**6. Nailfold capillaroscopy in systemic disorders with vascular involvement**

## **6.1 Antiphospholipid syndrome (APS)**

*Vascular Biology - Selection of Mechanisms and Clinical Applications*

*Tortuosity (arrow) in a patient with Behçet disease (4th finger of the left hand). Images were taken using Videocap biomicroscope, version 3.0, magnification ×200. Courtesy of Nailfold Capillaroscopy Clinic of* 

*Cryoglobulinemic vasculitis. The image reveals tortuosity (arrow), bifurcation with altered orientation (triangle), and neoangiogenesis (star) (2nd finger of the right hand). Images were taken using Videocap biomicroscope, version 3.0, magnification ×200. Courtesy of Nailfold Capillaroscopy Clinic of Hospital Curry* 

tortuosity, and branching capillaries. No statistically significant correlation was found between NFC abnormalities and organ involvement, but Zampetti et al.

There was no available data about NFC in anti-glomerular basement membrane disease and hypocomplementemic urticarial vasculitis-former anti-C1q vasculitis.

Behçet disease (BD) relationship with NFC alterations have been described in some studies, but they all used different technical characteristics for visualization of microcirculation [42, 49–51]. The main NFC abnormalities include enlarged capillaries, microhemorrhages, reduced density, and tortuosity (**Figure 15**). None of them were related with disease activity. Still, some NFC alterations were described as being related with clinical aspects of BD: NFC severity corresponded to longer disease duration and positive pathergy test; enlarged capillaries were associated with younger age at disease onset, high blood pressure, and superficial phlebitis. We did not find any information about capillaroscopy in Cogan syndrome.

In rheumatoid vasculitis, some studies correlated with capillary damage and levels of soluble intracellular adhesion molecule-1 (sICAM-1), which is highly expressed during inflammation [52–54]. They found abnormalities in the great majority of

described normalization of the edema after 6-month follow-up.

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**Figure 15.**

**Figure 14.**

*Cabral.*

*Hospital Curry Cabral.*

**5.4 Variable vessel vasculitis**

**5.5 Vasculitis associated with systemic disease**

Since APS does not derive from connective tissue, we consider more appropriated to approach it in a separated part of this chapter. Capillaroscopy has been studied in APS and attempts were made to include it as a diagnostic tool [57]. NFC findings include microhemorrhages and dilated loops. Long loops and slow flow sludge capillaries are suggestive of a primary APS, while hemorrhages are typical of secondary APS [19] (**Figure 16**). A specific pattern of microhemorrhage, symmetrically disposed, has been called the "comb-like" hemorrhage and is highly associated to APS [1]. Further, positivity for anticardiolipin antibody has been related to higher prevalence of hemorrhages [58]. In spite of this, and even if microhemorrhages significantly correlate with the diagnosis of APS and its clinical manifestations, NFC findings are not sufficient to establish APS diagnosis for its lack of sensitivity and specificity.

#### **6.2 Diabetes mellitus (DM)**

In DM, NFC changes are apparently associated to the level of glycemic control and the existence of chronic microvascular complications [9]. However, there is an elevated prevalence of comorbidities concurring for microangiopathy, especially in type 2 diabetes, including arterial hypertension, dyslipidemia, and obesity. Still, a "diabetic capillaropathy" was described, which includes tortuosity, capillaries with bizarre shapes, loop dilations, and avascular areas [9, 59]. No differences were found between type 1 and 2 DM, but microvascular complications detected with NFC were correlated with diabetic peripheral neuropathy [60]. It has also been demonstrated that even in prediabetic patients, microangiopathy can already be

#### **Figure 16.**

*Antiphospholipid syndrome in three different patients, revealing tortuosity (arrow), ingurgitated venous plexus (plus sign), long capillaries (two-way arrow), slow flow sludge (dashed arrow), and "comb-like" hemorrhages (\*\*\*). Images were taken using Videocap biomicroscope, version 3.0, magnification ×200. Courtesy of Nailfold Capillaroscopy Clinic of Hospital Curry Cabral.*

detected. So, it is reasonable to suggest that capillaroscopy could be included in the screening of DM-related complications, since it can easily detect microvascular damage at a peripheric level.
