Delay in treatment increases the risk of adverse
outcome, therefore prompt diagnosis is very important.
Diagnosis is made on the basis of clinical
symptoms and laboratory tests.
Blood test abnormalities, which
are necessary to establish the diagnosis of TTP, are:
- Low level of circulating
platelets
-
Hemolytic anemia
caused by fragmentation of red blood cells
It is important to distinguish
TTP from diseases with similar features as HUS,
HELLP and others (further details
on differential diagnosis can be found in the medical section
of this site).
Apart from the fore mentioned clinical symptoms,
at the moment there is no specific
diagnostic test for TTP. ADAMTS13 plasma levels and
presence of autoantibodies anti-ADAMTS13 are being evaluated
as possible diagnostic tests, but these do not fulfill the
required characteristics for a reliable diagnostic test (there
are TTP patients with normal values).