Practical Laboratory Medicine最新文献

Objective

This study aimed to establish the reference intervals of Cyfra21-1 and CEA for the local screening populations using a chemiluminescence method.

Methods

A total of 4845 healthy adults and 190 lung cancer patients were included from the First Hospital of Hebei Medical University. The levels of Cyfra21-1 and CEA were measured to establish the local reference intervals.

Results

The upper limit reference intervals for Cyfra21-1 and CEA were determined as 3.19 ng/ml and 3.13 ng/ml, respectively. Notably, both Cyfra21-1 and CEA levels were found to be higher in males than in females. Additionally, both biomarkers showed an increasing trend with age.

In terms of diagnostic efficacy, the receiver operating characteristic (ROC) curve areas for Cyfra21-1, CEA, and their combination in lung cancer were 0.86, 0.73, and 0.91, respectively.

Conclusion

Our study revealed that the reference intervals of Cyfra21-1 and CEA in the local population differed from the established reference intervals. Furthermore, both biomarkers exhibited gender-dependent variations and demonstrated a positive correlation with age. Combining the two biomarkers showed potential for improving the diagnosis rate of lung cancer.

Introduction

Sexually transmitted infections (STIs) are among the most common infectious diseases worldwide, often leading to coinfections. Timely detection of genital tract pathogens in at-risk populations is crucial for preventing STIs. We evaluated the NAP-Fluo Cycler System, an innovative microfluidic nucleic acid detection platform, for its ability to simultaneously identify Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Ureaplasma urealyticum (UU), Mycoplasma genitalium (MG), and Mycoplasma hominis (MH) in urethral or cervical secretions.

Materials and methods

The limits of detection (LODs), repeatability, specificity, and interference resistance of the system were evaluated using standard strains, a panel of 24 pathogens, and seven interferents. We used the system to analyze 302 clinical samples and compared the results with those of five approved commercial reference kits.

Results

The system achieved LODs of 500 IFU/mL, 500 CFU/mL, and 500 CCU/mL for CT, NG, and UU/MG/MH, respectively, demonstrating high stability (coefficient of variation <1.1 %), specificity, and resistance to interference. Among 302 clinical samples, 237 tested positive with single, dual, and triple infection rates of 35.6 %, 16.2 %, and 3.0 %, respectively. The reference kits detected 138 positive samples. The concordance rates with commercial reference kits were 100 % for UU, NG, and MH; 94.85 % for CT; and 80.00 % for MG.

Conclusions

This system offers a streamlined, rapid, and multiplex detection method that reduces testing time and complexity. Although it performs well with pure strains, it has limitations when using clinical samples of CT and MG, suggesting the need for further refinement before its widespread use in the clinic.

Introduction

Recently, a flow cytometric (FC) based test has been developed for detection of circulating fetal cells to replace the less accurate and reproducible Kleihauer-Betke test.

FC test is easier to perform, it can distinguish the origin of fetal cells, but it is expensive and available in highly specialized laboratories. We evaluated the introduction of high-performance liquid chromatography (HPLC) approach as initial screening to identify patients who need an additional FC test to better discriminate the nature of haemoglobin-F (HbF) positive cells.

Methods

Blood samples from 130 pregnant women suspected to have fetomaternal haemorrhage were analysed with HPLC and FC methods. The cut-off for HbF HPLC concentration was calculated. Statistical analyses for the evaluation of HPLC as a screening method were performed. The positivity cut-off of HbF to be used as decision-making value to continue the investigation was calculated.

Results

An excellent agreement (R² > 0.90) was observed between the percentage of HbF obtained by HPLC and the percentage of fetal cells detected by FC. Results obtained from each assay were compared to define the HPLC threshold below which it is not necessary to continue the investigations, confirming the maternal nature of the HbF positive cells detected. Our study demonstrated that a cut-off of 1.0 % HbF obtained by HPLC was associated with the lowest rate of false negative results in our patient cohort.

Conclusions

This study provides a new FMH investigation approach that possibly leads to a reduction in times and costs of the analysis.

Background

The advent of CFTR modulators highlighted that the sweat test (ST) for CF can be used also as an outcome measure for the basic defect of CFTR. Despite the technological advances, ST still remains operator-dependent and its execution should be strongly paired with guidelines. In 2022, due to the advent of CFTR modulators, the Italian CF Society introduced a specific ST report. The aim of the present paper is to discuss the impact of this new report in the 2022-23 round of the Italian External Quality Assessment program for ST (I-EQA-SCT).

