Report from the EULAR ACR Scleroderma Classification Criteria Committee

Abstract

Classification criteria for SSc are being updated as previous ACR preliminary classification criteria did not include some lcSSc patients and early SSc.

Objectives. Items from two large European and NA surveys were reduced by experts using Delphi and nominal group techniques that resulted in 23 items. The face, discriminant and construct validity were studied using many databases in Europe and NA. Further item reduction occurred ranking 20 cases of SSc and mimickers by experts with variable probabilities of having SSc and weighing items relative to each other after agreeing on further item reduction using the 1000 minds exercise.

Results. In the Delphi exercise, skin thickening, SSc-specific autoantibodies, abnormal nailfold capillary pattern, RP and some organ involvement ranked highest. Compared with diseases that mimic SSc in multiple databases, SSc patients are more likely to have skin thickening (OR = 427), telangiectasias (OR = 91), RNA polymerase III (OR = 75), puffy fingers (OR = 35), finger flexion contractures (OR = 29), tendon/bursal friction rubs (OR = 27), topo I (OR = 25), RP (OR = 24), finger tip ulcers/pitting scars (OR = 19), anti-centromere (OR = 14), abnormal nailfold capillaries (OR = 10), GERD (OR = 8) and ANA, calcinosis, dysphagia, oesophageal dilation (all OR = 6), ILD/pulmonary fibrosis (OR = 5) and PM-Scl antibody (OR = 2). Low DL_CO and FVC and PAH had OR <2. Renal crisis and digital pulp loss/acro-osteolysis did not occur in SSc mimickers. The 1000 minds exercise had experts ranked 20 cases and eliminated some of the 23 items. A scoring system found variable weighting of several items.

Future direction. Thousand minds cases will be rescored by experts and then further item reduction will occur by consensus and statistical item reduction for redundant criteria, with validation in databases and prospectively collected patients with standardized case report forms at multiple sites of cases and mimickers.