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Andrej Trampuz - One of the best experts on this subject based on the ideXlab platform.
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is the enzyme linked immunosorbent assay more accurate than the lateral flow Alpha Defensin test for diagnosing periprosthetic joint infection
Clinical Orthopaedics and Related Research, 2018Co-Authors: Irene Katharina Sigmund, Katsiaryna Yermak, Andrej Trampuz, Carsten Perka, Nora RenzAbstract:BACKGROUND: Alpha Defensin was proposed as a new biomarker in synovial fluid for the diagnostic workup of failed joint prostheses. To our knowledge, no comparative study of the performance of the quantitative enzyme-linked immunosorbent assay (ELISA) and qualitative lateral flow Alpha Defensin test has been reported. QUESTIONS/PURPOSES: (1) Using the proposed European Bone and Joint Infection Society (EBJIS) criteria for defining periprosthetic joint infection (PJI), is there a difference in the diagnostic accuracy of quantitative ELISA and qualitative lateral flow Alpha Defensin tests? (2) Is there a difference in the performance of the two Alpha Defensin tests when using three definition classification systems (Musculoskeletal Infection Society [MSIS], Infectious Diseases Society of America [IDSA], and proposed EBJIS)? METHODS: In this retrospective study of samples collected earlier as part of a related longitudinal study, we included patients in whom aspiration of the prosthetic hip or knee was performed as routine investigation before every revision arthroplasty. Between October 2016 and April 2017, a total of 73 patients were eligible for inclusion. As a result of an insufficient fluid volume for analysis (< 5 mL), two patients were excluded. Among the 71 patients in the final analysis, 54 had a knee and 17 a hip arthroplasty. Using the proposed EBJIS criteria, PJI was diagnosed in 22 patients (31%) and aseptic failure in 49 (69%). The Alpha Defensin ELISA and lateral flow tests were performed in synovial fluid. Patients were classified as having PJI or aseptic failure using the MSIS, the IDSA, and the proposed EBJIS criteria. Sensitivity and specificity of ELISA and the lateral flow Alpha Defensin test were calculated. Based on receiver operating characteristic analysis, area under the curve values were compared. RESULTS: When measured against the proposed EBJIS criteria, the sensitivity of Alpha Defensin ELISA and the lateral flow test was low and not different from one another with the numbers available at 50% (95% confidence interval [CI], 31%-69%) and 46% (95% CI, 27%-65%; p = 0.857), respectively, whereas both methods showed high specificity (98% [95% CI, 88%-100%]; p = 1.000). For sensitivity, the highest values were seen when compared against the MSIS criteria (ELISA: 85% [95% CI, 56%-97%], lateral flow: 77% [95% CI]; p = 0.871), intermediate with IDSA criteria (ELISA: 73% [95% CI, 48%-89%], lateral flow: 67% [95% CI]; p = 0.867), and lowest with proposed EBJIS criteria (ELISA: 50% [95% CI, 31%-69%], lateral flow: 46% [95% CI]; p = 0.763). Specificity, however, was high regardless of the criteria used, where ELISA and lateral flow produced results that were not different (MSIS: 98% [95% CI, 90%-100%], IDSA: 98% [95% CI, 90%-100%], EBJIS: 98% [95% CI, 88%-100%]; p = 1.000). The area under the curve of Alpha Defensin ELISA and the lateral flow test was similar, regardless of the definition criteria used (EBJIS: p = 0.566; IDSA: p = 0.425; MSIS: p = 0.339). CONCLUSIONS: There is no difference between the quantitative and qualitative Alpha Defensin test for confirmation of PJI, irrespective of applied definition criteria. Having the advantage of providing results within 10 minutes without the need for a laboratory facility, the qualitative test may be of interest in the intraoperative setting, however, at a cost of higher test expense. LEVEL OF EVIDENCE: Level I, diagnostic study.
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Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection not a screening but a confirmatory test
Journal of Bone and Joint Surgery American Volume, 2018Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Background:Determination of Alpha Defensin in synovial fluid has shown promising results for diagnosing periprosthetic joint infection (PJI). The purposes of our study were to assess the performance of Alpha Defensin lateral flow (ADLF) test for the diagnosis of acute and chronic PJI using 3 classif
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comparison of quantitative and qualitative Alpha Defensin test for diagnosing periprosthetic joint infections
Orthopaedic Proceedings, 2018Co-Authors: I. K. Sigmund, Katsiaryna Yermak, N Renz, Andrej TrampuzAbstract:Aim Alpha-Defensin is a new synovial fluid biomarker for the diagnosis of periprosthetic joint infections (PJI). We compared the performance of two different Alpha-Defensin assays: quantitative ELI...
