Several
years ago, we published notice of the first reasonably successful transplantation
of pancreatic islet cells, for reversal of type 1, insulin-dependent diabetes.
First used at the University of Alberta in Edmonton, Canada, this "Edmonton
Protocol" makes use of new anti-immune medications, and has indeed enjoyed
a far higher apparent success
rate than any previous islet transplant methodology.
Once the initial report, from the research team in Edmonton, appeared (June 2000),
plans were made for a multi-center trial, to see if results could be replicated
at other institutions. This is standard procedure for any promising new treatment.Conducted
by the Immune Tolerance Network (ITN) this study, the ITN Multicenter Study,
will run through 2003, and, after a minimum two years of "following" patients,
will report, perhaps in 2006. But preliminary reports are coming in now, and
they are worth close
inspection.
"Is this the cure?" we asked in Voice, Vol. 15, No. 4, October 2000.
Statistics were excellent, percentage-wise, but actual numbers were very, very
small. This
is still the case--we are talking about only a handful of people. Statistics
are still excellent, but here's the
breakdown:
1. 36 participants enrolled in the ITN
Multicenter Islet Trials.
2. Two withdrew voluntarily because of
side-effects from immunosuppression.
3. Three had three transplants each (maximum allowed) but have not yet achieved
insulin independence. It is possible some or all may eventually achieve this
goal.
4. Six participants' first transplant failed--so they are not eligible for "top
up" additional transplants.
5. Thirteen participants have not yet
completed the process.
So, any discussion of "success" at this stage is based on 23 individuals--and
upon completion, will be based on 36. When we remember that data on the long-term
dangers of Rezulin did not emerge until after a million prescriptions had already
been written for the drug, the dangers of over-generalization from too small
a statistical sample become
obvious.
So what do we know? We know the "Edmonton Protocol" is the most successful islet cell transplant methodology, so far. We know that many who do not achieve insulin independence do realize a decreased need for insulin. We know the technique might produce real, long-term insulin independence (as in "the rest of your life"). It will take more time. This may be a cure for type 1 diabetes; it looks like it will be--but it will be years, of waiting, watching, and checking the health of test participants, before we know for sure.