Adding acupoint identification into the textbook Meridians and Acupoints: preliminary assumption / 中国针灸

To deepen the understanding of the acupoint indications, clarify the targeting of acupoints, and provide a basis for the composition of acupuncture prescriptions, it is suggested to add acupoint identification into the textbook Meridians and Acupoints, and a preliminary assumption that relevant acupoints can be identified by taking the indications, locations, and meridians as the key points is proposed. In this paper, acupoints for treating stomach disease, acupoints of eye region, and five-shu points of lung meridian are taken as examples, combined with ancient literature and modern scientific research achievements, the main indications of acupoint is identified, which is of great significance to the discipline's development, talent training, and achievement transformation.

Causes and Countermeasures of Complications After Bariatric Surgery / 中国医学科学院学报

Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy characterized by simple operation and few postoperative complications have gradually become the two most commonly used surgical methods in clinical practice.A series of complications often occur after bariatric surgery,including gallstone disease,anemia,malnutrition,gastroesophageal reflux disease,kidney stones,and birth defects in offspring of women of childbearing age.There are controversies regarding the causes and countermeasures of these complications.This article mainly reviews the risk factors and countermeasures for the complications after bariatric surgery.

Treatment of pyogenic granuloma in children with a 595 nm pulsed dye laser: A retrospective study of 212 patients.

BACKGROUND: Pyogenic granuloma (PG) is a common vascular neoplasm in children. Data on 595 nm pulsed dye lasers for the treatment of PG in children remain scarce. OBJECTIVE: To summarize the clinical characteristics and to evaluate the effectiveness and safety of the 595 nm pulsed dye laser for the treatment of PG in children. STUDY DESIGN: Retrospective case series. METHODS: A retrospective study was performed on 212 patients treated for PG with a 595 nm pulsed dye laser. SPSS version 19.0 was used for statistical analysis. RESULTS: Among all 212 patients treated, 208 showed complete resolution of the lesion, and 4 dropped out after one treatment due to bleeding. A single treatment was sufficient in 139 (66.8%) patients, while two or three treatments were sufficient in 69 (33.2%) patients. Male patients responded better than female patients (χ2 = 7.603, p =0.006). Lesions in the nonorbital region responded better than those in the orbital region (χ2 = 7.445, p =0.006). The size of the lesion affected the effectiveness, and lesions with smaller diameters (t = -5.776, p <0.01) and heights (t = -10.368, p <0.01) showed better results. COMPLICATIONS AND SIDE EFFECTS: Twelve patients (5.8%) were reported to have local complications and side effects, including edematous erythema, slight bleeding, hyperpigmentation, and hypopigmentation. The edematous erythema and slight bleeding disappeared gradually after several days. The localized pigment changes usually resolved spontaneously and disappeared completely after 6 months. CONCLUSIONS: Our experience confirmed the efficacy and safety of the 595 nm pulsed dye laser for the treatment of PG in children.

Research progress on the regulation and mechanism of reactive oxygen species on tumor immune checkpoints / 药学学报

Immune checkpoints (ICs) are immunosuppressive molecules expressed on immune cells, which can regulate immune cells' activation. Immune checkpoint inhibitors (ICIs) which can block the interaction of immune checkpoints and their ligands, improve the cytotoxic effect of the immune system on tumor cells. Immunotherapy such as employing ICIs has gradually become a conventional therapeutic strategy for cancer treatment. However, the low response rate and the emergence of drug resistance have seriously affected the clinical efficacy of ICIs. Reactive oxygen species (ROS) are electronic reduction products of active oxygen, as well as natural by-products of cell metabolism, which can be used as regulators of intercellular signals. Tumor microenvironment (TME) is often in the state of oxidative stress (OS), which is the imbalance between oxidative system and antioxidant system. ROS can affect the interaction with its ligands by regulating the expression and activity of immune checkpoints in TME, thus affecting the anti-tumor effect of immune cells. Accumulating studies have shown that ROS could regulate tumor immune checkpoints through several pathways. Due to different types and stages of tumor, it would be clinical beneficial to understand the mechanistic link of ROS on tumor immune checkpoint, and choose appropriate ROS regulators combined with immune checkpoint inhibitors to maximize anti-tumor effects. This article reviews the common metabolic sources and characteristics of ROS, the regulatory effect and mechanism of ROS on tumor immune checkpoints and its therapeutic application.

