Current recommendations for screening Chlamydia trachomatis (CT) and Neisseria gonorrhoeae in urinary tract infections using nucleic acid amplification tests (NAATs) include vaginal swabs for women and first‑catch urine for men. In addition, some manufacturers require the use of a transport medium for prolonged pre‑analytical storage. The aim of this study was to evaluate the sensitivity and specificity of midstream urine specimens and to assess nucleic acid stability in neat urine samples stored at +4°C. The study included 338 asymptomatic participants undergoing screening for Chlamydia trachomatis and Neisseria gonorrhoeae as part of the French national STI screening program (172 women and 166 men). For each participant, a reference specimen (self‑collected vaginal swab for women and first‑catch urine for men) was compared with a midstream urine sample. Two comparisons were conducted to assess nucleic acid stability: the first compared urine stored in a preservation medium with neat urine stored at +4°C, and the second compared neat urine stored at +4°C on days 1 and 7. All samples were analysed using the Alinity m Abbott® automated system with the STI AMP Kit. Among the 46 positive samples, the prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was 43/338 and 4/338, respectively. Due to the low prevalence of NG, sensitivity and specificity analyses for midstream urine were limited to CT. Vaginal swabs showed superior performance for detecting CT in females, with two infections missed by midstream urine. Midstream urine demonstrated adequate sensitivity in females (92.9%) and excellent sensitivity in males (100%), with no false-positive results observed. Regarding nucleic acid stability, no statistical difference (p=0.799) was observed for cycle values between urine samples eluted into the liquid medium and neat urine stored at +4°C. Furthermore, our study validated the use of prolonged storage periods (up to 7 days) at +4°C for CT and NG detection in neat urine (p=0.671). In conclusion, the results of this study corroborate the CDC's 2014 recommendations, but the use of midstream urine could offer interesting prospects for Chlamydia trachomatis screening in specific populations. Regarding Neisseria gonorrhoeae, given the low prevalence of positive results found in our study, no meaningful conclusions can be drawn.

Background:Analytical performance specifications (APSs) are essential for quality management in medical laboratories. Considering the discrepancies between laboratory performance and existing guidelines, lack of consideration of concentration-dependent variability, and absence of recommendations for certain parameters, we aimed to define APSs for internal use in biochemistry, hemostasis, and hematology based on external quality assessment (EQA) peer group data and evaluate their suitability for intermediate precision assessment versus biological variation (BV)-based APSs. Methods:EQA-based allowable CV (CVallowable) was estimated from pooled CVs derived from EQA peer group results. Allowable bias, expanded measurement uncertainty, and total allowable error were calculated. CVallowable targets were assessed using intermediate precision data from different analytical systems within a laboratory group and compared with BV-based APSs. Concordance between theoretical specifications derived from mathematical models and observed analytical performance (AP) was evaluated using (i) the proportion of internal QC CVs meeting the predefined CVallowable across laboratories and (ii) observed analytical imprecision expressed as a percentage of the allowable imprecision budget. Results:APSs were established for 110 biochemical analytes, 23 hemostasis parameters, and 28 hematology parameters across different concentration ranges. EQA-derived APSs agreed with observed intermediate precision for 102 biochemical, 14 hemostasis, and 24 hematology parameters. BV-based APSs showed agreement for only 49 biochemical, two hemostasis, and 11 hematology parameters, while overly restrictive goals or lack of agreement were observed for several analytes. Conclusions:APSs derived from pooled EQA peer group data provide realistic and technically achievable intermediate precision targets consistent with current AP and thus can complement BV-based specifications.

Objectives: Following the release of an informational bulletin, Roche Diagnostics adopted a more restrictive hemolysis index (100 HI) for the release of serum lipase results on all Cobas systems. This study aimed to evaluate the interference threshold for serum lipase hemolysis on Cobas C501/311/701/Integra 400 systems using a total allowable error set by Methods: To assess the influence of hemolysis on lipase, the parameter was quantified in serum pools spiked with escalating concentrations of a hemolysis interferent. The lipase assay was performed using the colorimetric lipase method (LIPC), and the HI was determined by absorbance measurements of diluted samples in accordance with the system protocol. Results: The Cobas Integra 400 and Cobas C311 showed the greatest interference of lipase with hemolysis (<= 300 HI). The Cobas C501 and C701 demonstrated less sensitivity to hemolysis (<= 1300 HI). Conclusion: The results of this study demonstrate that interference limits may vary between different Roche systems, even when the same reagent is used. Our study indicated that the lipase hemolysis threshold (100 HI) currently set by the manufacturer was excessively restrictive. This finding highlights the necessity of verifying manufacturers' information bulletins to provide better medical care.