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performance of the Alpha Defensin lateral flow test for diagnosis of hip and knee periprosthetic joint infection
Orthopaedic Proceedings, 2018Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Aim The aim of the study was to assess the accuracy of the Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection (PJI) using an optimized diagnostic algorithm and three c...
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PERFORMANCE OF THE Alpha-Defensin LATERAL FLOW TEST FOR DIAGNOSIS OF HIP AND KNEE PERIPROSTHETIC JOINT INFECTION
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Aim The aim of the study was to assess the accuracy of the Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection (PJI) using an optimized diagnostic algorithm and three classification systems. In addition, we compared the performance with synovial fluid leukocyte count, the most sensitive preoperative test. Method In this prospective multicenter study we included all consecutive patients with painful prosthetic hip and knee joints undergoing diagnostic joint aspiration. Alpha Defensin lateral flow test was used according to manufacturer instructions. The following diagnostic criteria were used to confirm infection: Musculoskeletal Infection Society (MSIS), Infectious Diseases Society of America (IDSA) and Swiss orthopedics and Swiss Society of Infectious Diseases (SOSSID). In the latter, PJI was confirmed when at least one of following criteria applied: macroscopic purulence, sinus tract, positive cytology of joint aspirate (>2000 leukocytes/μl or >70% granulocytes), histological proof of acute inflammation in periprosthetic tissue, positive culture (from aspirate, tissue or sonication fluid). Infection was classified as chronic, if symptom duration was more than 3 weeks or if infection manifested after more than 1 month after surgery. The sensitivity and specificity of the Alpha Defensin lateral flow test and leukocyte count in synovial fluid were calculated and compared using McNemar Chi-square test. Results Of 151 included patients evaluated for painful prosthetic joints (103 involved knees, 48 hips), the median patient age was 69 years (range, 41–94 years) and 75 patients were female. Systematically evaluating the included patients according to the different diagnostic criteria, MSIS and IDSA revealed both 33 patients with PJI (22%), whereas SOSSID disclosed 47 septic failures (31%), among them 36 chronic infections (77%). Sensitivity of the test was 79% when applying MSIS criteria, 70% with IDSA criteria and 57% with SOSSID criteria. Specificity ranged from 96% (IDSA) to 98% (MSIS) and 99% (SOSSID). Applying the most stringent definition criteria (SOSSID), leukocyte count showed significantly higher sensitivity than the Alpha Defensin lateral flow test (91% vs. 57%, p Conclusions Semi-quantitative Alpha Defensin test was rapid and highly specific for diagnosing PJI (> 95%). However, sensitivity was limited, especially when applying definition criteria including also low grade infections (SOSSID criteria). Therefore, the Alpha Defensin lateral flow test does not allow a reliable exclusion of PJI, especially not in chronic infections but may be used as confirmatory test.
Carl Deirmengian - One of the best experts on this subject based on the ideXlab platform.
