Accurate interpretation of elevated amylase levels is essential, especially for patients presenting with an overlapping pancreatic or liver disease or for patients with a history of these diseases [1]. In this study, we have described an unusual case of macroamylasemia that occurred immediately after acute pancreatitis. On March 9, 2010, a 56-yr-old Korean man was admitted to the emergency department because of confusion and delirium. He had previously been hospitalized for 4 months because of alcoholic cirrhosis and had been discharged 5 days prior to this admission. During the 4-month hospitalization, he had received treatment for esophageal variceal bleeding and acute pancreatitis. At that time, his serum amylase levels and lipase levels were 1,171 U/L and 298 U/L, respectively. Abdominal computed tomography images showed mild swelling of the pancreas and a cystic lesion (1.5 cm) in the pancreatic head (Fig. 1). The patient received therapy for acute pancreatitis. Although he showed improvement in symptoms and radiological findings at the time of discharge, on March 4, 2010, the serum amylase levels had increased to 1,882 U/L (Fig. 2). Five days later, the patient was readmitted because of altered mental status. Physical examinations revealed no abdominal pain and no rebound tenderness. The results of the blood biochemistry tests were as follows: total protein, 9.2 g/dL; albumin, 2.9 g/dL; amylase, 2,232 IU/L (25-125 IU/L); lipase, 61 IU/L (5.5-58 IU/L); total bilirubin, 2.39 mg/dL; direct bilirubin, 1.63 mg/dL; AST, 48 IU/L; ALT, 30 IU/L; alkaline phosphatase (ALP), 64 IU/L; gamma-glutamyl transpeptidase (GGT), 29 IU/L; and ammonia, 141 mg/dL. The serological tests yielded the following results: IgG, 3,850 mg/dL (700-1,600 mg/dL) and IgA, 664 mg/dL (70-400 mg/dL). After readmission, the urine amylase level was 54 IU/L (1-352 IU/L), and the amylase-creatinine clearance ratio (ACCR) was calculated to be 0.07%. Macroamylasemia was diagnosed on the basis of these findings. Serum amylase isoenzyme electrophoresis showed that the proportions of P-type and S-type amylases were 75.3% and 24.7%, respectively. Capillary serum protein electrophoresis revealed polyclonal gammopathy with a beta-gamma bridge pattern, which is a typical pattern in liver cirrhosis (Fig. 3). The patient's mental status returned to normal, and he is still in the hospital for continued management of liver cirrhosis. Fig. 1 Findings of abdominal computed tomography performed when the patient showed acute pancreatitis. A cystic lesion (arrows, 1.5 cm) in the pancreatic head region (A) and mild swelling of the pancreas (B) are observed. Fig. 2 Trends in the serum amylase and lipase levels from the time of diagnosis of acute pancreatitis (*) to the time of diagnosis of macroamylasemia (**). Serum amylase levels are high for about 4 months, while lipase levels fall near the upper reference limit. ... Fig. 3 Serum amylase isoenzyme electrophoresis (A) and capillary electrophoresis (B and C). (A) The P-type amylase level increased to 1,664.13 IU/L (75.30% of the total amylase concentration). The S-type amylase level is within the reference interval (545.87 ... Macroamylasemia has been reported in 2.5% of the patients with hyperamylasemia and in 1% of the general population; approximately 0.4% of the cases in the general population occur in the West [2, 3]. Increased amylase and/or lipase activities were seen in 8% of the patients without pancreatic diseases [4]. In the previous reports, macroamylasemia was mainly reported in patients with disturbed humoral immunity, such as those with celiac disease, multiple myeloma, HIV infection, ulcerative colitis, and rheumatoid arthritis [2, 3, 5-8]. One of the predisposing conditions for macroamylasemia is a polyclonal increase in immunoglobulins (Ig). Some studies have reported that macroamylasemia may decrease or resolve when these underlying diseases are treated, and that the risk for autoimmune or lymphoproliferative diseases is higher in macroamylasemia with light-chain restriction in Ig-enzyme complexes [2, 9]. Complex formation with IgA-type immunoglobulins was reported in 92% of the patients with macroamylasemia [2, 9]. Liver cirrhosis is known to be a condition that increases IgA production through the following mechanism: Serum albumin concentrations are greatly reduced by increased albumin degradation as well as decreased synthesis. To maintain plasma oncotic pressure, the shortage in albumin is compensated by a polyclonal increase in Igs. This polyclonal gammopathy involves all Igs such that an increase of IgA in the beta region shows beta-gamma bridging [10]. Although there is no information on the Ig subtypes that are involved in the formation of macroamylase, polyclonal gammopathy might contribute to an increased propensity between amylase and Ig to form macroenzymes. The latent period for the clinical appearance of macroamylasemia varies from several weeks to months [2]. Hyperamylasemia persisted in our patient even though the symptoms and radiological findings of acute pancreatitis showed clinical improvement. Therefore, although macroamylasemia was diagnosed only a few weeks prior to presentation, it persisted even after the resolution of acute pancreatitis. To avoid unnecessary laboratory tests, misdiagnosis, and overtreatment, it is essential to differentiate macroamylasemia from hyperamylasemia, particularly in patients without corroborating clinical evidence for hyperamylasemia. Therefore, we suggest that patients with macroamylasemia of unknown origin should be carefully assessed since they may have an underlying condition characterized by Ig overproduction even though they may present with persistent hyperamylasemia.
