Can Face- and Smartphone-Touching Behaviors Be Altered with Personal Hygiene Reminders during the COVID-19 Pandemic Period? An Observational Study

As part of the new measures to prevent the spread of the 2019 coronavirus disease (COVID-19), medical students were advised to wear a mask in class and avoid touching their faces. Few studies have analyzed the influence of health education on the frequency of face- and smartphone-touching behaviors during the COVID-19 pandemic. This research compared the frequency of in-class face- and smartphone-touching behaviors of medical students before and after the delivery of personal hygiene education during the COVID-19 pandemic. A behavioral observational study was conducted involving medical students at Taipei Medical University. Eighty medical students were recruited during a lecture on otorhinolaryngology. All medical students were required to wear a mask. Their face- and smartphone-touching behavior was observed by viewing the 4 k resolution video tape recorded in class. The recording lasted for 2 h, comprising 1 h prior to the health educational reminder and 1 h afterwards. The frequencies of hand-to-face contact and hand-to-smartphone contact were analyzed before and after the delivery of health education emphasizing personal hygiene. Comprehensive health education and reminders effectively reduce the rate of face- and smartphone-touching behaviors.

Empirical assessment of biases in cerebrospinal fluid biomarkers of Alzheimer's disease: an umbrella review and re-analysis of data from meta-analyses

OBJECTIVE

Alzheimer's disease (AD) is a leading cause of years lived with disability in older age, and several cerebrospinal fluid (CSF) markers have been proposed in individual meta-analyses to be associated with AD but field-wide evaluation and scrutiny of the literature is not available.

MATERIALS AND METHODS

We performed an umbrella review for the reported associations between CSF biomarkers and AD. Data from available meta-analyses were reanalyzed using both random and fixed effects models. We also estimated between-study heterogeneity, small-study effects, excess significance, and prediction interval.

RESULTS

A total of 38 meta-analyses on CSF markers from 11 eligible articles were identified and reanalyzed. In 14 (36%) of the meta-analyses, the summary estimate and the results of the largest study showed non-concordant results in terms of statistical significance. Large heterogeneity (I2≥75%) was observed in 73% and small-study effects under Egger's test were shown in 28% of CSF biomarkers.

CONCLUSIONS

Our results suggest that there is an excess of statistically significant results and significant biases in the literature of CSF biomarkers for AD. Therefore, the results of CSF biomarkers should be interpreted with caution.

Ugonin J Acts as a SARS-CoV-2 3C-like Protease Inhibitor and Exhibits Anti-inflammatory Properties

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes severe “flu-like” symptoms that can progress to acute respiratory distress syndrome (ARDS), pneumonia, renal failure, and death. From the therapeutic perspective, 3-chymotrypsin-like protein (3CLpro) is a plausible target for direct-acting antiviral agents because of its indispensable role in viral replication. The flavonoid ugonin J (UJ) has been reported to have antioxidative and anti-inflammatory activities. However, the potential of UJ as an antiviral agent remains unexplored. In this study, we investigated the therapeutic activity of UJ against SARS-CoV-2 infection. Importantly, UJ has a distinct inhibitory activity against SARS-CoV-2 3CLpro, compared to luteolin, kaempferol, and isokaempferide. Specifically, UJ blocks the active site of SARS-CoV-2 3CLpro by forming hydrogen bonding and van der Waals interactions with H163, M165 and E166, G143 and C145, Q189, and P168 in subsites S1, S1′, S2, and S4, respectively. In addition, UJ forms strong, stable interactions with core pharmacophore anchors of SARS-CoV-2 3CLpro in a computational model. UJ shows consistent anti-inflammatory activity in inflamed human alveolar basal epithelial A549 cells. Furthermore, UJ has a 50% cytotoxic concentration (CC₅₀) and a 50% effective concentration (EC₅₀₎ values of about 783 and 2.38 µM, respectively, with a selectivity index (SI) value of 329, in SARS-CoV-2-infected Vero E6 cells. Taken together, UJ is a direct-acting antiviral that obstructs the activity of a fundamental protease of SARS-CoV-2, offering the therapeutic potential for SARS-CoV-2 infection.

