Transfusion Case Study September 2011

1. Transfusion Case StudySeptember 2011 By Jennifer Jeffrey

2. Rh Nomenclature

3. Case Study Background: • Female Patient, DOB: 31.05.1946 attends WAE in June 2008 with a GI Bleed and Hb of 6.7g/dL. She types as: • Group: A+ • Antibody Screen: Negative • She is transfused 2 units of A Negative red cells - rr (cde/cde or C- c+ E- e+) and 2 units of A Positive red cells - R1R1 (CDe/CDe or C+ c- E- e+). • She is tested, four days later. She types as: • Group: A+ • Antibody Screen: Negative • Group Manually Edited. (Dual population of RhD+ and RhD- red cells due to Tx of Rh- red cells) • We next see her 2 years later, 08th June 2010 with an Hb of 6.8g/dL. She types as: • Group: A+ • Antibody Screen: Negative • She is transfused 2 units of A+, one phenotype R1r (CDe/cde or C+ c+ E- e+) and one phenotype R2r (cDE/cde or C- c+ E+ e+).

4. Further Background: • 20 days later on 28th June, her Hb is 6.1g/l and two further units are requested. She types as: • Group: A+ • Antibody Screen: Positive • An antibody panel is performed, along with a phenotype and DAT (Direct Antiglobulin Test). Provide: • An antibody interpretation • A probable Rh genotype shorthand interpretation • List any further testing/actions you would perform/take

6. Antibody interpretation – anti-c detected by IAT & enzyme technique. • A probable Rh genotype shorthand interpretation – R1R2 however, 20 days ago red cells were transfused with a combined phenotype of C+ c+ E+ e+. Transfused red cells are being phenotyped, this is not the patients phenotype!! • What is the significance of the DAT result – IgG(4+)??

7. DAT • If positive for IgG, IgG antibodies have bound to the patients red cells in vivo. • If DAT positive for IgG only, complement has not been activated and the red cells are removed from the circulation via macrophages, predominantly in the spleen.

8. The presence of C3d on the red cell surface indicates complement has been activated. • In what conditions is the DAT IgG positive? • Auto Immune Haemolysis – Haematological disorder (CLL/Myeloma) or drug induced. • Allo Immune Haemolysis – Haemolytic disease of the foetus/newborn or a transfusion reaction.

9. Back to our patient… • Due to the phenotype and DAT results, this was reported as an auto anti-c • Auto antibodies can appear to ‘prefer’ Rh specificities, usually ‘anti-e like’ or ‘anti-E & anti-D like’. Only do they very, very rarely resemble ‘anti-c like’ or ‘anti-C like’ antibodies. Any auto antibodies should be confirmed by Red Cell Immunhaematology (RCI) at NHSBT.

10. Back to the all important background…… • June 2008 • Group: A+ • Antibody Screen: Negative • She is transfused 2 units of rr (cde/cde) A Negative red cells and 2 units of R1R1 (CDe/CDe) A Positive red cells. = sensitisation event • We next see her 2 years later, 08th June 2010 • Group: A+ • Antibody Screen: Negative = Anti-c below detectable limits • She is transfused 2 units of A+, one phenotype R1r (CDe/cde) and one phenotype R2r (cDE/cde). • 20 days later on 28th June, her Hb is 6.1g/l and two further units are requested. She types as: • Group: A+ • Antibody Screen: Positive = Anti-c produced in secondary immune response, risen to detecable levels and causing destruction of transfused red cells in delayed transfusion reaction – thankfully mild!

11. List any further testing/actions you would perform/take • Inform the ward, haematology clinician and transfusion practioner that possible suspected delayed transfusion reaction. • IMPORTANT – log all conversations, times and names of those contacted. Record on APEX if appropriate. • Contact NHSBT for historically transfused unit phenotypes. • Exclude the presence of any masked antibodies. • The antibody panel result you would enter onto APEX • Anti-c detected by IAT and enzyme technique. • The SRPAD you would enter onto APEX • Anti-c present. Unable to obtain definitive phenotype due to recent transfusion. Select ABO/Rh compatible, c-, K- units and issue by IAT crossmatch. Initial + date. • Additional: • Record under ‘A’ that a definitive phenotype could not be obtained due to previous transfusion. Record that delayed transfusion reaction suspected and log who has been contacted and when. • Report DAT result under ‘D’.

12. Delayed Transfusion Reactions • Symptoms: • Fall in haemoglobin concentration • Unexpectedly small rise in Hb • Jaundice • Fever • Rarely haemoglobinuria or renal failure. • Investigations: • DAT • FBC + Film • LDH • Renal Profile • Bilirubin • Haptoglobulin • Urinalysis for haemoglobinuria. • Specific treatment is rarely required, although further transfusion may be needed. A report must be made to MHRA Serious Adverse Blood Reactions & Events (SABRE) & Serious Hazards of Transfusion (SHOT).

13. Take home points…. • Always try to account for the presence of an antibody e.g. previous transfusion or pregnancy. Some can be naturally occuring – discuss with senior staff. • A phenotype can only be performed at least 90 days post transfusion. Dual populations indicate transfused red cells! • If the DAT is positive, does the patient have an underlying haematological condition? • If your results don’t add up, discuss with senior staff or contact RCI/NHSBT for advice