59261-8

Hemoglobin A1c/Hemoglobin.total standardized per IFCC-RMP for CDT in Blood

Active

Term Description

This term is not proposed for use in the United States, who will continue to use the NGSP protocol and report the Hgb A1c as %.

Hemoglobin A1c measured using IFCC reference materials. The International Federation of Clinical Chemistry Working Group (IFCC-WG) on HbA1c has recommended a new approach to HbA1c analysis that uses mass spectroscopy and capillary electrophoresis as the reference methods, and set of reference laboratories that use prepared mixtures of purified Hemoglobin A1c and HbA0 as calibrators. (http://www.ngsp.org/prog/IFCCstd.pdf). The IFCC method is reported as millimoles/Mole - which resolves to units that are ten times the value of a pure fraction. The value number produced by the IFCC method differs by less than a factor of ten from the NGSP approach which has been the standard in clinical care since DCCT/UKPDS diabetes studies. A value of 6% under the NGSP method would be 42.8 millimole/mole when tested by the IFFCC approach (per the conversion formula in the above reference). Many countries will report the IFCC value along with the NGSP values and the estimated average glucose - at least for a time. In the US the policies are not as clear and there is at least a chance of no change in the current reporting style will occur. (Source- many- written by CJM 2010 04 27).
Source: Regenstrief Help

Part Description

LP16413-4   Hemoglobin A1c
Currently (2010), four standardization protocols exist for measuring Hgb A1c:

1. IFCC - designated as a Reference Method or RM (http://www.ifcchba1c.net/)
2. NGSP - the long standing protocol used in the US and most other countries since the DCCT study (http://www.ngsp.org/factors.asp)
3.JDS/JSCC - a protocol used in Japan, Spain and possibly other countries
4. Swedish - used in Sweden at least

Protocols 2-4 are known as Designated Comparison Methods (DCM) and have been connected to the Reference Method and each other through various regression equations.

Because of the high degrees of standardization within protocol it should no longer be necessary to specify a LOINC code with a method such as "HPLC", "electrophoresis" or anything else. Analytical instruments will be designed so that an Hgb A1c result can be traced back to a specific standardization protocol, so the important distinction will be the standardization protocol as described above and which will be carried in the method field.

A meeting of instrument manufacturers (presumably including Japanese) in Milan, Italy, December 12, 2007, agreed (among other items) that:

-All manufacturers should implement worldwide the traceability to the IFCC reference system for Hgb -A1c.
-All new instruments sold after January 1st, 2011 will report (as a result of an Hgb A1c test) both SI (mmol/mol - no decimals) and NGSP derived units (percentage - one decimal), in agreement with the Consensus Statement.
-Note they only committed to supporting protocol (1) and (2)

Different countries are adopting the international harmonization recommendations in different ways. We have information from the NGSP that the US will continue to report only Hgb A1c/NGSP, with the unit percent - i.e., no change. In Great Britain, labs have already started to report all results both as Hgb A1c (NGSP) in % and Hgb A1c (IFCC) in mmol/mol. In Canada, they are awaiting a recommendation from an expert panel. Any of these measures could be reported in the same units, but the convention for the reporting Hgb A1c under the new IFCC protocol will be to use units of mmol/mol to avoid confusion between the DCCT/NGSP and the IFFCC protocol.

LOINC has defined 59261-8 (Hemoglobin A1c/Hemoglobin.total in Blood) by IFCC protocol.

These protocols produce different results when expressed in the same units. For example, the equivalent of Hgb A1c (NGSP) of 6.5% is Hgb A1c (IFCC) is 4.8%.

The NGSP web site (http://www.ngsp.org/factors.asp) suggests the use of alternate measures, such as glycated albumen, for patients with severe iron deficiency, dialysis patients, and those with SS SC CC because of over or under reading that can occur with these interferences. It also describes the effect of abnormal hemoglobins on results of HbA1c by instrument.

Studies have demonstrated racial and ethnic differences in the relationship between glucose levels and hemoglobin A1C [22238408], and it has been suggested that some descendants of sub-Saharan Africa may have higher levels of measured hemoglobin A1C compared to glucose levels due to hemoglobin variants PMID: 31675503. Source: Regenstrief Help

LOINC Names Get Info

Fully-Specified Name

Hemoglobin A1c/Hemoglobin.total^^standardized per IFCC-RMP for CDT:SFr:Pt:Bld:Qn:

Long Common Name

Hemoglobin A1c/Hemoglobin.total standardized per IFCC-RMP for CDT in Blood

Short Name

HbA1c per IFCC-RMP for CDT SFr Bld

Display Name

HbA1c standardized per IFCC-RMP for CDT (Bld) [Molar fraction]

Consumer Name Alpha Get Info

HbA1c/Total Hgb Standardized per IFCC-RMP for CDT, Blood

Part Model Get Info

• Component

  Hemoglobin A1c/Hemoglobin.total^^standardized per IFCC-RMP for CDT
  LP448339-4

  • Analyte

    Hemoglobin A1c/Hemoglobin.total
    LP286151-8

    • Component Numerator

      Hemoglobin A1c
      LP16413-4

      • Component Numerator Core

        Hemoglobin A1c
        LP16413-4

      • Component Numerator Core Suffix

        NULL
         

    • Component Denominator

      Hemoglobin.total
      LP32069-4

      • Component Denominator Core

        Hemoglobin.total
        LP32069-4

      • Component Denominator Core Suffix

        NULL
         

  • Challenge

    NULL
     

  • Adjustment

    standardized per IFCC-RMP for CDT
    LP310257-3

  • Count

    NULL
     

• Property

  SFr
  LP6866-0

• Time

  Pt
  LP6960-1

  • Time Core

    Pt
    LP6960-1

  • Time Modifier

    NULL
     

• System

  Bld
  LP7057-5

  • System Core

    Bld
    LP7057-5

  • Super System

    NULL
     

• Scale

  Qn
  LP7753-9

• Method

  NULL
   

Basic Attributes

Class

CHEM

Type

Laboratory

First Released

Version 2.32

Last Updated

Version 2.83 (MIN)

Change Reason

Release 2.70: CLASS: Changed Class from HEM/BC to CHEM as A1C tests are more correctly classified in CHEM.;

Order vs. Observation

Both

Common Test Rank Get Info

2804

Member of these Panels

Language Variants Get Info

Related Names

• Blood
• Chemistry
• Endocrine
• Endocrinology
• GHb
• Glycated hemoglobin
• Glycohaemogolobin
• Glycohemogolobin
• Glycosylated hemoglobin
• HA1c
• Haemoglobin
• Hb
• HbA1c
• HbA1c /HbTotal per IFCC-RMP for CDT
• Hgb
• Hgb A1c
• Percent
• Point in time
• QNT
• Quan
• Quant
• Quantitative
• Random
• Substance fraction
• Tot
• Totl
• WB
• Whole blood

Example Units

LOINC Terminology Service (API) using HL7^® FHIR^® Get Info

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CodeSystem lookup

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LOINC Copyright

Copyright © Regenstrief Institute, Inc. All Rights Reserved. To the extent included herein, the LOINC table and LOINC codes are copyright © Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. See https://loinc.org/license for the full LOINC copyright and license.