3种方法检测286例生殖道沙眼衣原体的分析

目的分析比较酶联免疫吸附试验(ELISA)、核酸扩增聚合酶链反应(PCR)荧光法和免疫层析法在检测泌尿生殖系统沙眼衣原体(CT)感染中的应用效果。方法分别采用ELISA、核酸扩增PCR荧光法和免疫层析法检测泌尿生殖系统的CT抗原,同时用细胞培养法作为"金标准"。结果共检286例标本,ELISA、核酸扩增PCR荧光法和免疫层析法的特异性和灵敏度分别为99.1%和95.5%;98.2%和97.0%;99.5%和73.6%。结论 ELISA法与核酸扩增PCR荧光法具有较一致灵敏度和特异性,均可为临床治疗和监测性病提供可靠的依据;免疫层析法虽然操作简便,但灵敏度较差。

梅毒抗体筛查结果分析及其检测方法联合应用评价

目的:分析梅毒抗体(TP-Ab)筛查阳性率及侵入性检查前检测的必要性,评价其检测方法联合应用的临床价值。方法:对6 584例患者血清样本采用梅毒酶联免疫吸附试验(TP-ELISA)初筛TP-Ab,阳性样本再以梅毒螺旋体明胶吸附试验(TPPA)、胶体金法及甲苯胺红不加热血清试验(TRUST)检测,观察不同性别、年龄段、侵入性检查前、输血及术前阳性率差异;比较4种梅素筛查方法阳性率差异,以及在ELISA初筛不同吸光度值(OD值)区间各方法阳性率的差异。结果:TP-Ab初筛阳性率为3.2%,40岁以上人群高于40岁以下人群,差异有统计学意义(P<0.05),但男女性别间、侵入性检查前、输血及术前比较差异无统计学意义(P>0.05);23例临床确诊梅毒病例TP-ELISA、TPPA及胶体金法阳性率均为100%,TRUST阳性率为65%;TP-ELISA与TPPA、胶体金法阳性率分别在0.14≤OD<2组和0.14≤OD<1组中比较;差异有统计学意义(P<0.05)。结论:TPELISA法适用于患者侵入性检查前、输血和术前TP-Ab筛查,多种检测方法联合应用可为临床筛查梅毒提供更准确全面的实验诊断依据。

Levels of v5 and v6 CD44 splice variants in serum of patients with colorectal cancer are not correlated with pT stage,histopathological grade of malignancy and clinical features

AIM:This study was designed to compare the levels of v5 and v6 splice variants of CD44 evaluated using EITSA test in the serum of patients with colorectal cancer in different stages of progression of the disease estimated in pT stage according to WHO score,histopathological grade of malignancy and some clinicopathological features. METHODS:The serum obtained from 114 persons with colorectal adenocarcinomas was examined using ELISA method,pT stage and grade of malignancy of the tumour were examined in formalin fixed and paraffin embedded materials obtained during operation. RESULTS:Only the level of CD44 v5 in the serum of patients before operation with G2 pT4 tumour was lower than that in other probes and the difference was statistically significant. We did not find any other correlations between the level of v5 and v6 CD44 variants and other evaluated parameters. CONCLUSION:The level of CD44 v5 and v6 estimated by ELISA test in the serum can not be used as a prognostic factor in colorectal cancer.

Recent Developments in SARS-CoV-2 Neutralizing Antibody Detection Methods

The ongoing Coronavirus disease 19 pandemic has likely changed the world in ways not seen in the past.Neutralizing antibody(NAb)assays play an important role in the management of the severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)outbreak.Using these tools,we can assess the presence and duration of antibody-mediated protection in naturally infected individuals,screen convalescent plasma preparations for donation,test the efficacy of immunotherapy,and analyze NAb titers and persistence after vaccination to predict vaccine-induced protective effects.This review briefly summarizes the various methods used for the detection of SARS-CoV-2 NAbs and compares their advantages and disadvantages to facilitate their development and clinical application.

Detection of anti-Helicobacter pyloriantibodies in serum and duodenal fluid in peptic gastroduodenal disease

