Effective and efficient laboratory services are characterized by three things, namely precision, accuracy, and accuracy time, as assessed by turnaround time (TAT). It was reported that the preanalytic phase is the phase that contributes about 75% of the total TAT. One of the preanalytic processes that must be considered is the centrifugation process. Centrifugation is the process of separating solid particles and their solvents. This centrifugation is often used in laboratories to separate blood cells from their plasma to produce Platelet Poor Plasma (PPP). PPP is plasma that has a platelet content of less than 10,000 / µL, which can then be used for coagulation physiological examination.
Centrifugation parameters to remove platelets depend on the speed and radius of the centrifuge arm (both determine the value of “g”), and the time of centrifugation. Therefore, each centrifuge produces a different g value and varies the centrifugation time to get the desired PPP. The Clinical and Laboratory Standard Institute (CLSI) recommends that tubes with sodium citrate anticoagulant should be centrifuged at a rate of 1500 g for no less than 15 minutes to obtain PPP.
Meanwhile, the research of Kristoffersen AH., 2019, reported that the number of platelets after single centrifugation of 1500g turned out to produce remaining platelets> 10,000 µL, namely <22,000 / µL. According to Magnette A et al. repeated centrifugation was required to ensure that the platelet residue was less than 10,000 / µL. Plasma residual platelets have been found to influence phospholipid-dependent coagulation tests such as Lupus Anticoagulant (LA) and Activated Partial Thromboplastin Time (APTT). The centrifugation process should be prepared for all coagulation parameters, and the measurements will not be made immediately after centrifugation.
Currently, the PPP preparation process at Dr. Soetomo was centrifuged at 3000 g for 15 minutes. Still, it has not been studied whether centrifugation at this rate resulted in platelet residue of less than 10,000 / µL. The centrifugation process for obtaining PPP requires a strategy to speed up the process without compromising the quality of the coagulation physiological examination. Recent research conducted by Sicard in 2014 showed that the amount of platelet residue in PPP produced at a rate of 3260 g in just 10 minutes was
Samples were obtained from healthy adult patients who had a medical check-up and had given their consent to participate in the study. Blood samples were collected using three tubes with 2.7 ml citrate anticoagulant. The sample centrifuged using Sorvall ST 8R (Thermo Scientific small benchtop centrifuges) at 24 ° C. The three samples were centrifuged at three different speeds and times, namely at a centrifugation speed of 1500 g for 15 minutes 2 times (Technique 1), 3000 g for 15 minutes (Technique 2), and 3260 g for 10 minutes (Technique 3).
The plasma is carefully transferred to an inactive plastic centrifugation tube using an automatic pipette and then centrifuged again for about 15 minutes. Whereas in Technique 2 and 3, only one centrifugation is carried out. When pipetting, 1 cm of plasma must remain above the buffy coat layer, to avoid picking up remaining platelets in the area around the buffy coat. Plasma from each sample was then assessed for the platelet count using a hematology analyzer Sysmex XN 1000.
From 31 samples studied from all centrifugation techniques, all yielded a platelet count below 10,000 / µL. In the 1500g centrifugation technique for 15 minutes twice, the median value of the platelet count was 1 × 103/ µL (0-3). For the 3000g centrifugation technique for 15 minutes, the median number of platelets was 1 × 103/ µL (0-5). In the 3260g centrifugation technique for 10 minutes, the median number of platelets was 2 × 103/ µL (0-5). When comparing the platelet counts between groups, the centrifugation technique was significantly different (p <0.05).
In conclusion, the three centrifugation techniques are capable of producing PPP. In the 1500g centrifugation technique for 15 minutes twice produce the lowest platelet count.
Author: Dr. Yetti Hernaningsih, dr, Sp.PK (K)
Link:
http://medicopublication.com/index.php/ijfmt/article/view/10559/9897
Pande Putu Rangga Raditya1, Yetti Hernaningsih2
1, Student, 2Lecturer, Department of Clinical Pathology, Faculty of Medicine-Universitas Airlangga, Dr. Soetomo Hospital General Academic Hospital, Surabaya, Indonesia
