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.

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.