CPPD

Working group OMERACT > CPPD

MENTOR: Annamaria Iagnocco

Convenors: Georgios Filippou and Nemanja Damjanov

web page referent: Georgios Filippou

Target domain:

Objective of the subgroups work: 

The subtask force was founded in 2014 with the objective to validate US for use in Calcium Pyrophosphate deposition Disease (CPPD) for diagnosis, assessment of inflammation, assessment of structural damage and extension of CPP deposition in tissues.

Description of possible contribution of the subgroup work for OMERACT :

The OMERACT CPPD working group has been formed only recently (spring 2019) and in this first phase is concentrating the efforts on the definition of the domains of the disease. The chairs of the two groups are in contact and collaborating in these first steps of the working group. The US subgroup will contribute in the future steps of the process, accordingly with the needs of the CPPD working group.  

Short description of the previous work (including publications)

- Creation of definitions for US CPPD identification,

- Investigation of reliability

- Investigation of validity

 
The new OMERACT definitions demonstrated to be reliable at the level of wrists and knees. The definitions have been used also by external researchers that confirmed the OMERACT group data regarding the reliability. US demonstrated also to be a valid tool for CPPD identification.

·         1. Filippou G, Adinolfi A, Iagnocco A, et al. Ultrasound in the diagnosis of calcium pyrophosphate dihydrate deposition disease. A systematic literature review and a meta-analysis. Osteoarthritis Cartilage. 2016;24(6):973‐981. doi: 10.1016/j.joca.2016.01.136  

·         2. Filippou G, Scirè CA, Damjanov N, et al. Definition and Reliability Assessment of Elementary Ultrasonographic Findings in Calcium Pyrophosphate Deposition Disease: A Study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force. J Rheumatol. 2017;44(11):1744‐1749. doi:10.3899/jrheum.1610572.      

·         3. Filippou G, Scirè CA, Adinolfi A, et al. Identification of calcium pyrophosphate deposition disease (CPPD) by ultrasound: reliability of the OMERACT definitions in an extended set of joints-an international multiobserver study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force. Ann Rheum Dis. 2018;77(8):1194‐1199. doi:10.1136/annrheumdis-2017-212542

Reporting back of work done since previous F2F meeting (ACR, EULAR or OMERACT)

The validation study for truth and discrimination has been submitted for publication. 69 patients have been included from 12 centres and the results of the study have been presented at the EULAR 2020 online OMERACT meeting. Briefly, US demonstrated to be able to distinguish CPP deposition (gold standard histology) with an accuracy rate of 82%.

 Next steps and discussion points

Due to COVID pandemic the work of the group was delayed. The next step will aim to the creation of a grading system for CPPD extension in order to validate US also for monitoring the evolution of CPPD over time. The protocol will be discussed starting form the EULAR 2020 OMERACT meeting and will be ready by the end of Q3 2020. A delphi exercise will be launched by Q4 2020 – Q1 2021.