A feasibility study on the effects of Triton X-100 for the in vitro inactivation of Ebola virus on haematological assays.

AIMS: The aim of this study was to check the effect of Triton X-100 on various, commonly used haematology test parameters. METHODS: Anonymised blood samples were treated with 10 µL of 10% Triton X-100 per 1 mL of blood. Treated and untreated samples were tested in parallel for blood film morphology, complete blood counts (CBCs), flow cytometry, blood grouping and antibody screens. Samples were also taken in 3.2% citrate tubes for coagulation test analyses. RESULTS: Statistical differences were noted in all CBC parameters apart from the mean cell volume, eosinophil and basophil counts. Platelet counts were significantly different with an apparent rise after the addition of Triton X-100. Samples were noted to have a high red cell fragmentation index. Immunological platelet counting methods using flow cytometry and fluorescent methods showed no significant differences and gave reliable results. Neither flow cytometry for T-cell subsets nor blood grouping/antibody screens were affected by Triton X-100. However, coagulation samples were severely haemolysed prohibiting analysis. CONCLUSIONS: We have demonstrated that the addition of Triton X-100 to haematology blood samples impacts mainly on platelet counts and coagulation studies due to haemolysis. The platelet count is spuriously raised probably due to the presence of red cell fragments. The latter can be circumvented by the use of immunological platelet counting technology.

Flow cytometry and thromboelastography to assess platelet counts and coagulation in patients with haematological malignancies.

BACKGROUND: Accurate platelet counts (PC) are necessary in order to follow recommendations for prophylactic platelet transfusion. We carried out a study comparing the standard way of counting platelets using a routine analyser and compared it with PC determined by flow cytometry (FC) and haemostatic data obtained with thromboelastography (TEG). MATERIALS AND METHODS: The study was carried out on 24 patients with haematological malignancies, all given one adult dose of platelets. The PC was determined before and after transfusion using an automated blood cell counter and FC. Citrated, "native" whole blood TEG was carried out before and after platelet transfusion to assess global haemostasis. RESULTS: No bleeding was observed in any of the subjects. Thirty-one assessments were performed in the 24 patients. The mean pre-transfusion PC were 9.8 and 13×10(9)/L with the automated counter and FC, respectively with a difference of 3.7 (p=0.0011). Excellent correlation was observed between the two counts (r=0.89; p<0.0001). Mean post-transfusion increments were 23 and 29×10(9)/L for the routine counter and FC, respectively. Using the immunological PC, patients would not have qualified for transfusion in 18.2% of cases since their PC was >20×10(9)/L. TEG showed a shortened reaction time in 69.6% of cases and a normal mean K time of 6.7 min. Only 9% had a low α angle signifying hypocoagulability. The maximum amplitude was reduced in the majority of cases but normal in 25% despite PC<20×10(9)/L. Mean activated partial thromboplastin time, prothrombin time and fibrinogen were normal prior to transfusion. DISCUSSION: Although higher PC as assessed by FC could potentially have an impact on platelet transfusion practices, TEG was sensitive enough to detect PC<10×10(9)/L and some between 10-20×10(9)/L. Whether patients with the latter PC are more prone to bleeding remains to be verified in larger studies.

Evaluation of a method allowing preservation of fresh lymph nodes for flow cytometric immunophenotyping.

BACKGROUND: Flow cytometric immunophenotyping (FCI) of lymph nodes (LN) requires fresh unfixed tissue, with analysis being carried out within few hours post surgery. This study evaluated a novel method for fresh LN preservation, in order to allow histomorphology-based FCI. METHODS: This study was carried out prospectively on 30 LN with suspected involvement by haematolymphoid neoplasms (HLN). FCI was performed on each fresh and post cryopreserved LN cell suspension. Percentage positivities (PP) and mean fluorescent intensities (MFI) were calculated on both preparations for a combination of T and B-lymphoid antigens together with viability. RESULTS: The cryopreservation method applied in this study did not affect significantly PP and had minor impact on MFI of the tested antigens. Overall, there was minimal decrease in PP and MFI on the cryopreserved cells when compared with fresh cells, for most antigens with only a mild increase in apoptotic cells. However, these changes were not diagnostically significant, since both reactive processes and HLN present within analyzed LN could be identified and differentiated. Viability was more than 75% for all cryopreserved LN composed of haematolymphoid cells. CONCLUSION: The method presented in this study confers the possibility of storing fresh LN biopsies for later FCI, thus allowing a morphology-based immunophenotypic approach. This would allow a more sensitive, specific, and cost-effective management of LN specimens, whilst maintaining the important benefits provided by FCI.