This happens about 2-3% of the time in people with celiac disease and can lead to false-negative test results. Common tests for celiac disease include: 1  Anti-tissue transglutaminase antibody (anti-tTG), IgA: detects antibodies to tissue transglutaminase, an enzyme that causes the crosslinking of certain proteins. 2  Anti-tTG, IgA is the most sensitive and specific blood test for celiac disease.
A contour line is a line drawn on a topographic map to indicate ground elevation or depression. A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line.
Contour lines normally connect areas with equal data values, so may generally be called isolines or isopleths-lines of the same value. Normally, the primary set of contour lines is displayed as a solid line, while the secondary contour is displayed as a &shed line. For example, a standard 850-hPa, 24-hour prognosis chart has height contours in solid lines, temperature contours in dashed lines, and wind speed and direction as plotted data.