Background: Measurement uncertainty characterizes the dispersion of the quantity values attributed to a measurand.Although this concept was introduced to medical laboratories some years ago, not all medical researchers are familiar with it.Therefore, the evaluation and expression of measurement uncertainty must be highlighted using a practical example.Methods: In accordance with the procedure for evaluating and expressing uncertainty, provided by the Joint Committee for Guides in Metrology (JCGM), we used plasma glucose (Glu) as an example and defined it as the measurand.We then analyzed the main sources of uncertainty, evaluated each component of uncertainty, and calculated the combined uncertainty and expanded uncertainty with 2 budgets for single measurements and continuous monitoring, respectively.Results: During the measurement of Glu, the main sources of uncertainty included imprecision, within-subject biological variance (BVw), calibrator uncertainty, and systematic bias.We evaluated the uncertainty of each component to be 1.26%, 1.91%, 5.70%, 0.42%, and -2.87% for within-run imprecision, between-day imprecision, BVw, calibrator uncertainty, and systematic bias, respectively.For a single specimen, the expanded uncertainty was 7.38% or 6.1±0.45mmol/L (κ=2); in continuous monitoring of Glu, the expanded uncertainty was 13.58% or 6.1±0.83mmol/L (κ=2).Conclusions: We have demonstrated the overall procedure for evaluating and reporting uncertainty with 2 different budgets.The uncertainty is not only related to the medical laboratory in which the measurement is undertaken, but is also associated with the calibrator uncertainty and the biological variation of the subject.Therefore, it is helpful in explaining the accuracy of test results.
Amyloidosis is a heterogeneous group of diseases in which misfolding of extracellular proteins is the pathogenic factor. Light chain amyloidosis (AL) is the most common form of amyloidosis, and the causative proteins in AL are the immunoglobulin light chains produced by clonal plasma cells. Hemorrhagic events, ranging from mild subcutaneous hemorrhage to life-threatening bleeding, account for a significant proportion of morbidities and mortality in AL patients. Deficiency of factor X from deposition into amyloid fibrils has been reported to be the most common acquired factor deficiency in AL. We herein report 2 patients with acquired factor X deficiency in AL. A 55-yr-old woman with AL had a prolonged prothrombin time (PT) and an activated partial thromboplastin time (aPTT) of 2.51 International Normalized Ratio (INR) and 75.1 sec, respectively, which were corrected on mixing with normal plasma. Factor X activity was markedly decreased at 5%. The other patient was a 67-yr-old man with AL with a PT of 1.63 INR and an aPTT of 50.3 sec, which were corrected on mixing with normal plasma. Factor X activity was decreased at 17%. Neither of the patients had apparent hemorrhagic manifestations. Identification of acquired factor deficiency and timely coagulation tests are needed in the diagnostic workup and management in AL.
