Clinical chemistry and laboratory medicine最新文献

Objectives: Early rheumatoid arthritis (RA) detection is crucial for improving patient prognosis. Anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factors (RF) support RA diagnosis but are undetectable in ∼20 % of cases. Recently, antibodies against mutated citrullinated vimentin (anti-MCV) and detection of 14-3-3 eta have emerged with implications for preclinical RA diagnosis and monitoring treatment. The objective of this study was to assess the clinical performance of anti-MCV antibodies and 14-3-3 eta in RA and to compare it to current RA criteria anti-CCP and RF markers, individually and in combination.

Methods: A retrospective chart review of 326 subjects submitted for RA serology testing identified 134 RA positive and 192 RA negative disease control individuals. Fifty healthy controls specimens were also included. Performance of anti-MCV and 14-3-3 eta, alone and combined with CCP3.1 and RF, was assessed.

Results: Anti-MCV had a sensitivity of 71 % and a specificity of 92 %. 14-3-3 eta had a sensitivity of 43 % and a specificity of 90 %. In comparison, CCP3.1 and RF displayed a sensitivity of 79 % and 84 % and a specificity of 92 % and 61 %, respectively. ROC curve analysis demonstrated CCP3.1 and anti-MCV had superior diagnostic performance compared to RF and 14-3-3 eta. In our cohort, anti-MCV and 14-3-3 eta failed to identify seronegative RA patients. Different combinations of double antibody positivity increased specificity at the cost of lost sensitivity.

Conclusions: Individually, 14-3-3 eta, anti-MCV and CCP3.1 assays had ≥90 % specificity in diagnosed RA patients, with better sensitivities for anti-MCV and CCP3.1 than 14-3-3 eta. Overall diagnostic performance of anti-MCV was similar to CCP3.1 and RF, all of which outperformed 14-3-3 eta in our cohort.

Objectives: As high-sensitivity cardiac troponin T (hs-cTnT) is making the transition from diagnostic to prognostic use, a long-term stability study of 5th generation hs-cTnT according to EFLM CRESS recommendations was set up for investigation of frozen clinical specimens (two matrices).

Methods: Study samples collected in serum tubes and lithium heparin tubes with gel from patients admitted for suspected minor myocardial damage were measured directly after completion of the study (0 years), and after 3-year and 6-year storage at -80 °C, and recovery of hs-cTnT concentrations after long-term storage (%hs-cTnT concentration compared to 0-year) was calculated. Hs-cTnT changes were also compared to decisive delta changes, such as the ones proposed in the ESC NSTEMI 0 h/1 h algorithm (<3 or >5 ng/L for ruling out and ruling in suspected NSTEMI patients).

Results: Eighty-six patients were included in the study, whereof 28 both lithium heparin plasma and serum samples were collected simultaneously, in others only serum (n=30) or plasma (n=28). Multiple aliquots per patient were made, so that 479 serum and 473 plasma samples were available for analysis. Across the overall hs-cTnT measuring range, median recovery after 6 years was 105.4 % and 106.2 % for serum and plasma, respectively. Based on these decisive delta changes, serum showed consistent results upon long term storage (max 0.8 % of samples above delta threshold of >5 ng/L) as compared to heparin plasma (up to 19.2 % of samples above threshold).

Conclusions: Over 6 years of storage at -80 °C, recovery of hs-cTnT in serum and heparin plasma was similar and within common lot-to-lot variation. Yet, when evaluating absolute delta increments around hs-cTnT clinical decision points, long-term stored sera displayed better clinical performance compared to heparin plasma samples.

Objectives: Subarachnoid haemorrhage (SAH) has a high morbidity and mortality and requires prompt diagnosis. In patients with negative findings on computed-tomogram of the brain (CT-Brain) cerebrospinal fluid (CSF)-xanthochromia is considered the test of choice if performed 12 h or more after symptom onset. We audited the accuracy, usefulness and timing of CSF-xanthochromia testing and the interpretation of equivocal CSF-xanthochromia findings. We also investigated mortality outcomes for defined subsets of patients.

