Sialyl Tn and Zinc coproporphyrin1 as potential serum markers of amniotic fluid embolism

Abstract

Serological diagnosis of patients with amniotic fluid embolism (AFE), based on the detection of Sialyl-Tn (STN) and Zinc coproporphyrin1 (Zn-CP1), is a unique and original method used in Japan. Maternal serum (MS) levels of STN and Zn-CP1 have been measured at the Hamamatsu University School of Medicine in the Department of Obstetrics and Gynecology as part of a project of the Japan Association of Obstetricians and Gynecologists for diagnosing AFE. Serum data from 201 individuals enrolled from 1992 to 2006 were used in this study. Seventy-four of the 201 cases did not fit the definition for differential diagnoses for patients presenting with possible AFE (controls). The purpose of this study was to evaluate the usefulness of STN and Zn-CP1 as serum markers for diagnosing AFE. The number of samples with concentrations greater than the upper reference limit for MS STN (>47U/ml) and MS Zn-CP1 (>1.6 pmol/ml) was found to be significantly higher in AFE patients than in controls by the Chi-square test (STN: p=0.00003; Zn-CP1: p=0.00953). Serum STN levels in AFE patients were higher compared with those in controls (p=0.0011), unlike Zn-CP1 levels (p=0.0994). The sensitivity and specificity of MS STN and MS Zn-CP1 levels were 25.8% and 97.3% and 45.9% and 73.0%, respectively. This study demonstrated that STN and Zn-CP1 levels are potential markers for the diagnosis of AFE. The diagnosis of AFE should be that of exclusion and strongly suspected by clinical manifestations; it should not be solely based on serological STN and Zn-CP1 values. [Adv Obstet Gynecol, 63(4) : 483-487, 2011 (H23.11)]