An optimized stepwise algorithm combining rapid antigen and RT-qPCR for screening of COVID-19 patients

Background & aim We investigated the combination of rapid antigen detection (RAD) and RT-qPCR assays in a stepwise procedure to optimize the detection of COVID-19. Methods From August 2020 to November 2020, 43,399 patients were screened in our laboratory for COVID-19 diagnostic by RT-qPCR using nasopharyngeal swab. Overall, 4,691 of the 43,399 were found to be positive, and 200 were retrieved for RAD testing allowing comparison of diagnostic accuracy between RAD and RT-qPCR. Cycle threshold (Ct) and time from symptoms onset (TSO) were included as covariates. Results The overall sensitivity, specificity, PPV, NPV, LR-, and LR+ of RAD compared with RT-qPCR were 72% (95%CI 62%–81%), 99% (95% CI95%–100%), 99% (95%CI 93%–100%), and 78% (95%CI 70%–85%), 0.28 (95%CI 0.21–0.39), and 72 (95%CI 10–208) respectively. Sensitivity was higher for patients with Ct ≤ 25 regardless of TSO: TSO ≤ 4 days 92% (95%CI 75%–99%), TSO > 4 days 100% (95%CI 54%–100%), and asymptomatic 100% (95%CI 78–100%). Overall, combining RAD and RT-qPCR would allow reducing from only 4% the number of RT-qPCR needed. Conclusions This study highlights the risk of misdiagnosing COVID-19 in 28% of patients if RAD is used alone. A stepwise analysis that combines RAD and RT-qPCR would be an efficient screening procedure for COVID-19 detection and may facilitate the control of the outbreak.

Download Full-text

An optimized stepwise algorithm combining rapid antigen and RT-qPCR for screening of COVID-19 patients

10.1101/2021.01.13.21249254 ◽

2021 ◽

Author(s):

Philippe Halfon ◽

Guillaume Penaranda ◽

Hacène Khiri ◽

Vincent Garcia ◽

Hortense Drouet ◽

...

Keyword(s):

Case Management ◽

Diagnostic Accuracy ◽

Treatment Decisions ◽

Screening Procedure ◽

Nasopharyngeal Swab ◽

Cycle Threshold ◽

Negative Results ◽

Stepwise Procedure ◽

Sensitivity Specificity ◽

Efficient Screening

AbstractBackgroundDiagnosing SARS CoV-2 infection with certainty is essential for appropriate case management. We investigated the combination of rapid antigen detection (RAD) and RT-qPCR assays in a stepwise procedure to optimize the detection of COVID-19.MethodsFrom August 2020 to November 2020, 43,399 patients were screened in our laboratory for COVID-19 diagnostic by RT-qPCR using nasopharyngeal swab. Overall, 4,691 of the 43,399 were found to be positive, and 200 were retrieved for RAD testing allowing comparison of diagnostic accuracy between RAD and RT-qPCR. Cycle threshold (Ct) and time from symptoms onset (TSO) were included as covariates.ResultsThe overall sensitivity, specificity, PPV, NPV, LR-, and LR+ of RAD compared with RT- qPCR were 72% (95%CI 62%–81%), 99% (95% CI95%–100%), 99% (95%CI 93%–100%), and 78% (95%CI 70%–85%), 0.28 (95%CI 0.21-0.39), and 72 (95%CI 10-208) respectively. Sensitivity was higher for patients with Ct ≤ 25 regardless of TSO: TSO ≤ 4 days 92% (95%CI 75%–99%), TSO > 4 days 100% (95%CI 54%–100%), and asymptomatic 100% (95%CI 78-100%). Overall, combining RAD and RT-qPCR would allow reducing from only 4% the number of RT-qPCR needed.ConclusionThis study highlights the risk of misdiagnosing COVID-19 in 28% of patients if RAD is used alone. Thus, negative results from RAD needs to be confirmed by RT-qPCR prior to making treatment decisions. A stepwise analysis that combines RAD and RT-qPCR would be an efficient screening procedure for COVID-19 detection and may facilitate the control of the outbreak.

