Radiological aspects in computed tomography as determinants in the diagnosis of pulmonary tuberculosis in immunocompetent infants

Identifying immunodeficiency status in children with pulmonary tuberculosis: using radiomics approach based on un-enhanced chest computed tomography

Background

Children with primary immunodeficiency diseases (PIDs) are particularly vulnerable to infection of Mycobacterium tuberculosis (Mtb). Chest computed tomography (CT) is an important examination diagnosing pulmonary tuberculosis (PTB), and there are some differences between primary immunocompromised and immunocompetent cases with PTB. Therefore, this study aimed to use the radiomics analysis based on un-enhanced CT for identifying immunodeficiency status in children with PTB.

Methods

This retrospective study enrolled a total of 173 patients with diagnosis of PTB and available immunodeficiency status. Based on their immunodeficiency status, the patients were divided into PIDs (n=72) and no-PIDs (n=101). The samplings were randomly divided into training and testing groups according to a ratio of 3:1. Regions of interest were obtained by segmenting lung lesions on un-enhanced CT images to extract radiomics features. The optimal radiomics features were identified after dimensionality reduction in the training group, and a logistic regression algorithm was used to establish radiomics model. The model was validated in the training and testing groups. Diagnostic efficiency of the model was evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, precision, accuracy, F1 score, calibration curve, and decision curve.

Results

The radiomics model was constructed using nine optimal features. In the training set, the model achieved an AUC of 0.837, sensitivity of 0.783, specificity of 0.780, and F1 score of 0.749. The cross-validation of the model in the training set showed an AUC of 0.774, sensitivity of 0.834, specificity of 0.720, and F1 score of 0.749. In the test set, the model achieved an AUC of 0.746, sensitivity of 0.722, specificity of 0.692, and F1 score of 0.823. Calibration curves indicated a strong predictive performance by the model, and decision curve analysis demonstrated its clinical utility.

Conclusions

The CT-based radiomics model demonstrates good discriminative efficacy in identifying the presence of PIDs in children with PTB, and shows promise in accurately identifying the immunodeficiency status in this population.

Tuberculosis and childhood cancer - A review of literature

Tuberculosis and malignancy are major public health problems in developing countries like India and causes significant morbidity and mortality. Mycobacterium tuberculosis is an aerobic acid-fast bacilli which is an important pathogen especially complicating clinical status of paediatric oncology patients and treatment of infection with this bacilli is challenging in this subpopulation of patients because of ongoing immunosuppression and relative lack of published guidelines. Atypical presentations of tuberculosis in children also complicate the diagnosis and management. All the more, in tuberculosis endemic area lung cancer may be mistakenly diagnosed as tuberculosis or vice versa and this wrong diagnosis increases the burden on country's health status. It is noted that tuberculosis prevalence is high in children with haematological malignancy and head and neck tumours compared to other solid organ tumours. Moreover, it is found that morbidity and mortality from tuberculosis is more in children from WHO listed high TB burden countries who undergo hematopoietic stem cell and solid organ transplantation. Use of immune checkpoint inhibitors as novel therapy in treatment of childhood malignancies has led to modification of the body's immunological response and has resulted in increased latent tuberculosis infection reactivation as one immune-related infectious consequence. Latent TB infection screening is important concept in management of paediatric oncology patients. Currently, the tests employed as screening diagnostics for LTBI are interferon-gamma release assay (IGRA) blood test and the tuberculin skin test (TST). Various regimens have been suggested for the treatment of LTBI. But, after a positive IGRA or TST and prior to latent TB treatment, active tuberculosis should be ruled out by detailed history taking, examination and appropriate investigations so as to minimize the risk of drug resistance with anti-tuberculosis monotherapy used in LTBI treatment. To add on to literature, Non tuberculous mycobacteria are universally present environmental organisms. However, in immunocompromised children especially in subpopulation of malignancy, NTM is known to cause infections which needs protocol based management. Also importance has to given to implementation of adequate preventive and corrective measures to prevent such opportunistic infection in paediatric oncology subpopulation. In this review, we provide an overview of tuberculosis in paediatric oncology patients and summarize the expansive body of literature on the tuberculosis mimicking carcinoma, tuberculosis burden in transplantation patients and those receiving immune check point inhibitors, latent TB infection screening and management, and NTM infection in children with malignancy.

The epidemiology of pulmonary tuberculosis in children in Mainland China, 2009-2015

OBJECTIVE

To describe the incidence and epidemiological characteristics of child pulmonary tuberculosis (PTB) notified to the Chinese Center for Disease Control and Prevention (CDC) Tuberculosis Information Management System (TBIMS) from 2009 to 2015.

STUDY DESIGN

A database of child PTB for 31 provinces in mainland China over 7 years was retrospectively analysed. The spatiotemporal distribution of child PTB was described.

RESULTS

In total, 35,710 child PTB cases were notified to the TBIMS, representing only 0.60% of all 5,991,593 PTB case notifications. The average annual notified incidence of child PTB was 2.44/ per 100,000 children (95% CI: 1.77-3.10) and decreased by 52.53% in all age groups during the study period. Tibet had the highest incidence (15.95/ per 100,000 children), followed by Guizhou and Xinjiang. However, the case numbers were the most in Guizhou. The 0-1 year and 12-14 years of age groups exhibited the most cases. The positive rates of sputum smears, bacteriology and chest X-rays abnormality were 21.5%, 21.7% and 98.1%, respectively, which were lower than those 15 years of age and older (all p-values<0.0001).

CONCLUSION

The notified incidence of child PTB in mainland China decreased substantially over 7 years. Future prevention and control of PTB in children should focus on the 0-1 and 12-14 years of age groups, and Tibet and Guizhou provinces. However, the notified incidence is still low, relative to adults, suggesting substantial under-reporting. Thus, more effective care seeking, identification and registration of children with TB are crucial.

Pulmonary tuberculosis in young people

Tuberculosis is a global health problem and the main cause of death in the whole world. Young individuals are significantly affected in the low- and medium income countries. The children are more often infected by close contact with familiar adults at home, and lung tuberculosis with cavities plays a major role in environmental contamination. Their primary infection may evolve to primary tuberculosis without specific manifestations. The diagnostic challenges may be solved by higher clinical suspicion index associated with complementary investigation tools including tuberculin skin test and chest X-rays. These comments aim to enhance the awareness of lung tuberculosis at younger ages.