Fluctuating transglutaminase autoantibodies are related to histologic features of celiac disease  Edwin Liu, Fei Bao, Katherine Barriga, Dongmei Miao, Liping Yu, Henry A Erlich, Joel E Haas, George S Eisenbarth, Marian J Rewers, Edward J Hoffenberg  Clinical Gastroenterology and Hepatology  Volume 1, Issue 5, Pages 356-362 (September 2003) DOI: 10.1053/S1542-3565(03)00180-0

Figure 1 A summary of the 3 populations with high risk for CD. Of those screened with TGAA, subjects with persistent TGAA positivity were offered intestinal biopsy. Clinical Gastroenterology and Hepatology 2003 1, 356-362DOI: (10.1053/S1542-3565(03)00180-0)

Figure 2 Peak pre-biopsy and at-biopsy TGAA levels are compared in individuals with (A) normal and (B) positive intestinal biopsy results. In children with normal biopsy results, the TGAA level at the time of biopsy had decreased significantly from their peak pre-biopsy level (P = 0.013). Dotted lines represent a TGAA cutoff level of 0.5 that is useful in discriminating between normal and positive biopsy specimens. Clinical Gastroenterology and Hepatology 2003 1, 356-362DOI: (10.1053/S1542-3565(03)00180-0)

Figure 3 (A) Comparison in normal and positive biopsy specimens show that peak TGAA levels before biopsy was performed were significantly higher TGAA levels in those with positive biopsy results. Data are presented as median TGAA values (dashed line) with 25th and 75th percentiles (boxed area). Minimum and maximum ranges are delineated by vertical lines for each data set. (B) Similarly, TGAA levels at the time of biopsy were significantly higher in those with positive biopsy results compared to normal biopsy results. Data are presented as median TGAA values with 25th and 75th percentiles, with minimum and maximum ranges. Clinical Gastroenterology and Hepatology 2003 1, 356-362DOI: (10.1053/S1542-3565(03)00180-0)

Figure 4 (A) TGAA levels at the time of biopsy correlate with intestinal biopsy Marsh score when abnormalities are seen on histology. A TGAA level >0.5 (dotted line) is associated with a positive biopsy result (Fisher exact, P < 0.0001). (B) Analysis of various cutoff values for TGAA levels shows an autoantibody level of 0.5 and yields a positive predictive value (PPV) of 96% and a negative predictive value (NPV) of 65%. Clinical Gastroenterology and Hepatology 2003 1, 356-362DOI: (10.1053/S1542-3565(03)00180-0)

Figure 5 Dotted line in all figures represent normal TGAA level cutoff for positivity (0.05). (A) Illustration of a subject with persistently increased TGAA expression and a positive biopsy result at 9 years of age. This individual chose to remain on a normal gluten-containing diet. (B) Illustration of a subject with initial positive TGAA level and biopsy specimen consistent with CD. There is a decline in antibody and normalization of histology within 1 year following a gluten-free diet. (C) Illustration of a subject with a fluctuating course of TGAA levels. Small intestinal biopsy performed at a time when the TGAA level dropped to below 0.25 showed normal intestinal histology. (D) Illustration of a subject with fluctuating TGAA levels, an initial normal biopsy result, followed by an increase in TGAA levels and a subsequent positive biopsy result. Clinical Gastroenterology and Hepatology 2003 1, 356-362DOI: (10.1053/S1542-3565(03)00180-0)