Showing posts with label antigen typing. Show all posts
Showing posts with label antigen typing. Show all posts

Sunday, April 12, 2015

While my guitar gently weeps (Musings on the seduction of technology)

Updated: 13 April 2015
April's blog focuses on news items from TraQ's latest newsletter that have a commonality. 
  • The main item deals with a molecular assay to identify 35 red cell antigens from 11 blood groups. 
  • The other, included to illustrate the blog's theme but mainly here for fun, focuses on the clinical uses of platelet-rich plasma (PRP). 
I'll leave it to readers to ascertain what the stories have in common. The blog's title derives from a 1968 George Harrison ditty in the Beatles 'White Album'. 

 NEWS ITEMS
MUSINGS on MOLECULAR BLOOD TYPING 
Typing of blood group antigens at the molecular level has been in the works for years. Now it's moving beyond its original special uses because of technological advances, decreasing costs, and lobbying by vested interests. 

However, its cost-effectiveness is still unproven. Immucor's PreciseTypeTM HEA test costs ~$350 USD but that likely varies significantly depending on individual contracts. And any cost study I've read in journals like AABB's Transfusion is so dependent on assumptions as to be almost meaningless and needs to be read carefully and critically.

Also, molecular blood typing is not the be-all, end-all for the 100s of blood group antigens that exist, since not all are DNA-defined. But the list of antigens covered is impressive and includes nearly all clinically important blood group systems (see Further Reading). 

Regardless, molecular blood typing has no end of proponents, mild and strong. For example:
I wrote a blog on this topic years ago: 
  • Snip, snip the party's over (Dec. 2010) 
    • Suggest you read it later, if the mood strikes. My predictions have come true but they were no-brainers. 

Me Medicine
Now molecular blood typing is being marketed as personalised medicine, ie., the tailoring of medical treatment to individual characteristics of each patient. The idea derives from the 13-year, $3 billion Human Genome Project. For example, Immucor advertises PreciseType this way:
Makes it seem that anything less is substandard. Get with the program, health care providers, because it's all about me.

But many experts like Donna Dickenson, emeritus professor of medical ethics and humanities at the University of London and research associate at the HeLEX Centre, University of Oxford caution that
MUSINGS: PLATELET-RICH PLASMA (PRP) 
I'd read several news items over the years about PRP's use in orthopedics, particularly for athletes:
And recently the owner of a local restaurant I frequent mentioned that she had her own plasma injected into her knee but had to pay for it as it wasn't covered by Canada's universal health care system, at least for her. She said her knee caused a lot of pain (she's a 50-something server in the restaurant) but apparently it wasn't bad enough to be operated on yet. 

With that as background, recent news items on PRP's expanding clinical uses caught my attention. Medical tourism grows daily, at least for the rich. Seems Dubai now has more plastic surgeons per capita than any other city in the world and hopes to attract half a million medical tourists by 2020. 

The penis and vagina PRP nonsense was included just for fun. But really, Academy Award nominees got a coupon for a Priapus Shot? You cannot make this stuff up. 

BOTTOM LINE 
Okay, I lied because I'm sure you've gotten the blog's theme by now:
  • Where there's a buck to be made or an agenda to be advanced, clinical uses of diagnostic tests and products will inevitably expand well beyond what's evidence-based. 
TM poster-child for phenomenon? Intravenous immunoglobulin (IVIg). 

But what's surprising, at least to me, is how few voices, especially in the TM community, question the *expanded use* of innovations like molecular typing of red blood cell antigens under the guise of me-medicine. Particularly since our so-called 'thought leaders' are so into evidence-based these days. 

