• Childhood Kidney Diseases
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• v.28 no.1
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• pp.16-26
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• 2024

Patients with kidney disease require frequent blood tests to monitor their kidney function, which is particularly difficult for young children and the elderly. For these people, the standard method is to evaluate serum creatinine or cystatin C or drug levels through venous sampling, but more recently, evaluation using dried blood spots has been used. This narrative review reports information from the literature on the use of dried blood spots to quantify the main markers used to detect kidney diseases. The ScienceDirect and PubMed databases were searched using the keywords: "dried blood on filter paper," "markers of renal function," "renal function," "creatinine," "cystatin C," "urea," "iohexol," and "iotalamate." Studies using animal samples were excluded, and only relevant articles in English or Spanish were considered. Creatinine was the most assessed biomarker in studies using dried blood spots to monitor kidney function, showing good performance in samples whose hematocrit levels were within normal reference values. According to the included studies, dried blood spots are a practical monitoring alternative for kidney disease. Validation parameters, such as sample and card type, volume, storage, internal patterns, and the effects of hematocrit are crucial to improving the reliability of these results.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3103-3106
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• 2014

• Parasites, Hosts and Diseases
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• v.59 no.1
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• pp.15-22
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• 2021

Artemisinin resistance (ART) has been confirmed in Greater Mekong Sub-region countries. Currently, C580Y mutation on Pfkelch13 gene is known as the molecular marker for the detection of ART. Rapid and accurate detection of ART in field study is essential to guide malaria containment and elimination interventions. A simple method for collection of malaria-infected blood is to spot the blood on filter paper and is fast and easy for transportation and storage in the field study. This study aims to evaluate LAMP-SNP assay for C580Y mutation detection by introducing an extra mismatched nucleotide at the 3' end of the FIP primer. The LAMP-SNP assay was performed in a water bath held at a temperature of 56℃ for 45 min. LAMP-SNP products were interpreted by both gel-electrophoresis and HNB-visualized changes in color. The method was then tested with 120 P. falciparum DNA from dried blood spot samples. In comparing the LAMP-SNP assay results with those from DNA sequencing of the clinical samples, the 2 results fully agreed to detect C580Y. The sensitivity and specificity of the LAMP-SNP assay showed 100%. There were no cross-reactions with other Plasmodium species and other Pfkelch13 mutations. The LAMP-SNP assay performed in this study was rapid, reliable, and useful in detecting artemisinin resistance in the field study.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.2
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• pp.150-155
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• 2014

The measurement of $17{\alpha}$-hydroxyprogesterone ($17{\alpha}$-OHP) in a dried blood spot on filter paper is an important for screening of congenital adrenal hyperplasia (CAH). Since high levels of $17{\alpha}$-OHP are frequently observed in premature infants without congenital adrenal hyperplasia, we evaluated cuts-off based on birth weight and performed validation. Birth weight and $17{\alpha}$-OHP concentration data of 292,204 newborn screening subjects in Greencross labopratories were analyzed. The cut-off values based on birth weight were newly evaluated and validated with the original data. The mean $17{\alpha}$-OHP concentration were 7.25 ng/mL in very low birth weight (VLBW) group, 4.02 ng/mL in low birth weight (LBW) group, 2.53 g/mL in normal birth weight (NBW) group, and 2.24 ng/mL in heavy birth weight (HBW) group. The cut-offs for CAH were decided as follows: 21.12 ng/mL for VLBW and LBW groups and 11.14 ng/mL for NBW and HBW groups. When applied new cut-offs for original data, positive rates in VLBW and LBW groups were decreased and positive rates in NBW and HBW groups were increased. The cut-offs based on birth weight should be used in the screening for CAH. We believe that our new cut-off reduce the false positive rate and false negative rate and our experience for cut-off set up and validation will be helpful for other laboratories doing newborn screening test.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.3 no.1
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• pp.86-93
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• 2003