Relationship between the Expression of miRNA181a-5p and the Imbalance of Treg/Th17 in Primary Immune Thrombocytopenia / 中国实验血液学杂志

OBJECTIVE@#To investigate the role of relationship between the expression of miRNA181a-5p and imbalance of Treg/Th17 in the pathogenesis of primary immune thrombocytopenia(ITP), which contributes to clarify the mechanism of T cell immune imbalance in ITP patients.@*METHODS@#Peripheral blood was collected from 37 ITP patients, concluding 21 untreated patients and 16 effectively treated patients, and 19 healthy controls; Peripheral blood mononuclear cells (PBMC) were isolated and the expression of miRNA181a-5p and Notch1 was analyzed by RT-PCR. The proportion of Th17 subsets and Treg cells in the peripheral circulation was detected by flow cytometer (FCM). Clinical data of ITP group was collected, including age, platelet count and disease course.@*RESULTS@#The expression of miR-181a-5p was significantly decreased in ITP group than that of healthy control group (P＜0.01). After effective treatment, the expression of miR-181a-5p was significantly higher than that of ITP group (P＜0.05), but still significantly lower than that of healthy control group (P＜0.01); The expression of Notch1 was significantly increased in ITP group and effectively treated group than that of healthy control group (P＜0.01). There was no significant difference in proportion of Treg cells in ITP group, effectively treated group and healthy control group (P＞0.05). The proportion of Th17 subsets in ITP group was significantly increased than that of healthy control group (P＜0.05), while the ratio of Treg/Th17 was significantly decreased (P＜0.05). There was a positive correlation between the expression of miR-181a-5p and ratio of Treg/Th17 in ITP group (r=0.555).@*CONCLUSION@#The expression of miR-181a-5p is significantly decreased in ITP patients, which is closely related to the imbalance of Treg/Th17 cells. After effective treatment, the expression of miR-181a-5p can be significantly corrected, but still failed to reach the level of healthy people. While the expression of Notch1 is significantly increased in ITP patients, and could not reach the level of healthy people after effective treatment.

Research progress of inflammatory cytokines in rheumatoid arthritis / 中国药理学通报

Rheumatoid arthritis (RA) is the most common eause of autoimmune arthritis in the world.In RA patients serum or plasma cytokine levels may indicate the severity of the disease.Cytokine gene polymorphism can be used as a marker of RA susceptibility and severity.Rheumatoid arthritis is a systemic connective tissue disease.Not only joints, but other organs (lungs.lymph nodes, spleen, skin, heart or eyes) may also he involved.'Hie main goal of treatment for rheumatoid arthritis is to avoid joint destruction through early and aggressive anti-inflammatory treatment.In the past few decades, various therapies were used for patients when methotrexate was ineffective or intolerant to alter the joint and systemic prognosis and the patients' disability.Among them, cytokine targeted therapy have long been identified to be the most promising therapy.This article re- views the effector functions of different inflammatory factors and their role in the RA pathogenesis and the targeted inhibitors targeting inflammatory factors that can currently be used for the treatment of RA.

Confirming the TMEM232 gene associated with atopic dermatitis through targeted capture sequencing.

Atopic dermatitis (AD) is a common and complex skin disorder, and the 5q22.1 region had been reported to be associated with AD. To confirm the susceptibility gene for AD in the 5q22.1 region by haplotype and targeted capture sequencing. The haplotypes were reconstructed with the genotyping data of four SNPs and six deletions from 3624 Chinese Hans AD patients and 5076 controls. The targeted capture sequencing spanning 5q22.1 region was performed in the selected samples. The gene level enrichment analysis was done using loss of function variants. A total of 62 haplotypes were found, and the H15 haplotype had the strongest association with AD (P = 3.92 × 10-10, OR 0.17, 95% CI 0.09-0.32). However, no co-segregation mutation sites were found in the sequencing analysis within the 16 selected samples, while the enrichment analysis indicated that TMEM232 was significantly associated with AD (P = 7.33 × 10-5, OR 0.33, 95% CI 0.19-0.58). This study confirms previous findings that the TMEM232 gene is associated with AD by haplotype analysis and targeted capture sequencing.

A Common Variant at 11q23.3 Is Associated with Susceptibility to Atopic Dermatitis in the Han Chinese Population.

