Notes From Larry Dunn:

The %sat can definitely be high while the ferritin is
low.  This can be seen in several situations related
to HH.

Early warning sign:  A rising %sat is seen prior to
high ferritins.  It is the high %sat that indicates
that iron is in the process of loading in the tissues.
The ferritin will slowly rise over time.  This
happens to all who eventually overload on iron, but we
aren't aware of it so the iron-loading continues and
we are unaware until it is high enough to cause
symptoms.  This is why many recommend %sat be included
in all lab work for routine physicals, to catch it

Last stage just before being deironed: As the
phlebotomies are decreasing the ferritin levels, as
long as the body sees excess iron levels, the TIBC
will still be low, resulting in a high %sat.

In maintenance, ferritn is low, but %sat is high
again.  This is similar to the early warning sign
situation, only this time we are watching it and can
have a maintenance phlebotomy to bring the %sat back
down to a good level (whatever you and your doctor
agree to: some say less than 50%, some say less than