Objectives: Considering the recommendations of literature, it was important to note the potential for differences in pre-and post-analytical storage conditions at room temperature between total and free prostate-specific antigen. The aim of our study was to establish whether it would be appropriate to align the pre-and post-analytical times for the determination of free prostate-specific antigen (fPSA) with those for total prostate-specific antigen (tPSA). Methods: Two blood samples were taken from 48 male patients aged 60 to 84. One specimen was centrifuged within one hour of collection. Each sample was tested immediately for total and free PSA. The second blood sample was kept at room temperature for 12 hours before being tested and then reanalyzed 24 hours after blood sampling. Serum specimens were analyzed on the Roche Cobas E801. Results: There were no notable alterations in any PSA forms (p=0.866 and 0.971) or calculated ratios (Kappa=1) for the blood sample that was stored at room temperature for 12 hours prior to processing. Furthermore, all forms of PSA demonstrated stability (p=0.956 and 0.901), and fPSA/tPSA ratios showed good agreement in serum for up to 24 hours at room temperature (Kappa=1). Conclusion: It would be beneficial to extend the pre-and post-analysis times of fPSA to align them with those of tPSA. Following the elevated tPSA discovery, investigating fPSA could be more streamlined, offering an improved patient management solution.

In the presence of haemolysis, the interpretation of the Lactate dehydrogenase (LDH) activity result is a major operational challenge for medical laboratories: if the origin is intravascular, then the measurement will reflect the clinical reality, but in extravascular haemolysis, the laboratory will be confronted with an artefactual increase leading to false-positive high results. The aim of our study was to evaluate the adjustment of LDH concentration results according to the haemolysis index (HI). After designed a mathematical model to correct the LDH measured as a function of the haemolysis index using a Cobas 8000 analyser (Roche diagnostics, Mannheim, Germany), LDH measurement of seventy-four duplicate samples were tested before and after exposure to extravascular haemolysis process. After in vitro haemolysis process, a significant increase haemolysis index (Man-Whitney U-Test p < 0.0001) were observed. Before process the HI median was 4 [2.0 - 6.75] and after HI median was 18 [10 - 35.75]. Without correction, LDH results showed a significant increase (p < 0.001) after haemolysis process and substantial analytical discrepancies (31/74) were observed according to TEa of CLIA. After correction, data showed no significant difference (p = 0.497) and the mathematical algorithm allowed to reduce the analytical discrepancies (2/74). If haemolysis was present in vitro, the mathematical algorithm increased the accuracy of the LDH results. However, the lack of discrimination between in vivo and in vitro haemolysis requires caution and the results should be reported only as a commentary to inform the clinician.

Introduction: Verification and validation of analytical methods are crucial aspects of quality assurance in a laboratory. This study aimed to develop a risk analysis and assessment tool to streamline the process of identifying so-called 'sentinel' tests. Materials and methods: The Roche Cobas 8000 systems were evaluated to analyze 83 serum analytes, including routine chemistry, immunoassays, and therapeutic drugs. A failure mode and effects analysis were conducted to produce an analytic risk rating. This was achieved by multiplying the scores for Sigma metrics, the score for potential damage extent, and the score for environmental factors. Each test was assigned a typical risk priority number (RPN). Tests with an RPN of <= 9 were rated as low risk and ranked as 'B'. Tests with an RPN of >10 were considered high risk and graded as 'A'. Results: Regarding the Cobas C701/ISE, 17 of 54 methods were rated as 'A' and subject to a systematic method review process. A total of 37 methods were assigned a rank of 'B' and hence were eligible for a selective verification process. Concerning the Cobas E801, 10 out of 29 methods were classified as 'A' and, therefore, require a systematic verification process. A further nineteen methods were assigned a rank of 'B' and hence eligible for a select verification. Conclusions: This study demonstrated the high effectiveness of the risk analysis and assessment model developed to identify sentinel tests in the lean management of the verification/validation process.

The objective of this study was to compare the results of semen analysis using the manual method and the SQA-Vision sperm analyser after four years of practice and with a large cohort of patients. This was a comparative study of 1130 cases collected for semen analysis between October 2019 and October 2023, which were analysed simultaneously and independently by different operators using the manual microscopic method and an SQA-V automated analyser. For each sample, sperm concentration, progressive motility, motility, normal morphology, and round cells count were performed. There was no significant difference between the SQA-V method and manual assessment for all sperm parameters (Mann-Whitney test p > 0.05). According to the parameter studied, there was a strong correlation (rho = 0.81) and a very high correlation (rho = 0.98) between manual assessment and the SQA-V method. In the analysis of sperm concentration, the sensitivity and specificity were 0.90 and 0.99, respectively. The sensitivity and specificity for the analysis of sperm progressive motility were 0.98 and 0.99, respectively, while the sensitivity and specificity for the analysis of sperm motility were 0.87 and 0.99, respectively. The sensitivity and specificity for the analysis of normal morphology were 0.88 and 0.99, respectively. Regarding the analysis of round cells, the sensitivity and specificity were 0.98 and 0.99, respectively. The results of this retrospective study indicate that the SQA-V system offers satisfactory performance for routine sperm analysis.