Background: Genome-wide association studies (GWASs) have identified many genetic variants that are risk factors for numerous immune-mediated diseases. In particular, different immune-mediated diseases have been found to share the same susceptibility loci. Therefore, exploring the genetic overlap between atopic dermatitis (AD) and other immune-mediated diseases in more detail may help identify additional shared susceptibility loci among common immune-mediated diseases. Recent evidence suggests that the 11q23.3 locus is a susceptibility locus shared among multiple immune-mediated diseases. Objective: This study was designed to investigated whether SNPs at the chromosome 11q23.3 locus are associated with AD in the Han Chinese population. Methods: In total, 16 SNPs within the 11q23.3 locus were genotyped using TaqMan assays for 1,012 AD cases and 1,362 controls. From these SNPs, we selected rs638893 with an association values of p < 5 × 10-2 for AD for further analysis in an independent replication study using the Sequenom MassARRAY system to genotype an additional (consisting of 1,288 cases and 1,380 controls). The combined analyses were performed in two stages using a meta-analytical method. Results: We identified a common variant at 11q23.3 (rs638893), that was significantly associated (p = 1.58 × 10-3, OR = 1.22) with AD. The genotype-based association analysis revealed that the recessive model provided the best fit for rs638893. Conclusion: Our study identified a variant on chromosome 11q23.3 that likely confers susceptibility to AD, thereby advancing our understanding of the genetic basis of this disease.

Molecular Diagnosis of Neurofibromatosis by Multigene Panel Testing.

Neurofibromatosis (NF) is an autosomal genetic disorder for which early and definite clinical diagnoses are difficult. To identify the diagnosis, five affected probands with suspected NF from unrelated families were included in this study. Molecular analysis was performed using multigene panel testing and Sanger sequencing. Ultradeep sequencing was used to analyze the mutation rate in the tissues from the proband with mosaic mutations. Three different pathogenic variants of the NF1 gene were found in three probands who mainly complained of café-au-lait macules (CALMs), including one frameshift variant c.5072_5073insTATAACTGTAACTCCTGGGTCAGGGAGTACACCAA:p.Tyr1692Ilefs in exon 37, one missense variant c.3826C > T:p.Arg1276Ter in exon 28, and one splicing variant c.4110 + 1G > T at the first base downstream of the 3'-end of exon 30. One NF1 gene mosaic variant was found in a proband who complained of cutaneous neurofibroma with the frameshift variant c.495_498del:p.Thr165fs in exon 5, and ultradeep sequencing showed the highest mutation rate of 10.81% in cutaneous neurofibromas. A frameshift variant, c.36_39del:p.Ser12fs in exon 1 of the NF2 gene, was found in a proband who presented with skin plaques and intracranial neurogenic tumors. All of these pathogenic variants were heterozygous, one was not reported, and one not in Chinese before. This study expands the pathogenic variant spectrum of NF and demonstrates the clinical diagnosis.

Mechanism of tanshinone IIA to prevent spontaneous breast cancer in mice / 药学学报

To explore the effect of tanshinone IIA (TanIIA) on the occurrence and development of breast cancer, we employed the mouse mammary tumor virus-polyomavirus middle T antigen (MMTV-PyMT) transgenic mice as a spontaneous breast cancer mouse model. Animal welfare and experimental procedures were in accordance with the regulations of the Animal Ethics Committee of Nanjing University of Chinese Medicine. The animals were divided into control group, low-dose TanIIA treatment group (30 mg·kg-1·day-1), and high-dose TanIIA treatment group (60 mg·kg-1·day-1). The treatment was administered orally and daily for 5 weeks. The mice were sacrificed after final treatment. Mammary gland and lung were collected for histopathology studies. We evaluated the chemoprophylaxis effect of TanIIA on breast cancer in mice according to the pathological characteristics of breast cancer at different stages of development. Immunofluorescence staining were employed for blood vessel analysis. The expression levels of E-cadherin, proliferating nuclear antigen (PCNA), and oncogene c-Myc were detected by immunohistochemistry. Flow cytometry was used to analyze cell cycle and Cytoscape was used to construct drug-disease protein-protein interaction (PPI) network. Our results showed that TanIIA inhibits breast tumor progression by delaying malignancy from adenoma to early carcinoma, and inhibits blood vessel formation during tumor development. TanIIA (60 mg·kg-1·day-1) inhibits the expression levels of PCNA and c-Myc, upregulates the expression of E-cadherin. In addition, cell cycle experiments showed that the cell cycle of PyMT primary mammary cells in the high-dose TanIIA group was arrested in the G0/G1 phase. Our study demonstrated that TanIIA can significantly inhibit breast tumor progression in MMTV-PyMT mouse model, which may be related to the inhibition of angiogenic switch and cell cycle arrest.

