1.Research and development of genetic diagnostic method of Staphyloccocus aureus based on loop-mediated isothermal amplification
Haihua YI ; Guanghui HE ; Chao FANG ; Yangwei SONG ; Bo XU ; Huiyu SUN ; Yunfei WANG ; Wei WANG ; Zheng XU ; Jinwei ZHAO
Chinese Journal of Microbiology and Immunology 2010;30(4):382-386
Objective To develop a method of loop-mediated isothermal amplification(LAMP) to Staphyloccocus aureus rapidly, specifically, sensitively and simply suited for the primary health agency. Methods According to conserved nucleotide of Staphyloccocus aureus and principle of LAMP, we designed a set of LAMP primers and set up an LAMP reaction system. We evaluated the specificity, sensitivity and re-peatability of the method. In addition,we evaluated the linearity between initial template copies 1g value and reaction time (the time when the fluorescent value is 1×10~4). Results The optimal assay showed that it was no cross-reaction with other closely related members of pathogens, and was 10 times more sensitive than PCR. The coefficient of variance between tests was less than 5% ,and the kinetics curves showed a good line-arity between initial template copies lg value and reaction time(r~2=0. 9501). The detection activity could be finished within 1 h with the sensitivity of LAMP was 100% and the specificity was 94.4%, and the accuracy was 96.6%. Conclusion These findings demonstrated that the LAMP had the potential clinical application for detection and differentiation of Staphyloccocus aureus in the public health agency for its sensitive, specific and simple feature.
2.Clonal heterogeneity and its prognostic significance in acute lymphoblastic leukemia
Xiaodong LYU ; Zhen GUO ; Yangwei LI ; Jieying HU ; Ruihua FAN ; Yongping SONG
Chinese Journal of Internal Medicine 2020;59(8):629-633
Objective:To explore the characteristics and clinical significance of clonal heterogeneity in patients with acute lymphoblastic leukemia(ALL).Methods:From January 2016 to June 2019, 170 newly diagnosed ALL patients were enrolled in the Department of Hematology, Henan Cancer Hospital, including 93 males and 77 females, with a median age of 17 (2-80) years. Fifty-two ALL-related genes were detected by high-throughput sequencing technique. The clonal heterogeneity of mutations was analyzed according to the variant allele frequency (VAF) and the results of flow cytometry. The prognostic value of mutations was also evaluated.Results:Gene mutations were detected in 121 (71.2%, 121/170) patients, of which 2 or more clones were detected in 18 (52.9%, 18/34) T-cell acute lymphoblastic leukemia patients, while only 23 (16.9%, 23/136) B-cell acute lymphoblastic leukemia patients were positive of multiple mutations ( P<0.01).Gene mutation-related clonal heterogeneity analysis showed that 2 or more clones were frequent in patients with NOTCH1 mutations (13/19 patients) ( P<0.01). Event free survival (EFS) in patients with 3 or more clones was significantly lower than other patients (χ 2=10.330, P=0.016). Child ALL patients had similar result, that multiple clones predicted lower overall survival (OS) and EFS (OS: χ 2=7.974, P=0.047; EFS: χ 2=10.860, P=0.013). Conclusion:Clonal heterogeneity in ALL patients is closely related to the different origin of lymphocyte lineages and the age of onset, which may reveal the nature of the disease and predict the clinical outcome.
3. The genetic characteristics of BCR-ABL-negative myeloproliferative neoplasms
Xiaodong LYU ; Yangwei LI ; Zhen GUO ; Yaping XIN ; Jieying HU ; Ruihua FAN ; Yongping SONG
Chinese Journal of Internal Medicine 2020;59(1):35-39
Objective:
To explore the relationship between driver gene mutation (JAK2, MPL and CALR) and disease type in BCR-ABL negative myeloproliferative neoplasms (MPNs) including primary myeloid fibrosis (PMF), essential thrombocytosis (ET) and polycythemia vera (PV).
Methods:
A total of 32 MPN related genes were detected by high-throughput sequencing in 156 MPN patients. The relationships between disease type and patients′ general performance, the characteristics of driver gene mutations, concomitant gene mutations were analyzed.
Results:
In the population with JAK2 V617F positive mutation, the proportion of patients over 60 years old in PMF was higher than that with ET or PV. By high-throughput sequencing, 22 concomitant gene mutations were detected in 46 patients with JAK2, MPL or CALR mutations, including 4 (8.3%) in PV, 20 (29.4%) in ET, and 22 (55.0%) in PMF. DNMT3A mutation was detected only in patients with PV, while splicing factor related genes including SF3B1, SRSF2 and U2AF1 were only accompanied by PMF. According to the variation allele frequency (VAF) value of JAK2 V617F mutation, the VAF value associated with PV was the highest (68.15%), followed by PMF (37.7%) and ET (23%). However, there were significant differences in the incidence of JAK2 V617F homozygous among 3 different diseases. In patients with JAK2 mutation, the proportion of other gene mutations in PV and ET was significantly lower than that in PMF.
Conclusions
Under the condition of common driver gene mutations (JAK2, MPL and CALR), patients′ age, VAF value and homozygous state, concomitant gene mutations are closely related to different disease type. These correlations help to improve clinical understanding of disease characteristics and risk assessment.