Friday, June 3,2011 Aaron T. Gerds, MD HEMATOLOGY FELLOW S CONFERENCE

Transcription

1 Friday, June 3,2011 Aaron T. Gerds, MD HEMATOLOGY FELLOW S CONFERENCE

2 Admit H&P - September 25, year old man with a history of diabetes, hypertension, and chronic anemia who has felt weak since May. Shortness of breath while walking to his car or up a flight of stairs. Guiac + stool

3 Admit H&P - September 25, 1998 \ 3.5 / / / 13.5 \ \ MCV 70.7 MPV 10.2 Haptoglobin 164 Coombs Neg MCH 16.8 Segs 72% LDH 134 T Bili 0.6 RDW 19.7 Lymph 12% B aptt 22.6 Retic 3.6% Mono 13% Folate 15.9 INR 0.97 Eos 2% Baso 1% Ferritin 3 Iron 15 TIBC 458 EKG showed sinus tachycardia, with no ST changes. Previous CT chest and abdomen which showed hepatosplenomegaly and a 1.0 cm nodule in the right upper lobe (6/1998)

4 Hospital Course Transfused 9 units of PRBC s Colonoscopy was negative Hematology consult Severe iron deficiency anemia He was discharged home to be followed up with outpatient colonoscopy and EGD

5 November 4, 2004 PCP initial visit Came to re-establish care with the VA I need a couple of transfusions. I get transfused every 2 weeks for acute leukemia. I have been going to St. Mary s, but all the aid stopped and I can t afford it anymore. Chief complaint was lightheadedness. He was then sent to the ER and admitted

6 Over the Past 6 Years Myelodysplatic y syndrome He was given the options of bone marrow transplant, chemotherapy, or blood transfusions Weekly transfusions x3 years Most recent marrow was 2/2001 was consistant with MDS, normal cytogenetics and flow cytometry. Iron deficiency due to chronic gastritis Tagged RBC scan (2/2001) showed no active bleeding Colonoscopy and EGD both completed within last 2 years which were normal per patient Iron stores absent on marrow biopsy 2/2001

7 Admit H&P November 4, 2004 \ 6.2 / INR / aptt Alk Phos 78 / 20.7 \ Neut 64% \ AST 10 Lymph 17% ALT 31 MCV 64.3 Mono 11% TIBC 347 T Bili MCH 19.2 Eos 6% Iron 5 Alb 3.2 RDW 23.0 Baso 1% Ferritin 2 A1c 8.9 MPV 13.5 Retic 25% 2.5% B LDH 119 IgG-K 1.2 g ARC 78K Folate 1012 Haptoglobin 116

8 Achtung Baby! Clinically significant antibodies: Anti-E, Anti-c, cantik Anti-K and Anti-Jk(a). At this point he had received at least 181 units of packed red cells over last 4 years!

9 Against All Odds ABO Blood Group Do the math Donors with type O or A = 85% RH Blood Group Donors that are D(+) or D(-) = 100% Donors that are E and c negative = 17.6% Kell Blood Group Donors that are K negative = 91% Kidd Blood Group Donors that are Jk(a) negative = 23% 0.85 x 1.0 x x 0.91 x 0.23 = % donors will be serologically compatible ~ 1 out of 32 units the blood bank has on the shelf

10 RBC Antigens and Alloantibodies

11 Williams' Hematology, 8th ed, McGraw-Hill, New York, 2005.

12 Classification of Red Cell Antigens Blood Groups - 29 Blood Group Systems - Include ABO, Rh, and Kell blood Groups Collections 7 Collections of antigens Series 22 antigens in the 700 series 11 antigens in the 901 series Vox Sang 2004; 87:

13 Our Patient s Antibodies Expected antibody Anti-B (ABO blood group) Unexpected antibodies Rh (Anti-E, Anti-c) Kell(Anti-K) Kidd (Anti-Jk a )

14 ABO Blood Group System When an individual lacks the A and/or B antigen

15 Expected Natural Antibodies E. coli serotype 086:B7 has a B like antigen Exposed 16 subjects by ingestion or inhalation Measured pre and postexposure p anti B titers 1/3 had a significant increase in the titer of anti B Anti B response was strongest in those who produced high titer antibodies to E. coli. Reported cases of A & O platelet donors taking probiotics, high anti B titers, resulting in HTR s in B patients Springer and Horton, J Clin Invest. 1969;48: Daniel-Johnson J, et al., Transfusion. 2009;49:

16 Antigens Immunogenicity What about the unexpected antibodies? Estimate of immunogenicity i i by comparing The actual frequency with which particular alloantibodies are encountered with The calculated frequency of the opportunity for immunization Giblett ER, Transfusion. 1961;1:233-8.

17 Antigens Immunogenicity Red Blood Cell Antigen Immunogenicity Antigen A, B 100 Rh(D) 80 K 10 c, E 3 Fy(a) 0.4 Jk(a) 0.1 Relative immunogenicity Mollison's Blood Transfusion in Clinical Medicine, 11th ed. Wiley-Blackwell, Oxford, Giblett ER, Transfusion. 1961;1:233-8.

