Indeterminate Results Research Articles

SARS-CoV-2 in mink farms in British Columbia, Canada: A report of two outbreaks in 2020-2021.

Since April 2020, mink have been recognized as a potential reservoir for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and a potential source of new variants. The objective of this report is to describe the epidemiological investigation and public health response to two coronavirus disease 2019 (COVID-19) outbreaks that involved both humans and farmed mink. An outbreak was declared on December 4, 2020, following detection of two COVID-19-positive farmworkers and elevated mink mortality on a mink farm (Farm 1) in British Columbia. The second cluster was detected on Farm 3 following detection of 1) a COVID-19 case among farm staff on April 2, 2021, 2) an indeterminate result from farm staff on May 11, 2021, and 3) subsequent SARS-CoV-2-positive mink in May 2021. Quarantine of infected farms, isolation of workers and their close contacts, and introduction of enhanced infection control practises were implemented to break chains of transmission. Among mink farmworkers, 11 cases were identified at Farm 1 and 6 cases were identified at Farm 3. On both Farm 1 and Farm 3, characteristic COVID-19 symptoms were present in farm employees before signs were observed in the minks. The viral sequences from mink and human samples demonstrated close genetic relation. Phylogenetic analyses identified mink intermediates linking human cases, suggesting anthropo-zoonotic transmission. These were the first COVID-19 outbreaks that included infected mink herds in Canada and identified potential anthropogenic and zoonotic transmission of SARS-CoV-2. We provide insight into the positive impact of regulatory control measures and surveillance to reduce the spillover of SARS-CoV-2 mink variants into the general population.

Basophil activation test as alternative method to CAP-inhibition in patients with double sensitization to vespid venoms

Most patients with Hymenoptera venom allergy (HVA) to vespid venoms present double sensitization by specific IgE (sIgE)-mediated cross-reactivity. Thus, it is mandatory could discriminate between a true double and primary sensitization to implement an accurate venom-specific immunotherapy (VIT). To date, CAP-inhibition is the reference method in the diagnosis of cross-reactivity in double sensitized patients to vespid venoms, being the results obtained with the component resolved diagnostics (CRD) conflicting. For this, we have studied in a cohort of double sensitized patients to Vespula vulgaris (VV) and Polistes dominulus (PD) venoms (n = 40) the diagnostic accuracy of CRD using the CAP-inhibition as reference method, as well as to investigate whether basophil activation test (BAT) is an alternative method for inconclusive results obtained by CAP-inhibition. CAP-inhibition showed a sensitivity of 59.46 % in view of the indeterminate results; most patients had true double sensitization (54.5 %), followed by single sensitization to PD (27.27 %) and VV (18.18 %) venoms. CRD based on rVes v 5/rPol d 5 (or vice versa) ratio as well as whole extracts I3/I77 (or vice versa) ratio (specific IgE-I3 to VV/specific IgE-I77 to PD) showed a low diagnostic accuracy (AUC = 0.504, p = 0.974; AUC = 0.35, p = 0.235; respectively). BAT was determined in parallel with CAP-inhibition in 12 patients, presented higher sensitivity than CAP-inhibition (p = 0.021) and a positive agreement of 71.43 %. Likewise it was able to identify 100% of inconclusive results, showing a specificity of 83.3 %. Therefore, CRD is not a suitable method to distinguish monosensitization and BAT appears to be an appropriate method resolving indeterminate results from the gold standard method.

#11 Development of a Kinetic ELISA (kELISA) and Reactive B Cell Frequency (RBF) Assay to Detect Respiratory Syncytial Virus (RSV) Pre-Fusion F Protein-Specific Immune Responses in Infants

