Objective Narcolepsy type 1 （NT1） is known to be associated with low levels of hypocretin-1 （Hcrt-1） in cerebrospinal fluid （CSF）. The standard method for Hcrt-1 measurement is radioimmunoassay （RIA） with imported reagents， but this antibody-dependent method is limited to radiation safety-certified lab， gradual radioactivity degradation， and slow turn-around time. The purpose of this study is to explore a non-radioactive， faster， and antibody independent domestic method in China for Hcrt-1 detection. Methods Repeated testing of cerebrospinal fluid from 14 clinically diagnosed NT1 patients and 10 non-narcolepsy patients was performed using liquid chromatography-tandem mass spectrometry （LC-MS/MS）technology，including the establishment and optimization of fundamental methodological procedures. The main steps involved the addition of non-radioactive isotope-labeled internal standards to the cerebrospinal fluid， followed by solid-phase extraction， mass spectrometry signal acquisition， and quantitative analysis. The results were then compared with the corresponding radioimmunoassay（RIA） findings. Results The LC-MS/MS method showed faster speed， and good linearity across a wider range of synthesized standard（5~2 500 pg/ml）， and good repeatability. Although this absolute-quantitation-based LC-MS/MS method and RIA method have different reading values in Hcrt-1 quantitation， they both can segregate NT1 group from non-NT1 group well. Conclusion Although larger cohorts are needed to set up a standard method in China，LC-MS/MS method is proved to be an easier， safer， faster， and possibly more accurate method for Hcrt-1 quantitation and detection for NT1 diagnosis.
Narcolepsy ; Radioimmunoassay

Anhidrotic ectodermal dysplasia (AED) is a rare hereditary disorder with a triad of sparse hair, dental hypoplasia, and anhidrosis. Here we report a case of AED with food allergy and atopic eczema. The patient was a 11-month-old boy admitted to our hospital with pyrexia for 2 weeks. He presented with a history of dry skin, eczema, and food allergy to egg. On clinical examination, his body temperature was 38.8°C, with dry skin and eczema almost all over the body, sparse eyebrows, and scalp hair. Laboratory investigations and physical examination did not show any evidence of infection. Radioallergosorbent test was positive to egg yolk, egg white, ovomucoid, milk, house dust, and house dust mite. As the child did not sweat despite the high fever, we performed the sweat test which revealed a total lack of sweat glands. Genetic examination revealed a mutation of the EDA gene and he was diagnosed as AED. His pyrexia improved upon cooling with ice and fan. His mother had lost 8 teeth and her sweat test demonstrated low sweating, suggestive of her being a carrier of AED. Atopy and immune deficiencies have been shown to have a higher prevalence in patients with AED. Disruption of the skin barrier in patients with AED make them more prone to allergic diseases such as atopic eczema, bronchial asthma, allergic rhinitis and food allergy. Careful assessment of the familial history is essential to differentiate AED when examining patients with pyrexia of unknown origin and comorbid allergic diseases.
Asthma ; Body Temperature ; Child ; Dermatitis, Atopic ; Dust ; Ectodermal Dysplasia ; Eczema ; Egg White ; Egg Yolk ; Eyebrows ; Fever ; Food Hypersensitivity ; Hair ; Humans ; Hypohidrosis ; Ice ; Infant ; Male ; Milk ; Mothers ; Ovomucin ; Ovum ; Physical Examination ; Prevalence ; Pyroglyphidae ; Radioallergosorbent Test ; Rhinitis, Allergic ; Scalp ; Skin ; Sweat ; Sweat Glands ; Sweating ; Tooth