Methods

The scheme of the I-EQA-SCT is prospective, enrolment is voluntary, the payment of a fee is required and results are shared through a web-facility. Assessment covers analysis, interpretation, and reporting of results. In the 2022-23 round, 2 out of the 3 mock clinical information referred to patients who started modulators.

Results

Fourteen laboratories completed the 2022-23 I-EQA-SCT round. Three of them failed in the interpretation of results from these two mock cases and/or used a wrong report not consistent with the more recent Italian Sweat Test Recommendations.

Conclusions

The overall results obtained from the laboratories involved in the I-EQA-SCT program clearly showed that the laboratories’ qualitative and quantitative performance improved significantly. Results emerged from this round highlighted an issue in the report form used for monitoring patients on CFTR modulator therapy thus stressing the importance of these programs in improving both the performance of lab services and ameliorating the sweat test recommendations.

Background

Hemoglobin A1c (HbA1c) serves as a pivotal marker for long-term glycemic control. The Diabetes Control and Complications Trial (DCCT) established its relevance, yet gaps exist in understanding potential seasonal variations in HbA1c levels among diabetic patients. The study highlights the need to explore potential seasonal variations in HbA1c levels and their impact on diabetic patients.

Materials and methods

This is an observational study conducted in a tertiary care hospital from January to December 2019, the study analyzed HbA1c levels in 8138 patients. Blood samples were collected using Potassium EDTA-containing vials and processed with an automated analyzer. Seasonal variations were explored using time series analysis.

Results

Mean HbA1c levels peaked during the monsoon (June to September) and were lowest in autumn (October to November). Subgroup analysis revealed differences in patients with HbA1c values below and above 6.5 %. Those with controlled blood sugar showed higher levels in winter (December to February) and monsoon (June to September), while patients with HbA1c values ≥ 6.5 % exhibited significantly lower levels in monsoon (June to September) and autumn (October to November) compared to summer (March to May).

Conclusion

In contrast to global trends, Indian patients demonstrated distinct seasonal variations in HbA1c levels. The highest levels during the monsoon (June to September) may be linked to reduced outdoor activity and dietary changes. The study emphasizes the need for tailored diabetes management considering seasonal influences. Further extensive, longitudinal studies across diverse Indian regions are recommended to comprehensively grasp the impact of seasonal changes on diabetes outcomes.

Background

Pulmonary embolism (PE) poses a significant challenge in diagnosis and treatment, particularly in high-risk patient populations such as those hospitalized for orthopedic reasons. This study explores the predictive and diagnostic potential of laboratory parameters in identifying PE among orthopedic patients.

Objectives

The purpose of this study was to determine whether selected (inexpensive and readily available) laboratory parameters and their coefficients can be used to diagnose pulmonary embolism and whether they are applicable in predicting its occurrence.

Material and methods

Selected laboratory parameters were determined twice in 276 hospitalized orthopedic patients with suspected PE: PLT, MPV, NEU, LYM, D-dimer, troponin I, age-adjusted D-dimer and their coefficients. Depending on the angio-CT results, patients were divided into groups. Selected popular laboratory coefficients were calculated and statistically analyzed. Optimal cutoff points were determined for the above laboratory tests and ROC curves were plotted.

Results

D-dimer/troponin I [p = 0.008], D-dimer [p = 0.001], age-adjusted D-dimer [p = 0.007], NLR/D-dimer [p = 0.005] and PLR [p = 0.021] are statistically significant predictors of PE. D-dimer/troponin I [p < 0.001], troponin I [p = 0.005] and age-adjusted D-dimer [p = 0.001] correlated with the diagnosis of PE after the onset of clinical symptoms.

