Alveolar epithelial cells page 312 transmission is

alveolar epithelial cells
(page 312).
-Transmission is not
well understood
(Epocrates)
-Slow and
progressive onset
-dyspnea with a
gradual onset, getting
worse over the
course of several
weeks.
-fatigue, weight loss,
poor appetite
-Chest x-ray will
show a butterfly
pattern of infiltrates
that extend from the
center of the chest
Infection in the lung starts
with the multiplication of
the organism in the
alveoli. As infection
progresses, alveoli fill with
exudates, there is type 2
pneumocyte hyperplasia,
and mononuclear cells
infiltrate the lung.
In patients with AIDS,
there are larger numbers
of Pneumocystis
organisms in the lungs
and fewer inflammatory

(lecture notes). cells than in patients with
Pneumocystis pneumonia
(PCP) who are HIV-
negative.
mycobacterium
avium complex
(MAC)
-Acid fast bacteria,
often found in the
environment-soil, water,
and animals
-The cell wall contains
long-chained glycolipids
(that make the wall
thick) protect these
facultative intracellular
bacteria from lysosomal
attack
-90% to 95% of
diseases in AIDS
patients
Fevers, night sweats,
weight loss, anorexia,
and
lymphadenopathy
(lecture notes).
After entry into the
body, MAI organisms
colonize the
respiratory and GI
tracts and invade and
multiply within
macrophages. This
phagocytosis and
processing of
antigens by
macrophages triggers
a complex immune
response that
includes further
activation of
macrophages as well
as the release of
cytokines such as
interleukin (IL)-12,
interferon gamma and
tumor necrosis factor
alpha.
-In immune deficiency
patients this can lead to
unimpaired multiplication
of the organisms within
macrophages and
subsequent
dissemination.
cytomegalovirus
(CMV)
CMV is a member of
the herpes virus family.
It contains a genome of
double-stranded linear
DNA, an icosahedral
viral capsid, and a viral
envelope protein that
includes the highly
immunogenic
glycoprotein B. The
most important
characteristic of
In a person with HIV
and a low CD4 count
the virus typically
infects the retina and
causes CMV retinitis-
potentially causing
blindness. (lecture
notes)
-CMV infected cells are
protected from both T-
cells, and NK cell killing
because it has down-
regulated MHC
expression
Once the virus is in the
cell
-it can inhibit cellular
DNA, RNA, or protein
synthesis, disruption of
lysosomal membranes,

herpesviruses, including
CMV, is the ability to
have latency following
primary infection.
Making it easier for
reinfection (epocrates)
resulting in release of
digestive lysosomal
enzymes
-Promotion of apoptosis
-fuses infected cells to
produce multinucleated
giant cells
-transformation of infected
cells into cancerous cells
causing unregulated
growth.
-alteration of the antigenic
properties, causing the
immune system to attack
the cell as if it were
foreign (page 320).