# Apolipoprotein A1: A potential biomarker in the secretome of euploid and aneuploid human embryos

## TL;DR

This study explores Apolipoprotein A1 as a potential biomarker to differentiate between healthy and chromosomally abnormal human embryos.

## Contribution

The study identifies Apolipoprotein A1 as a novel secreted biomarker for distinguishing euploid and aneuploid embryos.

## Key findings

- Apolipoprotein A1 levels in euploid cleavage-arrested embryos were significantly lower than the control group.
- Apolipoprotein A1 levels increased significantly in euploid and aneuploid embryos compared to the control group.
- Euploid early blastocysts had higher Apolipoprotein A1 levels than hatching blastocysts and aneuploid embryos.

## Abstract

Morphologic assessment of an embryo is a valuable indicator for determining
embryo health; however, it does not provide information on the chromosomal
status of an embryo. Therefore, this study aimed to investigate the levels
of Apolipoprotein A1 secreted by day-5 embryos in the spent media of euploid
and aneuploid human embryos.

This study utilized 131 spent culture media samples from 22 infertile couples
who were referred to the fertility clinic of Royan Institute. Following
ovulation induction, retrieved oocytes were fertilized by intracytoplasmic
sperm injection. For pre-implantation genetic diagnosis, embryos were frozen
and thawed on days 2 to 3 and a single blastomere was isolated from each
embryo for the assessment of chromosomal abnormalities by fluorescence
in situ hybridization. Five days after fertilization,
the levels of Apolipoprotein A1 were determined in the spent media of normal
embryos, aneuploid embryos (with chromosome abnormalities), and the control
group (medium without any embryos) using enzyme-linked immunosorbent
assay.

The Apolipoprotein A1 levels in the secretome of euploid cleavage-arrested
embryos were significantly lower than those in the control group
(p<0.04). However, Apolipoprotein A1 levels
increased significantly in groups of euploid blastocysts, aneuploid
cleavage-arrested embryos, aneuploid morulae, and aneuploid blastocysts
compared to the control group (p<0.04). Furthermore, the
Apolipoprotein A1 levels in the spent media of euploid early blastocysts
were significantly higher compared to euploid hatching blastocysts and
aneuploid blastocysts in the early, mid, and late stages
(p<0.03).

This study highlights the significant potential of Apolipoprotein A1 as a
developmental bi-omarker to distinguish between euploid and aneuploid
embryos.