I understand why advances that help solve real TM problems are celebrated. But why the uncritical approach? Is it because blood typing at the molecular level is 
  • A marvelous innovation and all want to be seen as 'with-it' hipsters on DNA's bandwagon? Versus being old-fogeys who resist change? 
  • Way to develop a business line and maximize earnings in a shrinking field like TM in age of 'blood conservation 'über alles', e.g., AABB? 
  • Outright self-interest for those who specialized in molecular technology and need to maximize their career's life-span?  
  • Seen as eliminating humans from the equation, such as interpreting serological test results, thus must be good? 
  • High-throughput automated innovation, another way to decrease costs by eliminating those pesky creatures, aka staff, with their costly salaries, benefits, and pensions? 
    • Better to give money to international companies than keep staff, aka tax payers and community builders, employed at home?
    • Plus many staff are probably contemplating retirement anyway and eliminating their jobs will help make that decision easier? 
  • Viewed as best thing since sliced bread, not just a significant innovation with specific uses, motivating proponents to abandon whatever critical thinking skills they ever had?  
BOTTOM LINE 
Personally, I wholeheartedly agree that molecular blood typing is a useful, indeed marvelous, advancement that will make blood transfusion safer for many. Celebrate its potential but please don't promote it beyond clear clinical uses so that anything else seems sub-standard, as in this over-the-top headline: 
  • 'Boston Children’s Hospital ends BAD BLOOD between donors, patients' (Emphasis is mine)
FOR FUN 
'While My Guitar Gently Weeps':
  • #136 on Rolling Stone's "The 500 Greatest Songs of All Time"
  • #7 on its list of 100 Greatest Guitar Songs of All Time
  • #10 on its list of The Beatles 100 Greatest Songs. 
While my guitar gently weeps (Paul McCartney and Eric Clampton tribute to George Harrison, Queen's Golden Jubilee, London 2002) 
I don't know why nobody told you 
How to unfold your love 
I don't know how someone controlled you 
They bought and sold you. 

I look at the world and I notice it's turning 
While my guitar gently weeps 
With every mistake we must surely be learning 
Still my guitar gently weeps 

As always the views are mine alone and comment are most welcome.

FURTHER READING 
References for those who want to delve further into the blog's topics. 
Molecular blood typing
Nice overview: Denomme GA. Prospects for the provision of genotyped blood for transfusion. Brit J Haem 2013 Oct;163(1):3-9.

For molecular blood typing in detail, see these papers from 2009. Info overload but fascinating insight into predicting the future (All papers free full text): 

Molecular blood group diagnostics.Transfus Med Hemother. 2009 Jun; 36(3): 154–155.(editorial) 

Five expert opinions on the question ‘Will genotyping replace serology routine blood grouping in the future?’ 
Interpretations are mine. (Author origins refer to where they worked then, not necessarily nationality.) 
  • Opinion 1: Only partly. Unlikely unless... (Germany) 
  • Opinion 2: Probably (Switzerland) 
  • Opinion 3: For some applications (Austria) 
  • Opinion 4: Personalized versus Universal Blood Transfusions – Combining the Efforts: Probably but in combination with enzymatic conversion (ECO) to remove A and B antigens (Sweden) 
  • Opinion 5: Yes (Netherlands) 
Platelet-rich Plasma 

Monday, December 20, 2010

Snip, snip, the party's over? (Musings on the seductive rise of DNA typing of blood groups)

Updated: 28 Jan. 2017 (Fixed broken links)
December's blog's title comes from
  • A song by Willie Nelson: The party's over
  • Single-nucleotide polymorphism or SNP (pronounced snip), the basis of most blood group DNA typing. Simply put, a SNP is a DNA sequence variation that occurs when a single nucleotide in the genome differs between members of a species or paired chromosomes in an individual.
The use of seductive is tongue in cheek. Not sure if I mean 'harmful but enticing'. Perhaps insidious would be apter, i.e., 'developing so gradually as to be well established before becoming apparent'?

The blog discusses
  • Increasingly cozy relationship between TM professionals and the biotechnology industry;
  • Molecular typing of blood groups and its uses;
  • What DNA typing potentially means for the TM laboratory's work force;
  • A futuristic farce on where all this might lead.
BLOG'S ORIGIN

The idea for this blog came from these sources:
  1. Announcement in the AABB Weekly Report (17 Dec. 2010) of a new section in Transfusion devoted to blood group genomics with Connie Westhoff, currently director of genomics and immunohematology at the New York Blood Center, as the section's associate editor.
  2. DNA typing resonated because a recent blog (Aug. 2010) discussed Immucor' s investment in DNA typing, specifically its purchase of Bioarray Solutions in Aug. 2008: Goldfinger's filings, a customer's toolkit (Musings on business intelligence) and Immucor's belief that "molecular immunohematology will revolutionize blood bank operations."
  3. By chance, in researching a case study, I had just read two articles on molecular typing, one co-authored by Westhoff:
Westhoff CM, Sloan SR. Molecular genotyping in transfusion medicine. Clin Chem 2008;54(12): 1948-50.
Reid ME. Transfusion in the age of molecular diagnostics. Hematology 2009.

