Diagnostic value of serum thymus and activation-regulated chemokine (TARC) in fatal asthma

Asthma, a chronic inflammatory airway disease, is characterized by airway hyperresponsiveness and structural changes. Accurate postmortem diagnosis is crucial because of legal and insurance implications, necessitating differentiation from other causes of sudden death. Thymus and activation-regulated chemokine (TARC) is a chemokine that potentially acts as a biomarker of asthma. This study evaluated the diagnostic value of serum TARC combined with immunoglobulin E (IgE) levels as biomarkers in forensic settings.

The subjects were 100 autopsy cases, categorized into fatal asthma (n = 25), acute myocardial infarction (AMI) (n = 37), and traumatic deaths (n = 38). TARC levels were significantly elevated in asthma (525.68 ± 801.87 pg/mL) compared with AMI (180.35 ± 109.37 pg/mL) and trauma (173.26 ± 105.01 pg/mL) cases. Similarly, serum IgE levels were higher in asthma (3363.72 ± 7023.46 KU/L) than in AMI (130.92 ± 260.79 KU/L) and trauma (134.53 ± 195.41 KU/L) cases. ROC curve analysis showed that serum TARC had a sensitivity of 68.0 % and specificity of 73.6 % (AUC 0.763, cut-off value of 225 pg/mL). In comparison, serum IgE had a sensitivity of 80 % and specificity of 86.1 % (AUC 0.881, cut-off value of 307 KU/L). The combined use of TARC and IgE increased the diagnostic specificity to 95.8 %.

Serum TARC and IgE are valuable biomarkers for diagnosing fatal asthma in forensic settings. While serum TARC levels correlate with Th2-mediated inflammation, the combined measurement of TARC and IgE enhances the diagnostic accuracy, providing significant specificity for confirming asthma diagnosis.