Background The Xpert MTB/RIF showed high sensitivity and specificity in previous studies carried out in different epidemiological and geographical settings and patient populations in high-burden tuberculosis (TB) countries.However,there were little data obtained by validation or demonstration study of the assay in China.In this study,the performance of Xpert MTB/RIF was investigated in two county-level laboratories in Hunan Province,China.Methods Consecutive patients with suspected pulmonary tuberculosis (PTB) and suspicion for multidrug-resistant tuberculosis (MDR-TB) were enrolled.For each patient suspected to have PTB,three sputum specimens (one spot sputum,one night sputum,and one morning sputum) were collected and each sputum was tested with smear microscopy,L(o)wenstein-Jensen (LJ) culture,and Xpert MTB/RIF test.For comparison across subgroups and testing methods,95％ confidence intervals were calculated.All analyses were done with SPSS 16.0,and P ＜0.05 was regarded as significant.Results For case detection,the sensitivity of Xpert MTB/RIF was 100％ for smear-and culture-positive TB and 88.6％ for smear-negative and culture-positive TB; the overall sensitivity was 94.5％ for all culture-positive patients.The specificity was 99.8％.The sensitivity of Xpert MTB/RIF assay was 22.0％ in clinical TB patients and the specificity reached 100.0％ in the group of patients who are infected with nontuberculous mycobacteria.For the detection of rifampin resistance,the sensitivity of MTB/RIF RIF-resistance detection was 92.9％,and the specificity was 98.7％.Of the 26 Xpert MTB/RIF-positive and RIF-resistant patients confirmed by LJ proportion tests,20 (76.9％) patients were infected by MDR-TB.Conclusions The Xpert MTB/RIF assay is a highly sensitive and specific method for diagnosis of TB and RIF resistance,which will enable it to have the potential to be used in county-level laboratories and lead to the reduction of the infectious pool and improvements in TB control in China.Further evaluations in county-level laboratories for implementing the assay are still required.

Objective:To investigate the clinicopathological features, immunophenotype, molecular characteristics, and differential diagnosis of primary intracranial DICER1-mutant sarcoma in order to better understand this tumor type.Methods:A retrospective analysis was conducted on 7 cases of primary intracranial DICER1-mutant sarcoma diagnosed in the Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China between 2021 and 2023 using next-generation sequencing. At the same time, 10 gliosarcomas, 4 intracranial FET::CREB fusion-positive mesenchymal tumors, 4 malignant meningiomas, 3 malignant solitary fibrous tumors, 3 malignant peripheral nerve sheath tumors, 3 synovial sarcomas and 3 rhabdomyosarcomas (total 30 cases) were selected as control.Results:Among the 7 patients with primary intracranial DICER1-mutant sarcoma, 6 were male and 1 was female, aged 10-32 years (median, 23 years). The tissue morphology was predominantly spindle or pleomorphic sarcoma-like, with 6 cases exhibiting eosinophilic globules, and 3 cases showing rhabdomyoblastic or rhabdomyosarcoma-like cell differentiation. Immunohistochemistry revealed focal desmin expression in 3 cases (3/7), ATRX loss in 3 cases (3/7), and p53 mutant pattern in 4 cases (4/7). Additionally, 4 cases (4/7) showed focal or diffuse SALL4 expression, whereas the control cases (30 cases) did not exhibit SALL4 protein expression, suggesting that SALL4 may possess certain auxiliary diagnostic value. Next-generation sequencing confirmed that all 7 cases of primary intracranial DICER1-mutant sarcoma harbored mutations in the DICER1 gene, with 5 cases having the mutation site at p.E1813D. Until May 2024, all 7 patients were alive.Conclusions:Primary intracranial DICER1-mutant sarcoma is a rare tumor. Understanding its morphological characteristics, immunohistochemical and molecular markers and differential diagnosis is crucial to avoid misdiagnosis and to improve diagnostic accuracy of this tumor.

BACKGROUNDThe Xpert MTB/RIF showed high sensitivity and specificity in previous studies carried out in different epidemiological and geographical settings and patient populations in high-burden tuberculosis (TB) countries. However, there were little data obtained by validation or demonstration study of the assay in China. In this study, the performance of Xpert MTB/RIF was investigated in two county-level laboratories in Hunan Province, China.

METHODSConsecutive patients with suspected pulmonary tuberculosis (PTB) and suspicion for multidrug-resistant tuberculosis (MDR-TB) were enrolled. For each patient suspected to have PTB, three sputum specimens (one spot sputum, one night sputum, and one morning sputum) were collected and each sputum was tested with smear microscopy, Löwenstein-Jensen (LJ) culture, and Xpert MTB/RIF test. For comparison across subgroups and testing methods, 95% confidence intervals were calculated. All analyses were done with SPSS 16.0, and P < 0.05 was regarded as significant.

RESULTSFor case detection, the sensitivity of Xpert MTB/RIF was 100% for smear- and culture-positive TB and 88.6% for smear-negative and culture-positive TB; the overall sensitivity was 94.5% for all culture-positive patients. The specificity was 99.8%. The sensitivity of Xpert MTB/RIF assay was 22.0% in clinical TB patients and the specificity reached 100.0% in the group of patients who are infected with nontuberculous mycobacteria. For the detection of rifampin resistance, the sensitivity of MTB/RIF RIF-resistance detection was 92.9%, and the specificity was 98.7%. Of the 26 Xpert MTB/RIF-positive and RIF-resistant patients confirmed by LJ proportion tests, 20 (76.9%) patients were infected by MDR-TB.

CONCLUSIONSThe Xpert MTB/RIF assay is a highly sensitive and specific method for diagnosis of TB and RIF resistance, which will enable it to have the potential to be used in county-level laboratories and lead to the reduction of the infectious pool and improvements in TB control in China. Further evaluations in county-level laboratories for implementing the assay are still required.

Adult ; Antibiotics, Antitubercular ; therapeutic use ; China ; Female ; Humans ; Male ; Middle Aged ; Rifampin ; therapeutic use ; Tuberculosis ; diagnosis ; drug therapy ; Tuberculosis, Multidrug-Resistant ; Tuberculosis, Pulmonary ; diagnosis ; drug therapy ; Young Adult