Better biomarkers are urgently needed to cancer detection, diagnosis, and prognosis. While the genomics community is making significant advances in understanding the molecular basis of disease, proteomics will delineate the functional units of a cell, proteins and their intricate interaction network and signaling pathways for the underlying disease. Great progress has been made to characterize thousands of proteins qualitatively and quantitatively in complex biological systems by utilizing multi-dimensional sample fractionation strategies, mass spectrometry and protein microarrays. Comparative/quantitative analysis of high-quality clinical biospecimen (e.g., tissue and biofluids) of human cancer proteome landscape has the potential to reveal protein/peptide biomarkers responsible for this disease by means of their altered levels of expression, post-translational modifications as well as different forms of protein variants. Despite technological advances in proteomics, major hurdles still exist in every step of the biomarker development pipeline. The National Cancer Institute's Clinical Proteomic Technologies for Cancer initiative (NCI-CPTC) has taken a critical step to close the gap between biomarker discovery and qualification by introducing a pre-clinical "verification" stage in the pipeline, partnering with clinical laboratory organizations to develop and implement common standards, and developing regulatory science documents with the US Food and Drug Administration to educate the proteomics community on analytical evaluation requirements for multiplex assays in order to ensure the safety and effectiveness of these tests for their intended use.
Central nervous system (CNS) involvement in acute promyelocytic leukemia (APL) is rare, and the presence of CNS symptoms at the time of diagnosis of APL is even rarer. We report 2 cases of APL presenting with CNS involvement. A 43-yr-old woman presented with easy bruising and stuporous mentality. Her complete blood count (CBC) revealed leukocytosis with increased blasts. Bone marrow (BM) analysis was carried out, and the diagnosis of APL was confirmed. This was done by cytogenetic analysis and demonstration of PML-RARα rearrangement by reverse transcriptase PCR in the BM cells. A lumbar puncture was performed to investigate the cause of her stuporous mentality, and her cerebrospinal fluid (CSF) analysis revealed 97% leukemic promyelocytes. Despite systemic and CNS therapy, she died due to septic shock by infection and rapid disease progression only 3 days after her admission. Another patient, a 3-yr-old girl, presented with easy bruising and epistaxis, and her CBC showed pancytopenia with increased blasts. BM studies confirmed APL. Quantitative PCR for PML-RARα in the BM cells revealed a PML-RARα/ABL ratio of 0.33 and CSF analysis revealed 9.5% leukemic promyelocytes (2 of 21 cells). She received induction chemotherapy and intrathecal therapy and achieved complete remission (CR) in the BM and CNS. She has been maintained in the CR status for the past 31 months. Thus, patients with APL must be evaluated for CNS involvement if any neurological symptoms are present at the time of diagnosis.
Background: Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction caused by antibodies to the heparin/platelet factor 4 (PF4) complex, resulting in thrombocytopenia and prothrombotic state.HIT diagnosis is challenging and depends on clinical presentation and laboratory tests.We investigated the usefulness of clinical scores and heparin/PF4 ELISA optical density (OD) as a diagnostic marker and thrombosis predictor in HIT.Methods: We analyzed 92 patients with suspected HIT.The heparin/PF4 antibody was measured using a commercial ELISA kit (GTI, USA).For each patient, the 4 T's score and Chong's score were calculated.Results: Of the 92 patients, 28 were anti-heparin/PF4-seropositive.The 4 T's score and Chong's score showed good correlation (r =0.874).The 4 T's score and OD values showed good performance for diagnosis of the definite and unlikely HIT groups; however, OD levels showed better sensitivity (93.8%) than the 4 T's score used alone (62.5%).Of the 92 patients, 26 developed thrombosis.The OD values were significantly higher in patients with thrombosis than in those without thrombosis (0.52 vs. 0.22, P <0.001).Patients with high OD values (OD>0.4)had an increased risk of thrombosis (adjusted odds ratio 9. 44 [3.35-26.6],P <0.001) and a shorter 250-day thrombosis-free survival (32.1% vs. 54.7%,P =0.012).Conclusions: ELISA OD values in combination with clinical scoring can improve the diagnosis of and thrombosis prediction in HIT.More attention should be paid to the use of clinical scores and OD values as thrombosis predictors in HIT.