BACKGROUND: The prevalence of allergy among Surabaya school children is currently unknown. OBJECTIVE: To identify the prevalence of the common allergic sensitization and allergic diseases among school children and undergraduate students in suburban of Surabaya by epidemiologic data collection. METHODS: A multistage simple random sampling was done to select 5 primary schools, 8 secondary schools (4 of junior high schools and senior high schools, respectively), and 1 university from 5 districts in Surabaya city. Out of 550 invited respondents, 499 (128 primary school, 221 secondary school, and 150 undergraduate) respondents gave their consent. A complete personal history, allergic symptoms, environmental exposure of common allergens was obtained from interview and the physical examinations were performed. Skin prick test (SPT) was done using 45 different allergen extracts. Total serum IgE and specific IgE radioallergosorbent test levels were measured for respondents with allergic manifestations. RESULTS: There was an increasing SPT positivity among study respondents, from primary school, secondary school, to undergraduate students (21.90%, 28.95%, to 45.30% respectively). Cockroach (42.85%) and fungi/mold spore (42.85%) were the most common allergens in primary school children. House dust mites was the most common allergen in secondary school (63.16%) and undergraduate students (58.82%). Urticaria and rhinitis were the commonest allergic diseases manifestation. History of atopy was positive in 60.79% of the allergic respondents. CONCLUSION: The prevalence of allergic sensitization among school children and undergraduate students in Surabaya suburb areas were increased compared to previous estimates in 1998. While house dust mites are known as important allergens, surprisingly cockroach was the common allergen among the younger school children.
Allergens ; Child ; Cockroaches ; Data Collection ; Developed Countries ; Environmental Exposure ; Epidemiologic Studies ; Humans ; Hypersensitivity ; Immunoglobulin E ; Indonesia ; Physical Examination ; Prevalence ; Pyroglyphidae ; Radioallergosorbent Test ; Rhinitis ; Skin ; Spores ; Surveys and Questionnaires ; Urticaria

BACKGROUND/AIMS: Infliximab (IFX) often loses its therapeutic effect in initial responders with inflammatory bowel disease (IBD) over time. Low serum IFX trough levels (TLs) are linked to poor clinical response and outcomes. Maintenance of optimal therapeutic IFX concentrations is important for sustaining response and achieving good clinical outcomes. Measurement of serum IFX TLs is helpful for determining a further proper therapeutic plan. However, adequate therapeutic IFX TLs in pediatric IBD is uncertain. We aimed to identify the cutoff values for IFX TLs associated with laboratory response to IFX maintenance therapy. METHODS: Patients with pediatric IBD who had received IFX infusions between December 2008 and March 2015 at Samsung Medical Center were retrospectively investigated. We analyzed 239 blood samples that were collected from 103 pediatric patients. We measured IFX TLs at induction (6 and 14 weeks) and during maintenance therapy (>22 weeks, 8 weeks interval) by fluid-phase radioimmunoassays. RESULTS: A significant association was found between the erythrocyte sedimentation rate (ESR) and IFX TLs during maintenance (correlation coefficient, −0.11; p=0.0005). A cutoff value of 18 mm/hr for ESR was used to define higher levels. Receiver operating characteristic analysis identified optimal cutoff values: IFX TL >1.58 μg/mL (sensitivity 82% and specificity 73%). CONCLUSIONS: Cutoff values are considered a prerequisite for further investigating the clinical usefulness of measurements of IFX in patients maintained with IFX treatment.
Blood Sedimentation ; Drug Monitoring ; Humans ; Inflammatory Bowel Diseases ; Infliximab ; Radioimmunoassay ; Retrospective Studies ; ROC Curve ; Sensitivity and Specificity

BACKGROUND/AIMS: The aim of this study was to determine the risk factors of multiple gastric polyps according to the histological classification of gastric polyps.METHODS: Subjects with multiple gastric polyps (at least three) during endoscopy were enrolled prospectively. They were assigned to a fundic gland polyp (FGP) group and hyperplastic polyp (HP) group based on a histological classification of gastric polyps. Helicobacter pylori (H. pylori) was confirmed by its histology. Serum gastrin was measured using the radioimmunoassay method. A questionnaire was taken regarding the intake of proton pump inhibitor and nonsteroidal anti-inflammatory drugs, alcohol, smoking history, and diet.RESULTS: Among the 60 subjects enrolled from 2015 to 2018 at Seoul National University Bungdang Hospital, 47 and 13 subjects were assigned to the FGP and HP groups, respectively. The H. pylori infection rate was 12.8% in the FGP group, which is lower than that in the HP group (69.2%, p<0.001). The gastrin level was higher in the HP group (194.7 pg/dL, range 50.6–387.8 pg/dL) than in the FGP group (57.4 pg/dL, range 24.8–79.0 pg/dL) (p=0.007). Histologically, neutrophil infiltration in the antrum and body of the stomach were higher in the HP group than in the FGP group (p=0.022 and p=0.030, respectively). In contrast, monocyte infiltration in the antrum and body of the stomach were higher in the FGP group than in the HP group (p=0.018 and p<0.001, respectively).CONCLUSIONS: HPs arise from inflammation caused by H. pylori. On the other hand, the FGP was not associated with H. pylori or environmental factors.
Classification ; Cohort Studies ; Diet ; Endoscopy ; Gastrins ; Hand ; Helicobacter pylori ; Inflammation ; Methods ; Monocytes ; Neutrophil Infiltration ; Polyps ; Prospective Studies ; Proton Pump Inhibitors ; Proton Pumps ; Radioimmunoassay ; Risk Factors ; Seoul ; Smoke ; Smoking ; Stomach