Download Full-text

DIAGNOSTIC ACCURACY OF PANBIO COVID-19 RAPID ANTIGEN METHOD FOR SCREENING IN EMERGENCY CASES

Pakistan Armed Forces Medical Journal ◽

10.51253/pafmj.v71i5.6708 ◽

2021 ◽

Vol 71 (5) ◽

pp. 1607-10

Author(s):

Raja Kamran Afzal ◽

Saad Ali ◽

Farooq Ahmad ◽

Shafia Nasir ◽

Muhammad Younas ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Diagnostic Accuracy ◽

Predictive Value ◽

Military Hospital ◽

Ethical Review ◽

Nasopharyngeal Swab ◽

Chain Reaction ◽

Cross Sectional ◽

Polymerase Chain ◽

Sensitivity Specificity

Objective: To determine the diagnostic accuracy of PANBIO COVID-19 rapid antigen method in nasopharyngeal swab, for screening of COVID-19 infection in emergency cases. Study Design: Cross-sectional validation study. Place and Duration of Study: Department of Microbiology, Combined Military Hospital, Multan, from Jan to Mar 2021. Methodology: After taking approval from institutional ethical review committee, total 1539 patients were included in this study according to sample size. With informed consent, nasopharyngeal swab specimens were taken for PANBIO COVID-19 rapid antigen method from each patient presenting as emergency medical/surgical case to Combined Military Hospital Multan as well as for Polymerase Chain Reaction for SARS CoV-2 RNA. PANBIO COVID-19 rapid antigen method and polymerase chain reaction for SARS CoV-2 RNA were performed simultaneously on swabs. Polymerase chain reaction for SARS CoV-2 RNA was considered to be the gold standard for comparison with the PANBIO COVID-19 rapid antigen method. Results: A total of 21 patients had SARS CoV-2 RNA detected by polymerase chain reaction indicating COVID-19 infection. Out of polymerase chain reaction positive patients, PANBIO™ COVID-19 Ag test was able to detect 19 cases. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy was calculated and found to be 90.47%, 100%, 100%, 99.8% and 99.8% respectively. Conclusion: PANBIO™ COVID-19 rapid antigen method was found to have excellent diagnostic accuracy in detection of COVID-19 infection. It can provide as a good alternate test for screening of masses with a short turn around time of only 15 minutes.

Download Full-text

Anterior nasal versus nasal mid-turbinate sampling for a SARS-CoV-2 antigen-detecting rapid test: does localisation or professional collection matter?

10.1101/2021.02.09.21251274 ◽

2021 ◽

Cited By ~ 2

Author(s):

Olga Nikolai ◽

Chiara Rohardt ◽

Frank Tobian ◽

Andrea Junge ◽

Victor M. Corman ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Rapid Test ◽

Nasopharyngeal Swab ◽

Diagnostic Accuracy Study ◽

Rt Pcr ◽

Percent Agreement ◽

Accuracy Study ◽

Polymerase Chain ◽

Sensitivity Specificity ◽

Antigen Testing

AbstractObjectivesThe aim of this diagnostic accuracy study was direct comparison of two different nasal sampling methods for an antigen-based rapid diagnostic test (Ag-RDT) that detects severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Furthermore, the accuracy and feasibility of self-sampling was evaluated.MethodsThis manufacturer-independent, prospective diagnostic accuracy study, compared professional anterior nasal (AN) and nasal mid-turbinate (NMT) sampling for a WHO-listed SARS-CoV-2 Ag-RDT. A second group of participants collected a NMT sample themselves and underwent a professional nasopharyngeal swab for comparison. The reference standard was real-time polymerase chain reaction (RT-PCR) using combined oro-/nasopharyngeal sampling. Individuals with high suspicion of SARS-CoV-2 infection were tested. Sensitivity, specificity, and percent agreement were calculated. Self-sampling was observed without intervention. Feasibility was evaluated by observer and participant questionnaires.ResultsAmong 132 symptomatic adults, both professional AN- and NMT-sampling yielded a sensitivity of 86.1% (31/36 RT-PCR positives detected; 95%CI: 71.3-93.9) and a specificity of 100.0% (95%CI: 95.7-100). The positive percent agreement (PPA) was 100% (95%CI: 89.0-100). Among 96 additional adults, self NMT- and professional NP-sampling yielded an identical sensitivity of 91.2% (31/34; 95%CI 77.0-97.0). Specificity was 98.4% (95%CI: 91.4-99.9) with NMT- and 100.0% (95%CI: 94.2-100) with NP-sampling. The PPA was 96.8% (95%CI: 83.8-99.8). Most participants (85.3%) considered self-sampling as easy to perform.ConclusionProfessional AN- and NMT-sampling are of equivalent accuracy for an Ag-RDT in ambulatory symptomatic adults. Participants were able to reliably perform the NMT-sampling themselves, following written and illustrated instructions. Nasal self-sampling will likely facilitate scaling of SARS-CoV-2 antigen testing.