[Association of maternal anxiety with congenital heart disease in offspring based on case-control study]

Objective: To explore the association of maternal anxiety with congenital heart disease (CHD) in offspring. Methods: A case-control study design was used in this study. The data were collected in Shaanxi province from January 2014 to December 2016. Neonatal information is provided through specialized hospitals or institutions. Logistic regression model with adjustment for confounding factors was established to analyze the association between maternal perinatal anxiety and CHD in offspring. Meanwhile, subgroup analysis was carried out to explore its stability. Results: Our study included 2 429 subjects, consisting of 773 cases and 1 656 controls. Women with anxiety during pregnancy accounted for 10.3% in the case group, while 7.8% in the control group. After adjusting for confounding factors, the level of maternal anxiety during pregnancy was positively correlated with CHD in the offspring (OR=1.04, 95%CI: 1.01-1.07). The risk of CHD in the offspring of mothers with anxiety during pregnancy was 1.43 times higher than that in those whose mothers had no anxiety (OR=1.43, 95%CI: 1.00-2.05). Conclusion: Maternal anxiety during pregnancy is probably a risk factor for congenital heart disease in offspring.

Body mass index and mortality in patients with cardiovascular disease: an umbrella review of meta-analyses

OBJECTIVE

Although many previous meta-analyses of epidemiological studies have demonstrated a relationship between body mass index (BMI) and mortality, inconsistent findings among cardiovascular disease patients have been observed. Thus, we performed an umbrella review to understand the strength of evidence and validity of claimed associations between BMI and mortality in patients with cardiovascular diseases.

MATERIALS AND METHODS

We comprehensively re-analyzed the data of meta-analyses of observational studies and randomized controlled trials on associations between BMI and mortality among patients with cardiovascular diseases. We also assessed the strength of evidence of the re-analyzed outcomes, which were determined from the criteria including statistical significance of the p-value of random-effects, as well as fixed-effects meta-analyses, small-study effects, between-study heterogeneity, and a 95% prediction interval.

RESULTS

We ran comprehensive re-analysis of the data from the 21 selected studies, which contained a total of 108 meta-analyses; 23 were graded as convincing evidence and 12 were suggestive, 42 were weak, and 23 were non-significant.

CONCLUSIONS

Underweight increased mortality in acute coronary syndrome (ACS), heart failure, and after therapeutic intervention for patients with cardiovascular diseases. Overweight, on the other hand decreased mortality in patient's ACS, atrial fibrillation, and heart failure with convincing evidence.

[Consistency of peripheral whole blood and venous serum procalcitonin in children: a multicenter parallel controlled study]

Objective: To explore the consistency of peripheral whole blood and venous serum procalcitonin (PCT) levels, and the value of peripheral whole blood PCT in evaluating pediatric bacterial infection. Methods: This multicenter cross-sectional parallel control study was conducted in 11 children's hospital. All the 1 898 patients older than 28 days admitted to these hospitals from March 2018 to February 2019 had their peripheral whole blood and venous serum PCT detected simultaneously with unified equipment, reagent and method. According to the venous serum PCT level, the patients were stratified to subgroups. Analysis of variance and chi-square test were used to compare the demographic characteristics among groups. And the correlation between the peripheral blood and venous serum PCT level was investigated by quantitative Pearson correlation analysis.The PCT resultes were also converted into ranked data to further test the consistency between the two sampling methods by Spearman's rank correlation test. Furthermore, the ranked data were converted into binary data to evaluate the consistency and investigate the best cut-off of peripheral blood PCT level in predicting bacterial infection. Results: A total of 1 898 valid samples were included (1 098 males, 800 females),age 27.4(12.2,56.7) months. There was a good correlation between PCT values of peripheral whole blood and venous serum (r=0.97, P<0.01). The linear regression equation was PCT_{venous serum}=0.135+0.929×PCT_{peripheral whole blood}. However, when stratified to 5 levels, PCT results showed diverse and unsatisfied consistency between the two sampling methods (r=0.51-0.92, all P<0.01). But after PCT was converted to ordinal categorical variables, the stratified analysis showed that the coincidence rate of the measured values by the two sampling methods in each boundary area was 84.9%-97.1%. The dichotomous variables also showed a good consistency (coincidence rate 96.8%-99.3%, Youden index 0.82-0.89). According to the severity of disease, the serum PCT value was classified into 4 intervals（<0.5、0.5-<2.0、2.0-<10.0、≥10.0 μg/L）, and the peripheral blood PCT value also showed a good predictive value (AUC value was 0.991 2-0.997 9). The optimal cut points of peripheral whole blood PCT value 0.5、1.0、2.0、10.0 μg/L corresponding to venous serum PCT values were 0.395, 0.595, 1.175 and 3.545 μg/L, respectively. Conclusions: There is a good correlation between peripheral whole blood PCT value and the venous serum PCT value, which means that the peripheral whole blood PCT could facilitate the identification of infection and clinical severity. Besides, the sampling of peripheral whole blood is simple and easy to repeat.

