Performance evaluation of the Elecsys syphilis assay for the detection of total antibodies to Treponema pallidum

Alternative Splicing in Cancer and Immune Cells

Splicing is a phenomenon enabling the excision of introns from pre-mRNA to give rise to mature mRNA. All the 20,000 genes of the human genome are concerned by this mechanism. Nevertheless, it is estimated that the proteome is composed of more than 100,000 proteins. How to go from 20,000 genes to more than 100,000 proteins? Alternative splicing (AS) is in charge of this diversity of proteins. AS which is found in most of the cells of an organism, participates in normal cells and in particular in immune cells, in the regulation of cellular behavior. In cancer, AS is highly dysregulated and involved in almost all of the hallmarks that characterize tumor cells. In view of the close link that exists between tumors and the immune system, we present in this review the literature relating to alternative splicing and immunotherapy. We also provide a global but not exhaustive view of AS in the immune system and tumor cells linked to the events that can lead to AS dysregulation in tumors.

Data on the Relationships of Signal-To-Cutoff Ratios of Elecsys HIV Antigen/Antibody and Elecsys Syphilis Assays to Subsequent Confirmatory Testing at an Academic Medical Center

Immunoassays are widely used as screening tests for HIV and syphilis in clinical, public health, and research settings. For syphilis, immunoassays are used in 'reverse syphilis algorithms' that start with treponemal tests such as syphilis IgG or syphilis total antibodies for the initial screen. Many screening immunoassays for HIV and syphilis use signal-to-cutoff (S/CO) values for determining positivity, with a cutoff value such as 1.0 differentiating positive from negative. Published literature indicates that the S/CO value often correlates with the likelihood of subsequent confirmation of HIV and syphilis infections, with low S/CO values barely exceeding the cutoff more likely to represent false positive screens. The data in this article present results from the Roche Diagnostics Elecsys HIV combi PT Assay and the Elecsys Syphilis Assay. The data include 19,368 syphilis total antibody screening results on 15,764 unique patients and 28,952 HIV screening results on 24,556 unique patients, S/CO values, clinical area where testing was ordered, sex, and age. For samples with positive syphilis total antibody screens, the data also include results of RPR (the immediate next step in the reverse algorithm), Treponema pallidum particle agglutination (TP-PA; for those samples in which RPR was non-reactive in the testing cascade), and clinical information and other testing related to diagnosis of syphilis. For positive HIV screens, the data also include HIV antibody differentiation results, HIV-1 PCR or HIV-2 results results (if performed), and clinical information related to diagnosis of HIV. The distributions of S/CO values relative to confirmation status were analyzed.

Azithromycin vs penicillin G benzathine for early syphilis: A meta-analysis of randomized controlled trials

Syphilis is a very serious infection that causes acute cutaneous manifestations. Penicillin is the gold standard for treating syphilis. This meta-analysis was conducted based on self-published randomized controlled trials (RCTs) data to compare the efficacy of azithromycin with penicillin for treating syphilis. RCTs on azithromycin vs penicillin for the treatment of syphilis were retrieved from the Cochrane Library, MEDLINE, EBSCO, Embase, Ovid, and other databases, and the estimated risk ratio (RR) and 95% confidence interval (CI) were used to study the following outcome indicators: 3-month response rate, 6-month response rate, 12-month response rate, recurrence rate, serum fixation rate, and failure rate. This meta-analysis included seven RCTs involving 639 subjects (of whom 335 were treated with azithromycin and 304 were treated with penicillin). There was no significant difference in the 3-month response rate (RR = 0.97, 95% CI: 0.79-1.19), 6-month response rate (RR = 1.01, 95% CI: 0.85-1.20), 12-month response rate (RR = 1.02, 95% CI: 0.97-1.09), serum fixation rate (RR = 0.71, 95% CI: 0.24-2.12), and failure rate (RR = 0.62, 95% CI: 0.33-1.16). In summary, there is no evidence in the literature that azithromycin is less effective than penicillin for treating syphilis.

