Evaluation of the Z-score accuracy of noninvasive prenatal testing for fetal trisomies 13, 18 and 21 at a single center.

OBJECTIVE: To assess the correlation between Z-scores of positive noninvasive prenatal testing (NIPT) results and the positive predictive value (PPV) of NIPT. METHODS: Pregnancies with positive NIPT results at Guangzhou Women and Children's Medical Centre between July 2017 and May 2020 were included in this study. Fetal karyotyping or microarray analysis was provided to patients with abnormal NIPT results for confirmatory testing. Logistic regression analyses was applied to study the relationship between the Z scores and the PPV performance. The optimal cutoff values for indicating fetal common trisomies were obtained based on receiver operating characteristic (ROC) curve analysis, and then the PPV were calculated in pregnancies with positive NIPT results at Z-score greater than or equal to cutoff value and in patients with a Z-score between 3 and cutoff value respectively. RESULTS: A total of 214 pregnancies with positive NIPT results for fetal common trisomies were validated by invasive prenatal diagnosis and follow up in this study. Of these, NIPT indicated trisomy 13 in 25 cases, trisomy 18 in 54 cases and trisomy 21 in 135 patients. Logistic regression analyses showed a significant association (p < 0.05) between the Z-scores and true positive results for T21 and T18. For T13, the significant association was not observed (p > 0.05). The ROC curve analysis showed that the optimal cutoff Z-score for indicating fetal trisomies 13, 18, and 21 were 6.889, 7.574 and 6.612 respectively, and the corresponding area under curve were 0.706, 0.916, and 0.954. In this cohort with abnormal NIPT results, the cutoff values revealed a sensitivity of 96.8% and a specificity of 90% for indicating trisomies 21, and a sensitivity of 88.9% and a specificity of 92.6% for trisomies 18. However, probably due to the sample size, the sensitivity and specificity for indicating trisomy 13 were lower (85.7% and 61.1%) than that for trisomies 21 and 18. The PPVs in pregnancies with positive NIPT results at Z-score greater than or equal to cutoff value were 99.18% (121/122) for trisomy 21, 92.31% (24/26) for trisomy 18 and 46.15% (6/13) for trisomy 13. In patients with a Z-score between 3 and cutoff Z-score, the PPV of NIPT for trisomies 21, 18, and 13 were 30.77% (4/13), 10.71% (3/28), and 8.33% (1/12) respectively. Moreover, by classifying Z scores as 3 ≤ Z < 5, 5 ≤ Z < 10, and Z ≥ 10, the majority of Z scores were above 10 with a PPV of 99% for T21 and just 5.2% were between 3 and 5 with a PPV of 14.3%. In contrast for T18, over a third of tests had Z scores between 3 and 5. The PPV in this group is just over 5%. CONCLUSIONS: The present results show that the PPV performance of NIPT for fetal trisomies 13, 18, and 21 are closely associated with Z-score. The higher the Z-score, the greater the likelihood that the aneuploidy result is correct. Our experience in evaluating the Z-score accuracy of NIPT in this study could be of use in similar work.

Consistency between quantitative fluorescent-polymerase chain reaction and karyotyping in prenatal diagnosis / 中华围产医学杂志

