Correlation of Treponemal Chemiluminescent Microparticle Immunoassay Screening Test Signal Strength Values With Reactivity of Confirmatory Testing.

BACKGROUND: Automated chemiluminescent microparticle immunoassays (CMIAs) are the most common first step at high-volume laboratories for syphilis screening. If the initial screening test is reactive, 1 more treponemal test is required, resulting in increased cost. In this multicenter study, we aimed to determine the correlation between the CMIA signal-to-cutoff ratio (S/Co) and the confirmatory tests to reduce unnecessary confirmatory testing. METHODS: Eight hospitals from 5 provinces participated in this study. All laboratories used Architect Syphilis TP CMIA (Abbott Diagnostics, Abbott Park, IL) for initial screening. Treponema pallidum hemagglutination (TPHA), rapid plasma reagin (RPR), and fluorescent treponemal antibody absorption (FTA-ABS) were used as confirmatory tests according to the reverse or European Centre for Disease Prevention and Control algorithms. A receiver operating characteristic analysis was used to determine the optimal S/Co ratio to predict the confirmation results. RESULTS: We evaluated 129,346 serum samples screened by CMIA between January 2018 and December 2020. A total of 2468 samples were reactive; 2247 (91%) of them were confirmed to be positive and 221 (9%) were negative. Of the 2468 reactive specimens, 1747 (70.8%) had an S/Co ratio ≥10.4. When the S/Co ratios were ≥7.2 and ≥10.4, the specificity values were determined to be 95% and 100%, respectively. In a subgroup of 75 CMIA-positive patients, FTA-ABS was performed and 62 were positive. Among these FTA-ABS-positive patients, 24 had an S/Co ratio <10.4, and negative TPHA and RPR. CONCLUSIONS: We propose a potentially cost-effective reverse screening algorithm with a treponemal CMIA S/Co ratio ≥10.4, obviating the need for secondary treponemal testing in about 71% of the screening-reactive samples. This would substantially reduce the confirmatory testing volume and laboratory expenses. However, in high-risk group patients with CMIA positive results, S/Co ratio <10.4, and negative TPHA and RPR, FTA-ABS may be used for confirmation.

Evaluation of the Diagnostic Algorithms for Serodiagnosis of Syphilis.

We analyzed the performance parameters of the traditional and reverse algorithms to determine which is more convenient for serodiagnosis of syphilis. In total, 4,789 serum samples were obtained from a cross-sectional study. Venereal Disease Research Laboratory (VDRL), Treponema pallidum hemagglutination assay (TPHA), and chemiluminescent microparticle immunoassay (CMIA) tests were performed on each serum sample. In case of discordance between results, TPHA was applied as a second treponemal test. Overall, 207 patients were serodiagnosed with syphilis. Among the 4,789 samples tested, 125 (2.6%) and 206 (4.3%) were positive using the traditional and reverse algorithms, respectively. The missed diagnosis rate of the traditional algorithm was 42.5%. The reverse algorithm had a higher sensitivity than that of the traditional algorithm. The sensitivity levels of the traditional and reverse algorithms were 57.49% and 99.85% respectively. The false positivity rate of the reverse algorithm was 0.02%.

Safer Blood Supply for Transfusion: Which Algorithm Should Be Used to Determine Occult Hepatitis B Infection in Blood Donors?

BACKGROUND: Transfusion-transmitted hepatitis B virus continues to be a problem despite its significantly reduced prevalence. In this study, in addition to screening for the presence of HBsAg in donors' blood, anti-HBc and anti-HBs markers were investigated using the chemiluminescence immunoassay (CLIA) method, and real-time PCR was used to detect HBV DNA. METHODS: The study's material involved serum samples of 4,073 blood donors. HBsAg, anti-HBs, anti-HBc tests were undertaken using the CLIA method, and HBV DNA's presence was investigated using the real-time PCR method. RESULTS: HBsAg and anti-HBc tests were negative in 3,331 (81.78%) and positive in 37 (0.90%). For the remaining 705 (17.30%), HBsAg was negative and anti-HBc was positive. According to the results of the anti-HBs test for these samples, HBsAg negativity and anti-HBc and anti-HBs positivity were found in 619 samples (15.19%), while 86 samples (2.11%) were negative for HBsAg and anti-HBs but positive for anti-HBc (isolated anti-HBc positivity). ID-HBV DNA real-time PCR tests were performed on 86 samples. None of the samples was positive for HBV DNA. CONCLUSIONS: Recommended tests for screening occult HBV infection include anti-HBc, anti-HBs, and/or HBV DNA. Anti-HBc screening may result in loss of donors and blood products, particularly in countries with moderate endemicity of HBV, such as Turkey.

Comparison of non-invasive tests with invasive tests in the diagnosis of celiac disease.