BACKGROUND: In both developed and developing countries, noise is regarded as the most common occupational hazard in various industries. The present study aimed to examine the effect of sound pressure level (SPL) on serum cortisol concentration in three different times during the night shift. METHODS: This case–control study was conducted among 75 workers of an industrial and mining firm in 2017. The participants were assigned to one of the three groups (one control and two case groups), with an equal number of workers (25 participants) in each group. Following the ISO 9612 standard, dosimetry was adopted to evaluate equivalent SPL using a TES-1345 dosimeter. The influence of SPL on serum cortisol concentration was measured during the night shift. The serum cortisol concentration was measured using a radioimmunoassay (RIA) test in the laboratory. Repeated measure analysis of variance and linear mixed models were used with α = 0.05. RESULTS: The results indicated a downward trend in the serum cortisol concentration of the three groups during the night shift. Both SPL and exposure time significantly affected cortisol concentration (p < 0.0001, p < 0.0001). Conversely, age and body mass index had no significant influence on cortisol concentration (p = 0.360, p = 0.62). CONCLUSION: Based on the obtained results, increasing SPL will lead to enhancement of serum cortisol concentration. Given that cortisol concentration varies while workers are exposed to different SPLs, this hormone can be used as a biomarker to study the effect of noise-induced stress.
Body Mass Index ; Developing Countries ; Hydrocortisone ; Mining ; Noise ; Noise, Occupational ; Radioimmunoassay

BACKGROUND/AIMS: The aim of this study was to determine the risk factors of multiple gastric polyps according to the histological classification of gastric polyps. METHODS: Subjects with multiple gastric polyps (at least three) during endoscopy were enrolled prospectively. They were assigned to a fundic gland polyp (FGP) group and hyperplastic polyp (HP) group based on a histological classification of gastric polyps. Helicobacter pylori (H. pylori) was confirmed by its histology. Serum gastrin was measured using the radioimmunoassay method. A questionnaire was taken regarding the intake of proton pump inhibitor and nonsteroidal anti-inflammatory drugs, alcohol, smoking history, and diet. RESULTS: Among the 60 subjects enrolled from 2015 to 2018 at Seoul National University Bungdang Hospital, 47 and 13 subjects were assigned to the FGP and HP groups, respectively. The H. pylori infection rate was 12.8% in the FGP group, which is lower than that in the HP group (69.2%, p<0.001). The gastrin level was higher in the HP group (194.7 pg/dL, range 50.6–387.8 pg/dL) than in the FGP group (57.4 pg/dL, range 24.8–79.0 pg/dL) (p=0.007). Histologically, neutrophil infiltration in the antrum and body of the stomach were higher in the HP group than in the FGP group (p=0.022 and p=0.030, respectively). In contrast, monocyte infiltration in the antrum and body of the stomach were higher in the FGP group than in the HP group (p=0.018 and p<0.001, respectively). CONCLUSIONS: HPs arise from inflammation caused by H. pylori. On the other hand, the FGP was not associated with H. pylori or environmental factors.
Classification ; Cohort Studies ; Diet ; Endoscopy ; Gastrins ; Hand ; Helicobacter pylori ; Inflammation ; Methods ; Monocytes ; Neutrophil Infiltration ; Polyps ; Prospective Studies ; Proton Pump Inhibitors ; Proton Pumps ; Radioimmunoassay ; Risk Factors ; Seoul ; Smoke ; Smoking ; Stomach

PURPOSE: In radioimmunoassay (RIA), the gamma counter is the important instrument for the accurate measurement. To manage quality assurance of RIA, the counting efficiency of gamma counter is one of the important parameters. The aimof this study was to evaluate the counting efficiency of gamma counters in multiple institutes on the base of traceability by using the certified reference materials (CRMs).METHODS: Twenty-three institutes that perform RIA were enrolled in this study. I-125 CRMs that were certified by National Institute of Standards and Technology (NIST) were used. Each institute was asked to count the activity of I-125 CRMs at most twice on all gamma counters in use. The counting efficiency of each well of counter was calculated on the base of NIST-certified information, corrected for I-125 decay for date of testing.RESULTS: From 23 institutes, 44 gamma counters were evaluated. The average counting efficiency of all wells was 85.9% and the standard deviation was 13.5%. As a mean value of each gamma counter, three gamma counters showed poor counting efficiency (less than 70%). The poorest counting efficiency was 7%. The counting efficiency of seven gamma counters was between 70 and 75%. Eight counters had the counting efficiency between 75 and 90%. More than half of counter (26 gamma counters) showed excellent counting efficiency (more than 90%). The standard deviation variation range of inter-well efficiency was from 0 to 11.2.CONCLUSION: The first survey on the counting efficiency of gamma counter was performed in South Korea. Most of the RIA laboratories have well managed the quality assurance of gamma counter.
Academies and Institutes ; Immunoradiometric Assay ; Korea ; Quality Control ; Radioimmunoassay

