Development and Application of a Cell-Based Assay for LRP4 Antibody Associated With Myasthenia Gravis

Background@#and Purpose Among patients with double-seronegative myasthenia gravis (dSN-MG) who do not have detectable antibodies against acetylcholine receptor or musclespecific tyrosine kinase, autoantibodies against low-density lipoprotein receptor-related protein 4 (LRP4-Ab) have been detected recently. The purpose of this study was to develop an in-house cell-based assay (CBA) to detect LRP4-Ab and to apply it to samples from patients with MG. @*Methods@#The complementary DNA of LRP4 fused into a vector plasmid containing GFP was transfected into human embryonic kidney 293 (HEK293) cells. LRP4 expression in the transfected HEK293 cells was assessed using the reverse-transcription polymerase chain reaction (RT-PCR), Western blotting, and immunocytochemistry. The CBA included 252 sera collected from 202 patients with MG and 38 with other neuromuscular diseases, and 12 healthy controls. The transfected HEK293 cells were incubated using sera and antihuman immunoglobulin G antibodies conjugated with Alexa Fluor 594. The presence of LRP4-Ab was determined based on the fluorescence intensity and the localization in fluorescence microscopy. @*Results@#The expressions of the mRNA and protein of LRP4 in the transfected HEK293 cells were confirmed using RT-PCR and Western blotting, respectively. Immunocytochemistry indicated LPR4 expression on the cell membrane. Among 202 patients with MG including 53 with dSN-MG, LRP4-Ab were positive in 3 patients who were all double seronegative. LRP4-Ab were not detected in the patients with other neuromuscular diseases or the healthy controls. @*Conclusions@#A CBA for detecting LRP4-Ab associated with MG has been developed, and was used to find LRP4-Ab in the sera of patients with MG.

Multiple Embolic Infarcts Caused by Infective Endocarditis Associated with Atrioesophageal Fistula after Percutaneous Radiofrequency Catheter Ablation for Atrial Fibrillation

Infective endocarditis (IE) is not a common cause of stroke. Considering the high mortality rates, however, IE should always be considered as a possible cause of stroke even when the chances are low. Atrioesophageal fistula is a life-threatening condition that can cause IE and subsequent stroke, but the diagnosis is often delayed due to its rarity. We report a case of multiple embolic infarcts caused by infective endocarditis associated with atrioesophageal fistula after radiofrequency catheter ablation for atrial fibrillation.

Discrepancies between Human Leukocyte Antigen Registry Typing and Confirmatory Typing Results of Unrelated Hematopoietic Stem Cell Donors / 대한진단검사의학회지

BACKGROUND: In unrelated hematopoietic stem cell transplantation, the accuracy of HLA registry typing (RT) of donors is important for timely search and coordination of HLA-matched donors. We analyzed discrepancies between HLA RT and confirmatory typing (CT) results of stem cell donors in Korean and foreign registries. METHODS: We analyzed the HLA typing results of 834 donors for whom CT was performed at Seoul National University Hospital between April 1997 and March 2010. For CT, DNA typing was used in majority of the cases and HLA-A and HLA-B serological typing was used in some early cases. The discrepancies between the typing results were analyzed at the serological/generic level. RESULTS: The overall discrepancy rate (RT error rate) was 3.2%, and the rate was similar in the Korean and foreign registries. The discrepancy rates in the Korean and foreign registries were more than 10% in the 1997-2001 searches, but decreased to less than 3% in the 2002-2010 searches. Analysis of 19 cases of RT errors in the Korean registry revealed 3 cases of sample switchover errors and 16 cases of typing errors in one of the HLA-A, HLA-B, or HLA-DR loci. The RT error rate in Japan Marrow Donor Program was lower than those in other foreign registries. CONCLUSIONS: The error rate of HLA RT results of unrelated stem cell donors in the Korean registry was similar to those in the foreign registries, and has decreased in the recent searches following the change in the typing method from serological to DNA typing.