Abstract Background RSV is a major cause of pediatric respiratory disease. Antibodies to the prefusion conformation of the RSV fusion (pre-F) protein are needed for virus neutralization. Method We measured RSV-specific responses in two groups of children <3 years of age; subjects with laboratory-confirmed RSV (RSV-infected) or infants born in the period May to September and enrolled prior to their first RSV season (RSV-uninfected). RSV-infected infants had blood samples obtained at 1, 6, 9, and 12 months after infection. RSV-uninfected infants had blood samples obtained at enrollment, at the end of their first RSV season, and 6 months later. A kELISA to measure RSV pre-F-specific antibodies and an RBF assay to identify RSV F-specific B cells were developed. Results 102 subjects were enrolled; 11 were excluded due to missed visits or withdrawal. Of the 65 subjects in the RSV-uninfected group, all were kELISA positive at enrollment, consistent with maternal antibody transfer. 53 subjects had sufficient samples for analysis at multiple time points; 29 became seronegative and 24 remained seropositive. In the seronegative group, the kELISA value decreased rapidly to <0.25 by 6 months after the RSV season in 27/29 (93%), (Figure 1a). In the persistently seropositive group, all 24 subjects maintained a positive kELISA value, with some developing higher values over time, consistent with asymptomatic infection (Figure 1b). An RBF assay was used to determine whether antibodies were due to persistent maternal antibodies or endogenous production (Figure 1c). In the seronegative group, 24/29 (80%) had a negative RBF; in the seropositive group, 23/24 (96%) had a positive RBF during follow-up. There were 26 subjects in the RSV-infected group; 22 had sufficient samples for analysis at multiple time points. All were seropositive by kELISA at one month post-infection with variable kELISA values during follow-up (Figure 1d). 17/22 (77%) had a positive RBF, although 4 of the subjects without a positive RBF had indeterminate results at ≥ 1 visit. Conclusion Assays measuring F-specific immune responses in infants will be critical for RSV vaccine development. A kELISA targeting RSV pre-F epitopes, with an RBF assay targeting RSV F-specific B cells, may allow discrimination for maternal and infant-derived antibodies.

Indeterminate results of QuantiFERON-TB Gold in-tube due to high nil concentration and methodological exploration and improvement

BackgroundThe features of indeterminate results (ITRs) due to high interferon gamma (IFN-γ > 8.0 IU/mL) concentrations in Nil tubes of QuantiFERON-TB Gold in-Tube (QFT-GIT) have not been well studied. Therefore, this study aimed at investigating the features of ITRs and optimization alternatives for this method. MethodsWe used the plasma exchange method to reduce the ITR rate due to high Nil concentrations (Nil > 8.0 IU/mL) between March 2020 and September 2021 at Xiangya Hospital of Central South University in China. One hundred and eleven out of 28,193 patient samples were considered ITRs due to Nil > 8.0 IU/mL. Of these 111, blood was re-sampled from 82 patients (pretreated group) who received the plasma exchange. Moreover, 40 out of 82 (blood volume ≥ 5 mL) received pretreated QFT-GIT and standard QFT-GIT (untreated group) simultaneously, while the remaining 42 received pretreated QFT-GIT only. The statistical difference between groups was evaluated. Cohen’s kappa coefficient was used to assess the level of agreement between the pretreated and untreated group. ResultsOf the 28,193 subjects, 1,083 (3.8%) had ITRs, and 111 (0.4%) had ITRs due to Nil > 8.0 IU/mL. The population studied had a mean age of 52.9 years, and 70.3% were men, which is a larger proportion than that in patients with ITR and the overall population. Significantly decreased IFN-γ levels in Nil tubes were detected using the pretreated QFT-GIT compared with standard QFT-GIT (p < 0.01). The determinate results rate in the pretreated group was significantly higher than that of the untreated group (80% (32/40) vs 57.5%, (23/40), p = 0.03). Further comparison revealed that the pretreated group was consistent with the untreated group in 17/20 (85%) positive tests, 3/3 (100%) negative tests, and 6/17 (35.3%) ITRs. The overall agreement rate was 26/40 (65%) among all 40 subjects, and the κ value was 0.39 (minimal agreement). The majority of results obtained after pretreatment were positive (71.2%, 59/82) and the agreement rate between clinical diagnosis and pretreated QFT-GIT was at least 61.0% (39/59). ConclusionPlasma exchange pretreated QFT-GIT yields more reliable results than untreated QFT-GIT when processing high Nil concentrations.

Comparison of diagnostic accuracy of QuantiFERON‐TB Gold Plus and T‐SPOT.TB in the diagnosis of active tuberculosis in febrile patients

