To explore the clinical diagnostic efficacy of antineutrophil cytoplasmic antibody associated vasculitis (AAV) by comparing the consistency and coincidence rate of serum anti-myeloperoxidase (MPO) antibody and anti-protease 3 (PR3) antibody detected by digital liquid chip method (DLCM) and enzyme-linked immunosorbent assay (ELISA). To provide reference for the selection of detection methods of anti-MPO antibody and anti-PR3 antibody in clinical laboratory. This study is a cross-sectional study, a total of 307 cases of antineutrophil cytoplasmic antibodies were detected in the Department of Clinical Immunology, West China Hospital of Sichuan University from January to March 2021. The serum samples and related clinical information were collected. At the same time, the levels of anti-MPO antibody and anti-PR3 antibody in serum samples were detected by ELISA and DLCM, indirect immunofluorescence (IIF) was used to re-test the differential samples between the two methods. SPSS 26.0 was used to analyze the test results, Cohen's kappa coefficient analysis was used to compare the consistency of the two methods, and paired chi-square test was used to compare the sensitivity and specificity of the two methods to AAV. The results showed that the positive cases of anti-MPO antibody detected by ELISA and DLCM were 63 and 44, and the negative cases were 244 and 263; the positive cases of anti-PR3 antibody detected by ELISA and DLCM were 34 and 28, and the negative cases were 273 and 279. The results of anti-MPO antibody and anti-PR3 antibody detected by the two methods had good consistency and coincidence rate, in which the total coincidence rate of anti-MPO antibody was 92.51%, the positive coincidence rate was 66.67%, and the negative coincidence rate was 99.18%. The results of consistency analysis showed that kappa=0.741 had well consistency. The total coincidence rate of anti-PR3 antibody is 96.74%, the positive coincidence rate is 76.47%, and the negative coincidence rate is 99.27%. The consistency analysis results show that kappa=0.821 had strong consistency. The results of IIF re-test of differential samples showed that the coincidence rate between DLCM and IIF was higher. The results of comparative analysis of anti-MPO antibody and anti-PR3 antibody showed that the specificity of DLCM was better than that of ELISA, and its sensitivity was lower than that of ELISA. In conclusion, the results of anti-MPO antibody and anti-PR3 antibody detected by DLCM were consistent with those of ELISA. In the combined detection of anti-MPO antibody and anti-PR3 antibody, the specificity of DLCM is better than that of ELISA.
Humans ; Antibodies, Antineutrophil Cytoplasmic/analysis* ; Myeloblastin ; Cross-Sectional Studies ; Sensitivity and Specificity ; Fluorescent Antibody Technique, Indirect ; Enzyme-Linked Immunosorbent Assay/methods*

OBJECTIVETo detect Bartonella henselae IgG antibody among healthy people in Changping, Beijing.

METHODSUsing indirect enzyme linked immunosorbent assay (ELISA) and immunofluorescence antibody assay (IFA) to detect IgG antibody of Bartonella henselae among human beings.

RESULTSThe sensitivity and specificity of ELISA were 70.6% and 91.6% respectively, with the positive predictive value of serological test as 82.2%, and the negative predictive value as 84.9%, based on results of IFA. The positive rate was 34.5% among 357 healthy people on indirect ELISA but was 35.6% among 239 people with IFA.

CONCLUSIONThe results indicated that the indirect ELISA was a very quick, sensitive and available method for detecting Bartonella henselae in human beings, as well as a high positive percent age of Bartonella henselae among the healthy people of Changping Beijing.

Adolescent ; Adult ; Antibodies, Bacterial ; immunology ; Bartonella henselae ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Female ; Fluorescent Antibody Technique, Indirect ; methods ; Humans ; Immunoglobulin G ; immunology ; Male ; Middle Aged ; Young Adult

OBJECTIVETo explore the temporal profile of serum antibody against coronavirus in patients with severe acute respiratory syndrome (SARS), and to evaluate the reliability of indirect immuno-fluorescence assay (IFA) in the diagnosis of SARS.

METHODSClinically confirmed SARS patients, suspected SARS patients, and controls were included in the study. IFA was used to detect the serum antibody against SARS coronavirus. General information about the subjects was collected using a standard questionnaire.

RESULTSThe positive rates of specific IgG and IgM against SARS virus within 10 days after onset of the disease were 55.1% and 16.3% respectively and then increased up to 89.8% for IgG and 65.3% for IgM. After 25 days of the onset of the disease, 90.9% patients became positive for both IgG and IgM. Results from chi-square for trend test revealed that the positive rates of both IgG and IgM increased with time (chi(2) for trend = 16.376, P = 0.00005 for IgG; chi(2) for trend = 28.736, P = 0.00000 for IgM). Sensitivity, specificity and agreement value of IFA regarding the diagnosis of SARS were all higher than 90%.

