Factors Predicting Peripheral Blood Stem Cell Collection: Analysis of Korean Patients at a Single Center / 대한수혈학회지

BACKGROUND: Peripheral blood stem cell (PBSC) transplantation is a curative treatment in various hematologic malignancies and some solid cancers. Effective mobilization and collection of PBSC is essential for successful PBSC transplantation. The aim of this study was to investigate the useful factors for predicting PBSC collection using multivariate analysis. METHODS: We retrospectively reviewed the medical records of 170 allogeneic and 389 autologous donors at Chonnam National University Hwasun Hospital between 2005 and 2012. Donor groups were divided into three groups (failure group, suboptimal group, and optimal group) according to the total CD34+ yield. Donors were compared regarding age, sex, body weight, disease, complete blood count, hematopoietic progenitor cell (HPC) parameter of automated cell counter, process volume, number of leukapheresis procedures, prior mobilization history, type of vascular access and instrument. RESULTS: In allogeneic PBSC collections (n=170), the collection failure group showed lower baseline (premobilization) white blood cell (WBC) (P=0.004) and HPC (P<0.001) than the optimal group. In autologous PBSC collections (n=389), the collection failure group showed lower baseline HPC and more frequent prior mobilization history (P<0.001) than the suboptimal and optimal group. In multivariate analysis, older age, lower number of leukapheresis procedures, and prior mobilization history were risk factors associated with mobilization failure. CONCLUSION: Our data suggest that baseline WBC and HPC would be useful for predicting poor mobilizer in allogeneic PBSC collection, whereas baseline HPC would be useful in autologous PBSC collection. Conventional chemotherapy and G-CSF based remobilization would not be helpful to proven poor mobilizer in previous mobilization.

Direct Measurement of Serum Immunoglobulin Heavy and Light Chain Pairs for Identification of Monoclonal Gammopathy and a Performance Comparison with Capillary Electrophoresis

BACKGROUND: Determination of monoclonal gammopathy through conventional protein electrophoresis is sometimes difficult because of the presence of large proteins such as haptoglobin and transferrin, which may obscure the results. Ambiguity in an electrophoresis band can give rise to confusion or difficulty in interpretation. The heavy chain/light chain assay (HLC assay) using Hevylite antibody (The Binding Site, UK) has recently been developed for the accurate measurement of monoclonal proteins. We compared the immunotyping (IT) profiles to the immunoglobulin (Ig) heavy/light chain measurements obtained using the HLC assay and observed the ratios between intact Ig kappa and lambda. METHODS: We collected 35 and 28 sera from patients with suspicious and definitive monoclonal protein, respectively. Then we performed serum protein electrophoresis (SPEP) and IT by Capillarys2 (Sebia, USA). Monoclonal protein production was investigated using Freelite antibody (The Binding Site) and specific Ig(G, A)kappa and Ig(G, A)lambda Hevylite antibodies. The results were analyzed using PASW 18.0 for Windows (IBM, USA). RESULTS: Direct measurement of Ig heavy/light chains showed discordant IT results for 12 (34.2%) of 35 patients' sera with suspicious SPEP pattern and identical IT results for 28 patients' sera with definitive monoclonal peak in the SPEP results. Overall, the results of the HLC assay and IT showed good agreement (kappa=0.718, P=0.000 by cross-tabulation Gamma, Kappa analysis). CONCLUSIONS: The results of direct measurement of serum Ig heavy chain/light chain pairs were comparable to those of IT and were helpful for determination of monoclonality in the case of ambiguous electrophoresis results. Measurement of the heavy chain/light chain pair ratio also allowed precise quantification of the monoclonal Igs with ambiguous electrophoresis patterns and identification or discrimination of clonality.

In Vitro Fluconazole and Voriconazole Susceptibilities of Candida Bloodstream Isolates in Korea: Use of the CLSI and EUCAST Epidemiological Cutoff Values

BACKGROUND: At present, the clinical breakpoints (CBPs) of both fluconazole and voriconazole are available only for 3 common Candida species in the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methods. Epidemiological cutoff values (ECVs) were recently applied to both methods to detect the emergence of acquired resistance (i.e., non-wild-type isolates) among 5 common Candida species. METHODS: We performed a nationwide study to determine the fluconazole and voriconazole susceptibility of Candida bloodstream isolates (BSIs) using both the CLSI and EUCAST methods. A total of 423 BSIs of 5 Candida species were collected from 8 hospitals. The azole susceptibilities were assessed on the basis of the species-specific CBPs and ECVs. RESULTS: Of the 341 BSIs of 3 common Candida species (i.e., C. albicans, C. tropicalis, and C. parapsilosis), 0.3% and 0.9%, 0.0% and 1.5% of isolates were categorized as fluconazole and voriconazole resistant according to the CLSI and EUCAST CBPs, respectively. Of 423 total BSIs, 1.4% and 2.6% had fluconazole minimum inhibitory concentrations (MICs) exceeding the ECVs according to the CLSI and EUCAST, respectively; 1.0% and 2.1% had voriconazole MICs exceeding the ECVs according to the CLSI and EUCAST, respectively. Categorical agreement between the methods using ECVs was 98.3% for fluconazole and 98.3% for voriconazole. CONCLUSIONS: The EUCAST and CLSI methods using ECVs provide highly concordant results. Moreover, non-wild-type isolates with possibly acquired azole resistance were rare among the BSIs of 5 common Candida species in Korea.

