A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-contain...A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-containing foods or cross-reactivity between α-gliadin and non-gluten foods consumed on a GFD. We measured the reactivity of affinity-purified polyclonal and monoclonal α-gliadin 33-mer peptide antibodies against gliadin and additional food antigens commonly consumed by patients on a GFD using ELISA and dot-blot. We also examined the immune reactivity of these antibodies with various tissue antigens. We observed significant immune reactivity when these antibodies were applied to cow’s milk, milk chocolate, milk butyrophilin, whey protein, casein, yeast, oats, corn, millet, instant coffee and rice. To investigate whether there was cross-reactivity between α-gliadin antibody and different tissue antigens, we measured the degree to which this antibody bound to these antigens. The most significant binding occurred with asialoganglioside, hepatocyte, glutamic acid decarboxylase 65, adrenal 21-hydroxylase, and various neural antigens. The specificity of anti-α-gliadin binding to different food and tissue antigens was demonstrated by absorption and inhibition studies. We also observed significant cross-reactivity between α-gliadin 33-mer and various food antigens, but some of these reactions were associated with the contamination of non-gluten foods with traces of gluten. The consumption of cross-reactive foods as well as gluten-contaminated foods may be responsible for the continuing symptoms presented by a subgroup of patients with coeliac disease. The lack of response of some CD patients may also be due to antibody cross-reactivity with non-gliadin foods. These should then be treated as gluten-like peptides and should also be excluded from the diet when the GFD seems to fail.展开更多
This review aimed to assess the occurrence of false-positive serological reaction between dengue and coronavirus disease 2019(COVID-19)and its implications for diagnosis.Evidence syntheses were conducted by systematic...This review aimed to assess the occurrence of false-positive serological reaction between dengue and coronavirus disease 2019(COVID-19)and its implications for diagnosis.Evidence syntheses were conducted by systematically reviewing available literature using multiple databases,including Web of Science,PubMed,Google Scholar and medRxiv.Among a total of 16 presented cases from clinical settings,cross-reaction to COVID-19 serological tests was observed in two(12.5%)dengue-positive patients,while 14 patients(87.5%)confirmed positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)showed a cross-reaction with dengue serological tests,leading to misdiagnosis and mismanagement by attending clinicians.Of 1789 SARS-CoV-2-positive sera,cross-reaction to dengue serological tests was observed in 180 sera(10%),which is higher than the cross-reaction observed for SARS-CoV-2 in archived pre-COVID-19 sera positive for a dengue infection(75 of 811,9.2%,P=0.674).Clinicians in tropical regions are therefore advised to interpret serological tests with caution and use a more pragmatic approach to triage these infections.展开更多
To investigate the significance of the SARS-associated coronavirus (SARS-CoV) antibody,detected by ELISA and indirect immunofluorescence assays (IFA) for the SARS-CoV Vero E6 cell lysates,in non-SARS subjects, 114 ser...To investigate the significance of the SARS-associated coronavirus (SARS-CoV) antibody,detected by ELISA and indirect immunofluorescence assays (IFA) for the SARS-CoV Vero E6 cell lysates,in non-SARS subjects, 114 serum samples from healthy controls and 104 serum specimens from autoimmune disease patients were collected.The results of ELISA showed that among 114 sera from healthy controls,4 (3.5%) were positive of SARS-CoV-IgG antibody and 114 (100%) were all negative of SARS-CoV-IgM antibody;the specificity of SARS-CoV-IgG antibody for SARS patients was 96.5%,but the specificity of both SARS-CoV-IgG and -IgM antibodies for SARS patients was 100%.In 58 cases with SLE,positive rates of SARS-CoV-IgG and -IgM antibodies were 32.8% (19/58) and 8.6% (5/58),respectively,in which 11 cases (19%) were positive of both SARS-CoV-IgG and -IgM antibodies;in 10 cases with SS,positive rate of both SARS-CoV-IgG and -IgM antibodies was 10% (1/10);in 16 cases with MCTD,positive rate of SARS-CoV-IgG was 37.5% (6/16),positive rate of both SARS-CoV-IgG and -IgM antibodies was 6.3% (1/16);in 20 cases with RA,one case was positive (5%) of SARS-CoV-IgG.However,of all samples with positive SARS-CoV-IgG and -IgM antibodies for autoimmune diseases and healthy controls,SARS-CoV RNA and antibodies were all negative by RT-PCR and IFA.All sera for negative or positive ELISA results were also negative or positive results using ELISA with Vero E6 cells lysates.These studies showed that SARS-CoV Vero E6 cell lysates for the ELISA to detect SARS-CoV antibodies could lead to the false-positive reactions or cross-reactions of SARS-CoV antibodies in non-SARS diseases and healthy controls,and the false-positive reactions or cross-reactions were related to Vero E6 cell lysates and autoantibodies in non-SARS population.Cellular & Molecular Immunology.2004;1(4): 304-307.展开更多