Neurosyphilis cerebrospinal fluid findings in patients with ocular syphilis

Purpose: To evaluate neurosyphilis cerebrospinal fluid (CSF) findings and initial ophthalmic manifestations in patients with syphilitic uveitis.Methods: We retrospectively reviewed the records of CSF analysis of 14 patients with syphilitic uveitis with treponemal analysis - chemiluminescent immunoassay and TPHA- and non-treponemal analysis - Rapid Plasma Reagin test - RPR.Results: 86% were males and 43% HIV+. Ocular signs of syphilis lead to the diagnosis of syphilis in 78% of patients. Typical syphilitic uveitis presentations included: acute syphilitic posterior placoid chorioretinitis (50% of patients), retinitis (21% of patients) and punctate inner retinitis (7% of patients). 57% of patients had definite neurosyphilis by the CDC criteria, while 71% had CSF abnormalities suggestive of central nervous system involvement.Conclusion: Based on international guidelines, the frequent CSF abnormalities found in syphilitic uveitis patient supports the diagnosis of neurosyphilis in a majority of patients.

Comparison of three syphilis algorithms in West China

OBJECTIVE

The study was designed to analyze three different algorithms with the implementation of treponemal tests for detecting suspected syphilis in west China where no syphilis algorithms guideline exists.

METHODS

We retrospectively collected data to reanalyze three syphilis testing algorithms: the classical reverse algorithm, and two options of syphilis screening in European syphilis guideline. The kappa (κ) coefficients were used to compare the concordance between algorithms using different syphilis assays during two periods. A receiver operating characteristic curve was used to determine the optimal S/CO ratios of InTec EIA or Lumipulse® G TP-N assay (CLIA) to predict confirmatory TPPA results.

RESULTS

The agreements between the reverse algorithm and the EU option 1 algorithms were perfect irrespective of EIA or CLIA used (all κ > 0.9). But the agreements between the EU option 2 algorithms and reverse or EU option 1 were not good (κ < 0.4). >50% cases confirmed syphilis infections by reverse or EU option 1 algorithm were missed by EU option 2. There is no very need for a confirmatory TPPA assay in EU Option 1 when S/CO is above 6.12 for CLIA (3.67 for EIA). The false-positive rate was 0.26% above this cutoff level.

CONCLUSIONS

EU Option 1, involving a reactive TT, followed by another TT of a different type and a quantitative NTT if second TT is positive, which is the same as the 2015 UK syphilis algorithm, is recommended. We also propose that when S/CO of the CLIA or EIA is high enough, TPPA confirmation can be omitted from the testing algorithm, and costs would be significantly reduced.

Evaluation of the Elecsys Syphilis Immunoassay for Detection of Syphilis in Populations at Risk of Disease in the US and Argentina

BACKGROUND

The Elecsys® syphilis immunoassay is an automated, qualitative immunoassay that uses a double-antigen sandwich format to detect antibodies to Treponema pallidum in human serum and plasma. We aimed to validate performance of the immunoassay in various populations at risk for syphilis infection in the US and Argentina.

METHODS

Samples were obtained for a number of study cohorts, including participants from routine syphilis testing at high or low risk for syphilis, HIV-positive patients, pregnant women, and patients in various stages of syphilis infection. The primary objective was to validate the Elecsys syphilis immunoassay by comparing it with a composite testing algorithm using US Food and Drug Administration (FDA)-approved tests, including the predicate IMMULITE 2000 syphilis screening assay, the rapid plasma reagin, and the T. pallidum particle agglutination assay.

RESULTS

Complete algorithm testing was performed on all 2660 collected samples. Acceptable precision was demonstrated in all samples. Comparison of the Elecsys syphilis immunoassay with the final syphilis status for all samples yielded a diagnostic sensitivity of 99.5% (95% CI, 98.21-99.94) and a diagnostic specificity of 99.2% (95% CI, 98.69-99.49). Overall, the lower limit of the 95% CIs for sensitivity and specificity met the expected performance of ≥95%.

CONCLUSION

This is the first study that confirms the high sensitivity and specificity of the Elecsys syphilis immunoassay in US and Argentinian cohorts and highlights the assay's usefulness as an alternative to current tests for the diagnosis of syphilis infection in a broad range of participant cohorts.

