A2CPS Completes Recruitment
As of January 2026, the NIH Common Fund Acute to Chronic Pain Signatures (A2CPS) Consortium successfully completed recruitment of participants into their pain study, with a final tally of 2,285 participants. The A2CPS study is a major NIH-funded research initiative that aims to identify markers to predict whether someone is more or less likely to develop chronic pain after surgery.
Nearly 1 in 5 people worldwide suffer from chronic pain. For most people, acute pain – such as from an injury or a surgery – resolves once the injury heals. For others, this short-term pain can linger, and can last for years or even a lifetime. The A2CPS Consortium is looking for differences between people who transition from acute to chronic pain after surgery and those who do not. Identifying signatures that predict this transition could accelerate therapy development and inform strategies for pain prevention.
The Consortium recruited participants who underwent a total knee replacement or thoracic surgery. Researchers are collecting data from blood samples, brain imaging, functional testing, and patient-reported outcomes before and up to 12 months following surgery.
The A2CPS Consortium thanks the 2,285 participants who have generously donated their time, energy, and blood samples to this study. The team has also performed over 3,000 brain imaging sessions as part of this effort, ranking it the ninth largest brain-imaging study to date and the largest ever for the study of pain. The findings will help researchers better understand the complex biological processes underlying chronic pain, which may lead to better, more individualized treatments for patients.
A2CPS Featured in PAIN’s 50th Anniversary Issue
The A2CPS program was highlighted in the journal PAIN as part of their 50th anniversary special issue highlighting groundbreaking work shaping the future of pain science.
The A2CPS article showcases how the program is transforming the way researchers study chronic pain and charting new territory in understanding how acute pain becomes chronic. The article highlights how A2CPS represents a new model for collaborative, data-driven pain research and one that brings the field closer to personalized, predictive treatments for the millions affected by chronic pain.
Reference: Wager, T.D., Sutherland, S.P., Lindquist, M.A., Sluka, K.A, The A2CPS Consortium. Accelerating discovery in pain science: the Acute to Chronic Pain Signatures program. PAIN. 2025 November 1;166(11S):S95-S98. doi: 10.1097/j.pain.0000000000003674.