Conclusions

In the context of orthopedic patients, cost-effective laboratory parameters, particularly the D-dimer/troponin I ratio and age-adjusted D-dimer, exhibit considerable potential in predicting and diagnosing PE. These findings suggest that combining readily available laboratory tests with clinical observation can offer a viable and cost-effective diagnostic alternative, especially in resource-constrained settings. Further studies with larger and diverse patient populations are recommended to validate these results.

a) Objectives

Dopamine is known to cause negative interference on enzymatic creatinine measurement. However, its effect on the Jaffe reaction, and its concentration required to interfere with enzymatic reactions, remain uncertain. This study was designed to study the interference of stable dopamine infusion on Jaffe and enzymatic creatinine assays, as well as the effect of dopamine infusion drip arm contamination on both creatinine assays.

b) Design and Methods

For the first part of the study, dopamine was spiked into pooled plasma samples at different concentrations to mimic the scenario of patients on dopamine infusion at an infusion rate between 2 and 20 μg/kg/min. For the second part, dopamine preparation of 2 g/L (same as the preparation used clinically) was mixed with pooled plasma samples at different proportions to mimic drip arm contamination. Creatinine concentrations were measured using Jaffe and enzymatic reactions.

c) Results

The first part showed that creatinine measurements were not interfered by dopamine infusion at an infusion rate between 2 and 20 μg/kg/min. The second part showed that dopamine could negatively interfere with enzymatic creatinine assays, even with minute drip arm contamination. The effect on the Jaffe reaction was less significant.

d) Discussion

Creatinine concentration could be reliably measured by Jaffe or enzymatic reactions if samples are from venous access sites other than the site of dopamine infusion. When dopamine interference on enzymatic creatinine assays is suspected, using the Jaffe reaction to cross-check may provide additional useful information.

Prader-Willi syndrome (PWS) is a complex genetic disorder caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region, known as the Prader Willi critical region. Nutritional clinical manifestations change with age and are described in four different phases. The phases span both extremes of the nutritional spectrum, beginning with an infant with poor sucking reflexes and failure to thrive then progressing to an adolescent who may have hyperphagia and be at risk for obesity. The phenotype is likely due to hypothalamic dysfunction due to genetic changes in the Prader Willi critical region. Researchers are examining the pathological mechanisms that determine the disease course.

Insulin degrading enzyme (IDE) plays a critical role in degrading insulin and beta-forming proteins, implicating its significance as a biomarker in metabolic dysfunction and neurocognitive disorders, including Alzheimer's disease (AD). Understanding the impact of pre-analytic conditions of in vitro IDE levels is imperative for reliable biomarker assessment. This study explored the influence of freeze-thaw cycles, storage temperature, and storage time on IDE levels in human serum.

Serum samples from seven healthy volunteers were subjected to various storage conditions, including refrigeration (4 °C) and freezing (−20 °C and −80 °C) for 24 h and six months, with differing freeze-thaw cycles. In vitro IDE levels were measured at 24 h and after 6 months using ELISA.

Results indicate that while short-term storage at either −20 °C or −80 °C yielded similar IDE levels, prolonged storage and multiple freeze-thaw cycles significantly impacted IDE stability, with colder temperatures exhibiting better preservation.

Although further research with larger cohorts and longer storage time is warranted to establish clinical significance, our study suggests preferential use of unthawed samples or consistent freeze-thaw conditions for accurate IDE assessment. Thus, optimizing sample storage conditions is paramount for reliable IDE biomarker analysis in clinical and research settings.

Background

The plasma concentration of 5-Fluorouracil (5-FU) is affected by numerous factors, thereby limiting its efficacy. The current therapeutic regimen's doses based on body surface area (BSA) are linked to increased toxicity and sometimes inadequate drug exposure.

Aim and objectives

The study aims to develop an in-vitro assay to monitor 5-Fluorouracil's therapeutic efficacy in cancer patients' blood samples, focusing on pharmacokinetics to improve therapy precision.

Materials and methods

Drug levels were determined from standards, quality controls, and experimental samples using protein precipitation, liquid-liquid extraction, and separation using a C18 analytical column with an isocratic program.

Result

In EXP-1A, the mean concentration of 5-Fluorouracil was 1.15 μg/ml; in EXP-1B, it was 1.16 μg/ml, while in EXP-1C, the mean concentration was 0.9 μg/ml. The percentage difference in mean 5-Fluorouracil concentration between the experiment sample containing a DPD inactivator and EXP-1C (without a DPD inactivator) was 21.5 % higher for EXP-1A and 0.68 % higher for EXP-1B. In the second phase of the experiment, the overall stability of 5-Fluorouracil in samples containing a DPD inactivator was 24.5 % superior compared to samples without a DPD inactivator.

Conclusion

A modified extraction technique has been developed to accurately measure 5-Flourouracil concentration in blood, preserving its stability and concentration by adding a DPD inactivator.