Plasma Exchange, Soliris May Help Treat Pregnancy-related aHUS
Plasma exchange and treatment with Soliris (eculizumab) may be used successfully to treat pregnancy-related atypical hemolytic uremic syndrome (aHUS) complicated by kidney failure, a case report suggests.
The report, “Atypical hemolytic uremic syndrome: when pregnancy leads to lifelong dialysis: a case report and literature review,” was published in the journal Cardiovascular Endocrinology & Metabolism.
aHUS is a rare disease caused by the abnormal activation of the complement system — a set of more than 30 proteins that forms part of the body’s immune defenses.
While genetic mutations can predispose individuals toward developing aHUS, in almost all cases an additional trigger event, like an infection, is needed for the disease to develop.
Pregnancy can be a trigger for aHUS and cause the condition to worsen by promoting red blood cell destruction (hemolysis) and the formation of blood clots in small blood vessels, leading to organ damage — a condition known as thrombotic microangiopathy (TMA). Most commonly, this affects the kidneys, and can result in kidney failure.
In this report, clinicians at the Nassau University Medical Center in New York described the case of a 18-year-old African American woman with aHUS who was admitted to the ICU due to high blood pressure after missing her hemodialysis session. Her clinical history, besides kidney failure, also included epilepsy and high blood pressure.
She reported no symptoms at admission and a physical examination was uneventful.
The patient was immediately treated for high blood pressure, which normalized after a single dialysis session. She was discharged soon after, and continued to be managed at a local dialysis center.
A review of her medical history showed that her aHUS diagnosis followed complications with a prior pregnancy. Genetic factors might have also played a role, the authors noted.
She delivered a premature baby at 34 weeks of gestation by emergency cesarean section due to preeclampsia — a pregnancy complication characterized by high blood pressure and organ damage — and HELLP syndrome, a life-threatening pregnancy complication usually considered to be a variant of preeclampsia.
After giving birth, she was diagnosed with microangiopathic hemolytic anemia, a condition in which red blood cells are destroyed due to physical damage, and aHUS.
She declined plasma exchange therapy (plasmapheresis) and was discharged with pulse-dose steroids. Her creatinine levels remained high (2 mg/dL), a sign of kidney damage. Of note, plasma exchange involves replacing a person’s plasma — the non-cellular parts of blood.
Her family’s medical history was deemed informative, as her mother, who was also diagnosed with preeclampsia and HELLP syndrome during pregnancy, also required dialysis after giving birth.
About five weeks after her discharge, the patient had another episode of red blood cell destruction and TMA, which manifested as acute kidney failure with creatinine levels peaking at 18.85 mg/dL.
As a result of poor kidney function, toxic waste products accumulated in her blood, causing nausea and vomiting.
She was now started on plasma exchange therapy along with Soliris, an approved aHUS therapy by Alexion that works to prevent complement system overactivation.
She received a total of three blood transfusions to normalize her hemoglobin levels. (Hemoglobin is the protein in red blood cells that is responsible for oxygen transport.)
Further tests revealed she was positive for a type of self-reacting antibody, called antinuclear antigen or ANA.
Ultrasound analysis confirmed kidney disease, with no additional diseases identified. She continued treatment with Soliris along with biweekly hemodialysis sessions.
Overall, “this unique case demonstrates the importance of understanding thrombotic microangiopathies (TMA) as a diagnosis while also recognizing concomitant consequences during pregnancy,” the scientists wrote.
This is particularly relevant, they added, considering that “pregnancy-associated aHUS results in a poor prognosis, with irreversible renal failure if left untreated.”