Clinical Biochemistry and Immunology
The Clinical Biochemistry Department analyses body fluids to provide biochemical information for disease diagnosis, treatment and management The Immunology Department at CWPS provides a comprehensive diagnostic service for the investigation and monitoring of immune system disorders.
The Clinical Biochemistry Department analyses body fluids to provide biochemical information for disease diagnosis, treatment and management. We use automated analysers to measure a wide range of substances in blood, urine and other fluids, including electrolytes, glucose, enzymes, lipids, hormones, tumour markers and drug levels. The data produced is essential for assessing organ function like the kidneys and liver, and monitoring the patients’ health status. The results provide crucial information that doctors use to diagnose and monitor disease states such as thyroid disease and cystic fibrosis.
The Department supports the national
Fetal Anomaly Screening Programme, which offers screening to assess the chance of the baby being born with Down's syndrome, Edward's syndrome or Patau's syndrome and a number of structural conditions of the developing baby.
The Immunology Department at CWPS provides a comprehensive diagnostic service for the investigation and monitoring of immune system disorders. Our expert team supports clinicians across the region by delivering high quality testing for autoimmune diseases, allergies, and related conditions. Using advanced laboratory techniques and a patient centred approach, we ensure timely and accurate results to guide effective clinical decision making.
Click here to view Clinical Biochemistry and Immunology test database
Click here to view common interferences in Biochemistry tests
Haemolysis, icteric and lipemic indices are measured on all Biochemistry samples and tests results are not reported when the indices are above the accepted reportable cut off where there is likely to be significant interference for that test
EDTA contamination (e.g. from FBC tube): Potassium will be increased, Calcium, magnesium and ALP decreased.
Prolonged delay in centrifugation of sample: Potassium, phosphate, LDH will be increased, and bicarbonate decreased.
Inappropriate sampling site, e.g. sample taken from a drip arm: Increase in drip analyte (e.g. sodium or glucose). Dilutional effect likely to be seen on other analytes.
Potential for Biotin interference in Immunoassays
The use of over-the-counter (OTC) high dose biotin (Vitamin B7) supplements has gained popularity in recent times. Many patients take biotin supplements (generally 5-10 mg tablets) marketed as beauty products to improve the health of hair, skin and nails. High-dose biotin (100 mg) is sometimes prescribed to treat metabolic diseases and there are also ongoing trials of mega-dose (up to 300mg/d) Biotin in Multiple Sclerosis. The Biotin – Streptavidin couple is part of the assay design for many biomarker immunoassays. If patients are taking large doses of this Biotin / Vitamin B7, there is known potential for significant interference in immunoassays for a number of commonly requested tests in Biochemistry.
Interference may be positive or negative depending on assay design: sandwich-type immunoassays are generally negatively affected, and competitive designs are usually positively affected.
If you have a test result that does not fit with the clinical picture, it is worthwhile excluding biotin ingestion as a potential cause of test interference, by asking the patient / parent / carer about any OTC supplements or checking for a biotin prescription.
Clinicians caring for patients being investigated for chest pain / acute coronary syndrome should take particular care when interpreting Troponin I results where biotin can cause a negative interference and potentially falsely reassuring results. In such cases, the clinician should ask about biotin supplements for all patients for which a Troponin I is requested.
Please contact the Duty Biochemist if you wish to discuss any results where interference is suspected.