Download Full-text

Clausal Density Between Ages 4 and 9 Years for the Edmonton Narrative Norms Instrument: Reference Data and Psychometric Properties

Language Speech and Hearing Services in Schools ◽

10.1044/2020_lshss-20-00043 ◽

2020 ◽

pp. 1-15

Author(s):

Ling-Yu Guo ◽

Phyllis Schneider ◽

William Harrison

Keyword(s):

Diagnostic Accuracy ◽

Psychometric Properties ◽

Language Impairment ◽

Reference Data ◽

Reliability And Validity ◽

Correlation Coefficients ◽

Criterion Validity ◽

Likelihood Ratios ◽

Generation Task ◽

Sensitivity Specificity

Purpose This study provided reference data and examined psychometric properties for clausal density (CD; i.e., number of clauses per utterance) in children between ages 4 and 9 years from the database of the Edmonton Narrative Norms Instrument (ENNI). Method Participants in the ENNI database included 300 children with typical language (TL) and 77 children with language impairment (LI) between the ages of 4;0 (years;months) and 9;11. Narrative samples were collected using a story generation task, in which children were asked to tell stories based on six picture sequences. CD was computed from the narrative samples. The split-half reliability, concurrent criterion validity, and diagnostic accuracy were evaluated for CD by age. Results CD scores increased significantly between ages 4 and 9 years in children with TL and those with LI. Children with TL produced higher CD scores than those with LI at each age level. In addition, the correlation coefficients for the split-half reliability and concurrent criterion validity of CD scores were all significant at each age level, with the magnitude ranging from small to large. The diagnostic accuracy of CD scores, as revealed by sensitivity, specificity, and likelihood ratios, was poor. Conclusions The finding on diagnostic accuracy did not support the use of CD for identifying children with LI between ages 4 and 9 years. However, given the attested reliability and validity for CD, reference data of CD from the ENNI database can be used for evaluating children's difficulties with complex syntax and monitoring their change over time. Supplemental Material https://doi.org/10.23641/asha.13172129

Download Full-text

Noninvasive Evaluation of Coronary Artery Bypass Grafts with 16-Slice Multidetector Computed Tomography

The Heart Surgery Forum ◽

10.1532/hsf98.20111075 ◽

2012 ◽

Vol 15 (1) ◽

pp. 12 ◽

Cited By ~ 1

Author(s):

Levent Sahiner ◽

Ali Oto ◽

Kudret Aytemir ◽

Tuncay Hazirolan ◽

Musturay Karcaaltincaba ◽

...

Keyword(s):

Computed Tomography ◽

Coronary Artery ◽

Diagnostic Accuracy ◽

Multidetector Computed Tomography ◽

Coronary Artery Bypass ◽

Predictive Value ◽

Artery Bypass ◽

Time Interval ◽

Mdct Angiography ◽

Sensitivity Specificity

Background: The aim of this study was to investigate the diagnostic accuracy of 16-slice multislice, multidetector computed tomography (MDCT) angiography for the evaluation of grafts in patients with coronary artery bypass grafting (CABG).Methods: Fifty-eight consecutive patients with CABG who underwent both MDCT and conventional invasive coronary angiography were included. The median time interval between the 2 procedures was 10 days (range, 1-32 days). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDCT for the detection of occluded grafts were calculated. The accuracy of MDCT angiography for detecting significant stenoses in patent grafts and the evaluability of proximal and distal anastomoses were also investigated.Results: Optimal diagnostic images could not be obtained for only 3 (2%) of 153 grafts. Evaluation of the remaining 150 grafts revealed values for sensitivity, specificity, PPV, NPV, and diagnostic accuracy of the MDCT angiography procedure for the diagnosis of occluded grafts of 87%, 97%, 94%, 93%, and 92%, respectively. All of the proximal anastomoses were optimally visualized. In 4 (8%) of 50 patent arterial grafts, however, the distal anastomotic region could not be evaluated because of motion and surgical-clip artifacts. The accuracy of MDCT angiography for the detection of significant stenotic lesions was relatively low (the sensitivity, specificity, PPV, and NPV were 67%, 98%, 50%, and 99%, respectively). The number of significant lesions was insufficient to reach a reliable conclusion, however.Conclusion: Our study showed that MDCT angiography with 16-slice systems has acceptable diagnostic performance for the evaluation of coronary artery bypass graft patency.

