Affiliations: Hemorheology and Haemostasis Unit, Department of Clinical Pathology, La Fe University Hospital, Valencia, Spain | Department of Physiology, University of Valencia, Valencia, Spain | Internal Medicine Service, La Fe University Hospital, Valencia, Spain
Note: [] Corresponding author: Amparo Vayá, MD, PhD, Hemorheology and Haemostasis Unit, Department of Clinical Pathology, La Fe University Hospital, Avda. Campanar 21, 46009 Valencia, Spain. Tel./Fax: +34 96 3862714; E-mail: [email protected]
Abstract: There is little information regarding the behaviour of red blood cell deformability in macrocytosis. We have determined in 114 patients with macrocytosis (MCV > 97 fL) and in 115 age and sex-matched subjects with normocytosis (VCM < 97 fL) erythrocyte deformability by means of ektacytometric techniques (Rheodyn SSD) measuring the erythrocyte elongation index (EEI) at 12, 30 and 60 Pa. Patients with macrocytosis showed statistically higher EEI at all the shear stresses tested when compared with controls (p < 0.001). When patients with macrocytosis were classified according to their main diagnosis as hepatic or renal disease, HIV and miscellaneous, 66.7%, 41.7%, 36.7% and 33.3% of patients, respectively, showed a EEI 60 higher than 61.8% (mean value of the control group + 2 SD). Linear regression analysis demonstrates that MCV, bilirubin, triglycerides and alanine aminotransferase were the main variables influencing EEI 60. An increased surface/volume ratio of the red blood cells may be the main cause related with a higher erythrocyte deformability in a relevant percentage of macrocytosis. Further research is required to confirm our findings by designing case-control pathology-specific studies.
