Endocrine Abstracts

Objectives: To analyze the conceptual frame for a correlation between thyroid echographic description and antithyroid peroxydase antibodies (ATPO) levels in Hashimoto’s thyroiditis (HT).

Material-methods: A. 783 patients: 396 with HT (ATPO>34 UI/ml), 386-control (ATPO<34 UI/ml). B. Ultrasound aspects were described in 8 patterns: 0-thyroid lack; 1 – hypoechogenic and pseudonodular; 2 – hypoechogenic and homogenous; 3 – hypoechogenic micronodular; 4 – macronodular (>10 mm), 5 – inhomogeneous hypoechogenic and pseudonodular; 6 – anechogenic micronodular; 7 – diffuse hyperechogenic (normal). C. ATPO was split into 9 intervals as: 0 – 34, 35 – 100, 101 – 350, 351 – 550, 551 – 800, 801 – 999, 1000 – 3000, 3001 – 5000, >5000 UI/ml.

Results: A. In HT cases, pattern - number: 0 – 2; 1 – 186; 2 – 53; 3 – 25; 4 – 75; 5 –39; 6 – 10; 7 –6. In controls: 0 - 1, 1 – 21; 2 –46; 3 –55; 4 –150; 5 –20; 6 – 21 7 – 73. B. Sensibility, specificity and positive predictive value (PPV): pattern 0: 51%, 99.74%, 66.67%; pattern 1: 46.97%, 94.56%, 89.86%; pattern 2: 12.28%, 88.08%, 53.54%; pattern 3: 6.31%, 85.55%, 31.25%; pattern 4: 18.04%, 61.14%, 34.44%; pattern 5: 9.85%, 24.82%, 66.1%; pattern 6: 2.53%, 94.56%, 33.26%; pattern 7: 1.52%, 81.09%, 7.54%. C. Correlation between serum ATPO and ultrasonographic patterns: χ² test (54 degrees of freedom)=100.94; P=0,0002.

Conclusions: 1. There are differences in sensitivity, specificity and positive predictive values for the 7 patterns. 2. When PPV is near 90%, as in pattern 1, the test may be very suggestive for HT. Therefore, “hypoechogenic-pseudonodular” type means HT in 90% cases. 3. PPV around 30% as in 3, 4, 6 patterns reveals low probably of HT. 4. In type 7, PPV of 7.54% reflects a very low possibility of HT.