Allelic and Haplotypic Diversity of HLA-A, -B, -C, and -DRB1 Genes in Koreans Defined by High-resolution DNA Typing / 대한진단검사의학회지

BACKGROUND: In this study, we used high-resolution DNA typing to investigate the distribution of HLA alleles and haplotypes in Koreans. METHODS: HLA-A, -B, -C, and -DRB1 alleles were genotyped at the allelic (4-digit) level in 474 healthy Koreans. HLA genotyping was performed in two steps. Initially, serologic typing or generic-level DNA typing was performed using the PCR-sequence-specific oligonucleotide method, and then allelic DNA typing (exons 2 and 3 for class I, and exon 2 for DRB1) was carried out using the PCR-single-strand conformation polymorphism method or sequence-based typing. HLA allele and haplotype frequencies and linkage disequilibrium values were calculated by the maximum likelihood method using a computer program developed for the 11th International Histocompatibility Workshop. RESULTS: A total of 21 HLA-A, 40 HLA-B, 22 HLA-C, and 29 HLA-DRB1 alleles were found in Koreans. The most frequent alleles in each locus with frequencies of > or =10% were, in decreasing order of frequency, as follows: A*24:02, A*02:01, A*33:03; B*51:01; C*01:02, C*03:03; and DRB1*09:01. The numbers of two- and three-locus haplotypes with frequencies of >0.5% were as follows: 44 A-C, 42 B-C, 51 A-B, 52 B-DRB1, 42 A-C-B, and 34 A-B-DRB1. Thirteen A-B-DRB1 haplotypes with frequencies of > or =1.0% comprised 26.0% of the total haplotypes. The six most common haplotypes were as follows: A*33:03-B*44:03-DRB1*13:02 (3.7%), A*33:03-B*44:03-DRB1*07:01 (3.0%), A*33:03-B*58:01-DRB1*13:02 (3.0%), A*24:02-B*07:02-DRB1*01:01 (2.8%), A*30:01-B*13:02-DRB1*07:01 (2.3%), and A*11:01-B*15:01-DRB1*04:06 (2.2%). CONCLUSIONS: The information obtained in this study can be used as basic data for Koreans in the fields of organ transplantation, disease association, and anthropologic studies.

Neuropsychological Characteristics of Schizophrenic Patients who Committed Homicide / 신경정신의학

OBJECTIVES: There is a moderate but significant association between schizophrenia and violence. The purpose of this study is to investigate the relationship between violence and brain cognitive functions in schizophrenic patients who have committed homicide using neuropsychological tests. METHODS: The study involved three group of subjects: schizophrenics who have committed homicide (n=51), schizophrenics who have not committed homicide (n=50) and normal control (n=50). Intelligence test (K-WAIS), memory test (Rey-Kim Memory Test) and executive function test (Stroop test, WCST) as well as Positive and Negative Syndrome Scale (PANSS) and Structured Interview for DSM-IV Personality (SIDP) were administered by trained researchers. RESULTS: There were no significant differences in demographic variables among groups. Schizophrenic patients showed overall cognitive deficit in intelligence, memory and executive functions, regardless of homicide behavior. Homicidal schizophrenic group was not significantly different from non-homicidal schizophrenic group in every cognitive domain. There was no significant correlation between index scores of cognitive functions and Life History of Aggression assessment (LHA). However, index scores of cognitive functions were negatively correlated with the PANSS and schizotypal trait scores. CONCLUSION: Cognitive dysfunction is common across both schizophrenic groups. It doesn't significantly correlate with homicidal experience, but it correlates with the schizophrenic symptom domains.