CONCLUSIONIFA can be used to assist diagnosis of SARS after 10 days of the onset of disease.

Antibodies, Viral ; blood ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect ; methods ; Humans ; Immunoglobulin G ; blood ; Immunoglobulin M ; blood ; SARS Virus ; immunology ; Severe Acute Respiratory Syndrome ; diagnosis

The integrity and transparency of cornea plays a key role in vision. Limbal Stem Cells (LSCs) are precursors of cornea, which are responsible for self-renewal and replenishing corneal epithelium. Though it is successful to cell replacement therapy for impairing ocular surface by Limbal Stem Cell Transplantation (LSCT), the mechanism of renew is unclear after LSCT. To real time follow-up the migration and differentiation of corneal transplanted epithelial cells after transplanting, we transfected venus (a fluorescent protein gene) into goat LSCs, selected with G418 and established a stable transfected cell line, named GLSC-V. These cells showed green fluorescence, and which could maintain for at least 3 months. GLSC-V also were positive for anti-P63 and anti-Integrinbeta1 antibody by immunofluorescent staining. We founded neither GLSC-V nor GLSCs expressed keratin3 (k3) and keratinl2 (k12). However, GLSC-V had higher levels in expression of p63, pcna and venus compared with GLSCs. Further, we cultivated the cells on denude amniotic membrane to construct tissue engineered fluorescent corneal epithelial sheets. Histology and HE staining showed that the constructed fluorescent corneal epithelial sheets consisted of 5-6 layers of epithelium. Only the lowest basal cells of fluorescent corneal epithelial sheets expressed P63 analyzed by immunofluorescence, but not superficial epithelial cells. These results showed that our constructed fluorescent corneal epithelial sheets were similar to the normal corneal epithelium in structure and morphology. This demonstrated that they could be transplanted for patents with corneal impair, also may provide a foundation for the study on the mechanisms of corneal epithelial cell regeneration after LSCT.
Animals ; Cell Culture Techniques ; methods ; Cell Line ; cytology ; Epithelium, Corneal ; cytology ; metabolism ; Fluorescent Antibody Technique, Indirect ; Goats ; Limbus Corneae ; cytology ; Stem Cell Transplantation ; Stem Cells ; cytology

OBJECTIVETo compare the three Anti-dsDNA antibody detecting test (IIF, ELISA, Farr) with 200 serum samples to evaluate which one has higher sensitivity and specificity.

METHODS200 serum samples including 120 serum samples of SLE, 20 serum samples of rheumatoid arthritis, 20 serum samples of MCTD, 20 serum samples of SS, 20 serum samples of PSS and 50 serum samples of healthy measured by IIF, Farr and ELISA.

RESULTSDetection the Anti-dsDNA antibody of the serum sample with the methods of IIF, ELISA and Farr. The positive percentage of Anti-dsDNA in SLE is 25%, 32% and 32%, while in RA is 0, 0 and 0; in PSS is 0, 0 and 5%; in SS is 0, 0 and 0; in healthy is 0, 0 and 0.

CONCLUSIONDetection the Anti-dsDNA antibody with two method in the same time, especially with IIF and ELISA, will heighten the positive rate than with single method and will be helpful for the diagnosis of SLE.

Antibodies, Antinuclear ; analysis ; immunology ; Case-Control Studies ; DNA ; immunology ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect ; Humans ; Immunologic Tests ; methods ; Lupus Erythematosus, Systemic ; diagnosis ; immunology ; Radioimmunoassay

OBJECTIVETo establish a method of indirect immunofluorescence (IIF) to measure DNA (mDNA)-associated autoantibodies to cell membrane, and to evaluate diagnostic value of the anti-mDNA antibodies in patients with juvenile systemic lupus erythematosus (SLE) in comparison with anti-dsDNA antibody.

METHODSForty-four children with SLE were enrolled in this study. As a control group, 30 children with other rheumatic diseases were also enrolled. Anti-mDNA and anti-dsDNA antibodies were measured by IIF. Anti-smooth muscle (Sm) antibodies were measured by immuno-double diffusion (ID) and IIF.

RESULTSOut of 44 juvenile SLE patients, 34 (77.27%) were seropositive for anti-mDNA, which was significantly higher than that of patients with other rheumatic diseases (20.00%, P<0.05). The sensitivity and specificity of anti-mDNA for juvenile SLE diagnosis were 77.27% and 80.00%, respectively. The positive predictive value and negative predictive value were 85.00% and 70.59%, respectively. The positive rate of anti-mDNA in SLE lacking of anti-dsDNA and anti-Sm antibodies were 68.00% (17/25) and 79.49% (31/39), respectively.

