Summation of Immunology Method Discussions – January – May 2014
From: pdbanning@mmm.com [mailto:pdbanning@mmm.com]
Sent: Wednesday, May 21, 2014 4:05 PM
To: loinc@regenstrief.org
Cc: McDonald, Clem (NIH/NLM/LHC) [E]; dvreeman@regenstrief.org
Subject: LOINC Agenda June 4th - Immunoassay method nomenclature followup
Hello!
The Lab LOINC Submitter's group held monthly meetings January through May to discuss the
possibilities around immunoassay nomenclature. We solicited professional societies and internet
resource groups. Responses came back from pathologists and PhD level professionals, and are
listed along with the opinions of the industry reps and committee members. Clem and Dan were
issued minutes along the way, but for ease of reference, I've created a summation of the discussion
points. I wish we could tell you we found a definitive answer. We found very deep waters in this
arena. I hope the summation interlace well with the discoveries you've made this winter.
See you in a few weeks!
Summation of Immunology Method Discussions – January – May 2014
1. Pathologist and PhD input:
a. Joseph Yao, MD (Mayo) prefers specific method break out to:
 Enzyme immunoassays (EIA, ELISA)
 Chemiluminescensce immunoassay
 Immunodiffusion assay
 Agglutination assay
 Immunofluorescence assay
 Flow cytometry
 Line immunoassay
a. Jon Rosenblatt, MD (Consultant) –listed Radioimmunoassay RIA instead of
Line immunoassay from Dr. Yao above. Otherwise the same: ELISA, MFI,
ELFA, CIA, LA
b. Edwin F. Ullman, PhD (Consultant) – “Much attention has been given to
naming different methodologies but this issue is not discussed directly. Some
critical elements that are often used in naming include homogeneous vs
heterogenous immunoassays, the type of label, and competitive vs various
types of non-competitive immunoassays.” Referred us to The Immunology
Handbook, 4th Edition 2013.
c. James Faix, PhD (Stanford) - “to bring LOINC’s classification of immunoassay
into the 21st century, one first step would be to sub-categorize them as LOINC
has done for nucleic acid “probes”. This first step should NOT be, as Pam
indicates, a differentiation based on the type of signal but something more
basic (again, similar to the way that nucleic acid probes are distinguished),
i.e. competitive vs. non-competitive or homogeneous vs. heterogeneous (or
both). Unfortunately, there is no one place to get the information but The
Immunoassay Handbook (4th Ed. 2013, Elsevier) would be the best reference
to start with.”
2. Reference Laboratory input
a. LabCorp lists methodology in the test compendium, and directors may decide
to have it in the test name, but doesn’t send it in HL7 OBX17
b. Quest Diagnostics lists method in test name; many times just “immunoassay”
c. Mayo Medical Lab tracks specific methodology for research purposes
d. ARUP lists methodology in the test compendium, doesn’t specify further
3. LOINC submitters input
a. Partners’ Healthcare uses methodless whenever possible
b. Premier maps both local catalog and aggregated data; need to be able to
discern when rolling up
c. Canadian preference is to use more methods
d. 3M maps to customers preference, influenced by their use case. In-house
usually not more than EIA, LA, or ID.
4. Observations of the group regarding the use of LOINC names becoming of increasing
use
a. The Long Common Name in LOINC uses the word Immunoassay, even if the
method is EIA, which is more specific. This will be resolved as the output of
the focus study.
b. Character length in certain systems truncate it, not revealing the method
c. There are LIS vendors that take the name from the HL7 message of the
performing lab, and absorb it. If the lab sends the LOINC code first in the
triplet, then the accompanying LOINC description would be the displayed
name
d. Continuity of Care documents may carry the LOINC name forward, dropping
all local names
e. Some EHR vendors are solely recording and displaying LOINC names,
dropping all local names
5. Considerations of change
a. How do the Mayo specifications (ELISA, MFI, ELFA, CIA, LA, RIA) categorize
into competitive vs non-competitive or homogeneous vs heterogeneous or
type of label, as Drs. Ullman and Faix alluded?
b. When would it be appropriate to aggregate if there are different methods?
