Rationale: Use of Xpert MTB/RIF assay as a substitute for smear microscopy in routine clinical practice remains unexplored in an intermediate tuberculosis-burden setting. Objectives: To compare the diagnostic performance of Xpert and smear microscopy, based on sampling time and location, correlation of Xpert semiquantitative category with smear grade and time-to-culture positivity, and compliance of reporting time with defined standard time. Methods: Consecutive sputum samples collected from 2,952 suspected pulmonary tuberculosis patients over a 3-year-period were tested by Xpert, smear microscopy, and liquid culture as part of routine diagnostics in South Korea. Measurements and Main Results: Based on the analysis of a single-sputum-specimen per patient, of 2,952 samples, 263 (8.9%) were culture-confirmed tuberculosis and 265 (9.0%) were nontuberculous mycobacteria. The overall sensitivity and specificity were 74.1% and 97.5% for Xpert versus 38.8% and 96.7% for smear microscopy, respectively (P0.05). Of 82 smear-positive nontuberculous mycobacteria, 81 (98.8%) were accurately excluded by Xpert. Sampling time and location significantly affected the performance of smear microscopy, but not that of Xpert. Xpert semiquantitative category strongly correlated with smear grade (γ_{Goodman-Kruskal}=0.982, P<0.0001) and time-to-culture positivity (γ_{Goodman-Kruskal}=-0.962, P<0.0001). Median reporting time and its compliance rate within 24h were 3.1h and 96.3% for Xpert versus 19.1h and 88.7% for smear microscopy, respectively (P<0.0001; P<0.05). Conclusions: Xpert provides faster, more stable, and superior results compared to smear microscopy, in addition to its strong correlation with smear grade. Xpert might replace smear microscopy as the first-line diagnostic test for pulmonary tuberculosis in routine clinical practice in an intermediate-burden setting.

Mutations in genes that are part of the splicing machinery for myelodysplastic syndromes (MDS), including MDS without ring sideroblasts (RS), have been widely investigated. The effects of these mutations on clinical outcomes have been diverse and contrasting. We examined a cohort of 129 de novo MDS patients, who did not harbor RS, for mutations affecting three spliceosomal genes (SF3B1, U2AF1, and SRSF2). The mutation rates of SF3B1, U2AF1, and SRSF2 were 7.0 %, 7.8 %, and 10.1 %, respectively. Compared with previously reported results, these rates were relatively infrequent. The SRSF2 mutation strongly correlated with old age (P < 0.001), while the mutation status of SF3B1 did not affect overall survival (OS), progression-free survival (PFS), or acute myeloid leukemia (AML) transformation. In contrast, MDS patients with mutations in U2AF1 or SRSF2 exhibited inferior PFS. The U2AF1 mutation was associated with inferior OS in low-risk MDS patients (P = 0.035). The SRSF2 mutation was somewhat associated with AML transformation (P = 0.083). Our findings suggest that the frequencies of the SF3B1, U2AF1, and SRSF2 splicing gene mutations in MDS without RS were relatively low. We also demonstrated that the U2AF1 and SRSF2 mutations were associated with an unfavorable prognostic impact in MDS patients without RS.

Ju Hyeon Shin, M.D., Soo Hyun Kim, M.D., Dain Lee, M.S., Seung Yeob Lee, M.D., Sejong Chun, M.D., Jun Hyung Lee, M.D., Eun Jeong Won, M.D., Hyun Jung Choi, M.D., Hyun Woo Choi, M.D., Seung Jung Kee, M.D., Myung Geun Shin, M.D., and Jong Hee Shin, M.D.. Ann Lab Med 2021;41:214-20. https://doi.org/10.3343/alm.2021.41.2.214

Shinae Yu, M.D., Byung Ryul Jeon, M.D., Ph.D., Changseung Liu, M.D., Dokyun Kim, M.D., Ph.D., Hae-Il Park, M.D., Ph.D., Hyung Doo Park, M.D., Ph.D., Jeong Hwan Shin, M.D., Ph.D., Jun Hyung Lee, M.D., Ph.D., Qute Choi, M.D., Ph.D., Sollip Kim, M.D., Ph.D., Yeo Min Yun, M.D., Ph.D., and Eun-Jung Cho, M.D., Ph.D.; On behalf of the Evidence-Based Laboratory Medicine Committee of the Korean Society for Laboratory Medicine. Ann Lab Med -0001;0:. https://doi.org/10.3343/alm.2024.0111

Sung-Eun Cho, M.D., Jungsun Han, M.S., Juyoung You, M.S., Jun Hyung Lee, M.D., Ahram Yi, M.D., Sang Gon Lee, M.D., and Eun Hee Lee, M.D.. Ann Lab Med -0001;0:. https://doi.org/10.3343/alm.2024.0072

Mi Suk Park, Ph.D., Young Eun Lee, M.S., Hye Ran Kim, Ph.D., Jong Hee Shin, M.D., Ph.D., Hyun Wook Cho, Ph.D., Jun Hyung Lee, M.D., Ph.D., and Myung Geun Shin, M.D., Ph.D.. Ann Lab Med 2021;41:409-13. https://doi.org/10.3343/alm.2021.41.4.409