Hi,
What are L-indices standardised against? Do the method sheet/inset specify what has been used as the reference material? I suspect that you found a correlation by spiking with Intralipid as the assay may been aligned to an Intralipid reference solution. Could also explain the poor correlations seen against triglyceride noted by others.
Danny
> On 2 Sep 2015, at 15:53, Paul Hamilton <[log in to unmask]> wrote:
>
> Dear All,
>
> I found a strong correlation between lipaemic index and triglyceride concentration measured on a Roche COBAS 8000 analyser, in a very small experiment using samples spiked with 20% intralipid. See attached chart.
>
> Best wishes,
>
> Paul
>
> Specialty Registrar in Chemical Pathology (Metabolic Medicine)
> Belfast Health and Social Care Trust
> Department of Clinical Biochemistry, Kelvin Building, Royal Victoria Hospital
> Grosvenor Road, Belfast, Northern Ireland, BT12 6BA
>
>
>
>
> --------------------------------------------
> On Wed, 2/9/15, Waller, Paul <[log in to unmask]> wrote:
>
> Subject: Re: Lipaemia index
> To: [log in to unmask]
> Date: Wednesday, 2 September, 2015, 15:34
>
> To add my own unpublished
> observations;
>
> Intralipid
> behaves very differently to endogenous chylomicrons, and can
> cause apparent interference in kinetic assays. My unproven
> hypothesis was that this was due to detergents/surfactants
> in reagents breaking down the lipid vesicles and thus
> causing a decrease in absorbance due to turbidity.
>
> I did not see this phenomenon
> to the same extent in lipaemic patients sera.
>
>
> Paul Waller
> MSc CSci FIBMS FHEA
> Associate Professor in
> Biomedical Science
> Associate Head
> Biomolecular Sciences
> School of Life
> Sciences, Pharmacy and Chemistry
> T 020 8417
> 7783 (Direct Dial) / 67783 (Internal)
> E [log in to unmask]
> / Web page Mr Paul Waller
>
> Room PR MB 1019, Penrhyn Road, Kingston upon
> Thames, KT1 2EE
>
> Office
> hours by appointment
>
> -----Original Message-----
> From: Clinical biochemistry discussion list
> [mailto:[log in to unmask]]
> On Behalf Of [log in to unmask]
> Sent: 02 September 2015 15:24
> To: [log in to unmask]
> Subject: Re: Lipaemia index
>
> Well put, Graham. I was going to reply
> similarly, but I think you describe very well the
> variability in chylomicron particle size and their
> triglyceride content. As I mentioned previously in this
> thread, several publications and my own unpublished
> observations show that there is very little correlation
> between L (or T)-index and triglyceride concentration in
> lipemic specimens.
>
> Note
> that Soha Zouwail mentioned to me off list that she found
> good correlation between the triglyceride concentration in
> Intralipid and L-index. I have used Intralipid to check for
> lipemia (turbidity) interference, but did not look at the
> correlation with the L-index. In fact, I think the last time
> I did such interference studies was before the specimen
> indices era. I think this makes sense though because the
> lipid vesicles of Intralipid are likely to be much more
> uniform than chylomicrons.
>
> -Jim
>
> -----Original Message-----
> From: Clinical biochemistry discussion list
> [mailto:[log in to unmask]]
> On Behalf Of Graham Jones
> Sent: Wednesday,
> September 02, 2015 8:27 AM
> To: [log in to unmask]
> Subject: Re: Lipaemia index
>
> Derreck,
>
> I
> expect not. Rather than having a lot of nice fresh
> chylomicrons, all the same size and same triglycerides (TG)
> content (and perhaps the same light scattering), I would
> expect in any sample we may have a range of difference sizes
> and TG content (and light scattering) as they lose TG to
> tissues on their way to the liver. Thus the relationship
> between TG and light scattering is not very close.
>
> Just my thoughts,
>
> Graham
> ________________________________________
> From: Clinical biochemistry discussion list
> <[log in to unmask]>
> on behalf of Mccullough Derreck (UHMB) <[log in to unmask]>
> Sent: Wednesday, 2 September 2015 6:45 PM
> To: [log in to unmask]
> Subject: Re: Lipaemia index
>
> Hi Jim,
> As chylomicrons are
> 90% triglyceride would you not expect a good correlation
> between triglycerides and turbidity if turbidity is caused
> by chylomicrons?
>
> Bw,
> Derreck
>
> -----Original Message-----
> From: Clinical biochemistry discussion list
> [mailto:[log in to unmask]]
> On Behalf Of [log in to unmask]
> Sent: 26 August 2015 18:14
> To:
> [log in to unmask]
> Subject: Re: Lipaemia index
>
> Replying to myself here! I agree with Alan that
> Sonia's triglyceride vs L- (or T-index) is much higher
> than expected. I've had a chance to dig out one of my
> correlations: Triglyceride, mg/dL = 0.88 L-index + 185, R^2
> = 0.017. (Sorry for U.S. units, but the key here is the very
> low R^2.) My bad that I didn't indicate the
> instrument/method on the graph, but it was a Roche
> instrument, probably an Integra. Also, earlier I implied
> that VLDL, being triglyceride rich, would increase the
> L/T-index. VLDL rarely does, but most often it is
> chylomicrons that cause the turbidity.
>
> Sonia, you mention that your L-index results
> are binned, that is, 1+, 2+, etc. yet your graph has numbers
> for the L-index. Does your Architect give you both the
> numerical L-index and the binned result?
