Background: The Laboratory Medicine Foundation (LMF) checklists explain the accreditation requirements of the program and reflect quality standards like those of the Clinical Laboratory Standards Institute (CLSI) or quality system essentials (QSE) of the World Health Organization (WHO). In this study, we have analyzed how the LMF checklists correlate with the 12 QSE elements of the WHO. Methods: The LMF checklists for laboratory management (LM) (version 2019) were classified into the 12 specific QSE elements by five laboratory physicians. Each checklist item was classified into specific element if four or more participants agreed, and into overlapping elements when two or more of them agreed for two different items. Any changes in checklist items and chapter structuring of the checklist since 2009 were investigated. Results: The LM checklists consisted of 183 checklist items, including 20 (10.9%) classified into overlapping QSE elements. The QSE element with the highest number of items was the facilities and safety (62, 33.9%), followed by the personnel (22, 12.0%), and the process control (17, 9.3%). In contrast, QSE elements with the lowest number of items were the customer service (4, 2.2%) and process improvement (4, 2.2%). Items belonging to the customer service and the organization elements have increased since 2017. Conclusions The LMF checklists reflect current quality goals for clinical laboratories and play a leading role in the laboratory's quality improvement. The results of our study will be of help in potentiating the quality leader role of LMF checklists, and international harmonization of our laboratory accreditation program.

Chromosome 4q deletion syndrome is a rare disease caused by partial deletion of the long arm of chromosome 4. Phenotypic severity and expressivity vary among patients with chromosome 4q deletions, depending on the size and region of the deletion of the affected chromosome. Although there have been many reports of proximal 4q deletion cases, very few have been confirmed by high-resolution array comparative genomic hybridization (aCGH). In the current study, we presented a new case of 4q proximal deletion, with detailed genetic and clinical characteristics, and compared these characteristics to those of six previous cases with available aCGH data. According to our review, several genes known to be associated with specific phenotypes of 4q12q21.1 deletion cannot sufficiently explain the variable phenotypes observed among the cases. These phenotypes include mental retardation, microcephaly, ocular anomalies, dental anomaly, and piebaldism. Consequently, we recommend further detailed investigations into the genes associated with 4q12q21.1 deletion to assist in identifying genotype-phenotype associations more clearly.

Background: Clinical specimens are valuable materials that require a traceable management system. Maintenance of temperature and loss prevention during transport are important for the reliability of the clinical test results. Current transportation systems can suffer from temperature changes and agitation. Quality improvement in this pre-analytic phase is required. This study acquired preliminary data from a newly developed specimen transportation system adopting a real-time temperature monitoring during transportation using temperature sensor and global positioning system to establish appropriate guidelines. Methods: Temperature preservation performance was compared between two transportation boxes (newly developed one [A] and conventional one [B]) at exterior temperatures of 35℃ and ?18℃, reflecting the extreme temperature range in Korea. Influences of the temperatures on analytical results of whole blood, serum, plasma, and urine specimens were investigated, as were the effects of vibration. Results: The interior temperature of box A measured at multiple sites was maintained within 1.0?9.0℃ at both exterior temperatures. The interior temperature of box B was outside of this range. The analyzed parameters varied comparably with the variations occurring at the recommended and published storage temperature. Vibration affected nonspecific enolase and lactate dehydrogenase. Conclusions Temperature preservation and real-time monitoring during specimen transportation are important. The present data highlight the importance of transportation conditions and indicate that laboratories should know the characteristics of temperature changes in their transportation system.

Rapid influenza diagnostic test (RIDT) is widely used for the diagnosis of influenza owing to its simplicity and convenience of use. This study aimed to evaluate the performance of a new RIDT, SD Standard F influenza A/B FIA (SD Biosensor, Inc., Korea) (Standard F) and compare its performance with BD Veritor Flu A+B (Veritor), using the results of real-time reverse transcription PCR (rRT-PCR) analysis as the standard for reference. On comparing the results obtained from both the RIDTs and rRT-PCR qualitatively, it was found that the Veritor and Standard F assays have the sensitivity of 65.6% (21/32) and 71.9% (23/32), respectively, for the detection of influenza A with a specificity of 100.0% (68/68). Additionally, both the assays demonstrated a sensitivity of 66.7% (12/18) and specificity of 100.0% (68/68) for the detection of influenza B. The cutoff index (COI) value of the fluorescence color intensity from the Standard F assay, displayed on the device along with the qualitative results, indicated a negative correlation with the Ct value from rRT-PCR for both influenza A and B (P<0.001). The sensitivity of the new RIDT for the detection of influenza was comparable with that of the Veritor assay and the new RIDT could be used as a substitute for existing RIDTs by providing additional information to predict the approximate viral burden of influenza.

Gorlin–Goltz syndrome, also known as basal cell nevus syndrome, is a condition that affects several body parts and increases the risk of developing various cancerous and noncancerous tumors. This syndrome is mostly caused by the pathogenic variants of the PTCH1 and SUFU genes; however, it is rarely diagnosed due to limited prevalence. PTCH2 has rarely been identified as a pathogenic variant in patients with the Gorlin–Goltz syndrome in China and Japan. Here, we report the case of a 30-year-old woman who was diagnosed with the Gorlin–Goltz syndrome—based on multiple calcifications on the body—who carried a frame shift pathogenic variant of the PTCH2 gene (c.1172_1173del) identified via whole exome sequencing. The patient did not present the typical phenotypes of the Gorlin–Goltz syndrome, such as basal cell carcinoma, palmar/plantar pits, macrocephaly, and keratocystic odontogenic tumors. Based on these observations, we suggest that a pathogenic variant of PTCH2 can manifest a milder phenotype of the Gorlin–Goltz syndrome.

