Analysis of Unexpected Antibodies Detected in Children: A Single Center Study for 7 Years / 대한수혈학회지

BACKGROUND: Frequency and distribution of unexpected red cell antibodies vary according to study population and method of antibody detection. The frequency and specificities of unexpected red cell antibodies were analyzed and compared in adults and children. METHODS: We analyzed the results of antibody screening and identification tests performed from November of 2008 to June of 2015 at Pusan National University Yangsan Hospital. A commercially available three-cell antigen panel, DiaCell I, II and Dia (DiaMed, Murten, Switzerland) for antibody screening, LISS/Coombs and NaCl/Enzyme card and the ID-Dia Panel (DiaMed, Murten, Switzerland) for antibody identification were used. RESULTS: Among the 91,145 adults, 1,804 (1.97%) had positive results for antibody screening test and 11,457 children, 447 (3.90%) had positive results. In adults, the most frequently detected unexpected antibody was anti-E (103 samples), followed by by anti-E&c (51 samples), anti-Lea (27 samples), and anti-Dia (27 samples). In children, anti-M (7 samples), anti-E&c (5 samples), anti-E (4 samples), and anti-D (4 samples) were most frequently detected. Among 9 pediatric patients with anti-E or anti-E&c, 5 patients were proven as hemolytic disease of the fetus and newborn. CONCLUSION: In this study, the positive rate of unexpected antibody screening in children was higher than in adults. Distribution of unexpected antibody differed between children and adults. It may be related to the frequent cardiac surgery performed in children at our hospital. No studies have been conducted in children. Our research may provide data for the frequency and characteristics of red cell antibodies in children.

Cutoff Value of PB CD34+ Cells for Optimization of PBSC Collection / 대한수혈학회지

BACKGROUND: Peripheral hematopoietic stem cell mobilization is increasing due to its advantages. For successful engraftment, obtaining sufficient stem cells is prerequisite. The number of CD34+ cells of collected blood are widely used to predict the engraftment potential. To determine the optimal point for collection of peripheral blood stem cell (PBSC), enumeration of the number of CD34+ cells in peripheral blood (PB) is known to be helpful. The purpose of this study is to analyze cutoff value of CD34+ cells in PB. METHODS: We analyzed 407 cases of autologous PBSC collection and 107 cases of allogenic PBSC collection during 2004~2009 in Pusan National University Hospital. Complete blood count, HPC fraction and number, CD34+ cells in PB and product of PBSC collection were analyzed. RESULTS: The each number of mononuclear cells and HPC in PB showed a strong correlation with CD34+ cells in PB. A strong correlation between the number of circulation CD34+ cells in PB on the day of collection and the number of collected CD34+ cells was found. The ROC curve revealed that the cutoff point having the optimal sensitivity and specificity at 8.5/uL for target CD34+ cells > or =1.0x10(6)/kg, 10.5/uL for target CD34+ cells > or =1.5x10(6)/kg and 13.5/uL for target CD34+ cells > or =2.0x10(6)/kg in this study. CONCLUSION: To obtain a sufficient yield of CD34+ cells during PBSC collection, determination of cut off point for each target CD34+ cells//kg is helpful to decide the collection.

Performance Evaluation of Real-Q Enterovirus Quantification Kit for Enterovirus by Real-time PCR / 대한진단검사의학회지

BACKGROUND: Molecular methods have enabled rapid diagnosis of aseptic meningitis and have reduced both unnecessary therapeutic interventions and medical costs. In this study, we evaluated the analytical performance of the recently developed Real-Q Enterovirus Quantification kit (BioSewoom Inc., Korea). METHODS: We evaluated the detection limit, precision, linearity, and cross-reactivity of the Real-Q Enterovirus Quantification kit and compared it with the conventional PCR method. From March to September 2009, we tested 91 CSF specimens from patients who visited the pediatrics department of the university hospital with symptoms of aseptic meningitis or infantile sepsis, and we also tested 48 CSF specimens from patients with febrile convulsion for differential diagnosis. RESULTS: The Real-Q Enterovirus Quantification kit showed good linearity (r=0.997) within a range from 3x10(2) to 3x10(10) copies/mL, and the detection limit of the kit was 83 copies/mL. The within-run, between-run, and between-day CVs were 5.3-7.6%, 9.5-12.3%, and 11.4-13.4%, respectively. There was no cross reactivity between enteroviruses and various microorganisms. Positive results were obtained for 39.1% (25/64) of the patients suspected of aseptic meningitis and 44.4% (12/27) of the patients suspected of infantile sepsis. However, among the 48 children with febrile conversion, only 4 were positive for enterovirus. Further, the concordance with conventional PCR was high (73/74). CONCLUSIONS: The Real-Q Enterovirus Quantification kit showed excellent linearity and high reliability with a broad reportable range. It showed good detection rate when used with clinical specimens and also showed a high concordance with the conventional method. Therefore, this assay would be clinically useful not only in diagnosis of aseptic meningitis but also in differential diagnosis of infantile sepsis.

Evaluation of ARCHITECT HCV Core Antigen Assay / 대한진단검사의학회지

BACKGROUND: Hepatitis C virus (HCV) core antigen (Ag) levels are known to be well correlating with HCV RNA levels, and may be used as an alternative marker of HCV replication for monitoring the response to HCV treatment. However, the low sensitivity of HCV core Ag assay has been an obstacle for clinical use. In this study, recently developed ARCHITECT HCV Ag assay (Abbott Laboratories, USA) was evaluated for analytical performance and clinical usefulness. METHODS: A total of 109 sera from HCV infected patients including various genotypes of HCV (1b, 2, 2a/2c, 2b, and 3a) and 20 sera from healthy donors were used for evaluating the sensitivity, precision, and linearity of the HCV core Ag assay. The cross reactivity with HIV, hepatitis B virus and myeloma proteins (N=5, each) and correlation with HCV RNA PCR assay were also evaluated. RESULTS: The sensitivity of the HCV core Ag assay was 97.2% (106/109) and there were no false positive results and cross reactivity. The within-run, between-run and between-day CVs were 3.0%, 2.5% and 3.0%, respectively. The levels of HCV core antigen showed a good correlation with those of HCV RNA quantification (r=0.940). The HCV Ag assay showed an excellent linearity in the range from 0.63 to 17,114 fmol/L (r=0.999). CONCLUSIONS: The ARCHITECT HCV Ag assay was good in sensitivity, precision, and linearity and its results well correlated with HCV RNA levels. This assay could be used as a good marker of viral replication for monitoring the therapy response in chronically HCV infected patients.