IgA anticardiolipin and IgA anti-ß2 glycoprotein I antibody positivity determined by fluorescence enzyme immunoassay in primary antiphospholipid syndrome.

BACKGROUND: Primary antiphospholipid syndrome (PAPS) is an autoimmune disease characterized by thrombosis and/or pregnancy morbidity as well as blood antiphospholipid (aPL) antibodies such as anticardiolipin (aCL), anti-ß2 glycoprotein I (anti-ß2GPI) antibodies of the IgG/IgM isotype and lupus anticoagulant (LA). The clinical significance of aCL and anti-ß2GPI antibodies of the IgA isotype in PAPS is still a controversial issue. METHODS: Sera and plasma were collected from 84 PAPS patients (54 with thrombosis and/or pregnancy morbidity and 30 with pregnancy morbidity alone), 66 seronegative patients (subjects with clinical manifestations of PAPS although with negative results on conventional antiphospholipid antibody testing), and 78 healthy blood donors. IgA aCL and IgA anti-ß2GPI were determined using fluorescence enzyme immunoassay (FEIA), (EliATM, Phadia AB, Uppsala, Sweden). For comparison purposes, the sera were also tested for IgG/IgM aCL/anti-ß2GPI antibodies using the same immunoassay method. LA was assayed following internationally accepted guidelines. RESULTS: Present respectively in 19% and 50% of the PAPS patients studied, IgA aCL and IgA anti-ß2GPI antibody frequencies were both statistically significant (p=0.001 and p<0.001, respectively). The mean titers of both IgA aCL and IgA anti-ß2GPI antibodies were higher in the thrombotic patients, but only the latter were significantly associated with thrombosis. Isolated IgA anti-ß2GPI antibody positivity was significantly prevalent (p=0.04) in seven (10.6%) of the seronegative patients. CONCLUSIONS: Positivity to IgA anti-ß2GPI antibody detected using FEIA was found to be clinically relevant in PAPS patients. Moreover the prevalence of isolated IgA anti-ß2GPI antibody positivity was significant in the seronegative patients.

What is behind the presence of anti-neutrophil cytoplasmatic antibodies in chronic liver disease?

BACKGROUND: Anti-neutrophil cytoplasm antibodies (ANCA) have been detected in serum from patients affected by autoimmune CLD, and to a lesser extent, in serum of patients affected by non autoimmune CLD. The clinical significance of ANCA in these disorders is still unclear. AIMS: To explore the clinical and diagnostic significance of ANCA in CLD. MATERIALS AND METHODS: Forty-five sera from patients affected by HCV- and HBV-related CLD (group 1), 29 sera from patients affected by alcohol-related CLD (Group 2) and 33 sera from patients affected by autoimmune-related liver diseases including chronic autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC), (Group 3) have been studied by using IIF and ELISA. RESULTS: A low correspondence between the ANCA positivity obtained by IFI and ELISA was observed. The positivity for at least one ANCA antigen was observed in 60.0% of Group 1, in 44.8% of Group 2 and in 72.7% of Group 3. The relation between the aetiology of the disease and the number of positive ANCA tests in ELISA was not significant. The relation between the MELD score and the number of ANCA positivity in patients with cirrhosis in the autoimmune-related CLD and in the viral-related CLD has been investigated. In both Groups a significant worsening of MELD at increasing number of ANCA positivity was found. Moreover in patients without cirrhosis in Group 3 an increase in the ALT and AST activity in patients with at least one ANCA positivity was observed. CONCLUSIONS: These data suggest that the finding of ANCA by ELISA is common not only in autoimmune CLD but, also in viral-related CLD. Patients with autoimmune-related CLD express more frequently a multiple antigen reactivity as compared to those with viral-related CLD. The positivity for ANCA might have a prognostic value in patients with viral-related as well as autoimmune-related cirrhosis since it is associated with worse MELD score.

A new indirect chemiluminescent immunoassay to measure anti-tissue transglutaminase antibodies.

