The possibility of a T lymphocyte proliferation should be considered in
the 3 CLL patients whose lymphocytes did not bear detectable 5.1g.
particularly in the one with peculiar clinical features. However before reaching
this conclusion one should recall that in most CLL patients the immunofluorescence
of positive lymphocytes was strikingly fainter than that
observed in normal subjects. If the amount of S.Ig increases during the
maturation process of B lymphocytes, proliferating B lymphocytes blocked
at an early stage of maturation (see below) could carry subthreshold amounts
of S.Ig, and this could account for the negative cases