BACKGROUND/AIMS: Maternal thyroid dysfunction has been associated with adverse pregnancy outcomes. The purpose of our study was to establish trimester-specific reference intervals for thyroid hormones in pregnant women in Korea, where iodine intake is more than adequate and to examine pregnancy and perinatal outcomes in their offspring. METHODS: Among 459 healthy pregnant women who were screened, we enrolled 417 subjects who had negative results for thyroid autoantibodies. Serum thyroid stimulating hormone (TSH) and free thyroxine were measured using an immunoradiometric assay. Urine iodine concentration was measured using inductively coupled plasma-mass spectrometry in 275 women. Reference ranges of thyroid hormones were determined according to the guidelines of the National Academy of Clinical Biochemistry. Pregnancy and perinatal outcomes were compared according to maternal thyroid function. RESULTS: The reference ranges of serum TSH were 0.03 to 4.24 mIU/L in the first trimester, 0.13 to 4.84 mIU/L in the second trimester, and 0.30 to 5.57 mIU/L in the third trimester. Pregnancy and perinatal outcomes did not vary in mothers with subtle changes in thyroid function. CONCLUSIONS: Trimester-specific thyroid hormone reference intervals in Korean pregnant women differ from those of other countries with different iodine nutrition status and ethnicity. The establishment of population-based, reliable trimester-specific reference intervals is critical for the interpretation of thyroid function in pregnant women to avoid unnecessary tests and treatments.
Autoantibodies ; Biochemistry ; Female ; Humans ; Immunoradiometric Assay ; Iodine ; Korea* ; Mothers ; Nutritional Status ; Pregnancy Outcome ; Pregnancy Trimester, First ; Pregnancy Trimester, Second ; Pregnancy Trimester, Third ; Pregnancy* ; Pregnant Women ; Reference Values ; Republic of Korea ; Spectrum Analysis ; Thyroid Gland* ; Thyroid Hormones* ; Thyrotropin ; Thyroxine

The major apple allergen Mal d 1 cross-reacts with the homologous birch pollen allergen Bet v 1 and causes immunoglobulin E (IgE)-mediated immediate-type allergic reactions. In some patients, delayed-type hypersensitivity to apples may develop within 72 hours without evidence of specific IgE or a positive skin prick test (SPT). The aim of the study was to evaluate the concomitance of delayed-type hypersensitivity reactions and immediate IgE-mediated reactions against high- and low-allergenic apple cultivars in patients with birch pollen allergy. Data were obtained from 45 adults with clinical symptoms of birch pollen allergy. Patients were exposed to apple pulp via atopy patch tests (APTs) and SPTs. Levels of IgE specific to Bet v 1 and Mal d 1 were measured with a radioallergosorbent test. Patients allergic to birch pollen showed the highest rate of positive SPT responses to Golden Delicious apples and the lowest rate to low-allergenic cultivar Grey French Reinette. Among these patients, 9% developed delayed hypersensitivity reactions to either Golden Delicious or Grey French Reinette apples; these reactions manifested clinically as erythema with papules (class ++). Fifty percent of APT-positive patients were concomitantly SPT-negative. Here, we show for the first time the clinical relevance of T cell-driven allergic reactions to apples. APTs may reveal type IV sensitization in patients who are negative for the corresponding type I sensitization tests. Thus, utilization of the APT procedure with fresh apple appears to be a valuable tool for the diagnosis of apple allergy and may improve the accuracy of food allergy diagnoses.
Adult ; Betula* ; Diagnosis ; Erythema ; Food Hypersensitivity ; Humans ; Hypersensitivity* ; Hypersensitivity, Delayed ; Immunoglobulin E ; Immunoglobulins ; Incidence* ; Malus* ; Patch Tests ; Pollen* ; Radioallergosorbent Test ; Rhinitis, Allergic, Seasonal ; Skin