Objective:To analyze the consistency between karyotyping and quantitative fluorescent- polymerase chain reaction (QF-PCR) in prenatal diagnosis.Methods:This study retrospectively analyzed the clinical data of 10 967 patients undergoing karyotyping and QF-PCR for prenatal diagnosis in Guangzhou Women and Children's Hospital from January 2010 to December 2017. The failure rate, results, and diagnosis of common chromosomal disorders of the two methods were compared. The sensitivity and specificity of QF-PCR in detecting chromosomal mosaicism were evaluated using the receiver operative characteristic (ROC) curve.Results:(1) The failure rates of karyotyping and QF-PCR were 0.99% (109/10 967) and 0.10% (11/10 967), respectively. (2) The karyotypes of 9 960 out of the 10 858 successfully cultured samples were normal, and 99.89% (9 949/9 960) results were consistent between the two methods. The other 898 cases included 694 (77.28%) with common chromosomal abnormalities (trisomy 21, 18 and 13 and sex chromosomal abnormality) and 204 (22.72%) with other chromosomal abnormalities. The consistency between the two methods in detecting common chromosomal abnormalities was 95.68% (664/694). (3) The consistency in the detection of trisomy 21, 18 and 13 and sex chromosomal abnormality between karyotyping and QF-PCR were 99.74% (382/383), 100.00% (125/125), 100.00% (33/33) and 81.05% (124/153). However, the common chromosomal mosaicism was only noted for 44.44% (24/54). (4) Among cases with a mosaic ratio over 18.5%, the sensitivity and specificity of QF-PCR were 0.958 (95% CI: 0.789-0.999) and 0.600 (95% CI: 0.406-0.773) with the area under the ROC curve (AUC) of 0.811 (95% CI: 0.696-0.926, P<0.001). (5) Thirty cases with negative QF-PCR results but positive mosaic chromosomal aberrations were followed up. Ten (33.3%) pregnant women terminated their pregnancies, and two (6.7%) were lost to follow-up. The other 18 cases delivered healthy neonates that all survived after birth. Conclusions:In prenatal diagnosis, QF-PCR and karyotyping were highly consistent in the detection of trisomy 21, 13, and 18, but have significant discordance in the diagnosis of sex chromosomal abnormality.

Improving the production of human placental chorionic-derived mesenchymal stem cells by modified primary culture method / 国际生物医学工程杂志

Objective To establish a cultivating method for obtaining a large number of P0 generation human placental chorionic-derived mesenchymal stem cells (hpcMSCs).Methods The hpcMSCs were isolated from human placental chorion.After primary culturing and culturing for seven days,the culture medium,the non-adherent tissue and the douching normal saline of the primary culture were centrifuged and re-cultured twice.Cell morphology was observed by an inverted microscope.CCK-8 was used to measure the cell growth curve.Flow cytometry was used to detect cell surface markers.Adipogenic and osteogenic differentiation kits were used to assess the cell differentiation potential.Results The obtained hpcMSCs were fibroblast-like adherent cells and (25.54±3.38)×106 cells were obtained per placenta.The total yield of the primary culture,secondary culture and tertiary culture were (11.73±2.09)×106,(11.12±1.42)×106 and (2.69±0.71)×106,respectively,and the incubation time were (12.00±0.64) d,(8.87±0.63) d and (12.33±0.80) d.There was significant differences in incubation time between the secondary culture and the primary culture as well as the tertiary culture (all P＜0.05),and there was no significant difference between the primary culture and the tertiary culture.However,the incubation time of the tertiary culture had an increasing trend (P＞0.05).The yield per culture flask of the primary culture,secondary culture and tertiary culture were (1.12±0.15) × 106,(2.10±0.16)×106 and (1.04±0.16)×106,respectively.There was significant differences in the yield per culture flask between the secondary culture and the primary culture as well as the tertiary culture (all P＜0.05),and there was no significant difference between the primary culture and the tertiary culture.However,the yield per culture flask of the tertiary culture had a decreasing trend (P＞0.05).There was no difference among the three cultures in the growth curve and the expression of surface markers,and the osteogenic and adipogenic differentiation were all positive.Conclusions The P0 generation hpcMSCs isolated from a choriocarcinoma sample can be doubled by the three cultures compared with the primary culture,which can provide plenty stem cell source for the regenerative medicine.

Isolation and cultivation of human placental chorionic-derived mesenchymal stem cells: optimization of the tissue explants method / 中国组织工程研究

