Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0268596 (EMA)
 2,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To assess the usefulness of enzyme inhibition assay for the diagnosis of primary biliary cirrhosis (PBC), we determined the serial changes in enzymatic inhibitory antibody to pyruvate dehydrogenase complex (PDC) in patients with PBC, and compared the results to those of immunofluorescence and immunoblotting. Forty-nine sera from 19 patients with PBC who were followed-up for at least 16 months were tested for antimitochondrial antibodies (AMA) by indirect immunofluorescence, immunoblotting on bovine heart mitochondria, and enzyme inhibition assay using commercially available TRACE Enzymatic Mitochondrial Antibody (M2) Assay (EMA) kit. Of the 49 sera, 39 (80%), 35 (71%), 38 (78%), 31 (63%), and 36 (73%) were positive for AMA by immunofluorescence, for immunoglobulin G (IgG), IgM, and IgA class antibody against E2 subunit of PDC (PDC-E2) by immunoblotting, and for enzymatic inhibitory antibody to PDC by EMA, respectively. AMA titers determined by immunofluorescence did not change in 9 patients (47%), increased in 4 (21%), decreased in 3 (16%), and fluctuated in 3 (16%) during follow-up. The number of anti-M2 bands by immunoblotting did not change in 9 (47%), increased in 6 (32%), decreased in 2 (11%), and fluctuated in 2 (11%). Units of PDC activity by EMA did not change markedly in 16 (84%), increased in 2 (11%), and fluctuated in 1 (5%). Positive EMA results were common in cases with high levels of serum alkaline phosphatase and IgM, and the units of PDC activity by EMA correlated significantly and inversely with AMA titers by immunofluorescence, and serum reactivity to PDC-E2 by immunoblotting, respectively. There was no correlation between serial changes in biochemical data and units of PDC activity by EMA. In three patients who showed a decrease in AMA titers, AMA titers correlated more with EMA results than immunoblotting. Moreover, in a patient with fluctuating AMA titers, the units of PDC activity by EMA paralleled AMA titers. Our results suggest that EMA is useful for the diagnosis of AMA-positive PBC, and also could be used for monitoring the disease course in PBC.
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PMID:Serial changes in enzyme inhibitory antibody to pyruvate dehydrogenase complex during the course of primary biliary cirrhosis. 1101 98

An association between celiac disease (CD) and other autoimmune diseases such as connective tissue diseases (CTD), inflammatory bowel diseases (IBD), and primary biliary cirrhosis (PBC) has been reported in several studies. However, a high rate of false positives in autoantibody testing was noted, especially when tissue transglutaminase (tTG) from guinea pig liver was used. Thus, the real prevalence of CD in CTD, IBD, and PBC is unclear. In a case-control study, 400 patients with CTD, 170 with IBD, 48 with PBC, and 120 healthy subjects were investigated for CD by the analysis of IgA and IgG tTG antibodies using the more specific human recombinant tTG immunoenzymatic assay. Patients and controls with positive findings were further tested for antiendomysial antibodies by indirect immunofluorescence and HLA typing, and those found positive by either of these tests underwent duodenal biopsy to confirm a possible diagnosis of CD. Twelve patients were positive for IgA or IgG tTG antibodies, showing an overall prevalence of 1.9%. Only 1 healthy subject (0.8%) had a low level positive reaction for IgA anti-tTG. Among the 12 patients and the healthy subject, only 2 (1 SLE and 1 ulcerative colitis patient) were subsequently confirmed to be affected with CD by positive EMA, HLA, and small bowel biopsy findings. The highest rate of false positives was found in PBC patients (10.4%). For these reasons, serological screening testing for CD is not recommended in CTD patients or in subjects affected with IBD or PBC, unless there is a relevant clinical suspicion of CD.
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PMID:IgA and IgG tissue transglutaminase antibody prevalence and clinical significance in connective tissue diseases, inflammatory bowel disease, and primary biliary cirrhosis. 1471 25