Clinical laboratory最新文献

Background: Recombinase polymerase amplification (RPA) is a novel nucleic acid isothermal amplification technique that can achieve rapid detection of the target, under 37 to 42°C conditions, within 30 minutes. It has the advantage of extreme sensitivity, strong specificity, and low instrument dependency and is particularly suitable for real-time detection in the field. It can be widely used in fields such as in vitro diagnostics, biosafety, and agriculture. This study was based on RPA technology, targeting the gyrA gene of Neisseria gonorrhoeae (N. gonorrhoeae), to establish a quick, accurate, and easy to operate method for detecting N. gonorrhoeae and to evaluate its specificity, sensitivity, and clinical, practical value.

Methods: Specific primers and probes suitable for RPA and qPCR methods based on the specific conserved region of the gyrA gene of N. gonorrhoeae on GenBank (no. U08817.1) were designed An RPA method was developed and N. gonorrhoeae ATCC49226 and a number of clinical isolates were used as study subjects to validate the specificity and sensitivity of the RPA method for the detection of N. gonorrhoeae. A real-time fluorescence quantitative polymerase chain reaction (qPCR) method, with N. gonorrhoeae ATCC49226 as the research object, was established to verify the sensitivity of qPCR method for detecting N. gonorrhoeae. Finally, clinical samples were tested by using RPA and qPCR methods as performance validation experiments to determine the clinical utility of the RPA technique in detecting N. gonorrhoeae.

Results: The established RPA detection method showed excellent specificity, with a specific amplification curve for N. gonorrhoeae alone, no cross-reactivity with other bacteria, and excellent reproducibility. The detection results could be obtained within 30 minutes, under the condition of 39°C, which was significantly lower than the detection time of traditional methods. The sensitivity of the RPA method for detecting pathogenic bacteria samples was 4 × 102 CFU/mL, which is consistent with the detection limit of qPCR methods. RPA and qPCR methods were used to detect 121 clinical isolates, out of which 30 strains of N. gonorrhoeae showed a specific amplification curve, while the remaining 91 strains of non-N. gonorrhoeae did not. Both methods had 100% accuracy and specificity in detecting N. gonorrhoeae.

Conclusions: The RPA method developed in this study has the characteristics of being quick, accurate, and easy to operate, which was of great value for the rapid detection of N. gonorrhoeae in clinical samples.

Background: Achieving first complete remission with induction chemotherapy (ICT) for acute myeloid leukemia (AML) correlates with patient's prognosis. This study aimed to determine the correlation between oxidative stress and the outcome of ICT in AML patients.

Methods: A total of 195 AML patients underwent initial ICT at the Longyan First Affiliated Hospital of Fujian Medical University from 06-11-2018 to 12-30-2023. Three weeks after ICT, patients were divided into two groups, CR (complete remission) and PR (partial remission), by detecting blood parameters and bone marrow cells. Serum oxidative stress-related factors, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and growth/differentiation factor-15 (GDF15) activities or levels were measured to assess the diagnostic value of these factors as a means of diagnosing the efficacy of ICT in patients. Factors affecting PR after initial ICT were analyzed.

Results: Patients in the PR group had higher levels of oxidative stress three weeks after initial ICT. Compared with the CR group, patients in the PR group had elevated levels of MDA and GDF15 and reduced activities of SOD, GSH-Px, and T-AOC. Serum MDA levels (AUC 0.709; 95% CI. 0.618 - 0.781) and the combination of multiple indicators (AUC 0.791; 95% CI. 704 - 0.851) had diagnostic value for the efficacy of AML patients undergoing ICT. Serum MDA and GDF15 exceeding cutoff values were risk factors for PR in AML patients undergoing ICT, as were serum SOD and T-AOC below cutoff values. Preoperative malnutrition was associated with PR in patients.

Conclusions: Serum oxidative stress-related factors in AML patients are helpful in detecting the efficacy of ICT. Oxidative stress in response to ICT is useful for characterizing the efficacy in AML patients after ICT.

Background: This study aimed to investigate the molecular epidemiological characteristics of hypervirulent Klebsiella pneumoniae (hvKp) in Yakeshi City, Hulunbuir, China, analyze the resistance of hvKp to commonly used antibiotics, explore independent risk factors for hvKp infection, and provide a research basis for anti-infection treatment.