Effect of astragaloside IV on the expression of NOD-like receptor protein 3 inflammasome in neonatal rats with hypoxic-ischemic brain damage / 中国当代儿科杂志

OBJECTIVE@#To study the effect of astragaloside IV (AS-IV) on NOD-like receptor protein 3 (NLRP3) inflammasome in neonatal rats with hypoxic-ischemic brain damage (HIBD).@*METHODS@#A total of 24 Sprague-Dawley rats, aged 7 days, were randomly divided into a sham-operation group, an HIBD group, and an AS-IV treatment group, with 8 rats in each group. After 24 hours of modeling, brain tissue was collected for hematoxylin-eosin staining, yo-PRO-1 staining, and EthD-2 immunofluorescent staining in order to observe the cerebral protection effect of AS-IV in vivo. HT22 cells were used to prepare a model of oxygen-glycogen deprivation (OGD), and a concentration gradient (50-400 μmol/L) was established for AS-IV. CCK-8 assay was used to measure the viability of HT22 cells. RT-PCR and Western blot were used to observe the effect of different concentrations of AS-IV on the mRNA and protein expression of NLRP3, gasdermin D (GSDMD), caspase-1, and interleukin-1β (IL-1β).@*RESULTS@#Yo-Pro-1 and EthD-2 staining showed that compared with the sham-operation group, the HIBD group had an increase in pyroptotic cells with a small number of necrotic cells, and the AS-IV group had reductions in both pyroptotic and necrotic cells. Compared with the sham-operation group, the HIBD group had significantly higher protein expression levels of NLRP3, IL-1β, caspase-1, and GSDMD (@*CONCLUSIONS@#AS-IV may alleviate HIBD in neonatal rats by inhibiting the expression of NLRP3, GSDMD, caspase-1, and IL-1β.

Validation of Susceptibility Loci for Vitiligo Identified by GWAS in the Chinese Han Population.

Forty-nine susceptible loci have been reported to be significantly associated with vitiligo by genome-wide association studies (GWASs) in European-derived whites. To date, some of these reported susceptibility loci have not yet been validated in the Chinese Han population. The purpose of this study was to examine whether the 16 reported susceptible loci in European-derived whites were associated with vitiligo in the Chinese Han population. Imputation was performed using our previous GWAS dataset by IMPUTE v2.2.2. The 16 imputed top single-nucleotide polymorphisms (SNPs) with suggestive signals, together with the reported SNPs, were genotyped in a total of 2581 patients and 2579 controls by the Sequenom MassARRAY system. PLINK 2.0 software was used to perform association analysis. The dbSNP database, HaploReg, and eQTL data were adopted to annotate the biological function of the SNPs. Finally, four SNPs from three loci were significantly associated with vitiligo, including rs3747517 (P = 1.29 × 10-3, OR = 0.87) in 2q24.2, rs4807000 (P = 7.78 × 10-24, OR = 0.66) and rs6510827 (P = 3.65 × 10-5, OR = 1.19) in 19p13.3, and rs4822024 (P = 6.37 × 10-10, OR = 0.67) in 22q13.2. According to the dbSNP database, rs3747517 is a missense variant of IFIH1, rs4807000 and rs6510827 are located in TICAM1, and rs4822024 is located 6 kb upstream of TEF. Further bioinformatics analysis by HaploReg and eQTL found that rs4807000, rs6510827, and rs4822024 are involved in regulating gene expression. Our study revealed the strong association of 2q24.2 (rs3747517), 19p13.3 (rs4807000, rs6510827), and 22q13.2 (rs4822024) with the risk of vitiligo in the Chinese Han population, which implicates common factors for vitiligo across different ethnicities, and helps expand the understanding of the genetic basis of this disease.