AIM:To study the diagnosis of Helicobacter pylori(H pylori) infection through the determination of serum levels of anti- H pylori IgG and IgA antibodies,and the levels of anti-H pylori IgA antibodies in duodenal fluid. METHODS:Data were collected from 93 patients submitted to upper digestive endoscopy due to dyspeptic symptoms. The patients were either negative(group A)or positive (group B)to H pylori by means of both histological detection and urease tests.Before endoscopy,peripheral blood was collected for the investigation of anti-H pylori IgG and IgA antibodies.To perform the urease test,biopsies were obtained from the gastric antrum.For the histological evaluation,biopsies were collected from the gastric antrum (greater and lesser curvatures)and the gastric body. Following this,duodenal fluid was collected from the first and second portions of the duodenum.For the serological assaying of anti-Hpylori IgG and IgA,and anti-Hpylori IgA in duodenal fluids,the ELISA method was utilized. RESULTS:The concentration of serum IgG showed sensitivity of 64.0%,specificity of 83.7%,positive predictive value of 82.0%,negative predictive value of 66.6% and accuracy of 73.1% for the diagnosis of H pylori infection.For the same purpose,serum IgA showed sensitivity of 72.0%, specificity of 65.9%,positive predictive value of 72.0%, negative predictive value of 67.4% and accuracy of 69.8%. If the serological tests were considered together,i.e.when both were positive or negative,the accuracy was 80.0%, sensitivity was 86.6%,specificity was 74.2%,positive predictive value was 74.2% and negative predictive value was 86.6%.When values obtained in the test for detecting IgA in the duodenal fluid were analyzed,no significant difference(P=0.43)was observed between the values obtained from patients with or without H pylori infection. CONCLUSION:The results of serum IgG and IgA tests for H pylori detection when used simultaneously,are more efficient in accuracy,sensitivity and negative predictive value, than those when used alone.The concentration of IgA antibodies in duodenal fluid is not useful in identifying patients with or without H pylori.

Do Occupational Factors Render Army Service a High-Leptospirosis-Risk Occupation?

Objective: Leptospirosis is a known zoonotic disease which is closely related to certain high-risk occupational group. This study aimed to identify the risk factors associated with seropositive leptospirosis among army personnel. Methodology: A cross sectional study was conducted involving 616 army personnel using a self-administered questionnaire. The questionnaire consisted of sociodemographic, occupational and environmental data as well as recreational activities history. Serum sample for leptospirosis was taken for screening with IgM Enzyme-linked Immunosorbent Assay (IgM ELISA) test. Positive tests were confirmed by Microscopic Agglutination Test (MAT). Results: All respondents were male, Malays and married with the mean age of 29.28 (7.15) years old. The mean duration of working was 11.50 (7.75). Majority of the respondents were non-officer and riflemen, smokers (455 (73.9%), stayed inside the camp and engaged in recreational activities. The mean duration of employment was 11.50 (7.75) years. The overall seroprevalence of leptospirosis was 16.2% (95% CI: 13.32, 19.15) and the predominant pathogenic serovar identified was Terengganu (38.2%). Those who had lower educational levels were more protective for positive leptospirosis compared to those who have only primary education (OR: 0.32;95% CI: 0.14, 0.76;p = 0.009). Conclusion: Despite being named as one of the high-risk occupations for leptospirosis, this study found no significant occupational factors related to leptospirosis seropositivity among army personnel.

The clinical significance evaluation of serum β_2-microglobulin for thyroid cancer patients

Objective： The aim of this study was to investigate the clinical value and relevance on the serum β2-microglobulin （β2-MG） of patients with thyroid cancer. Methods： One thousand and two normal cases, 95 thyroid cancer patients and 243 nodular goiter patients were selected to measure serum β2-MG levels using double-antibody sandwich enzyme-linked immunosorbent assay （ELISA）. Results： The positive rate of 7.78% in normal population （78/1002） and 31.57% in thyroid cancer patients （30/95）. There were significant differences between the normal population and thyroid cancer patients （X2 = 55.352; P = 0.000）. The positive rate of 7.81% in nodular goiter patients （19/243） and there were no significant differences between the normal population and nodular goiter patients （X2 = 0.0004; P = 0.986）, but significant differences between nodular goiter patients and thyroid cancer patients （x2 = 31.106; P = 0.000）. Meanwhile, the significant difference of the positive rate existed in between the various pathological types of thyroid cancer （X2 = 10.015; P = 0.007）, anaplastic thyroid cancer patients with the highest positive rate and The significant difference was found between the positive lymph node metastasis groups and negative lymph node metastasis groups （x2 = 4.441; P = 0.035）, the presence of distant metastasis group and absence of distant metastasis group （X2 = 9.795; P = 0.002）. Conclusion： Serum β2-MG levels and prognosis of thyroid cancer patients was negatively correlated. It showed important clinical value to detect the level of β2-MG in the early diagnosis, prognosis and the clinical observation for thyroid cancer patients.

