Study on Blood MicroRNAs for Assisting Postmortem Diagnosis of Anaphylactic Shock

Background: Postmortem diagnosis of anaphylactic shock remains one of the challenges in forensic pathology due to the absence of specific pathological and morphological changes. MicroRNAs, characterized by tissue-specific expression and resistance to degradation, have been applied in forensic medicine for postmortem interval estimation and auxiliary diagnosis of certain causes of death. However, their utility in assisting the diagnosis of anaphylactic shock as a cause of death has not been previously reported in the literature. Thus, this study aimed to identify relevant microRNAs by constructing a search strategy for retrieval in the PubMed database and to validate and screen the selected indicators using collected blood samples. Materials and Methods: A literature search strategy was developed with a focus on “anaphylactic shock” and “microRNA” in PubMed. Relevant literature were screened, and microRNAs were extracted and compiled. Blood samples were collected from 8 cases of death due to anaphylactic shock and 22 cases of death from nonanaphylactic causes. RNA was extracted, and real-time polymerase chain reaction was performed to detect microRNAs. Relative expression levels were calculated for statistical analysis. Results: A total of 15 relevant literature were retrieved from PubMed. After extracting microRNAs and referencing with the miRBase and miRDB databases, 22 microRNAs were finally identified. Validation using postmortem blood samples revealed that the expression levels of 11 microRNAs were significantly higher in the anaphylactic shock group than in the control group (P < 0.05). Receiver operating characteristic analysis showed that 9 of 11 microRNAs had diagnostic efficacy, including miR-149-5p, miR-34a-5p, miR-181a-5p, miR-487b-3p, miR-182-5p, miR-154-5p, miR-451a, miR-155-3p, and miR-155-5p (P < 0.05). Among them, miR-182-5p exhibited the optimal diagnostic efficacy (area under the curve = 0.97). Conclusions: Postmortem detection of 9 microRNAs (miR-149-5p, miR-34a-5p, miR-181a-5p, miR-487b-3p, miR-182-5p, miR-154-5p, miR-451a, miR-155-3p, and miR-155-5p) in blood samples holds potential for assisting in the postmortem diagnosis of anaphylactic shock.