Kappa Free Light Chains

The bad news is that, in the latest round of blood tests, my kappa free light chain number spiked, to 40% above the top end of the normal range. The good news is that this is not really bad news, yet.

To recap, plasma cells are in the business of producing the components of immunoglobulins, a.k.a. antibodies. These proteins are composed of chains of molecules, two "heavy" chains and two "light" chains each. There are two types of light chains, distinguished by the names "kappa" and "lambda". Normally, heavy chains and light chains are produced in more or less equal proportions, and assembled into antibodies. Light chains that have not been linked up with heavy chains -- "free" light chains -- are left floating around in the blood, and eventually are excreted in the urine. Too many free light chains of either type, or the wrong ratio between the two types, is taken to be an indicator of possible myeloma activity. In my case, the lambda number is normal, and the ratio is just under the top end of the normal range. The reason the ratio between the two types is significant is that there are conditions other than myeloma that can cause elevated numbers, but unlike myeloma, these conditions typically affect both types equally.

The oncologist is not yet worried, because this could be a one-time anomaly. Day-to-day variations in free light chain numbers can be substantial, affected by a number of factors, including for example hydration. To be considered truly significant, similar results would have to be repeated for successive tests. Beyond this, the numbers based on this blood test are not considered definitive; a much more accurate test, called "24-hour urine protein electrophoresis", would be carried out in order to justify taking any remedial action. I took this test not too long ago, and passed. So there is no cause for panic just yet.

A Penny For Your Stem Cells

As you may recall, the first big step in the stem cell transplant procedure that I underwent two years ago was the harvesting of my own stem cells. Over a period of several days I was given a drug (Neupogen) that stimulated the bone marrow's production of stem cells, and pushed them out into the blood stream. When there were enough of them out there, they were extracted (a process called "apheresis") and frozen for future use. This type of peripheral blood stem cell transplant, in which I was both the donor and the recipient of the stem cells, is called "autologous". In the other type of stem cell transplant, called "allogeneic", the donor and the recipient of the stem cells are different people. And according to the provisions of the National Organ Transplant Act, the donor must not be compensated for his or her role in the transaction.

The Act doesn't say so explicitly, though, because in 1984, when it became law, neither type of peripheral blood stem cell transplant existed. At that time, stem cells had to be extracted physically from the donor, in a process known as "aspiration" -- the same process I undergo when I get a bone marrow biopsy. It involves anesthetics, and big hollow needles that are pushed directly into the donor's bones. Except whereas just a small amount of marrow is quickly extracted for a biopsy, a great deal more must be taken for a bone marrow transplant. It's a lengthy, dangerous and painful process for the donor, which is why bone marrow donors have traditionally been difficult to come by, and why this older type of bone marrow transplant has been progressively replaced by peripheral blood stem cell transplants. But the anti-compensation provisions of NOTA have been assumed to apply uniformly to stem cells, irrespective of the method of their extraction, even though the law's text necessarily refers only to bone marrow extracted via aspiration.

Until now, maybe. Recently the 9th U.S. Circuit Court of Appeals ruled that stem cells extracted by apheresis are more akin to ordinary blood than to an "organ" -- it has always been possible to pay people for their blood -- and that therefore NOTA does not apply to stem cells extracted via apheresis. It hardly need be said that such a ruling is controversial -- it's thought by some to represent a "camel's nose" for the eventual development of a market in organs -- and is probably headed for final resolution by the U.S. Supreme Court, if Their Honors are interested.

The New #27

At long last I have the long-term replacement for tooth #27. On Thursday I returned to the dentist's office for the "delivery" (official dentist terminology) of the crown. He worked quickly, unscrewing the temporary insert and screwing in the real abutment. As an aside, you haven't lived until a dentist has climbed into your mouth to tinker in there with a wrench, as if he was a mechanic changing the plugs on a mid-size sedan. Fitting the crown required a couple of attempts, with adjustments to the shape made with a grinder. When he was satisfied, the crown came off one last time, and a semi-permanent cement was applied to the abutment. The cement is not the strongest dental cement available, so that the crown can be removed later, if necessary for some reason, without destroying it. The crown was then mounted for the last time, and the cement allowed to set for a couple of minutes. Finally came the most painful part of the process: The dental technician had to clean up the excess cement sticking around the lower edge of the crown, using a sharp implement; this caused substantial irritation to the surrounding gum.

Thus ends the strange and sorrowful tale of tooth #27, about which nothing more needs to be said, I hope.

One Step Removed From The Crown

Progress has seemed glacial all along, but today saw one step closer to the end of the saga of the late lamented tooth #27. I traveled to the dentist's office to have the impression taken for the implant's crown. The man used a grinder on the adjoining teeth to get a bit of clearance, unscrewed the oral surgeon's temporary abutment and replaced it with the real, permanent one, and then stuck an undersized version of your typical caulking gun into my mouth. The solidified result of the squishy stuff that came out of it will be sent off to the lab to be used to manufacture the crown. I will return on December 22 to have it installed.

Implant Check

Today I returned to the office of the oral surgeon, to have him check on the implant that he had stuck into my lower jaw in place of tooth #27, back at the beginning of August. After tapping on the abutment and trying to move it around, he expressed satisfaction that the implant and the bone are getting along well with one another, but decided that the gum in the vicinity needed "reshaping". After giving me a local anesthetic, he brought out some kind of small laser torch; shortly thereafter, I could smell my own flesh burning. It's not a scent I would like to become familiar with. I'll have a bit of pain for a few days, but in a couple of weeks, assuming that everything heals up nicely, I'll be ready for the crown.

A Year At Work

It's a little hard for me to believe that is has been so long already, but as of the beginning of November, I have been back to work for a full year. Upon review, it seems that the concerns I expressed at that time turned out to be mostly groundless. I believe that I am now functioning mostly as I did prior to the beginning of my crisis, almost two and a half years ago. The only differences are that I still have to take the occasional nap during the day (much less frequently than a year ago, though); and of course I have many more medical appointments than before. It remains to be seen how long this period of relatively comfortable stability can continue.

Hearing Check

For several years now, when watching a movie on DVD, I have felt compelled to turn on the "captions for the hearing-impaired". I do this in the interest of being able to comprehend the dialogue, which can sound muddy and indistinct. I can simply turn up the volume to achieve the same end, but that makes the music and the explosions too loud. This problem seems to have worsened during the past year or so, so recently I obtained a prescription for a hearing evaluation from my primary care doc. She noted that chemotherapy has been known to affect hearing, and we agreed that in any case it would be good to at least establish a baseline, for future reference, even if there is nothing else to do about the problem for now.

Today I travelled to downtown Wilmington for my evaluation. There was really not much to this; I spent more time filling out forms than I did being tested. The audiologist first simply did a visual inspection, to ensure that there were no physical obstructions blocking the ear canals. She also did some kind of pressure test, in an effort to verify that there was no water in there, behind the eardrums. For the actual test, I was seated in a soundproof room, wearing a pair of earphones and holding a pushbutton device. I was instructed to push the button whenever I thought I could hear any tone, however indistinct, coming through the earphones. Of course I was fed tones at a wide range of volumes and frequencies. Finally, I was asked to listen to and repeat back a number of one-syllable words; these were obviously designed to detect any inability to distinguish between similar-sounding consonants.

The audiologist indicated that the test did not reveal any substantial loss of hearing. There is some deterioration at higher frequencies, which could account for some of my difficulties. But at this point there is nothing wrong that makes intervention necessary or desirable.