Transfusion support in hematopoietic stem cell transplantation

Transfusion support for hematopoietic stem cell transplantation (HSCT) is an essential part of supportive care, and compatible blood should be transfused into recipients. As leukocyte antigen (HLA) matching is considered first and as the blood group does not impede HSCT, major, minor, bidirectional, and RhD incompatibilities occur that might hinder transfusion and cause adverse events. Leukocyte reduction in blood products is frequently used, and irradiation should be performed for blood products, except for plasma. To mitigate incompatibility and adverse events, local transfusion guidelines, hospital transfusion committees, and patient management should be considered.

Causes of Positive Pretransplant Crossmatches in the Absence of Donor-Specific Anti-Human Leukocyte Antigen Antibodies: A Single-Center Experience

Pretransplant crossmatch (XM) testing is widely used for detecting preformed donor-specific antibodies (DSAs) against human leukocyte antigen (HLA). However, in some cases, there is a positive XM result in the absence of HLA-DSAs, the cause of which was rarely identified. We reviewed the causes of sequential positive XM results at a single center and analyzed the presence of non-HLA antibodies in patients with an unexplained positive pretransplant XM result. Among 251 patients with T-cell/B-cell complement-dependent cytotoxicity (CDC) or flow cytometric crossmatch (FCXM) positivity, HLA-DSAs were confirmed in 88 (35.1%) by a single antigen bead (SAB) assay, 150 (59.8%) used rituximab (anti-CD20), and 13 (5.2%) had neither HLA-DSAs nor a desensitization history. Anti-angiotensin II type 1 receptor IgG and 33 non-HLA antibodies were tested in the 13 patients with an unexplained positive pretransplant XM result, and more than one non-HLA antibody were revealed in all these patients; 11 patients had non-HLA antibodies reported to be associated with graft rejection, and two patients experienced rejection episode after kidney transplantation. Our study suggests considering non-HLA antibodies testing when a CDC or FCXM test is positive without a definite cause. Assessing non-HLA antibodies might be useful for interpreting XM results and evaluating immunologic risk in transplant recipients.

Clinical Validity of Next-Generation Sequencing Multi-Gene Panel Testing for Detecting Pathogenic Variants in Patients With Hereditary Breast-Ovarian Cancer Syndrome

BACKGROUND: Hereditary breast and ovarian cancer syndrome (HBOC) is caused by pathogenic variants in BRCA and other cancer-related genes. We analyzed variants in BRCA gene and other cancer-related genes in HBOC patients to evaluate the clinical validity of next-generation sequencing (NGS) multi-gene panel testing. METHODS: The BRCA1/2 NGS testing was conducted for 262 HBOC patients. Multiplex ligation-dependent probe amplification and direct Sanger sequencing were performed for confirmation. Multi-gene panel testing was conducted for 120 patients who did not possess BRCA1/2 pathogenic variants but met the National Comprehensive Cancer Network criteria. RESULTS: Pathogenic variants in BRCA1/2 were detected in 30 HBOC patients (11.5%). Additionally, four out of the 120 patients possessed pathogenic variants by multi-gene panel testing (3.3%): MSH2 (c.256G>T, p.Glu86*), PMS2 (c.1687C>T, p.Arg563*), CHEK2 (c.546C>A, p.Tyr182*), and PALB2 (c.3351-1G>C). All the four patients had a family history of cancer. CONCLUSIONS: Multi-gene panel testing could be a significant screening tool for HBOC patients, especially for those with a family history of cancer.

