The Diagnostic Value Of Combined Detection Of Hematological Indicators For Abdominal IgA Vasculitis In Children With Abdominal Pain As The Initial Symptom

Objective: To investigate the diagnostic value of hematological indices in children with abdominal IgA vasculitis with abdominal pain as the first symptom and the advantages of combined diagnosis.To provide clinical ideas for the diagnosis of abdominal IgA vasculitis in children with only abdominal pain as the first symptom.Methods:A total of 430 children aged 2-14 years who were first diagnosed with abdominal IgA vasculitis in children,acute simple appendicitis in children,and simple skin IgA vasculitis in children from January 2019 to December 2022 in Shengjing Hospital of China Medical University were included in this study,and their hematological indices,including blood routine and its derived indices,C-reactive protein,coagulation indices,immunoglobulins,and The independent risk factors for the development of abdominal IgA vasculitis in children with abdominal pain as the first symptom were clarified by binary logistic stepwise regression analysis,and a diagnostic model was established;the diagnostic efficacy of each diagnostic model for the diagnosis of abdominal IgA vasculitis with only abdominal pain as the first symptom was compared by working curves of subjects,and the area under the curve(AUC)was compared by Z test to explore the diagnostic efficacy of each diagnostic model for the diagnosis of abdominal IgA vasculitis.We also used the Hosmer-Lemeshaw test to determine the goodness of fit of each diagnostic model,compared the calibration of each diagnostic model for disease diagnosis,and explored the best hematological indexes for diagnosis and the advantages of their combined diagnosis.Finally,we used the chi-square test and the Kruskal-Wallis test to compare the differences in the indicators between groups of children with the same symptoms or the same disease,and analyzed the relationship between the detected indicators and the clinical symptoms of abdominal IgA vasculitis.Results: Children with abdominal IgA vasculitis with abdominal pain as the first symptom had higher D dimer and IgA than in the acute simple appendicitis group(p <0.05)and lower albumin than in the acute simple appendicitis group(p < 0.05).Among them,albumin alone(AUC=0.095)had no diagnostic value,and the combined D-dimer+IgA+albumin test(AUC=0.975)had good diagnostic efficacy,but the model fit was poor.The diagnostic efficacy of D-dimer alone(AUC=0.940),IgA alone(AUC=0.788),and D-dimer+IgA combination(AUC=0.959)was found to be better and the diagnostic model fit was good by comparison.z-test found that the diagnostic models of D-dimer+IgA+albumin combination and D-dimer+IgA combination The area under the curve(AUC)was not statistically different(p > 0.05),and the AUCs of the remaining diagnostic models were statistically different from each other,and the diagnostic efficacy of the combined D dimer + IgA assay was the highest.The best cut-off values(sensitivity,specificity)for the diagnosis of each test index were also obtained from the subjects’ working curves: IgA 1.525 g/L(55.7%,94.5%),D-dimer 442ug/L(90.0%,92.7%),and albumin 17.7 g/L(100%,0).Finally,the comparison of differences between groups showed that D dimer and IgA were elevated when abdominal IgA vasculitis occurred,and D dimer was more closely related to its abdominal pain symptoms,and IgA was more closely related to its skin rash symptoms.In conclusion,the combined D-dimer+IgA test had the highest diagnostic efficacy(AUC=0.959),with sensitivity and specificity of 88.6% and 98.2%,respectively,and good model fit of the diagnostic model,which had good diagnostic predictive efficacy for abdominal IgA vasculitis in children with only abdominal pain symptoms at the first presentation.Conclusion:1.Children with abdominal IgA vasculitis with abdominal pain as the first symptom had elevated D-dimer and IgA and decreased albumin.2.The combined detection of D-dimer and IgA is of clinical value to improve the diagnostic rate of abdominal IgA vasculitis in children and provide clinical ideas for the diagnosis of abdominal IgA vasculitis in children with only abdominal pain as the first symptom.