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validation of the Alpha Defensin lateral flow test for periprosthetic joint infection
Journal of Bone and Joint Surgery American Volume, 2021Co-Authors: Carl Deirmengian, John Madigan, Sujith Kallur Mallikarjuna, Janet Conway, Carlos A Higuera, Robin PatelAbstract:Background The synovial fluid test for Alpha Defensin has been reported to have an excellent performance in diagnosing periprosthetic joint infection (PJI). The purpose of this study was to evaluate the performance of the lateral flow test for synovial fluid Alpha Defensin by using the methods of a formal diagnostic accuracy study and to compare its performance with that of the laboratory-based Alpha Defensin test for PJI. Methods We conducted a diagnostic accuracy study of the index lateral flow immunoassay for synovial fluid Alpha Defensin relative to the reference 2013 Musculoskeletal Infection Society (MSIS) multicriteria definition of PJI. The study included a prospective multicenter cohort of outpatients with a failed hip or knee arthroplasty and a supplemental control cohort of fresh synovial fluid specimens submitted by physicians for diagnostic PJI testing. Results Among 57 patients with PJI and 248 patients without PJI in the overall prospective patient cohort, the sensitivity and specificity of the Alpha Defensin lateral flow test were 89.5% (95% confidence interval [CI]: 78.5% to 96.0%) and 94.8% (95% CI: 91.2% to 97.2%), respectively. The sensitivity increased to 94.3% (95% CI: 84.3% to 98.8%) after exclusion of 17 patients with grossly bloody aspirates (>1 million red blood cells/µL). Among the supplemental control cohort of fresh synovial fluid samples, including 65 samples from patients with PJI and 397 from patients without PJI, the sensitivity and specificity of the Alpha Defensin lateral flow test were 98.5% (95% CI: 91.7% to 100.0%) and 98.2% (95% CI: 96.4% to 99.3%), respectively. A comparison of the sensitivity and specificity of the Alpha Defensin lateral flow test with those of the Alpha Defensin enzyme-linked immunosorbent assay (ELISA) in the combined cohort did not demonstrate a significant difference in sensitivity (94.3% [95% CI: 88.5% to 97.7%] compared with 93.0% [95% CI: 87.1% to 96.7%]) or specificity (96.9% [95% CI: 95.3% to 98.1%] compared with 97.8% [95% CI: 96.4% to 98.8%]) (both p > 0.05). Conclusions The results of this study demonstrate the solid diagnostic performance of the Alpha Defensin test and have resulted in the U.S. Food and Drug Administration (FDA) authorization of the lateral-flow test with an intended use as an aid in the clinical diagnosis of PJI. Level of evidence Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.
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the Alpha Defensin test for periprosthetic joint infections is not affected by prior antibiotic administration
Clinical Orthopaedics and Related Research, 2016Co-Authors: Alisina Shahi, Carl Deirmengian, Javad Parvizi, Carlos A Higuera, Craig J Della Valle, Gregory S Kazarian, Salvatore J Frangiamore, Joshua S Bingham, Christopher P BeauchampAbstract:Background Previous studies have demonstrated that the administration of antibiotics to patients before performing diagnostic testing for periprosthetic joint infection (PJI) can interfere with the accuracy of test results. Although a single-institution study has suggested that Alpha-Defensin maintains its concentration and sensitivity even after antibiotic treatment, this has not yet been demonstrated in a larger multiinstitutional study.
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the Alpha Defensin test for periprosthetic joint infection responds to a wide spectrum of organisms
Clinical Orthopaedics and Related Research, 2015Co-Authors: Carl Deirmengian, Keith Kardos, Patrick Kilmartin, Simmi Gulati, Patrick A Citrano, Robert E. BoothAbstract:Background The Alpha-Defensin test has been previously demonstrated to be highly accurate in the diagnosis of prosthetic joint infection (PJI), nearly matching the Musculoskeletal Infection Society definition for PJI. However, the relationship between Alpha-Defensin levels and differing infecting organism has not yet been investigated.
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the Alpha Defensin test for periprosthetic joint infection outperforms the leukocyte esterase test strip
Clinical Orthopaedics and Related Research, 2015Co-Authors: Carl Deirmengian, Keith Kardos, Patrick Kilmartin, Kevin Schiller, Alexander Cameron, Robert E. Booth, Javad ParviziAbstract:Background Synovial fluid biomarkers have demonstrated diagnostic accuracy surpassing the currently used diagnostic tests for periprosthetic joint infection (PJI).
Javad Parvizi - One of the best experts on this subject based on the ideXlab platform.
