Length of sedimentation reaction in blood: a comparison between plasma citrate and K2-EDTA blood samples.

Introduction The erythrocyte sedimentation rate (ESR), now more appropriately referred to as "length of sedimentation reaction in blood (LSRB)", remains the most widely used laboratory test for monitoring the course of infections, inflammatory diseases and some types of cancer. In addition, it is simple and low-cost. The most commonly used procedures for LSRB determination requires plasma-citrate blood samples, following ICSH (International Committee for Standardization in Haematology) recommendations. It is no unlikely that LSRB blood samples are insufficient, especially in children and in haemathological patients. In order to resolve this inconvenient, we compared LSRB measurement in plasma citrate and in K2-EDTA blood samples. Methods We performed our study on 300 whole blood samples from patients of Medicine Laboratory of University Hospital “Tor Vergata” Rome, using an automated procedure (VES-MATIC 60 DIESSE s.p.a.,Grosseto, Italy) Plasma citrate blood samples were analyzed and used as control, whereas K2-EDTA blood samples were transferred in tubes containing sodium-citrate and then analyzed. Statistical correlation was performed using Pearson’s correlation. Results and Discussion Results of linear regression are shown in  Figure. There was a close correlation in LSRB measurements between plasma citrate and in K2-EDTA The regression line had a slope of 0.995 and an intercept of -0.42. The LSRB is a non specific laboratory test widely used in clinical practice. However, this test is used conventionally to detect acute or chronic systemic inflammation in a number of diverse conditions and to monitor the response to therapy. Our results demonstrate that there are not differences between citrate and K2-EDTA plasma therefore LSRB can be eventually measured from the tube collected for hemochrome analysis and so resolve the inconvenient of insufficient samples; besides the use of samples anticoagulated with K2 EDTA can widely reduce the workload in clinical laboratories.