Prognostic model based on nailfold capillaroscopy for identifying Raynaud's phenomenon patients at high risk for the development of a scleroderma spectrum disorder: PRINCE (Prognostic Index for Nailfold Capillaroscopic Examination)

Abstract

Objective. To construct a prognostic index based on nailfold capillaroscopic examinations that is capable of predicting the 5-year transition from isolated Raynaud's phenomenon (RP) to RP secondary to scleroderma spectrum disorders (SSDs).Methods. The study involved 104 consecutive adult patients with a clinical history of isolated RP, and the index was externally validated in another cohort of 100 patients 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 disorganization, 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 (analyzed as a continuous variable). The adjusted prognostic role of these factors 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 in whom the risk of developing SSDs is high. This model is a weighted combination of different capillaroscopy parameters that allows physicians to stratify RP patients easily, using a relatively simple diagram to deduce the prognosis. Our results suggest that this index could be used in clinical practice, and its further inclusion in prospective studies will undoubtedly help in exploring its potential in predicting treatment response.Raynaud's phenomenon (RP) is defined as bouts of reversible vasospastic ischemia of the digits that are typically manifested upon exposure to the cold and/or in association with emotional stress. It is characterized by well-demarcated blanching (ischemia), which leads to cyanosis (deoxygenation), followed by postischemic red flushing upon rewarming (reperfusion). A biphasic or triphasic color change may occur. Episodes of RP may be accompanied by varying degrees of paresthesia, numbness, and pain (1,2).Previous population-based studies have shown that RP is a very common problem in clinical practice: its prevalence in the US is ϳ4-9% among women and ϳ3-6% among men (3,4). The prevalence of RP in Europe is 2-21% and is closely related to climatic conditions (5-7).RP may be primary (uncomplicated) when it occurs without an underlying disease or secondary when it develops in the context of an associated disorder.

The role of nail-videocapillaroscopy in early diagnosis of scleroderma

“…A diagnosis of primary RP means that no underlying disease has yet been identified, but it is difficult to predict if and when it may become secondary RP [21], [22], [23] and [24]. Therefore, a follow-up nailfold capillaroscopic analysis is recommended to be performed every 6 months [9] and [10].…”

“…Notably, RP is the first manifestation in about 90% of patients with SSc [24], [33], [34], [35] and [36].…”

Nailfold capillaroscopy in systemic sclerosis: Data from the EULAR scleroderma trials and research (EUSTAR) database

“…Capillaroscopy is a powerful in vivo tool not only in screening patients with Raynaud's phenomenon for underlying scleroderma spectrum disorders (Ingegnoli et al, 2008(Ingegnoli et al, , 2010Nagy and Czirjak, 2004;Vayssairat et al, 1982), but also in detecting the progressive microvascular damage during the course of SSc (Herrick and Cutolo, 2010).…”

Nailfold capillaroscopy microscopy - an interdisciplinary appraisal

“…Another predictive model has shown the need for additional autoimmune diagnostics if capillary density decreases below 8.45/mm in the fi rst row [67,68].…”