Evaluation of the Elecsys syphilis immunoassay for routine screening of serum samples in China

We compared the performance of the Roche Diagnostics Elecsys immunoassay for the detection of Treponema pallidum specific antibodies in patient serum samples with that of the Abbott Laboratories Architect chemiluminescent microparticle immunoassay and the InTec and KHB enzyme-linked immunosorbent assays, which are commonly used in China. We tested 13,767 serum samples collected from 13 independent laboratories throughout China, which included samples from 999 previously confirmed syphilis cases and 158 'borderline' samples previously identified using the Architect, InTec, and KHB tests. The Mikrogen Syphilis Immunoblot was used to confirm positive test results. The consistency between the four different assays was 100%. The sensitivity of Elecsys immunoassay was 100% versus 98.26% for Architect, 99.11% for InTec; and 98.56% for KHB. The specificity of the Elecsys immunoassay was 99.81% versus 99.74% for Architect; 99.93% versus 99.80% for InTec; and 99.85% versus 99.77% for KHB. For borderline samples, the Elecsys immunoassay yielded no false-negative results and fewer false-positive results, compared to the other tests. Considering the ease-of-use, automation, high speed, and high throughput capacity of the Elecsys assay, the higher sensitivity and specificity indicate it is superior for routine screening of serum samples for syphilis diagnosis.

Evaluation of Elecsys Syphilis Assay for Routine and Blood Screening and Detection of Early Infection

Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient populations, at seven independent laboratories. The samples included routine diagnostic samples, blood donation samples, samples from patients with confirmed HIV infections, samples from living organ or bone marrow donors, and banked samples, including samples previously confirmed as syphilis positive. This study also investigated the seroconversion sensitivity of the assay. With a total of 1,965 syphilis-negative routine diagnostic samples and 5,792 syphilis-negative samples collected from blood donations, the Elecsys Syphilis assay had specificity values of 99.85% and 99.86%, respectively. With 333 samples previously identified as syphilis positive, the sensitivity was 100% regardless of disease stage. The assay also showed 100% sensitivity and specificity with samples from 69 patients coinfected with HIV. The Elecsys Syphilis assay detected infection in the same bleed or earlier, compared with comparator assays, in a set of sequential samples from a patient with primary syphilis. In archived serial blood samples collected from 14 patients with direct diagnoses of primary syphilis, the Elecsys Syphilis assay detected T. pallidum antibodies for 3 patients for whom antibodies were not detected with the Architect Syphilis TP assay, indicating a trend for earlier detection of infection, which may have the potential to shorten the time between infection and reactive screening test results.

Clinical Evaluation of Fully Automated Elecsys® Syphilis Assay for the Detection of Antibodies of Treponema pallidum

OBJECTIVE

The resurgence of syphilis in recent years has become a serious threat to the public health worldwide, and the serological detection of specific antibodies against Treponema pallidum (TP) remains the most reliable method for laboratory diagnosis of syphilis. The performance of the Elecsys^® Syphilis assay, a brand new electrochemiluminescene immunoassay (ECLIA), was assessed by large amounts of samples in this study.

METHODS

In comparison with InTec assay, the Elecsys^® Syphilis assay was evaluated in 146 preselected samples from patients with syphilis, 1803 clinical routine samples, and 175 preselected samples from specific populations with reportedly increased rates of false-positive syphilis test results. Discrepancy samples must be investigated by Mikrogen Syphilis recomline assay.

RESULTS

There was an overall agreement of 99.58% between two assays (Kappa = 0.975). The sensitivity and specificity of the Elecsys^® Syphilis assay were 100.0% (95% CI, 96.8-100.0%) and 99.8% (95% CI, 99.5-100.0%), respectively. The Elecsys syphilis assay displays better sensitivity (100%), specificity (99.8%), PPV (98.7%), and NPV (100%) in 2124 samples enrolled, compared with the InTec assay.

CONCLUSION

Considering the excellent ease of use and automation, high throughput, and its superior sensitivity, especially in primary syphilis, the Elecsys^® Syphilis assay could represent an outstanding choice for screening of syphilis in high-volume laboratories. However, more attention was still needed, or the results must be confirmed by other treponemal immunoassays. The new Elecsys^® Syphilis assay is applied to patients with malignant neoplasm or HIV infection.

