THU0414 ORDINARY LIGHT MICROSCOPY IS ABLE TO IDENTIFY MOST CRYSTAL-CONTAINING SYNOVIAL FLUIDS

Background:Optical microscopy remains the gold standard for the diagnosis of crystal arthropathies. The complete protocol consists of three phases. In the first stage, microscopy with simple light provides information on the morphology of the crystal. The second stage, polarized light, allows detecting the intensity of the birefringence. Finally, with the first-order red compensator, the type of elongation is detected, positive for calcium pyrophosphate (CPP) crystals and negative for monosodium urate (MSU) crystals. Finally, with the obtained data, the presence and type of crystals is concluded.Objectives:Analyze the validity and agreement of each stage of microscopy regarding the conclusion, emphasizing ordinary light microscopy.Methods:Fifty consecutive samples of synovial fluid obtained in routine clinical practice were independently analyzed under the compensated polarized microscope by 5 observers blinded to clinical data (250 observations in total). Each observer recorded the presence and type of crystals at each stage and reached a conclusion after gathering all the information. To estimate the diagnostic yield of each microscope stage, sensitivity, specificity and positive and negative predictive values, as well as the accuracy (number of correct observations/number of total observations), were calculated; also, the total weighted kappa was used to assess the degree of agreement with the complete protocol.Results:Main results of the study are shown in Table 1. Regarding diagnostic yield, ordinary light microscopy showed excellent sensitivity, specificity and predictive values, similar to the results noted with simple and compensated polarized microscopy.Table 1.In parentheses, 95% confidence intervals.AccuracySensitivitySpecificityPositive predictive valueNegative predictive valueKappaOrdinary light96.8%(93.8-98.4)97.2%(93.1-98.9)96.2%(90.7-98.5)97.2%(93.1-98.9)96.2%(90.7-98.5)0.954(0.919-0.989)Simple polarized light92.0%(88.0-94.8)84.1%(76.8-89.5)100%(97.0-100)100%(96.5-100)86.1%(79.5-90.8)0.874(0.821-0.927)Compensated polarized light97.6 %(94.9-98.9)95.5%(89.8-98.0)99.3%(96.1-99.9)99.1%(94.8-99.8)96.5%(92.1-98.5)0.962(0.933-0.992)Diagnoses established by ordinary light microscopy matched conclusions (accuracy) in 242/250 (96.8%) observations. Discrepant cases were crystals missed under ordinary light in 4 cases (3 MSU, 1 CPP), and 4 samples with CPP crystals initially seen but later concluded their absence. Interestingly, lowest accuracy was seen with simple polarization; CPP crystals were not detected in 20 out of 93 observations with CPP (21.5%). The accuracy of compensated polarized light was similar to ordinary light. On 5 occasions no crystals were seen but finally they were present (1 MSU, 4 CPP); on the contrary, CPP was registered in one observation but the conclusion indicated no crystals.Regarding agreement with the complete protocol, the kappa with simple light is 0.954, similar to compensated polarized light (0.962), while simple polarized light showed the lowest agreement (0.874).Conclusion:Ordinary light microscopy is enough to correctly reach the majority of diagnoses, with a very high degree of agreement with the complete protocol. Results were comparable to using a compensated polarized microscopy. Thus, if a microscope with polarizer and first-order compensator was not available, using ordinary light would be enough on most occasions. Polarized light microscopy better identifies MSU crystals, but over 20% of CPP crystals were missed at this stage, reinforcing the value of the ordinary light microscopy.Acknowledgments:Thanks to Loreto Carmona for the help with the statistical aspects.Disclosure of Interests: :None declared

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Ultrasound for the diagnosis of gout—the value of gout lesions as defined by the Outcome Measures in Rheumatology ultrasound group

Rheumatology ◽

10.1093/rheumatology/keaa366 ◽

2020 ◽

Vol 60 (1) ◽

pp. 239-249

Author(s):

Sara Nysom Christiansen ◽

Mikkel Østergaard ◽

Ole Slot ◽

Viktoria Fana ◽

Lene Terslev

Keyword(s):