Methods: In total, 519 strains of K. pneumoniae, identified by the Inner Mongolia Forestry General Hospital from January 2020 to December 2022, were collected, and high-viscosity (HMV-Kp) and non-HMV-Kp strains were differentiated using string test. PCR and agarose gel electrophoresis were used to detect the rmpA, rmpA2, and iutA genes to identify hvKp strains. Sixty strains of hvKp were randomly selected for capsular serotyping by PCR and agarose gel electrophoresis. Sanger sequencing was used to sequence the housekeeping genes of 60 hvKp strains and perform ST analysis. A minimum spanning tree was drawn using capsule serotyping and ST typing. Significant differences in resistance to commonly used antibiotics between classical K. pneumoniae (cKp) and hvKp were analyzed by using the chi-squared test. Finally, the risk factors for hvKp infection were analyzed through binary logistic regression.

Results: The HMV-Kp detection rate was 39.69%, versus 37.19% for hvKp. HMV-Kp accounted for 84.97% of all hvKp isolates. The hvKp detection rate was highest in the general surgery department. In capsule serotyping, K1 was the main subtype, accounting for 63.33% of all isolates (38/60), followed by K2 (16.67%, 10/60). Through ST typing, 18 subtypes were detected, with ST23 being the most common (50.00%), followed by ST86 (8.33%), and the remaining subtypes were scattered throughout the distribution. Compared with cKp, hvKp strains exhibited higher sensitivity to commonly used antibiotics, excluding furantoin. Male gender (odds ratio (OR) = 1.977), liver abscess (OR = 15.019), and the use of macrolide antibiotics in the past 3 months (OR = 5.473) were independent risk factors for hvKp infection.

Conclusions: The hvKp detection rate in the local area was 37.19%, and a strong correlation was noted between hvKp and HMV-Kp strains. K1-ST23 was the dominant subtype in this study. Compared with cKp, hvKp strains were more sensitive to commonly used antibiotics. Male gender, liver abscess, suppuration or infection of other tissues and organs, and recent macrolide antibiotic use were risk factors for hvKp infection.

Background: In areas where C. sinensis is endemic, early screening and diagnosis of C. sinensis infection is crucial to prevent complications and interrupt the chain of transmission. Testing for C. sinensis IgG antibodies is frequently employed as a screening method for detecting the disease. However, its effectiveness in populations with a high risk remains to be determined. This study aimed to evaluate the clinical value of IgG antibody testing for screening C. sinensis infection in high-risk populations.

Methods: Between October 2020 and September 2023, 1,080 participants from Liuzhou Municipal Liutie Central Hospital patients were recruited. All participants underwent enzyme-linked immunosorbent assay (ELISA) to detect IgG antibodies and fecal examination for C. sinensis eggs using the Kato-Katz technique. The study examined the diagnostic concordance between two methods by using inter-rater agreement evaluation (Kappa). The diagnostic effectiveness of IgG antibodies was assessed comprehensively and across different gender and age categories, with the outcomes of the parasite egg test serving as the benchmark for diagnosis.

Results: Out of the 1,080 participants, 48.0% (518/1,080) tested positive for C. sinensis eggs, and 46.9% (506/1,080) tested positive for IgG antibodies. The Kappa value of the two methods' diagnostic concordance was 0.599. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of IgG antibody detection were 78.0%, 81.9%, 79.8%, 80.1%, and 80.0%, respectively, using C. sinensis eggs as the diagnostic criterion. Gender and age subgroup analyses revealed that diagnostic specificity, negative predictive value (NPV), and accuracy were higher in females than males (p = 0.003, 0.001, and 0.049, respectively). Sensitivity tended to decrease, while specificity tended to increase with age (p = 0.007 and 0.010, respectively).

Conclusions: The technique for detecting Clonorchiasis IgG antibodies has a certain degree of accuracy in diagnosing C. sinensis, but its sensitivity is low, particularly in mild infections and in the elderly population. Diagnosis requires a combination of other assays or further optimization of the technique's performance.

Background: Researching medical sample storage is crucial for maintaining the integrity of biological specimens and ensuring the accuracy of research investigations and diagnostic tests. Improper storage conditions can lead to sample degradation, compromising the reliability of results. Standardized storage procedures are essential for quality control, particularly in multicenter trials where samples are collected and processed at various locations. Moreover, ethical considerations dictate careful handling of patient samples to uphold privacy and rights.

Methods: This study focuses on the surface phenotype of T cells, which is vital for diagnosing immunodeficiency disorders and autoimmune diseases and for monitoring disease activity and treatment efficacy. The effect of storage duration on T cell surface proteins is multifactorial, influenced by factors like protein degradation, cellular metabolism, and cytokine release. Long-term storage can lead to the gradual loss of T cell function, necessitating techniques to preserve cell activity. Changes in surface markers can affect disease diagnosis, emphasizing the importance of accurate sample processing.

