Woman with twin pregnancy found to have aHUS after delivery: Case study
Rare case highlights need to promptly ID, treat disorder
A woman in her mid-30s with a twin pregnancy was diagnosed with atypical hemolytic uremic syndrome (aHUS) after she experienced complications following delivery by cesarean section.
Two healthy girls were born, and the mother’s condition improved following treatment.
But researchers noted that “this report underlines how crucial it is … to promptly identify [aHUS], since early initiation of eculizumab, together with supportive therapy, has a direct effect on patient outcome.”
Although rare, pregnancy-related aHUS is associated with high maternal morbidity and mortality, and therefore early detection and treatment are critical, the team noted.
The case was described in the study, “A case report of an atypical haemolytic uremic syndrome in pregnancy: something wicked this way comes,” published in the journal BMC Anesthesiology.
Woman with twin pregnancy had anemia, high blood pressure
aHUS is caused by the abnormal activity of the complement cascade — a group of immune proteins that trigger powerful inflammation and blood clotting when activated.
Pregnancy and its complications may increase the risk of aHUS in patients predisposed to complement dysregulation. Indeed, estimates indicate that 10%-20% of all aHUS cases are pregnancy-associated.
Now, researchers in Italy described the case of a 35-year-old woman pregnant with twins, who underwent a cesarean section at 36 weeks, or about eight months into her pregnancy. Surgery occurred without complications, though a tendency toward high blood pressure was detected.
About 1.5 hours after the end of the cesarean section, the patient started experiencing fatigue and shortness of breath. She had an acute hemorrhage (bleeding) due to a retained placenta, and had to be rushed to the operating room for exploratory surgery.
Laboratory tests performed before and after surgery had confirmed only a reduction in hemoglobin levels, consistent with anemia. Hemoglobin is the protein in red blood cells responsible for oxygen transport.
Due to her pre-existing anemia and high blood loss during surgery, the woman was given three units of red blood cells along with other therapies to control bleeding.
She also was treated with oxytocin to stimulate the contraction of uterine muscles to clamp placental blood vessels. Misoprostol and a specific device placed in the uterus also were used to stop the hemorrhage.
After surgery, laboratory tests revealed the presence of anemia, low platelet counts, low levels of fibrinogen — a protein that plays a key role in blood clotting — and acute kidney injury.
One additional red blood cell unit and fibrinogen were given. After that, she developed respiratory failure and had to be transferred to the intensive care unit (ICU) for ventilation and oxygen therapy.
The patient appeared alert and oriented in the ICU, despite having high blood pressure, rapid breathing, and a rapid heart rate. Chest X-rays and ultrasounds confirmed the accumulation of fluids in her lungs. She was treated for high blood pressure and fluid accumulation.
Further laboratory tests revealed an increase in the levels of lactate dehydrogenase, a marker of tissue damage, and confirmed the presence of anemia, low platelet counts, and acute kidney injury. At this time, she was diagnosed with aHUS and started on treatment with Soliris (eculizumab), an antibody-based therapy designed to block complement activation.
Her respiratory condition gradually improved over the next days. After 36 hours, oxygen therapy was sufficient. Despite treatment, however, her blood pressure remained high and she continued showing signs of severe anemia that required her to receive additional blood transfusions. After five days, she was discharged from the ICU to the internal medicine department.
Her condition progressively improved. A genetic analysis failed to identify aHUS-related mutations. She received two additional doses of Soliris and was discharged from the hospital 16 days after being admitted.
“We recommend considering aHUS among possible competing [diagnoses] in patients with risk factors, who rapidly develop [anemia, low platelet levels] and severe [kidney] failure in the immediate postpartum period,” the researchers wrote.
Eculizumab has recently been recognized as a good therapeutic strategy for aHUS, but clinicians should have a high index of suspicion, as a prompt diagnosis and a target treatment may enable a full recovery.
The patient described in this report had major risk factors for aHUS, including a twin pregnancy, high blood pressure, placenta retention, and hemorrhagic shock.
It has been proposed that the occurrence of aHUS after newborn delivery may be related to the placenta acting as a protective factor against complement activation. Once the placenta is removed, protective mechanisms holding complement activation in check are no longer active, which may lead to the onset of aHUS.
“Eculizumab has recently been recognized as a good therapeutic strategy for aHUS, but clinicians should have a high index of suspicion, as a prompt diagnosis and a target treatment may enable a full recovery,” the team wrote.