-AGA) (6), islet cell antibodies (ICA), complement fixing islet cell antibodies (CfICA), thyorid microsomal (TMA), gastric parietal autoantibodies (PCA), liver-kidney microsome antibodies (LKM), non organ specific autoantibodies was obtained from each patient. Sixtynine patients were typed for HLA A, B, C and DR antigens. All patients who had antigliadin antibodies underwent jejunal biopsy. Informed consent was obtained from the parents and the children. Students t-test and 2 was used to analyze the results.

ANTI-NUCLEAR ANTIBODIES OF PRIMARY BILIARY CIRRHOSIS RECOGNIZE 78-92-KD AND 96-100-KD PROTEINS OF NUCLEAR BODIES

The specificities of anti‐nuclear antibodies (ANA) reacting with multiple nuclear dots (MND‐ANA) present in about 15% primary biliary cirrhosis sera were studied by Western blot analysis with nuclear fractions from a human cell line. Reactivity with two broad bands of 78–92 kD and 96–00 kD of the insoluble fraction was present exclusively in MND‐ANA‐positive sera. Antibodies eluted from these proteins specifically retained the immunofluorescence reactivity of MND‐ANA. Immunomorphological analysis by a pre‐embedding technique revealed that the antibody specifically binds to nuclear regions resembling in size and number nuclear bodies. Since these structures are absent in immature rate endometrial cell and can be induced by diethylstilbestrol. we tested MND‐ANA by immunofluorescence on cryostat sections of uteri from hormone‐treated and untreated immature rats. A strong reaction of nuclear dots was observed predominantly in endometrial cells of hormone treated rats. We thus conclude that MND‐ANA present in primary biliary cirrhosis sera are directed against 78–92‐kD and 96–100‐kD nuclear proteins located in nuclear bodies.

Anti‐cyclic citrullinated peptide antibodies in type 1 autoimmune hepatitis

Background : Besides the autoantibodies included in the diagnostic criteria of type 1 autoimmune hepatitis, many other autoantibodies have been described in this condition. Recently, antibodies against cyclic citrullinated peptide have been validated as specific diagnostic and prognostic markers of rheumatoid arthritis.

Auto-antibodies in hepatitis C

Hepatitis C virus (HCV) has been implicated in the development of a variety of autoimmune phenomena, some of which are well documented and include a panel of auto-antibodies shared with autoimmune hepatitis (AIH). Anti-nuclear (ANA) and smooth muscle (SMA) antibodies (markers of AIH type 1 [AIH-1]), have been demonstrated in 9-38% and 5-91% of cases respectively, whereas anti-liver/kidney microsomal type 1 (anti-LKM-1) and anti-liver cytosol type 1 antibodies (anti-LC1) (markers of AIH type 2 [AIH-2]), are definitely rarer, especially in adults. The presence of these auto-reactivities in chronic hepatitis C generates clinical overlaps and dilemmas in the correct classification and treatment of such patients. The immunopathological characterization of the auto-antibodies, anti-nuclear and smooth muscle antibodies in particular, combined with internationally defined criteria for the diagnosis of AIH is helpful in this clinical process. Thyroid auto-antibodies and cryoprecitable rheumatoid factors are also commonly detected in hepatitis C, while the occurrence of other auto-antibodies still awaits confirmation.