ObjectiveThis study aimed to compare the accuracy of QuantiFERON‐TB Gold Plus (QFT‐Plus) and T‐SPOT.TB for diagnosing active tuberculosis (ATB) in febrile patients, to explore influencing factors of positive results and to verify the potential value of QFT‐Plus in the identification of ATB and latent tuberculosis infection (LTBI).MethodsA total of 240 febrile patients with ATB (n = 80) and non‐ATB (n = 160) were recruited to assess the accuracy of QFT‐Plus and T‐SPOT.TB for diagnosing ATB. Multivariable logistic regression was used to analyze the influencing factors of positive results.ResultsThe proportion of indeterminate results (ITRS) in QFT‐Plus and T‐SPOT.TB were 3.3% and 0%, respectively. The consistency between the results of the QFT‐Plus and T‐SPOT.TB was substantial. The area under the receiver operating characteristic curve (AUROC) of the QFT‐Plus and T‐SPOT.TB for diagnosing ATB was 0.792 and 0.849 (p = 0.070), respectively. The sensitivity of differentiating ATB from non‐ATB was 92.2% in QFT‐Plus versus 95.0% in T‐SPOT.TB. The influencing factors of T‐SPOT.TB positive result were male (odds ratio (OR) = 2.33, 95% confidence interval (CI) 1.27–4.26, p = 0.006), evidence of previous TB (OR 11.36, 95% CI 4.62–27.94, p < 0.001), while male (OR = 3.17, 95% CI 1.73–5.84, p < 0.001), evidence of previous TB (OR = 7.58, 95% CI 3.60–15.98, p <0.001), and use of immunosuppressant (OR = 0.49, 95% CI 0.260.94, p = 0.030) were influencing factors for QFT‐Plus positive result. There was no significant difference in QFT‐Plus in differentiating ATB from LTBI in febrile patients.ConclusionThere was no significant difference between QFT‐Plus and T‐SPOT.TB for diagnosing ATB in febrile patients. QFT‐Plus is prone to ITRS. The influencing factors including males, evidence of the previous TB, and use of immunosuppressant should be considered when interpreting positive results.

Usefulness of cellblock preparation in fine needle aspiration for the diagnosis of thyroid nodules.

Thyroid nodules are common in the general population. The current diagnostic method for nodules is the ultrasound guided fine needle aspiration (US-FNA). The aim of the study was to evaluate the usefulness of cellblock preparation in addition to routine US-FNA in the diagnosis of thyroid nodules. A retrospective study of patients with thyroid nodules submitted to US-FNA, with collection of material using both smears and cellblock preparation. Two air-dried smears were prepared for each nodule. After centrifugation, the residual aspirate in the syringe and needle was processed as a standard histology specimen (cellblock). Then a pathologist reviewed the smears and cellblock slides of each case. A total of 12.360 thyroid nodules were submitted to US-FNA. Cellblock preparation was performed in 153 (1.2%) in addition to smears. Among the satisfactory cellblocks (80.5%, 120), 31.7% (38) provided additional morphological information in comparison with smears alone. No significant differences were found between the smear and the combined smear and cellblock evaluation concerning the number of unsatisfactory (12.1% vs. 11.4%, p=.85) and indeterminate (27.5% vs. 24.2%, p=.52) results. Overall, 10 samples (6.7%) had their diagnosis changed after cellblock evaluation, nine of them due to immunohistochemical studies. Immunohistochemistry confirmed parathyroid origin of the nodule in six cases. Cellblocks did not contribute to increase cellularity of the samples or to reduce indetermined results of FNA of thyroid nodules. Immunohistochemistry was essential to characterize rare cases without follicular histogenesis. Cellblock must only be prepared when considering performing immunohistochemistry.

SCC Antigen Concentrations in Fine-Needle Aspiration Samples to Detect Cervical Lymph Node Metastases: A Prospective Analysis.

To determine the diagnostic value of measuring squamous cell carcinoma antigen (SCC-Ag) and cancer antigen 15-3 (CA15-3) concentrations in fine-needle aspiration (FNA) samples for the detection of squamous cell carcinoma (SCC) metastases in cervical lymph nodes. A prospective study with patients consecutively included between November 2018 and May 2021. A tertiary head and neck oncologic center. Out of 138 patients, SCC-Ag concentrations were analyzed in 168 FNA cervical lymph node samples and CA15-3 in 152 samples. Results were compared with FNA cytology (FNAC) or definitive histology to establish sensitivity and specificity rates. For the detection of cervical SCC lymph node metastases, SCC-Ag measurement had an 89.4% sensitivity and 79.3% specificity at a cutoff concentration of 0.1 µg/L. Measurement of CA15-3 concentration in addition to SCC-Ag concentration did not lead to improved accuracy for the detection of SCC. In histology-confirmed cases, FNAC had an 80.0% sensitivity and 100% specificity, as opposed to 93.3% and 57.1%, respectively, for SCC-Ag. Measurement of SCC-Ag concentration for detection of SCC lymph node metastases has a sensitivity at least comparable to FNAC and could be used as a relatively cheap screening tool in samples with nondiagnostic or indeterminate FNAC results or when multiple lymph nodes are sampled. However, SCC-Ag in FNA samples has a lower specificity than FNAC assessed by pathologists experienced in head and neck oncology. Addition of CA15-3 measurement did not lead to improved accuracy.