BACKGROUND:CD4+CD25+ regulatory T-cells (Tregs) play a critical role in immune responses. We explored the status of Tregs in neoplastic and autoimmune hematologic diseases. We also evaluated the technical aspects of Treg measurement in terms of sample type and detection markers.METHODS:A total of 68 subjects were enrolled: 11 with AML, 8 with MDS, 10 with autoimmune diseases, and 39 controls. Tregs were analyzed in peripheral blood (PB) and bone marrow (BM) samples from each subject. Flow cytometry and the Human Regulatory T cell Staining Kit (eBioscience, USA) for CD4, CD25, and FoxP3 (forkhead box P3) were used.RESULTS:The CD4+CD25(high)/CD4 and CD4+CD25(high)FoxP3+/CD4 populations were significantly correlated (P<0.0001). The AML and high-risk MDS groups had significantly larger CD4+CD25(high)/CD4 and CD4+CD25(high)FoxP3+/CD4 populations in PB than the autoimmune (P=0.007 and 0.012, respectively) and control groups (P=0.004 and 0.006, respectively). Comparable findings were observed in BM. The CD4+CD25(high)FoxP3+/CD4 population was significantly larger in PB than in BM (P=0.0003).CONCLUSIONS:This study provides comparison data for Tregs in AML, MDS, and autoimmune hematologic diseases, and would be helpful for understanding the different immunologic bases of various hematologic diseases. Treg measurement using CD4, CD25, and/or FoxP3 in PB rather than in BM seems to be practical for routine hematologic purposes. Large-scale analysis of the diagnostic role of Treg measurement is needed.
Background We assessed the efficacy of serial interferon-gamma release assays (IGRAs) for the diagnosis of latent tuberculosis infection (LTBI) in patients receiving immunosuppressive agents for treatment of rheumatic diseases in Korea. Methods Of 276 patients who underwent consecutive screening with one of two IGRAs [QuantiFERON-TB Gold or QuantiFERON-TB Gold In-Tube], 66 patients were evaluated by the serial IGRA for detection of LTBI during therapy with immunosuppressive agents. Information on clinical diagnosis, medication, previous TB, blood cell count, tuberculin skin test, and interferon-gamma (IFN-γ) level measured by IGRA was collected. Results Of the 66 patients, the initial IGRA was positive in 24.2%, negative in 65.2%, and indeterminate in 10.6%. Forty-six patients (69.7%) showed consistent IGRA results during follow-up, and 13 patients (19.7%) had consistently positive results. IGRA conversion rate was 12.1% (8/66) and reversion rate was 4.5% (3/66). Conversion of IGRA results was only observed in ankylosing spondylitis patients, and the median interval between the two tests in patients with conversion was 8.5 months. The mean IFN-γ level in the group of patients with consistently positive IGRA results was higher than that in the group with inconsistently positive results, although this trend was not statistically significant (P=0.293). Indeterminate results were observed most frequently in patients with systemic lupus erythematosus. Conclusions In patients receiving immunosuppressive agents, both IGRA conversions and reversions were observed. Serial IGRA testing may not be needed in patients with a positive initial IGRA result showing high IFN-γ levels, because of high consistency in the test results.
BACKGROUND:Single-nucleotide polymorphism (SNP) analysis is a powerful strategy for large-scale molecular population studies examining phylogenetic relationships among bacterial strains. Mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) can be easily digitized to share data among laboratories. This study applied SNP and MIRU-VNTR analyses for molecular strain typing of Mycobacterium tuberculosis isolates collected throughout Korea.METHODS:We studied 102 clinical M. tuberculosis isolates, including 6 paired strains, collected from 11 university hospitals in Korea in 2008 and 2009. SNPs were detected using hairpin primer assays, and then, MIRU-VNTR analysis was performed.RESULTS:Thirty-five SNPs contained polymorphisms that helped differentiate the 96 tested isolates. The isolates were classified into 15 clusters. The Beijing family strains were distributed within closely related clusters in the SNP dendrogram. For MIRU-VNTR analysis, the 96 isolates were divided into 12 groups. The discriminatory index in 8 of these groups (MIRU-10, -23, -26, and -31; ETR-A, -B, -C, and -F) was high (Hunter-Gaston diversity index > 0.6). Unlike the SNP method, MIRU-VNTR analysis did not identify any notable localizations of Beijing or non-Beijing family isolates in specific clusters.CONCLUSIONS:SNP and MIRU-VNTR analyses are surrogate molecular strain-typing methods for M. tuberculosis in Korea where Beijing family isolates are predominant.
