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We report here our experience with regular automated red cell exchange transfusion for the management of chronic complications of sickle cell disease in 50 patients in our institution from June 2011 to December 2014. The mean sickle hemoglobin level was 44% and 8.5% pre- and post-transfusion, respectively. Platelets were reduced by a mean 70% during the procedure with a count of less than 50 × 10 /l in 6% of cases. The alloimmunization rate was 0.065/100 units of red cells with no hemolytic reactions. Patients with no iron overload at baseline showed no evidence of iron accumulation with a mean liver iron concentration of 1.6 mg/g dry tissue and 1.9 mg/g dry tissue at baseline and 36 months, respectively. All six patients with pre-existing iron overload and on chelation therapy, showed a gradual reduction of their liver iron concentration and two patients could discontinue chelation during the follow-up period. Seventy percentage of patients who were on the programme for recurrent painful crises showed a sustained reduction in the number of emergency hospital attendances; the mean number of days in hospital for emergency treatment was 103 in the year prior to commencing ARCET and reduced to 62 (40%) after the first 12 months, 51 (50%) after 24 months, and 35 days (66%) after 36 months. J. Clin. Apheresis 31:545-550, 2016. © 2015 Wiley Periodicals, Inc.

In summary, a considerable LA discrepancy rate appears to overwhelmingly represent false-positive results, attributable primarily to anticoagulation. Given that patient anticoagulation status may be unknown to reference laboratories at the time of LA testing, and that clinicians may be unaware of the effect of anticoagulants on APS assays, we propose the following LA evaluation algorithm: [i] include PT testing with all LA evaluations; and [ii] cancel LA testing when both PT and PTT are prolonged; [iii] in the event that only the PT or PTT is prolonged, then heparin neutralization and mixing studies should be done, and subsequent LA testing should only be performed on those plasmas that do not demonstrate correction. While this approach could theoretically miss rare, very weakly reactive LAs (primarily due to lack of sensitivity of our PT reagent), it would eliminate most discrepancies.

No abstract

Serial serum ferritin measurements in adult transfused patients with sickle cell disease have a low sensitivity for identifying patients with iron overload and are of limited value in guiding decision making regarding initiation or monitoring of chelation therapy. The iron status of such high risk patients should be assessed by more definitive ways such as MRI.