Perfusion lung scans during the pandemic: COVID-19 experience in a large trauma hospital

PurposeTo evaluate the results of perfusion only lung scans and the frequency of necessary addition of the ventilation part of the scans to diagnose acute pulmonary embolism (PE) during Corona Virus Disease of 2019 (COVID 19) pandemic. Material and methodsWe retrospectively reviewed perfusion lung scans’ results between April to December 2020. The images were interpreted by two experienced nuclear medicine physicians as daily routine studies. Ventilation images were performed only if deemed necessary for accurate diagnosis of acute PE. ResultsA total of 128 lung perfusion scans in 127 patients were included. The scans were interpreted with certainty using the modified PIOPID criteria in 122 patients (95.3%). The results included low probability for acute PE in 110 patients (85.9%), normal in 6 patients (4.7%) and high probability of acute PE in 6 patients (4.7%). Ventilation imaging were performed in 4 patients with high probability, after negative testing for COVID19. The other 2 high probability results were confirmed clinically and with radiologic imaging. Only 6 scans (4.7%) were interpreted as intermediate perfusion scans, two of which due to inability to differentiate old from new perfusion defects in patients with chronic thromboembolic disease. Thus, the true indeterminate results due to the lack of ventilation scan were encountered in only 4 intermediate probability lung scans (3.1%). Thus, the total number of requested ventilation scans was 8 scans (6.2%) when considering both the high and intermediate probability interpretations. Six scans were performed (2 in the intermediate and 4 in the high probability scans). The two ventilation scans performed in the intermediate probability changed the diagnosis to low probability and the four performed in the high probability confirmed the initial interpretation of high probability scans by perfusion only. ConclusionThe ventilation part of lung scans is required only in a small number of patients for certain interpretation of the result. Perfusion lung scans are sufficient for evaluation of acute PE with certainty in most patients.

The value of 99mTc-MIBI scan in the detection of malignancy potential of hypermetabolic thyroid incidentalomas of 18F-FDG PET/CT

Aim of the studyIncreasingly use of PET/CT leads to discovery of incidental findings. Hypermetabolic thyroid nodules are one of the unexpected lesions in PET/CT imaging with an increased risk of thyroid cancers. Our study aims to determine the malignant potential of incidentally detected 18F-FDG avid thyroid nodules by using Tc-99m MIBI imaging. Materials and methodsPET/CT scans were performed for nonthyroidal purposes and were evaluated for the presence of hypermetabolic thyroid nodules. Tc-99m MIBI scans and ultrasonography-guided fine needle aspiration biopsies were subsequently performed for all patients. ResultsPrimary thyroid malignancies were identified in 25% of patients with increased focal FDG uptake at definitive diagnosis. Among the patients with FDG avid thyroid nodules, Tc-99m MIBI scan showed true-positive results in all thyroid carcinomas (n:7) with a 36.3% (4/11) false-positivity rate. In three patients with indeterminate cytology results, Tc-99m MIBI scan findings were also negative. The sensitivity, specificity, positive predictive value of Tc-99m MIBI scan in predicting the malignancy of FDG-positive thyroid nodules were 100%, 77%, 63.6%, respectively. ConclusionThe implementation of 99mTc-MIBI scan performed by dual phase and SPECT/CT modality might be a helpful cost-effective approach in addition to FNAB in patients with 18F-FDG-positive thyroid nodules and indeterminate cytology to improve the patients’ prognosis and reduce unnecessary thyroid operations with associated use of FNAB.

Instrumental, Hermeneutic, and Ontological Indeterminacy in Hugh Davies’s Live Electronic Music

While many previous studies have explored indeterminacy as a compositional technique, in this article we explore the concept of indeterminacy, not only from the perspective of the composer, but also from the perspectives of performer and archival researcher, drawing upon our experiences of researching and performing several live electronic music compositions by British experimental musician Hugh Davies (1943–2005). Our core argument is that beneath the surface level of composed indeterminacy—that is, beyond the notations and instructions that a composer employs to prescribe indeterminate musical results—there exist further ‘nested’ planes of indeterminacy that reveal themselves through the acts of archival research, rehearsal and performance. ‘Instrumental’ indeterminacy has to do with the instruments that are used to perform the music, and specifically to situations where the boundaries of the instruments are experienced (by performers or audience members) as ambiguous, fluid, reconfigurable, or undefinable, or where the behaviour of the instrument(s) is unpredictable or uncontrollable in the moment of performance. ‘Hermeneutic’ indeterminacy concerns the composer’s intentions and the ways in which these are revealed, through the processes of archival and performance research, to be incompletely, ambiguously, contradictorily, and/or diffusely represented in documents (including but not limited to scores) and material configurations (including the instruments and apparatus used to perform the music). ‘Ontological’ indeterminacy is signalled by uncertainty (on the part of the researchers) about the ontological status of the piece to be performed. By sharing these perspectives, we aim to contribute to scholarly understandings of the ‘afterlives’ of indeterminacy, beyond the circumscriptions of a composer.