Outcome Measures ◽

Predictive Value ◽

Reference Standards ◽

Secondary Outcome ◽

Predictive Values ◽

Ultrasound Findings ◽

Ultrasound Assessment ◽

Sensitivity Specificity ◽

Ultrasound Group ◽

Msu Crystals

Abstract Objective To evaluate ultrasound for diagnosing gout using consensus-based Outcome Measures in Rheumatology ultrasound definitions of gout lesions. Methods Ultrasound was performed in patients with clinically suspected gout. Joints (28) and tendons (26) were binarily evaluated for the Outcome Measures in Rheumatology gout lesions—double contour (DC), tophus, aggregates and erosions. Ultrasound assessment was compared with two reference standards: (i) presence of MSU crystals in joint/tophus aspirate (primary outcome) and (ii) ACR/EULAR 2015 gout classification criteria (secondary outcome). Both reference standards were evaluated by rheumatologists blinded to ultrasound findings. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of each ultrasound lesion against both reference standards were determined. Results Eighty-two patients (70 men), mean age 62.4 (range 19–88) years, were included. Fifty-seven patients were MSU-positive whereas 25 patients were MSU-negative (no MSU crystals: 23; aspiration unsuccessful: 2). Of these 25 patients, three patients were classified as ACR/EULAR-positive (i.e. totally 60 ACR/EULAR-positive patients). All ultrasound lesions had high sensitivities for gout (0.77–0.95). DC and tophus showed high specificities (0.88–0.95), positive predictive values (0.94–0.98) and accuracies (0.82–0.84) when both reference standards were used. In contrast, low specificities were found for aggregates and erosions (0.32–0.59). Ultrasound of MTP joints for DC or tophus, knee joint for DC and peroneus tendons for tophus was sufficient to identify all MSU-positive patients with ultrasound signs of gout at any location. Conclusion Ultrasound-visualized DC and tophus, as defined by the Outcome Measures in Rheumatology ultrasound group, show high specificities, positive predictive values and accuracies for diagnosing gout and are therefore valid tools in clinical practice.

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Diagnostic yield of transbronchial needle aspiration for lymphoma

South African Respiratory Journal ◽

10.7196/sarj.2016.v22i3.80 ◽

2016 ◽

Vol 22 (3) ◽

pp. 67

Author(s):

B Sonnekus ◽

J Steenkamp ◽

M Louw ◽

C F N Koegelenberg

Keyword(s):

Predictive Value ◽

Diagnostic Yield ◽

Cost Effective ◽

Final Diagnosis ◽

Needle Aspiration ◽

Tracheobronchial Tree ◽

Transbronchial Needle Aspiration ◽

Predictive Values ◽

Hilar Adenopathy ◽

Sensitivity Specificity

Background. Transbronchial needle aspiration (TBNA) is a minimally invasive bronchoscopic technique that is cost-effective and safe for diagnosing mediastinal and hilar adenopathy in lung cancer, other malignancies, sarcoidosis and infectious processes such as tuberculosis. Few studies have analysed the sensitivity, specificity and predictive values of TBNA for diagnosing lymphoma.Objective. To evaluate the diagnostic yield of TBNA for diagnosing mediastinal and hilar adenopathy in suspected lymphoma.Methods. We performed a retrospective analysis of collected data of patients with mediastinal and hilar adenopathy adjacent to the tracheobronchial tree detected by thoracic computed tomography, who underwent TBNA at Tygerberg Hospital between July 2010 and June 2013. We included 25 patients with suspected or proven lymphoma. Histology was used as the gold standard.Results. Adequate samples for cytological evaluation were obtained for 22 (88%) patients. Cytological diagnosis was possible for 8 (32%). For 17 (68%) who could not be diagnosed by TBNA alone, histology provided final diagnosis. Rapid on-site examination (ROSE) was performed in 23 (92%). In 17/23 (74%) cases, these had similar results to formal cytology. Only 4 (16%) had flow cytometry requested. Twelve (48%) had lymphoma confirmed on histology. TBNA cytology had 100% specificity and positive predictive value for suspicion of lymphoma. Sensitivity was 33% and negative predictive value 62%.Conclusion. TBNA is an appropriate first-line diagnostic procedure in evaluating mediastinal and hilar lymphadenopathy in suspected lymphoma. Biopsy should be the immediate second-line procedure when ROSE/cytology is suspicious of lymphoma or shows atypical cells. Patients with negative TBNA cytology, but high clinical or radiological suspicion of lymphoma, should be further investigated.