BACKGROUND:There are a lot of studies on isolation and culture methods of human placental chorionic-derived mesenchymal stem cells (hpcMSCs), but how to simply and efficiently harvest a large amount of primary MSCs has not been resolved. OBJECTIVE:To optimize the tissue explants method of isolating and culturing hpcMSCsin vitro. METHODS:Human placental chorionic villi were collected from full-term deliveries under aseptic condition and isolated by electric homogenizer. hpcMSCs were prepared by tissue explants method. The fluid and tissue of the primary culture flask and douching normal saline of the initial culture were centrifuged and prepared for secondary culture. RESULTS AND CONCLUSION: It saved time and effort to treat human placental chorionic villi with electric homogenizer, with good effects on tissue dispersion and removal of red blood cells. The average time of cell acquisition in initial culture and secondary culture was (17.73±1.14) and (10.03±1.30) days, respectively. The yields of primary cultured cells in initial culture and secondary culture were (6.97±0.98)×105 and (13.82±1.44)×105per Φ100 mm culture dish, respectively. The adherent cells showed fibroblast-cell-like shape, which were in parallel or circinate arrangement. Highly expressed CD73, CD105 and CD90 could be detected in the third generation of hpcMSCs, but CD34, CD45, CD14, CD19 and HLA-DR were negative. Following induction, alizarin red staining and oil red O staining produced a strong reaction in cells. In a word, the optimized method is a simple and efficient method for obtaining a large amount of primary hpcMSCs.

Deep sequencing of the T cell receptor Vb CDR3 repertoire of peripheral CD4+T cells in primary biliary cirrhosis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To determine the immune repertoires of peripheral CD4+T cell receptor (TCR) Vb CDR3 in primary biliary cirrhosis (PBC) and analyze TCR diversity and preferred usage at sequence-level resolution.</p><p><b>METHODS</b>ARM-PCR and high-throughput sequencing were used to obtain millions of TCR Vb CDR3 sequences from peripheral CD4+T cells isolated from 7 patients with PBC and healthy volunteers. All sequencing data were analyzed, together with corresponding clinical information, by bioinformatic software. The Mann-Whitney U test was used for statistical analysis.</p><p><b>RESULTS</b>The PBC patients showed a lower level of diversity among the peripheral CD4+TCR Vb CDR3 than the healthy volunteers, and patients with higher level progression of the disease showed a greater lack of diversity. In addition, 4 specific preferred-usage amino acid sequences were discovered for the PBC patients: ASSFTGGPVEQY, ASSLISSGNNEQF, ATSRDTLAGGPGDTQY, and SASLEGNTEAF; these sequences were also found in higher frequencies in patients with later stages of PBC.</p><p><b>CONCLUSIONS</b>Decreased TCR Vb CDR3 diversities and specific preferred usage of TCR CDR3 sequences in peripheral CD4+T lymphocytes in PBC suggest that clonal expansion of a large number of CD4+T cells may be an important factor for PBC progression. These data provide a better understanding about the general characteristics of CD4+T cells in PBC patients and related to pathogenesis of the disease, and may provide useful insights into potential targets for immunotherapy.</p>

Quantitative fluorescent-polymerase chain reaction for rapid prenatal diagnosis of common aneuploidies / 中华围产医学杂志

Objective To evaluate the clinical value of quantitative fluorescent polymerase chain reaction (QF-PCR) in rapid prenatal diagnosis of aneuploidies. Methods Twenty-two short tandem repeats (STR) and AMXY located on chromosome 13,18,21,X and Y were used as markers to examine 1740 samples from high risk pregnant women in Down syndrome screening and advanced maternal age(≥35 yrs) by QF-PCR.Samples were also tested by karyotype analysis and the results of the two methods were compared. Results Karyotype analysis and QF-PCR results were successfully obtained from 1690 samples. All QF-PCR reports were obtained within 48 hours after sample collection.For 1639 samples,normal results were obtained by both karyotype analysis and QF-PCR.Among 51 samples that were found abnormal by karyotype analysis,41 were abnormal in QF-PCR.The rapid tests found all numerical abnormalities involving chromosome 21,18,13,X and Y in prenatal diagnosis,including trisomy 21 (n =30),trisomy 18 (n =6),45,XO (n =1 ),47,XYY (n=1),47,XXX (n=1),69,XXX (n=1) and mosaic 47,XXY[94]/46,XX[6] (n=1)(47,XXY in QF-PCR).No false positive results were found.The results obtained by QF-PCR were consistent with those of cytogenetic studies in 99.4％ of the samples (1680/1690).Only ten cases of mosain and structural abnormality could not be found (0.6％,10/1690) by QF-PCR. Conclusions Rapid QF-PCR test might diagnose all aneuploidies involving chromosome 21,18,13,X and Y.It could provide rapid and accurate diagnosis for 99.4％ pregnant women with positive Down syndrome screening and advanced maternal age.