Objectives: The Di@pason scheme, introducing a point-of-care (POC) International Normalized Ratio (INR) measurement with the LabPad (R) was initiated in 2019 by the French National Health Agency. The aim of our study was to assess the analytical agreement between LabPad (R) and laboratory INR results, especially at sub- and supratherapeutic levels. The allowable differences were based on the accuracy requirement defined by the International Standard ISO 17593:2022 and analytical discordances versus INR Ranges. Methods: From February 2020 to August 2022, the agreement between POC and laboratory INR results was analyzed in 83 patients. All subjects were monitored on oral anticoagulant therapy (57 patients treated with fluindione (Previscan (R)), 24 patients were treated with warfarin (Coumadin (R)) anticoagulant medication and acenocoumarol (Sintrom (R)) was used for two subjects). Results: The laboratory INR results ranged from 1.2 to 10 with a mean of 3.736 +/- 1.479, and LabPad (R) INR ranged from 0.8 to 7.3 with a mean of 3.818 +/- 1.599. Analysis of the graph demonstrated that the INR relationship between LabPad (R) and STA-R Max3 (R) did not remain linear above 7.3. An extended measurement area and Pearson correlation coefficient (r) showed a significant and strong (r=0.91 [p<0.001; 95% CI: 0.81-1.00]). The regression slope was 0.980 (p<0.001; 95% CI: 0.878-1.081) and the y intercept was 0.158 (p<0.001; 95% CI: -0.251-0.566). The concordance analysis showed that 93% of the results were within the accuracy requirement defined by the international standard ISO17593:2022, but significant discrepancies appeared on the LabPad (R) for INR results above 4. According to analytical discrepancies and INR, ranges showed substantial agreement on these criteria with 88% and a Kappa coefficient of 0.67. Conclusion: The LabPad (R) and laboratory INR results were highly correlated within the therapeutic range, above this range, a venous checking is recommended to confirm the results.

Reference intervals (RIs) for prolactin are of high clinical importance for diagnosis, treatment, and prognosis of hypothalamic-pituitary disorders. The aim of this study was to verify the Roche reference ranges for serum prolactin in children, adolescents, adults, and the elderly. : An indirect method based on currently laboratory data was used on the reference ranges. Nine thousand one hundred and thirteen prolactin results were included. Pregnancy, lactation, exercise and reported pathologies were ruled out and only samples were collected between 8AM and 12PM were used. Reference ranges with a confidence interval of 95% (95% CI) were estimated. : Compared to the manufacturer's reference values and for the corresponding age group, the median values obtained in our study were 10 – 60% higher depending on the age and sex of the patients. Elevated levels of serum prolactin were observed in the neonatal period and values decrease until median values near 200 mUI/L in childhood. During the children's period, no gender differences were observed for prolactin level. The gender difference in prolactin levels became significant from pre-adolescence until the age of 60. Prolactin levels increased significantly (p<0.001) between children and young adults, followed by a gradual and continuous decrease until young senior age. : The prolactin reference values proposed by the manufacturer in the data sheet appeared unsuitable. Laboratories should review reference ranges, and a partitioning with sex and different age groups may be appropriate.

The Beckman Coulter® DXH900 uses the impedance method to measure the total leukocytes count. In presence of platelet aggregates, the device identifies the structural changes and associates an alarm with the leukocytes result. The aim of this study was to evaluate the influence of platelet aggregates using the principle of flow cytometry as a second assessment of the white blood cell count. Total leukocytes count was evaluated in 49 specimens with presence of platelet aggregates and 32 without anomaly. The differences between total leukocyte count by the two automatic methods (impedance and flow cytometry) and the microscopic method were compared. Without platelet aggregates, the median values were 5.6 (microscopic cell count), 5.4 (impedance) and 5.4 (flow cytometry) and no discordance was observed. In presence of platelet aggregates, the median values were 5.6, 6.4 and 5.1 respectively. The graphical analysis with the allowable total error range of ± 25.7% showed substantial analytical discrepancies (15/49) using impedance method while the flow cytometry method revealed minor disagreements (3/49). Analytical discordances versus WBC reference ranges showed 88% agreement and a substantial Kappa coefficient of 0.70 by impedance, while the flow cytometry method had 94% agreement and a perfect Kappa coefficient of 0.83. The formation of platelet aggregates increased the total leukocyte count performed DXH900 impedance method. Our study has shown that DXH 900 flow cytometry method may be an alternative to exclude the presence of pseudoleukocytosis. In case flags are generated, the microscopic method may be needed for the confirmation of WBC count.

