[SAT0421] PRINCE: PROGNOSTIC INDEX FOR NAILFOLD CAPILLAROSCOPIC EXAMINATION FOR IDENTIFYING RAYNAUD'S PHENOMENON AT HIGH RISK OF DEVELOPING INTO A SCLERODERMA SPECTRUM DISORDER
F. Ingegnoli1, R. Gualtierotti1, P. Boracchi2, C. Lubatti1, L. Zahalkova1, S. Zeni1, F. Fantini1. 1Rheumatology, G. Pini, University of Milan; 2University of Milan, Institute of Medical Statistics and Biometry, Milano, Italy
Background: Nailfold capillaroscopy has been proposed as a first-line investigation in the early differential diagnosis of Raynaud's phenomenon (RP) because it is simple, non-invasive and inexpensive, but the lack of guidelines concerning the interpretation of the most relevant capillaroscopic abnormalities may hinder its widespread use.
Objectives: To construct a prognostic index based on nailfold capillaroscopic examinations that is capable of predicting the 5-year transition from ''isolated'' RP to RP secondary to scleroderma spectrum disorders.
Methods: The study involved 104 consecutive adult subjects with a clinical history of ''isolated'' RP, and the index was externally validated in another cohort of 100 subjects with the same characteristics. Both groups were followed up for 1-8 years. Six variables were examined because of their potential prognostic relevance (branching, enlarged and giant loops, capillary disorganisation, microhemorrhages, and the number of capillaries).
Results: The only factors that played a significant prognostic role were the presence of giant loops (hazard ratio [HR]: 2.64; p=0.008) and microhemorrhages (HR: 2.33; p=0.01), and the number of capillaries analysed as a continuous variable. Their adjusted prognostic role was evaluated by means of multivariate regression analysis, and the results were used to construct an algorithm-based prognostic index. The model was internally and externally validated.
Conclusion: Our prognostic capillaroscopic index identifies RP patients at high risk of developing scleroderma spectrum disorders. This model is a weighted combination of different capillaroscopic parameters that allows physicians to stratify RP patients easily using a relatively simple diagram to deduce prognosis. Our results suggest that this index could be used in clinical practice, and its further inclusion in prospective studies will undoubtedly help to explore its potential in predicting treatment response.
Ann Rheum Dis 2008;67(Suppl II):563
Session: Diagnostics and imaging procedures