LoINC and differences in method calibration

I have a question for which I haven’t found an answer in de LOINC manual sofar. In the Netherland most labs use an enzym calibrator (SKML Kalibrator 2000) to calibrate routine enzym assays in serum/plasma. This specially made calibrator is commutable over all assay platforms from different vendors making test results exchangeble. Using this calibrator our upper reference limit for LDH (lactate dehydrogenase; LOINC 2532-0) is < 250 U/l. However, the very same reagent and analyser is used by a lab in Belguim were they don’t use Kalibrator 2000. This lab has calibrated the assay using the molecular extinction coeffficient of the reaction product. Anyway their upper reference limit is < 480 U/l.

If our labs exchange data based on LOINC codes, how are we to know that our assays have a different calibration? Must this be solved by sending reference limits in the HL7 message? That the solution I was thinking about.

Dirk Bakkeren, PhD

Clinical chemist

Máxima Medisch Centrum, Veldhoven :?

Hello Dr. Bakkeren,

I would like to ask for clarification of a few items in your question. When you refer to relaying the “reference limits” in the message, are you alluding to a low to high reference range of normalcy, or the linear cut off level of the assay? Secondly, what version of HL7 are you using?

Thank you for your time,


Dear Pam,

I am talking about the low to high reference range of normalcy. We are using HL7 2.2 and 2.4 depending on the protocol. For some communication other protocols are use like Edifact.

Dirk Bakkeren, pHD

Clinical chemist

Máxima Medisch Centrum

Veldhoven - The Netherlands

Dutch Society for Clinical Chemistry and Laboatory Medicine (NVKC)