Comparative study of alloimmunization against red cell antigens in sickle cell disease & thalassaemia major patients on regular red cell transfusion

Red cell transfusion represents one of the cornerstones of the chronic management of sickle cell disease, as well as its acute complications. Automated red cell exchange can rapidly lower the number of circulating sickle erythrocytes, without causing iron overload. Here, we describe our experience, having offered this intervention since 2011. A transient reduction in the platelet count by 61% was observed after the procedure. This was not associated with any haemorrhagic complications. Despite exposure to large volumes of blood, the alloimmunisation rate was only 0.027/100 units of red cells. The absence of any iron loading was confirmed by serial Ferriscans, performed over a number of years. However, patients with advanced chronic kidney disease showed evidence of iron loading due to reduced innate haemopoiesis and were subsequently switched to simple transfusions. A total of 59% of patients were on regular automated red cell exchange with a history of recurrent painful crises. A total of 77% responded clinically, as evidenced by at least a 25% reduction in their emergency hospital attendance for pain management. The clinical response was gradual and increased the longer patients stayed on the program. The earliest sign of clinical response was a reduction in the length of stay when these patients were hospitalised, indicating that a reduction in the severity of crises precedes the reduction in their frequency. Automated red cell exchange also appeared to be beneficial for patients with recurrent leg ulcers and severe, drug resistant stuttering priapism, while patients with pulmonary hypertension showed a dramatic improvement in their symptoms as well as echocardiographic parameters.

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Phenotype Matching of Donor Red Blood Cell Units for Nonalloimmunized Sickle Cell Disease Patients: A Survey of 1182 North American Laboratories

Archives of Pathology & Laboratory Medicine ◽

10.5858/2005-129-190-pmodrb ◽

2005 ◽

Vol 129 (2) ◽

pp. 190-193 ◽

Cited By ~ 3

Author(s):

Melanie Osby ◽

Ira A. Shulman

Keyword(s):

Sickle Cell Disease ◽

Blood Cell ◽

Sickle Cell ◽

North American ◽

Red Cells ◽

Red Cell ◽

Cell Disease ◽

Cell Antigen ◽

Red Cell Antigens ◽

Matched Donor

Abstract Context.—The transfusion of donor red blood cell units (RBCs) that lack certain red cell antigens (such as C, E, and K) when the corresponding antigens are absent from the recipient's red cells has been shown to reduce the risk of red cell alloimmunization in sickle cell disease patients. However, data are limited regarding the extent to which transfusion services routinely perform red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients, and then use that information to select donor RBCs lacking 1 or more of the red cell antigens that the patient's red cells do not express. Objective.—To determine the extent to which transfusion services routinely perform red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients, and then use that information to select donor RBCs lacking 1 or more of the red cell antigens that the patient's red cells do not express. Design.—An educational subsection of a College of American Pathologists Proficiency Testing Survey (J-C 2003) assessed transfusion service practices regarding performance of red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients and how transfusion services use this information for the selection of donor RBCs. The data analysis of the survey included 1182 North American laboratories. Results.—Data from 1182 laboratories were included in the survey analysis, of which the majority (n = 743) reported that they did not routinely perform phenotype testing of sickle cell disease patients for antigens other than ABO and D. The other 439 laboratories reported that they did routinely perform phenotype testing of sickle cell disease patients for antigens in addition to ABO and D. The majority of these 439 laboratories (three fourths; n = 330) reported that they used these patient data for prophylactic matching with donor RBCs when sickle cell disease patients required transfusion. When phenotype-matched donor RBCs were used, the antigens most commonly matched (85% of the time) were C, E, and K. Conclusions.—The majority of North American hospital transfusion service laboratories do not determine the red cell antigen phenotype of nonalloimmunized sickle cell disease patients beyond ABO and D. Those laboratories that do determine the red cell phenotype of nonalloimmunized sickle cell disease patients beyond ABO and D most commonly match for C, E, and K antigens when phenotype-matched donor RBCs are used.

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Children with Sickle Cell Disease on Chronic Red Cell Transfusion Experience Fewer Hospitalizations for Acute Vaso-Occlusive Episodes Irrespective of the Indication for Transfusion

Blood ◽

10.1182/blood.v124.21.4282.4282 ◽

2014 ◽

Vol 124 (21) ◽

pp. 4282-4282

Author(s):

Carmen C Wallace ◽

Hilda Mata ◽

Nancy J Wandersee ◽

J. Paul Scott ◽

Amanda M Brandow ◽

...

