Two Cases of Anti-D Alloimmunization in D-Negative Thai Patients as a Result of the Asian-Type DEL on Transfused Red Cells.

Introduction: DEL is known to be one of the weakest D variants, which can be detected by the adsorption-elution technique or by molecular study. Currently, in Thailand, we do not routinely test for DEL variants serologically or genetically among serologic RhD-negative blood donors. Case Presentation: We reported 2 cases of alloimmunization after transfused with Rh DEL, RHD*DEL1 allele, in the Thai population. The first case was a 73-year-old male with anemia who presented with post-cardiac arrest and septic shock. The patient was group B, RhD-negative, and was transfused with RhD-negative red blood cells (RBCs). Antibody screening and identification found that the patient developed anti-D and anti-Mia during the admission course. The second case was a 38-year-old woman with pseudomyxoma peritonei who developed anti-D after receiving four units of RhD-negative RBCs during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy. Both patients did not receive anti-D immunoglobulin and had no previous history of anti-D detection. We retrospectively investigated and found two units of RHD*DEL1 among the RBCs transfused to these patients. Discussion: Previous reports of several cases of anti-D alloimmunization in RhD-negative recipients transfused by RHD*DEL1, an Asian-type DEL, are limited only to East Asia. We first identified 2 patients with anti-D alloimmunization after receiving the RHD*DEL1 RBCs in the Thai population. This raises concern about Rh DEL screening among D-negative Thai blood donors and whether to remove DEL units from the D-negative inventory to improve patient safety.

Evaluation of the effectiveness of platelet crossmatching by the solid-phase red cell adherence assay in adult patients of a tertiary care hospital in Thailand: A retrospective study.

Background and Aims: Platelet transfusion refractoriness is well aware to be associated with poor clinical outcomes. Patients with the alloantibody causing refractoriness required cross-matched compatible products to improve the platelet number. This study aims to evaluate the effectiveness and availability of platelet crossmatching provided by the solid-phase red cell adherence (SPRCA) technique in the context of a tertiary university hospital. Methods: A retrospective chart review was performed of the records of 214 patients with platelet refractoriness in Siriraj Hospital, a tertiary university hospital in Thailand, between January 1, 2017, and December 31, 2020. Results: The SPRCA technique successfully provided cross-matched compatible platelets to 114 patients (69.7%). Platelet crossmatching significantly improved the platelet counts, as shown by the increased 1- and 24-h corrected-count increments (p< 0.0001). No acute transfusion reactions were observed in these patients. Of the 114 patients who received cross-matched platelets, 82 patients (71.9%) survived at 30-day posttransfusion; whereas, 16 patients (14.0%) died within 7-day posttransfusion. Conclusion: The SPRCA method can provide a high availability rate of cross-matched platelets, which is effective at stopping and preventing clinical bleeding conditions. This method is appropriate to apply for platelet crossmatching in the context of a hospital blood bank.

Prevalence of G6PD deficiency in Thai blood donors, the characteristics of G6PD deficient blood, and the efficacy of fluorescent spot test to screen for G6PD deficiency in a hospital blood bank setting.

BACKGROUND: Transfusion of blood from glucose-6-phosphate dehydrogenase (G6PD) enzyme deficient donors could cause a potentially unfavorable outcome, especially in newborns and those with hemoglobinopathies. AIMS: To determine the prevalence of G6PD deficiency in Thai blood donors, the characteristics of G6PD deficient blood, and the efficacy of fluorescent spot test (FST) to screen for G6PD deficiency in a hospital blood bank setting. METHODS: Blood samples were obtained from 514 Thai blood donors who donated blood at Siriraj Hospital (Bangkok, Thailand) during December 2020-February 2021. G6PD deficiency status was screened using FST, and in vitro hemolysis of red blood cell parameters of G6PD deficient blood units was compared with those of normal control units at different time points during 35 days of refrigerated storage. RESULTS: The prevalence of G6PD deficiency was 7.59% (35 [8.73%] males, 4 [3.54%] females). The sensitivity of FST was 100% (95% confidence interval [CI]: 90.97-100%), and the specificity was 99.58% (95%CI: 98.49-99.95%). In vitro hemolysis was not significantly different between G6PD deficiency and normal controls. CONCLUSION: The prevalence of G6PD deficiency in this study was 7.59%. FST was demonstrated to be an effective and reliable method for G6PD deficiency screening among Thai blood donors in a hospital blood bank setting.