Serum TSH as a predictor of malignancy in indeterminate thyroid nodules.

Thyroid nodules are lesions that are radiologically distinct from the thyroid parenchyma. Cervical ultrasound diagnoses 19-67% of nodules and is crucial in identifying those that lack cytological characterisation. Approximately 25% of biopsies reveal an indeterminate cytological result (Bethesda III), in which the risk of malignancy is variable (5-15%). The clinical importance of the diagnostic strategy used for thyroid nodules results from the need to exclude malignancy. The aim of this study was to evaluate the usefulness of serum thyroid-stimulating hormone (TSH) levels as a predictor of malignancy in cytologically indeterminate thyroid nodules. Our retrospective study included 40 patients with cytologically indeterminate thyroid nodules seen in our hospital between January 2013 and December 2017. Clinical parameters were reviewed, including age, gender, serum TSH levels, family history of thyroid carcinoma, radiation exposure and some sonographic features of the nodules. Statistical analysis was performed using SPSS. Statistical significance was defined as p<0.05. Female gender was predominant (85%) and the mean (SD) age was 53.3 (15) years. Thyroid carcinoma was confirmed in 28% of patients. Median TSH levels were higher in patients with malignant (2.73µIU/ml) compared with benign (1.56µIU/ml) nodules (p<0.05). We demonstrated an increased risk of malignancy in patients with TSH levels of 2.68µIU/ml or above (p<0.05). Higher serum TSH levels are associated with an increased risk of thyroid carcinoma in cytologically indeterminate nodules. TSH can become a fundamental diagnostic tool in stratifying the risk of malignancy and assist in diagnostic and therapeutic approaches to these nodules.

Evaluation and adjustment of screening algorithms for HBV, HCV, HIV and syphilis in an anatomical donation program for undergraduate education

Study objectiveUndergraduates and other users of anatomical donors are at risk of exposure to bloodborne pathogens. This study evaluated screening algorithms for hepatitis B and C virus, human immunodeficiency virus and Treponema pallidum during donor allocation and assessed the impact of postmortem time on hemolysis and how hemolysis affects test results and donor discard rate.MethodsFrom 2011‐2018, demographic data of donors, time of postmortem blood sampling, presence of sample hemolysis, serological test results (negative; active infection; false reactive screening test; historic infection; inconclusive; technically impracticable) and the actual donor allocation were collected.ResultsDonors (n=537) had a mean age of 77.53±13.67 year. Nine (1.68%) had test results indicative for active infection for hepatitis B (n=1) and C virus (n=2), human immunodeficiency virus (n=5) and Treponema pallidum (n=1). Negative screenings ranged from 74.67 to 97.58%, depending on the pathogen. Based on the screening algorithms, 479 (89.20%) donors should have been accepted. In practice, a donor acceptance rate of 91.20% was found. Analysis of potential donor allocation interpretation obstacles resulted in simplification of the testing algorithms and addition of a nucleic acid test to increase the reliability for identification of active (acute) human immunodeficiency virus infection. Hemolysis was more common when sampling was performed more than 24 hours after death (p&lt;0.001). Hemolytic samples more frequently showed a reactive or indeterminate human immunodeficiency virus test result (p&lt;0.001). Screening for human immunodeficiency virus and Treponema pallidum was technically more impracticable when hemolysis was present (p=0.042 and p=0.003, respectively). Donors with hemolytic blood samples were more often discarded (46.88%) compared to bodies with non‐hemolytic samples (6.32%) (p&lt;0.001).ConclusionsDespite the use of screening algorithms, many bodies used for undergraduate education have an inconsistent allocation. Simplified algorithms were made and are currently prospectively assessed. Early postmortem blood sampling is key as hemolysis can influence certain test results and donor allocation.