>
> -Jim
>
> ------ACB
> discussion List Information-------- This is an open
> discussion list for the academic and clinical community
> working in clinical biochemistry.
> Please
> note, archived messages are public and can be viewed via the
> internet. Views expressed are those of the individual and
> they are responsible for all message content.
> ACB Web Site
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.acb.org.uk&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=ASzVuUmIgFDfaCCPNg6C4bgK3LpvhQhHVI9iLJIaxRU&e=
> Green Laboratories Work
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.laboratorymedicine.nhs.uk&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=3--mLJT9NarSD613B7aQMMDh0Xri-UDmXRPZ6T9r1rU&e=
> List Archives
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.jiscmail.ac.uk_lists_ACB-2DCLIN-2DCHEM-2DGEN.html&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=cMxp_NanXU8H1bMHft0ynXNqWBO9iOXZ39XRyBZ8egc&e=
> List Instructions (How to leave etc.)
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.jiscmail.ac.uk_&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=rZZbQTBaSsZV_YDduI9RBB11sTw04YoR2N1dzUqzMag&e=
>
>
> ------ACB discussion
> List Information-------- This is an open discussion list for
> the academic and clinical community working in clinical
> biochemistry.
> Please note, archived messages
> are public and can be viewed via the internet. Views
> expressed are those of the individual and they are
> responsible for all message content.
> ACB Web
> Site
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.acb.org.uk&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=ASzVuUmIgFDfaCCPNg6C4bgK3LpvhQhHVI9iLJIaxRU&e=
> Green Laboratories Work
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.laboratorymedicine.nhs.uk&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=3--mLJT9NarSD613B7aQMMDh0Xri-UDmXRPZ6T9r1rU&e=
> List Archives
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.jiscmail.ac.uk_lists_ACB-2DCLIN-2DCHEM-2DGEN.html&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=cMxp_NanXU8H1bMHft0ynXNqWBO9iOXZ39XRyBZ8egc&e=
> List Instructions (How to leave etc.)
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.jiscmail.ac.uk_&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=rZZbQTBaSsZV_YDduI9RBB11sTw04YoR2N1dzUqzMag&e=
>
>
> ------ACB discussion
> List Information-------- This is an open discussion list for
> the academic and clinical community working in clinical
> biochemistry.
> Please note, archived messages
> are public and can be viewed via the internet. Views
> expressed are those of the individual and they are
> responsible for all message content.
> ACB Web
> Site
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.acb.org.uk&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=ASzVuUmIgFDfaCCPNg6C4bgK3LpvhQhHVI9iLJIaxRU&e=
> Green Laboratories Work
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.laboratorymedicine.nhs.uk&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=3--mLJT9NarSD613B7aQMMDh0Xri-UDmXRPZ6T9r1rU&e=
> List Archives
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.jiscmail.ac.uk_lists_ACB-2DCLIN-2DCHEM-2DGEN.html&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=cMxp_NanXU8H1bMHft0ynXNqWBO9iOXZ39XRyBZ8egc&e=
> List Instructions (How to leave etc.)
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.jiscmail.ac.uk_&d=AwIFAg&c=SgMrq23dbjbGX6e0ZsSHgEZX6A4IAf1SO3AJ2bNrHlk&r=_4rCeX3TSQgrdhhwEl4yDs13b8mZhuDoiRSP4oKKuU4&m=AOWGrF-KHy8M7WIW5Km5Z9khIGSuCxq_XCYo4Zjn1Ms&s=rZZbQTBaSsZV_YDduI9RBB11sTw04YoR2N1dzUqzMag&e=
>
>
> ------ACB discussion
> List Information--------
> This is an open
> discussion list for the academic and clinical community
> working in clinical biochemistry.
> Please
> note, archived messages are public and can be viewed via the
> internet. Views expressed are those of the individual and
> they are responsible for all message content.
> ACB Web Site
> http://www.acb.org.uk
> Green Laboratories Work
> http://www.laboratorymedicine.nhs.uk
> List Archives
> http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html
> List Instructions (How to leave etc.)
> http://www.jiscmail.ac.uk/
>
> ------ACB discussion List
> Information--------
> This is an open
> discussion list for the academic and clinical community
> working in clinical biochemistry.
> Please
> note, archived messages are public and can be viewed via the
> internet. Views expressed are those of the individual and
> they are responsible for all message content.
> ACB Web Site
> http://www.acb.org.uk
> Green Laboratories Work
> http://www.laboratorymedicine.nhs.uk
> List Archives
> http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html
> List Instructions (How to leave etc.)
> http://www.jiscmail.ac.uk/
>
> ------ACB discussion List Information--------
> This is an open discussion list for the academic and clinical community working in clinical biochemistry.
> Please note, archived messages are public and can be viewed via the internet. Views expressed are those of the individual and they are responsible for all message content.
> ACB Web Site
> http://www.acb.org.uk
> Green Laboratories Work
> http://www.laboratorymedicine.nhs.uk
> List Archives
> http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html
> List Instructions (How to leave etc.)
> http://www.jiscmail.ac.uk/
> <Lipid correlation.jpg>
------ACB discussion List Information--------
This is an open discussion list for the academic and clinical community working in clinical biochemistry.
Please note, archived messages are public and can be viewed via the internet. Views expressed are those of the individual and they are responsible for all message content.
ACB Web Site
http://www.acb.org.uk
Green Laboratories Work
http://www.laboratorymedicine.nhs.uk
List Archives
http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html
List Instructions (How to leave etc.)
http://www.jiscmail.ac.uk/
|