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Foundational Statistical Principles in Medical Research: Sensitivity, Specificity, Positive Predictive Value, and Negative Predictive Value

Medicina ◽

10.3390/medicina57050503 ◽

2021 ◽

Vol 57 (5) ◽

pp. 503

Author(s):

Thomas F. Monaghan ◽

Syed N. Rahman ◽

Christina W. Agudelo ◽

Alan J. Wein ◽

Jason M. Lazar ◽

...

Keyword(s):

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Medical Literature ◽

Disease Prevalence ◽

Positive Test Result ◽

Predictive Values ◽

Sensitivity Specificity ◽

Test Result ◽

Test Probability

Sensitivity, which denotes the proportion of subjects correctly given a positive assignment out of all subjects who are actually positive for the outcome, indicates how well a test can classify subjects who truly have the outcome of interest. Specificity, which denotes the proportion of subjects correctly given a negative assignment out of all subjects who are actually negative for the outcome, indicates how well a test can classify subjects who truly do not have the outcome of interest. Positive predictive value reflects the proportion of subjects with a positive test result who truly have the outcome of interest. Negative predictive value reflects the proportion of subjects with a negative test result who truly do not have the outcome of interest. Sensitivity and specificity are inversely related, wherein one increases as the other decreases, but are generally considered stable for a given test, whereas positive and negative predictive values do inherently vary with pre-test probability (e.g., changes in population disease prevalence). This article will further detail the concepts of sensitivity, specificity, and predictive values using a recent real-world example from the medical literature.

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Value and Diagnostic Efficacy of Fetal Morphology Assessment Using Ultrasound in A Poor-Resource Setting

Diagnostics ◽

10.3390/diagnostics9030109 ◽

2019 ◽

Vol 9 (3) ◽

pp. 109 ◽

Cited By ~ 1

Author(s):

Ukweh ◽

Ugbem ◽

Okeke ◽

Ekpo

Keyword(s):

Predictive Value ◽

Performance Metrics ◽

Area Under The Curve ◽

Youden Index ◽

Likelihood Ratios ◽

Diagnostic Efficacy ◽

Predictive Values ◽

Resource Setting ◽

Post Test ◽

Sensitivity Specificity

Background: Ultrasound is operator-dependent, and its value and efficacy in fetal morphology assessment in a low-resource setting is poorly understood. We assessed the value and efficacy of fetal morphology ultrasound assessment in a Nigerian setting. Materials and Methods: We surveyed fetal morphology ultrasound performed across five facilities and followed-up each fetus to ascertain the outcome. Fetuses were surveyed in the second trimester (18th–22nd weeks) using the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) guideline. Clinical and surgical reports were used as references to assess the diagnostic efficacy of ultrasound in livebirths, and autopsy reports to confirm anomalies in terminated pregnancies, spontaneous abortions, intrauterine fetal deaths, and still births. We calculated sensitivity, specificity, positive and negative predictive values, Area under the curve (AUC), Youden index, likelihood ratios, and post-test probabilities. Results: In total, 6520 fetuses of women aged 15–46 years (mean = 31.7 years) were surveyed. The overall sensitivity, specificity, and AUC were 77.1 (95% CI: 68–84.6), 99.5 (95% CI: 99.3–99.7), and 88.3 (95% CI: 83.7–92.2), respectively. Other performance metrics were: positive predictive value, 72.4 (95% CI: 64.7–79.0), negative predictive value, 99.6 (95% CI: 99.5–99.7), and Youden index (77.1%). Abnormality prevalence was 1.67% (95% CI: 1.37–2.01), and the positive and negative likelihood ratios were 254 (95% CI: 107.7–221.4) and 0.23 (95% CI: 0.16–0.33), respectively. The post-test probability for positive test was 72% (95% CI: 65–79). Conclusion: Fetal morphology assessment is valuable in a poor economics setting, however, the variation in the diagnostic efficacy across facilities and the limitations associated with the detection of circulatory system anomalies need to be addressed.