BACKGROUND The diagnosis of West Nile virus(WNV)is challenging due to short-term and low-level viremia,flavivirus cross-reactivity,and long immunoglobulin M(IgM)persistence.AIM To evaluate different methods for WNV de...BACKGROUND The diagnosis of West Nile virus(WNV)is challenging due to short-term and low-level viremia,flavivirus cross-reactivity,and long immunoglobulin M(IgM)persistence.AIM To evaluate different methods for WNV detection[reverse transcription-polymerase chain reaction(RT-PCR),IgM/IgG antibodies,IgG avidity]in serum,cerebrospinal fluid(CSF),and urine samples of patients with confirmed WNV infection.METHODS The study included patients with confirmed WNV neuroinvasive infection(n=62),asymptomatic WNV seropositive individuals(n=22),and individuals with false-positive WNV IgM antibodies(n=30).WNV RNA was detected using RT-PCR.A commercial ELISA was used to detect WNV IgM/IgG antibodies with confirmation of cross-reactive samples using a virus neutralization test(VNT).IgG-positive samples were tested for IgG avidity.RESULTS The WNV-RNA detection rates were significantly higher in the urine(54.5%)/serum(46.4%)than in CSF(32.2%).According to the sampling time,the WNV-RNA detection rates in urine collected within 7 days/8-14/≥15 days were 29.4/66.6/62.5%(P=0.042).However,these differences were not observed in the CSF.The median RT-PCR cycle threshold values were significantly lower in urine(32.5,IQR=28-34)than in CSF(34.5,IQR=33-36).The frequency of positive WNV IgM and IgG significantly differed according to the sampling time in serum but not in CSF.Positive IgM/IgG antibodies were detected in 84.3/9.3%of serum samples collected within 7 days,100/71.1%of samples collected 8-14,and 100%samples collected after≥15 days.Recent WNV infection was confirmed by low/borderline avidity index(AI)in 13.6%of asymptomatic individuals.A correlation between ELISA and AI was strong negative for IgM and strong positive for IgG.No significant correlation between ELISA IgG and VNT was found.CONCLUSION The frequency of WNV RNA and antibody detection depends on the sampling time and type of clinical samples.IgG avidity could differentiate recent WNV infections from long-persisting IgM antibodies.展开更多
文摘A subgroup of coeliac disease patients continues to experience symptoms even on a gluten-free diet (GFD). We attempted to determine whether these symptoms could be due to either cross-contamination with gluten-containing foods or cross-reactivity between α-gliadin and non-gluten foods consumed on a GFD. We measured the reactivity of affinity-purified polyclonal and monoclonal α-gliadin 33-mer peptide antibodies against gliadin and additional food antigens commonly consumed by patients on a GFD using ELISA and dot-blot. We also examined the immune reactivity of these antibodies with various tissue antigens. We observed significant immune reactivity when these antibodies were applied to cow’s milk, milk chocolate, milk butyrophilin, whey protein, casein, yeast, oats, corn, millet, instant coffee and rice. To investigate whether there was cross-reactivity between α-gliadin antibody and different tissue antigens, we measured the degree to which this antibody bound to these antigens. The most significant binding occurred with asialoganglioside, hepatocyte, glutamic acid decarboxylase 65, adrenal 21-hydroxylase, and various neural antigens. The specificity of anti-α-gliadin binding to different food and tissue antigens was demonstrated by absorption and inhibition studies. We also observed significant cross-reactivity between α-gliadin 33-mer and various food antigens, but some of these reactions were associated with the contamination of non-gluten foods with traces of gluten. The consumption of cross-reactive foods as well as gluten-contaminated foods may be responsible for the continuing symptoms presented by a subgroup of patients with coeliac disease. The lack of response of some CD patients may also be due to antibody cross-reactivity with non-gliadin foods. These should then be treated as gluten-like peptides and should also be excluded from the diet when the GFD seems to fail.
文摘This review aimed to assess the occurrence of false-positive serological reaction between dengue and coronavirus disease 2019(COVID-19)and its implications for diagnosis.Evidence syntheses were conducted by systematically reviewing available literature using multiple databases,including Web of Science,PubMed,Google Scholar and medRxiv.Among a total of 16 presented cases from clinical settings,cross-reaction to COVID-19 serological tests was observed in two(12.5%)dengue-positive patients,while 14 patients(87.5%)confirmed positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)showed a cross-reaction with dengue serological tests,leading to misdiagnosis and mismanagement by attending clinicians.Of 1789 SARS-CoV-2-positive sera,cross-reaction to dengue serological tests was observed in 180 sera(10%),which is higher than the cross-reaction observed for SARS-CoV-2 in archived pre-COVID-19 sera positive for a dengue infection(75 of 811,9.2%,P=0.674).Clinicians in tropical regions are therefore advised to interpret serological tests with caution and use a more pragmatic approach to triage these infections.