FYI: Marion Reid, a legend at the New York Blood Center and recipient of the 2006 International Woman in Transfusion Award.
COZY ARRANGEMENTS?
Interestingly, the Westhoff and Reid papers above list author involvement with Bioarray Solutions (and its earlier name, Bioarray), a company whose products DNA type red cell and HLA antigens.
Westhoff and Sloan paper's disclosure of potential conflicts of interests:Consultant or Advisory Role: C.M. Westhoff, BioArray, Ltd. and Immucor Inc. S.R. Sloan, Bioarray Solutions.

Reid paper's conflict-of-interest disclosure: The author receives research funding and royalties from patents from BioArray Solutions.
As evidenced by these examples, world class TM professionals often advise biotechnology companies and Bioarray Solutions has its share of respected advisors. Besides the three already mentioned, I came across others. It's accepted that industry needs input from professionals and the practice is common.

Of note, industry financing involving direct and indirect payment (consulting, food, travel, product samples, you name it) is estimated as high as $29 billion/year.

SO WHAT?
Questions to ponder:
  • Could consulting for a biotech firm, presumably for a fee, influence a person's perspective towards the technology in general?
  • How about earning royalties for a patent used by the company?
  • Could association with a company, current or past, influence a person in a role as editor of a journal section specifically dealing with research and developments in the company's field?
What happens when respected, leading experts, individuals who are the targetted clients of a particulate technology, also advise the companies as consultants and later serve as gate keepers of peer review for what is often company-sponsored research?

My gut tells me that something could happen, despite the obvious integrity of those involved. Arrangements, many of which are not transparent, seem too cosy to generate confidence in the system.

Can anything be done? Perhaps not. 

DNA TYPING - TM USES
To quote from Immucor's 2010 SEC Form 10-K report in discussing Bioarray Solution's DNA technology:
"In many countries, blood pre-transfusion testing is limited to the prevention of transfusion reactions and not for the prevention of alloimmunization, which occurs when antigens foreign to the patient are inadvertently introduced into the patient’s blood system through transfusions. If alloimmunization occurs, the patient develops new antibodies in response to the foreign antigens, thereby complicating future transfusions.
By using multiplex, cost-effective molecular testing, our molecular technology allows testing to prevent alloimmunization for better patient care."
Not unsurprisingly Immucor focuses on preventing alloimmunization, as this use would considerably expand profits. As I noted in the earlier blog: "In a consumer society, if a real need does not exist, companies try to create one."

So what are the legitimate uses of molecular typing to determine blood groups?

Scenarios where DNA typing could prove useful include these scenarios (see Further Reading for more details of each scenario):

1. Recently transfused patients with unexpected antibodies who have two red cell populations.

2. Patients with a positive direct antiglobulin test where available typing antisera reacts only by the indirect antiglobulin test.

3. Fathers of infants carried by Rh negative woman with anti-D where the father is Rh positive.
DNA typing the father for the RhD gene can determine homo- or heterozygosity for D and indicate if the fetus is definitely D+ and should be monitored.
If being D-negative is possible, the fetus should be Rh typed using fetal DNA from cells obtained by amniocentesis or by testing cell-free, fetal-derived DNA in maternal plasma.

If the fetus is Rh negative, mother and fetus do not need to be monitored.
4. Pregnant women who appear to be weak D, in order to differentiate between weak D and partial D, since usually only the latter can make anti-D. Potentially, Rh immune globulin could be given only to females with a D variant who are partial D.

5. Extended phenotype matching of donor blood for patients with sickle cell disease.

The above scenarios are not exactly pressing. Many situations have work-arounds or present limited safety risks to patients. Granted they offer useful adjuncts to serologic testing.

As to the nuts and bolts of pretransfusion compatibility testing, routine ABO and Rh typing do not warrant molecular methods, nor does preventing alloimmunization in general as Immucor would have its investors believe.

WORK FORCE IMPLICATIONS
Although molecular methods for typing red cell antigens are available in some locations, today the technology is mainly used by reference laboratories to supplement traditional serologic typing methods done 'in the trenches'.