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Prediction of preeclampsia using a combination of serum micro RNA-210 and uterine artery Doppler ultrasound

Science Progress ◽

10.1177/00368504211036856 ◽

2021 ◽

Vol 104 (3) ◽

pp. 003685042110368

Author(s):

Ananya Trongpisutsak ◽

Vorapong Phupong

Keyword(s):

Pregnant Women ◽

Doppler Ultrasound ◽

Predictive Value ◽

Early Onset ◽

Uterine Artery ◽

Micro Rna ◽

Predictive Values ◽

Uterine Artery Doppler ◽

Early Onset Preeclampsia ◽

Sensitivity Specificity

The objective was to determine whether a combination of serum micro RNA-210 level and uterine artery Doppler can predict preeclampsia in pregnant women at 16–24 weeks gestation. A prospective observational study conducted in singleton pregnant women at 16–24 weeks of gestation who had prenatal care at the King Chulalongkorn Memorial Hospital, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand between 2017 and 2018. Uterine artery Doppler ultrasound and blood testing for serum micro RNA-210 were performed. Pregnancy outcomes were recorded. Optimal cut-off for uterine artery pulsatility index (PI) and serum micro RNA-210 were obtained to calculate the predictive values for preeclampsia. Data from 443 participants were analyzed. Twenty-two cases developed preeclampsia (5.0%) and seven of these preeclamptic cases had early-onset preeclampsia (1.6%). Pregnant women with preeclampsia had higher mean PI of the uterine artery (1.34 ± 0.52 vs 0.98 ± 0.28, p = 0.004), higher detection rates of diastolic notching (45.5% vs 11.2%, p < 0.001), and lower median serum micro RNA-210 level (22.86 vs 795.78, p < 0.001) than pregnant women without preeclampsia. Using abnormal serum micro RNA-210 level, abnormal mean PI or uterine artery diastolic notches to predict for preeclampsia, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 95.5%, 54.9%, 10.0%, and 99.6%, respectively. For early-onset preeclampsia prediction, the sensitivity, specificity, PPV, and NPV were 100.0%, 53.2%, 3.3%, and 100.0%, respectively. This study demonstrated that a combination of serum micro RNA-210 and uterine artery Doppler is effective in predicting preeclampsia in the second trimester.

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Gicht und Calciumpyrophosphat-Dihydrat-Arthropathie („Pseudogicht“) – ein Update

DMW - Deutsche Medizinische Wochenschrift ◽

10.1055/a-0504-5684 ◽

2018 ◽

Vol 143 (16) ◽

pp. 1157-1166 ◽

Cited By ~ 1

Author(s):

Monika Reuss-Borst ◽

Anne-Kathrin Tausche

Keyword(s):

Light Microscopy ◽

Metabolic Diseases ◽

Polarized Light ◽

Diagnostic Algorithm ◽

Serum Urate ◽

Diagnostic Tools ◽

Monosodium Urate ◽

Crystal Arthropathies ◽

Ordinary Light ◽

Special Circumstances

AbstractThe metabolic diseases gout and calciumpyrophosphate deposition (CPPD) (formerly: chondrocalcinosis/pseudogout) are crystal arthropathies which are caused by crystals in synovial fluid and in the case of gout also in periarticular structures. Today, in particular gout is considered as an auto-inflammatory process since phagocytosis of monosodium urate crystals by monocytes/macrophages results in the activation of the innate immune system by activation of the NRLP3-Inflammasome and consecutive secretion of the key cytokine interleukin-1ß and other pro-inflammatory cytokines. The prevalence of both crystal arthropathies rises with increasing age of patients. Most often they present clinically as an acute monarthritis of different locations. Beside typical clinical presentation, performance of ultrasonography, conventional X-Ray of joints and under special circumstances dual-energy-computer tomography could be also helpful diagnostic tools. There are EULAR guidelines describing the diagnostic algorithm for making right diagnosis. The arthrocentesis with microscopic detection of crystals is established diagnostic gold standard. Whereas crystals of monosodium urate could be very clearly be seen as relatively large intra- and extracellular needles with a strong birefringence in polarized light microscopy the detection of CPPD-crystals is more difficult. Those crystals are much smaller, showing weaker birefringence and are sometimes only seen with ordinary light microscopy. As both crystal diseases are mediated by IL-1 driven processes, the therapeutic intervention first target the acute inflammation consisting in colchicine, NSAIDs and glucocorticoids. Secondarily, in gout there are well established causal therapies to lower effectively serum urate levels below the target of 6 mg/dL (360 µmol/l). Unfortunately, those causal therapeutic options are still lacking in CPPD.