Carbapenem-resistant Klebsiella pneumoniae isolates producing K. pneumoniae carbapenemases (KPC) were first reported in the USA in 2001, and since then, this infection has been reported in Europe, Israel, South America, and China. In Korea, the first KPC-2-producing K. pneumoniae sequence type (ST) 11 strain was detected in 2010. We report the case of a patient with a urinary tract infection caused by KPC-2-producing K. pneumoniae. This is the second report of a KPC-2-producing K. pneumoniae infection in Korea, but the multilocus sequence type was ST258. The KPC-2-producing isolate was resistant to all tested β-lactams (including imipenem and meropenem), amikacin, tobramycin, ciprofloxacin, levofloxacin, and trimethoprim-sulfamethoxazole, but was susceptible to gentamicin, colistin, polymyxin B, and tigecycline. The KPC-2-producing isolate was negative to phenotypic extended-spectrum β-lactamase (ESBL) and AmpC detection tests and positive to modified Hodge test and carbapenemase inhibition test with aminophenylboronic acid.
Background: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated.We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups.Methods: Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction.HBoV-positive patients were categorized into low-and high-viral-load groups using 1.0× 10 6 copies/mL as the threshold value of viral load.Results: Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months.HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age.HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group.Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78× 10 5 copies/ mL vs. 1.94×10 4 copies/mL, P =0.014).Higher pulse rate (P =0.007) and respiratory rate (P =0.021) were observed in patients with a high-viral-load.Conclusions: Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.
Therapy-related ALL (t-ALL) is a rare secondary leukemia that develops after chemotherapy and/or radiotherapy for primary malignancies. Chromosomal 11q23 abnormalities are the most common karyotypic alterations in t-ALL. The t(11;19)(q23;p13) aberration is extremely rare and has not been confirmed at the molecular genetic level. Here, we report a case oft-ALL with t(11;19)(q23;p13.3) and MLL-MLLT1 (alias ENL) gene rearrangement confirmed by cytogenetic analysis, multiplex reverse transcription-PCR (multiplex RT-PCR), and DNA sequencing in a patient who had undergone treatment for breast cancer. A 40-yr-old woman developed acute leukemia 15 months after undergoing 6 cycles of adjuvant chemotherapy (doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2)), radiation therapy (dose, 5,900 cGy), and anticancer endocrine therapy with tamoxifen. The complete blood cell counts and bone marrow examination showed increased blasts and the blasts showed B lineage immunophenotype (positive for CD19, CD34, and cytoplasmic CD79a). Cytogenetic analysis revealed the karyotype 47,XX,+X,t(11;19)(q23;p13.3)[4]/46,XX[16]. FISH analyses, multiplex RT-PCR, and DNA sequencing confirmed the MLL-MLLT1 gene rearrangement. The patient underwent induction chemotherapy with fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (Hyper-CVAD) and achieved complete remission. Subsequently, she underwent consolidation chemotherapy, but died of brain ischemia in the pons and the region of the middle cerebral artery. To our knowledge, this is the first case report of t-ALL with t(11;19)(q23;p13.3) and the MLL-MLLT1 gene rearrangement.
Streptococcus suis infection is an emerging zoonosis in Asia. The most common disease manifestation is meningitis, which is often associated with hearing loss and cochleovestibular signs. S. suis infection in humans mainly occurs among risk groups that have frequent exposure to pigs or raw pork. Here, we report a case of S. suis meningitis in a 67-yr-old pig carcass handler, who presented with dizziness and sensorineural hearing loss followed by headaches. Gram-positive diplococci were isolated from cerebrospinal fluid (CSF) and blood cultures and showed gray-white colonies with α-hemolysis. S. suis was identified from CSF and blood cultures by using a Vitek 2 system (bioMérieux, France), API 20 STREP (bioMérieux), and performing 16S rRNA and tuf gene sequencing. Even after receiving antibiotic treatment, patients with S. suis infection frequently show complications such as hearing impairment and vestibular dysfunction. To the best of our knowledge, this is the first case of S. suis meningitis in Korea. Prevention through public health surveillance is recommended, especially for individuals who have occupational exposures to swine and raw pork.
