Complex Transfusion Management in a Sickle Cell Patient With Anti-Fy3 Alloimmunization: A Case Report.

Fy3 is a high-prevalence red blood cell antigen of the Duffy (Fy) blood group system. Anti-Fy3 antibodies are rare and solely arise in individuals with a Duffy null phenotype (Fy(a-b-)), which is a phenotype that mainly occurs in people of African descent. Clinically, anti-Fy3 antibodies can cause both acute and delayed hemolytic transfusion reactions in adults as well as hemolytic disease in fetuses and newborns. Here, we report the case of a 26-year-old male with sickle cell disease (SCD) and a history of anti-E alloantibodies, who was admitted to the hospital with a vaso-occlusive crisis (VOC) and associated low hemoglobin (Hb) level. For the latter he received one unit of antigen-matched and crossmatch-compatible packed red blood cells (pRBCs) without complications. Ten days later the patient was readmitted with a further VOC and associated low Hb level, again requiring a red cell transfusion. However, no crossmatch-compatible pRBCs could be identified. Laboratory testing demonstrated pan-reactivity with additional reference testing demonstrating the presence of anti-E, anti-Fy3 and anti-Jkb alloantibodies. This case highlights the diagnostic and therapeutic challenges associated with blood transfusion in SCD patients with rare alloimmunization profiles.

Primary IgA-mediated Autoimmune Hemolytic Anemia in an Infant Successfully Treated With Rituximab.

Autoimmune hemolytic anemia (AIHA) is uncommon in the pediatric population and is often associated with an infectious etiology or postvaccination. Mostly, the child presents with a positive direct antiglobulin test. The diagnosis can be challenging, as in our case with an immunoglobulin A-mediated AIHA. In addition to supportive therapy, such as a red blood cell transfusion, steroids are the first choice of treatment. Rituximab, as second-line treatment, can be given in conjunction. We report the first case of immunoglobulin A-mediated AIHA treated with rituximab in the literature.

RHD variants in Flanders, Belgium.

BACKGROUND: D antigen variants may be grouped into partial D, weak D, and DEL types. Cumulative phenotype frequencies of these D variants may approach 1% in certain European regions. Unambiguous and quick identification of D variants is of immediate clinical relevance, with implications for transfusion strategy. STUDY DESIGN AND METHODS: A total of 628 samples with ambiguous serologic results from different immunohematology laboratories throughout the Flanders region, Belgium, were genotyped using a commercially available weak D typing approach. After exclusion of detectable weak D types, molecular RHD exon scanning was performed for the remaining samples, and RHD sequencing was performed in two particular cases. RESULTS: Of all samples investigated, 424 (67.5%) were positive for weak D Type 1, 2, or 3, and 22 cases (3.5%) typed weak D Type 4.0/4.1/4.3, 4.2, 5, 11, 15, or 17. Another 49 (7.8%) samples were partial D variants, with a major proportion being category DVI types (n = 27). One RHD(S103P) sample was identified as high-grade partial D, with DIII-like phenotype and anti-D and anti-C immunization. Additionally, a novel DVI Type 3 (A399T) variant was found. Of the remaining 133 samples mainly tested because of ambiguous serologic D typing results due to recent transfusion, 32 (5.1%) were negative for RHD, and 101 (16.1%) were indistinguishable from wild-type RHD and not investigated further. CONCLUSION: Despite the enormous diversity of RHD alleles, first-line weak D genotyping was remarkably informative, allowing for rapid classification of most samples with conspicuous RhD phenotype in Flanders. The clinical implications are discussed.

Haemostatic changes and acquired activated protein C resistance in normal pregnancy.

Influence of changes in levels of coagulation factors and anticoagulants on acquired activated protein C (APC) resistance were studied in 40 healthy women during normal pregnancy. Factor VIII (FVIII), von Willebrand factor antigen (VWF:Ag), free protein S (FPS) and protein C were determined at 5-13, 14-26 and 27-40 weeks gestation and more than 6 weeks postpartum. APC anticoagulant activity was determined by measuring the activated partial thromboplastin time before and after adding human APC, expressed as the APC-sensitivity ratio (APC-SR). During the second and third gestation trimesters a significant increase (P < 0.05) in FVIII and VWF:Ag levels and a decrease in FPS levels were seen compared with the first trimester. Postpartum FVIII and VWF:Ag levels significantly decreased and FPS levels increased compared with the third trimester. Protein C levels remained unchanged during pregnancy and postpartum. Between increased FVIII and lowered APC-SR a trend of inverse correlation (r = -0.329; P = 0.076) occurred in the second trimester. No correlation was found between APC-SR and FPS or VWF:Ag levels. A remarkable finding is the strong inverse relationship between APC-SR and protein C levels (r