Pharmacophore anchor models of ATAT1 to discover potential inhibitors and lead optimization

Post-translation modification of microtubules is associated with many diseases like cancer. Alpha Tubulin Acetyltransferase 1 (ATAT1) is a major enzyme that acetylates 'Lys-40' in alpha-tubulin on the luminal side of microtubules and is a drug target that lacks inhibitors. Here, we developed pharmacophore anchor models of ATAT1 which were constructed statistically using thousands of docked compounds, for drug design and investigating binding mechanisms. Our models infer the compound moiety preferences with the physico-chemical properties for the ATAT1 binding site. The results from the pharmacophore anchor models show the three main sub-pockets, including S1 acetyl site, S2 adenine site, and S3 diphosphate site with anchors, where conserved moieties interact with respective sub-pocket residues in each site and help in guiding inhibitor discovery. We validated these key anchors by analyzing 162 homologous protein sequences (>99 species) and over 10 structures with various bound ligands and mutations. Our results were consistent with previous works also providing new interesting insights. Our models applied in virtual screening predicted several ATAT1 potential inhibitors. We believe that our model is useful for future inhibitor discovery and for guiding lead optimization.

An integrated systematic approach for investigating microcurrent electrical nerve stimulation (MENS) efficacy in STZ-induced diabetes mellitus

Diabetes mellitus (DM) is a major metabolic disorder and an increasing health problem worldwide. Effective non-invasive therapies for DM are still lacking. Here, we have developed Microcurrent electrical nerve stimulation (MENS), a non-invasive therapy, and tested on 46 mice clustered into five groups, such as control, STZ-induced DM, and MENS treatment groups. Experimental results show that MENS treatment is able to improve seven biochemical indexes (e.g., hemoglobin A1c and glucose level). To investigate the mechanisms of MENS treatment on STZ-induced DM, we selected six representative samples to perform microarray experiments for several groups and developed an integrated Hierarchical System Biology Model (HiSBiM) to analyze these omics data. The results indicate that MENS can affect fatty acid metabolism pathways, peroxisome proliferator-activated receptor (PPAR) signaling pathway and cell cycle. Additionally, the DM biochemical indexes and omics data profiles of MENS treatment were found to be consistent. We then compared the therapeutic effects of MENS with anti-diabetic compounds (e.g., quercetin, metformin, and rosiglitazone), using the HiSBiM four-level biological functions and processes of multiple omics data. The results show MENS and these anti-diabetic compounds have similar effect pathways highly correlated to the diabetes processes, such as the PPAR signaling pathway, bile secretion, and insulin signaling pathways. We believe that MENS is an effective and non-invasive therapy for DM and our HiSBiM is an useful method for investigating multiple omics data.

CoMI: consensus mutual information for tissue-specific gene signatures

Background

The gene signatures have been considered as a promising early diagnosis and prognostic analysis to identify disease subtypes and to determine subsequent treatments. Tissue-specific gene signatures of a specific disease are an emergency requirement for precision medicine to improve the accuracy and reduce the side effects. Currently, many approaches have been proposed for identifying gene signatures for diagnosis and prognostic. However, they often lack of tissue-specific gene signatures.

Results

Here, we propose a new method, consensus mutual information (CoMI) for analyzing omics data and discovering gene signatures. CoMI can identify differentially expressed genes in multiple cancer omics data for reflecting both cancer-related and tissue-specific signatures, such as Cell growth and death in multiple cancers, Xenobiotics biodegradation and metabolism in LIHC, and Nervous system in GBM. Our method identified 50-gene signatures effectively distinguishing the GBM patients into high- and low-risk groups (log-rank p = 0.006) for diagnosis and prognosis.