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positive Alpha Defensin at reimplantation of a two stage revision arthroplasty is not associated with infection at 1 year
Clinical Orthopaedics and Related Research, 2019Co-Authors: Linsen T Samuel, Javad Parvizi, Assem A Sultan, Matthew Kheir, Jesus M Villa, Preetesh D Patel, Carlos A HigueraAbstract:BACKGROUND Diagnosing periprosthetic joint infection (PJI) represents a challenge that relies on multiple clinical and laboratory criteria that may not be consistently present. The synovial Alpha-Defensin-1 (AD-1) test has been shown to correlate accurately with the Musculoskeletal Infection Society (MSIS) criteria for the diagnosis of PJI, however, its association with persistent PJI has not been elucidated in the setting of patients receiving antibiotic spacers during second-stage reimplantation. Applying a Delphi-based consensus to define successful eradication of PJI offers an opportunity to test the utility of AD-1 in this setting. QUESTIONS/PURPOSES (1) Can the AD-1 test determine whether infection has been controlled using the Delphi criteria for persistent PJI as a surrogate for infection eradication during two-stage revision for PJI treatment with a spacer? (2) How does the performance of the AD-1 test compare with the MSIS criteria? METHODS This was a multicenter analysis of retrospectively collected data on patients who underwent a two-stage revision arthroplasty between May 2014 and July 2016. We included patients who had a previously confirmed PJI and received a cement spacer, underwent the second stage, had MSIS criteria data and a synovial fluid AD-1 test, and had a minimum followup of 1 year. We were unable to determine for all study sites how many patients had the test but did not meet all the criteria and so could not be studied; however, we were able to identify 69 patients (43 knees, 26 hips) who met all criteria. During the period in question, indications for use of AD-1 varied by surgeon; however, during that time, in general if a surgeon ordered it as part of the initial workup, the test would have been repeated before the second-stage reimplantation procedure. To assess the validity of AD-1 against persistence of PJI criteria at 1 year, the following were calculated using the Delphi criteria for persistent PJI as the gold standard: sensitivity, specificity, positive and negative predictive values, accuracy, and area under the curve (AUC) with 95% confidence intervals (CIs). Concordance index (c-index) and its Wald 95% CI with receiver operating characteristic (ROC) curve were calculated in relation to Delphi criteria for persistent PJI using AD-1 and then MSIS criteria. The two c-indices of AD-1 and MSIS were compared using the DeLong nonparametric approach. RESULTS The AD-1 test showed poor sensitivity (7%; 95% CI, 0.2-34), and poor overall accuracy (73%; 95% CI, 60-83; AUC = 0.5; 95% CI, 0.3-0.6) in detecting infection eradication at 1 year. The c-index for AD-1 versus Delphi criteria for persistent PJI was 0.519 (95% CI, 0.44-0.60), and the c-index for MSIS criteria versus Delphi criteria for persistent PJI was 0.518 (95% CI, 0.49-0.54), suggesting the weak diagnostic abilities of these models. The contrast estimate between MSIS criteria and AD-1 were not different from one another at -0.001 (95% CI%, -0.09 to 0.09; p = 0.99). CONCLUSIONS We found that a positive synovial fluid AD-1 test correlated poorly with the presence of persistent infection 1 year after two-stage revision arthroplasty for PJI. For this reason, we recommend against the routine use of AD-1 in patients with cement spacers, until or unless future studies demonstrate that the test is more effective than we found it to be. LEVEL OF EVIDENCE Level IV, diagnostic study.
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current recommendations for the diagnosis of acute and chronic pji for hip and knee cell counts Alpha Defensin leukocyte esterase next generation sequencing
Current Reviews in Musculoskeletal Medicine, 2018Co-Authors: Karan Goswami, Javad Parvizi, Maxwell P CourtneyAbstract:Despite significant progress in recent years, the diagnosis of periprosthetic joint infection (PJI) remains a challenge and no gold standard test exists. A combination of serological, synovial, microbiological, histological, and radiological investigations is performed that are expensive, often invasive, and imperfect. Novel biomarkers and molecular methods have shown promise in recent years. The purpose of this review is to provide an update about the diagnostic recommendations for PJI and cover a selection of emerging diagnostic tools. Recent literature highlights a new evidence-based definition for diagnosing hip and knee PJI that shows excellent performance on formal external multi-institutional validation. There is also increasing evidence to support the measurement of selected biomarkers in serum and synovial fluid, such as Alpha-Defensin, D-dimer, and interleukin-6. Finally, the emerging utility of next-generation sequencing for pathogen identification is discussed. In summary, we describe current recommendations and emerging tests for the diagnosis of PJI. Residual limitations and directions for future research are also discussed.
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can next generation sequencing play a role in detecting pathogens in synovial fluid
Journal of Bone and Joint Surgery-british Volume, 2018Co-Authors: Majd Tarabichi, Karan Goswami, Noam Shohat, Javad ParviziAbstract:AimsThe diagnosis of periprosthetic joint infection can be difficult due to the high rate of culture-negative infections. The aim of this study was to assess the use of next-generation sequencing for detecting organisms in synovial fluid.Materials and MethodsIn this prospective, single-blinded study, 86 anonymized samples of synovial fluid were obtained from patients undergoing aspiration of the hip or knee as part of the investigation of a periprosthetic infection. A panel of synovial fluid tests, including levels of C-reactive protein, human neutrophil elastase, total neutrophil count, Alpha-Defensin, and culture were performed prior to next-generation sequencing.ResultsOf these 86 samples, 30 were Alpha-Defensin-positive and culture-positive (Group I), 24 were Alpha-Defensin-positive and culture-negative (Group II) and 32 were Alpha-Defensin-negative and culture-negative (Group III). Next-generation sequencing was concordant with 25 results for Group I. In four of these, it detected antibiotic resistan...