Background : The SCL began screening of newborns and high risk group blood spots with tandem mass spectrometry (MS/MS) in April 2001. Our goal was to determine approximate prevalence of metabolic disorders, optimization of decision criteria for estimation of preventive effect with early diagnosis. This report describes the ongoing effort to identify more than 30 metabolic disorders by MS/MS in South Korea. Methods : Blood spot was collected from day 2 to 30 (mostly from day 2 to 10) after birth for newborn. Blood spot of high risk group was from the pediatric patients in NICU, developmental delay, mental retardation, strong family history of metabolic disorders. One punch (3.2 mm ID) of dried blood spots was extracted with $150{\mu}L$ of methanol containing isotopically labelled amino acids (AA) and acylcarnitines (AC) internal standards. Butanolic HCl was added and incubated at $65^{\circ}C$ for 15 min. The butylated extract was introduced into the inlet of MS/MS. Neutral loss of m/z 102 and parent ion mode of m/z 85 were set for the analyses of AA and AC, respectively. Diagnosis was confirmed by repeating acylcarnitine profile, urine organic acid and plasma amino acid analysis, direct enzyme assay, or molecular testing. Results : Approximately 31,000 neonates and children were screened and the estimated prevalence (newborn/high risk group), sensitivity, specificity and recall rate amounted to 1:2384/1:2066, 96.55%, 99.98%, and 0.73%, respectively. Confirmed 28 (0.09%) multiple metabolic disorders (newborn/high risk) were as follows; 13 amino acid disorders [classical PKU (3/4), BH4 deficient-hyperphenylalaninemia (0/1), Citrullinemia (1/0), Homocystinuria (0/2), Hypermethioninemia (0/1), Tyrosinemia (1/0)], 8 organic acidurias [Propionic aciduria (2/1), Methylmalonic aciduria (0/1), Isovaleric aciduria (1/1), 3-methylcrotonylglycineuria (1/0), Glutaric aciduria type1 (1/0)], 7 fatty acid oxidation disorders [LCHAD def. (2/2), Mitochondrial TFP def. (0/1), VLCAD def. (1/0), LC3KT def. (0/1). Conclnsion : The relatively normal development of 10 patients with metabolic disorders among newborns (except for the expired) demonstrates the usefulness of newborn screening by MS/MS for early diagnosis and medical intervention. However, close coordination between the MS/MS screening laboratory and the metabolic clinic/biochmical geneticists is needed to determine proper decision of screening parameters, confirmation diagnosis, follow-up scheme and additional tests.

• Biomedical Science Letters
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• v.15 no.3
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• pp.229-232
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• 2009

DNA isolation for PCR-based short tandem repeat (STR) analysis is essential to recover high yields of amplifiable DNA from low copy number (LCN) DNA samples. There are different methods developed for DNA extraction from the small bloodstain and gloves, commonly found at crime scenes. In order to obtain STR profiles from LCN DNA samples, DNA extraction protocols, namely the automated $iPrep^{TM}$ $ChargeSwitch^{(R)}$ method, the automated $QIAcube^{TM}$ method, the automated $Maxwell^{(R)}$ 16 DNA $IQ^{TM}$ Resin method, and the manual $QIAamp^{(R)}$ DNA Micro Kit method, were evaluated. Extracted DNA was quantified by the $Quantifiler^{TM}$ Human DNA Quantification Kit and DNA profiled by $AmpFISTR^{(R)}$ $Identifiler^{(R)}$ Kit. Results were compared based on the amount of DNA obtained and the completeness of the STR profiles produced. The automated $iPrep^{TM}$ $ChargeSwitch^{(R)}$ and $QIAcube^{TM}$ methoas produced reproducible DNA of sufficient quantity and quality trom the dried blood spot. This two automated methods showed a quantity and quality comparable to those of the forensic manual standard protocols normally used in our laboratory. In our hands, the automated DNA extraction method is another obvious choice when the forensic case sample available is bloodstain. The findings of this study indicate that the manual simple modified $QIAamp^{(R)}$ DNA Micro Kit method is best method to recover high yields of amplifiable DNA from the numerous potential sources of LCN DNA samples.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.43-49
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• 2015

The aim of the study was to explore the possible molecular markers of chloroquine resistance in Plasmodium vivax isolates in Thailand. A total of 30 P. vivax isolates were collected from a malaria endemic area along the Thai-Myanmar border in Mae Sot district of Thailand. Dried blood spot samples were collected for analysis of Pvmdr1 and Pvcrt-o polymorphisms. Blood samples ($100{\mu}l$) were collected by finger-prick for in vitro chloroquine susceptibility testing by schizont maturation inhibition assay. Based on the cut-off $IC_{50}$ of 100 nM, 19 (63.3%) isolates were classified as chloroquine resistant P. vivax isolates. Seven non-synonymous mutations and 2 synonymous were identified in Pvmdr1 gene. Y976F and F1076L mutations were detected in 7 (23.3%) and 16 isolates (53.3%), respectively. Analysis of Pvcrt-o gene revealed that all isolates were wild-type. Our results suggest that chloroquine resistance gene is now spreading in this area. Monitoring of chloroquine resistant molecular markers provide a useful tool for future control of P. vivax malaria.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.6 no.1
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• pp.96-107
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• 2006