Comparison of performance of two Treponema pallidum automated chemiluminescent immunoassays in blood donors

The recrudescence of syphilis is leading to the development of new serological tests. The goal of this study was to compare the performance of the more recent Elecsys Syphilis assay, the Electro Chemiluminescence Immunoassay (ECLIA), with the former Architect Syphilis TP assay, the Chemiluminescent Microparticle Immunoassay (CMIA), for the detection of antibodies against Treponema pallidum in blood donors. Serum samples of 5543 voluntary blood donors were screened in parallel with two tests. All repeatedly reactive (RR) samples by one or both assays were further analysed for confirmation by immmunoblot INNO-LIA and TPHA. Of 32 RR samples by CMIA, 21 were confirmed positive; of 21 RR samples by ECLIA, 20 were confirmed positive. The sensitivities of CMIA and ECLIA were 100% and 95.24% (95% CI = 85.71-100), respectively, not significant (p > 0.05). The specificity and predictive positive value (PPV) of CMIA were 99.86% (95% CI = 99.74-99.94) and 72.41%, respectively, while the specificity and PPV of ECLIA were both 100%, being statistically significant (p = 0.01 for both). The overall agreement was 99.80% and the Cohen's kappa coefficients was 0.79. In conclusion, the recent Elecsys Syphilis assay could represent another reliable assay for blood donor screening.

Meta-analysis of ceftriaxone compared with penicillin for the treatment of syphilis

Penicillin is the gold standard for treating syphilis. However, allergic reactions, poor drug tolerance and limited efficacy in patients remain a challenging problem. The objective of this meta-analysis was to compare the efficacy of ceftriaxone and penicillin based on data obtained from published randomised controlled trials (RCTs). The Cochrane Library, Medline, EBSCO, EMBASE and Ovid databases were searched for RCTs of ceftriaxone vs. penicillin for the treatment of syphilis. Estimated risk ratios (RRs) and 95% confidence intervals (CIs) were used to investigate the following outcome measures: 3-month response rate; 6-month response rate; 12-month response rate; relapse rate; serofast rate; and failure rate. Seven RCTs involving 281 participants (159 patients who received ceftriaxone and 122 patients who received penicillin) were included in the meta-analysis. There were no significant differences in 3-month response rate (RR=1.12, 95% CI 0.89-1.42), 6-month response rate (RR=1.02, 95% CI 0.75-1.38), 12-month response rate (RR=1.04, 95% CI 0.82-1.32), relapse rate (RR=0.91, 95% CI 0.45-1.84), serofast rate (RR=0.69, 95% CI 0.22-2.12) or failure rate (RR=0.66, 95% CI 0.03-15.76) in patients treated with ceftriaxone compared with those treated with penicillin. In conclusion, there is no evidence in the literature that ceftriaxone is less efficient than penicillin.

Evaluation of the HISCL Anti-Treponema pallidum Assay as a Screening Test for Syphilis

The resurgence of syphilis in recent years has become a serious threat to public health worldwide, and the serological detection of specific antibodies against Treponema pallidum remains the most reliable method for laboratory diagnosis of syphilis. This study examined the performance of the recently launched HISCL anti-Treponema pallidum (anti-TP) assay as a screening test for syphilis in a high-volume laboratory. The HISCL anti-TP assay was tested in 300 preselected syphilis-positive samples, 704 fresh syphilis-negative samples, 48 preselected potentially interfering samples, and 30 "borderline" samples and was compared head to head with the commercially available Lumipulse G TP-N. In this study, the HISCL anti-TP assay was in perfect agreement with the applied testing algorithms with an overall agreement of 100%, comparable to that of Lumipulse G TP-N (99.63%). The sensitivity and specificity of the HISCL anti-TP assay were 100% (95% confidence interval [CI], 98.42% to 100%) and 100% (95% CI, 99.37% to 100%), respectively. Considering the excellent ease of use and automation, high throughput, and its favorable sensitivity and specificity, the HISCL anti-TP assay may represent a new choice for syphilis screening in high-volume laboratories.