Canine Herpesvirus Seroprevalence and Associated Factors in Dogs of Mexico

Canine herpesvirus (CHV-1) causes disease associated with high mortality in infect-ed puppies, which represents large financial losses for dog breeders. Since CHV-1 at the time of the study he had not been reported in Mexico, the main objective of this study was to determine the prevalence of antibodies against CHV-1 in canine kennels in the metropolitan area of Mexico City. A commercial enzyme-linked immuno-sorbent assay (ELISA) was used, and the results were compared to those of a viral neutralization test. The ELISA kit uses the complete viral particle as the antigen. The plaque reduction neutralization test was combined with the immunoperoxidase technique because of the low cytopathic effect of CHV-1. Neutralizing antibodies were also detected in 20 randomly selected samples. The prevalence of CHV-1 with ELISA was 87%. The concordance between ELISA and serum neutralization (SN) was 0.1129, the sensitivity of the ELISA against SN was 1.0 (100%), the positive predic-tive value was 0.39 (39%), and the negative predictive value was 1 (100%). These results show that ELISA is useful for monitoring the dog population for CHV-1;a positive test result requires confirmation with an SN test, and a negative ELISA result indicates a high probability of being SN-negative. The only variables that were sta-tistically associated with CHV-1 prevalence were breed and kennel. A statistically significant relationship between the degree of ELISA and SN titer was obtained, with a confidence level of 95%. None of the clinical presentation factors was statistically significant. These results suggest that most of the canine population studied in Mex-ico is in a herpesvirus latency state.

Accuracy of a new rapid diagnostic test for urinary antigen detection and assessment of drug treatment in opisthorchiasis

Background Screening for opisthorchiasis,a parasitic worm infection affecting many millions of people in Southeast Asia,has traditionally relied on faecal egg examination such as the formalin-ethyl acetate concentration technique(FECT)and Kato-Katz method.Although the urinary enzyme-linked immunosorbent assay(ELISA)has been used more recently,we developed a urinary antigen-based rapid diagnostic test(RDT)to simplify diagnosis and as a point-of-care testing(POCT)and field applications for surveillance and control of opisthorchiasis.Methods A urinaryOpisthorchis viverrini(OV)-RDT was developed using immunochromatographic methodology with a specific monoclonal antibody against OV.The diagnostic performance of the urinary OV-RDT was compared to that of quantitative faecal FECT and urinary antigen ELISA(n=493).Cross-reactivities of urinary OV-RDT with other helminthiases coexisted withO.viverrini were determined(n=96).A field trial in the application of urinary OV-RDT was compared with urinary antigen ELISA at baseline screening and assessment of drug treatment outcomes in opisthorchiasis(n=1629).The McNemar chi-square,Kruskal-Wallis and Cohen’s kappa coefficient(κ-value)tests were used for statistical analyses.Results Urinary OV-RDT had sensitivity of 94.2%and specificity of 93.2%,compared to faecal FECT.Urinary OV-RDT had high diagnostic agreement(Kappa=0.842-0.874,P<0.001)and quantitative correlation with urinary antigen ELISA(Kruskal-Wallis tests=316.2,P<0.0001)and faecal FECT(Kruskal-Wallis tests=362.3,P<0.0001).The positive rates by OV-RDT,ELISA and FECT were 48.9%,52.5%and 49.3%,respectively.Cross-reactions of urinary OV-RDT with other helminthiases were few(2%).Field trials of urinary OV-RDT yielded comparable prevalence ofO.viverrini between urinary OV-RDT(53.2%)and urinary antigen ELISA(54.0%).OV screening showed high diagnostic agreement(kappa>0.8,P<0.0001)between urinary OV-RDT and urinary antigen ELISA.The cure rates of opisthorchiasis at 1 month post-praziquantel treatment determined by urinary OV-RDT(86.6%)and urinary antigen ELISA(80.5%)were similar(P>0.05).Conclusions The urinary OV-RDT test has high potential as a new tool for screening and evaluating treatment outcomes in opisthorchiasis.The ease of sample collection and simplicity of urinary OV-RDT may facilitate mass screening,control and elimination of opisthorchiasis,thereby contributing to a reduction in the disease burden in Southeast Asia.

Serologic study on the outbreak of acute upper respiratory tract infections caused by adenovirus 3

From April to June,2004,an outbreak of acute upper respiratory tract infections(AURTI)occurred in the north area of Jiangsu Province,China.Twenty throat swabs were collected with 13 of them presenting an adenovirus(Ad)-like cytopathogenic effect on HEp-2.These were verified as Ad by the electron microscope,direct immunofluorescence assay and Ad primer-mediated PCR.Moreover,they were identified as adenovirus type 3(Ad3)by type-specific PCR and sequencing of the amplification products.Subsequent serologic studies were carried out to finally diagnose and document the outbreak.The neutralization test of paired serum of six in nine cases show obviously increased antibodies titers.The positive rate of IgM,IgG and recovery phase neutralization antibodies of the cases were 3.7%,44.4%and 59.5%respectively while those of the controls were 0%,8.3%and 33.3%respectively.The P values of Chi-Square were 0.510,0.018 and 0.226 respectively.The concordance between IgG detected by ELISA and neutralization anti bodies detected by the neutralization test was 61.4%and the P value of Kappa was 0.070.By the serologic study,we can definitively diagnose that this outbreak of acute respiratory infections was caused by Adenovirus 3.