ObjectiveTo establish a noninvasive diagnostic model for liver fibrosis in chronic hepatitis B （CHB） patients with normal alanine aminotransferase （ALT） and an age of ≤30 years by selecting specific indicators from the commonly used noninvasive indicators such as clinical， biochemical， and imaging indicators， to avoid invasive liver biopsy in such patients to some extent， and to guide the timing of antiviral therapy. MethodsA total of 251 CHB patients with normal ALT and an age of ≤30 years who underwent liver biopsy in Shenzhen Third People’s Hospital and The First Hospital of Changsha from January 2019 to January 2022 were enrolled， with 175 patients in the model group and 76 patients in the validation group， and commonly used clinical indicators were obtained based on clinical experience and related articles. The two-independent-samples t test or the two-independent-samples Mann-Whitney U rank sum test was used for comparison of continuous data between groups， and the chi-square test was used for comparison of categorical data between groups. A Spearman rank correlation analysis was used to investigate the correlation between each indicator and liver fibrosis and identify the indicators with correlation （P<0.01， r>0.200）； a Logistic regression analysis was used to establish a noninvasive diagnostic model， and the receiver operating characteristic （ROC） curve was used to evaluate its performance and perform validation of the model； this model was then compared with the widely used models of aspartate aminotransferase-to-platelet ratio index （APRI） and fibrosis-4 （FIB-4）. The Kappa consistency test was used to investigate the consistency of pathological results. ResultsA total of 17 commonly used clinical indicators were obtained， among which 9 indicators （ALT， aspartate aminotransferase ［AST］， gamma-glutamyl transpeptidase ［GGT］， ferritin ［FERR］， platelet count ［PLT］， procollagen type Ⅲ amino-terminal peptide ［PⅢP］， collagen Ⅳ ［CⅣ］， HBV DNA， and spleen thickness） were correlated with liver fibrosis （P<0.01， r>0.232）. Based on the above indicators， the predictive model was established as P=1/（1+e^-γ）， γ=-1.902+0.106×AST－0.011×PLT－0.265×HBV DNA+0.059×PⅢP， in which P was the probability for predicting ≥S2 liver fibrosis and γ was the predictive index. The comparison between each indicator and the model showed that the model had the largest area under the ROC curve of 0.852， with a sensitivity of 92.7% and a specificity of 76.9%. The model was validated in 76 patients and showed an accuracy of 77.600%. The model was compared with APRI and FIB-4， and the results showed that the model has good accuracy. ConclusionCompared with the models of APRI and FIB-4 commonly used in the world， this model can more accurately judge the degree of liver fibrosis in such patients， thereby replacing liver biopsy to some extent and guiding the timing of antiviral therapy.

ObjectiveTo predict whether antiviral therapy is required in patients with chronic hepatitis B virus （HBV） infection and an age of ≤30 years by establishing a noninvasive model， and to investigate the diagnostic value of this model. MethodsA retrospective analysis was performed for the clinical data of 175 patients with chronic HBV infection who were admitted to Shenzhen Third People’s Hospital from January 2017 to January 2023 and met the inclusion criteria， and according to the results of liver biopsy， they were divided into treatment group with 41 patients （with indications for antiviral therapy） and observation group with 134 patients （without indications for antiviral therapy）. The two groups were analyzed in terms of the indicators including clinical data， imaging examinations， and serum biochemical parameters. The univariate and multivariate Logistic regression analyses were used to investigate the parameters affecting the indication for antiviral therapy， and different models for predicting the need for antiviral therapy were constructed based on related parameters. The receiver operating characteristic （ROC） curve was used to compare the diagnostic value of different models. The independent-samples t test was used for comparison of normally distributed continuous variables between groups， and the Mann-Whitney U rank sum test was used for comparison of non-normally distributed continuous variables between groups； the chi-square test or the Fisher’s exact test was used for comparison of categorical data between groups. ResultsThere were significant differences between the treatment group and the observation group in alanine aminotransferase， ferritin， total cholesterol （CHOL）， triglyceride， platelet count， liver stiffness measured by sound touch elastography （STE）， and procollagen III N-terminal propeptide （PIIIP） （all P<0.05）. The multivariate Logistic regression analysis showed that CHOL （odds ratio ［OR］=0.4， 95% confidence interval ［CI］： 0.2‍ ‍—‍ ‍1.0）， STE （OR=1.5， 95%CI： 1.0‍ ‍—‍ ‍2.1）， and PIIIP （OR=1.1， 95%CI： 1.0‍ ‍—‍ ‍1.1） were independent predictive factors for the indications for antiviral therapy. Model 1 （STE+PIIIP+CHOL）， model 2 （STE+PIIIP）， model 3 （STE+CHOL）， model 4 （PIIIP+CHOL） had an area under the ROC curve of 0.908， 0.848， 0.725， and 0.725， respectively， while STE， PIIIP， and CHOL used alone had an AUC of 0.836， 0.725， and 0.634， respectively， suggesting that model 1 had the largest AUC， with a specificity of 77.34% and a sensitivity of 96.36%， and had a significant difference compared with STE， PIIIP， CHOL， and the models 2， 3， and 4 （Z=0.21， 3.08， 3.06， 3.23， 0.89， and 0.88， all P<0.05）. ConclusionThe noninvasive model established based on CHOL， STE， and PIIIP has a good value in predicting the need for antiviral therapy in patients with chronic HBV infection and an age of ≤30 years.