Double Lock of a Potent Human Monoclonal Antibody against SARS-CoV-2

Receptor recognition and subsequent membrane fusion are essential for the establishment of successful infection by SARS-CoV-2. Halting these steps can cure COVID-19. Here we have identified and characterized a potent human monoclonal antibody, HB27, that blocks SARS-CoV-2 attachment to its cellular receptor at sub-nM concentrations. Remarkably, HB27 can also prevent SARS-CoV-2 membrane fusion. Consequently, a single dose of HB27 conferred effective protection against SARS-CoV-2 in two established mouse models. Rhesus macaques showed no obvious adverse events when administrated with 10-fold of effective dose of HB27. Cryo-EM studies on complex of SARS-CoV-2 trimeric S with HB27 Fab reveal that three Fab fragments work synergistically to occlude SARS-CoV-2 from binding to ACE2 receptor. Binding of the antibody also restrains any further conformational changes of the RBD, possibly interfering with progression from the prefusion to the postfusion stage. These results suggest that HB27 is a promising candidate for immuno-therapies against COVID-19. HighlightsO_LISARS-CoV-2 specific antibody, HB27, blocks viral receptor binding and membrane fusion C_LIO_LIHB27 confers prophylactic and therapeutic protection against SARS-CoV-2 in mice models C_LIO_LIRhesus macaques showed no adverse side effects when administered with HB27 C_LIO_LICryo-EM studies suggest that HB27 sterically occludes SARS-CoV-2 from its receptor C_LI

SARS-CoV-2 infection causes transient olfactory dysfunction in mice

Olfactory dysfunction caused by SARS-CoV-2 infection represents as one of the most predictive and common symptoms in COVID-19 patients. However, the causal link between SARS-CoV-2 infection and olfactory disorders remains lacking. Herein we demonstrate intranasal inoculation of SARS-CoV-2 induces robust viral replication in the olfactory epithelium (OE), resulting in transient olfactory dysfunction in humanized ACE2 mice. The sustentacular cells and Bowmans gland cells in OE were identified as the major targets of SARS-CoV-2 before the invasion into olfactory sensory neurons. Remarkably, SARS-CoV-2 infection triggers cell death and immune cell infiltration, and impairs the uniformity of OE structure. Combined transcriptomic and proteomic analyses reveal the induction of antiviral and inflammatory responses, as well as the downregulation of olfactory receptors in OE from the infected animals. Overall, our mouse model recapitulates the olfactory dysfunction in COVID-19 patients, and provides critical clues to understand the physiological basis for extrapulmonary manifestations of COVID-19.

Five novel and highly efficient endophytic fungi isolated from Huperzia serrata expressing huperzine A for the treatment of Alzheimer's disease.

Huperzine A (Hup A) is an important drug for treating Alzheimer's disease (AD) and mainly extracted from the Huperzia serrata (Thunb.) Trevis. (Lycopodiaceae) (HS). Nevertheless, the content of Hup A in HS is very low of 0.007% with growing circle of 8 to 10 years, and the chemical synthesis of Hup A still has some insurmountable limitations in the industrialized production. So, the available resources of Hup A for clinical treatment of AD are scarce. The purpose of this work was to construct a biosynthesis platform based on the endophytic fungi from HS. In this work, five endophytic fungi Mucor racemosus NSH-D, Mucor fragilis NSY-1, Fusarium verticillioides NSH-5, Fusarium oxysporum NSG-1, and Trichoderma harzianum NSW-V were firstly found and isolated from the Chinese folk medicine HS, which were identified according to their morphological characteristics and nuclear ribosomal DNA ITS sequences. The highest efficient fungus could effectively biosynthesize Hup A in a liquid culture of 319.8 ± 0.17 mg/L which were 112 times higher than that of other reported conventional endophytic fungi. Moreover, these fungi with higher hereditary stability could possess the initial expressing ability of Hup A after 40 generations, and the expressed Hup A from these biosynthesis systems has prior physicochemical properties, a better inhibition activity of acetylcholinesterase and a lower cytotoxicity compared with the listed active pharmaceutical ingredients (APIs) of Hup A. These results provide promising alternative resources for producing Hup A at an industrial scale by biosynthesis, and it may also shed light on millions of AD patients. KEY POINTS: • Five novel endophytic fungi with high stability could highly express prior Hup A Graphical abstract.

Structural basis for neutralization of SARS-CoV-2 and SARS-CoV by a potent therapeutic antibody

The COVID-19 pandemic caused by the SARS-CoV-2 virus has resulted in an unprecedented public health crisis. There are no approved vaccines or therapeutics for treating COVID-19. Here we reported a humanized monoclonal antibody, H014, efficiently neutralizes SARS-CoV-2 and SARS-CoV pseudoviruses as well as authentic SARS-CoV-2 at nM level by engaging the S receptor binding domain (RBD). Importantly, H014 administration reduced SARS-CoV-2 titers in the infected lungs and prevented pulmonary pathology in hACE2 mouse model. Cryo-EM characterization of the SARS-CoV-2 S trimer in complex with the H014 Fab fragment unveiled a novel conformational epitope, which is only accessible when the RBD is in open conformation. Biochemical, cellular, virological and structural studies demonstrated that H014 prevents attachment of SARS-CoV-2 to its host cell receptors. Epitope analysis of available neutralizing antibodies against SARS-CoV and SARS-CoV-2 uncover broad cross-protective epitopes. Our results highlight a key role for antibody-based therapeutic interventions in the treatment of COVID-19. One sentence summaryA potent neutralizing antibody conferred protection against SARS-CoV-2 in an hACE2 humanized mouse model by sterically blocking the interaction of the virus with its receptor.

