Nail fold capilaroscopy in autoimmune diseases

Abstract

Nailfold capillaroscopy is a non-invasive me­thod for in vivo observation of micro - circulati­on. Several studies have been presented showing the relationship between capillary morphology and the presence of auto-immune diseases. Others, addressed the relationship between specific cha­ racteristics found in essential hypertension, di­abetes and duration of disease. Nevertheless,few quantitative controlled studies have been perfor­med.

The authors present a case control study in a population of women with diagnosed auto-im­mune diseases and a population of healthy con­trols.

Twenty consecutive women from the Out-pati­ents Clinic of the Auto-immune Diseases Unit, were considered (9 patients with systemic lupus erythe­ matosis (SLE), 7 with systemics sclerosis (SS) and 4 with other auto-immune diseases). Patients with hypertension, diabetes, hypercholesterolemia, or primary vascular disease were excluded. A po­pulation of 20 healthy, age and sex matched controls was recruited among the hospital staff. Nail­fold capillaroscopy was performed with a video stereomicroscope, and quantitative measurements were evaluated with the use of a metric scale included in the ocular system. The observations were performed in the sarne room, with a stabi­lised temperature. For each patient and control, measurements were made regarding capillary density and diameter, and the presence ofminor or major structural changes. The fagrell index was used to access the global micro-vascular damage.

Statistical significance was found with capi­llary density (p<0.003), diameter (p<0.009), and the presence of minor (p<0.001) and major (p<0.002) structural changes, between patients and controls. The fagrell index was also signifl­cantly different ( p< 001). Lupus and systemic sclerosis patients were compared and differen­ces were found regarding major structural chan­ges (p<0.02) and the Fagrell index (p<0.01), with higher values for SS patients.

The control group was compared with the SLE patients and the presence of minor structural changes was found more frequently in the Lu­pus group (p<0.0001 ). The other parameters eva­luaded showed no significant difference. The SS patients showed differences regarding the capi­ llary density (p< 0.0001) and diameter (p<0.0001) as well as the presence of major structural chan­ges ( p<0.01).

The results highlight the importance of nail­ fold capillaroscopy in the evaluation of patients with auto-immune diseases. The differencesfound are consistent with the micro-vascular involve­ ment in these diseases. The diferent patternfound in SS and in SLE patients, can be explained by the different pachophysiology of these diseases. Fagrell classification canbe an important index to evaluate the severity and evolution of the pa­thological ftndings.