BACKGROUND/AIMS: Today, invasive diagnostic tests are necessary for definite diagnosis of adult celiac disease (CD). However, in selected children patients, the need for invasive tests is ceased. In this study, we evaluated adult patients according to the ESPGHAN (European Pediatric Gastroenterology Hepatology and Nutrition Society) criteria. METHODS: Thirty-nine patients (aged 17-66) with symptoms of CD were included. Serum samples were tested for total IgA, tTG-IgA (antitissue transglutaminase), tTG-IgG, DGP-IgA (antideamidated gliadin peptide), DGP-IgG, and EMA (endomysial antibodies). HLA-DQ typing was studied with PCR-SSP (sequence-specific primers) method. Biopsy samples were evaluated according to Marsh scoring. RESULTS: In CD patients, 71.4% (15/21) of the patients were diagnosed without biopsy according to the EPSGHAN criteria but when ESPGHAN's IgA tTG threshold value for children was taken into consideration (>200 IU/mL), the sensitivity decreased to 81%. Celiac disease diagnosed and control groups were compared in terms of HLA tissue types. DQ2.5 homozygous or DQ2.5/DQ2.2 was significantly higher in CD group, and DQ2- or DQ8-negative HLA tissue type was significantly higher in control group. CONCLUSION: When serological tests, HLA typing, and clinical symptoms are all in favor of CD, biopsy may not be performed in selected adult CD patients.

[Investigation of the diagnostic value of anti-dense fine speckled 70/lens epithelium derived growth factor p75 autoantibody for autoimmune diseases]. / Anti-dense fine speckled 70/lens epithelium derived growth factor p75 otoantikorunun otoimmün hastaliklarda klinik taniya katkisinin arastirilmasi.

Antinuclear antibodies (ANA) are the autoantibodies that are produced against nuclear antigens in the cell nucleus and/or cytoplasm, and are one of the important diagnostic criteria in systemic autoimmune rheumatic diseases (SARD). Until today, several methods have been developed for detecting ANA's. However, indirect immunofluorescence (IIF) technique, that is also known as one of the oldest methods, is still the most commonly used one. Typically, anti-dense fine speckled 70/Lens epithelium derived growth factor p75 (anti-DFS70/LEDGF p75) autoantibody can be detected via IIF method where in HEp-2 (human larynx carcinoma) cells are used. The dense fine speckled (DFS) pattern method can be masked and remain unnoticed by the IIF method when it exists with the other ANA. Anti-DFS70 autoantibodies seldomly appear in SARD patients compared to healthy individuals. Moreover, these antibodies may appear in different chronic inflammatory conditions like interstitial cystitis, chronic fatigue syndrome, atopic dermatitis and Vogt-Koyanagi-Harada syndrome. The aim of this study was to determine the frequency of anti-DFS70 autoantibodies by immunblot (IB) method in patients sera with and without DFS70 staining pattern by IIF and to determine if the presence of anti-DFS70 has a clinical impact when included in ANA testing algorithm. In our study, a total of 60 patients' sera in which DFS pattern was defined by IIF method and 67 patients' sera in which other patterns observed were included in the study and anti-DFS70 autoantibody was investigated by IB method in these sera. In 67 patient samples which have shown the other patterns three (4.5%) samples were determined to be anti-DFS70 positive by IB. In 55 patients who were determined to have IIF-DFS pattern (+)/IB anti-DFS70 (+), 6 (11%) were diagnosed as SARD and the other antinuclear antibodies (ANA) were found as negative by IB. In the other group with the other ANA patterns detected, none of the SARD-diagnosed 22 patients had shown anti-DFS70 by IB method. Sixteen (26.6%) samples in the group that was positive for the IIF-DFS pattern were obtained from rheumatology and physical therapy and rehabilitation clinics, 32 (47.7%) samples were from the group in which other patterns observed and were also obtained from those clinics. DFS pattern was detected significantly more frequent in the samples from other clinics in comparison to the samples from rheumatology and physical therapy and rehabilitation clinics (p= 0.018). In our study, it was concluded that DFS pattern can be defined by IIF method by only specialists, however, since homogeneous-like and mixed patterns can be confused especially in low titers, there is a need for a second well-validated immunological test that could detect anti-DFS70 auto-antibody.

Investigation of an algorithm for anti HCV EIA reactivity in blood donor screening in Turkey in the absence of nucleic acid amplification screening.

PURPOSE: In this study we aimed to propose an algorithm for initial anti HCV EIA reactive blood donations in Turkey where nucleic acid amplification tests are not yet obligatory for donor screening. METHODS: A total of 416 anti HCV screening test reactive donor samples collected from 13 blood centers from three cities in Turkey were tested in duplicate by Ortho HCV Ab Version 3.0 and Radim HCV Ab. All the repeat reactive samples were tested by INNO-LIA HCV Ab 3.0 or Chiron RIBA HCV 3.0 and Abbott Real Time HCV. Intra-assay correlations were calculated with Pearson r test. ROC analysis was used to study the relationship between EIA tests and the confirmatory tests. RESULTS: The number of repeat reactive results with Ortho EIA were 221 (53.1%) whereas that of microEIA, 62 (14.9%). Confirmed positivity rate was 14.6% (33/226) by RIBA and 10.6% (24/226) by NAT. Reactive PCR results were predicted with 100% sensitivity and 95% specificity with S/CO levels of 8.1 with Ortho EIA and 3.4 with microEIA. CONCLUSIONS: Repeat reactivity rates declined with a second HCV antibody assay. Samples repeat reactive with one HCV antibody test and negative with the other were all NAT negative. All the NAT reactive samples were RIBA positive. None of the RIBA indeterminate or negative samples were NAT reactive. Considering the threshold values for EIA kits determined by ROC analysis NAT was decided to be performed for the samples above the threshold value and a validated supplemental HCV antibody test for the samples below.