Performance Evaluations of the Abbott Alinity m Assay in Comparison with the Abbott m2000Assay for Hepatitis B and Hepatitis C Viruses

Methods@#The precision, linearity, limit of detection (LOD), correlation with the Abbott m2000 assay, and interference were evaluated. @*Results@#The within-laboratory standard deviation ranged from 0.106 to 0.137 log IU/mL for HBV and from 0.073 to 0.097 log IU/mL for HCV, which was lower than the manufacturer’s specification of 0.25 log IU/mL, indicating good precision. Linearity was observed from 1.14 to 8.14 log IU/mL for the HBV assay and from 1.09 to 7.09 log IU/mL for the HCV assay. The LODs of HBV and HCV were 10 and 6.39 IU/mL, respectively, which were equivalent to or better than those claimed by the manufacturer. For comparative evaluation between Alinity m and m2000 assays, 142 HBV and 70 HCV samples were tested. The correlation test revealed a strong correlation for both markers, and the Passing–Bablok regression analysis did not reveal any significant deviation. @*Conclusions@#The Alinity m assay demonstrated excellent performance for HBV and HCV quantifications with reduced hands-on time and a randomaccess format.

Enumeration of CD34-positive Stem Cells Using the ADAMII Image-based Fluorescence Cell Counter

BACKGROUND: It is very important to accurately enumerate CD34-positive (CD34+) cells for successful hematopoietic stem cell transplantation (HSCT). We evaluated the ability of the newly developed image based-immunofluorescence cell counter ADAMII (NanoEntek, Seoul, Korea) to enumerate CD34+ cells, which was improved through simultaneous CD45 analysis. METHODS: We enumerated CD34+ cells with ADAMII using 19 peripheral blood (PB) and 91 leukapheresis samples from HSCT donors. Analytical performance, including precision and linearity, was analyzed, and sample stability during storage was evaluated. Viable CD34+ cell count (vCD34) and viable CD45+ cell count (vCD45) and the percentage of viable CD34+ cells among viable CD45+ cells (CD34/CD45) as measured by ADAMII were compared with the corresponding values from two flow cytometry assays, using regression analysis. RESULTS: ADAMII demonstrated acceptable precision, as CV values of vCD34 from six samples with different counts were all < 10% (range: 3.49–9.51%). CV values of the vCD45 and CD34/45 ranged from 4.03% to 9.67% and from 2.48% to 10.07%, respectively. The linearity of vCD34 showed an excellent R 2 value (0.99) when analyzed using the intended count and flow cytometry data. The ADAMII and two flow cytometry-based assays generated very similar data for the PB and leukapheresis samples. CONCLUSIONS: ADAMII demonstrated excellent performance for use as a routine clinical assay in terms of CD34+ cell enumeration from PB and leukapheresis samples. Moreover, it could be used as a point-of-care-test for determining mobilization time and predicting an adequate apheresis stem cell product.

Evaluation of the Automated Immunohematology Analyzer DAYMATE M

BACKGROUND: An automated immunohematology analyzer, DAYMATE M (DAY Medical, Switzerland), has been recently developed. The potential of this analyzer to improve test results has been evaluated. METHODS: A total of 300 blood samples from Seoul St. Mary's hospital and Incheon St. Mary's hospital were tested for ABO and RhD typing. In addition, 336 antibody screening test (AST) samples and 82 patients treated with hematopoietic stem cell transplantation (HSCT) were included. AST results by DAYMATE M were compared with those obtained by a manual method using DS-Screening II (Bio-Rad Laboratories, Switzerland) and red blood cells from Selectogen (Ortho-Clinical diagnostics Inc., USA). RESULTS: Of the 300 patients enrolled, 87, 73, 79, and 61 had type A, B, O, and AB blood, respectively. The concordance rate was 99.9% for cell typing and 97.0% for serum typing. One discordant case was classified as type B instead of AB, and six discordant serum-typing cases were type A, but classified as type AB. Among the 336 AST samples, the concordance rate was 93.2%. From 136 positive cases, six were discordant. Within the 82 HSCT-treated patients, the concordance rate for ABO blood typing was 92.2%. Among the six discordant cases, DAYMATE M typed four cases as donor type where the standard method typed them as the recipient blood type. CONCLUSIONS: The DAYMATE M automated immunohematology analyzer performs reliably for ABO and RhD typing, as well as for ASTs and on samples from patients treated with HSCT.

Pseudo gray platelet syndrome: the first case report in Korea

No abstract available.