14 October 2014

Needle in a Haystack

Has anything in your life, that seemed almost inconsequential at the time, come back 20+ years later as something with potentially enormous significance?

In 1992, I was less than a year out of college and settling in at my first real job. I was enjoying living on my own, and getting to know my way around Metro Detroit. Sometime early that year, our office building had the Red Cross in for a blood drive. I'd given blood on occasion in high school and college, and was comfortable with the process, so signed up for a slot and donated.

As I munched on the post-donation juice and cookies, I flipped through some brochures that had been put out from a related organization. This other group was building a registry of potential bone marrow donors; for a cancer patient with no compatible blood relatives --- especially full siblings --- available to donate, getting a hit through the registry could be their only hope. I honestly can't remember what in particular compelled me to fill out the form and apply to join the registry, but I did. I was most likely moved by the realization that I, having been adopted as an infant, almost certainly have no full blood siblings --- and certainly none that I knew of or could ever locate. I think that made it easy for me to empathize with the plight of someone in a similar situation. And, heck, let's face it: I was young and probably idealistic about potentially saving someone's life.

The registry deemed me healthy enough to join, and collected a small blood sample (they now use a cheek swab) to "type" me for the database. Human DNA has proteins called “Human Leukocyte Antigens,” or HLAs, attached to it. These HLAs serve as markers, to determine how good a match a potential donor is for a particular patient. There are a great many HLA markers --- but ten in particular that are especially important and that doctors examine to assess the degree of match. As I understand it, six (or three sets of two) of these are relatively easy and inexpensive to identify; these six are what go into each potential donor's registry record. When a patient needs a transplant, these basic six are used to greatly narrow the search. Anyone who makes the "short list" then submits a second blood sample and the expensive additional testing is done to identify his remaining four HLA markers. A donor and patient don't have to match on ten out of ten, but the more common markers they share, the more compatible their bodies are. And therefore the greater chance the patient's body will react well to the donor's tissue.

Two analogies, besides the obvious "needle in a haystack," come to mind: 

First, imagine pulling the lever on a slot machine, and needing ten different wheels to come up exactly the same in order to hit the jackpot. Or at least a large number of wheels coming up exactly the same before the machine pays out at all. I don't know how many variations there are on each HLA marker (or "slot machine wheel"), but any way you look at it...that's not a wager I'd put much money on. You'd need a awful lot of pulls on the lever (a very large database of potential donors) to get anything out of it. And the chance of any particular donor getting called for any particular patient would be small indeed.

Second, think about U.S. postal codes. The country is divided up primarily into five-digit zip codes, many of which cover large stretches of geography. But look closely at some of your mail and remember: zip codes also carry a four-digit extension. These additional four digits are of course used to tag addresses that share a much more limited geographic area. These are very helpful for getting the mail onto the right delivery truck, so it reaches the destination as efficiently as possible. I like to think of those first six HLA markers as being like the primary five-digit zip code. The additional testing is like determining the four-digit extension. The object is to find someone as geographically close to the patient as possible.

Over the last 22 years, I have never been asked to provide a second sample. In fact, for long stretches of time, I forgot I was even in the donor database. Sometimes I'd have a vague recollection that I'd registered with something or other, but I couldn't have told you what it was. I was a bit surprised when, a few years back, shortly after we moved to Michigan, they contacted me and asked me to update my contact information (which I gladly did). But as far as I know, following the analogies above, I've never even matched more than a few wheels on a slot machine...or even been metaphorically in the same county as a patient (let alone the same zip code).

Until now.

About a week and a half ago, late on a Friday evening, I received urgent email messages in both my personal and work email accounts, asking me to contact the registry immediately. I'd come up as a potential match for a 71 year old male in need of a transplant. I of course picked up the phone right away and called.

