Tireoidite linfocítica - Repositório Aberto da Universidade do Porto

I ism, and "aberrant" expression of
antigens, particularly the DR phenotype
of the major histocompatibility com­
plex.
- Cytotoxicity does not seem to play
a fundamental role in the pathogenesis
of lymphocytic thyroiditis. The ten­
dency to hypothyroidism is caused
mainly by the convergence of genetic
and immunological factors; the change
of the topographical relation between
the thyroid follicles and the blood
capillaries may also influence the
functional hability of the thyroid
cells.
- The genes which control the aforemen­
tioned alterations may be associated
in different ways. Thus the clinical.
immunological and morphological
expressions of so-called thyroid auto­
immune disease may assume several
aspects: in some cases the assotiation
of genes determines the expression
of well defined entities (lymphocytic
thyroiditis. Craves' disease and primary
myxedema) whereas in other situations
the expressed alterations are not
sufficient to define a clear cut clini-
copathological disorder.
- Lymphoid infiltrate does not represent
a primary agressive process to the
thyroid. It may be related to an ecota-
xis phenomenon and is homologous
to the "mucosa-associated lymphoid
tissue" (MALT).
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