In Vitro Fluconazole and Voriconazole Susceptibilities of Candida Bloodstream Isolates in Korea: Use of the CLSI and EUCAST Epidemiological Cutoff Values

BACKGROUND: At present, the clinical breakpoints (CBPs) of both fluconazole and voriconazole are available only for 3 common Candida species in the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methods. Epidemiological cutoff values (ECVs) were recently applied to both methods to detect the emergence of acquired resistance (i.e., non-wild-type isolates) among 5 common Candida species. METHODS: We performed a nationwide study to determine the fluconazole and voriconazole susceptibility of Candida bloodstream isolates (BSIs) using both the CLSI and EUCAST methods. A total of 423 BSIs of 5 Candida species were collected from 8 hospitals. The azole susceptibilities were assessed on the basis of the species-specific CBPs and ECVs. RESULTS: Of the 341 BSIs of 3 common Candida species (i.e., C. albicans, C. tropicalis, and C. parapsilosis), 0.3% and 0.9%, 0.0% and 1.5% of isolates were categorized as fluconazole and voriconazole resistant according to the CLSI and EUCAST CBPs, respectively. Of 423 total BSIs, 1.4% and 2.6% had fluconazole minimum inhibitory concentrations (MICs) exceeding the ECVs according to the CLSI and EUCAST, respectively; 1.0% and 2.1% had voriconazole MICs exceeding the ECVs according to the CLSI and EUCAST, respectively. Categorical agreement between the methods using ECVs was 98.3% for fluconazole and 98.3% for voriconazole. CONCLUSIONS: The EUCAST and CLSI methods using ECVs provide highly concordant results. Moreover, non-wild-type isolates with possibly acquired azole resistance were rare among the BSIs of 5 common Candida species in Korea.

Autoantibodies with Mimicking Specificity Detected by the Dilution Technique in Patients with Warm Autoantibodies

BACKGROUND: The aim of this study was to investigate the frequency of autoantibodies with mimicking specificity by using the dilution technique, to assess the usefulness of the combination of the dilution technique and red blood cell (RBC) phenotyping, and to establish a pre-transfusion testing algorithm in patients with warm autoantibodies. METHODS: Serum samples from 71 patients with warm autoantibodies were tested using the dilution technique. Among them, 25 samples were adsorbed with allogeneic ZZAP (a combination of dithiothreitol and enzyme) or polyethylene glycol (PEG) and their RBC phenotypes were determined. Thirty-nine patients were transfused with our pre-transfusion testing algorithm using a combination of dilution technique and RBC phenotyping. RESULTS: Autoantibodies with mimicking specificity were detected by the dilution technique in 26.8% (19/71) of the patients and most of them were directed against Rh system antigens. The agreement of the results obtained with the dilution technique in combination with RBC phenotyping and those from ZZAP or PEG adsorption was 100% (18/18) in patients who have autoantibodies with mimicking specificity and/or alloantibodies. No clinical symptoms indicating severe acute or delayed hemolytic transfusion reactions were reported in the 39 patients transfused with our pre-transfusion testing algorithm. CONCLUSIONS: Autoantibodies with mimicking specificity detected by the dilution technique in patients with warm autoantibodies are relatively frequent, can be discriminated from alloantibodies by employing a combination of dilution technique and RBC phenotyping, and might not appear to cause severe acute or delayed hemolytic transfusion reactions.