The representative explained that I'd been a close enough match on the first six HLA markers, they wanted to collect the additional four. She couldn't tell me exactly how many of the six I'd matched on, but her tone implied it could easily could be all six. ("You're more than in the ballpark," she said.) After determining that I was still interested in being a donor, she explained more about the process going forward. I would be asked to go to a qualified lab or medical facility to have blood drawn into two separate sets of vials. These would go to two different labs, which would determine (1) my degree of match and (2) whether I had any latent infectious diseases the patient could catch. The transplant process involves completely wiping out the patient's immune system before essentially replacing it with mine; if any sort of bug were to ride in with my donated material, the patient would have no defense against it at all. It could kill him in very short order.

She also described the donation process. Depending on the doctors' assessment, I might be asked to donate either bone marrow or to donate blood stem cells. Given the patient's age, the representative said it would more likely be the latter (she explained that children tend to respond better to marrow, while adults respond better to stem cells). The process involves a preparatory phase, in which the donor is given multiple injections, over several days, of a drug which stimulates stem cell production. The stem cells are then collected using a process that pumps blood out of one arm, through a scrubber, and back into the other arm.

I'm greatly simplifying the process, of course. And there is considerable discomfort associated with the procedure (and with donating bone marrow, of course, which would be done under anesthesia in an operating room). So why, after discussing the whole thing with Mrs. Yeoman Farmer, did I tell them I was still interested in going forward? Apart from it being a plain-and-simple good thing to do?

Lots of reasons.
  • Above all, Christian charity. A very particular person has a very particular and very desperate need, and only a very small number of people are in a position to assist. If it's determined that I'm his best match, I absolutely want to help him. How could I possibly pass by the road, and leave him in the ditch?
  • The donation process carries only a very small chance of complications, and therefore poses virtually no threat to my own health or ability to provide for my own family. We're not talking about donating a kidney.
  • As when I first registered, I still closely identify with and understand the plight of those who have no siblings available as potential donors. Given this patient's age, even if he has siblings, they may not be in any position to donate for him. 
  • Given the patient's age, he very likely has grandchildren. I can hopefully give those kids many additional years with their grandfather. I know my own kids would treasure that opportunity. And would greatly miss any of their grandparents, if that grandparent were to leave us prematurely.
  • A very good friend of our family, who lives near my parents and is close to their age, needed a bone marrow transplant while undergoing treatment for leukemia nearly 20 years ago. His disease was far advanced, and his doctors were running out of options. A match with a national registry (quite possibly the same one I'm registered with) identified the donor, who stepped forward to save our friend's life. Our friend made a complete recovery, and continues to live a full and active life today. How can I pass up the chance to do the same for someone else? None of us is an island; every one of us has friends. So does this patient. Being a donor means giving those friends additional years with that person they care about.
  • Finally, because our youngest child has Trisomy-21, she is at a statistically elevated risk of developing childhood leukemia. She's perfectly healthy now, but what would we do if she were ever to need a bone marrow transplant? And none of her blood siblings were a close enough match? We'd have to pray for a hit on the database --- and for a cooperative donor. I know how deeply grateful we would be to that person; he or she would be providing us a treasure beyond price. If there's any chance I can provide that treasure to another family, I want to do it. (As a related aside --- that same daughter needed transfused blood during her open heart surgery a year ago. The experience brought home to me the value of blood donation, and inspired me to begin regularly donating again after many years of neglecting to do so.)


I'm still not sure how this story will end, but I do hope that there will be additional installments. I provided my blood sample a week ago, so for now it's just a matter of waiting. Could be three weeks. Could be sixty days. The representative said there could be ten people who've been asked to provide an additional sample --- or I could be the only one. If it's just me, they need to make sure I'm close enough to the patient's type, and that I'm not unwittingly carrying something that could harm the patient. If there are multiple potential donors in the patient's zip code, they need to determine which of us is best. I might be, metaphorically, five blocks away --- but someone else might be living on his same street.

So ... stay tuned. And in the meantime, please give serious consideration to registering with Be the Match.

1 comment:

Anonymous said...

I clicked the link to Be the Match. Sounds like a Christian thing to do. Thanks for the info!