The demand for obtaining test results using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for accurate diagnosis in the field of laboratory medicine is expected to increase, but it is still not easy to introduce diagnostic methods using LC-MS/MS into clinical laboratories for many reasons. There are many different methods used to evaluate the performance of LC-MS/MS in clinical laboratories, which have not been standardized to date. Thus, various data have been analyzed and described based on the type of validation method used and the criteria needed to introduce a new test using LC-MS/MS in a clinical laboratory. Relevant data from home and abroad were reviewed to include the minimum number of validation items required and methods of implementation. In general, the items required for a full validation of the quantitative test and various guidelines were used to summarize the following validation items: accuracy, precision, calibration, specificity, ion suppression or improvement, limit of detection, limit of quantification, stability, reference interval, carryover, and dilution integrity. Among these, the first five items mentioned beforehand are essential parameters for LC-MS/MS validation and are presented in numerous guidelines. The other parameters are required for further verification depending on the characteristics of the analysis and the analytes. This recommendation is intended to outline and present the validation methods that should be carried out when introducing new tests in clinical laboratories using LC-MS/MS with reference to the existing guidelines and literature containing expert opinions.

Background: Intraoperative measurement of intact parathyroid hormone (iPTH) levels is crucial for confirming complete removal of hyperfunctioning parathyroid glands during parathyroidectomy and for detecting parathyroid gland damage during thyroidectomy. The use of plasma samples can shorten the turnaround time (TAT) for iPTH. The present study explored the effectiveness of using plasma samples for iPTH quantitation by comparison with the corresponding serum samples. We also evaluated the analytical performance of iPTH. Methods: The TAT of plasma and serum samples analyzed in March 2019 was compared. In addition, comparative evaluation of the iPTH levels in 100 paired plasma and serum samples were performed. Analytical performances including within-run and within-laboratory precision, and linearity were evaluated in plasma samples using the ADVIA Centaur iPTH assay (Siemens Healthineers, Germany). The reference range was verified with plasma samples collected from 20 healthy adults. Results: Plasma iPTH tests showed shorter TAT values (P<0.001) and higher iPTH levels (P<0.001) than serum. Correlation analysis between plasma and serum iPTH levels showed a strong positive correlation (r=0.925). The within-run and within-laboratory precision values were within the manufacturer's recommendation. iPTH showed linearity from 5.1 to 1,670.0 pg/mL (R2=0.999). The plasma iPTH levels from 20 healthy adults were within the reference range, thus validating our method. Conclusions The plasma iPTH levels were higher than the serum levels, with a strong positive correlation. The TAT of plasma samples was considerably shorter than that of serum. iPTH quantitation from plasma samples is preferable when rapid results are required.

Background: Current methods for diagnosing Clostridioides difficile infections (CDIs) fail to provide information on their severity. Fecal neutrophil gelatinase-associated lipocalin (NGAL) and calprotectin are candidate biomarkers for evaluating the severity of intestinal inflammation. We assessed fecal NGAL and calprotectin levels in patients with CDI and compared these values between subgroups of patients. We also evaluated their utility in predicting CDI clinical outcomes. Methods: A total of 147 leftover fecal samples were obtained; 97 samples were from patients with CDI and 50 were from routine healthcare checkups. Fecal calprotectin and NGAL levels were measured using a Quantitative Fecal NGAL ELISA Kit and Quantitative Fecal Calprotectin ELISA Kit (Epitope Diagnostics, USA). Results: Significant differences in fecal NGAL and calprotectin levels were observed between CDI patients and healthy controls (P<0.0001 for both). Significant differences in fecal NGAL and calprotectin levels were also seen between patients with high and low tcdB gene load (P=0.005 and 0.006, respectively). Fecal calprotectin levels were lower in patients with leukopenia (P=0.002), and high calprotectin levels were associated with severe CDI and treatment failure (P=0.021 and 0.033, respectively). Conclusions Fecal NGAL and calprotectin levels were higher in patients with CDI than in healthy controls and correlated with high tcdB gene loads. Leukopenia patients with CDI had significantly lower levels of calprotectin and the assessment should be regarded with caution. High fecal calprotectin levels were also associated with severe CDI and treatment failure. This warrants future studies with more patients and in-depth analyses.

Background: Hematologic malignancies have a relatively lower prevalence than major solid cancers, although the incidence of hematologic malignancies has significantly increased in recent years. However, understanding the current status of hematologic malignancy is significantly challenging because basic data regarding this malignancy are insufficient in the Korean population. Methods: From 2005 to 2015, the status of seven codes of hematologic malignancy, containing 24 subcodes defined using a classification defined by the Korean Classification of Disease-6, was analyzed. The number of new patients, crude incidence rate, prevalence rate, and age-standardized incidence rate were also investigated. Results were analyzed based on National Health Insurance Service (NHIS) data. Results: The number of new patients showed an overall increase over time and a rate of increase up to 56.7% for 10 years. The number of male patients was higher than that of female patients, with the majority of patients aged greater than 60 years. The incidence and prevalence rates have increased steadily. Conclusions Consistent with the previous studies, this study might be useful to understand the current status of hematologic malignancy and might contribute to the improvement of national public healthcare.