Conclusions

Our results demonstrate that CoMI can identify significant and consistent gene signatures with tissue-specific properties and can predict clinical outcomes for interested diseases. We believe that CoMI is useful for analyzing omics data and discovering gene signatures of diseases.

Uncovering Flexible Active Site Conformations of SARS-CoV-2 3CL Proteases through Protease Pharmacophore Clusters and COVID-19 Drug Repurposing

The infectious SARS-CoV-2 causes COVID-19, which is now a global pandemic. Aiming for effective treatments, we focused on the key drug target, the viral 3C-like (3CL) protease. We modeled a big dataset with 42 SARS-CoV-2 3CL protease-ligand complex structures from ∼98.7% similar SARS-CoV 3CL protease with abundant complex structures. The diverse flexible active site conformations identified in the dataset were clustered into six protease pharmacophore clusters (PPCs). For the PPCs with distinct flexible protease active sites and diverse interaction environments, we identified pharmacophore anchor hotspots. A total of 11 "PPC consensus anchors" (a distinct set observed in each PPC) were observed, of which three "PPC core anchors" EHV2, HV1, and V3 are strongly conserved across PPCs. The six PPC cavities were then applied in virtual screening of 2122 FDA drugs for repurposing, using core anchor-derived "PPC scoring S" to yield seven drug candidates. Experimental testing by SARS-CoV-2 3CL protease inhibition assay and antiviral cytopathic effect assays discovered active hits, Boceprevir and Telaprevir (HCV drugs) and Nelfinavir (HIV drug). Specifically, Boceprevir showed strong protease inhibition with micromolar IC₅₀ of 1.42 μM and an antiviral activity with EC₅₀ of 49.89 μM, whereas Telaprevir showed moderate protease inhibition only with an IC₅₀ of 11.47 μM. Nelfinavir solely showed antiviral activity with a micromolar EC₅₀ value of 3.28 μM. Analysis of binding mechanisms of protease inhibitors revealed the role of PPC core anchors. Our PPCs revealed the flexible protease active site conformations, which successfully enabled drug repurposing.

The inhibitory effects of PGG and EGCG against the SARS-CoV-2 3C-like protease

The coronavirus disease (COVID-19) pandemic, resulting from human-to-human transmission of a novel severe acute respiratory syndrome coronavirus (SARS-CoV-2), has led to a global health crisis. Given that the 3 chymotrypsin-like protease (3CLpro) of SARS-CoV-2 plays an indispensable role in viral polyprotein processing, its successful inhibition halts viral replication and thus constrains virus spread. Therefore, developing an effective SARS-CoV-2 3CLpro inhibitor to treat COVID-19 is imperative. A fluorescence resonance energy transfer (FRET)-based method was used to assess the proteolytic activity of SARS-CoV-2 3CLpro using intramolecularly quenched fluorogenic peptide substrates corresponding to the cleavage sequence of SARS-CoV-2 3CLpro. Molecular modeling with GEMDOCK was used to simulate the molecular interactions between drugs and the binding pocket of SARS-CoV-2 3CLpro. This study revealed that the V_max of SARS-CoV-2 3CLpro was about 2-fold higher than that of SARS-CoV 3CLpro. Interestingly, the proteolytic activity of SARS-CoV-2 3CLpro is slightly more efficient than that of SARS-CoV 3CLpro. Meanwhile, natural compounds PGG and EGCG showed remarkable inhibitory activity against SARS-CoV-2 3CLpro than against SARS-CoV 3CLpro. In molecular docking, PGG and EGCG strongly interacted with the substrate binding pocket of SARS-CoV-2 3CLpro, forming hydrogen bonds with multiple residues, including the catalytic residues C145 and H41. The activities of PGG and EGCG against SARS-CoV-2 3CLpro demonstrate their inhibition of viral protease activity and highlight their therapeutic potentials for treating SARS-CoV-2 infection.

[Research progress of curcumin in the prevention and treatment of periodontitis]

Curcumin is a plant-derived polyphenol extracted from the rhizome of turmeric. As curcumin has such favorable properties as anti-inflammation, anti-oxidation, anti-angiogenesis, immune regulation, anti-bacterial and pro-apoptosis and showed few side effects, the application of curcumin in prevention and treatment of periodontal diseases is promising. This article reviewed the research progress of curcumin in the prevention and treatment of periodontitis.