OBJECTIVES: Anti-tissue transglutaminase antibody (anti-tTG) determination using second-generation (human antigen) enzyme-linked immunoassays (ELISAs) is a very accurate test to diagnose celiac disease (CD). In this study, we compared 2 second-generation ELISAs (Celikey tTG; Pharmacia Diagnostics GmbH & Co, Freiburg, Germany, and QuantaLite; Inova Diagnostics, San Diego, CA) and antiendomysial antibodies (EMAs) with a new indirect chemiluminescence immunoassay (LIAISON tTG; DiaSorin S.p.A., Saluggia, Italy) in diagnosing and monitoring CD in children. PATIENTS AND METHODS: Antiendomysial antibodies, anti-tTGs and total immunoglobulin A were measured in the sera of 103 control children, 101 children with histologically proven CD and 31 CD children on gluten-free diet (GFD). RESULTS: Anti-tissue transglutaminase antibody mean levels were significantly higher in CD with respect to control or GFD children. The sensitivity value of EMAs, LIAISON tTG, Celikey tTG and QuantaLite in diagnosing CD was 97.7%, 97.0%, 94.1% and 98.0%, respectively, and the corresponding specificity values were 91.1%, 98.1%, 97.1% and 96.1%, respectively. The degree of mucosal destruction (Marsh criteria) was correlated with EMA semiquantification (P < 0.01) and with the circulating levels of anti-tTGs measured using LIAISON (P < 0.05) or QuantaLite (P < 0.01). Twenty-six CD children were followed up from 5 to 25 months after GFD. The circulating levels of anti-tTGs measured with any of the 3 assays significantly dropped after GFD. CONCLUSIONS: Anti-tissue transglutaminase antibody determination with second-generation ELISAs is as effective as EMAs for CD diagnosis. The novel chemiluminescent method described in the present paper for the detection of anti-tTGs in the diagnosis of CD had the highest sensitivity and specificity values. The anti-tTG test correlates with the degree of mucosal destruction and is suitable for verifying patient compliance to dietary treatment.

Western blot immunoassay for HSP-70 antibodies in idiopathic tinnitus: a preliminary report.

OBJECTIVES: Our preliminary study investigated the role of nonspecific immunologic tests and immunoassay for heat shock protein 70 (HSP-70) in supporting the possibility of an autoimmune inner ear process determining idiopathic tinnitus. METHODS: Thirty-six consecutive patients with idiopathic tinnitus without other otologic or autoimmune diseases and 20 healthy blood donor subjects underwent determinations of circulating immune complexes (CICs) and other nonspecific immunologic factors and immunoassay for HSP-70. RESULTS: The mean CIC values were 4.2 microg/mL in the tinnitus patients and 0.9 microg/mL in the control group (p = .012). Thirteen of the 36 tinnitus patients and none of the control group were HSP-70-positive. Ten of the 13 HSP-70-positive patients had CIC values higher than normal. In the tinnitus group, the mean CIC values were 6.9 microg/mL and 2.6 microg/mL in the HSP-70-positive and -negative subgroups, respectively (p = .024). CONCLUSIONS: It may be hypothesized that in a significant number of cases, idiopathic tinnitus could be induced by immune response to inner ear-specific HSP-70.

Recent advances in diagnostic technologies for autoimmune diseases.

The investigation of autoimmunity provides an interest challenge in "omics" research and, particularly, proteome research, as autoimmune diseases are common disorders of unsolved etiology that occur in a wide range of manifestations, in all of which tissues and organs are attacked by the body's own immune system. Autoantibodies are a hallmark of many autoimmune diseases and the presence of autoantibodies is a distinctive and key characteristic of autoimmune diseases. Conventionally, the study of autoimmune response has always been conducted by analysing the presence and/or concentration of individual antibodies in biological fluids. New proteomic techniques allow the simultaneous identification/measurement of different autoantibodies in sera of patients suffering from autoimmune diseases. The possibility of simultaneously measuring a number of correlated analytes appears to be very interesting for analytical reasons (reduced volumes of biological samples, reagents and low costs), logistical/managerial reasons, and pathophysiological reasons (combination of markers in disease-oriented or organ-oriented profiling). In particular, we describe data collected by using high-throughput techniques such as antigen microarrays and mass spectrometry for antibody profiling. While recently collected data demonstrate satisfactory analytical sensitivity and reproducibility, some issues such as standardization and data interpretation have to be solved before the introduction of these new and promising techniques into clinical practice.