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the Alpha Defensin test for diagnosing periprosthetic joint infection in the setting of an adverse local tissue reaction secondary to a failed metal on metal bearing or corrosion at the head neck junction
Journal of Arthroplasty, 2018Co-Authors: Kamil T Okroj, Javad Parvizi, Joshua S Bingham, Christopher P Beauchamp, Tyler E Calkins, Erdan Kayupov, Michael M Kheir, Craig J Della ValleAbstract:Abstract Background In patients with adverse local tissue reaction (ALTR) secondary to a failed metal-on-metal (MoM) bearing or corrosion at the head-neck junction in a metal-on-polyethylene bearing, ruling in or out periprosthetic joint infection (PJI) can be challenging. Alpha-Defensin has emerged as an accurate test for PJI. The purpose of this multicenter, retrospective study was to evaluate the accuracy of the Alpha-Defensin synovial fluid test in detecting PJI in patients with ALTR. Methods We reviewed medical records of 26 patients from 3 centers with ALTR that had an Alpha-Defensin test performed. Patients were assessed for PJI using the Musculoskeletal Infection Society criteria. Thirteen of these subjects had MoM total hip arthroplasty, 9 had ALTR secondary to head-neck corrosion, and 4 had MoM hip resurfacing. Results Only 1 of the 26 patients met Musculoskeletal Infection Society criteria for infection. However, 9 hips were Alpha-Defensin positive, including 1 true positive and 8 that were falsely positive (31%). All 8 of the false positives were also Synovasure positive, although 5 of 8 had an accompanying warning stating the results may be falsely positive due to a low synovial C-reactive protein value. Conclusion Similar to synovial fluid white blood cell count, Alpha-Defensin testing is prone to false-positive results in the setting of ALTR. Therefore, we recommend an aggressive approach to ruling out PJI including routine aspiration of all hips with ALTR before revision surgery to integrate the synovial fluid blood cell count, differential, cultures and adjunctive tests like Alpha-Defensin to allow for accurate diagnosis preoperatively.
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diagnosis of periprosthetic joint infection following hip and knee arthroplasty
Orthopedic Clinics of North America, 2016Co-Authors: Javad Parvizi, Safa Cyrus Fassihi, Mohammad A EnayatollahiAbstract:Abstract The diagnosis of periprosthetic joint infection (PJI) following total hip arthroplasty and total knee arthroplasty has been one of the major challenges in orthopedic surgery. As there is no single absolute test for diagnosis of PJI, diagnostic criteria for PJI have been proposed that include using several diagnostic modalities. Focused history, physical examination, plain radiographs, and initial serologic tests should be followed by joint aspiration and synovial analysis. Newer diagnostic techniques, such as Alpha-Defensin and interleukin-6, hold great promise in the future diagnosis of equivocal infections.
Nora Renz - One of the best experts on this subject based on the ideXlab platform.
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is the enzyme linked immunosorbent assay more accurate than the lateral flow Alpha Defensin test for diagnosing periprosthetic joint infection
Clinical Orthopaedics and Related Research, 2018Co-Authors: Irene Katharina Sigmund, Katsiaryna Yermak, Andrej Trampuz, Carsten Perka, Nora RenzAbstract:BACKGROUND: Alpha Defensin was proposed as a new biomarker in synovial fluid for the diagnostic workup of failed joint prostheses. To our knowledge, no comparative study of the performance of the quantitative enzyme-linked immunosorbent assay (ELISA) and qualitative lateral flow Alpha Defensin test has been reported. QUESTIONS/PURPOSES: (1) Using the proposed European Bone and Joint Infection Society (EBJIS) criteria for defining periprosthetic joint infection (PJI), is there a difference in the diagnostic accuracy of quantitative ELISA and qualitative lateral flow Alpha Defensin tests? (2) Is there a difference in the performance of the two Alpha Defensin tests when using three definition classification systems (Musculoskeletal Infection Society [MSIS], Infectious Diseases Society of America [IDSA], and proposed EBJIS)? METHODS: In this retrospective study of samples collected earlier as part of a related longitudinal study, we included patients in whom aspiration of the prosthetic hip or knee was performed as routine investigation before every revision arthroplasty. Between October 2016 and April 2017, a total of 73 patients were eligible for inclusion. As a result of an insufficient fluid volume for analysis (< 5 mL), two patients were excluded. Among the 71 patients in the final analysis, 54 had a knee and 17 a hip arthroplasty. Using the proposed EBJIS criteria, PJI was diagnosed in 22 patients (31%) and aseptic failure in 49 (69%). The Alpha Defensin ELISA and lateral flow tests were performed in synovial fluid. Patients were classified as having PJI or aseptic failure using the MSIS, the IDSA, and the proposed EBJIS criteria. Sensitivity and specificity of ELISA and the lateral flow Alpha Defensin test were calculated. Based on receiver operating characteristic analysis, area under the curve values were compared. RESULTS: When measured against the proposed EBJIS criteria, the sensitivity