18 Immune Status # of Exposures How Different? Alloantibody Production Genetic Predisposition

19 How Different? Disparity with respect to race and red cell phenotype between SSC and donor population Up to 95% European decent that have a red cell antigen phenotype (Rh, Duffy, Kell, and Kidd) that are not common in the African American population Vichinsky et al., N Engl J Med. 1990;322:

20 Vichinsky et al., N Engl J Med. 1990;322:

21 Vichinsky et al., N Engl J Med. 1990;322:

22 Vichinsky et al., N Engl J Med. 1990;322:

23 How Different? Calculated that a African American recipient 33% chance of compatibility for these antigens with any individual froma same ethnicity ethnicity donor pool 3% chance of matching with someone from a typical urban donor pool (90% European, 10% African ethnicity) 1% chance of matching with someone from a 100% disparate ethnicity donor pool Orlina et al., J Clin Apheresis 1991;6:

24 Immune Status 24 Rh(D ) patients undergoing OLT who received a mean of 13 units of Rh(D ) blood peri operatively. None developed anti D antibodies. Rates of alloantiboides are lower in chronically transfused patients with CLL as compared to to others High incidence of red cell alloantibodies in patients with autoimmune disorders Youan et. al., Transfusion 2008;48:2653. Blumberg et al., Vox Sang 1983;44: Mollison s Blood Transfusion in Clinical Medicine. 11 th ed. Blackwelll, London, 2005.

25 Number of Exposures Vichinsky et al., N Engl J Med. 1990;322:

26 Genetic Predisposition When adjusted for ethnicity, immune status, and number of exposures there are patients who make antibodies and some who don t. Subpopulaton of responders who respond to RBC antigens at a much higher rate than the general population. lti Higgins i et al measured Alloimmunization rates of all transfused patients over a 2 year period Higgins et al., Blood 2008;112:

27 Number of Exposures Higgins et al., Blood 2008;112:

28 Responders Only Taking only those that made alloantibodies Worked under the assumption that alloantibody formation has no memory The probability that a patient with 2 antibodies will make a 3 rd is the same as a patient with 8 making a 9 th Fit a geometric probability distribution, (1 p)p n The frequency of acquiring ii an additional antibody is 30% If 30% of responders are alloimmunized with transfusion, and 4% of all patients transfused are alloimmunuzed, then 13% of patients must be responders. Higgins et al., Blood 2008;112:

29 Responders Ifa responder trait was present 100% of patients with The dramatic alloantibodies increase there in the would risk be of a 8 fold increase in alloimmunization the prevalence of in this trait subpopulation over those appears without to alloantibodies be largely genetically (100%/13%) determined because it is independent of common disease states, patient age, or number of alloantibodies already formed, and only weakly dependent on transfusion count. Higgins et al., Blood 2008;112:

30 Back to the Case Transfused 3 units PRBC s Started on IV iron Bone marrow biopsy was done on the day of discharge, and the features seen were most consistent with iron deficiency anemia Repeat endoscopy showed multiple AVM s

31 March 21,2005 Call into GMC Nurse My y hand from my wrist to my finger tips went completely numb. But if I cut my finger, I would feel it. Sudden onset of left wrist weakness the night before

32

33 Pulmonary Nodule: What to do next? 2.5 Pulmonary Nodule Size (cm)

34

35 Back to Our Patient Pulmonary AVM Family history Epistaxsis i Upper and lower GI AVM s resulting in severe IDA And on careful examination we see

36 Back to Our Patient

37 HHT Diagnosis International consensus diagnostic criteria: Spontaneous and recurrent epistaxis Multiple mucocutaneous telangiectasias Visceral involvement (eg, gastrointestinal, pulmonary, cerebral, or hepatic AVMs) A first-degree relative with HHT 0-1 unlikely, 2-3 suspected, 4 definite Can be confirmed with genetic testing Am J Med Genet 2000 Mar 6;91(1):66-7.

38 Achtung Baby! Clinically significant antibodies: Anti-E, Anti-c, cantik Anti-K and Anti-Jk(a). At this point he had received at least 181 units of packed red cells over last 4 years!

39 Immune Status # of Exposures How Different? Alloantibody Production Genetic Predisposition

40 Dr. Delaney Dr. Gernsheimer Dr. Blau Thank You

41

42 Problems with alloimmunization Prolonged time to finding compatible blood products can endanger patient s need for blood Hours to days to never Delayed hemolytic transfusion reactions Acute transfusion reactions Long laboratory work ups Costly Potential for future hemolytic disease of the newborn in women of childbearingpotential

43 Provide RBC with higher antigen match? Immune Status # of Exposures How Different? Alloantibody Production Genetic Predisposition Others to consider 1. Pts with 1 st antibody 2. Females pregnancy potential 3. Chronic transfused 4. Everyone? Standard (all patients, 4%) ABO, RhD Standard (sickle cell disease patients, 20 50%) ABO, RhD, RhCE, K (<10%)

44 Inventory / Phenotype problem ABO D c C e E K Fya Fyb Jka Jkb S s % Blood donors AA O % Cauc O % PSBC: red cell components inthe inventory PSBC: 4,300 red cell components in the inventory 10% (450 components) typed for 1 antigen 75% (337 components) typed for 11 antigens

45 Genotyping for blood group antigen phenotype prediction

46 Genotyping: Blood groups Pro No fresh red cells needed Avoid tedious procedures in red cell serology lab No antisera available Dombrock Learn genetic alterations that are clinically significant Con Expensive (+/-) Relatively slow (+/-) Phenotype doesn t always correlate with genotype (+/-) Science evolving

47 Approach: Genotyping blood groups Gene arrays or Luminex based platforms Immucor Progenika GenProbe PCR SSP & Real time PCR (quantitative) Commercial kits Home brew RFLP, homebrew DNA or RNA sequencing Donors

48 Conclusions For blood transfusion to move toward higher match for other patient groups, significant barriers remain Genomic technology not high through put enough Serological typing (tech) costly and antisera not available Regulatory requirements, FDA needs to approve genotyping to label units with molecular typing Cost must still come down In current economic climate, there is no tolerance for increasing i the cost of blood