Correlation of platelet count changes with liver cell destruction in HELLP syndrome

HELLP syndrome is defined as a subset of preeclampsia involving a combination of hemolysis, low platelets affecting the circulatory system, and elevated liver enzymes, reflecting liver cell destruction. Our objective was to assess the correlation between the platelet count changes and liver cell destruction as indicated by aspartate aminotransferase (AST) levels.

We reviewed the records of 15 preeclamptic patients who developed HELLP syndrome as defined by 1) hemolysis, 2) elevated liver enzymes with an AST greater than 70 U/L (>2 SD above mean), and 3) low platelets (<100x10(9)/L). In these patients, both platelet counts and AST were assessed every 4-6 hr before and after delivery until recovery. At least eight laboratory assessments were done on each patient and were available for review. In each patient, the correlation between platelet count and AST levels was done using the Spearman rank order correlation coefficient.

A negative correlation was found between platelet count and AST levels. A correlation coefficient of greater than 0.8 occurred in 53% of cases. The correlation coefficient ranged from 0.1 to 0.93. In all cases, improvement of liver cell dysfunction occurred within 4 hr of recovery of platelet count. At 72 hr postpartum, 73% of the platelet counts had not recovered to >150x10(9)/L, and 66% of patients with abnormally elevated AST levels had not returned to <35 U/L.

Liver dysfunction and platelet count are poorly correlated in individual cases. This lack of correlation is evident both during decline and recovery of the platelet counts. Changes in platelet count cannot be used as a proxy for liver dysfunction in severe preeclampsia with HELLP syndrome.