RT Journal Article SR Electronic T1 Short preheating at 41°C leads to a red blood cells count comparable to that in RET channel of Sysmex analysers in samples showing cold agglutination JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 729 OP 734 DO 10.1136/jclinpath-2017-204954 VO 71 IS 8 A1 Antonio La Gioia A1 Maurizio Fumi A1 Fabiana Fiorini A1 Paola Pezzati A1 Fiamma Balboni A1 Maria Bombara A1 Alessandra Marini A1 Ylenia Pancione A1 Leonardo Solarino A1 Elisa Marchese A1 Silvia Sale A1 Vincenzo Rocco A1 Marcello Fiorini YR 2018 UL http://jcp.bmj.com/content/71/8/729.abstract AB Aims The presence of cold agglutinin in blood samples can cause a spontaneous agglutination of red blood cells (RBCs) when low temperature occurs. This phenomenon causes a spurious lowering of RBC count on the automated haematological analysers that are detected by incongruous values (≥370 g/L) of the mean cellular haemoglobi concentration (MCHC). A preheating at 37°C can remove the RBC agglutination generally resulting in a reliable count. It has been reported that the same result can be reached by using the optical reticulocyte (RET) channel of Sysmex analysers where the RBC count is not influenced by the presence of cold agglutinin. This study aims to evaluate these data in a larger population, with regard to environmental conditions on Sysmex analysers. We have also evaluated the influence of different thermal pretreatments on the RBC count.Methods This study was performed on 96 remnants of peripheral blood samples (48 with MCHC in normal range and 48 with MCHC>370 g/L) which have been analysed in different preanalytical conditions on the Sysmex analysers.Results A preheating of samples at 41°C for 1 min leads to a reversibility of the cold agglutination comparable to the one observed in the RET channel and yields better results compared with 37°C for 2 hours.Conclusions None of described procedures assure the complete cold agglutination reversibility in every case. Consequently, since the haematological analysers not yet provide reliable parameters to confirm the complete resolution of agglutination, further verification of RBC count accuracy needs to be performed.