الفهرس 
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Abstract
Chronic suppurative otitis media is usually classified into two main
types; the first is the safe tubotympanic type with central perforation and
usually not associated with cholesteatoma, the second is the unsafe attico-
antral type usually associated with cholesteatoma.
Longstanding inflammations of the middle ear cleft occur in a multitude
of forms due to anatomic, physiologic and bacterial factors. However an
immunogenetic factor could not be excluded.
The HLA system is a cluster of genes located on the short arm of the
chromosome number 6 in human. It consists of HLA-A, B and C loci
which control class I antigens. HLA-D region contains also DR, DP and DQ
which control class II antigens. Factor B and complement control Class ill
antigens. The HLA system is considered as a genetic marker for the immune
system. The various mechanisms involved in the regulation of the immune
response of the body are under the control of the HLA system. During the
last few years, it has been found that the HLA system is deeply involved in
the susceptibility to a variety of diseases. This means that certain diseases
are associated with certain HLA antigens.
Several mechanisms were postulated to explain the association
between HLA antigens and specific disease. The most likly are: molecular
mimicry hypothesis, receptor hypothesis, modified HLA antigens
hypothesis, HLA linked genes hypothesis and the immune response
genes hypothesis.