Islet Transplant - Day 75 - Roger Sparks

Transplant Status – Day 75

At day 75, an A1C blood test in the 5’s illustrates the potential life change this clinical trial offers Type-1 diabetics. But decisions remain for me.

75 days is an important milestone day in this islet transplant clinical trial.  The implanted islets have now had time to properly graft in my liver, and my immune system has had time to react, or not react, to the immunosuppression drugs I am taking.

I reported to the City of Hope for three half day sessions consisting of chemical and blood tests.  They took about 70 vials of blood in total.  At approximately 25 large vials per day, the lab nurses drawing the morning blood started to hate seeing me walk through the door!

I’m going to get a little med-geeky here, but I want to explain the tests and associated results a little.  I’m doing this in case you are diabetic, or have a diabetic in your family, and are interested in the details.

A1C Blood Hemoglobin Test

Every Type-1 or Type-2 diabetic knows the importance of A1Cs.  We have this test done once per quarter to determine how our diabetes is being managed.

The test shows our average blood sugar levels for the past two to three months. High numbers are bad, low numbers good.  Very high numbers are very bad.  Result ranges are typically:

Non-Diabetic: less than 5.7%
Pre-Diabetic:  5.7 to 6.4%
Diabetic:  6.5% or Greater

Over the years before my transplant I usually averaged about 7% to 7.25% as a Type-1 under pretty good control.

The Test Result:  My A1C for the last 75 days was 5.2%.

In 35 years as a Type-1, I’ve never had an A1C close to this level, and never dreamed I would see one.  I could almost not believe it.

Glucagon Stimulation Test

This test is really an indicator of how well the implanted islets are performing. It analyzes, on a minute by minute basis, their response to blood sugar changes in my body.

Islets – everyone’s islets – consist of two primary types of cells:

  • Alpha Cells, which react when they detect your body is low on glucose by producing a hormone called glucagon, which the liver then turns into glucose, then releases it into the bloodstream.
  • Beta Cells, which react to glucose in the bloodstream by producing insulin.  This in turn metabolizes the glucose into usable energy for your cells.

How This All Is Supposed to Work

When you eat something, it eventually becomes glucose in your bloodstream.  The beta cells are then supposed to react, producing insulin, and the insulin metabolizes the glucose so it can be used to feed your cells.

The Type-1 diabetic is always left with this glucose in the blood, and it can never get to the cells without an external injection of insulin.

In the non-diabetic, all these things work together to keep your blood sugar balanced and under control, and allowing all the cells in your body – including brain cells – to get the energy they need to operate properly. The transplant’s objective was to give me the responses of a non-diabetic, and to make it last as long as possible.

For this test they gave me an intravenous injection of glucagon to stimulate my liver into produciing glucose.  In turn this should stimulate my implanted beta cells to produce insulin, which then should metabolize the blood sugar, which they measure.  They took blood samples intravenously at short intervals, starting at a few minutes after the injection, for about an hour, to see how well this whole process was working in my body.

It occurred to me while this was going on that my liver hasn’t gotten this much attention since college, when my grandmother was so worried about it!

The Test Result:  My transplanted beta cells are reacting as they should.  They are producing insulin, but not quite enough for me to be “external insulin” free. The reason for this is not yet 100% clear, but it’s likely that it’s a quantity issue.  The quantity of islets remaining after the transplant, when many don’t survive the procedure and implant in the liver, may not be sufficient for my body size.

Because I’ve had no low blood sugars, it appears the transplanted alpha cells are working properly.

Summary Of Results

It’s important to remember the objectives of this clinical study, in priority sequence:

  1. To eliminate diabetic hypoglycemia – low blood sugars – and hypoglycemia unawareness.
  2. To dramatically reduce or eliminate the need for external insulin.
  3. To extend the effective time of the transplant, potentially to many years, by the use of new immunosuppression drugs and treatment, specifically T-Cell depletion.

So, these are mixed results – some very good, some slightly less, but none bad.

  • The A1C results were better than anyone could have expected.
  • The Glucagon results were pretty much what we expected, since I have been consistently requiring about 20 units of external insulin every day.  This is way down from over over 60 before the transplant, so definitely a dramatic improvement.

So What Happens Next?

My options, as they explained to me, are now:

  1. Have a second transplant now.  I can go back on the transplant waiting list, and, when a donor pancreas becomes available, have another transplant operation with more islets. We would then repeat the same process used over the past three months, with some adjustments in drugs.
  2. Stay as I am and see what happens.  I’m having no low blood sugars, have an excellent A1C, but am still requiring insulin by pump every day.  I can keep doing this, and see what, if anything, happens, or if the islet effectiveness gets less.  I also have the option to have another transplant at a later date.

In either case:

  • The islets may start to have reduced effectiveness at any time, as my immune system reacts to them or stops reacting to immunosuppression drugs..  We know that eventually this may happen, but no one really knows for sure how long they will last using the current clinical trial protocol.  That’s why they call it a clinical trial, intended to extend this period of time for as many years as possible.  I knew this going in.
  • I must continue to take immunosuppression drugs as long as any implanted islets are functioning.  These drugs can have unexpected consequences.  Again, I’ve known this going in.
  • I can continue to expect to be free of low blood sugar episodes as long as any alpha cell islets are functioning, irrespective of any increased insulin requirements, or decreased islets.  This is a really big deal.

But there is one, not so small, issue:

  • There are definite risks associated with a second transplant.  In addition to the normal risks with the surgery, my body may reject the second transplant because of unknown factors, or because they react with the prior transplant.  This has happened before, and would probably mean a rejection of all transplanted islets.  That would, in essence, put me back to where I was before the transplant, with low blood sugars, increased insulin requirements – the whole big mess.  That’s not a good thing to think about.

Summary

So why can’t anything be simple, right?  I asked them what course of action they recommended, and to please tell me what I should do.  However, they told me it’s my decision, and they’re not allowed to try and influence me.  I’ve asked for a lot more information, so I can make this decision with a full understanding of the issues involved, and am waiting for their answers now.

I’ll make this decision quickly.

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