of Alpha Defensin ELISA and the lateral flow test was low and not different from one another with the numbers available at 50% (95% confidence interval [CI], 31%-69%) and 46% (95% CI, 27%-65%; p = 0.857), respectively, whereas both methods showed high specificity (98% [95% CI, 88%-100%]; p = 1.000). For sensitivity, the highest values were seen when compared against the MSIS criteria (ELISA: 85% [95% CI, 56%-97%], lateral flow: 77% [95% CI]; p = 0.871), intermediate with IDSA criteria (ELISA: 73% [95% CI, 48%-89%], lateral flow: 67% [95% CI]; p = 0.867), and lowest with proposed EBJIS criteria (ELISA: 50% [95% CI, 31%-69%], lateral flow: 46% [95% CI]; p = 0.763). Specificity, however, was high regardless of the criteria used, where ELISA and lateral flow produced results that were not different (MSIS: 98% [95% CI, 90%-100%], IDSA: 98% [95% CI, 90%-100%], EBJIS: 98% [95% CI, 88%-100%]; p = 1.000). The area under the curve of Alpha Defensin ELISA and the lateral flow test was similar, regardless of the definition criteria used (EBJIS: p = 0.566; IDSA: p = 0.425; MSIS: p = 0.339). CONCLUSIONS: There is no difference between the quantitative and qualitative Alpha Defensin test for confirmation of PJI, irrespective of applied definition criteria. Having the advantage of providing results within 10 minutes without the need for a laboratory facility, the qualitative test may be of interest in the intraoperative setting, however, at a cost of higher test expense. LEVEL OF EVIDENCE: Level I, diagnostic study.
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Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection not a screening but a confirmatory test
Journal of Bone and Joint Surgery American Volume, 2018Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Background:Determination of Alpha Defensin in synovial fluid has shown promising results for diagnosing periprosthetic joint infection (PJI). The purposes of our study were to assess the performance of Alpha Defensin lateral flow (ADLF) test for the diagnosis of acute and chronic PJI using 3 classif
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performance of the Alpha Defensin lateral flow test for diagnosis of hip and knee periprosthetic joint infection
Orthopaedic Proceedings, 2018Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Aim The aim of the study was to assess the accuracy of the Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection (PJI) using an optimized diagnostic algorithm and three c...
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PERFORMANCE OF THE Alpha-Defensin LATERAL FLOW TEST FOR DIAGNOSIS OF HIP AND KNEE PERIPROSTHETIC JOINT INFECTION
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Aim The aim of the study was to assess the accuracy of the Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection (PJI) using an optimized diagnostic algorithm and three classification systems. In addition, we compared the performance with synovial fluid leukocyte count, the most sensitive preoperative test. Method In this prospective multicenter study we included all consecutive patients with painful prosthetic hip and knee joints undergoing diagnostic joint aspiration. Alpha Defensin lateral flow test was used according to manufacturer instructions. The following diagnostic criteria were used to confirm infection: Musculoskeletal Infection Society (MSIS), Infectious Diseases Society of America (IDSA) and Swiss orthopedics and Swiss Society of Infectious Diseases (SOSSID). In the latter, PJI was confirmed when at least one of following criteria applied: macroscopic purulence, sinus tract, positive cytology of joint aspirate (>2000 leukocytes/μl or >70% granulocytes), histological proof of acute inflammation in periprosthetic tissue, positive culture (from aspirate, tissue or sonication fluid). Infection was classified as chronic, if symptom duration was more than 3 weeks or if infection manifested after more than 1 month after surgery. The sensitivity and specificity of the Alpha Defensin lateral flow test and leukocyte count in synovial fluid were calculated and compared using McNemar Chi-square test. Results Of 151 included patients evaluated for painful prosthetic joints (103 involved knees, 48 hips), the median patient age was 69 years (range, 41–94 years) and 75 patients were female. Systematically evaluating the included patients according to the different diagnostic criteria, MSIS and IDSA revealed both 33 patients with PJI (22%), whereas SOSSID disclosed 47 septic failures (31%), among them 36 chronic infections (77%). Sensitivity of the test was 79% when applying MSIS criteria, 70% with IDSA criteria and 57% with SOSSID criteria. Specificity ranged from 96% (IDSA) to 98% (MSIS) and 99% (SOSSID). Applying the most stringent definition criteria (SOSSID), leukocyte count showed significantly higher sensitivity than the Alpha Defensin lateral flow test (91% vs. 57%, p Conclusions Semi-quantitative Alpha Defensin test was rapid and highly specific for diagnosing PJI (> 95%). However, sensitivity was limited, especially when applying definition criteria including also low grade infections (SOSSID criteria). Therefore, the Alpha Defensin lateral flow test does not allow a reliable exclusion of PJI, especially not in chronic infections but may be used as confirmatory test.