Abstract #1183817: Case Series of Two TERT Mutation-Positive Benign Follicular Thyroid Adenomas

Telomerase reverse transcriptase (TERT) promoter mutations have been found to increase telomerase activity and thereby drive oncogenic processes. TERT mutations have been identified in many types of malignancies and are frequently found in anaplastic, follicular, and papillary thyroid cancer. Genetic testing has become an important tool in evaluating thyroid lesions especially with indeterminant fine needle biopsy results. Studies have shown TERT promoter mutations to be associated with poor prognosis and are only very rarely found in benign thyroid lesions.

The role of thyroid sonographic malignancy risk features when the fine needle aspiration biopsy result is indeterminate.

Although the role of the thyroid ultrasound is well established in the initial thyroid nodule work up, it is still equivocal whether the thyroid ultrasound pattern could have an impact on refining malignancy risk after an indeterminate cytopathology result. We aim to assess the possible supportive role of the thyroid nodule ultrasound malignancy risk features listed in the Polish guidelines when a biopsy result is indeterminate. We retrospectively reviewed thyroid ultrasound scans from 175 adult patients with thyroid nodules and indeterminate cytopathology results, who underwent thyroid surgery. Sonographic malignancy risk features were reported in accordance with the guidelines of the Polish National Societies Diagnostics and Treatment of Thyroid Carcinoma and included the following: solid structure, hypoechogenicity, microcalcifications, taller than wide shape, irregular margins, features of extrathyroidal expansion, suspicious cervical lymph nodes. The malignancy risk in relevant cytological categories, estimated on the basis of histological verification, was 10.9% for Bethesda III category, 12.1% for Bethesda IV, and 71.4% for Bethesda V. The predominant type of thyroid malignancy was papillary thyroid carcinoma (79%). Thyroid nodules sonographic malignancy risk features provided high specificity but low sensitivity in selected groups of indeterminate thyroid nodules. Microcalcifications was the only characteristic that solely had a clinically relevant positive likelihood ratio (> 10) to suggest malignancy in the analysed cohort, but it was not observed in thyroid nodules eventually verified as follicular thyroid carcinoma. An accumulation of more than one sonographic risk feature yielded significant increase in malignancy risk only in Bethesda V category thyroid nodules. The impact of sonographic malignancy risk features on refining post-biopsy probability of thyroid cancer in thyroid nodule with indeterminate cytopathology, may be inadequate to sort patients (without any doubt) between those who require thyroid surgery and those who only require surveillance. There is an urgent need to search for new tools in the diagnostics of indeterminate thyroid nodules and to standardize thyroid ultrasound reports.

Diagnostic accuracy of Abbott Architect Assay as a screening tool for human T-cell leukaemia virus type-1 and type-2 infection in a London teaching hospital with a large solid organ transplant centre.

AimIn the United Kingdom, organ donors/recipients are screened for evidence of human T‐cell leukaemia virus type‐1 and type‐2 (HTLV‐1/2) infections. Since the United Kingdom is a low prevalence country for HTLV infections, a screening assay with high sensitivity and specificity is required. Samples with repeat reactivity on antibody testing are sent to a reference lab for confirmatory serological and molecular testing. In the case of donor screen, this leads to delays in the release of organs and can result in wastage. We aim to assess whether a signal/cut‐off (S/CO) ratio higher than the manufacturer's recommendation of 1.0 in the Abbott Architect antibody assay is a reliable measure of HTLV‐1/2 infection.MethodsWe conducted a 5 year retrospective analysis of 7245 patients from which 11 766 samples were tested on the Abbott Architect rHTLV I/II assay. Reactive samples (S/CO >1) were referred for confirmatory serological and molecular detection (Western Blot and proviral DNA) at UK Health Security Agency, (formerly PHE, Colindale), the national reference laboratory. Electronic, protected laboratory and hospital patient databases were employed to collate data.ResultsA total of 45 patients had initially reactive samples. 42.2% (n = 19/45) had an S/CO ratio > 20, with HTLV infection confirmed in n = 18/19 and indeterminate confirmatory results in n = 1/19. No samples with an S/CO ratio <4 (48.9%, n = 22/45) or 4–20 (8.9%, n = 4/45) had positive confirmatory results on subsequent confirmatory testing.ConclusionSamples with an S/CO >20 likely represent a true HTLV‐1/2 infection. Reactive samples with an S/CO <4 were unlikely to confirm for HTLV infections. Interpretation of these ratios can assist clinicians in the assessment of low reactive samples and reiterates the need for faster access to confirmatory testing.

Thyroid Cancer Detection in a Routine Clinical Setting: Performance of ACR TI-RADS, FNAC, and Molecular Testing in Prospective Cohort Study.

