CBR test alcohol use for Psychiatrist

CBR test alcohol use for Psychiatrist

Please note if you order this test your results will go to the specified psychiatrist and your blood will be kept for one year.

Should you want to take the test only for yourself without the results going to the psychiatrist, but only to you then you should order this test: https://www.bloodtesting.nl/cbr-test-2022.html. Then only you will receive the results and the material will be removed after 5 working days.

This involves a blood test for the CBR to check your alcohol use in the past period. This test looks back at your alcohol use for about 3 weeks.

As of 2022, CBR considers these values sufficient for testing. During the blood test, CBR looks for elevated values that indicate excessive alcohol consumption. These are the following blood values:

• %CDT*
• GAMMA-GT (GGT)

*Separate clotting tube is not needed because in this study all tests are done in the same lab.

If you have been drinking alcohol regularly recently, the blood test may show this. This may result in invalidation of your driver's license.

CD-Tect Carbohydrate Deficient Transferrin (CDT)

CDT is a type of protein that is produced when excessive alcohol is consumed over a period of at least a week. The CDT percentage in blood increases as more alcohol is consumed. With abstinence, CDT usually drops to normal within two to three weeks, but after long-term alcohol consumption, this normalization can take much longer.

Measurements for the purpose of driving ability research in the context of alcohol abuse are carried out in specialized laboratories. Since 2019, the results of the allowed methods are all standardized, i.e. traceable to IFCC HPLC reference method and therefore provide, for the same sample, comparable results. The recommended upper limit of 1.7% is used, with a measurement uncertainty of 0.3 percentage point and the cut-off point of 2.0% for forensic use, including driving ability studies. Thus, the cut-off point of 2.0% is the highest value that can still occur in normal population (obviously taking into account measurement uncertainties).

Proteins often have sugar groups, which are necessary for their recognition and function. The characteristics of blood groups, for example, can be traced to different types of sugar groups at the membrane of red blood cells. Also, the iron transport protein transferrin contains two characteristic carbohydrate chains, which together contain an average of four so-called sialic acids.

Under the influence of a degradation product of alcohol (acetaldehyde), a transferrin form arises where one or both carbohydrate chains are absent: we then speak of carbohydrate deficient transferrin or CDT. The CDT is reported as % of total transferrin to cancel out the effect of fluctuations in transferrin levels, for example increasing transferrin in iron deficiency.

The Central Bureau of Driver's Licenses (CBR) also requests targeted laboratory tests in certain cases for persons, who have been arrested with alcohol use in traffic, as part of a psychiatric examination of driving fitness. Previously, tests related to liver function (GGT and ALAT) and mean red blood cell size (MCV) were requested. Currently, measurement of the %CDT is the most important laboratory parameter when excessive alcohol consumption is suspected.

How reliable is the %CDT and at what alcohol consumption is it elevated?

It should be premised that no laboratory test in chronic excessive alcohol consumption will always give an abnormal result, or in technical terms: no method has a sensitivity of 100%. Conversely, with no or minimal use of alcohol a normal result should be obtained, but exceptionally also erroneously elevated values occur, in technical terms: no method is 100% specific.

Scientific research has shown that all in all, the %CDT is the best laboratory parameter for demonstrating chronic excessive alcohol consumption. The upper limit used for CDT in men corresponds to the consumption of an average of about 60g of alcohol per day (roughly 1.5L of beer or 1 bottle of wine per day) for at least one week. Intake of more than 60g of alcohol per day will result in serious long-term organ damage. For women, this limit is about 40g per day.

The Dutch NVKC guideline, which deals with alcohol consumption, uses 2.0% DST as the cut-off point. With results higher than 2.0%, it can be stated with a high degree of certainty that the result does not belong to the normal distribution.

Increased CDT in serum occurs after an average of more than 60g of alcohol is consumed daily for about 2 weeks. When consuming 100 - 400g ethanol/day, the CDT value is normally greater than 4%. After cessation of alcohol consumption, the CDT concentration is still detectable for 2-4 weeks, depending on the amount of alcohol that was ingested. False positive results may occur in individuals with severe liver diseases, such as primary biliary cirrhosis or chronic-active hepatitis.

In addition to the CD-tect %CDT, the following tests are performed by the CBR to monitor recent alcohol consumption: GGT

Gamma-GT

Gamma GT (GGT) is an enzyme made in the liver that aids in the conversion and digestion of substances that enter the body through food and drink. Normally, the concentration of GGT in the blood is very low, but when the liver is under heavy load, the amount can rise considerably. This happens when the liver is fed a lot of substances to process in a short period of time, for example when (extremely) taking drugs or alcohol. GGT will also rise when the bile ducts are blocked, with gallbladder problems, or as a result of liver damage.

What methods can be used for CDT according to the CBR?

As of 2013, the following methods are approved by the NVKC for CBR inspections:

• the N-Latex CDT method from Siemens (upper limit normal 2.2%, cut-off point 2.6%)
• the Analis CE method (upper limit normal 1.5%, cut-off point 1.9%)
• the RECIPE HPLC method (upper limit normal 1,6%, cut-off point 2,0%)
• the HPLC method of BioRad (upper limit normal 1.5%, cut-off point 1.8%)
• the Sebia CE method (upper limit 1,4%, cut-off point 1,7%)
• the HPLC method according to Helander (upper limit normal 1,7%, cut-off point 2,0%)

Blood Values Test uses the Sebia method for this study and on the lab report we use the upper limit of 1.3% just to be sure.

The margin between upper limit normal and cut-off point can be considered a kind of "gray area". This margin includes both the biological distribution within a person and the differences between laboratories. Above the cut-off point it can be said with 95% certainty that a single measured CDT result no longer belongs to the results of a group of normal people. Each method has its own upper limit and cut-off point. Therefore pay attention to which method was used to measure CDT.

As confirmation (or confirmation) studies, only the HPLC method according to Helander is the method of choice.