Background Clostridium difficile infection (CDI) has markedly risen and is associated with hypervirulent ribotype 027 outbreaks in North America and Europe since 2003. The aims of this study were to determine the prevalence of ribotype 027 among C. difficile isolates in Korea, to characterize the ribotype 027 isolates, and to determine the clinical severity of CDI in patients infected with these isolates. Methods A total of 1,251 isolates of C. difficile recovered from stool specimens of suspected CDI patients at two tertiary-care hospitals and one commercial laboratory between 2002 and 2009. Genes for toxin A (tcdA), toxin B (tcdB), and binary toxin (cdtA and cdtB) were detected by PCR. Mutation in the tcdC gene was detected by sequencing after PCR amplification. For molecular genotyping, we performed PCR-ribotyping, pulsed-field gel electrophoresis (PFGE), and multilocus variable-number tandem-repeat analysis (MLVA). Minimum inhibitory concentrations of moxifloxacin were determined using Etest strips (AB bioMérieux, Sweden). Results We identified 7 isolates as ribotype 027. These isolates had the same tcdC mutation as the epidemic strain, and 6 of them were resistant to moxifloxacin. The isolates were categorized into 3 different PFGE types and 7 different MLVA types. All the 7 cases had occurred sporadically. Conclusions C. difficile ribotype 027 is uncommon, but it has emerged in Korea. The spread of this ribotype should be closely monitored in order to avoid an outbreak of CDI in Korea.
BACKGROUND:Myelomatous pleural effusion (MPE) is rare in myeloma patients. We present a consecutive series of patients with MPE in a single institution.METHODS:We retrospectively reviewed the medical records of 19 patients diagnosed with MPE between 1989 and 2008 at the Asan Medical Center. Diagnoses were confirmed by cytologic identification of malignant plasma cells in the pleural fluid.RESULTS:Our patients showed dominance of IgA (36.8%) and IgD (31.6%) subtypes. Of 734 myeloma patients, the incidence of MPE was remarkably high for the IgD myeloma subtype (16.7%), compared to the other subtypes (1.4% for IgG and 4.6% for IgA). At the time of diagnosis of MPE, elevated serum β2-microglobulin, anemia, elevated serum lactate dehydrogenase, and elevated creatinine levels were found in 100%, 89.5%, 83.3%, and 57.9% of the patients, respectively. Approximately one-third (31.3%) of the patients had adenosine deaminase (ADA) activities in their pleural fluid exceeding the upper limit of the reported cutoff values for tuberculous pleural effusion (55.8 U/L). Chromosome 13 abnormality was seen in 77.8% of the tested patients. The median survival period from the development of MPE was 2.8 months.CONCLUSIONS:Patients with MPE have aggressive clinical and laboratory characteristics. The preponderance of IgD myeloma in MPE patients is a noteworthy finding because IgD myeloma is a rare subtype. Elevated ADA activity in the pleural fluid is also noteworthy, and may be helpful for detecting MPE. Physicians treating myeloma patients should monitor the development of MPE and consider the possibility of a worse clinical course.
BACKGROUND:Gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard to identify central precocious puberty (CPP). This test requires multiple blood samples at different time points to measure gonadotropin levels, and is therefore expensive, time-consuming, and uncomfortable for patients. We aimed to simplify the GnRH stimulation test to require fewer blood samples.METHODS:A study of 166 girls with precocious puberty was undertaken. Blood samples were obtained at 0, 15, 30, 45, 60, 90, and 120 min after GnRH administration, and the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured. For each parameter, the sensitivities and specificities were estimated and ROC curves were constructed.RESULTS:One hundred and twenty-eight patients (77.1%) were diagnosed for CPP. Peak LH levels were achieved 30 min after GnRH stimulation in patients with CPP. Further, 98.4% of the 45-min samples were diagnostic for CPP, and the cumulative frequency of LH values of ≥5 IU/L was 100% at 45 min. Using this cut-off value for LH, the ROC curve for LH at 45 min showed the highest sensitivity (98.4%) and specificity (100%) in the diagnosis of CPP.CONCLUSIONS:Values of LH measured from a single blood sample obtained at 45 min in the GnRH stimulation test may be adequate for the diagnosis of CPP. Two samples, taken at 30 and 45 min after stimulation, were able to accurately diagnose CPP in 100% of the patients in this study.
