Prevalence of non-organ-specific autoantibodies in a rural community from northeastern Brazil: a population-based study.

Non-organ-specific autoantibodies (NOSA) are well-recognized diagnostic markers of autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC), but can also be observed in patients with viral hepatitis as well as in healthy subjects. The aim of this study was to evaluate the prevalence of NOSA in subjects living in a rural community in Brazil and to correlate their occurrence with the presence of liver disease. Seven hundred twenty-five apparently healthy subjects were randomly selected for assessment of antinuclear (ANA), anti-smooth muscle (SMA), antimitochondrial (AMA), anti-liver/kidney microsome type 1, and anti-liver cytosol type 1 antibodies. Subjects with those NOSA were evaluated for the presence of AIH, PBC, and viral hepatitis. Reactivities for all NOSA, SMA, ANA, and AMA were detected, respectively, in 14, 10, 4, and 0.1% of subjects, with a mean titer of 1:40. NOSA-positive subjects were significantly older and more frequently females. No correlation was observed between the occurrence of NOSA and PBC, AIH, or viral hepatitis. The prevalence of NOSA in Brazilians was 14%. They were usually low titer. NOSA were more frequently observed in females and older subjects and their presence was not correlated with the presence of AIH, PBC, or viral hepatitis.

A contribution to the diagnosis of Capillaria hepatica infection by indirect immunofluorescence test.

A highly specific pattern of immunofluorescence was noted when sera from Capillaria hepatica-infected rats were tested against the homologous worms and eggs present either in paraffin or cryostat sections from mouse liver. The pattern was represented by a combined apple green fluorescence of the internal contents of worms and eggs, which persisted in serum-dilutions of 1:400 up to 1:1600. Unequivocal fluorescent pattern was observed from 15 days up to 3 months following inoculation of rats with embryonated C. hepatica eggs and such result was confirmed by the ELISA. After the 4th month of infection, the indirect immunofluorescence test turned negative, probably revealing the extinction of parasitism, however the ELISA was contradictory, disclosing high levels of antibodies in this period. The IIF was also negative when control normal rat sera and sera from rats administered by gavage with immature C. hepatica eggs (spurious infection), or for reactions made against Schistosoma mansoni eggs, although a weakly positive pattern occurred with Fasciola hepatica eggs. The indirect immunofluorescence test may be recommended for use with human sera to detect early C. hepatica infection in special clinical instances and in epidemiological surveys, since it is a simple, inexpensive, and reliable test, presenting excellent sensitivity and specificity. Although the diagnosis is positive only during early infection, this is the period when the symptoms are usually more severe and the need for differential diagnosis is greater.

Frequency of celiac disease and its serological markers in patients with autoimmune hepatitis

Transglutaminase (anti-tTG) and anti-endomysial (AEA) antibodies were reported to occur in patients with autoimmune hepatitis (AIH) as well as in subjects with advanced cirrhosis, but the prevalence of celiac disease (CD) in patients with AIH is either negligible or unknown. The frequency of IgA anti-tTG and IgA AEA was determined in 64 patients (54 females, mean age 19[5-67] years ) with AIH diagnosed according to international criteria. Patients with positive or intermediate results for those antibodies were submitted to duodenal biopsy and HLA-DQ2 or DQ8 typing. Anti-tTG and AEA were detected in 6 (9 por cento) and one patient (1.6 por cento) with AIH, respectively. Positive and borderline results for IgA anti-tTG were detected, respectively, in two (3 por cento) and four (6 por cento) patients. Only one patient with HLA-DQ2 and IgA anti-tTG and IgA AEA had CD on duodenal biopsy. Two patients with either positive or borderline results for IgA anti-tTG antibody and HLA-DQ2 had normal histology on duodenal biopsy. IgA anti-tTG antibody and/or AEA were observed in 9% of AIH patients, but CD was confirmed in only one of them. The occurrence of IgA anti-tTG antibody in the other patients could be ascribed to the presence of chronic liver disease or to latent or potential CD.

A contribution to the diagnosis of Capillaria hepatica infection by indirect immunofluorescence test

A highly specific pattern of immunofluorescence was noted when sera from Capillaria hepatica-infected rats were tested against the homologous worms and eggs present either in paraffin or cryostat sections from mouse liver. The pattern was represented by a combined apple green fluorescence of the internal contents of worms and eggs, which persisted in serum-dilutions of 1:400 up to 1:1600. Unequivocal fluorescent pattern was observed from 15 days up to 3 months following inoculation of rats with embryonated C. hepatica eggs and such result was confirmed by the ELISA. After the 4th month of infection, the indirect immunofluorescence test turned negative, probably revealing the extinction of parasitism, however the ELISA was contradictory, disclosing high levels of antibodies in this period . The IIF was also negative when control normal rat sera and sera from rats administered by gavage with immature C. hepatica eggs (spurious infection), or for reactions made against Schistosoma mansoni eggs, although a weakly positive pattern occurred with Fasciola hepatica eggs. The indirect immunofluorescence test may be recommended for use with human sera to detect early C. hepatica infection in special clinical instances and in epidemiological surveys, since it is a simple, inexpensive, and reliable test, presenting excellent sensitivity and specificity. Although the diagnosis is positive only during early infection, this is the period when the symptoms are usually more severe and the need for differential diagnosis is greater.