Pathophysiology
Hypersensitivity
pneumonitis
(
HP
)
is
a
spectrum
of
immune
-
mediated
____________________
characterized
by
diffuse
inflammation
of
interstitial
lung
,
____________________
bronchioli
,
and
alveoli
.
Inflammation
is
caused
by
prolonged
or
frequent
exposure
of
inhaled
antigens
generally
less
____________________
5
?
m
in
size
.
Although
offending
antigens
are
ubiquitous
,
____________________
incidence
of
disease
is
comparatively
small
.
A
two
-
hit
mechanism
has
been
proposed
in
which
individuals
either
genetically
____________________
to
the
development
of
hypersensitivity
pneumonitis
or
____________________
with
heavy
environmental
exposure
are
at
increased
risk
of
developing
the
disease
.
Antigen
exposure
constitutes
the
____________________
hit
,
resulting
in
disease
or
disease
progression
.
____________________
said
,
to
date
,
there
have
been
no
genetic
factors
consistently
____________________
with
hypersensitivity
pneumoniti
s
