Low Level Leucocyte Enumeration
UKAS Schedule of Accreditation, Accredited to ISO/IEC 17043:2010, Provider 7804
Low level leucocyte enumeration
PURPOSE OF PROGRAMME:
To assess a laboratory's ability to calculate the absolute count (cells/µL) of residual leucocytes in blood transfusion products using flow cytometry
|residual leucocytes||cells/µL (absolute count)|
MATERIAL PROVIDED: Stabilised leucocyte depleted blood and stabilised leucocyte depleted platelets
DISTRIBUTIONS PER YEAR: Minimum 7; Maximum 9
SAMPLES PER DISTRIBUTION: 6
FREQUENCY OF DISTRIBUTION: Approximately 6 weekly as per Trial Schedule (Please note – The Trial Schedule is a guide only and is subject to change)
PROGRAMME OF ANALYSIS:
Results are entered online via the UK NEQAS LI website. Trials are live for 3 weeks. Results can be entered at any time during this period. Under exceptional circumstances late results are accepted at our discretion via email/fax.
Quantitative analysis. Results are scores against the consensus (defined as the robust mean) absolute counts from results submitted by participants.
z scores using robust means and robust SDs with standard limits of +2 and +3 and -2 and -3 as per ISO 13528 A result between 2.0 and -2.0 would be classed as satisfactory. A result between >2.0 and 3.0 or <-2.0 and -3.0 is seen as an 'Action' result, which highlights a potential issue to the laboratory. Two 'Action' results in a period of 3 samples would result in classification as a 'Critical'. A result above 3.0 or below -3.0 is considered to be a 'Critical' result requiring immediate inves
Participant performance is monitored by means of a rolling n+1 sample window where n equals the number of samples per trial issue.
PERSISTENT POOR PERFORMANCE:
Four 'Critical' classifications in a 12 sample period are classed as Persistent Unsatisfactory Performance.
The External Quality Assessment Scheme for Leucocyte Immunophenotyping was established by Professor David Barnett in 1986 at Northern General Hospital, Sheffield. In 1990 the Service became known as the UK National External Quality Assessment Service for Leucocyte Immunophenotyping. UK NEQAS LI is part of the Sheffield Teaching Hospitals NHS Foundation Trust.