Results of the HLA Typing Proficiency Survey in Korea, 2000-2002 / 대한진단검사의학회지

BACKGROUND: HLA proficiency survey was started in 1996 in Korea, and the results of the 1996-1998 surveys were reported previously. Here, we report the results of the surveys performed in recent three years (2000-2002). METHODS: Six surveys were carried out with the participation of 52-54 laboratories. For each survey, 3 peripheral blood samples and 2 sera were distributed for 3 HLA class I serology, 3 HLA class I DNA, 3 HLA class II DNA, 6 HLA crossmatch, and 3 PRA tests. RESULTS: Overall consensus of serologic typing was similar to the results of the previous survey: HLA-A 93.5%, HLA-B 88.3%, and HLA-A, B 82.7%. There were an increasing number of the laboratories that were using DNA typing for HLA-DR (51 laboratories, 94%) and HLA-A and B (26 laboratories, 48%). Overall consensus of DNA typing was very high: HLA-A 100%, HLA-B 99.1%, HLAC 97.9%, HLA-DRB1 low/high resolution 99.2/99.0%, HLA-DQB1 low/high resolution 99.3/97.5%. HLA crossmatch (T cells) was reported by 44-49 laboratories, and the use of sensitive methods was increased: AHG 33 laboratories and flow cytometry 7 laboratories. For incompatible (positive) crossmatches, 4.9% (0-14.3%) of cytotoxicity tests and 7.1% (0-16.7%) of flow tests were reported as negative. PRA was reported by 5 laboratories only. CONCLUSIONS: The use of DNA tests for HLA typing and AHG or flow cytometry methods for HLA crossmatch tests has much increased compared to the previous report. A continuous survey program would play an important role in the standardization and maintenance of laboratory proficiency in histocompatibility testing in Korea.

Partial Airway Obstruction with an Armored Tube by Swelling of the Inner Layer / 대한마취과학회지

An Armored tube is known to be the most effective in maintaining of airway patency during anesthesia in any position. Unfortunately, the tube itself may become the cause of airway obstruction. One of the known complications of the armored tube is a separation of the individual latex layers. This can be caused by herniation into the lumen. Diffusion of nitrous oxide into the inner hernia considerably intensifies the obstruction. The bubbles in the tube wall arise during manufacturing as well as during resterilization. A 62-year-old man with herniation of lumbar disc herniation was intubated with a 8.0 mm armored tube for general anesthesia. 30 minutes later, we experienced signs of partial endotracheal tube obstruction including high arterial PCO2 and inspiratory pressure in prone position. Then, tube suction with catheter was done and signs was slightly improved. But, 90 minutes later, passage of suction catheter was impossible. When operation was finished, patient was turned to supine position. We exchanged the tube with another tube and found inner wall herniation into the armored tube lumen caused by layer separation.

Analysis of Ambiguities of HLA-DR Typing using the Dynal RELI(TM) SSO HLA-DRB Kit and Development of an 'Interpretation Program for Koreans' / 대한진단검사의학회지

BACKGROUND: HLA-DR typing kits using reverse-SSO (sequence specific oligonucleotide) method show considerable ambiguities in HLA-DRB1 generic typing. We analyzed the ambiguities of the Dynal RELI(TM) SSO HLA-DRB test (Dynal DRB test) and developed an 'Interpretation Program for Koreans'. METHODS: A total of 3,000 Koreans were typed for HLA-DRB1/B3/B4/B5 using the 36 probe Dynal DRB test and all of the cases showing ambiguities in HLA-DRB1 generic typing were subjected to confirmatory typing using the PCR-single strand conformation polymorphism (SSCP) method. On the basis of these results, an 'Interpretation Program for Koreans'was developed for the 45 probe Dynal DRB test. RESULTS: Among 3,000 Koreans tested by the 36 probe Dynal DRB test, 456 cases (15.2%) showed ambiguities. In 95% of the ambiguity cases (433/456) and 99.2% of the total cases tested (433/3,000), the'most probable type'could be expected from the DRB1 gene frequencies and DRB1-B3/B4/B5 associations in Koreans and these results were in accordance with the confirmatory typing results as well as the results given by the 'Interpretation Program for Koreans'. Similarly, the 'Most Probable'could be assigned by the program in 99.4% (348/350) of the cases tested with the 45 probe Dynal DRB test. CONCLUSIONS: Ambiguity in the Dynal DRB test was observed in >15% of the Korean samples tested. The majority (95%) of the ambiguities could be resolved on the basis of HLA-DRB1 gene frequencies and DRB1-B3/B4/B5 associations in Koreans. Furthermore, using the program developed in this study, the correct assignment of DRB1 generic types was possible without additional typing in the majority (>99%) of the cases tested.

