Report aims to help distinguish aHUS disease vs. HELLP syndrome
Researchers highlight 4 criteria that may help in making correct diagnosis
The pregnancy-related complication HELLP syndrome — fully known as hemolysis, elevated liver enzymes, and low platelets syndrome, which causes high blood pressure and organ damage — is sometimes confused with atypical hemolytic uremic syndrome, or aHUS, a rare disease in which kidney dysfunction persists for a long time, especially when the complication occurs before or after a woman gives birth.
In the case of a young woman in India who had just had a baby and was initially believed to have aHUS, a team of doctors eventually ruled out the disease and reached a diagnosis of HELLP syndrome based on several key findings. Among them were the patient’s amount of urine output, a history of another pregnancy-related condition called preeclampsia, and certain abnormalities in the liver and kidneys that are typically seen in HELLP syndrome.
According to the team, aiding in their correct identification of the woman’s condition were “several features [that] favored the diagnosis of postpartum HELLP.”
Now, in correspondence with the Indian Journal of Gastroenterology, the researchers cited four criteria for “differentiating postpartum HELLP syndrome from aHUS in cases of prolonged acute kidney injury.”
Their case was “a diagnostic challenge,” according to the researchers, who described it in an article titled “Postpartum thrombotic microangiopathy with elevated liver enzymes: Distinguishing postpartum HELLP syndrome from atypical hemolytic uremic syndrome.”
Clinicians initially suspected aHUS disease, not HELLP in new mother
The researchers noted that, after childbirth, symptoms of aHUS and HELLP syndrome can look similar because both can cause clots to form in small blood vessels, leading to organ damage. However, kidney problems that persist after delivery are more suggestive of aHUS rather than HELLP, the team noted.
In HELLP syndrome, “symptoms can start from a few hours to seven days post-delivery, most often within 48 hours,” the researchers wrote. “These patients are at a higher risk for [acute kidney injury],” a sudden decrease in kidney function that usually develops within a few days and is often marked by a reduction in urine output.
Here, the team detailed the case of a 25-year-old woman who had mild preeclampsia toward the end of her pregnancy, with high blood pressure and proteins in the urine, but no severe symptoms. Three days after delivery, she developed abdominal pain and vomiting. Her blood pressure, meanwhile, had returned to normal.
Ultrasound imaging revealed hypoechoic lesions in the liver, which appear darker than the surrounding tissue. “Although a rare finding,” these hypoechoic lesions are indicative of postpartum HELLP syndrome, the team noted.
Blood tests revealed signs of thrombotic microangiopathy, with low numbers of red blood cells and platelets. There were also schistocytes, or fragmented red blood cells, and reticulocytes — young red blood cells — suggesting the body was trying to replenish the red blood cells that had been lost. Liver enzyme levels were high, as were markers of kidney dysfunction.
Initially suspecting aHUS due to persistent [acute kidney injury], we ultimately diagnosed postpartum HELLP syndrome.
Three days later, the woman had developed oliguria, marked by very little urine output, and needed hemodialysis, a type of treatment used to filter out waste and excess fluids from the blood when the kidneys can no longer do so. Hemodialysis was done the following day. A kidney biopsy then revealed acute tubular necrosis, which occurs when the cells that make up the tubes that filter out waste in the kidneys die.
Kidney function gradually improved and she was taken off hemodialysis. The woman was discharged about three weeks after giving birth and fully recovered later.
“Initially suspecting aHUS due to persistent [acute kidney injury], we ultimately diagnosed postpartum HELLP syndrome,” the researchers wrote, noting those four distinguishing features.
These included the fact that signs of kidney damage first appeared without a reduction in urine output, unlike aHUS, which usually causes no urine to be produced. A kidney biopsy also showed signs of acute tubular necrosis, which is common in HELLP syndrome. Hypoechoic lesions in the liver also supported that diagnosis, as did the woman’s history of preeclampsia during pregnancy.
“Since aHUS is a clinical diagnosis of exclusion, genetic testing for aHUS was not pursued based on the biopsy findings and complete renal recovery,” the researchers wrote.
The team noted their criteria in the correspondence.
“In summary, postpartum HELLP syndrome is more likely than aHUS if the patient is nonoliguric, has a history of preeclampsia, shows [acute tubular necrosis] on biopsy and exhibits liver ultrasound findings of hypoechoic lesions,” they wrote.
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