Comparación entre el método enzimoinmunoensayo y la quimioluminiscencia, para la cuantificación de hormonas tiroideas

Objective: To compare the sensitivity and specificity of enzyme immunoassay versus chemiluminescence for the quantification of thyroid hormones. Methods: This was a quantitative, observational, and cross-sectional study. The population consisted of 407 blood samples from patients seen at the outpatient endocrinology clinic, with a final sample of 211 patients selected based on eligibility criteria. Thyroid hormone levels were measured using both enzyme immunoassay and chemiluminescence methods. A comparative analysis was performed to calculate sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results: The chemiluminescence method identified 68% of patients as negative and 32% as having thyroid disorders, all consistent with clinical fndings. The enzyme immunoassay reported 79% as negative and 21% as positive, of which 19% were true positives and 2% false positives. Additionally, 66% were true negatives and 13% false negatives. For the enzyme immunoassay, sensitivity was 57.9% and specificity 96.5%. The PPV was 88.9%, and the NPV was 83.6%. In contrast, the chemiluminescence method showed sensitivity, specificity, PPV, and NPV values exceeding 98%. The Kappa index was 0.6, indicating moderate agreement, where a value closer to 1 is ideal. Conclusions: The chemiluminescence method proved to be more sensitive and specific than enzyme immunoassay, making it the preferred method for quantifying thyroid hormones.