No:18 Red Cell Contamination In Leukapheresis Product- A Comparison Between Intermittent & Continuous Flow Apheresis Devices Sajeesh VM*, Mohandoss Murugesan*, Sangeetha K Nayanar# *Division of Transfusion Medicine # Department of Oncopathology Malabar Cancer Centre, Thalassery, Kerala No:18 BACKGROUND Hematopoietic stem cell (HSC) harvest apheresis is a special form of leukapheresis used to collect cells from the peripheral blood that can be used in bone marrow transplant. The blood is separated and mononuclear white blood cells and peripheral blood stem cells are transferred to a collection bag. The other blood components (plasma, red blood cells, platelets) circulate back to the patient during the return cycle. There is no minimum hemoglobin content for patients/donors to undergo stem cell apheresis. Generally most centers maintain Hb threshold of > 8g/dL for stem cell apheresis. In individuals with low Hb levels or body weight <20 kgs, the apheresis circuit require priming with blood to avoid hypotensive complications. Red cell contamination in stem cell product depends on the hematocrit of the patient/donor undergoing the leukapheresis. Since the mononuclear cells align closely to red cell layer during apheresis, higher the RBC contamination, better will be the recovery of mononuclear cells. However with use of Automated Interface Management software in continuous flow apheresis devices, adequate MNC can be harvested with minimal RBC contamination. Increased red cell contamination of the product will result Drop in hemoglobin of the patient/donor after collection Increased risk of hemolysis in the product during its storage at 4C or cryopreservation with increased complications while infusion Need for red cell depletion techniques during Allotransplant procedures. To determine the red cell content in the leukapheresis product with both continuous and intermittent flow apheresis devices To determine the drop in Hb content when using these equipments AIMS 40 leukapheresis procedure for 31 persons (Intermittent 68%; Continuous 32%) 8 persons underwent 2nd procedure (Intermittent 62%, Continuous 38%). No Significant difference in Preprocedure Hb between the two group (Mean Hb:12g.1±1.6/dL). RESULTS METHODS Mean product Hb content Continuous flow: 1.1±0.18g/dL (Range: 0.9 to 1.5g/dL) Intermittent flow: 3.98±1.02g/dL (Range: 2.6 to 6g/dL) Results indicated a significant difference in the red cell contamination of the product between the two equipments (p value <.05). Retrospective study from Jan 2015 to July 2016. Leukapheresis was performed using Intermittent flow (MCS+, Haemonetics) apheresis device till Jan 2016 Both Intermittent & Continuous flow (Spectra Optia, Terumo BCT) apheresis device after Jan 2016. The target blood volume to be processed was set around 2 times the TBV of the patient/donor in both these equipment (adjusted based on WBC count of the patient/donor). The quality control of leukapheresis product was done immediately- Complete Blood Count using LH 780 Cell counter (Beckman Coulter) for calculating MNC, Total Nucleated Cell count and RBC Contamination The products red cell contamination from both the equipments were analyzed and drop in Hb (Pre Hb - Post Hb procedure) in those patients/donor was determined. Interestingly the drop in Hb level was 3 times higher with 1st procedure than 2nd procedure Possible explanation – Plerixafor was given before 2nd collection (CXCR4 antagonist for the mobilization of hematopoietic stem cells) Mean drop in patients Hb post procedure using continuous flow was lower (0.45g/dL vs 0.67g/dL) RBC contamination was 3.6 times higher in stem cell product using intermittent flow apheresis device. Though drop in Hb levels between both the equipments not statistically significant, patients with low Hb or risk of 2nd procedure, stem cell collection using continuous flow device would be better. CONCLUSION