Katsiaryna Yermak - One of the best experts on this subject based on the ideXlab platform.
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is the enzyme linked immunosorbent assay more accurate than the lateral flow Alpha Defensin test for diagnosing periprosthetic joint infection
Clinical Orthopaedics and Related Research, 2018Co-Authors: Irene Katharina Sigmund, Katsiaryna Yermak, Andrej Trampuz, Carsten Perka, Nora RenzAbstract:BACKGROUND: Alpha Defensin was proposed as a new biomarker in synovial fluid for the diagnostic workup of failed joint prostheses. To our knowledge, no comparative study of the performance of the quantitative enzyme-linked immunosorbent assay (ELISA) and qualitative lateral flow Alpha Defensin test has been reported. QUESTIONS/PURPOSES: (1) Using the proposed European Bone and Joint Infection Society (EBJIS) criteria for defining periprosthetic joint infection (PJI), is there a difference in the diagnostic accuracy of quantitative ELISA and qualitative lateral flow Alpha Defensin tests? (2) Is there a difference in the performance of the two Alpha Defensin tests when using three definition classification systems (Musculoskeletal Infection Society [MSIS], Infectious Diseases Society of America [IDSA], and proposed EBJIS)? METHODS: In this retrospective study of samples collected earlier as part of a related longitudinal study, we included patients in whom aspiration of the prosthetic hip or knee was performed as routine investigation before every revision arthroplasty. Between October 2016 and April 2017, a total of 73 patients were eligible for inclusion. As a result of an insufficient fluid volume for analysis (< 5 mL), two patients were excluded. Among the 71 patients in the final analysis, 54 had a knee and 17 a hip arthroplasty. Using the proposed EBJIS criteria, PJI was diagnosed in 22 patients (31%) and aseptic failure in 49 (69%). The Alpha Defensin ELISA and lateral flow tests were performed in synovial fluid. Patients were classified as having PJI or aseptic failure using the MSIS, the IDSA, and the proposed EBJIS criteria. Sensitivity and specificity of ELISA and the lateral flow Alpha Defensin test were calculated. Based on receiver operating characteristic analysis, area under the curve values were compared. RESULTS: When measured against the proposed EBJIS criteria, the sensitivity of Alpha Defensin ELISA and the lateral flow test was low and not different from one another with the numbers available at 50% (95% confidence interval [CI], 31%-69%) and 46% (95% CI, 27%-65%; p = 0.857), respectively, whereas both methods showed high specificity (98% [95% CI, 88%-100%]; p = 1.000). For sensitivity, the highest values were seen when compared against the MSIS criteria (ELISA: 85% [95% CI, 56%-97%], lateral flow: 77% [95% CI]; p = 0.871), intermediate with IDSA criteria (ELISA: 73% [95% CI, 48%-89%], lateral flow: 67% [95% CI]; p = 0.867), and lowest with proposed EBJIS criteria (ELISA: 50% [95% CI, 31%-69%], lateral flow: 46% [95% CI]; p = 0.763). Specificity, however, was high regardless of the criteria used, where ELISA and lateral flow produced results that were not different (MSIS: 98% [95% CI, 90%-100%], IDSA: 98% [95% CI, 90%-100%], EBJIS: 98% [95% CI, 88%-100%]; p = 1.000). The area under the curve of Alpha Defensin ELISA and the lateral flow test was similar, regardless of the definition criteria used (EBJIS: p = 0.566; IDSA: p = 0.425; MSIS: p = 0.339). CONCLUSIONS: There is no difference between the quantitative and qualitative Alpha Defensin test for confirmation of PJI, irrespective of applied definition criteria. Having the advantage of providing results within 10 minutes without the need for a laboratory facility, the qualitative test may be of interest in the intraoperative setting, however, at a cost of higher test expense. LEVEL OF EVIDENCE: Level I, diagnostic study.