Quantitative proteomics of plasma vesicles identify novel biomarkers for hemoglobin E/ß-thalassemic patients.

Hemoglobin E (HbE)/ß-thalassemia has a wide spectrum of clinical manifestations that cannot be explained purely by its genetic background. Circulating extracellular vesicles (EVs) are one factor that likely contributes to disease severity. This study has explored the differences in protein composition and quantity between EVs from HbE/ß-thalassemic patients and healthy individuals. We used tandem mass tag labeling mass spectrometry to analyze the EV proteins isolated from the plasma of 15 patients compared with the controls. To reduce biological variation between individuals, the EV proteins isolated from randomly assigned groups of 5 HbE/ß-thalassemic patients were pooled and compared with 5 pooled age- and sex-matched controls in 3 separate experiments. Alpha hemoglobin-stabilizing protein had the highest fold increase. Catalase, superoxide dismutase, T-complex proteins, heat shock proteins, transferrin receptor, ferritin, and cathepsin S were also upregulated in thalassemic circulating EVs. Importantly, haptoglobin and hemopexin were consistently reduced in patients' EVs across all data sets, in keeping with the existing hemolysis that occurs in thalassemia. The proteomic data analysis of EV samples isolated from 6 individual HbE/ß-thalassemic patients and western blotting results corroborated these findings. In conclusion, we have successfully identified consistent alterations of protein quantity between EVs from HbE/ß-thalassemic and healthy individuals. This work highlights haptoglobin, hemopexin, and cathepsin S as potential clinically relevant biomarkers for levels of hemolysis and inflammation. Monitoring of these plasma proteins could help in the clinical management of thalassemia.

Incidence and risk factors of bone marrow involvement by non-Hodgkin lymphoma.

BACKGROUND: Since trephine bone marrow biopsy is an invasive procedure, the identification of a subgroup of patients with Non-Hodgkin lymphoma (NHL) who have a minimal risk of bone marrow involvement would be helpful. This study is aimed to determine the incidence of bone marrow involvement (BMI) by NHL and the predictors of no BMI to not only avoid this invasive procedure but also decrease the cost of investigation. MATERIAL AND METHOD: Data from 320 patients with NHL at division of hematology between January 2008 and June 2009 were reviewed and analyzed. RESULTS: The cell types of NHL were classified as B-cell in 283 patients (88.4%), T-cell in 37 patients (11.6%) and incidence of BMI is 24.4% and 18.9% in B- and T-cell, respectively. Factors significantly associated with BMI in univariate analysis were the hepatic and splenic involvement (p = 0.03 and < 0.01, respectively), significant weight loss (p = 0.02), presence of lymphadenopathy (LN) below diaphragm (p = 0.02), anemia (p = 0.001), low percent of blood neutrophil (p < 0.001), high percent of blood lymphocyte (p < 0.001), low absolute neutrophil count (p = 0.002), high absolute lymphocyte count (p = 0.045), low platelet count (p < 0.001), high LDH (p = 0.026), and high alkaline phosphatase (p = 0.020). On the multivariate analysis, factors associated with BMI included LN below diaphragm, anemia, low percent of blood neutrophil and low platelet count. Excluding Burkitt lymphoma and mantle cell lymphoma, NHL patients with no LN below diaphragm, no hepatic & splenic involvement, no significant weight loss, hemoglobin (Hb) >11 g/dL and platelet > 150,000/uL had BMI in 3/78 (3.8%). CONCLUSION: The incidence of bone marrow involvement in NHL is 23.8%. Excluding Burkitt lymphoma and mantle cell lymphoma, NHL patients with no LN below diaphragm, no hepatic & splenic involvement, no significant weight loss, Hb > 11 g/dL and platelet > 150,000/uL had low risk of BMI.