Construction and Validation of a Predictive Model for Culture Results of Mycobacterium Tuberculosis in Superficial Lymph Nodes

Qian Li, Leipeng Ren, Weitong Wu, Dangze Sun, Lin Wei, Chao Ding, Peijia Luo Department of Thoracic Surgery, Xi’an Chest Hospital, Xi’an, Shaanxi, 710100, People’s Republic of ChinaCorrespondence: Peijia Luo, Department of Thoracic Surgery, Xi’an Chest Hospital, Xi’an, Shaanxi, 710100, People’s Republic of China, Email [email protected]: To establish and validate a nomogram for predicting the culture results of Mycobacterium tuberculosis in superficial lymph nodes.Methods: The clinical data of patients with superficial lymph node tuberculosis admitted to Xi’an City Chest Hospital from November 23, 2018, to May 30, 2024, were selected and divided into a training set and a validation set according to a ratio of 7:3. Influencing factors were identified through multivariate logistic regression analyses. Using R version 4.3.2, we developed a predictive model and generated a nomogram based on this model. The performance of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration curve analysis (CCA), and decision curve analysis (DCA).Results: The positive rate of superficial lymph node tuberculosis culture was 23.0% (103/446). Multivariate Logistic regression analysis showed that anti-tuberculosis treatment duration (OR=0.98, 95% CI: 0.97 ~ 0.99), initial treatment or retreatment (OR=0.12, 95% CI: 0.05 ~ 0.28), and adenosine deaminase (OR=1.12, 95% CI: 1.03 ~ 1.22) were independent factors affecting the culture results of Mycobacterium tuberculosis in superficial lymph nodes. The areas under the ROC curves were 0.86 (95% CI: 0.82– 0.91) for the training set and 0.89 (95% CI: 0.84– 0.95) for the validation set. The P values of calibration curves were 1.000 and 0.961, respectively, and the predicted values were in good agreement with the actual values. The threshold probabilities of clinical decision curves were 3%~64% and 1%~68%, respectively.Conclusion: The positive rate of Mycobacterium tuberculosis culture in superficial lymph nodes is low. The increase in retreatment patients and anti-tuberculosis treatment time are obstacle factors for Mycobacterium tuberculosis culture positivity, while an increase in adenosine deaminase is a promoting factor for Mycobacterium tuberculosis culture positivity. The nomogram model established based on these factors can be used to predict the results of Mycobacterium tuberculosis culture in superficial lymph nodes.Keywords: superficial lymph node tuberculosis, mycobacterium culture, predictive model, nomogram