The Experience of RHD Genotyping in D-negative Blood Donors / 대한수혈학회지

Background@#There have been some domestic and overseas cases of anti-D alloimmunization caused by the transfusion of serologically D-negative blood. However, it is difficult to distinguish between true D-negative and DEL variants using conventional serologic typing. Therefore, we established the RHD genotyping algorithm for the detection of DEL variants and applied this algorithm to serologic D negative donors who voluntarily consented to testing. @*Methods@#From September 2016 to December 2020, 216 RHD negative donors who were C＋ and/or E+ in previous serologic typing were recruited. The screening test was PCR amplification of the RHD exons 4, 7, 10, and a promotor. Based on the results of PCR screening, true D-negative samples and RHD variants (including DEL) were discriminated. When the result was a RHD variant, exon 9 was sequenced to identify the nucleotide changes. Full sequencing was performed if no mutations were detected at exon 9. @*Results@#Among the 216 participants, 39 cases with the C−E−c＋e＋ phenotypes that did not meet the recruitment criteria were excluded from data analysis. Among the remaining 177 samples, 68 cases (38.4%) were RHD total deletions, 35 cases (19.8%) were RHD-CE-D hybrids, and 74 cases (41.8%) were RHD variants. Among the cases of RHD variants, 73 cases (98.6%) had c.1227G＞A substitutions and were confirmed as Asian-type DEL. @*Conclusion@#Seventy-four cases of serologic D negative donors were reclassified as RHD variants by RHD genotyping. This is believed to have contributed to the improvement of transfusion safety by lowering the risk of anti-D alloimmunization in D-negative patients.

Analysis of Malaria Nucleic Acid Amplification Test Under the Temporary Permission in Malaria Blood Donation Restricted Area / 대한수혈학회지

There were 10 cases of transfusion-transmitted P. vivax malaria from 1990 to 2021. The Korean Centers for Disease Control and Prevention (KCDC) designated the areas showing a high frequency of malaria as a malaria-endemic area and has restricted whole blood donation from these areas. While the number of malaria infections has declined in recent years, the blood inventory has declined sharply due to the COVID-19 pandemic. Accordingly, the Ministry of Health and Welfare temporarily approved the donation of whole blood from malaria-endemic areas to secure the supply of blood products. In the present study, an anti-malaria screening and nucleic acid amplification test (NAT) was performed on samples collected from the malaria-endemic areas from May 20 to June 30, 2020. A total of 14,741 samples were collected and tested. NAT was performed for 1096 runs to test all the collected samples. The 117 (0.79%) samples showed initial reactive results due to the contamination of abnormal PCR results. Negative results were obtained for the samples showing initial reactive results using a duplicated re-test. From the NAT tests, no sample showed a true positive result. The results of the malaria antibody screening test were reactive in 10 out of the 14,741 samples. The malaria antibody screening needs to be reviewed through further study because of its insufficient sensitivity and specificity. According to this study, excluding the 10 reactive malaria antibodies, additional blood components could be secured from 14,731 blood donors for a stable blood supply.

The Experience of RHD Genotyping in D-negative Blood Donors / 대한수혈학회지

Background@#There have been some domestic and overseas cases of anti-D alloimmunization caused by the transfusion of serologically D-negative blood. However, it is difficult to distinguish between true D-negative and DEL variants using conventional serologic typing. Therefore, we established the RHD genotyping algorithm for the detection of DEL variants and applied this algorithm to serologic D negative donors who voluntarily consented to testing. @*Methods@#From September 2016 to December 2020, 216 RHD negative donors who were C＋ and/or E+ in previous serologic typing were recruited. The screening test was PCR amplification of the RHD exons 4, 7, 10, and a promotor. Based on the results of PCR screening, true D-negative samples and RHD variants (including DEL) were discriminated. When the result was a RHD variant, exon 9 was sequenced to identify the nucleotide changes. Full sequencing was performed if no mutations were detected at exon 9. @*Results@#Among the 216 participants, 39 cases with the C−E−c＋e＋ phenotypes that did not meet the recruitment criteria were excluded from data analysis. Among the remaining 177 samples, 68 cases (38.4%) were RHD total deletions, 35 cases (19.8%) were RHD-CE-D hybrids, and 74 cases (41.8%) were RHD variants. Among the cases of RHD variants, 73 cases (98.6%) had c.1227G＞A substitutions and were confirmed as Asian-type DEL. @*Conclusion@#Seventy-four cases of serologic D negative donors were reclassified as RHD variants by RHD genotyping. This is believed to have contributed to the improvement of transfusion safety by lowering the risk of anti-D alloimmunization in D-negative patients.

