I do not know if this will help you or not but it was post here in the
past.
Harv

                                CHAPTER 2

                         UNDERSTANDING ARTHRITIS

  Genetic  markers  of  greatest  interest  to arthritis experts are the
proteins  known  as human leukocyte antigens (HLA), which are located on
the  surfaces  of  most  cells  in  the  body.  These markers were first
discovered  in  the  late  1960s.   Scientists  called  them  the  human
leukocyte  antigens  because  they  were  first  found on the surface of
human  leukocytes,  another  name for white blood cells.  These antigens
are  involved in the immune system's ability to distinguish normal cells
from foreign invaders.
   Scientists  first studied the human leukocyte antigens because of the
effect they had on organ transplants. A transplant was more likely to be
susessful if the donor and recipient had similar or matching antigens.
   Some years later, certain genetic markers were found to be associated
with  certain kinds of disease. These diseases included four major kinds
of rheumatic disease: ankylosing spondylitis, rheumatoid arthritis, some
forms  of juvenile arthritis, and Reiter's syndrome (a form of arthritis
that may develop as a complication of certain infections).
   The first clue to a relationship between the human leukocyte antigens
and  rheumatic  diseases came in 1973.  Scientists found an overwhelming
association  of  one  HLA  marker  known as HLA-B27 with AS and Reiter's
syndrome.   This  marker  is  found in only 8% of white people and 2% of
black  people,  but  in  95%  of  white  people with AS and 50% of black
people  with AS.  The HLA-B27 antigen is also found in a high proportion
of  symptom-free  relatives  of  these people.  Although the presence of
this  marker conveys a susceptibility to AS, fewer than one in five HLA-
B27 carriers actually develops the disease.
    Ankylosing  spondylitis affects about two in one thousand white men.
It  was  previously  thought to be very rare in women, but today doctors
and  scientists know that AS may occur in a mild form in a larger number
of women.
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                             CHAPTER FIFTEEN

                         ANKYLOSING SPONDYLITIS

POSSIBLE CAUSES

   Although  the  cause  of  spondylitis  is  unknown,  scientists  have
discovered  a  stong  genetic,  or  family,  link.  Almost all Caucasian
people with spondylitis have the genetic marker known as HLA-B27.  Some-
one  who  has  this  genetic marker will not necessarily develop AS, but
people  who do have it are more likely to develop the disease than those
who do not.
   Many  scientists  believe   that AS results from a combination of the
HLA-B27  marker  and  a  trigger  of some sort, most likely some kind of
infection.  The trigger may set off a reaction by the immune system that
becomes abnormal and leads to the damaging inflammation of AS.
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                         UNDERSTANDING ARTHRITIS
                               WHAT IT IS
                             HOW TO TREAT IT
                           HOW TO COPE WITH IT

                      THE ARTHRITIS FOUNDATION

                         Charles Scribner's Sons
                      Macmillan Publishing Company
                           New York, NY  10022