Methods: A retrospective audit of CSF-xanthochromia tests over 8 years was performed. The service uses the revised UK-NEQAS (United Kingdom National External Quality Assessment Service) method.

Results: We analysed 543 cases (F=299, median age 44yrs) with 19 cases (3.5 %) having SAH. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CSF-xanthochromia testing were 100 , 98.1, 65.9, 100 % respectively (equivocal results were counted as positives). 280 cases (F=153, median age 43yrs) had LP performed more than 24 h after the onset of headache (median time to LP=72 h). The sensitivity and specificity of the CSF-xanthochromia were 100 and 97.4 % in this group with NPV 100 % and PPV 66.6 %. 183 (65.4 %) CSF- xanthochromia negative cases in this subgroup had follow up data and survived without SAH occurring in the 12 months follow up.

Conclusions: In this study, supported by follow up outcome data, we show that CSF-xanthochromia testing using the revised UK-NEQAS method is fit-for-purpose for the use as a second line test to exclude SAH in patients with negative CT-brain including delayed presentation more than 24 h after headache onset.

Objectives: Quantitative protein mass spectrometry (MS) is ideally suited for precision diagnostics and for reference standardization of protein analytes. At the Leiden Apolipoprotein Reference Laboratory we apply MS strategies to obtain detailed insight into the protein-to-peptide conversion in order to verify that quantifier peptides are not partly concealed in miscleaved protein backbone.

Methods: Apolipoprotein(a) (apo(a)) was digested in a non-optimal manner to enhance the number of miscleaved peptides that were identified by high resolution liquid chromatography tandem-MS measurements. The protein-to-peptide conversion was carefully mapped with specific attention for miscleaved peptides that contain an apo(a) quantifier peptide. Four different isotopologues of each apo(a)-quantifier peptide were applied to evaluate linearity of internal peptide standards during measurement of specific real-life samples.

Results: Two apo(a) quantifier peptides that were concealed in two different miscleaved peptides were included into a multiple reaction monitoring list in our targeted MS-based apo(a) quantifications to alert for potential protein digestion discrepancies. The presence of miscleaved peptides could be ruled out when applying our candidate reference measurement procedure (RMP) for apo(a) quantification.

Conclusions: These data further corroborate the validity of our apo(a) candidate RMP as higher order method for certification of commercial Lp(a) tests that is endorsed by the International Federation of Clinical Chemistry and Laboratory Medicine. MS-based molecular detection and quantification of heterogeneous apo(a) proteoforms will allow manufacturers' transitioning from confounded lipoprotein(a) [Lp(a)] mass levels into accurate molar apo(a) levels.

Background: As the healthcare sector evolves, Artificial Intelligence's (AI's) potential to enhance laboratory medicine is increasingly recognized. However, the adoption rates and attitudes towards AI across European laboratories have not been comprehensively analyzed. This study aims to fill this gap by surveying European laboratory professionals to assess their current use of AI, the digital infrastructure available, and their attitudes towards future implementations.

Methods: We conducted a methodical survey during October 2023, distributed via EFLM mailing lists. The survey explored six key areas: general characteristics, digital equipment, access to health data, data management, AI advancements, and personal perspectives. We analyzed responses to quantify AI integration and identify barriers to its adoption.

Results: From 426 initial responses, 195 were considered after excluding incomplete and non-European entries. The findings revealed limited AI engagement, with significant gaps in necessary digital infrastructure and training. Only 25.6 % of laboratories reported ongoing AI projects. Major barriers included inadequate digital tools, restricted access to comprehensive data, and a lack of AI-related skills among personnel. Notably, a substantial interest in AI training was expressed, indicating a demand for educational initiatives.