Download Full-text

The role of serum periostin in the diagnosis of asthma: A meta-analysis

Allergy and Asthma Proceedings ◽

10.2500/aap.2020.41.200038 ◽

2020 ◽

Vol 41 (4) ◽

pp. 240-247

Author(s):

Lei Yang ◽

Qingtao Zhao ◽

Shuyu Wang

Keyword(s):

Diagnostic Accuracy ◽

Meta Analysis ◽

Characteristic Curve ◽

False Negative ◽

Summary Receiver Operating Characteristic ◽

True Negative ◽

Negative Results ◽

Noninvasive Biomarker ◽

Sensitivity Specificity ◽

Serum Periostin

Background: Serum periostin has been proposed as a noninvasive biomarker for asthma diagnosis and management. However, its accuracy for the diagnosis of asthma in different populations is not completely clear. Methods: This meta-analysis aimed to evaluate the diagnostic accuracy of periostin level in the clinical determination of asthma. Several medical literature data bases were searched for relevant studies through December 1, 2019. The numbers of patients with true-positive, false-positive, false-negative, and true-negative results for the periostin level were extracted from each individual study. We assessed the risk of bias by using Quality Assessment of Diagnostic Accuracy Studies 2. We used the meta-analysis to produce summary estimates of accuracy. Results: In total, nine studies with 1757 subjects met the inclusion criteria. The pooled estimates of sensitivity, specificity, and diagnostic odds ratios for the detection of asthma were 0.58 (95% confidence interval [CI], 0.38‐0.76), 0.86 (95% CI, 0.74‐0.93), and 8.28 (95% CI, 3.67‐18.68), respectively. The area under the summary receiver operating characteristic curve was 0.82 (95% CI, 0.79‐0.85). And significant publication bias was found in this meta‐analysis (p = 0.39). Conclusion: Serum periostin may be used for the diagnosis of asthma, with moderate diagnostic accuracy.

Download Full-text

Pre-Procedural COVID-19 Nasopharyngeal Swab Has Good Concordance with Bronchoalveolar Lavage in Patients at Low Risk for Viral Infection

Respiration ◽

10.1159/000514928 ◽

2021 ◽

pp. 1-5

Author(s):

Catherine L. Oberg ◽

Reza Ronaghi ◽

Erik E. Folch ◽

Colleen L. Channick ◽

Tao He ◽

...

Keyword(s):

Bronchoalveolar Lavage ◽

Low Risk ◽

Lower Airway ◽

Nasopharyngeal Swab ◽

Symptom Screening ◽

The World ◽

Good Concordance ◽

Sensitivity Specificity ◽

Overall Reliability ◽

Rule Out

Background: The coronavirus disease 2019 (COVID-19) pandemic has drastically affected hospital and operating room (OR) workflow around the world as well as trainee education. Many institutions have instituted mandatory preoperative SARS-CoV-2 PCR nasopharyngeal swab (NS) testing in patients who are low risk for COVID-19 prior to elective cases. This method, however, is challenging as the sensitivity, specificity, and overall reliability of testing remains unclear. Objectives: The objective of this study was to assess the concordance of a negative NS in low risk preoperative patients with lower airway bronchoalveolar lavage (BAL) specimens obtained from the same patients. Methods: We prospectively sent intraoperative lower airway BAL samples collected within 48 h of a negative mandatory preoperative NS for SARS-CoV-2 PCR testing. All adult patients undergoing a scheduled bronchoscopic procedure for any reason were enrolled, including elective and nonelective cases. Results: One-hundred eighty-nine patients were included. All BAL specimens were negative for SARS-CoV-2 indicative of 100% concordance between testing modalities. Conclusions: These results are promising and suggest that preoperative nasopharyngeal SARS-CoV-2 testing provides adequate screening to rule out active COVID-19 infection prior to OR cases in a population characterized as low risk by negative symptom screening. This information can be used for both pre-procedural screening and when reintroducing trainees into the workforce.