The Immunology Handbook is rich in many perspectives at 987 pages.
c. What remapping is involved in past mappings, if a non-enzymatic method
becomes available?
d. How would the existing immune complexes by Raji Cell LOINCs harmonize in
if it goes in a new direction? Is this a “competitive vs non-competitive or
homogeneous vs heterogeneous” assay?
e. Will the public make better use of OBX17 (Method) and OBX18 (Equipment
Identifier)?
6. References
a. 3rd edition of Clinical Microbiology procedures handbook, Editor Lynne S.
Garcia, 2007. Table 11.1.2.-1 Generic description of immunologic assays used
in the serologic diagnosis of infectious diseases to the coverage of those
methods in LOINC.
b. 4th edition of The Immunoassay Handbook, Editor David Wild, 2013. ISBN
978-0-08-097037-0
Lab LOINC Submitters Interim Collaboration
Minutes
Friday, May 16, 2014 1 p.m. Eastern
Conference Coordinates:
1-800-937-0042 passcode 5343090#
https://www.callinfo.com/prt?host=level3&an=8009370042&ac=5343090
Attendance:
Discussion
1. Ear/Eye combo culture – Belma has encountered this combination order from a variety of
clients. They may be Ear, Nose and Throat specialties. She’s not certain if it’s for
convenience in the database. It isn’t both sources; it is one or the other. When the lab
collects the swab, the source is edited into the order. Example results back then include the
specimen:
Insert Date
Test
Observation
Specimen_source Body_site
12/30/2013
5:45
C Ear Eye
Few Gram Negative Rods
Eye
Red swab
12/30/2013
5:45
C Ear Eye
2 colonies Gram positive cocci
in clusters
Eye
Red swab
12/30/2013
5:45
C Ear Eye
Few Haemophilus influenzae,
Beta Lactamase Negative
Eye
Red swab
She’s not certain if they use OBX-15 to transmit specimen information, in addition to the
source field within the culture. Belma had placed a request to Regenstrief, and received the
response: ‘Based on the submitted information, the decision is to not model this term in
LOINC. Our experts suggest that two separate system codes (ear or eye) be used as different
bacterial results are expected. Examples are 608-0 Bacteria
identified:Prid:Pt:Ear:Nom:Aerobic culture and 609-8 Bacteria
identified:Prid:Pt:Eye:Nom:Aerobic’
The group asked her if Regenstrief knew she was asking for an order code? It isn’t
necessarily a panel, only one culture/source is returned. Pam asked if the client is using the
SPM segment of HL7, to give more information about the specimen. [For Belma’s benefit,
information on this is available from work led by Riki Merrick at
http://www.phconnect.org/group/laboratorymessagingcommunityofpractice ]
Field
HL7 Name
Consider for coding
Value sets suggested in ELR to PH v2.5.1
SPM-4
Specimen Type
HL70487 / SNOMED CT Specimen
hierarchy
HL70487 / SNOMED CT Specimen hierarchy
SPM-5
Specimen Type
Modifier
SCT qualifier, morphologic abnormality
hierarchy
SCT Qualifier hierarchy
SPM-6
Specimen Additives
HL70371 / SCT substance, product
hierarchy
HL70371
SPM-7
Specimen Collection
Method
HL70488 / SCT procedure hierarchy
HL70488 SCT specimen collection subtree
(procedure hierarchy)
SPM-8
Specimen Source Site
SCT Body site, substance, physical object
hierarchy
SCT body site hierarchy (per HITSP)
SPM-9
Specimen Source Site
Modifier
SCT qualifier hierarchy
SCT qualifier hierarchy
b. A similar situation was recently posted on the LOINC Forum, regarding analyte instead of
specimen. Pam wanted group input before she posted a response. Entry posted states “I
was wondering why orders for microbiology cultures are typically the same as the results
for 'Bacteria identified'. While I understand that if orders were forced to piggyback on a
result codes, this would be the best choice, but why not create separate order-only items for
culture orders? The standard blood culture frequently grows yeast, and while they aren't
the special 'fungal blood culture' orders, it isn't really appropriate to call them 'bacterial
blood cultures'. And the current setup precludes the use of LOINC values to automatically
populate order names.”
