Fibrin clot interference in a human chorionic gonadotrophin assay causing a false Down syndrome screening result.

Serum samples are generally used for the measurement of human chorionic gonadotrophin (hCG) to calculate second-trimester maternal screening results. Lower hCG concentrations correlate with a lower calculated risk of Down syndrome (DS). Hence, erroneously low hCG results due to fibrin clot may lead to misinterpretation. We present a 23-year-old woman with a pregnancy of 17+3 weeks. Blood was taken into the Becton-Dickinson (BD) vacutainer SST-II Advance tube (Ref: 367955). The hCG test was performed on Immulite 2000 XPi analyser (Siemens Healthcare Diagnostics Inc, Tarrytown, USA) with original reagents. The results of the same sample were found as 2566 U/L, 18,153 U/L, and 7748 U/L. Three consecutive results after removal of the small fibrin clot and recentrifugation were 18,878, 20,255, and 22,339 U/L. The risk of DS and MoM for the concentration of 2556 U/L hCG was < 1/10,000 and 0.14, respectively. For a hCG concentration of 20,255 U/L, these values were 1/5632 and 1.13, respectively. Laboratory professionals and technicians should be aware that erroneously low hCG results can be measured with the Immulite 2000 XPi due to interference from small fibrin clots. Falsely underestimated hCG values reduce the MoM values and thus the calculated risk of DS.

Analytical performance evaluation of sensitive and old generation reagent in routine practical use: estradiol experience.

Evaluation of the analytical performance of tests in medical laboratories is important. Total Error (TE) and sigma analysis have been used as a quantitative indicator of quality for many years. The aim of this study is to evaluate the analytical performance of Beckman Coulter Access Estradiol (E2) and Sensitive E2 reagents. Analytical performance of two reagents were evaluated with TE, six sigma and measurement uncertainty values. Two Beckman Coulter Unicel DxI-800 autoanalyzers (A1 and A2) included in the study. Quality control data between December 2017 and December 2019 were used. CLIA-2019 values were used for total allowable error (TEa) limits. Uncertainty values were calculated with ISO/TS 20914. The median TE of the old generation and sensitive E2 reagent were 27.46% (between 13.49 and 48.88) and 11.16% (between 7.08 and 24.81), respectively (p < .005) The process sigma results were below 3 sigma in all months with the old reagent, whereas with the new reagents it was seen to be above 3 sigma in 11 of 12 months for both autoanalyzers. Uncertainty of old reagent is higher than new reagent. Imprecisions decrease as concentration increases with both reagents. The uncertainty values of low concentration levels are greater than high concentration levels. In conclusion, in both auto analyzers, Sensitive E2 reagent was found to have better performance than old reagent in terms of TE, process sigma and measurement uncertainty. We believe that the sensitive E2 reagent still needs further improvement for patients who have low E2 levels.

Reference change value and measurement uncertainty in the evaluation of tumor markers.

The use of measurement uncertainty among clinical laboratories becomes widespread. Measurement uncertainty can be reported with the result, as well as be used in certain reference change value (RCV) calculation equations. RCV is especially recommended for use in tests with a low individuality index. In our study, we calculated the measurement uncertainty of AFP, CA 125, CA 15-3, CA 19-9, CEA tumor markers with the ISO TS 20914:2019. We compared results with limits. Two Beckman Coulter DXI-800 (Minnesota, USA) autoanalysers' results were used. We calculated the RCV values using the classical Fraser method, logarithmic Lund Method, and Clinical Laboratory Standards Institute (CLSI) method as Minimal Difference (MD). We found the same permissible measurement uncertainty limit as 15.97% for all five tumor markers. The highest RCV value was found as 90% upstream for AFP test with Lund logarithmic approach, the lowest RCV value was found as 12% for CEA with MD, all other RCV results were between these two values. We do not recommend the use of MD, as values for Biological variation are not used in the MD approach. We also recommend using the logarithmic approach, although it gives higher results. There are also clinical studies on the significance of tumor markers in a follow-up that show different results. These differences may be because the studies are conducted with different systems. Therefore, each laboratory needs to calculate its own RCV values. We also recommend informing the clinicians about the tests with high measurement uncertainty.

Effects of different lipid emulsions on serum adipokines, inflammatory markers and mortality in critically ill patients with sepsis: A prospective observational cohort study.

BACKGROUND & AIMS: Intravenous lipid emulsions in parenteral nutrition may cause different metabolic responses and immune effects in critically ill patients with sepsis. The aim of this study is to investigate the effects of different lipid emulsions on changes in concentrations of adipokine and cytokine and their relationship with mortality in patients. METHODS: Patients enrolled in this prospective, single-center, observational cohort study, were estimated to require more than ten days of parenteral nutrition. They were treated with soybean oil-based or olive oil-based parenteral lipid emulsions. Adipokine and cytokine concentrations of septic patients were determined at enrollment and ten days after, in accordance with the diagnostic criteria of SEPSIS-3. The concentrations levels were measured in an enzyme-linked immunosorbent assay. Mortality was analyzed using the Kaplan-Meier method and Cox regressions. RESULTS: Over a 25-month period, 145 patients were assessed for eligibility and consequently, 40 patients were analyzed. On admission, both groups had comparable physiological scores, comorbidities, malnutrition risk, anthropometric measurements, metabolic/hematologic biomarkers and concentrations of adipokines and cytokines (p > .05). Serum leptin, resistin, and cytokines (IL-6, IL-10, IL-1ß and TNF-α) decreased significantly in the entire cohort over ten days following sepsis (p < .05). Serum resistin decreased in both olive oil-based and soybean oil-based lipid emulsions groups. Serum adiponectin only decreased in soybean oil-based lipid emulsions group (p < .05). There was association between survival and percentage changes in adiponectin, resistin and visfatin concentrations (log rank test: p < .05). CONCLUSION: Adipokine and cytokine responses are affected by medical nutritional therapy in the sepsis process and adipokines may represent functional prognostic biomarkers in critically ill patients with sepsis.

Direct radionuclide cystography imaging in colovesical fistula due to inguinal hernia operation complication.

Colovesical fistula is an abnormal connection between the enteric and urinary systems, usually sigmoid colon, caused by various conditions. One cause of colovesical fistula is iatrogenic injury, such as induced by inguinal hernia surgery. We present a case of colovesical fistula. A 57-year-old male was admitted to a local hospital with complaints of dysuria and pneumaturia. He had a past history of total extraperitoneal laparoscopic inguinal hernia repair operation 7 years previously for bilateral inguinal hernia. The case was assessed with radiologic and scintigraphic techniques. Radiologic techniques (plain abdominal radiography, intravenous pyelogram, ultrasound examination, double-contrast barium enema, CT, MRI) were inadequate to determine the colovesical fistula. The colovesical fistula was visualized with direct radionuclide voiding cystography as an alternative scintigraphic method.