Results: Findings from this study reveal time-dependent changes in T cell surface markers during storage. CD3 levels declined significantly after the fourth day, with FITC labeling proving superior to APC. CD4 levels remained consistent until the fourth day, contrasting with previous findings on foreskin tissue. HLA-DR levels declined rapidly, indicating unsuitability for storage, consistent with other studies on cryopreserved cells. CD16 and CD8 levels decreased gradually, while CD56 declined rapidly after the third day, consistent with recent research.

Conclusions: There were detectable and significant differences after the samples were stored for an improper period, which may have affected the integrity of the results, suggesting that understanding the factors influencing T cell surface protein changes during storage is crucial for maintaining result integrity.

Backgrounds: AML patients with FLT3-ITD mutation experience a poor prognosis. Our study evaluated the clini¬cal characteristics, remission, relapse, and clinical outcomes of these patients. We also assessed the effectiveness of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and sorafenib in treating AML patients with FLT3-ITD mutation.

Methods: Fifty-five newly diagnosed AML patients with FLT3-ITD mutation in our center were retrospectively enrolled between January 2018 and June 2023. Multiple fusion genes and gene mutations were identified for the diagnosis of AML. Survival curves were calculated by employing the Kaplan-Meier method, and the differences between them were evaluated by using the log-rank (Mantel-Cox) test.

Results: Twenty-seven patients underwent allo-HSCT. The allo-HSCT group had a significantly extended follow-up period compared to the non-HSCT group (p < 0.001). Mutations in both NPM1 and FLT3-ITD were present in 18 out of the 55 patients (32.7%). Among them, eleven patients were given sorafenib plus chemotherapy induction therapy, and forty-four received mono-chemotherapy. The HSCT group had a higher overall survival (OS) rate than the non-HSCT group (p < 0.001), and a higher relapse-free survival (RFS) rate as well (p = 0.0017). No statistically significant difference in OS and RFS was observed when compared with sorafenib plus chemotherapy and mono-chemotherapy (p > 0.05). FLT3-ITD-positive patients with and without NPM1 mutation did not experience a significant difference in OS and RFS rates (p > 0.05).

Conclusions: Allo-HSCT immediately following complete remission could improve outcomes for young adults diagnosed with FLT3-ITD-positive AML. However, we found no statistical difference in the overall response rate (ORR) and clinical outcome between sorafenib combined with chemotherapy and chemotherapy alone.

Background: This study aimed to analyze the distribution of multidrug-resistant (MDR) organisms (MDROs) in patients with diabetic foot ulcers (DFUs) and to identify risk factors for MDRO infections.

Methods: Patients hospitalized with DFUs were enrolled, and ulcer swabs were cultured for bacterial identification and antibiotic susceptibility testing. Hematology and blood biochemistry were also assessed.

Results: A total of 228 patients hospitalized with DFUs were enrolled. Out of 150 patients with positive cultures, 123 (82%) were infected with single strains, whereas 27 (18%) had mixed infections. Out of the 177 bacterial strains isolated, 78 (44%) were MDROs. Among the top 5 most common bacteria, coagulase-negative Staphylococcus, Staphylococcus aureus, and Proteus exhibited MDR rates of 92%, 56%, and 55%, respectively. Pseudomonas aeruginosa and Enterobacter cloacae had low MDR rates of 5% and 8%, respectively. Single variable logistic regression analysis showed that neutrophil percent (NEU%), creatinine, C-reactive protein, and fasting plasma glucose (FPG) were risk factors for MDRO infection, whereas hemoglobin and albumin levels were protective factors. Multivariable logistic regression analysis revealed that NEU% and FPG were independent risk factors for MDRO infection.

Conclusions: A high percentage of the infections in patients with DFUs were caused by MDROs. To reduce MDRO infections in high-risk patients, it is important to use antibiotics rationally, improve patients' FPG levels and nutritional status, and strengthen hospital sterilization processes.

Background: This study aimed to establish reference intervals for two biomarkers actively utilized in routine annual medical check-ups in China: squamous cell carcinoma antigen (SCCA) and cytokeratin 19 fragment (CYRFA 21-1), and to understand the influence of age, gender, and benign nodule(s) on their levels.