文摘To investigate the significance of the SARS-associated coronavirus (SARS-CoV) antibody,detected by ELISA and indirect immunofluorescence assays (IFA) for the SARS-CoV Vero E6 cell lysates,in non-SARS subjects, 114 serum samples from healthy controls and 104 serum specimens from autoimmune disease patients were collected.The results of ELISA showed that among 114 sera from healthy controls,4 (3.5%) were positive of SARS-CoV-IgG antibody and 114 (100%) were all negative of SARS-CoV-IgM antibody;the specificity of SARS-CoV-IgG antibody for SARS patients was 96.5%,but the specificity of both SARS-CoV-IgG and -IgM antibodies for SARS patients was 100%.In 58 cases with SLE,positive rates of SARS-CoV-IgG and -IgM antibodies were 32.8% (19/58) and 8.6% (5/58),respectively,in which 11 cases (19%) were positive of both SARS-CoV-IgG and -IgM antibodies;in 10 cases with SS,positive rate of both SARS-CoV-IgG and -IgM antibodies was 10% (1/10);in 16 cases with MCTD,positive rate of SARS-CoV-IgG was 37.5% (6/16),positive rate of both SARS-CoV-IgG and -IgM antibodies was 6.3% (1/16);in 20 cases with RA,one case was positive (5%) of SARS-CoV-IgG.However,of all samples with positive SARS-CoV-IgG and -IgM antibodies for autoimmune diseases and healthy controls,SARS-CoV RNA and antibodies were all negative by RT-PCR and IFA.All sera for negative or positive ELISA results were also negative or positive results using ELISA with Vero E6 cells lysates.These studies showed that SARS-CoV Vero E6 cell lysates for the ELISA to detect SARS-CoV antibodies could lead to the false-positive reactions or cross-reactions of SARS-CoV antibodies in non-SARS diseases and healthy controls,and the false-positive reactions or cross-reactions were related to Vero E6 cell lysates and autoantibodies in non-SARS population.Cellular & Molecular Immunology.2004;1(4): 304-307.
基金Supported by the Croatian Science Foundation,No.IP-2016-06-7456:CRONEUROARBOthe European Union Next Generation EU project supported by the Ministry of Science and Education of the Republic of Croatia,No.NPOO 1 of Croatian Veterinary Institute:FLAVIR.
文摘BACKGROUND The diagnosis of West Nile virus(WNV)is challenging due to short-term and low-level viremia,flavivirus cross-reactivity,and long immunoglobulin M(IgM)persistence.AIM To evaluate different methods for WNV detection[reverse transcription-polymerase chain reaction(RT-PCR),IgM/IgG antibodies,IgG avidity]in serum,cerebrospinal fluid(CSF),and urine samples of patients with confirmed WNV infection.METHODS The study included patients with confirmed WNV neuroinvasive infection(n=62),asymptomatic WNV seropositive individuals(n=22),and individuals with false-positive WNV IgM antibodies(n=30).WNV RNA was detected using RT-PCR.A commercial ELISA was used to detect WNV IgM/IgG antibodies with confirmation of cross-reactive samples using a virus neutralization test(VNT).IgG-positive samples were tested for IgG avidity.RESULTS The WNV-RNA detection rates were significantly higher in the urine(54.5%)/serum(46.4%)than in CSF(32.2%).According to the sampling time,the WNV-RNA detection rates in urine collected within 7 days/8-14/≥15 days were 29.4/66.6/62.5%(P=0.042).However,these differences were not observed in the CSF.The median RT-PCR cycle threshold values were significantly lower in urine(32.5,IQR=28-34)than in CSF(34.5,IQR=33-36).The frequency of positive WNV IgM and IgG significantly differed according to the sampling time in serum but not in CSF.Positive IgM/IgG antibodies were detected in 84.3/9.3%of serum samples collected within 7 days,100/71.1%of samples collected 8-14,and 100%samples collected after≥15 days.Recent WNV infection was confirmed by low/borderline avidity index(AI)in 13.6%of asymptomatic individuals.A correlation between ELISA and AI was strong negative for IgM and strong positive for IgG.No significant correlation between ELISA IgG and VNT was found.CONCLUSION The frequency of WNV RNA and antibody detection depends on the sampling time and type of clinical samples.IgG avidity could differentiate recent WNV infections from long-persisting IgM antibodies.
