[sharman]

V More Stuff on ADCT

Finally, some thoughts and issues and new developments with ADCT.

When you are doing ADCT not in conjunction with a disectomy, the first question is where to harvest the cells from. It seems to me, the harvest should be from very healthy discs, not the damaged one. While mucking around with a healthy disc always introduces a new risk factor (but hey, we do it in provocative discography), it seems foolish to me to further harass the compromised disc by using it as a donor site.

Technologies now under development may soon allow the harvesting of cells from less vulnerable sites. There's a patent application I googled up that talks about using gene therapy to turn chondrocyte cells harvested from other joints/cartilage into proper nucleus chondrocytes. And, at the University of Manchester, trials may be underway this year on a technology to turn mesenchymal stems (adult stem cells) harvested from the patient's marrow into nucleus chondrocytes, which can then be cultured for implantation. (Note, this seems a different procedure from a disappointing 10-patient study undertaken by Microspine (no positive results reported at all), where stem cells were injected directly into the disc.)

(Of course, the U.Manchester surgeon (Richardson) then throws cold water on straight-up ADCT: "Cells from degenerate discs are not suitable for tissue engineering..." Wonder what he thinks about harvesting from healthy cells?)

If you're going to do the ADCT in conjunction with another invasive therapy, optimal timing becomes an interesting decision. Is it best to do the SED/abrasion/whatever first, allow the disc to heal, and then transplant? Or do the SED/abrasion, etc. when you can simultaneously inject the new cells? Right now, I'm leaning toward the latter. First of all, it's one less time you're poking a hole into the disc--presumably, you can do the injection through the same cannula you use for the abrasion, etc. Second, if we're going to be poking around in a traumatic fashion, scraping and removing things, especially if a volume of material might be removed, I like the idea of immediately providing new chondrocytes to start the rebuilding.

(Where ADCT is done in conjunction with a discectomy, three months is allowed between for healing. But there, the invasive discectomy is going to happen any way, that tissue is going to be used for the culture, and there's no way to change the order of the procedures: a discectomy, followed by at least a month for the cells to culture, so may as well make it three for optimal healing. So that practice and experience does not, IMO, have any bearing on the optimal process for ADCT not performed as an adjunct to discectomy.)

One last rambling thought about ADCT. You can probably tell, I really want this thing to work, and I have to try to keep a reality check on my enthusiasm. I've just had a chance to talk at length with Mark. Let me try to distill the pros and cons, the hopeful stuff and the caveats:

1) It is sobering that there is, in Mark's words, no 'buzz' about this procedure--it's been out there 10 years now. I want to believe this is because it is only a small patient population that can benefit, and because there is little patentable technology; hence, there is little money for trials and marketing.

2) It seems too good to be true, that you could heal up a chronic and stubborn condition like low back pain, just by culturing and reinjecting the patient's own cells. Nonetheless, there is a real track record of success building in the closely related field of knee/hip etc cartilage regeneration.

3) Is it an acceptable risk to harvest cells from healthy discs? If not, then it's a couple more years' wait for stem cell or similar technology to culture nucleus chondrocytes from less vulnerable tissue (bone marrow, joint cartilage). I have yet to talk to a surgeon who does this procedure; I may find I cannot find anyone willing to undertake the procedure except in conjunction with a discectomy.

4) And if you want to combine ADCT with other therapies, good luck finding a doctor or clinic who is willing to do, and is proficient in, both techniques.

There! I do believe I've punched myself out. I look forward to any thoughts or info any one else would care to impart!