Analysis of Malaria Nucleic Acid Amplification Test Under the Temporary Permission in Malaria Blood Donation Restricted Area / 대한수혈학회지

There were 10 cases of transfusion-transmitted P. vivax malaria from 1990 to 2021. The Korean Centers for Disease Control and Prevention (KCDC) designated the areas showing a high frequency of malaria as a malaria-endemic area and has restricted whole blood donation from these areas. While the number of malaria infections has declined in recent years, the blood inventory has declined sharply due to the COVID-19 pandemic. Accordingly, the Ministry of Health and Welfare temporarily approved the donation of whole blood from malaria-endemic areas to secure the supply of blood products. In the present study, an anti-malaria screening and nucleic acid amplification test (NAT) was performed on samples collected from the malaria-endemic areas from May 20 to June 30, 2020. A total of 14,741 samples were collected and tested. NAT was performed for 1096 runs to test all the collected samples. The 117 (0.79%) samples showed initial reactive results due to the contamination of abnormal PCR results. Negative results were obtained for the samples showing initial reactive results using a duplicated re-test. From the NAT tests, no sample showed a true positive result. The results of the malaria antibody screening test were reactive in 10 out of the 14,741 samples. The malaria antibody screening needs to be reviewed through further study because of its insufficient sensitivity and specificity. According to this study, excluding the 10 reactive malaria antibodies, additional blood components could be secured from 14,731 blood donors for a stable blood supply.

A Case of the False-negative D Phenotype in a Neonate with a Strongly Positive Direct Antiglobin Test Rest

Accurate D antigen blood typing is needed owing to the clinical importance of the Rh blood group. We describe a female infant who was suspected to suffer from Rh incompatible hemolytic disease of the newborn, and who showed a strong positive direct antiglobin test (DAT) result and false red blood cell (RBC) agglutination in D typing. Using chloroquine dissociation of IgG, we confirmed that the antibodies coating her RBCs were of anti-D type. D typing with 0.8% RBC suspensions in saline using saline gel cards showed 2+ RBC agglutinations. After increasing the incubation time of dissociation by chloroquine for up to 4 hr, the dissociated RBCs began to show agglutination in both the tube technique (2+) and the gel card technique (4+) for D typing, although the DAT rest was still positive. Therefore, in order to prevent mistyping as a false-negative D blood group, whenever the D blood typing of a patient with a strong positive DAT rest does not show RBC agglutination, retesting of the D blood typing is recommended by using saline-suspended RBCs or dissociated RBCs.

Three Cases of Secondary Hemophagocytic Lymphohistiocytosis Associated with Systemic Erythematosus Lupus

Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder characterized by fever, pancytopenia, hyperferritinemia, and phagocytosis of hematopoietic cells in bone marrow, liver, or lymph nodes. HLH can occur during the course of systemic lupus erythematosus (SLE), but can also be a presenting manifestation. Because development of pancytopenia occurs in less than 10 percent of SLE cases, investigation for HLH is necessary when otherwise unexplained pancytopenia persists despite adequate treatment. We experienced three cases of secondary HLH associated with SLE. Among the three patients, two patients developed HLH during the clinical course of SLE. The other patient who presented with pancytopenia was first diagnosed with HLH, and later with SLE. In her case, HLH turned out to be a presenting manifestation of SLE. We report on three successfully treated cases, and discuss the prevalence, characteristics, treatments, and prognosis of secondary HLH associated with SLE.

Evaluation of the VITROS 3600 Analyzer for HBsAg / 대한수혈학회지

BACKGROUND: The VITROS 3600 (Ortho Clinical Diagnostics, Johnson & Johnson, Buckinghamshire, UK), which uses the enhanced chemiluminescence immunoassay, has recently been introduced; however, it has not been evaluated for detection of HBsAg in Korea. We evaluated the ability of the VITROS 3600 for detection of HBsAg, compared with the ARCHITECT i2000 (Abbott Laboratories, Abbott Park, IL, USA), which is used widely in Korea to help in selection of an analyzer for detection of HBsAg. METHODS: A total of 800 samples were tested randomly for HBsAg and 150 samples with positive HBV DNA detected by real-time PCR were used in this study. Precision, agreement, and Pearson correlations between two analyzers were evaluated. RESULTS: The total standard deviations (SD) were 0.016 and 0.183 for the negative and positive HBsAg controls, respectively; the precision met the criteria suggested by the manufacturer. There were 100% agreements for the 800 random samples (positive 33, negative 767) and 150 samples with HBV DNA (positive 148, negative 2) between two analyzers. In addition, good correlation was observed between two analyzers for the 767 HBsAg negative samples (r=0.691, P=0.004), and 148 HBV DNA positive samples (r=0.763, P<0.001). CONCLUSION: The VITROS 3600 showed good precision and agreement. And, correlation between the VITROS 3600 and the ARCHITECT i2000 was excellent. Therefore, this result will be helpful in selection of an analyzer for detection of HBsAg.

A Case of Epstein-Barr Virus Infection with Gall Bladder and Common Bile Duct Stones in an Otherwise Healthy Child / 대한소아소화기영양학회지

Cholelithiasis and choledocholithiasis are uncommon pediatric diseases, although clinicians have seen them with increasing frequency in children in recent years. Moreover, no case of Epstein-Barr virus (EBV) infection with cholelithiasis and choledocholithiasis has been previously reported in the English literature. We report a pediatric patient with EBV infection, a gall bladder stone, and a common bile duct stone, may have had GB and CBD stones prior to her EBV infection, whom we successfully treated with antibiotics and laparoscopic cholecystectomy for cholecystitis.