Acute Spontaneous Spinal Epidural Hemorrhage

Spontaneous spinal epidural hemorrhage(SSEH) represent 0.3%~0.9% of spinal epidural-space-occupying lesions. The therapeutic outcome seems to be determined by the accuracy of the diagnosis and by the time interval between the onset of symptom and surgical decompression. Thus, SSEH is a rare spinal emergency and a diagnostic challenge. We experienced two such cases. In one case, the symptoms were confused with those for a ureter stone, aortic aneurysm, spinal cord infarction. That patient completely recovered spontaneously within 2 hours. In the other case, which was initially diagnosed incorrectly as a cerebral infarction, surgical decompression was performed. That patient recovered completely within 1 month.

Positive Rate of HLA Class I Antibodies in Multiparous Korean Women / 대한임상병리학회지

BACKGROUND: Anti-HLA antibodies are most frequently induced by transfusion or pregnancy, and these anibodies can be used as antisera for HLA typing. However these antibodies may elicit adverse reactions such as transfusion reaction or rejection of transplanted organs. In this study, frequency and specificities of antibodies against HLA class I antigens were determined in multiparous Korean women. METHODS: Sera from 671 multiparous women were tested for anti-HLA antibody screening by standard microlymphocytotoxicity test using 49~50 lymphocyte panels. PRA(panel reactive antibody) values were calculated as percentage of postive panels among total lymphocyte panels tested. HLA antibody specificities and reaction strengths were determined by analysis of serologic reaction patterns. RESULTS: A total of 671 sera were tested and 124 sera(18.5%) were positive for HLA antibodies. Among HLA antibody-positive sera(n=124), 117(94.4%) showed PRA values of 50%. Specificities of HLA antibodies were identified in 51 sera(41.1%) and 18 sera(14.5%) contained reagent quality antibodies(r> or =0.8, SI> or =70%), corresponding to 2.7% of total multiparous women. Among these, 4 sera had monospecific HLA antibodies and 14 sera had HLA antibodies against two or more antigens: 4 sera containing HLA antibodies against 7 CREG(cross reactive group), 5 sera containing antibodies against 5 CREG. CONCLUSION: Through the analysis of frequency and specificity of HLA antibodies in 671 multiparous women, it is concluded that HLA antisera can be obtained from multiparous women as effectively as from pregnant women. The frequency of high level of sensitization(PRA>50%), which can elicit problems in relation to transfusion or organ transplantation, is very low(1.0%).

Two-Year Study on the HLA Typing Proficiency Survey in Korea, 1996-1998 / 대한임상병리학회지

BACKGROUND: To standardize the histocompatibility testing among different laboratories, we have developed and performed a proficiency survey (external quality control) program in HLA typing with participation of nationwide HLA laboratories in Korea. METHODS: During a two-year period, four trials of proficiency survey were performed with 35-39 participating laboratories. Test number and items included in each survey were 3 HLA class Iantigen typings, 2 class II DNA typings, and 6 HLA crossmatch tests (3 cells x 2 sera). RESULTS: HLA class I serological typing was performed on a total of 12 whole blood specimens representing 7 HLA-A and 17 HLA-B antigens. More than 90% of the laboratories correctly identified 7 HLA-A (A2, A3, A11, A24, A26, A30, A33) and 13 HLA-B antigens (B7, B8, B13, B14, B27, B35, B48, B51, B52, B54, B58, B60, B61). Lower consensus (<90%) was obtained for B62, B67, B75, and B15 (B*1511). Considerable difference in antigen detection rate was observed between different commercial trays used. HLA class II DNA typing was performed on a total of 8 DNA specimens representing 13 HLA-DRB1 and 11 DQB1 alleles. For HLA-DRB1 typing (16-26 laboratories), correct assignment rate was very high (98%) for generic level, but lower (80%) for allele level. For DQB1 typing (5-8 laboratories), 100% consensus was obtained for allelic level. With respect to HLA crossmatching, detection rate of incompatibility was very low in the 1st trial. HLA crossmatch workshop on the standardization of typing methods was performed after the 1st trial, and thereafter the number of laboratories using sensitive methods were increased and the detection rate of incompatible crossmatch was much improved (1st 29-46%, 2nd 78-97%). CONCLUSIONS: Through these HLA typing proficiency surveys, standardization of test methods and improvement of typing results were obtained. A continuous survey program would play an important role for improving success rate of organ transplantations in Korea.