INTRODUCTION: In the context of the accreditation of medical laboratories according to the ISO 15189: 2012 standard, the optimisation of an internal quality control (IQC) schedule is an important element of analytical quality. The study focuses on an essential test for the follow-up of diabetic patients: Haemoglobin A1c (HbA1c). METHODS: The analysis was performed on three TERA® Capillarys (Sebia®) analyzers. Data were collected for 1 month calculating imprecision and analytical bias. A total error allowable (TEa) of 6% was used to calculate the Sigma metrics. A statistical quality control (SQC) procedure based on the Sigma metrics of the analytical procedure, the selected rules and numbers of control measurements were applied to determine the optimised run size and to guarantee the required quality of patient care. RESULTS: With a mean of 5-Sigma. 'Normalised Chart' showed a good/excellent performance for the HbA1c method. The SQC run size nomogram indicated a desirable event size of around 53 samples/capillary (for n=1 and 13s) and 170 samples/capillary (for n=2 and 13s). DISCUSSION AND CONCLUSION: Our study demonstrated the usefulness of the sigma metric SQC run size nomogram to determine the control strategy for HBA1c and contributes to the quality of results rendered to patients.

"Response to the comments of Mukerji and Jones." Scandinavian Journal of Clinical and Laboratory Investigation, 81(6), p. 424

Roche Diagnostics (R) decided a more restrictive haemolysis index (<= 20 HI) for approval the release of serum potassium results. This study examined the risk of overestimating serum potassium results related to the HI according to the Ricos total error (+/- 5.6%) and evaluated the approach of Martinez-Morillo and Alvarez to determine a corrected potassium. According to Ricos' criteria, our study showed compliant potassium results with HI less than or equal to 75. Between 90 and 100 HI, the results did not show a significant overestimation. The equation to obtain K-corrected was: K-measured - (0.004 x HI). The use of corrective formulas for adjusting results of potassium could help the laboratory to identify patients at increased risk and to repeat the test as soon as possible.

Impact of the presence of debris on semen analysis using an automated system (SQA-V)Objectives: This study examined the influence of the manual assessment of debris on the results of sperm concentration, progressive motility, and normal morphology measured using the SQA-V system (Medical Electronic Systems LLC, Los Angeles, CA, USA).Methods: Sixty samples were analyzed simultaneously and independently by different operators using the manual technique and the SQA-V analyzer.Three measurements (sperm concentration, progressive motility, and normal morphology) of each sample were assessed using the 4 debris assessment levels: none/few, moderate, many, and gross.Results: Given an optimal assessment of debris, the study data indicate that the SQA-V provided results that had very good agreement with those of the manual method: sperm concentration (rho=0.987,regression analysis formula: y=0.961x+1.962,p<0.0001), progressive motility (rho=0.949,regression analysis formula: y=0.989x+0.418,p<0.0001), and normal morphology (rho=0.694,regression analysis formula: y=0.678x+4.061,p<0.0001).Underestimation of debris increased sperm concentration and decreased motility and normal morphology, while overestimation of debris decreased sperm concentration and increased motility and normal morphology. Conclusion:The results indicated that the performance of the SQA-V remains subject to the competency of the operator.

This study examined the influence of temperature and time on the pre-analytical stability of the erythrocyte sedimentation rate (ESR) measured on a TEST1 system. The first experiment included 102 samples stored at room temperature and the second experiment included 112 subjects and investigated refrigerated (2-8 degrees C) storage. Our study showed a stable ESR results at room temperature (15-25 degrees C) up to 8 h (p = 0.512). Samples stored at 2-8 degrees C for 24 h were stable (p = 0.280) for 24 h.

In the context of point of care testing (PoCT) and ISO 22870, internal quality control (IQC) is a crucial part of PoCT accreditation processes. Quality Control materials shall be periodically examined with a frequency that is based on the robustness of the analytical procedure and the risk of harm to the patient from an erroneous result. We propose to apply the statistical quality control (SQC) procedure to develop an individualized QC plan for AQT90 flex instrument used in PoCT. The robustness is determined by the sigma-metric and analytical goal represented by an allowable total error (TEa) is evaluated using a Varela graphic tool. A Sigma-metric SQC run size nomogram for estimating the number of patient samples between IQC events. According to the calculated robustness we can distinguish 3 groups of parameters: HCG and CRP with large sample size per event, D-Dimer and Procalcitonin with an average sample size per event and Myoglobin. NT-proBNP. and Troponin T with a limited sample size per event. In PoCT, the SQC strategy can promote more effective, and not necessarily more frequent, IQC.