Download Full-text

The Potential Diagnostic Accuracy of Circulating MicroRNAs for Leukemia: A Meta-Analysis

Technology in Cancer Research & Treatment ◽

10.1177/15330338211011958 ◽

2021 ◽

Vol 20 ◽

pp. 153303382110119

Author(s):

Wen-Ting Zhang ◽

Guo-Xun Zhang ◽

Shuai-Shuai Gao

Keyword(s):

Diagnostic Accuracy ◽

Likelihood Ratio ◽

Subgroup Analysis ◽

Meta Analysis ◽

Area Under The Curve ◽

Positive Likelihood Ratio ◽

Negative Likelihood Ratio ◽

Diagnostic Odds Ratio ◽

Circulating Micrornas ◽

Sensitivity Specificity

Background: Leukemia is a common malignant disease in the human blood system. Many researchers have proposed circulating microRNAs as biomarkers for the diagnosis of leukemia. We conducted a meta-analysis to evaluate the diagnostic accuracy of circulating miRNAs in the diagnosis of leukemia. Methods: A comprehensive literature search (updated to October 13, 2020) in PubMed, EMBASE, Web of Science, Cochrane Library, Wanfang database and China National Knowledge Infrastructure (CNKI) was performed to identify eligible studies. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) for diagnosing leukemia were pooled for both overall and subgroup analysis. The meta-regression and subgroup analysis were performed to explore heterogeneity and Deeks’ funnel plot was used to assess publication bias. Results: 49 studies from 22 publications with a total of 3,489 leukemia patients and 2,756 healthy controls were included in this meta-analysis. The overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the curve were 0.83, 0.92, 10.8, 0.18, 59 and 0.94, respectively. Subgroup analysis shows that the microRNA clusters of plasma type could carry out a better diagnostic accuracy of leukemia patients. In addition, publication bias was not found. Conclusions: Circulating microRNAs can be used as a promising noninvasive biomarker in the early diagnosis of leukemia.

Download Full-text

Comparison of saliva with healthcare workers- and patient-collected swabs in the diagnosis of COVID-19 in a large cohort

BMC Infectious Diseases ◽

10.1186/s12879-021-06343-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Mitnala Sasikala ◽

Yelamanchili Sadhana ◽

Ketavarapu Vijayasarathy ◽

Anand Gupta ◽

Sarala Kumari Daram ◽

...

Keyword(s):

Healthcare Workers ◽

Early Stage ◽

Cost Effective ◽

Hospitalized Patients ◽

Detection Sensitivity ◽

Nasopharyngeal Swab ◽

Predictive Values ◽

Qrt Pcr ◽

Asymptomatic Patients ◽

Sensitivity Specificity

Abstract Background A considerable amount of evidence demonstrates the potential of saliva in the diagnosis of COVID-19. Our aim was to determine the sensitivity of saliva versus swabs collected by healthcare workers (HCWs) and patients themselves to assess whether saliva detection can be offered as a cost-effective, risk-free method of SARS-CoV-2 detection. Methods This study was conducted in a hospital involving outpatients and hospitalized patients. A total of 3018 outpatients were tested. Of these, 200 qRT-PCR-confirmed SARS-CoV-2-positive patients were recruited for further study. In addition, 101 SARS-CoV-2-positive hospitalized patients with symptoms were also enrolled in the study. From outpatients, HCWs collected nasopharyngeal swabs (NPS), saliva were obtained. From inpatients, HCWs collected swabs, patient-collected swabs, and saliva were obtained. qRT-PCR was performed to detect SARS-CoV-2 by TAQPATH assay to determine the sensitivity of saliva detection. Sensitivity, specificity and positive/negative predictive values (PPV, NPV) of detecting SARS-CoV-2 were calculated using MedCalc. Results Of 3018 outpatients (asymptomatic: 2683, symptomatic: 335) tested by qRT-PCR, 200 were positive (males: 140, females: 60; aged 37.9 ± 12.8 years; (81 asymptomatic, 119 symptomatic). Of these, saliva was positive in 128 (64%); 39 of 81 asymptomatic (47%),89 of 119 symptomatic patients (74.8%). Sensitivity of detection was 60.9% (55.4–66.3%, CI 95%), with a negative predictive value of 36%(32.9–39.2%, CI 95%).Among 101 hospitalized patients (males:65, females: 36; aged 53.48 ± 15.6 years), with HCW collected NPS as comparator, sensitivity of saliva was 56.1% (47.5–64.5, CI 95%), specificity 63.5%(50.4–75.3, CI95%) with PPV of 77.2% and NPV of 39.6% and that of self-swab was 52.3%(44–60.5%, CI95%), specificity 56.6% (42.3–70.2%, CI95%) with PPV 77.2% and NPV29.7%. Comparison of positivity with the onset of symptoms revealed highest detection in saliva on day 3 after onset of symptoms. Additionally, only saliva was positive in 13 (12.8%) hospitalized patients. Conclusion Saliva which is easier to collect than nasopharyngeal swab is a viable alternate to detect SARS-COV-2 in symptomatic patients in the early stage of onset of symptoms. Although saliva is currently not recommended for screening asymptomatic patients, optimization of collection and uniform timing of sampling might improve the sensitivity enabling its use as a screening tool at community level.

