HELLP Syndrome - Diagnosis and Classification

Diagnosis and Classification

HELLP syndrome can be difficult to diagnose due to the variability of symptoms among patients (frequently patients have no symptoms other than general abdominal pain), and early diagnosis is key in reducing morbidity. If not treated in a timely manner, a mother can become critically ill or die due to liver rupture/hemorrhage or cerebral edema.

In a patient with possible HELLP syndrome, a batch of blood tests is performed: a full blood count, a coagulation panel, liver enzymes, electrolytes, and renal function studies. Often, fibrin degradation product (FDP) levels are determined, which can be elevated. Lactate dehydrogenase is a marker of hemolysis and is elevated (> 600 U/liter). Proteinuria is present but can be mild.

In one 1995 study, a positive D-dimer test in the presence of preeclampsia was reported to be predictive of patients who will develop HELLP syndrome.

The diagnostic criteria for and subtypes of HELLP vary across studies, which "makes comparison of published data difficult." The classifications include:

• Criteria developed at the University of Tennessee:
  • HELLP is characterized by hemolysis on peripheral blood smear with serum lactate dehydrogenase >600 IU/L; serum aspartate aminotransferase >70 IU/L; and platelet count <100,000/μL.
  • Partial HELLP syndrome is characterized by 1-2 features of HELLP.
• Criteria developed at the University of Mississippi, as of 1999:
  • "The diagnosis of HELLP syndrome required the presence of thrombocytopenia (perinatal platelet nadir ≤150,000 cells/μL), evidence of hepatic dysfunction (increased aspartate aminotransferase level of ≥40 IU/L, increased alanine aminotransferase level of ≥40 IU/L, or both, with increased lactate dehydrogenase level of ≥600 IU/L), and evidence of hemolysis (increased LDH level, progressive anemia)...."
  • "Class 1 HELLP syndrome featured severe thrombocytopenia with a platelet nadir of ≤50,000 cells/μL, class 2 HELLP syndrome featured moderate thrombocytopenia with a platelet nadir between >50,000 and ≤100,000 cells/μL, and class 3 HELLP syndrome featured mild thrombocytopenia with a platelet nadir between >100,000 and ≤150,000 cells/μL."
• Criteria developed at the University of Mississippi, as of 2006: "For a patient to merit a diagnosis of HELLP syndrome, class 1 requires severe thrombocytopenia (platelets ≤50,000/μL), evidence of hepatic dysfunction (AST and/or ALT ≥70 IU/L), and evidence suggestive of hemolysis (total serum LDH ≥600 IU/L); class 2 requires similar criteria except thrombocytopenia is moderate (>50,000 to ≤100,000/μL); and class 3 includes patients with mild thrombocytopenia (platelets >100,000 but ≤150,000/μL), mild hepatic dysfunction (AST and/or ALT ≥40 IU/L), and hemolysis (total serum LDH ≥600 IU/L)."