Large-scale molecular endotype discovery in synovial fluid reveals osteoarthritis as a single biological continuum

T T. A. Perry Y Y. Deng P P. A. Hulley R R. A. Maciewicz J J. Mitchelmore S S. Larsson J J. Gogain S S. Brachat A A. Struglics C C. T. Appleton S S. Kluzek N N. K. Arden D D. Felson L L. Bondi M M. Kapoor L L. S. Lohmander T T. J. Welting D D. A. Walsh A A. M. Valdes L Luke Jostins-Dean F Fiona E. Watt B B. D. M. Tom T T. L. Vincent T Thomas A. Perry Y Yun Deng (Center for Computational Biology) P Philippa A. Hulley R Rose M. Maciewicz S Stefan Kluzek N Nigel K. Arden T Tonia L. Vincent V Vicky Batchelor J Jennifer Mackay-Alderson G Gretchen Brewer B Brian Marsden A Andrew J. Price M Megan Goff V Vinod Kumar J James Tey T Tamas Szommer J Joanna Mitchelmore S Sophie Brachat J Juerg Gasser L Lori Jennings S Staffan Larsson A André Struglics L L. Stefan Lohmander J Joe Gogain D Darryl Perry A Anna Mitchel E Ela Zepko C C. Thomas Appleton T Trevor B. Birmingham J J. Daniel Klapak D David Felson L Laura Bondi B Brian D. M. Tom M Mohit Kapoor R Rajiv Gandhi A Anthony Perruccio Y Y. Raja Rampersaud K Kim Perry T Tim J. Welting P Pieter Emans T Tim Boymans L Liesbeth Jutten M Marjolein Caron G Guus van den Akker D David A. Walsh A Ana M. Valdes M Michael Doherty V Vasileios Georgopoulos A Artemis Papadaki A Andrew Williams T Tim Hardingham S Sarah Kennedy J Jeymi Tambiah D Devis Galesso N Nicola Giordan W Waqar Ali

Abstract

Abstract Knee osteoarthritis affects 40% of people during their lifetime, significantly impacting societies worldwide. Its molecular pathogenesis remains poorly understood and variable clinical phenotypes suggest it may be more than one disease. We established S ynovial fluid T o detect E ndoty p es by U nbiased P roteomics in OA (STEpUP OA) to search for molecular endotypes in knee OA synovial fluid, and to reveal key pathobiological pathways across 1361 individuals with knee OA. Using unsupervised clustering, a single cluster representing a biological continuum is observed, primarily driven by “Epithelial Mesenchymal Transition”. Distinct molecular endotypes are not detected. “Angiogenesis”, “Complement” and “Coagulation” are enriched for after stratification by clinical phenotype (obesity status, biological sex). Complement and coagulation are associated with the inflammatory marker, C-reactive protein. Associations with patient-reported knee pain are weaker. These findings support knee OA as a biological continuum, identify common and phenotype-enriched targetable pathways, and a rationale for stratification in clinical trial design.

Article Details

Volume / Issue Vol. 17, Issue 1
Published June 02, 2026
ISSN 2041-1723
Publisher Nature Portfolio

Journal Info

Nature Communications

Nature Portfolio

ISSN: 2041-1723 Open Access Life Sciences

Authors (79)

T

T. A. Perry

Y

Y. Deng

P

P. A. Hulley

R

R. A. Maciewicz

J

J. Mitchelmore

S

S. Larsson

J

J. Gogain

S

S. Brachat

A

A. Struglics

C

C. T. Appleton

S

S. Kluzek

N

N. K. Arden

D

D. Felson

L

L. Bondi

M

M. Kapoor

L

L. S. Lohmander

T

T. J. Welting

D

D. A. Walsh

A

A. M. Valdes

L

Luke Jostins-Dean

F

Fiona E. Watt

B

B. D. M. Tom

T

T. L. Vincent

T

Thomas A. Perry

Y

Yun Deng

Center for Computational Biology

P

Philippa A. Hulley

R

Rose M. Maciewicz

S

Stefan Kluzek

N

Nigel K. Arden

T

Tonia L. Vincent

V

Vicky Batchelor

J

Jennifer Mackay-Alderson

G

Gretchen Brewer

B

Brian Marsden

A

Andrew J. Price

M

Megan Goff

V

Vinod Kumar

J

James Tey

T

Tamas Szommer

J

Joanna Mitchelmore

S

Sophie Brachat

J

Juerg Gasser

L

Lori Jennings

S

Staffan Larsson

A

André Struglics

L

L. Stefan Lohmander

J

Joe Gogain

D

Darryl Perry

A

Anna Mitchel

E

Ela Zepko

C

C. Thomas Appleton

T

Trevor B. Birmingham

J

J. Daniel Klapak

D

David Felson

L

Laura Bondi

B

Brian D. M. Tom

M

Mohit Kapoor

R

Rajiv Gandhi

A

Anthony Perruccio

Y

Y. Raja Rampersaud

K

Kim Perry

T

Tim J. Welting

P

Pieter Emans

T

Tim Boymans

L

Liesbeth Jutten

M

Marjolein Caron

G

Guus van den Akker

D

David A. Walsh

A

Ana M. Valdes

M

Michael Doherty

V

Vasileios Georgopoulos

A

Artemis Papadaki

A

Andrew Williams

T

Tim Hardingham

S

Sarah Kennedy

J

Jeymi Tambiah

D

Devis Galesso

N

Nicola Giordan

W

Waqar Ali