Comparison between V-Tubes and BD Vacutainer Tubes for Use in Laboratory Tests

BACKGROUND: Vacuum tubes are widely used in clinical laboratories for routine tests. We compared a newly developed V-tube (AB Medical, Korea) and BD tubes (BD, USA) in common clinical assays, i.e., hematological, chemical, and immunological tests. METHODS: In total, 100 volunteers comprising 79 patients and 21 healthy volunteers were recruited and peripheral blood samples were collected with 2 brands of EDTA tubes and serum-separating tubes (SSTs). EDTA-tube samples were evaluated using 16 routine hematological tests. The SST samples were analyzed for 32 routine chemical parameters and 3 thyroid hormones. The results were statistically analyzed using the paired t-test and Bland-Altman plot. In addition, the stability of each analyte in 2 brands of vacutainers was evaluated. The results of the hematological tests at t=0 hr were compared with those at t=72+/-2 hr, and the results of the chemical parameters and thyroid hormones at t=0 hr were compared with those at t=72+/-2 hr and t=168+/-2 hr for each tube. RESULTS: Paired t-test analysis revealed that the test results of 16 routine hematological parameters, 32 routine chemical parameters, and 3 thyroid hormones showed clinically allowable differences between the 2 brands of vacuum tubes (t=0 hr). The results obtained when using V-tubes showed a statistically significant correlation with those obtained when using BD tubes. The stability of each analyte was similar in both vacuum tubes. Except for 10 parameters (white blood cell count, mean corpuscular volume, basophils [%], mean corpuscular hemoglobin concentration, monocytes [%], phospholipid, sodium, potassium, chloride, and free T4), all parameters showed significant but clinically allowable differences with regard to storage duration. CONCLUSIONS: The newly developed V-tube vacutainers provide a suitable alternative to BD tubes in common clinical laboratories.

Ex vivo Expansion of Human Natural Killer Cells from Blood Retained in a Disposable Platelet Apheresis Set / 대한수혈학회지

BACKGROUND: Natural killer cells expanded from human peripheral blood (PB) have been used in cancer immunotherapy research. Although most research teams have access to human PB, it is necessary to find a source of blood that can be easily obtained. We have tested the possibility of using blood retained in a disposable platelet apheresis set as an alternative source, with special interest in expansion of NK cells for use in cancer immunotherapy research. METHODS: For expansion of NK cells, peripheral blood mononuclear cells (PBMCs) were isolated from an MCS+ platelet apheresis kit (Haemonetics, Braintree, USA) and PB from the same donor (n=7) and co-cultured with 100-Gy gamma ray-irradiated K562 cells expressing the 4-1BB ligand and membrane-bound IL-15 for three weeks in RPMI1640 medium in the presence of IL-2 and IL-15. Cytotoxicity was measured using WST-1 at 1:1, 2:1, and 4:1 effector-to-target (E:T) ratios for a period of four hours. RESULTS: Mean rate of expansion of NK cells was 1,097-fold and their purity was 94.4% from blood retained in a disposable platelet apheresis set; mean rate of expansion of NK cells was 953-fold and their purity was 92.0% from PB after a period of three weeks. No differences in cytotoxicity against K562, 697, Raji, and RPMI8226 were observed between NK cells expanded from two blood sources. CONCLUSION: Blood retained in a disposable platelet apheresis set is a useful and convenient source for expansion of NK cells for use in cancer immunotherapy research.

Auto-antibody Showing Anti-Fy(b) Specificity as Proven by the Dilution Method in the Presence of Warm Autoantibodies: A Case Report / 대한수혈학회지

Several approaches have been introduced to detect allo-antibodies in the presence of warm auto-antibodies, and these methods include warm autoadsorption, cysteine-activated papain and dithiothreitol (ZZAP), and polyethylene glycol (PEG) and dilution of the patient's serum. Among them, the dilution technique is a simple and rapid method. During pretransfusion testing of a 33 year-old systemic lupus erythematosus (SLE) patient with warm auto-antibodies, antibody identification was done by the dilution technique with using serum diluted 1-in-8. The patient demonstrated an anti-Fy(b) pattern of reactivity in his sera. Contrary to our expectations, the phenotype of the erythrocytes was Fy(a+/b+) and the genotype, as assessed by performing PCR-restriction fragment length polymorphism (RFLP), was FY*A/FY*B. These results suggest that the antibody is an autoantibody showing anti-Fy(b) specificities. An antibody identification test using undiluted serum showed the same result when 40 days had passed. We report here on a case with auto-anti-Fy(b) proven by the dilution method in the presence of warm autoantibodies.

New Variant of O02 Allele Found in the Family of Cis-AB: Report of Three Cases in a Family / 대한수혈학회지

In preoperative ABO typing, we observed an ABO discrepancy in a 61 year-old patient with A2B3 phenotype. Standard serologic tests for the ABO blood group phenotypes and ABO gene direct sequencing for the exons 6 and 7 were done as part of the patient's family study. We found that the patient's genotype was identical to cis-AB01/O02, except for a 703 G>A polymorphism at exon 7. An allele-separation by cloning and subsequent sequencing of the heterozygote was carried out. We identified a novel O02 variant allele characterized by a 703 G>A polymorphism in the patient and in her 2 daughters.