CONCLUSIONThe detection of anti-mDNA antibodies is useful for diagnosis of juvenile SLE, especially in patients who are negative for anti-dsDNA antibodies and anti-Sm antibodies.

Adolescent ; Antibodies, Antinuclear ; analysis ; Case-Control Studies ; Cell Membrane ; immunology ; Child ; Female ; Fluorescent Antibody Technique, Indirect ; methods ; Humans ; Lupus Erythematosus, Systemic ; immunology ; Male ; Predictive Value of Tests ; Sensitivity and Specificity

BACKGROUND AND PURPOSE: Cutaneous nerve biopsies based on two-dimensional analysis have been regarded as a creditable assessment tool for diagnosing peripheral neuropathies. However, advancements in methodological imaging are required for the analysis of intact structures of peripheral nerve fibers. A tissue-clearing and labeling technique facilitates three-dimensional imaging of internal structures in unsectioned, whole biological tissues without excessive time or labor costs. We sought to establish whether a tissue-clearing and labeling technique could be used for the diagnostic evaluation of peripheral neuropathies. METHODS: Five healthy individuals and four patients with small-fiber neuropathy (SFN) and postherpetic neuralgia (PHN) were prospectively enrolled. The conventional methods of indirect immunofluorescence (IF) and bright-field immunohistochemistry (IHC) were adopted in addition to the tissue-clearing and labeling method called active clarity technique-pressure related efficient and stable transfer of macromolecules into organs (ACT-PRESTO) to quantify the intraepidermal nerve-fiber density (IENFD). RESULTS: The mean IENFD values obtained by IF, bright-field IHC, and ACT-PRESTO in the healthy control group were 6.54, 6.44, and 90.19 fibers/mm², respectively; the corresponding values in the patients with SFN were 1.99, 2.32, and 48.12 fibers/mm², respectively, and 3.06, 2.87, and 47.21 fibers/mm², respectively, in the patients with PHN. CONCLUSIONS: This study has shown that a tissue-clearing method provided not only rapid and highly reproducible three-dimensional images of cutaneous nerve fibers but also yielded reliable quantitative IENFD data. Quantification of the IENFD using a tissue-clearing and labeling technique is a promising way to improve conventional cutaneous nerve biopsies.
Biopsy ; Fluorescent Antibody Technique, Indirect ; Humans ; Imaging, Three-Dimensional ; Immunohistochemistry ; Methods ; Nerve Fibers ; Neuralgia, Postherpetic ; Peripheral Nerves ; Peripheral Nervous System Diseases ; Prospective Studies

Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI< or =50), and 76 out of 82 (92.7%) sera in chronic phase of infection showed high avidity index (AI>60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.
Antibodies, Protozoan/*blood ; *Antibody Affinity ; Clinical Laboratory Techniques/*methods ; Enzyme-Linked Immunosorbent Assay/methods ; Fluorescent Antibody Technique, Indirect ; Humans ; Immunoglobulin G/*blood ; Immunoglobulin M/blood ; Iran ; Parasitology/*methods ; Toxoplasmosis/*diagnosis

Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI< or =50), and 76 out of 82 (92.7%) sera in chronic phase of infection showed high avidity index (AI>60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.
Antibodies, Protozoan/*blood ; *Antibody Affinity ; Clinical Laboratory Techniques/*methods ; Enzyme-Linked Immunosorbent Assay/methods ; Fluorescent Antibody Technique, Indirect ; Humans ; Immunoglobulin G/*blood ; Immunoglobulin M/blood ; Iran ; Parasitology/*methods ; Toxoplasmosis/*diagnosis

To study the correlation between ELISA and IFA tests in detection of ALV-A/B antibody in chicken sera, ELSA S/P values and IFA titers for different serum samples were measured and statistically analyzed. The results indicated that there was a strong positive correlation between ELISA S/P values and IFA titers (r = 0.97435, P < 0.001). Because the positive correlation between ELISA and IFA was so strong and antibody positive rates were identical in two tests, it suggested that IFA could be used as a alternative method to replace ELISA kit when only limited numbers of samples to be tested to reduce the cost and increase the sensitivity.
Animals ; Antibodies, Viral ; blood ; immunology ; Avian Leukosis ; diagnosis ; immunology ; virology ; Avian Leukosis Virus ; classification ; immunology ; isolation & purification ; Cell Line ; Chickens ; Enzyme-Linked Immunosorbent Assay ; methods ; Fluorescent Antibody Technique, Indirect ; methods ; Poultry Diseases ; diagnosis ; immunology ; virology ; Species Specificity