Its all a question of quality

Quality is something that is vital in the field of immunodiagnosis and immunochemistry – here we discover how IMMQAS can help maintain your labs  vital quality.

IMMQAS (Immunology Quality Assurance Services) is an umbrella title for the three components of the Immunology, Allergy and Immunochemistry services based at the Northern General Hospital Sheffield.

The department of Immunology in Sheffield is one of 3 Protein Reference Units (PRU) of the Specialised Assay Service (SAS) in the UK - the others are Cardiff and St Georges. We provide both local diagnostic and referred national reference services in immunodiagnostics, allergy and immunochemistry across a large repertoire, together with assistance and advice to referring laboratories.

The UK NEQAS (National External Quality Assessment Service) unit is part of the UK NEQAS Consortium, a charitable enterprise with the role of providing quality assurance programmes, monitoring performance and providing education and assistance to diagnostic laboratories for the UK. It also has a large number of international participants from Europe and further afield.

IMMQAS was formed to enable a "corporate" identity and develop a single portal for accessing the services via www.immqas.org.uk. The website will eventually serve as a single resource for accessing all the educational services of the departments.

The emphasis of the department is on adding value to the result with interpretation and good clinical liaison. There is a daily "duty immunologist" rota ensuring that there is always a point of contact for advice and assistance from a clinical scientist or medical staff via pagers.

The department places a heavy emphasis on education and maintenance of quality in diagnostic laboratories through the annual UK NEQAS participants’ meetings, the CAPA conferences, and via web-based educational initiatives such as the UK NEQAS Interpretive scheme.

Diagnostic Immunology and Protein Reference Unit Laboratories try to select tests on the best performing methodology for clinical utility or lack of susceptibility to common problems. We often have a range of methodologies for trouble-shooting difficult samples referred from outside users. It is very helpful if the sender is specific regarding the reason for referral as this enables us to focus on the question being asked as we have a large diagnostic workload in a current basic test repertoire of over 150 tests. We make available the largest range of specific IgE assays in the UK (over 700 individual allergens/mixes) utilising several manufacturers technologies.

Where appropriate, results are interpreted by a combination of auto-comment rules base and interpretation by the duty immunologist. Clinical advice is available at all times through the medical and clinical scientist staff for both internal and external users of the service. The laboratory is accredited with CPA (UK).

The techniques used in the laboratory are wide and varied; and would span those used in all disciplines of pathology. The laboratory also provides prenatal screening services for Down's Syndrome and a tumour marker service for South Yorkshire.

We have a particular focus on specialised testing in immunology and immunochemistry including ?1 antitrypsin phenotype/genotype, monoclonal immunoglobulin characterisation including IgD, IgE and heavy chain diseases, functional antibodies, investigation of immunodeficiency and complement disorders, cellular immunology, and autoimmunity. Like many diagnostic departments, the use of clinical audit strengthens links and evaluates relevance of test repertoire.

The PRU has an ongoing programme of evaluating new tests/technology.

The purpose of external quality assessment at the UK NEQAS for Immunology, Allergy and Immunochemistry Unit is to:-

• Provide participants with an objective assessment of their performance both within their laboratory and in relation to that of other laboratories.

• Provide information on the relative performance of the available kits and methods.

• Identify factors associated with good and poor performance.

• Monitor and improve the between-laboratory agreement.

The primary aim of UK NEQAS is educational. UK participants with persistent problems are offered advice and assistance and schemes have close links with the professions, ensuring schemes are determined by clinical need.

Participation is on a voluntary, confidential basis and is open to all public and private sector clinical laboratories. Manufacturers of diagnostic instruments and reagents are also encouraged to subscribe to relevant EQA programmes.

Quality assessment programmes available for laboratories

All UK NEQAS designated schemes are members of the UK NEQAS consortium operating on a not-for-profit basis and comply with a code of practice. The Centre for Immunology, Allergy and Immunochemistry provides 19 different EQA Schemes that are fully accredited with CPA (EQA) Ltd and has others in various stages of development. Clinical laboratories from 66 different countries participate in the various EQA programmes also the centre contributes to the production and dissemination of good practice guidelines, for example the National Guidelines for analysis of Cerebrospinal Fluid for Bilirubin in suspected Subarachnoid Haemorrhage.

Specimens are distributed regularly and aim to cover the range likely to be encountered in clinical practice. Participants receive independent, objective and impartial reports on their performance, enabling them to identify weaknesses and take appropriate action. There are Steering Groups which advise on the overall design and operation of the EQA programme and includes the type of samples to be distributed and the frequency of those distributions. They also make recommendations about the derivation of target values and responses, data analysis and data presentation. The format of the individual Scheme reports varies but usually includes a summary page, followed by further pages which give method related statistics for each sample and analyte, and a cumulative performance table.

We have recently launched a new web-based interpretive scheme that replicates the decision-making process for medical and scientific staff, to assist in self-directed learning and which allows individuals to test their interpretation and actions against an example of expert practice (the golden path). The output of this scheme can be used to demonstrate reflective learning and incremental improvement for CPD and re-validation purposes.  The cases will highlight important aspects of diagnostic practice and quality assurance identified by the schemes and their steering groups.

This is an educational tool which has been designed for all grades of scientific and medical staff with no limit to the number of persons being registered to use the system.

The scheme is entirely free of charge but currently restricted to members of staff of the laboratories which currently participate in the EQA programmes available from the Centre.
  
The centre also produces the “SPS” series of working calibrants for the immunochemical determination of specific proteins in serum relevant to clinical practice. They are produced as stabilised liquid preparations in quantities sufficient for NHS hospital laboratories to use them to construct calibration curves in their day-to-day running of their assays and are all compliant with the IVD directive.

Since many commercial companies incorporate calibration materials that are specifically formulated for use their various assay systems, the SPS materials are increasingly being used as ‘third party’ controls.

Analytical values are assigned to each batch by careful calibration in relation to the international reference preparation CRM 470.

The centre is evaluating the need for production of additional materials on an on-going basis, according to clinical needs. 

Authors: Dr William Egner, Consultant Immunologist, Head of Department of Immunology, Director of SAS Protein Reference Unit and the Clinical Immunology and Allergy Unit. Mr Kevin Green is the Lead Laboratory Manager.
Dr Egner is additionally Director of the UK NEQAS Centre for Immunology, Allergy and Immunochemistry. Peter White is the Deputy Director of the UK NEQAS Centre and currently Chairman of the UK NEQAS Executive Committee.