The 2023 ACR/EULAR classification criteria for calcium pyrophosphate deposition disease

Abstract

ObjectiveCalcium pyrophosphate deposition (CPPD) disease is prevalent and has diverse presentations, but there are no validated classification criteria for this symptomatic arthritis. The American College of Rheumatology (ACR) and EULAR have developed the first-ever validated classification criteria for symptomatic CPPD disease.MethodsSupported by the ACR and EULAR, a multinational group of investigators followed established methodology to develop these disease classification criteria. The group generated lists of candidate items and refined their definitions, collected de-identified patient profiles, evaluated strengths of associations between candidate items and CPPD disease, developed a classification criteria framework, and used multi-criterion decision analysis to define criteria weights and a classification threshold score. The criteria were validated in an independent cohort.ResultsAmong patients with joint pain, swelling, or tenderness (entry criterion) whose symptoms are not fully explained by an alternative disease (exclusion criterion), the presence of crowned dens syndrome or calcium pyrophosphate crystals in synovial fluid are sufficient to classify a patient as having CPPD disease. In the absence of these findings, a score>56 points using weighted criteria, comprising clinical features, associated metabolic disorders, and results of laboratory and imaging investigations, can be used to classify as CPPD disease. These criteria had a sensitivity of 92.2% and specificity of 87.9% in the derivation cohort (190 CPPD cases, 148 mimickers), whereas sensitivity was 99.2% and specificity was 92.5% in the validation cohort (251 CPPD cases, 162 mimickers).ConclusionThe 2023 ACR/EULAR CPPD disease classification criteria have excellent performance characteristics and will facilitate research in this field.

First classification criteria for diseases caused by calcium pyrophosphate deposition (CPPD)—Translation, explanation and assessment

“…Die detaillierte Beschreibung der Entwicklung der Klassifikationskriterien für die CPPD-Erkrankung ist der Originalpublikation zu entnehmen (Abb. 5 ; [ 16 , 17 ]). Diese gliederte sich in die Erstellung von Variablenlisten, die Identifikation von Patientenprofilen und die Untersuchung der Assoziationen zwischen den Variablen und der CPPD-Erkrankung.…”

“…Liegen diese Befunde nicht vor, kann eine Punktzahl von mehr als 56 Punkten anhand gewichteter Kriterien, die sich aus klinischen Merkmalen, begleitenden Stoffwechselstörungen und Ergebnissen von Labor- und Bildgebungsuntersuchungen zusammensetzen, zur Klassifikation als CPPD-Erkrankung herangezogen werden. Diese Kriterien hatten eine Sensitivität von 92,2 % und eine Spezifität von 87,9 % in der Entwicklungskohorte (190 CPPD-Fälle, 148 CPPD „mimics“), während die Sensitivität 99,2 % und die Spezifität 92,5 % in der Validierungskohorte (251 CPPD-Fälle, 162 CPPD „mimics“) betrug ([ 17 ]; s. auch Abb. 6 ).…”

“…1 ) zu entwickeln, die die Erforschung der CPPD-Krankheit erleichtern sollen, wurde mit Unterstützung des American College of Rheumatology (ACR) und der European Alliance of Associations for Rheumatology (EULAR) eine internationale Arbeitsgruppe einberufen. Das Ziel war die Entwicklung von Klassifikationskriterien, die es den Forschern ermöglicht, Menschen mit CPPD-Erkrankungen für die Teilnahme an klinischen und Beobachtungsstudien sicherer zu identifizieren [ 16 , 17 ].…”

Describing calcium pyrophosphate deposition: undoing the tower of Babel!

“…Finally, the 2023 EULAR/ACR classification criteria for CPPD disease, categorized CPPD patients in three clinical phenotypes based on the number and course of clinical symptoms. These phenotypes emerged by the preliminary collection of a large number of clinical cases and after the statistical analysis was performed, the phenotype ‘more than one attacks of acute arthritis’ appeared to be the most specific one for CPPD while ‘persistent arthritis’ the least as deduced from their weight in the classification items [8 ▪▪ ].…”

“…However, should be kept in mind that a significant limitation in describing CPPD by radiography lies in its two-dimensional nature, where the superimposition of different structures, especially in case of advance osteoarthritis, can affect the recognition of CPP deposits [35]. Indeed, recent studies have confirmed that the sensitivity of radiography for CPPD identification is far from being optimal, but thanks to its high specificity, detecting CPPD on radiography is considered at the same level as ultrasound and CT in the recently published classification criteria for CPPD disease [8 ▪▪ ,9 ▪▪ ]. The development of a radiographic scoring system for CPPD extent in the near future, could contribute further to enhancing the role of radiography in characterization of CPPD.…”