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Admission Rate ◽

T Test ◽

Acute Chest Syndrome ◽

Red Cell ◽

Cell Disease ◽

Splenic Sequestration ◽

Red Cell Transfusion ◽

The Impact

Abstract While there is strong evidence that chronic red cell transfusion is effective in preventing primary stroke and reducing the risk of recurrent stroke in sickle cell disease (SCD), it is less clear whether chronic transfusions will prevent admissions for other acute vaso-occlusive complications, including pain, priapism and/or acute chest syndrome. To our knowledge, no study to date has investigated the effect of chronic transfusion on the frequency of admissions for acute vaso-occlusive complications in children with all diagnoses of SCD and treated with chronic transfusion for a variety of indications. In addition, this study included a special focus on the effect of chronic transfusion on children who were transfused specifically for recurrent vaso-occlusive episodes. We performed a single-site retrospective chart review. We selected subjects from all children aged 0 to 19 years who were treated (lived in the Milwaukee area) and followed by the Wisconsin Sickle Cell Center at Children’s Hospital of Wisconsin from 1984 to May 2014 (n=695 subjects). Data was extracted from any individual who was enrolled in a chronic transfusion program for a minimum of six months. Data on admissions for painful vaso-occlusive crises, acute chest syndrome (ACS), other SCD complications as well as sickle diagnosis, age at time of transfusion, CBC, reticulocyte count, and percent sickle hemoglobin (HbS%) were collected for 24 months prior to onset of transfusion and for all months during transfusion until the age of 19 yrs. Unless otherwise indicated, all statistical analyses on extracted data were done by paired Student’s t-Test. We extracted data from 103 unique subjects for 108 chronic transfusion programs (as defined above); 5 subjects were chronically transfused twice, separated by at least 4 years without chronic transfusion. 55% were female; average age was 8.6 ± 5.6 (mean ± SD) years and the sickle diagnosis included 94% SS, 3% SC, 2% Sβ°-Thalassemia and 1% SD. The indication for transfusion included pain (n=31), priapism (n=6), ACS (n=5), central nervous system complications (n=37, including stroke, TIA, and abnormal TCD), splenic sequestration (n=25), pulmonary hypertension (n=2), retinopathy (n=1) and osteomyelitis (n=1). The hemoglobin level increased from a baseline of 7.6 ± 2.2 gm/dL to 9.6 ± 0.8 gm/dL during transfusion (p<0.0001, paired t-Test). HbS% was also reduced from a baseline of 84.2 ± 10.8% to 35.8 ± 0.3% during transfusion (p<0.0001). We found that rate of admissions for acute painful episodes, including priapism, dropped from 2.2 ± 2.9 admits/yr during the 24 months pre-transfusion to 1.0 ± 1.9 admits/yr during transfusion (p<0.0001). Similarly, the rate of admission for ACS decreased from 0.3 ± 0.5 admits/yr for 24 months pre-transfusion to 0.1 ± 0.3 admits/yr during transfusion (p=0.0001). Subanalyses were performed on specific indications for transfusion. For children transfused due to frequent acute vaso-occlusive complications (pain, priapism and ACS were arbitrarily included in this group), the average age at initiation of transfusion was 11.9 ± 4.4 yr, and admissions for acute painful episodes dropped from 4.0 ± 3.2 admits/yr during the 24 months pre-transfusion to 2.1 ± 2.6 admits/yr during transfusion (p=0.003). When the indication for transfusion was splenic sequestration (age 2.3±2.7 yr), the admission rate for acute painful episodes did not change (0.8±1.7 vs 0.3±0.5 admits/yr, p= 0.14). For children transfused for CNS complications (age 8.5±4.6 yr), the admission rate for pain improved from 0.9±1.3 to 0.2±0.5 admissions/yr (p=0.007). In agreement with previous studies, our data also showed an increase in the rate of admissions for pain (nontransfused) as subjects aged (r2=0.19, p<0.0001). Thus, the significant improvement in admission rate for pain during transfusion, while the child continues to age, further accentuates the impact of transfusion on the natural history of pain in SCD. In summary, our data suggest that chronic transfusion reduces hospital admissions for pain and acute chest syndrome in children with SCD. Our data also support the notion that chronic transfusion is an effective treatment to prevent not only stroke, but also other painful, life-threatening and life-limiting complications of sickle cell disease. Disclosures No relevant conflicts of interest to declare.

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