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If you think you have Hughes Syndrome, click here
to find out about the blood tests and getting a diagnosis -
remember, you don't need to suffer from all the symptoms
listed to have Hughes Syndrome.
Making the diagnosis
The diagnosis depends on the history, the examination, and special
tests. The doctor will ask about clotting problems in the past
(any history of clots in the leg or lung), previous strokes
or heart attacks (and whether they occurred at young ages),
less specific clues such as headaches, migraine, memory loss,
and confusion. Women will be questioned about past pregnancies,
and whether there were any complications. They will be asked
specifically about any miscarriages, and at what stage of pregnancy
they occurred.
A lacy, net-like, red rash known as 'livedo reticularis' (some
patients call this corn beef skin!), is often found in antiphospholipid
syndrome, particularly over the wrists and knees.
A simple blood test can detect the 'antiphospholipid antibodies'.
Other blood tests can check for underlying conditions, such
as lupus. The doctor may also assess other risk factors for
thrombosis - by measuring the patients blood pressure to rule
out hypertension, checking their glucose levels to rule out
diabetes and measuring cholesterol levels.
The blood tests
 The
blood tests for Hughes Syndrome have complicated names but are
essentially simple and universally available through your doctor/GP.
There are two tests – anticardiolipin antibodies
and the confusingly named lupus anticoagulant.*
| Screening
test for Hughes Syndrome |
| Anticardiolipin
Antibodies (aCL) |
YES |
sometimes
referred to as Antiphospholipid
positive
in 80% of cases
higher levels
= higher risk of thrombosis |
| Lupus Anticoagulant
(LA) |
YES
|
Positive
in 30-40% of cases
Cannot
be used if patient is on warfarin |
*
The confusing term ‘lupus anticoagulant’ should
be done away with. It is NOT a test for
Lupus and is NOT an anticoagulant. But
it is a historical term, and so far has stuck. Confusion
is added to by the variety of clotting tests used in different
laboratories with abbreviations including KCT, KCCT, DRVVT
and so on. A topic best left to the haematologists.
Of these two tests,
the first is far more important and more frequently positive
– but because nature can be awkward, some patients have
only one or other test positive – hence the need to
test for both. Having said this, we do see some patients who
appear to have Hughes Syndrome in whom both tests are negative.
It is usually advisable
to repeat the blood tests on more than one occasion –
especially if the results are ‘borderline’ or
‘doubtful’. One positive test for antiphospholipid
antibodies does not mean that a person has Hughes Syndrome.
For this reason, the test should be repeated after 6-8 weeks.
A positive test on two occasions is much more important for
doctors making the diagnosis than a test that is only positive
once.
Tests that are
only just positive and that are present on only one occasion
may not be significant. This is because harmless antiphospholipid
antibodies can be detected in the blood for brief periods,
occasionally in association with a wide variety of conditions,
including infections and certain drugs (e.g. antibiotics and
certain blood pressure pills).
In making the diagnosis,
the patients history is often more important than the actual
test results – for example, a 40 year old with a DVT
and lung clot may not link it with the teenage migraine she
suffered, or the two previous miscarriages. These
points may seem pedantic but Hughes Syndrome is a diagnosis,
which if made early, can totally turn around the prognosis from
a potentially life threatening disease to a relatively normal
life.
Sapporo criteria
In 1998, a
group of colleagues meeting at an international consensus conference
in Sapporo, Japan, agreed on a list of "classification
criteria". These were described not primarily for diagnosis,
but more for international agreement in treatment trials and
other research collaboration. However, although the criteria
are meant for research workers and doctors, and NOT primarily
for the general public, they are very important guidelines and
therefore given in full below:
| Clinical
criteria |
| 1.
Vascular thrombosis |
• One or more clinical episodes of arterial,
venous, or small vessel thrombosis, in any tissue or
organ. Thrombosis must be confirmed by imaging or Doppler
studies or histopathology, with the exception of superficial
venous thrombosis. For histopathologic confirmation,
thrombosis should be present without significant evidence
of inflammation in the vessel wall.
|
| 2. Pregnancy
morbidity |
•
One or more unexplained deaths of a morphologically
normal fetus at or beyond the 10th weeks of gestation,
with normal fetal morphology documented by ultrasound
or by direct examination of the fetus, or
• One
or more premature births of a morphologically normal
neonate at or before the 34th weeks of gestation because
of severe pre-eclampsia, or severe placental insufficiency
or
• Three
more unexplained consecutive spontaneous abortions before
the 10th week of gestation, with maternal anatomic,
or hormonal abnormalities and paternal and maternal
chromosomal causes excluded. |
| Laboratory
criteria |
| 1. Anticardiolipin
antibody |
Anticardiolipin
antibody of IgG and/or IgM isotype in blood, present
in medium or high titre, on two or more occasions, at
least 6 weeks apart, measured by a standard enzyme linked
immunosorbent assay for ß2-glycoprotein 1-dependent
anticardiolipin antibodies*.
* Most laboratories
only measure the anticardiolipin antibody. Although
the 'extra step' of ß2-glycoprotein 1 is correct
in scientific terms it is time consuming and only positive
in a minority of patients. Hence it is not generally
included in routine testing.
|
| 2. Lupus anticoagulant |
Lupus anticoagulant
present in plasma on two or more occasions at least 6
weeks apart, detected according to the guidelines of the
International Society on Thrombosis and Hemostasis. |
Definite Hughes
Syndrome (APS) is considered to be present if at least one
of the clinical and one of the laboratory criteria are met.
* Most laboratories
only measure the anticardiolipin antibody. Although the 'extra
step' of ß2-glycoprotein 1 is correct in scientific
terms it is time consuming and only positive in a minority
of patients. Hence it is not generally included in routine
testing.
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