Despite good progress, significant practical and scientific limitations remain and the issues are complex, as discussed in the papers in Further Reading. Seltsama and Doescher cover the scientific issues extensively. The 'high-throughput platforms' mentioned by adherents are not quite ready for prime time live in your neighbourhood blood centre and transfusion service.

Thus, work force effects will not be snip-snip, where SNIP is defined as
  • To cut, clip, or separate with short, quick strokes
Rather the SNP cut will be long and slow before staff hemorrhaging begins. But begin it will.

All TM laboratory professionals know that serology is in its last gasps. This is shown by the paucity of immunohematology papers in journals such as Transfusion. For example, December's issue has two and neither deals with red cells.

Rest assured that once 'high-throughput platforms' become widely available for molecular typing, regardless of whether sound scientific rationales exist, antigen phenotyping of all kinds will be taken over by molecular methods. It's simply too seductive, especially with so many TM leaders on side with the program.

As with automation, vendors will justify initial costs or high ongoing maintenance and supply charges (if a 'razor and blade' business model is chosen) with the promise of "reduced headcounts"  -  eliminating jobs for people in the community in favour of sending money to commercial enterprises elsewhere, where corporate profits are the main concern.

'SUGAR PLUM FAIRYLAND'
Seeing as it's the festive season, let's peek into a futuristic world populated by sugar plum fairies. I've mined some stereotypes (hope they bring a chuckle) and all is written with warm goodwill.

Here's the premise. What if companies pushing automation, other high throughput instruments, and information systems to support them have their way and almost every transfusion service laboratory job is eliminated?

In such a fairyland:

DNA typing platforms will match patients with donors for all major blood group antigens and pretransfusion serologic tests will become redundant.

Labs will be staffed by inexpensive 'multi-skilled workers' with no formal qualifications, all supervised by technical specialists (perhaps one per shift) now in a 'leadership role better aligned with their skills'.

Lab technologists / scientists will be free to take a buyout, a generous offer of $100 per year worked. They will, however, be forced to hawk their collection of syringes and tourniquets on street corners to finance a nursing education, which they can now consider since nurses no longer have much patient contact.

Since gowns became de rigeur for personal protection in the lab, they will sport white lab coats and happily be mistaken for physicians who have long claimed the lab coat as their uniform of record despite most never having set foot in a lab (too dark and dingy down in those basements). 

On the clinical side, other technology (bar code scanners, RFID, and the like) will ensure positive patient and donor unit identification. Smiling robots will administer blood transfusions, leaving nurses free to rant about newbie residents and those nitpicking idiots in the lab, have wild sex in the closets, and fantasize about Nurse Jackie one day killing Dr. House.

Yet more technology in the form of biosensors implanted in patients will decide when blood transfusion is warranted using programmed best practice guidelines, determine which components are needed, measure their effectiveness post-transfusion, and communicate all via wifi to a central information system nicknamed Big Bro (BB for short).

TS medical directors will sit in their offices playing on iPads with100s of fun apps all tailored to what Gregory House would be like as a hematologist versus a hematopathologist.
  • On breaks, the wunderkind millennials will tweet each other about how to pay off student loans before retiring.
  • About-to-retire boomers will obsess about stock portfolios.
  • Late Generation Xers will text about how, if they hear once more how great the Beatles and 1960s were, they will throttle their parents.
SMALL MERCIES
In the absence of sugar plum fairies, when reduced serologic antigen phenotyping eventually occurs, the serologic mainstays will remain as they are now, antibody detection and identification. Thank goodness for the immune response. The party's not quite over...."These are still the days, my friends".
Have a well deserved, fun-filled and relaxing holiday season with friends and family. And may the farce be with you....

FURTHER READING

Reid ME. The Rh antigen D: a review for clinicians. Blood Bulletin 2008 Apr; 10(1).

Reid ME. Transfusion in the age of molecular diagnostics. Hematology 2009.

Seltsama A, Doescherb A. Sequence-based typing of human blood groups. Transfus Med Hemother. 2009; 36(3): 204–212. Published online 2009 May 14.

Westhoff CM, Sloan SR. Molecular genotyping in transfusion medicine. Clin Chem 2008;54(12): 1948.

As always the views are mine alone. Comments are most welcome BUT, due to excessive spam, please e-mail me personally or use the address in the newsletter notice.