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Clinical Performance of the Spot Vision Photo Screener before and after Induction of Cycloplegia in Children

Journal of Ophthalmology ◽

10.1155/2019/5329121 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Konuralp Yakar

Keyword(s):

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Clinical Performance ◽

High Specificity ◽

Screening Criteria ◽

Predictive Values ◽

Before And After ◽

Sensitivity Specificity ◽

Vision Screener

Aim. To compare the clinical performance of the Spot Vision Screener used to detect amblyopia risk factors (ARFs) in children before and after induction of cycloplegia; the children were referred because they met the screening criteria of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS). Methods. The Spot Vision Screener and a standard autorefractometer were used to examine 200 eyes of 100 children aged 3–10 years, before and after cycloplegia induction, in terms of ARFs. Sensitivity, specificity, and positive and negative predictive values for the detection of significant refractive errors were measured using the AAPOS referral criteria. It was explored that Spot Screener data were affected by cycloplegia. The extent of agreement between cycloplegic/noncycloplegic photoscreening data and cycloplegic autorefraction measurements was assessed using Wilcoxon and Spearman correlation analyses. Results. The Spot’s sensitivity was improved from 60.9% to 85.3% and specificity from 94.9% to 87.4% with cycloplegia compared to cycloplegic standard autorefractometer results. The positive predictive value of Spot was 75.7%, and the negative predictive value was 90.4% without cycloplegia. With cycloplegia, the positive predictive value of Spot was 63.6% and the negative predictive value was 95.8%. Conclusions. The Spot Screener afforded moderate sensitivity and high specificity prior to cycloplegia. The sensitivity and negative predictive value improved after induction of cycloplegia. Examiners should be aware of the effects of cycloplegia on their findings.

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An assessment of chromosomal alterations detected by fluorescence in situ hybridisation in pancreatobiliary tract malignancy

BMC Gastroenterology ◽

10.1186/s12876-020-01439-0 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Xiaohong Pu ◽

Hongwei Zheng ◽

Xin Yang ◽

Qing Ye ◽

Zhiwen Fan ◽

...

Keyword(s):

Predictive Value ◽

In Situ Hybridisation ◽

False Negative ◽

Chinese Patients ◽

Fluorescence In Situ Hybridisation ◽

Predictive Values ◽

Formalin Fixed Paraffin Embedded ◽

9P21 Locus ◽

Sensitivity Specificity

Abstract Background Using fluorescence in situ hybridisation (FISH) to detect any gain of chromosomes 3, 7, or 17 and loss of the 9p21 locus has been proven to be sensitive in the diagnosis of pancreatobiliary tumors. However, both genetic and environmental factors contribute to the pathogenesis of pancreatobiliary tumors. Therefore, it is unknown whether this method is suitable for Chinese patients with pancreatobiliary tumors. This study aims to compare the sensitivity, specificity, predictive values and accuracy of cytology, ERCP/MRCP and FISH based on Chinese patients with pancreatobiliary tumors,and to analyze differences between brushing-based and formalin-fixed paraffin-embedded (FFPE)-based FISH. Methods A total of 66 brush cytology specimens obtained during ERCP were detected by FISH and cytology test respectively to compare the sensitivity, specificity, predictive values and accuracy. Besides, FFPE-based FISH was performed on 46 corresponding paraffin sections of pancreatobiliary tumors obtained by surgical resection. Results Our findings demonstrate that FISH greatly improves diagnostic sensitivity and negative predictive value compared to ERCP/MRCP and cytology without much reduction in specificity and positive predictive value. However, our results also indicate that FFPE-based FISH could not effectively identify the false-negative of brushing-based FISH. Conclusions We believe that FISH can effectively distinguish true positive and false positive results of cytological or radiological suspicions of malignancy. However, FFPE-based FISH still does not precisely recognize the false-negative of brushing-based FISH. Both cytology-based and PPFE-based FISH had limitation in some specimens.

