Detection of bacterial growth in blood components using oxygen consumption as a surrogate marker in a tertiary oncology setup.

Microbiological contamination of blood and blood products is a well-recognised transfusion risk. This study was performed in the blood bank of our oncology centre, with an objective to detect bacterial contamination in our blood products using oxygen consumption as a surrogate marker [Pall Enhanced Bacterial Detection System (eBDS)]. Results revealed that the percentages of failed units were 1.16% for random donor platelets (RDP), 0.81% for single donor platelets (SDP) and 2.94% for packed red blood cells (PRBCs), of which one RDP and one SDP grew coagulase-negative staphylococcus, while one PRBC culture grew Gram-positive bacilli.

Correlation of CD34+ cell yield in peripheral blood progenitor cell product with the pre-leukapheresis cell counts in peripheral blood.

INTRODUCTION: Accurate timing of the leukapheresis procedures is of paramount importance to get the best possible CD34+ cell yield in the minimum number of leukapheresis procedures. AIM: To find if pre-harvest CD34+ cell concentration in peripheral blood correlates with CD34+ cells in the product. MATERIAL AND METHODS: Sixty Leukapheresis procedures were performed for 25 patients (8 autologous and 17 allogeneic transplants) with hematological malignancies. Statistical analysis was performed to correlate the pre-harvest CD34+ cell count and the CD34+ cell yield. Volume processed during PBPC harvests was three times the blood volume. RESULTS: The best correlation was found between the leukapheresis product CD34+ cell count and the pre-harvest PB-CD34+ cell count (PCC=0.674) when compared with the other pre-harvest PB cell counts viz., WBC (PCC=0.229) and MNC (PCC=0.324). This correlation was better in the allogeneic harvest (PCC = 0.645) than the autologous harvest procedures (PCC = 0.348). Correlation analysis based on paired samples from the 60 leukapheresis procedures showed that when the pre-leukapheresis PB-CD34+ cell count was >20x10(3)/ul a yield of >1x10(6) CD34+ cells/Kg could be obtained in 95% of the cases and >2x10(6) CD34+ cells /Kg could be harvested in 68% of cases whereas when the pre-leukapheresis PB-CD34+ cell count was <5x10(3)/microl the yield was <1x10(6) CD34+ cells/Kg in 81% of the procedures. CONCLUSION: The yield of CD34+ cells in PBPC harvests depends on the pre-harvest CD34+ cell concentration and therefore it is more useful than the pre-harvest WBC or MNC counts for predicting the appropriate timing of the harvests and also to achieve the best possible yield of CD34+ cells.

Plasma exchange for thrombotic thrombocytopenic purpura following hematopoietic stem cell transplantation.

A 17 years old female diagnosed with acute myeloid leukemia (AML)-M2 received an allogeneic haematopoietic stem cell transplant (HSCT) and was given graft versus host disease (GVHD) prophylaxis with methotrexate, cyclosporin-A (CsA) and methyl prednisolone. On day +42 post-transplant, she was diagnosed to have thrombotic thrombocytopenic purpura (TTP). Therapeutic plasma exchange (TPE) (40 ml/kg body mass) using fresh frozen plasma was performed on 8 consecutive days. The renal function, LDH levels, platelet count and peripheral smear findings improved but the neurological symptoms persisted even after TPE. Few reports are available in literature on the effectiveness of therapeutic plasma exchange (TPE) in post-bone marrow transplant (BMT) TTP. The good hematologic response achieved in this patient suggests that TPE could be life-saving and should be tried in every patient with post-BMT TTP.

Exchange transfusions via peripheral vessels.

During a 15 month period, partial exchange transfusions (ET) were done in 40 neonates with polycythemia, and double volume ET attempted in 7 neonates with hyperbilirubinemia via peripheral vessels. The procedure was effective and not associated with any complications for partial ET. During double volume ET minor complications were noted in 2 cases, both of whom recovered and subsequently successfully underwent supraumbilical ET. Of the 5 cases who had uneventful double volume exchanges, there was a significant drop in indirect serum bilirubin following the procedure. The mean pre-ET serum indirect bilirubin in these 5 cases was 334 mumol/L and mean post-ET level was 179 mumol/L with a mean drop of 155 mumol/L (46% drop). Technical difficulties in catheterization may be overcome with greater expertise and use of heparin to flush arterial catheters.