Evaluation and Implementation of Complete Blood Count Reference Interval According to the Clinical and Laboratory Standards Institute (CLSI)

Abstract

Complete Blood Picture is an integral part of the diagnosis, treatment and prognosis. It plays a fundamental role in the quality and effectiveness of health care. It is essential to ensure that the right test is carried out on the right specimen and that the correct results are delivered to the appropriate recipient without delay A measured or observed laboratory test result from a person is compared with a reference interval for the purpose of making a medical diagnosis, therapeutic management decision, or other physiological assessment. It is important to develop reference intervals using a systematic process that takes into account the various influences on the measured laboratory test results. Reference intervals were conventionally defined in laboratory medicine as covering the central 95% of a reference distribution composed of analyte values obtained by measurement of samples collected from reference individuals selected randomly from the reference population. Most reference values of haematologic indices currently used in Africa are derived from data collected for populations living in industrialized countries. The few small studies with African populations that have been reported indicate differences in normal values compared with those for populations in industrialized countries. Automated blood cell counters are becoming more sophisticated and the range of reportable parameters available is ever increasing. Both laboratory scientists and clinicians need to keep up to date with new parameters and methods in haematology. Standardization of the tests and establishing biological reference ranges is the first step toward good laboratory practice that ensures reliable results are reported to the clinician. Proficiency testing (PT) is a type of inter-laboratory comparison exercise in which samples are circulated to the participating laboratories; results are then collected and evaluated centrally. It provides a challenge to laboratory’s routine methods and procedures. It also provides feedback to laboratories as to whether they are performing their work in accordance with international criteria for technical competence. In the light of this, current work aimed to monitor standardization of procedures and devices used in the haematology laboratories, prior to establishment of national complete blood picture reference values in Egyptian healthy individuals. Samples for CBC done using LH-750 and GEN-S analyzers, and were examined for the following parameters: total white blood cell count and 5-part automated differential count, red blood cell count, haemoglobin, haematocrit, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, red cell distribution width, platelet count and mean platelets volume. This study was conducted on 50 blood samples collected from healthy adult (18-60 years) at check up clinic Ain Shams Specialized Hospitals. They are divided into group I (using LH-750 analyzer ) and group II (using GEN-S analyzer), then were further subdivided according to gender into group I m (males using LH-750 analyzer), group II m (males using GEN-s analyzers),group I f (female using LH-750 analyzer) and group II f (female using GEN-S analyzer). All participants were first given a health questionnaire to determine eligibility for the study then signed an informed consent and were chosen according to absence to all exclusion criteria. Verification study was done on the performance of both the LH 750 and GEN-S analyzers regarding all parameters were accepted with performance criteria and the study showed accuracy and precision according to the guidelines of American