The aim of our study was to address the potential for improvements in thyroid cancer detection in routine clinical settings using a clinical examination, the American College of Radiology Thyroid Imaging Reporting and Database System (ACR TI-RADS), and fine-needle aspiration cytology (FNAC) concurrently with molecular diagnostics. A prospective cohort study was performed on 178 patients. DNA from FNA samples was used for next-generation sequencing to identify mutations in the genes BRAF, HRAS, KRAS, NRAS, and TERT. RNA was used for real-time PCR to detect fusion genes. The strongest relevant positive predictors for malignancy were the presence of genetic mutations (p < 0.01), followed by FNAC (p < 0.01) and ACR TI-RADS (p < 0.01). Overall, FNAC, ACR TI-RADS, and genetic testing reached a sensitivity of up to 96.1% and a specificity of 88.3%, with a diagnostic odds ratio (DOR) of 183.6. Sensitivity, specificity, and DOR decreased to 75.0%, 88.9%, and 24.0, respectively, for indeterminate (Bethesda III, IV) FNAC results. FNA molecular testing has substantial potential for thyroid malignancy detection and could lead to improvements in our approaches to patients. However, clinical examination, ACR TI-RADS, and FNAC remained relevant factors.

Autoimmune markers in screening for orbital inflammatory disease

PurposeImmunogenic causes of inflammation may be difficult to differentiate in the work-up of orbital inflammatory disease. The study aims to investigate the utility of autoimmune markers in the screening for orbital inflammation. Markers studied included angiotensin-converting enzyme (ACE), antinuclear antibody (ANA), anti-neutrophilic cytoplasmic autoantibodies (ANCA), extractable nuclear antigen (ENA), anti-cyclic citrullinated peptide (Anti-CCP) and anti-double stranded DNA antibody (Anti-dsDNA antibody).MethodsA retrospective single-centre study of consecutive patients with non-infective orbital inflammation screened for autoimmune markers at presentation. Serology was interpreted alongside clinical course and other investigations (e.g. radiographic features and histopathology). Tabulated data and Pearson’s Chi-square allowed analysis of trends between serology, diagnosis and the decision to biopsy.Results79 patients, between 1999 and 2021, were included (50 females, mean age was 50.4 ± 17.4 years). 28 (34.6%) patients had specific orbital inflammation and 53 (65.4%) patients had non-specific orbital inflammation (NSOI). Of the 12 patients with positive serology and a specific diagnosis, only 5 (41.7%) patients had concordant serological results. There was no association between serology results and the patient undergoing biopsy (P = 0.651). Serology was unable to exclude nor differentiate NSOI from other specific conditions and ANA had limited discriminatory value between specific conditions and NSOI.ConclusionSerological testing alone may not provide a clear direction for further investigation of orbital inflammation and a biopsy may occur independently of the serological results. The value of autoimmune markers may lie in subsequent follow-up as patients may develop suggestive symptoms after an indeterminate positive result or initially seronegative disease.

Comparative Evaluation of GeneXpert MTB/RIF Ultra and GeneXpert MTB/RIF for Detecting Tuberculosis and Identifying Rifampicin Resistance in Pars Plana Vitrectomy Samples of Patients with Ocular Tuberculosis

ABSTRACT Background Xpert MTB/RIF Ultra (Ultra) was evaluated for the first time on Ocular tuberculosis (OTB) samples and compared with Xpert. Methods Seventy five vitreous fluid samples (3 confirmed OTB, 47 clinically suspected OTB, and 25 controls) were subjected to Ultra, Xpert and Multiplex-PCR and compared against culture, composite reference standard (CRS), and gene sequencing. Results The sensitivity of Ultra was 50% in diagnosing OTB (100% against culture and 46.8% against CRS). The overall sensitivity of Xpert and MPCR was 16% and 72%, respectively. Xpert missed three culture-positive cases and MPCR detected additional 11. Ultra and Xpert missed two and four cases of RifR, respectively. A total of 13(59%) cases were reported ‘trace’ by Ultra in which RifR could not be evaluated. Conclusion Ultra outperformed Xpert in diagnosing OTB. The advantage of Ultra’s simultaneous RifR detection is lost since the trace bacterial loads in the specimens cause indeterminate results of RifR testing. Abbreviations: OTB: Ocular tuberculosis; Ultra: Xpert MTB/RIF Ultra; Xpert: Xpert MTB/RIF, MPCR: multiplex polymerase chain reaction; NAATs: Nucleic acid amplification tests; MLAMP: multitargeted loop-mediated isothermal amplification; PPV: positive predictive value; NPV: negative predictive value; EPTB: extrapulmonary tuberculosis; VF: vitreous fluid; DNA: deoxyribonucleic acid; ATT: antitubercular therapy; RifR: Rifampicin resistance; RifS: Rifampicin susceptible; RifI: Rifampicin indeterminate.