Citrin deficiency resulting from mutations of SLC25A13is associated with two major clinical phenotypes; neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and adult-onset type 2 citrullinemia (CTLN2). In Korea, 7 cases of citrin deficiency have been diagnosed based on biochemical and molecular findings. Four NICCD cases were identified by newborn screening using MS/MS or presenting symptoms like cholestatic jaundice. They are all males, presenting with conjugated hyperbilirubinemia, elevated liver enzymes, hypoalbuminemia, mild hyperammonemia, elevated citrullin, methionine and threonine. All of them have been spontaneously recovered from hepatic manifestation by the age of 6-8 months. Mutation analysis has been performed using their genomic & cDNAs obtained from skin fibroblasts. They turned out to be compound heterozygotes carrying each of 851del4, IVS11+1G>A, and IVS13+1G>A. Three CTLN2 patients were identified. Two adult male patients presented with a sudden loss of consciousness, seizure, vomiting, hyperammonemia and citrullinemia in their twenties. They carried an IVS13+1G>A, 851del4, and IVS11+1G>A mutant alleles. The other CTLN2 patient was 52 year old female patient, manifesting lethargy, altered consciousness, irritability and hyperammonemia. Similar clinical symptoms had recurred at the delivery of first and second babies in her past medical history. She was managed by hemodialysis and survived with neurological sequellae. Also, we screened the presence of 9 common mutations in 500 Korean newborns using dried blood spot of filter papers. Only a allele carried 854del4 mutation. In conclusion, the entire picture of citrin deficiency in Korea including incidence, genotype, clinical features and natural courses, is still vague at the present time.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.20 no.4
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• pp.263-267
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• 2017

Patients with lysosomal acid lipase (LAL) deficiency and glycogen storage disease (GSD) demonstrated hepatomegaly and dyslipidemia. In our case, a 6-year-old boy presented with hepatosplenomegaly. At 3 years of age, GSD had been diagnosed by liver biopsy at another hospital. He showed elevated serum liver enzymes and dyslipidemia. Liver biopsy revealed diffuse microvesicular fatty changes in hepatocytes, septal fibrosis and foamy macrophages. Ultrastructural examination demonstrated numerous lysosomes that contained lipid material and intracytoplasmic cholesterol clefts. A dried blood spot test revealed markedly decreased activity of LAL. LIPA gene sequencing identified the presence of a novel homozygous mutation (p.Thr177Ile). The patient's elevated liver enzymes and dyslipidemia improved with enzyme replacement therapy. This is the first report of a Korean child with LAL deficiency, and our findings suggest that this condition should be considered in the differential diagnosis of children with hepatosplenomegaly and dyslipidemia.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.2
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• pp.35-42
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• 2018

Purpose: To follow up Korean patients with metabolic and endocrine disorders ascertained by Korea Genetics Research Center, and assess the long-term effectiveness of extended newborn screening program in Korea. Methods: From January 2000 to December 2017, tandem mass spectrometry and fluoroimmunoassay were employed in extended newborn screening (NBS). The NBS program obtained dried blood spots from 283,626 babies, 48 hours after birth, and screened for galactosemia, congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), and 50 preventable inborn errors of amino acid, fatty acid, and organic acid metabolism. Results: 28 cases of amino acid disorders, 75 cases of organic acid disorders, 27 cases of fatty acid disorders, 51 cases of urea cycle disorders, 127 cases of CH, 14 cases of CAH, and 15 cases of galactosemia were ascertained through NBS and subsequent confirmatory laboratory tests. Patients with amino acid metabolic disorders, galactosemia, CH, or CAH were more likely to have a better long-term outcome if detected early. Early management of MSUD led to much better outcome in over 90%. Despite early intervention, 32% of other organic acidemia cases still resulted in developmental delay and neurological problems. Fatty acid disorders showed varied results; those with EMA and MCAD had a good outcome, but those with VLCAD had serious neurological problems and considerably higher mortality. 75% with UCD experienced serious neurological complications and higher mortality. Conclusion: The nation-wide NBS program must be accompanied by comprehensive long-term management and physician and family education of inborn errors of metabolism for a better outcome.