Rapid adaptation of SARS-CoV-2 in BALB/c mice: Novel mouse model for vaccine efficacy

Coronavirus disease 2019 (COVID-19) threatens global public health and economy. In order to develop safe and effective vaccines, suitable animal models must be established. Here we report the rapid adaption of SARS-CoV-2 in BALB/c mice, based on which a convenient, economical and effective animal model was developed. Specifically, we found that mouse-adapted SARS-CoV-2 at passage 6 (MACSp6) efficiently infected both aged and young wild-type BALB/c mice, resulting in moderate pneumonia as well as inflammatory responses. The elevated infectivity of MACSp6 in mice could be attributed to the substitution of a key residue (N501Y) in the receptorbinding domain (RBD). Using this novel animal model, we further evaluated the in vivo protective efficacy of an RBD-based SARS-CoV-2 subunit vaccine, which elicited highly potent neutralizing antibodies and conferred full protection against SARS-CoV-2 MACSp6 challenge. This novel mouse model is convenient and effective in evaluating the in vivo protective efficacy of SARS-CoV-2 vaccine. SummaryThis study describes a unique mouse model for SARS-CoV-2 infection and confirms protective efficacy of a SARS-CoV-2 RBD subunit vaccine.

An artificial intelligence system reveals liquiritin inhibits SARS-CoV-2 by mimicking type I interferon

The pandemic COVID-19 has spread to all over the world and greatly threatens safety and health of people. COVID-19 is highly infectious and with high mortality rate. As no effective antiviral treatment is currently available, new drugs are urgently needed. We employed transcriptional analysis to uncover potential antiviral drugs from natural products or FDA approved drugs. We found liquiritin significantly inhibit replication of SARS-CoV-2 in Vero E6 cells with EC50 = 2.39 M. Mechanistically, we found liquiritin exerts anti-viral function by mimicking type I interferon. Upregulated genes induced by liquiritin are enriched in GO categories including type I interferon signaling pathway, negative regulation of viral genome replication and etc. In toxicity experiment, no death was observed when treated at dose of 300 mg/kg for a week in ICR mice. All the organ indexes but liver and serum biochemical indexes were normal after treatment. Liquiritin is abundant in licorice tablet (~0.2% by mass), a traditional Chinese medicine. Together, we recommend liquiritin as a competitive candidate for treating COVID-19. We also expect liquiritin to have a broad and potent antiviral function to other viral pathogens, like HBV, HIV and etc.

Antibody responses to SARS-CoV-2 in COVID-19 patients: the perspective application of serological tests in clinical practice

BackgroundWe aim to investigate the profile of acute antibody response in COVID-19 patients, and provide proposals for the usage of antibody test in clinical practice. MethodsA multi-center cross-section study (285 patients) and a single-center follow-up study (63 patients) were performed to investigate the feature of acute antibody response to SARS-CoV-2. A cohort of 52 COVID-19 suspects and 64 close contacts were enrolled to evaluate the potentiality of the antibody test. ResultsThe positive rate for IgG reached 100% around 20 days after symptoms onset. The median day of seroconversion for both lgG and IgM was 13 days after symptoms onset. Seroconversion of IgM occurred at the same time, or earlier, or later than that of IgG. IgG levels in 100% patients (19/19) entered a platform within 6 days after seroconversion. The criteria of IgG seroconversion and > 4-fold increase in the IgG titers in sequential samples together diagnosed 82.9% (34/41) of the patients. Antibody test aided to confirm 4 patients with COVID-19 from 52 suspects who failed to be confirmed by RT-PCR and 7 patients from 148 close contacts with negative RT-PCR. ConclusionIgM and IgG should be detected simultaneously at the early phase of infection. The serological diagnosis criterion of seroconversion or the >; 4-fold increase in the IgG titer is suitable for a majority of COVID-19 patients. Serologic test is helpful for the diagnosis of SARS-CoV-2 infection in suspects and close contacts.