Methods: This prospective multicenter cross-sectional study continuously enrolled apparently healthy adults attending annual medical check-ups at three sites in 2019. Serum SCCA and CYFRA 21-1 levels were measured using electrochemiluminescence immunoassays. Age- and gender-specific reference intervals for the two biomarkers were established by using the 0 - 95th percentiles with 90% confidence intervals (CIs). The 97.5th percentiles were also provided.

Results: A total of 1,017 subjects were enrolled in this study. Both biomarkers were significantly lower in females, and age was negatively associated with SCCA while positively associated with CYFRA 21-1 (all p < 0.0001). No statistically significant differences were determined between subgroups without/with benign nodule(s) despite nodule(s) status (all p > 0.05). The overall reference interval for SCCA is 0 - 2.64 ng/mL and 0 - 4.39 ng/mL for CYFRA 21-1. The age-specific reference intervals for SCCA are 0 - 2.76 ng/mL (18 - 49 years) and 0 - 2.22 ng/mL (≥ 50 years), and for CYFRA 21-1, they are 0 - 3.86 ng/mL (18 - 49 years) and 0 - 4.89 ng/mL (≥ 50 years). The gender-specific reference intervals for SCCA are 0 - 2.83 ng/mL (male) and 0 - 2.49 ng/mL (female), and for CYFRA 21-1, they are 0 - 4.34 ng/mL (male) and 0 - 4.45 ng/mL (female).

Conclusions: The reference intervals for SCCA and CYFRA 21-1 established in this study could be utilized in annual medical check-ups and contribute to the screening of lung cancer in China.

Background: CK-MB is a subtype of creatine kinase isoenzyme, mainly present in myocardial tissue. When myocardial tissue damage is severe, CK-MB is released into the blood, and the serum level significantly increases, which is an important indicator for diagnosing acute myocardial infarction.

Methods: We reported a case of pseudo-elevation of CK-MB without acute myocardial infarction.

Results: The immunosuppressive assay showed that the activity of CK-MB isoenzyme was 903.0 U/L, which was significantly increased. The patient underwent examinations such as cardiac ultrasound and coronary artery imaging, and no obvious abnormalities were found. Suspected interference, CK-MB was measured using mass immunoassay, and the result was 1.96 ng/mL, which is within the normal range.

Conclusions: When the CK-MB level (immunosuppressive assay) abnormally increases but clinical examination does not support the diagnosis of acute myocardial infarction, laboratory personnel should be aware of the short-comings of this method and use mass immunoassay to detect CK-MB to eliminate interference, and avoid unnecessary examinations and treatments for patients due to inaccurate results.

Background: Vitamin D is a fat-soluble vitamin found in two forms, sourced either from plants (D2) or animals (D3). Numerous epidemiological studies worldwide have highlighted its deficiency across diverse populations in various countries. When coupled with obesity, this deficiency becomes a significant global health concern. Our study aimed to evaluate the vitamin D levels among obese individuals in Southern Morocco.

Methods: This is a retrospective, cross-sectional descriptive study on the vitamin D status in obese subjects. This study was conducted at the "Health Universe" Diet Center in Agadir, Morocco. The measurement method involved using a Tanita® wall-mounted metal stadiometer to determine height and a Tanita® BC 418 MA segmental body composition analyzer to determine weight. The serum level of 25-hydroxyvitamin D was determined by elec-trochemiluminescence (ECLIA) using the Elecsys® and Cobas e411®.

Results: The sample of our study, consisting of 1,210 individuals, is composed of 73.5% (n = 889) females and 26.5% (n = 321) males. The mean age of the entire sample is 42.3 ± 13.1 years (ranging from 18 to 86 years). The mean BMI is 37 ± 5.69 kg/m², with a higher value in females (37.4 ± 5.85 kg/m²) compared to males (35.7 ± 5.03 kg/m²), including 42.8% moderate obesity, 34.2% severe obesity, and 23% morbid obesity. The mean serum vitamin D level in our sample is 15.7 ± 7.67 ng/mL. This level is 14.5 ± 7.42 ng/mL for females and 19.2 ± 7.31 ng/mL for males. However, only 5.3% of the subjects have an adequate serum vitamin D level, while 18% have an insufficiency, 52.5% have a moderate deficiency, and 24.2% have a severe deficiency. An inverse trend was noted for BMI, which shows a very significant inverse correlation with serum vitamin D concentration (r = -0.18 and p < 0.01).

Conclusions: Our results support the hypothesis that obesity is inversely associated with low vitamin D levels. Lifestyle improvement should be considered as the primary treatment option, aiming to enhance the dysmetabolic state associated with obesity and vitamin D deficiency.