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Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection not a screening but a confirmatory test
Journal of Bone and Joint Surgery American Volume, 2018Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Background:Determination of Alpha Defensin in synovial fluid has shown promising results for diagnosing periprosthetic joint infection (PJI). The purposes of our study were to assess the performance of Alpha Defensin lateral flow (ADLF) test for the diagnosis of acute and chronic PJI using 3 classif
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comparison of quantitative and qualitative Alpha Defensin test for diagnosing periprosthetic joint infections
Orthopaedic Proceedings, 2018Co-Authors: I. K. Sigmund, Katsiaryna Yermak, N Renz, Andrej TrampuzAbstract:Aim Alpha-Defensin is a new synovial fluid biomarker for the diagnosis of periprosthetic joint infections (PJI). We compared the performance of two different Alpha-Defensin assays: quantitative ELI...
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performance of the Alpha Defensin lateral flow test for diagnosis of hip and knee periprosthetic joint infection
Orthopaedic Proceedings, 2018Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Aim The aim of the study was to assess the accuracy of the Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection (PJI) using an optimized diagnostic algorithm and three c...
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PERFORMANCE OF THE Alpha-Defensin LATERAL FLOW TEST FOR DIAGNOSIS OF HIP AND KNEE PERIPROSTHETIC JOINT INFECTION
Journal of Bone and Joint Surgery-british Volume, 2017Co-Authors: Nora Renz, Katsiaryna Yermak, Carsten Perka, Andrej TrampuzAbstract:Aim The aim of the study was to assess the accuracy of the Alpha Defensin lateral flow test for diagnosis of periprosthetic joint infection (PJI) using an optimized diagnostic algorithm and three classification systems. In addition, we compared the performance with synovial fluid leukocyte count, the most sensitive preoperative test. Method In this prospective multicenter study we included all consecutive patients with painful prosthetic hip and knee joints undergoing diagnostic joint aspiration. Alpha Defensin lateral flow test was used according to manufacturer instructions. The following diagnostic criteria were used to confirm infection: Musculoskeletal Infection Society (MSIS), Infectious Diseases Society of America (IDSA) and Swiss orthopedics and Swiss Society of Infectious Diseases (SOSSID). In the latter, PJI was confirmed when at least one of following criteria applied: macroscopic purulence, sinus tract, positive cytology of joint aspirate (>2000 leukocytes/μl or >70% granulocytes), histological proof of acute inflammation in periprosthetic tissue, positive culture (from aspirate, tissue or sonication fluid). Infection was classified as chronic, if symptom duration was more than 3 weeks or if infection manifested after more than 1 month after surgery. The sensitivity and specificity of the Alpha Defensin lateral flow test and leukocyte count in synovial fluid were calculated and compared using McNemar Chi-square test. Results Of 151 included patients evaluated for painful prosthetic joints (103 involved knees, 48 hips), the median patient age was 69 years (range, 41–94 years) and 75 patients were female. Systematically evaluating the included patients according to the different diagnostic criteria, MSIS and IDSA revealed both 33 patients with PJI (22%), whereas SOSSID disclosed 47 septic failures (31%), among them 36 chronic infections (77%). Sensitivity of the test was 79% when applying MSIS criteria, 70% with IDSA criteria and 57% with SOSSID criteria. Specificity ranged from 96% (IDSA) to 98% (MSIS) and 99% (SOSSID). Applying the most stringent definition criteria (SOSSID), leukocyte count showed significantly higher sensitivity than the Alpha Defensin lateral flow test (91% vs. 57%, p Conclusions Semi-quantitative Alpha Defensin test was rapid and highly specific for diagnosing PJI (> 95%). However, sensitivity was limited, especially when applying definition criteria including also low grade infections (SOSSID criteria). Therefore, the Alpha Defensin lateral flow test does not allow a reliable exclusion of PJI, especially not in chronic infections but may be used as confirmatory test.