PB RESPONSE: I waited to post a response until after the Lab LOINC submitter's
collaboration call today. So we have the benefit of multiple LOINC committee members
contributing here...The codes are named for their intention; the clinician may be asking for
blood cultures; but the lab will always go beyond the code name and always report
whatever is there. It's not taken literally in operational processes. In past versions, the
'bacteria identified' codes were 'microorganisms identified'. Several still reside, including
11475-1. I checked the User's Guide for further explanation, but didn’t find it specifically
addressed.
I do understand from an ordering perspective, LOINC long and short names may be too
granular for a clinician's use. It may infer they are constraining to only one type of microbe.
3M clients to date are using their local code and display name, with the LOINC code and
display adjoining in the HL7 message. I have heard of one instance where an EHR system
implementer was trying to force the LOINC display as the only display. I have also heard of
a CCR document being produced from a local site, that used only LOINC displays. Your
message sounds like your setup is driving in this direction as well. In both instances, the
laboratories involved wanted further discussion on having additional displays available.”
2. Cindy Johns asked the group to review possible coding for Chromosome Microarrays.
Attachments with the minutes include two example reports from LabCorp and one from
Mayo. The main question to the group was – how many of us follow coding selection by
normative values posted in RELMA?
62356-1 Chromosome analysis result in ISCN expression:Find:Pt:Bld/Tiss:Nom:Molgen
ISCN Nomenclature creates the normative answer
62378-5 Chromosome copy number change [Type] in Blood or Tissue by Molecular genetics
Normative answer list: Gain, Loss
62357-9 Chromosome analysis overall interpretation:Imp:Pt:Bld/Tiss:Ord:Molgen
Normative answer list: Normal, Abnormal, Clinical Significance Unknown
64090-4 Chromosome analysis overall interpretation:Imp:Pt:XXX:Ord:Molgen
Normative answer list: Normal, Abnormal, Clinical Significance Unknown
51968-6
Genetic disease analysis overall interpretation:Imp:Pt:Bld/Tiss:Nom:Molgen
Normative answer list: Positive, Negative, Inconclusive, Failure
62365-2
Diagnostic impression:Imp:Pt:XXX:Nar:Molgen
69965-2
Clinical cytogeneticist review:Imp:Pt:XXX:Nar:
69047-9
Geneticist review:Imp:Pt:XXX:Nar:
When Cindy communicated with Regenstrief, 62357-9 was recommended, but LabCorp’s
answer list doesn’t fit the normative answer list. She has been using more of 62365-2. Sue
Korsak recommended Karyotype NAR, but Cindy felt the method was different. Elenore
stated Quest uses 51968-6 without considering the normative list. Pam stated 3M team
encodes to the scale, and also hadn’t been considering the normative answers. The LOINC
User’s Guide was brought up on the screen during the meeting, and states that normative is
fixed answers. The group wondered if the normative answer lists could be changed to
example answer lists? Katy Holck informed the attendance there is a plan to show the
answers on the simple view. The group wondered if the microarrays deserve a new LOINC
code, without a normative answer list?
3. Pam created a Summation of Immunology Method discussion document from the past four
months of meetings and input from this group. It will be forwarded to Regenstrief to aid in
their workup. The group is looking forward to the June LOINC meeting, to see what’s
developed at the organization level.
ATTACHMENTS WITH MINUTES (4):
[Chromosomal Microarray Example reports from Labcorp and Mayo]:
Reveal Pediatric Complex
Reveal Pediatric Normal
Mayo CMAC 61385 example 20140128
Summation of Immunology Method Discussion