Tuberculosis remains a severe public health problem worldwide. Presently, genotyping is used for conducting epidemiologic and clinical studies on tuberculosis cases. We evaluated the efficacy of the repetitive sequence-based PCR (rep-PCR)-based DiversiLab™ system (bioMérieux, France) over the IS6110-restriction fragment length polymorphism analysis for detecting Mycobacterium tuberculosis. In all, 89 clinical M. tuberculosis isolates collected nationwide from Korea were used. The DiversiLab system allocated the 89 isolates to 8 groups with 1 unique isolate when a similarity level of 95% was applied. Seventy-six isolates of the Beijing family and 13 isolates of non-Beijing family strains were irregularly distributed regardless of rep-PCR groups. The DiversiLab system generated a rapid, sensitive, and standardized result. It can be used to conduct molecular epidemiologic studies to identify clinical M. tuberculosis isolates in Korea.
BACKGROUND:We evaluated the performance of multiplex tandem mass spectrometry (MS/MS) in newborn screening for detection of 6 lysosomal storage disorders (LSDs), namely, Niemann-Pick A/B, Krabbe, Gaucher, Fabry, and Pompe diseases and Hurler syndrome.METHODS:We revised the conditions and procedures of multiplex enzyme assay for the MS/MS analysis and determined the precision of our enzyme assay and the effects of sample amounts and incubation time on the results. We also measured the degree of correlation between the enzyme activities in the dried blood spots (DBSs) and those in the leukocytes. DBSs of 211 normal newborns and 13 newborns with various LSDs were analyzed using our revised methods.RESULTS:The intra- and inter-assay precisions were 2.9-18.7% and 8.1-18.1%, respectively. The amount of product obtained was proportional to the DBS eluate volume, but a slight flattening was observed in the product vs. sample volume curve at higher sample volumes. For each enzyme assay, the amount of product obtained increased linearly with the incubation period (range, 0-24 hr). Passing and Bablok regression analysis revealed that the enzyme activities in the DBSs and those in the leukocytes were favorably correlated. The enzyme activities measured in the DBSs were consistently lower in patients with LSDs than in normal newborns.CONCLUSIONS:The performance of our revised techniques for MS/MS detection and enzyme assays was of the generally acceptable standard. To our knowledge, this is the first report on the use of MS/MS for newborn screening of LSDs in an Asian population.
BACKGROUND:Members of the Acinetobacter calcoaceticus-baumannii (Acb) complex are important opportunistic bacterial pathogens and present significant therapeutic challenges in the treatment of nosocomial infections. In the present study, we investigated the integrons and various genes involved in resistance to carbapenems, aminoglycosides, and fluoroquinolones in 56 imipenem-nonsusceptible Acb complex isolates.METHODS:This study included 44 imipenem-nonsusceptible A. baumannii, 10 Acinetobacter genomic species 3, and 2 Acinetobacter genomic species 13TU strains isolated in Daejeon, Korea. The minimum inhibitory concentrations (MICs) were determined by Etest. PCR and DNA sequencing were used to identify the genes that potentially contribute to each resistance phenotype.RESULTS:All A. baumannii isolates harbored the bla(OXA-51)-like gene, and 21 isolates (47.7%) co-produced OXA-23. However, isolates of Acinetobacter genomic species 3 and 13TU only contained bla(IMP-1) or bla(VIM-2). Most Acb complex isolates (94.6%) harbored class 1 integrons, armA, and/or aminoglycoside-modifying enzymes (AMEs). Of particular note was the fact that armA and aph(3')-Ia were only detected in A. baumannii isolates, which were highly resistant to amikacin (MIC(50)≥256) and gentamicin (MIC(50)≥1,024). In all 44 A. baumannii isolates, resistance to fluoroquinolones was conferred by sense mutations in the gyrA and parC. However, sense mutations in parC were not found in Acinetobacter genomic species 3 or 13TU isolates.CONCLUSIONS:Several differences in carbapenem, aminoglycoside, and fluoroquinolone resistance gene content were detected among Acb complex isolates. However, most Acb complex isolates (87.5%) possessed integrons, carbapenemases, AMEs, and mutations in gyrA. The co-occurrence of several resistance determinants may present a significant threat.