Fast detection and quantification of Plasmodium species infected erythrocytes in a non-endemic region by using the Sysmex XN-31 analyzer

BackgroundDue to increased travel from endemic countries, malaria occurs more frequently in non-endemic regions. It is a challenge for diagnostic laboratories in non-endemic countries to provide reliable results, as experience of staff is often limited to only a few cases per year. This study evaluated the diagnostic accuracy of the fully automated Sysmex XN-31 malaria analyzer in a routine diagnostic setting in a non-endemic region was evaluated.MethodsSamples from 112 patients suspected for malaria were examined by the Sysmex XN-31 analyzer to determine the absolute count of malaria-infected red blood cells count (MI-RBC/µL). Microscopic examination of both Quantitative Buffy Coat capillary tubes and thick and thin blood films were used as reference methods. Limits of blank (LoB), detection (LoD) and quantification (LoQ) were investigated using an in vitro Plasmodium falciparum culture. Nine hundred twenty samples of patients with RBC abnormalities were included to determine which RBC abnormalities trigger indeterminate or false positive results.ResultsNo false positive nor false negative results were obtained for the examined patient samples suspected for malaria. For 3% of samples an indeterminate result by the XN-31 was obtained. The Passing-Bablok regression line for diagnostic accuracy of the parasitaemia was y = 39.75 + 0.7892 × showing a positive bias of about 21% when comparing the MI-RBC results to microscopy. The LoB, LoD and LoQ were calculated to be 4.7, 5.9, and 19.0 infected RBC/μL, respectively. From the 920 abnormal RBC samples collected, 4.6% resulted in a false positive MI-RBC result and almost half of the samples produced indeterminate results. These results were related to increases in nucleated red blood cells, reticulocytes and other abnormal RBC morphologies such as sickle cells.ConclusionsBased on the results, the XN-31 is a fast and reliable screening method in the detection and quantification of Plasmodium species in patients However, if an abnormal red blood cell morphology is present, the results of the XN-31 should be interpreted with caution as false positive results can be caused by interfering abnormal erythrocytes.

Diagnostic accuracy of imaging approaches for early tumor detection in children with Li-Fraumeni syndrome.

The Toronto protocol for cancer surveillance in children with Li-Fraumeni syndrome has been adopted worldwide. To assess the diagnostic accuracy of the imaging used in this protocol. We conducted a blinded retrospective review of imaging modalities in 31 pediatric patients. We compared imaging findings with the reference standards, which consisted of (1) histopathological diagnosis, (2) corresponding dedicated imaging or subsequent surveillance imaging or (3) clinical outcomes. We individually analyzed each modality's diagnostic performance for cancer detection and assessed it on a per-study basis for chest and abdominal regional whole-body MRI (n=115 each), brain MRI (n=101) and abdominal/pelvic US (n=292), and on a per-lesion basis for skeleton/soft tissues on whole-body MRI (n=140). Of 763 studies/lesions, approximately 80% had reference standards that identified 4 (0.7%) true-positive, 523 (85.3%) true-negative, 5 (0.8%) false-positive, 3 (0.5%) false-negative and 78 (12.7%) indeterminate results. There were 3 true-positives on whole-body MRI and 1 true-positive on brain MRI as well as 3 false-negatives on whole-body MRI. Sensitivities and specificities of tumor diagnosis using a worst-case scenario analysis were, respectively, 40.0% (95% confidence interval [CI]: 7.3%, 83.0%) and 38.2% (95% CI: 29.2%, 48.0%) for skeleton/soft tissues on whole-body MRI; sensitivity non-available and 97.8% (95% CI: 91.4%, 99.6%) for chest regional whole-body MRI; 100.0% (95% CI: 5.5%, 100.0%) and 96.8% (95% CI: 90.2%, 99.2%) for abdominal regional whole-body MRI; sensitivity non-available and 98.3% (95% CI: 95.3, 99.4) for abdominal/pelvic US; and 50.0% (95% CI: 2.7%, 97.3%) and 93.8% (95% CI: 85.6%, 97.7%) for brain MRI. Considerations for optimizing imaging protocol, defining criteria for abnormalities, developing a structured reporting system, and practicing consensus double-reading may enhance the diagnostic accuracy for tumor surveillance.