9303 Evaluation of The Consistency of Thyroid Indicators Tests in Minimally Invasive Peripheral Blood and Venous Blood

Abstract Disclosure: Z. Zhu: None. Y. Huang: None. Z. Cao: None. L. Zhang: None. D. Wang: None. S. Wang: None. J. Zhang: None. Y. Gao: None. Y. Zhang: None. Background The detection of thyroid indicators is of high demand in clinical and epidemiological screenings. Compared with existing venous blood tests, peripheral fingertip blood tests are less invasive and have a lower blood collection volume, which is the basis for point-of-care tests of thyroid indicators. Objective To explore the feasibility of minimally invasive and micro blood collection tests for thyroid disease (TD) patients by evaluating the consistency of thyroid indicators and TD diagnostic efficiency between fingertip blood tests and venous blood tests. Method 63 subjects with or without thyroid dysfunction were consecutively recruited. All subjects underwent serum, plasma and fingertip blood (same day collection) measurements for TSH and TT4 detection via the chemiluminescence method and for TPOAb detection via the electrochemiluminescence immunoassay method. The fingertip blood was centrifuged and diluted after EDTA anticoagulation. Bland–Altman plot, Passing–Bablok regression, and weighted kappa test were used for consistency test; AUC of ROC curve, sensitivity and specificity were used for authenticity evaluation among the three collection and testing methods. Results 43 subjects with euthyroidism and 20 subjects with thyroid dysfunction were included; including 29 (46.03%) females, the average age was 50.98±14.76 years. Bland-Altman plots showed more than 90% of the subjects had TSH and TT4 differences within the 95% limits of agreement between peripheral blood (PB) and venous blood (including serum and plasma). Passing–Bablok regression analyses revealed strong correlations between TSH levels in PB and serum (r=0.888) and plasma (r=0.894) (p<0.05); for TT4, there was a strong correlation between PB and serum (r=0.746), and there was also a moderate correlation between PB and plasma (r=0.664) (p<0.05 for both). Weighted kappa tests were performed for low, normal and high TSH values, indicating strong consistency between PB and serum and between PB and plasma, with coefficients of 0.901 and 0.881, respectively (P<0.001); for TT4, the coefficients between PB and serum, PB and plasma were 0.541 and 0.585 (P<0.001), indicating moderate consistency. Regardless of TPOAb positivity or negativity, the consistency among three blood sample sources was 100%. For euthyroidism (n=43), hyperthyroidism (n=6), subclinical hyperthyroidism (n=9), hypothyroidism (n=1), and subclinical hypothyroidism (n=4), the diagnostic sensitivities of PB were 97.06%, 83.33%, 87.50%, 100%, and 75.00%, respectively; the specificities were 94.74%, 97.87%, 95.74%, 98.11%, and 100.00%, respectively. The AUC of PB ROC curve for determining thyroid dysfunction was 0.944 (95% CI 0.867-1.000). Conclusion PB tests of thyroid indicators has high consistency with venous blood tests, offers sufficient diagnostic efficiency for TD, and is a feasible minimally invasive detection method. Presentation: 6/1/2024