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Persistence of Crystals in Stored Synovial Fluid Samples

The Journal of Rheumatology ◽

10.3899/jrheum.190468 ◽

2020 ◽

Vol 47 (9) ◽

pp. 1416-1423

Author(s):

Sonia Pastor ◽

José-Antonio Bernal ◽

Rocío Caño ◽

Silvia Gómez-Sabater ◽

Fernando Borras ◽

...

Keyword(s):

Synovial Fluid ◽

Light Microscopy ◽

Room Temperature ◽

Polarized Light ◽

Calcium Pyrophosphate ◽

Polarized Light Microscopy ◽

Tetraacetic Acid ◽

Monosodium Urate ◽

Prospective Longitudinal ◽

Msu Crystals

Objective.Lack of access to polarized light microscopy is often cited as an argument to justify the clinical diagnosis of crystal-related arthritis. We assessed the influence of time since sampling and preservation methods on crystal identification in synovial fluid (SF) samples under polarized light microscopy.Methods.This was a prospective, longitudinal, observational factorial study, analyzing 30 SF samples: 12 with monosodium urate (MSU) crystals and 18 with calcium pyrophosphate (CPP) crystals. Each SF sample was divided into 4 subsamples (120 subsamples in total). Two were stored in each type of preserving agent, heparin or ethylenediamine tetraacetic acid (EDTA), at room temperature or at 4°C. Samples were analyzed the following day (T1), at 3 days (T2), and at 7 days (T3) by simple polarized light microscopy, and the presence of crystals was recorded.Results.The identification of crystals in the MSU group was similar between groups, with crystals observed in 11/12 (91.7%) room temperature samples and in 12/12 (100%) refrigerated samples at T3. Identification of CPP crystals tended to decrease in all conditions, especially when preserved with EDTA at room temperature [12/18 (66.7%) at T3], while less reduction was seen in refrigerated heparin-containing tubes.Conclusion.Preserving samples with heparin in refrigerated conditions allows delayed microscopic examination for crystals. Avoiding crystal-proven diagnosis because of the immediate unavailability of microscopy no longer appears justified.

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Molecular testing (strand displacement assay) for identification of urethral gonorrhoea in men: can it replace culture as the gold standard?

International Journal of STD & AIDS ◽

10.1258/0956462054094079 ◽

2005 ◽

Vol 16 (6) ◽

pp. 430-432 ◽

Cited By ~ 2

Author(s):

H L Wheeler ◽

C J Skinner ◽

A Khunda ◽

C Aitken ◽

D Perpanthan ◽

...

Keyword(s):

Predictive Value ◽

Diagnostic Yield ◽

Molecular Testing ◽

Strand Displacement ◽

Specific Test ◽

Strand Displacement Amplification ◽

Conventional Culture ◽

Study Population ◽

Displacement Assay ◽

Sensitivity Specificity

The objective was to evaluate the performance of Becton Dickinson's BD Probe TecTM (BDPT) strand displacement amplification (SDA) test for the detection of Neisseria gonorrhoeae on urethral specimens from men with urethritis compared with conventional culture and to show that SDA improves the diagnostic yield of gonorrhoea infections (GC). Anonymized retrospective testing of stored urethral swab samples from men attending genitourinary services in East London was performed using SDA. The prevalence of GC culture positive infections in this sample was 20/152 (13%). The sensitivity, specificity, positive predictive value and negative predictive value for the BDPT-SDA system compared with culture were 100%, 95%, 77% and 100%, respectively. In this study population, the BDPT-SDA assay was a highly sensitive and specific test for the diagnosis of N. gonorrhoeae from urethral swabs in men. Therefore, SDA can be used to complement culture in the diagnosis of N. gonorrhoeae infection. No ethics committee approval was obtained as all samples were anonymized.

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