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Typical Clinical
Scenarios
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- Autoimmune Hypophysitis affects young females most frequently
In 81% of cases, Autoimmune Hypophysitis
affects women. Several autoimmune processes prefer females as
their favorite "target". This high prevalence probably
correlates with genetic and environmental factors. Because autoimmune
processes are more prevalent after puberty or near menopause,
researchers think that estrogens may represent one of the multifactorial
triggers in developing autoimmune disorders. This theory can also
explain why, sometimes, estrogen treatment may worsen some autoimmune
diseases (Systemic Lupus Erythematosus, SLE, for example). (learn
more about autoimmunity)
- Females are affected especially in the early
postpartum period
Autoimmune Hypophysitis usually becomes clinically
evident after a delivery, in the early postpartum period. The
reason for this, is not completely known, but has been observed
in other autoimmune diseases, such as in autoimmune thyroid diseases.
The most accepted theory is based on immunological and hormonal
bases. During pregnancy, the autoimmune system turns off some
of the physiologic ways to discovering the exogenous enemies,
because a tolerance of the fetus (half belongs to the mother,
but half to the father) is needed. After delivery, the immune
system turns its defenses back on. This can also produce an attack
against the self, as an autoimmune reaction occurs. The role of
the hormones in triggering autoimmune disease has been studied
for a long time. The hormonal changes that happen during pregnancy
and after delivery, may influence the autoimmune overreaction,
but these putative sex differences need to be well established.
- Early symptoms are visual impairment and headache
The autoimmune process produces the enlargement
of the pituitary, because a lot of autoimmune cells, such as lymphocytes
and others hematopoietic cells, migrate into the pituitary tissue.
The gland situated just behind the optic chiasm, starts to
press the optical structures. The result of this anatomical injury
is a visual impairment: the patients reports that they cannot
see things as well. Specifically, the peripheral part of the field
of vision decreases, determining the clinical condition also named
Bitemporal Hemianopsia.
Hemianopsia derives from the old Greek: "hemi" means
a half and "anopsy" means without vision; "bitemporally"
refers to the fact that both halves near the temporal bones of
the skull are deficient. For this reason ophthalmologists are sometimes
the physicians which diagnose the disease first, because the patient
reports impaired peripheral vision.
Another frequent symptom is headache. This
is probably caused by the compression that the inflamed and enlarged
gland produces on the dura mater, the membrane covering the brain.
- Clinical history: Maria's case
Maria is a 28 year old female. She married
Paul two years ago, and became pregnant in September. During the
pregnancy she had no problems. She delivered a beautiful son,
Mike, in June. Some weeks after the delivery, she started not
feeling well. She noted that sometimes she cannot watch TV well,
and sometimes she bumps into doors. She also has a persistent
headache, and does not sleep well at night; she thought she was
so tired during the day because of this. She went to her physician
and he suggested having blood tests done and referred her to an
optician. The blood tests were normal, so Maria decided to go
to her optician. She didn't find anything wrong inside the patient's
eyes, but there was a severe visual impairment on the field of
vision examination. The optician thought that Maria needs radiological
study of the brain.
- Hypophysis examination by radiological assessment
represents the most useful cost/benefit study for pituitary enlargement
During the last 20 years Computed Tomography
(CT) and Magnetic Resonance Imaging (MRI) have been used to study
both vascular and organic diseases of the brain. They are also
routinely utilized in studying the pituitary; especially MRI which
has a very high sensitivity and resolution factor. These radiological
machines unlikely have a lower specificity. Sometimes pituitary
tumors and inflammation (enlargement), as well as occurs in Autoimmune
Hypophysitis, are not differentiable. In fact, both can appear
as hyperdense images, after a contrast medium is injected.
But they are useful in testing if a disease has involved the pituitary,
or when visual impairment occurs.
- Usually tends to recover
spontaneously, but sometimes a persistent, partial or total, pituitary
defect can remain
Autoimmune Hypophysitis differs from other autoimmune diseases. The visual impairment
can represent the proof of the gland enlargement, without any
sign of hormonal defect. But, especially when the field of vision
contraction is the first symptom, a wrong diagnosis can be made,
because of the radiological misunderstanding. Clinical history
(recent pregnancy, sex, and a family history for autoimmune disease)
can help in the correct handling of the patient.
Sometimes the autoimmune process is so aggressive
that most of the gland is injured. In this case a hormonal defect
is present, because pituitary is no longer able to produce those
hormones necessary to regulate the function of the peripheral
endocrine gland. The most important and dangerous hormone deficiency
is that which affects the adrenal glands. In fact, a rapid and
severe develop in cortisol production, can cause cardiovascular
failure (hypovolemic shock) and subsequently death. But also thyroid
and gonadal functions could be affected, and respectively hypothyroidism
or a precocious menopause (with infertility) can develop. When
the clinic history suggests that one or more hormones are defective,
a functional study of the gland is needed. The hormone defect
can be transient or, unlikely, persistent. In the last case, a
hormone replacement therapy is needed for the rest of the patient's life.
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