A
blood test could aid in the diagnosis of TTP/AHUS in pregnant women, according
to a new study.
A
small study indicated that a blood test could help doctors distinguish between
HELLP syndrome, a pregnancy complication, and thrombotic thrombocytopenic
purpura (TTP) and atypical hemolytic uremic syndrome (AHUS).
The
test examines the ratio of two proteins that indicate tissue damage: lactate
dehydrogenase (LDH) and aspartate aminotransferase (AST). The LDH:AST ratio was
almost 30 times greater in women with TTP/aHUS than in those with HELLP
syndrome, a pregnancy complication that can cause kidney or liver damage,
according to the researchers.
According
to the researchers, these data support the use of "the LDH:AST ratio as a
viable screening tool for doctors to identify TTP/aHUS from HELLP
syndrome."
The
study was published in the International Journal of Gynecology and Obstetrics
and was titled "Maternal morbidity and mortality in pregnant/postpartum
women with suspected HELLP syndrome identifiable as probable thrombotic
thrombocytopenic purpura or atypical hemolytic uremic syndrome by high LDH to
AST ratio."
The
HELLP syndrome, which stands for hemolysis, high liver enzymes, and low
platelets, is a pregnancy condition that can cause kidney and liver damage. It
is characterised by the destruction of red blood cells (hemolysis), an increase
in liver enzymes, and a decrease in platelet counts. It usually occurs near the
end of pregnancy or shortly after childbirth.
Because
not all symptoms are visible and several other disorders have overlapping
symptoms, diagnosing the condition can be difficult. TTP and aHUS, for example,
are two illnesses in which blood clots form in small blood vessels. It's still
difficult for clinicians to tell the difference between TTP/aHUS and HELLP
syndrome.
The
researchers wrote, however, that "it is critical to facilitate correct and
prompt decisions for diagnosis and therapy of these disorders."
The
researchers expanded on prior findings that women with TTP have a high LDH: AST
ratio, which is always greater than 22:1. They now want to see if the LDH: AST
ratio can assist differentiate TTP/aHUS from HELLP syndrome.
The
study comprised 58 women who were pregnant or had recently given birth and had
been diagnosed with HELLP syndrome. Eight of them had TTP/aHUS, which was
defined by severe thrombocytopenia, or unusually low platelet counts, at the
time of admission. Their platelet counts were less than 20,000 per microliter
of blood in particular.
The
mothers were on average 26.4 years old, and their kids were born at 35.4 weeks
gestation.
TTP/aHUS
was diagnosed in six of the women before they went into delivery. One woman
survived plasma exchange treatment; the other two ladies died before plasma
exchange treatment could begin. Plasma exchange is a type of treatment in which
a patient's plasma — the clear liquid component of their blood — is replaced.
Three
to five days after giving birth, the other two women were diagnosed with
TTP/aHUS. They also exhibited significant thrombocytopenia and LDH levels that
were abnormally high. One of the women survived a plasma exchange, but the
other did not.
When
researchers computed the mean LDH:AST ratio based on LDH and AST levels, they
discovered that it was 32:1, much higher than the 22:1 ratio previously
reported. The 42 women with confirmed HELLP syndrome had a mean LDH: AST ratio
of 2:1. The ladies in this study were on average 29 years old, and their babies
were born at a gestational age of 34 weeks.
According
to the researchers, the lesson from the findings was clear: doctors should
compute the LDH: AST ratio in women with probable HELLP syndrome.
The
number of platelets and the activity of a protein called ADAMTS13, which is
used to distinguish TTP from aHUS, should also be measured, according to the
researchers.
"Implementation
of the suggested screening approach could certainly minimise the chance of
significant maternal morbidity and maternal death," they wrote, adding
that this step could "shorten the detection to treatment time."