Artwork by Kathleen Sluka

For most people, pain goes away when an injury heals. But for some people, pain after surgery can linger, and can last for years or even a lifetime. The Acute to Chronic Pain Signatures (A2CPS) project is a bold research initiative - the largest and most comprehensive of its kind - being carried out by a nation-wide consortium of researchers. The findings will help researchers to develop better, more individualized treatments for patients and to better understand the complex biological processes underlying chronic pain.

About A2CPS


A2CPS will collect questionnaires, blood samples and brain imaging from 2,800 participants before and for up to 12 months after having total knee replacement or thoracic surgery.


Many diseases can be diagnosed, tracked and predicted with biological markers, or biomarkers, but none are yet known for chronic pain. The major aim of A2CPS is to find biomarkers or bio-signatures of the transition to chronic pain.


The A2CPS consortium is organized into four main hubs, with over 100 investigators and staff around the country. Our researchers span a wide range of expertise, from basic scientists to clinicians to data management experts.


In addition to biological specimens, A2CPS also collects different types of data from our participants, including patient-reported outcomes (PROs) and quantitative sensory testing (QST), among others.


The term “omics” refers to the collection of information about the molecules found in our blood, which can tell us about the activity of genes, proteins, lipids and metabolites in our cells and tissues.

Brain Imaging

Previous studies have identified “signatures” of brain activity that reflect a painful experience, and others that predicted who was more likely to develop chronic pain. A2CPS will include brain-imaging data in our search for biosignatures of chronic pain.


Optimization of Imputation Strategies for High-Resolution Gas Chromatography–Mass Spectrometry (HR GC–MS) Metabolomics Data

Published May 2022

A major aim of A2CPS is to identify biomarkers and biosignatures of the transition to chronic pain. That includes metabolomics, in which metabolites are detected in the blood using technology called gas chromotography-coupled mass spectroscopy (GC-MS). In a new paper published in the journal Metabolites, A2CPS investigator Michael Olivier and colleagues find new ways to optimize data handling from their GC-MS experiments. Congrats to the metabolomics team!

A2CPS Consortium Meeting: March 23rd, 2022

Published March 2022

Join us Mar 23 at 2ET as our entire A2CPS consortium gathers onscreen. Learn more about this groundbreaking research effort - plus invited talks from Yarimar Carrasquillo, Ted Price, and Vivianne Tawfik.

Register Now

Acute to Chronic Pain Signatures Investigator Awarded NIH Funding

Published November 2021

Congratulations to Acute to Chronic Pain Signatures (A2CPS) Consortium member Giovanni Berardi, DPT, PhD, who was recently awarded funding from the National Institutes of Health’s HEAL (Helping to End Addiction Long-termSM) Initiative. The NIH HEAL InitiativeSM is aimed at improving prevention and treatment strategies for both opioid abuse and chronic pain.

New Multisite Clinical Center

Published December 2020

A group from the University of Michigan has been chosen to lead the second A2CPS Multisite Clinical Center. They will study 1,800 individuals scheduled for thoracic surgery.

Welcome to the A2CPS team!