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Background:
Airway walls in
asthma present an
accumulation of
activated cells that
determine bronchial
structural changes
and disease
progression and
severity. During the
aging process, the
immunoinflammatory
response changes as
a consequence of
chronic antigenic
stress.
Objective: To
evaluate T-cell
subsets with
regulatory functions
associated with
asthma in elderly
patients.
Methods: A
group of 153
individuals (95 with
controlled asthma
and 58 healthy
controls) aged over
65 years was
studied. Blood
samples were
collected for flow
cytometry analyses
of CD3, CD4, CD8,
CD56, CD56CD8,
CD3CD4CD25,
CD3CD4CD25CD127,
CD4HLA-DR and TCRγδ.
Results:
Asthmatic patients
showed a
statistically
significant increase
in CD4+ T cells.
CD3CD4CD25high and
CD3CD4CD25highCD127high
cells were also
significantly
increased in
asthmatic patients,
while
CD3CD4CD25highCD127low
cells had similar
values in asthmatics
and in the control
group. CD4HLA-DR
cells were within
the normal range in
both groups. A
positive correlation
between
CD3CD4CD25highCD127low
and CD4HLA-DR was
observed and γδ T
cells were
significantly
decreased in the
asthmatic patients
compared to the
controls.
Conclusions:
Since T cells with
regulatory functions
were within normal
ranges or reduced in
asthmatic patients
compared to healthy
controls, at least
in basal conditions,
it can be speculated
that they probably
play a limited role
in chronic asthma in
elderly patients.
These data suggest
an absence of a
modulatory effect on
the inflammatory
response that
characterizes asthma
and allergy, which
in turn would
facilitate the
persistence of
disease in this
population.
Underlying
inflammatory
processes that are
involved in chronic
diseases associated
with aging could
provide an
additional
explanation for the
attenuated
differences observed
between asthmatic
and nonasthmatic
individuals.
Key words:
Asthma. Elderly.
Treg cells. T cells.
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