Conclusions: Despite the recognized potential of AI to revolutionize laboratory medicine by enhancing diagnostic accuracy and efficiency, European laboratories face substantial challenges. This survey highlights a critical need for strategic investments in educational programs and infrastructure improvements to support AI integration in laboratory medicine across Europe. Future efforts should focus on enhancing data accessibility, upgrading technological tools, and expanding AI training and literacy among professionals. In response, our working group plans to develop and make available online training materials to meet this growing educational demand.

Objectives: Congenital adrenal hyperplasia (CAH) is a rare, inherited disorder of adrenal steroid synthesis. In many countries it is part of the neonatal screening program enabling early diagnosis and treatment. In case of an abnormal neonatal screening result or when other differences of sexual development (DSD) are suspected, measurement of serum steroid hormones using liquid chromatography coupled to mass spectrometry (LC-MS/MS) is needed for further diagnosis. However, reliable age- and sex-specific reference intervals (RIs) for serum steroid hormones during the neonatal period are missing. We therefore aimed to establish LC-MS/MS based RIs for serum steroid hormones in neonates.

Methods: Serum was obtained from healthy term neonates at two time points: 130 samples at day 3-8 (T1, time of the neonatal screening) and 126 samples at day 13-15 (T2, two weeks old). Concentrations of cortisol, cortisone, corticosterone, 11-deoxycortisol, 21-deoxycortisol, 11-deoxycorticosterone, testosterone, androstenedione, and 17-hydroxyprogesterone (17-OHP) were measured using LC-MS/MS.

Results: RIs (in nmol/L) were established for T1 and T2: cortisone (19.3-215;18.0-212), cortisol (10.0-407;8.4-446), corticosterone (<31;<50), 11-deoxycortisol (0.73-4.6;0.70-3.6), 17-OHP (<4.9;<5.1), androstenedione (0.3-1.8;0.3-2.7), 11-deoxycorticosterone (<0.2;<0.2), and 21-deoxycortisol (<1;<1), respectively. Testosterone differed between boys and girls: RIs at T1 and T2 for boys were 0.27-4.3 and 0.63-13.9, and for girls<0.30 and <0.47, respectively.

Conclusions: We established LC-MS/MS based RIs for cortisol, cortisone, corticosterone, 11-deoxycortisol, 21-deoxycortisol, 11-deoxycorticosterone, testosterone, androstenedione, and 17-OHP in neonates in the first and second week of life.

Objectives: The development of External Quality Assessment Schemes (EQAS) for clinical flow cytometry (FCM) is challenging in the context of rare (immunological) diseases. Here, we introduce a novel EQAS monitoring the primary immunodeficiency Orientation Tube (PIDOT), developed by EuroFlow, in both a 'wet' and 'dry' format. This EQAS provides feedback on the quality of individual laboratories (i.e., accuracy, reproducibility and result interpretation), while eliminating the need for sample distribution.

Methods: In the wet format, marker staining intensities (MedFIs) within landmark cell populations in PIDOT analysis performed on locally collected healthy control (HC) samples, were compared to EQAS targets. In the dry format, participants analyzed centrally distributed PIDOT flow cytometry data (n=10).

Results: We report the results of six EQAS rounds across 20 laboratories in 11 countries. The wet format (212 HC samples) demonstrated consistent technical performance among laboratories (median %rCV on MedFIs=34.5 %; average failure rate 17.3 %) and showed improvement upon repeated participation. The dry format demonstrated effective proficiency of participants in cell count enumeration (range %rCVs 3.1-7.1 % for the major lymphoid subsets), and in identifying lymphoid abnormalities (79.3 % alignment with reference).

Conclusions: The PIDOT-EQAS allows laboratories, adhering to the standardized EuroFlow approach, to monitor interlaboratory variations without the need for sample distribution, and provides them educational support to recognize rare clinically relevant immunophenotypic patterns of primary immunodeficiencies (PID). This EQAS contributes to quality improvement of PID diagnostics and can serve as an example for future flow cytometry EQAS in the context of rare diseases.