[Clinical characteristics and survival analysis of 15 cases of HIV-negative plasmablastic lymphoma]

目的

分析HIV阴性的浆母细胞淋巴瘤（PBL）患者的临床病理特征及转归。

方法

回顾性分析海军军医大学附属长海医院2013年1月至2019年8月诊断及治疗的15例HIV阴性PBL患者的临床病理资料及随访结果。

结果

15例HIV阴性PBL患者中男8例，女7例，中位年龄59（17~69）岁，均无明确的免疫抑制状态。所有患者均出现结外受累，Ann Arbor-Cotswolds分期Ⅰ、Ⅱ、Ⅲ、Ⅳ期分别为1例（6.7%）、2例（13.3%）、3例（20.0%）、9例（60.0%）。病理形态表现为类似免疫母细胞的大肿瘤细胞弥漫性增生，免疫组化示肿瘤细胞主要表达浆细胞标志CD38、CD138、Mum-1，B细胞标志CD20、CD10、PAX-5、BCL-6少见，Ki-67中位数为80%（70%~90%）。3例患者行EBER原位杂交检测，1例阳性。15例患者均接受化疗，80%（12/15）联合硼替佐米作为一线治疗。最佳疗效6例完全缓解（其中2例分别于治疗后4.9和26.1个月疾病进展），2例部分缓解（分别于治疗后3.0和6.8个月疾病进展），4例疾病进展，3例无法评估。中位随访时间30.3（4.8~61.1）个月，11例患者中位无进展生存（PFS）期6.8（95%CI 2.5~11.1）个月，预计3年PFS率为21.2%（95%CI 1.4%~56.8%）。所有患者中位总生存（OS）期为17.9（95%CI 5.6~30.2）个月，预计3年OS率为38.5%（95%CI 12.0%~65.0%）。

结论

HIV阴性PBL侵袭性强，结外受累常见，多数患者诊断时分期较晚。通过以硼替佐米为基础的强化疗方案序贯自体造血干细胞移植可望获得长期生存。

Zika Virus NS3 Protease Pharmacophore Anchor Model and Drug Discovery

Zika virus (ZIKV) of the flaviviridae family, is the cause of emerging infections characterized by fever, Guillain-Barré syndrome (GBS) in adults and microcephaly in newborns. There exists an urgent unmet clinical need for anti-ZIKV drugs for the treatment of infected individuals. In the current work, we aimed at the promising virus drug target, ZIKV NS3 protease and constructed a Pharmacophore Anchor (PA) model for the active site. The PA model reveals a total of 12 anchors (E, H, V) mapped across the active site subpockets. We further identified five of these anchors to be critical core anchors (CEH1, CH3, CH7, CV1, CV3) conserved across flaviviral proteases. The ZIKV protease PA model was then applied in anchor-enhanced virtual screening yielding 14 potential antiviral candidates, which were tested by in vitro assays. We discovered FDA drugs Asunaprevir and Simeprevir to have potent anti-ZIKV activities with EC₅₀ values 4.7 µM and 0.4 µM, inhibiting the viral protease with IC₅₀ values 6.0 µM and 2.6 µM respectively. Additionally, the PA model anchors aided in the exploration of inhibitor binding mechanisms. In conclusion, our PA model serves as a promising guide map for ZIKV protease targeted drug discovery and the identified ‘previr’ FDA drugs are promising for anti-ZIKV treatments.

[Inhibitors of RAS Might Be a Good Choice for the Therapy of COVID-19 Pneumonia]

The novel coronavirus 2019 (COVID-19) infected patients by binding human ACE2, leading to severe pneumonia and highly mortality rate in patients. At present, there is no definite and effective treatment for COVID-19. ACE2 plays an important role in the RAS, and the imbalance between ACE/Ang II/AT1R pathway and ACE2/Ang (1-7)/Mas receptor pathway in the RAS system will lead to multi-system inflammation. Increased ACE and Ang II are poor prognostic factors for severe pneumonia. Animal studies have shown that RAS inhibitors could effectively relieve symptoms of acute severe pneumonia and respiratory failure. The binding of COVID-19 and ACE2 resulted in the exhaustion of ACE2, and then ACE2/Ang (1-7)/Mas receptor pathway was inhibited. The balance of the RAS system was broken, and this would lead to the exacerbation of acute severe pneumonia. Therefore, we speculate that ACEI and AT1R inhibitors could be used in patients with COVID-19 pneumonia under the condition of controlling blood pressure, and might reduce the pulmonary inflammatory response and mortality.

