LP95062-3 LC/MS/MS includes both LC/MS and LC/MS/MS?

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  • #455945
    HIU LAAM LAM
    Participant

    Dear members,

    May I know if “LP95062-3 LC/MS/MS” actually represents both “LC/MS” and “LC/MS/MS” please?

    LC/MS = Liquid Chromatography mass spectrometry

    LC/MS/MS = Liquid Chromatography with tandem mass spectrometry

     

    Thank you.

     

    Regards,

    Katherine

    #455947
    Pam Banning
    Moderator

    Hello Katherine,

    The LC/MS/MS LOINC Part has a document attached to it as the source. The link is here if you didn’t see it: https://www.mayocliniclabs.com/media/articles/documents/mass-spec.pdf  .

    The LC/MS/MS LOINC Part represents the method has a second mass spectrophotometry measurement after the initial liquid chromatography-mass spectrophotometry, making it more of a confirmation method.

    The LOINC User’s Guide has a short discussion on these different methods under Section 3.8 Toxicology – Drug abuse screening and confirmation.

    I would suggest if there are different LOINC Parts in existence, that one does not overlap or substitute for another.

    LP6292-9 Gas Chromatography

    LP6319-0 High Pressure Liquid Chromatography

    LP95262-3 Liquid Chromatography/Mass Spectrophotometry/Mass Spectrophotometry

    Does your laboratory have a different technology? You may want to consider submitting for a new LOINC term.

    Best regards,

    Pam Banning,

    Lab LOINC committee chair

    #455955
    HIU LAAM LAM
    Participant

    Dear Pam,

    Thank you for your prompt reply.

    Referring to your reply, there is no single LOINC parts for liquid chromatography-mass spectrophotometry (LC/MS). Thank you.

    Regards,

    Katherine

    #455956
    Pam Banning
    Moderator

    Hello Katherine,

    The LOINC parts are created from the fully defined LOINC. If you make a submission for a new term that incorporates a single LC/MS, it is possible the LOINC Part will be created. That being the ideal theory, keep in mind if you are talking about toxicology/drug analysis the method of screen and confirm are used to indicate the first method from the second method of detection. Screen and Confirm in toxicology covers all bases.

    Could you share here with an example analyte/assay to be mapped?

    Thank you,

    #455961
    HIU LAAM LAM
    Participant

    Dear Pam,

    Thank you for your reply. I am trying to look for concept for mapping serum cortisol done by MS. I am struggling whether the methodology should be simply using MS, LC/MS or LC/MS/MS. Since I found that there are no MS or LC/MS LOINC part, thus I am thinking whether LC/MS/MS also represents LC/MS in LOINC. Thanks for your clarification and now I understand that LC/MS/MS does not represents LC/MS and if LC/MS is needed, we may further make submission.

    Thank you.

    Regards,
    Katherine

    • This reply was modified 4 months, 2 weeks ago by HIU LAAM LAM.
    • This reply was modified 4 months, 2 weeks ago by HIU LAAM LAM.
    #455964
    Pam Banning
    Moderator

    Hello Katherine!

    Thank you for the example. I would like to refer you to pg 150 in the LOINC User’s Guide “Before you submit”. “Please note that we tend to avoid the use of methods for chemistry tests. We will not routinely accept requests for method-specific chemistry tests. Only in very special circumstances will we distinguish among analytic methods in chemistry. We do distinguish microbiology, serology and coagulation tests by method type. Even here, however, we do not distinguish every variation in method. Look in the body of this User’s guide for information about the kinds of distinctions we make.”

    I recall Dr. McDonald explaining in person that the chemistry arena of laboratory is well calibrated with little variance among sensitivity and specificity. The method attribute can be used to infer a less specific/sensitive method, such as latex agglutination as compared to Western blot.

    You would be perfectly correct in using one of the methodless concepts for cortisol, varying by the units of measure reported.

    For metric (grams/volume), 2143-6 Cortisol:MCnc:Pt:Ser/Plas:Qn:

    For molar (moles/volume), 14675-3 Cortisol:SCnc:Pt:Ser/Plas:Qn:

     

    #455965
    HIU LAAM LAM
    Participant

    Dear Pam,

    Thank you very much for your detailed information. We will pass the message to our team for further discussion on the mapping.

    Regards,
    Katherine

    #455966
    Dirk Bakkeren
    Participant

    Hi Pam,

    I have a question that is closely related to the question of Katherine. We use LOINC code 91671-8  “<span id=”xf-951″ class=”xforms-control xforms-output”><span id=”xf-951≡≡c” class=”xforms-output-output”>Transferrin.carbohydrate deficient.disialo/Transferrin.total standardized per IFCC-RMP for CDT in Serum or Plasma”. However, there are several</span></span> routine methods to perform this test. When people have an increased CDT often a confirmation test is requested, as the consequence of an increased CDT can be the withdrawal of their drivers license.
    However, as there is only one LOINC code the confirmation test (HPLC reference method) can not be differentiated from a routine CDT test. How can such an issue be beste resolved?

    #455967
    Pam Banning
    Moderator

    Hello Dirk,

    Curious to know the use case and displays of the confirmation CDT test and presuming it’s a different order code from the initial assays? These three variables augment the LOINC’s stance: a display like “CDT Confirmation” along with it being ordered only on initially high results.  91671-8 is conveying the assay, specimen, scale, etc. The business/operational process of only reporting elevated CDT confirmation assay on from the clinician to the governing authorities portrays the severity of the situation.

    As you’re aware, toxicology is the area where Regenstrief has designed Screen and Confirmation methods for differentiation. Only the laboratory information systems having two assays built can use those LOINCs for each drug. Otherwise the methodless term is used where the confirmation overlays the initial screen result in the same field. In those instances, it’s likely a confirmation footnote is added.

    Your team is welcome to submit for a confirmation CDT LOINC if this is an insufficient discussion.

    Have a great weekend,

    Pam

    #455968
    Pam Banning
    Moderator

    Hello Dirk,

    Curious to know the use case and displays of the confirmation CDT test and presuming it’s a different order code from the initial assays? These three variables augment the LOINC’s stance: a display like “CDT Confirmation” along with it being ordered only on initially high results.  91671-8 is conveying the assay, specimen, scale, etc. The business/operational process of only reporting elevated CDT confirmation assay on from the clinician to the governing authorities portrays the severity of the situation.

    As you’re aware, toxicology is the area where Regenstrief has designed Screen and Confirmation methods for differentiation. Only the laboratory information systems having two assays built can use those LOINCs for each drug. Otherwise the methodless term is used where the confirmation overlays the initial screen result in the same field. In those instances, it’s likely a confirmation footnote is added.

    Your team is welcome to submit for a confirmation CDT LOINC if this is an insufficient discussion.

    Have a great weekend,

    Pam

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