Antioxidant role of selenium in rats with experimental acute otitis media.

The aim of this prospective experimental animal study was to determine whether selenium had a protective effect on oxidative stress in rats with acute otitis media, by measuring the alterations of antioxidant parameters and lipid peroxidation on days 4 and 10 after inoculation into the middle ear. Streptococcus pneumoniae was inoculated into the middle ear cavities of 32 rats in animal laboratory of a tertiary medical center. Group 1 served as the control group and the animals were administered 1.5 ml/day saline. Group 2 received 0.2 mg/kg/day oral selenium for 10 days. The blood samples of each group were obtained on post-inoculation days 4 and 10. The levels of thiobarbituric acid reactive substances, albumin, total sulphydryl, superoxide dismutase and glutathione peroxidase were investigated. Day 10 level of thiobarbituric acid reactive substance in group 2 was lower than the day 4 level of the same substance in the control group. Although glutathione peroxidase and superoxide dismutase levels significantly decreased starting from 4th day until 10th day in group 1, their levels increased in group 2. Day 10 levels of albumin and total sulphydryl in group 1 were significantly higher than day 4 levels in group 2. We found that selenium supplementation for 10 days decreased thiobarbituric acid reactive substances and increased glutathione peroxidase and superoxide dismutase levels when compared to the control group. We believe that selenium supplementation may be beneficial to prevent the clinical sequelae and recurrence of otitis media.

Detection of hepatitis B virus deoxyribonucleic acid using real-time polymerase chain reaction method in pooled-plasma samples of Turkish blood donors.

BACKGROUND: The extent and the number of routine tests performed for blood donor screening to avoid infections transmitted through blood transfusion have been gradually increasing worldwide and is determined nationally. Following the publication of the new "blood and blood components regulation", the blood banking and transfusion system is through a reorganization stage in Turkey. The national guideline including the donor screening algorithms is to be published which requires national data to be created. The aim of this study is to investigate HBV DNA in pooled plasma samples of blood donors in Turkey, which is a middle endemicity country for HBV infection. STUDY DESIGN AND METHODS: Presence of HBV DNA was investigated using real-time polymerase chain reaction (RT-PCR) method in 187 pooled plasma samples prepared from 4484 blood donors, whose screening tests were found to be negative. The seropositivity for HBsAg of the blood donors in the study blood center is 2.2%. RESULTS: The rate of false-positivity of the RT-PCR method was found to be 1.6% for the mini pools and 0.04% for the individual blood donors. HBV DNA was not detected in any of the donor bloods. CONCLUSION: The hospital blood centers in Turkey still have a high proportion of first time donors and replacement donors; also seropositivity of HBsAg in Turkish blood donors is high compared to Europe and US. Our data pointed to the high false positivity rate of RT PCR method which needs to be evaluated in creating national donor screening algorithms.

[Comparison of the methods used for the detection of antinuclear antibodies]. / Antinükleer antikorlarin saptanmasinda kullanilan yöntemlerin karsilastirilmasi.

The production of one or more autoantibodies in the majority of rheumatic diseases is a common clinical finding. Indirect immunofluorescent antibody (IFA) test is the former and widely used method in detecting autoantibodies. Recently, commercial enzyme immunoassays (EIA) and immunoblot (IB) assays are available for the routine laboratories. The aim of this study was to compare the efficacies of these methods in 121 sera samples which were collected from 46 male and 75 female patients, of whom antinuclear antibody (ANA) testing were requested by clinicians. All the samples were simultaneously studied by IFA with HEp-2 and Crithidia lucillae cells, and by two different commercial kits of EIA and IB, and the results were evaluated. When IFA is accepted as reference method, the sensitivities and specificities of the other methods were found as follows, respectively; 82-100% and 84-100% for ANA-EIA, 48-54% and 98-100% for ANA-IB, 66-100% and 97-98% for anti-dsDNA-EIA, and 50-66% and 86-100% for anti-dsDNA-IB. The agreement rates of ANA-EIA, ANA-IB, anti-dsDNA-EIA and anti-dsDNA-IB methods with IFA were detected as 82-90%, 74%, 96-97%, and 84-98%, respectively. As a result, it may be concluded that IFA test should be used as a primarily test for the detection of ANA and anti-dsDNA autoantibodies, while EIA and IB methods are useful for antigen differentiation and confirmation of the results.