Comparison of the Rate of Detection of Immunoglobulin Heavy Chain Gene Rearrangement by Fluoresecence In Situ Hybridization Probes in Multiple Myeloma / 대한진단검사의학회지

BACKGROUND: Immunoglobulin heavy chain (IgH) gene rearrangement, which is frequently observed in multiple myeloma, can now be detected easily by using a fluorescence in situ hybridization (FISH) method. The aim of this study was to determine the detection rate and compare the utility of the three most commonly used probes: IGH/CCND1 dual color, dual fusion probe; IGH/BCL2 dual color, dual fusion probe; and IGH dual color break apart rearrangement probe; all from Vysis Products (Downers Grove, IL, USA). METHODS: From October 1994 to July 2003, 99 patients were diagnosed as multiple myeloma at Seoul National University Hospital, Asan Medical Center and Gachon University Gil hospital. We applied the three different probes of IgH FISH on bone marrow specimens from the 99 Korean patients with multiple myeloma to detect IgH gene rearrangement. RESULTS: Forty-one (41.4%) of the 99 patients had IgH gene rearrangement. Of those 41 patients, 23 (56.1%) showed positive to all three probes, but the remaining 18 (43.9%) showed a discrepancy between the three probes: 13 (72.2%) of the 18 patients were only positive to the IGH dual color break apart rearrangement probe and the detection rate was 39.6% on the average. CONCLUSIONS: These results demonstrate that IGH dual color break apart rearrangement probe is superior to the other two probes in qualitative and quantitative ways. Thus, we recommend IGH dual color break apart rearrangement probe for the diagnosis and monitoring of multiple myeloma.

Clinical Characteristics of Schizophrenic Patients who Committed Homicide / 신경정신의학

OBJECTIVES: Recent studies have shown that schizophrenic patients are at increased risk to commit acts of aggression, and aggressive behaviors have severe critical results for the patients and victims. The purpose of the present study is to assess the homicidal behaviors of schizophrenic patients as a extreme case of aggressiveness. METHODS: 93 homicidal schizophrenic patients and 93 non-homicidal schizophrenic patients participated in this study. Diagnostic evaluation was made with SCID (Structured Clinical Interview for DSM-IV), and personality trait was evaluated with SIDP (Structured Interview for DSM-IV Personality Disorders). Symptom evaluation was done with PANSS (Positive And Negative Syndrome Scale), and violent behaviors were assessed with LHA (Life History of Aggression) and OAS (Overt Aggression Scale). RESULTS: There were no significant differences in demographic variables, schizotypal personality trait and antisocial personality trait between two groups. Mean age at homicidal commitment was 34+/-8.9 years and 9.8+/-7.5 years after the onset of illness. The major criminal victims were the parents of the patients(N=49, 53.7%). The aggressiveness was higher in homicidal schizophrenic patients in LHA and OAS scales. There were statistical significances in separate items of the PANSS scale such as excitement (P4), poor rapport (N3), lack of judgement and insight (G12), disturbance of volition (G13), poor impulse control (G14) and active social avoidnance (G16), but not in the positive, negative, general subscales and the total scores of the PANSS scale. CONCLUSION: Excitement and poor impulse control persisted in homicidal schizophrenics, although overt psychotic symptoms decline after proper treatment. Homicidal behavior can be preventive if proper treatment for excitement and poor impulse control are given.

Detection of an AB(weak) Blood Group by Genotyping / 대한수혈학회지

Since precise ABO blood group typing is the most important part of a safe blood transfusion, the cause of an ABO discrepancy should be determined before issuing blood. The authors confirmed the ABO blood group of a 25-year-healthy male using genotyping method in those who showed an ABO blood group discrepancy between the cell and serum types. ABO typing, saliva test, adsorption elution test and serum transferase assay were performed and the presence of a weak B substance and B transferase was suspected without any evidence of the B antigen on red blood cells. Polymerase-chain-reaction restriction-fragment-length-polymorphism (PCR-RFLP) analysis was performed using the restriction enzymes including BstE II, Pvu II, BssH II, Alu I, and Mva I. The genotyping result showed a normal A allele and B allele. DNA analysis of exons 6 and 7 revealed normal A and B sequences. Therefore, we confirmed A(1)B(weak) blood type.