Quality controls for special parameters in human laboratories

Special Quality Controls

BIOMED’s special quality controls include accuracy control sera for quality control in the analysis of blood concentrations of alcohol, ammonia, cystatin C, bilirubin and various heart markers.

Alcohol-Ammonia Controls

The stable, human serum matrix based liquid control Duotrol^®Alcohol/Ammonia Combi is designed to monitor quantitative analytical conditions for the determination of alcohol and ammonia in human serum and plasma samples in clinical laboratories.

Alcohol

Acute alcohol consumption can be detected by the direct detection of alcohol (ethanol) in the blood (serum or plasma). The measured blood alcohol level can be used to draw relatively reliable conclusions about alcohol levels over a few hours. Alcohol is broken down in the liver by alcohol dehydrogenase (ADH) via acetaldehyde to acetic acid. The rate of degradation varies from individual to individual, with women degrading on average 15 % more slowly than men. Endogenous alcohol does not exceed 0.012 ‰ (per thousand) and therefore need not be taken into account in measurements.

Ammonia

The concentration of ammonia (NH3) in the blood should be determined in cases of changes in consciousness or coma with unclear findings, as well as in infants who vomit constantly or are unusually lethargic. Ammonia is produced in the intestine with the help of bacteria by splitting proteins into amino acids and ammonia. Via the portal vein the ammonia is transported to the liver where it is broken down to urea and glutamine. The urea is then transported to the kidneys and excreted with urine. If this process does not function sufficiently, ammonia accumulates in the blood and can enter the brain, resulting in hepatic encephalopathy (liver-brain disorder). This is a functional disorder of the brain, which can lead to mental and neurological changes with deterioration of cognitive and motor skills up to epileptic seizures, loss of consciousness and coma. Causes of increased ammonia levels can be defects in the urea cycle, severe liver disease, reduced blood flow to the liver, Reye’s syndrome, kidney failure or hereditary hyperammonemia (hereditary ammonia excess).

Bilirubin Controls

Duotrol^®Bilirubin Paediatric is a stable bovine serum-based liquid control for the quantitative determination of bilirubin in the high, abnormal range and is used to monitor assay conditions in clinical laboratory testing of serum and plasma samples. The analyte concentrations are achieved with bilirubin extracts and synthetic derivatives.

Bilirubin

Bilirubin in serum is composed of unconjugated, conjugated and δ bilirubin. Endogenously, 80 – 85 % bilirubin is produced daily. Elevated bilirubin levels are associated with Meulengracht’s disease, hepatitis, fatty liver or liver cirrhosis, bile congestion and hemolysis.

Cystatin C-controls

Duotrol^® Cystatin C is a liquid correctness control serum of human origin with target values in the normal and pathological range.

Cystatin C

Cystatin-C is produced endogenously at a constant rate by almost all nuclear cells in the human body. The serum concentration depends on the glomerular filtration capacity of the kidney. With a reduced GFR the concentration of cystatin C increases. Cystatin C concentration is not influenced by age, sex, muscle mass, nutrition and inflammatory processes (except immune diseases). Cystatin C is elevated in renal insufficiency and autoimmune diseases.