Download Full-text

AB0629 ACCURACY OF SYNOVIAL FLUID ANALYSIS FOR THE IDENTIFICATION OF CALCIUM PYROPHOSPHATE CRYSTALS: AN ANCILLARY STUDY OF OMERACT CRITERION VALIDITY STUDY FOR ULTRASOUND IN CPPD

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.601 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 1348.1-1348

Author(s):

A. Adinolfi ◽

S. Sirotti ◽

M. Gutierrez ◽

C. Pineda ◽

D. Clavijo Cornejo ◽

...

Keyword(s):

Synovial Fluid ◽

Diagnostic Accuracy ◽

Light Microscopy ◽

Hyaline Cartilage ◽

Microscopic Analysis ◽

Calcium Pyrophosphate ◽

Ancillary Study ◽

Fluid Analysis ◽

Synovial Fluid Analysis ◽

Sensitivity Specificity

Background:Synovial fluid analysis (SFA) via compensated polarized light microscopy is still considered the gold standard for the identification and diagnosis of Calcium Pyrophosphate Deposition disease (CPPD)-related arthropathies[1], but very few studies have been published about its diagnostic accuracy.Objectives:The aim of this study was to evaluate the accuracy of SFA in the identification of calcium pyrophosphate dihydrate (CPP) crystals compared to microscopic analysis of joint tissues as the reference standard.Methods:This is an ancillary study of an international, multicentre cross-sectional study performed by the CPPD subgroup of the OMERACT Ultrasound working group[2]. Consecutive patients with knee osteoarthritis (OA) waiting for total knee replacement surgery were enrolled in the study from 2 participating centres, Mexico and Romania. During surgical procedures synovial fluid (SF), menisci and hyaline cartilage were collected and analysed within 48 hours after surgery under transmitted light microscopy and compensated polarised light microscopy for the presence/absence of CPP crystals. All slides were analysed by expert examiners on site, blinded to other findings. A dichotomic score (absence/presence) was used for scoring both SF and tissues. Microscopic analysis of knee tissues was considered the gold standard. Sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV) of SFA in the identification of CPP crystals were calculated.Results:15 patients (53% female, mean age 68yo ± 8.4) with OA of grade 3 or 4 according to Kellgren-Lawrence scoring were enrolled. 12 patients (80%) were positive for CPP crystals at SFA and 14 (93%) at tissues microscopic analysis. Among 12 SFA positive patients, all were positive for CPP crystals in either medial or lateral meniscus, and 11 were positive in both; 10 patients were positive at the hyaline cartilage, and all 10 were also positive for at least one meniscus. Regarding the 3 SFA negative patients, only one had no crystals in the examined tissues, while the other 2 patients had CPP crystals in both menisci and hyaline cartilage. The overall diagnostic accuracy of SFA compared to histology analysis for CPPD was 87%, with a sensitivity of 86% and a specificity of 100%, the PPV was 100% and the NPV was 33% (Table 1).Table 1.sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of synovial fluid analysis compared to the reference standard. CI: Confidential Interval. SF: synovial fluid, in parentheses: numerators and denominators for all percentages provided.SensitivitySpecificityPPVNPVAccuracySF analysis86% (12/14)100% (1/1)100% (12/12)33% (1/3)87% (13/15)(0.65-0.99) CI 95%(0.0-0.25) CI 95%(0.65-0.99) CI 95%(0.0-0.25) CI 95%Conclusion:SFA demonstrated to be an accurate test for the identification of CPP crystals in patients with advanced OA. However, is not always feasible and carries some risks for the patient. Considering the availability of validated imaging techniques for the detection of CPPD, such as US, SFA could be used in those patients where imaging and clinical data are not definitely confirmatory of the disease.References:[1]W. Zhang et al., ‘European League Against Rheumatism recommendations for calcium pyrophosphate deposition. Part I: terminology and diagnosis’, Ann Rheum Dis, vol. 70, no. 4, pp. 563–570, Apr. 2011, doi: 10.1136/ard.2010.139105.[2]G. Filippou et al., ‘Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study’, Ann Rheum Dis, p. annrheumdis-2020-217998, Sep. 2020, doi: 10.1136/annrheumdis-2020-217998.Disclosure of Interests:None declared.

Download Full-text