[Inhibitors of RAS Might Be a Good Choice for the Therapy of COVID-19 Pneumonia]

The novel coronavirus 2019 (COVID-19) infected patients by binding human ACE2, leading to severe pneumonia and highly mortality rate in patients. At present, there is no definite and effective treatment for COVID-19. ACE2 plays an important role in the RAS, and the imbalance between ACE/Ang II/AT1R pathway and ACE2/Ang (1-7)/Mas receptor pathway in the RAS system will lead to multi-system inflammation. Increased ACE and Ang II are poor prognostic factors for severe pneumonia. Animal studies have shown that RAS inhibitors could effectively relieve symptoms of acute severe pneumonia and respiratory failure. The binding of COVID-19 and ACE2 resulted in the exhaustion of ACE2, and then ACE2/Ang (1-7)/Mas receptor pathway was inhibited. The balance of the RAS system was broken, and this would lead to the exacerbation of acute severe pneumonia. Therefore, we speculate that ACEI and AT1R inhibitors could be used in patients with COVID-19 pneumonia under the condition of controlling blood pressure, and might reduce the pulmonary inflammatory response and mortality.

[Effect of consolidation before allogeneic hematopoietic stem cell transplantation for non-favorable acute myeloid leukemia patients with first complete remisson and negative minimal residual disease]

目的

探讨异基因造血干细胞移植（allo-HSCT）前巩固化疗对第1次形态学完全缓解且微小残留病阴性（CR₁/MRD⁻）中/高危急性髓系白血病（AML）患者预后的影响。

方法

对2010年1月至2019年3月在CR₁/MRD⁻状态下接受allo-HSCT的155例中/高危AML（不含急性早幼粒细胞白血病）患者进行回顾性分析。

结果

全部155例患者中，102例获得CR₁/MRD⁻后接受移植前巩固化疗（巩固组），53例获得CR₁/MRD⁻后直接行allo-HSCT（非巩固组），两组中位年龄分别为39（18~56）岁、38（19~67）岁。巩固组、非巩固组移植后5年总生存率分别为（59.3±7.5）%、（62.2±6.9）%（P=0.919），无复发生存率分别为（53.0±8.9）%、（61.6±7.0）%（P=0.936），累积复发率分别为（21.9±5.4）%、（18.3±6.0）%（P=0.942），非复发死亡率分别为（22.4±4.3）%、（28.4±6.5）%（P=0.464）。多因素分析显示，移植前是否接受巩固化疗及其疗程（<2个/≥2个）对预后无显著影响。

结论

中/高危AML患者可在获得CR₁/MRD⁻后直接进行allo-HSCT。

[Prognostic value of donor chimerism at +90 days after allogeneic hematopoietic stem cell transplantation in young patients with intermediate-risk acute myeloid leukemia]

Objective: To investigate the relationship between donor chimerism and relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: The clinical data of 105 patients with acute myeloid leukemia (AML) who underwent allo-HSCT and recurrence-free survival>90 days from January 2010 to January 2019 were retrospectively analyzed. The bone marrow samples were collected at 15, 30, 60, 90, 180, 270, 360 days after transplantation. Donor chimerism was detected by single nucleotide polymorphism (SNP) -PCR. Results: Of the 105 patients, 43 cases were male and 62 cases were female, with a median age of 38 (16-60) years. Till April 2019, the median follow-up was 843 (94-3 261) days. Ninety days after transplantation, 18 cases relapsed, 33 cases died, and 72 cases survived. The 3-year overall survival (OS) rate was (66.8±5.1) %, and the recurrence-free survival (RFS) rate was (65.1±5.0) %. Pre-transplant disease status, pre-transplant minimal residual disease (MRD) , and 90 day post-transplantation chimerism were independent risk factors related to RFS. The risk of recurrence was significantly increased in patients with a donor chimerism rate ≤97.24% at 90 days after transplantation[HR=6.921 (95%CI 2.669-17.950) , P<0.001], which was considered as a sign of early relapse. Conclusion: SNP-PCR is an applicable method for detecting donor chimerism in patients after allo-HSCT. Chimerism rate equal or less than 97.24% at 90 days after transplantation predicts a higher risk of relapse.