BACKGROUND

Ultrasound examination is currently considered one of the effective methods for diagnosing localized scleroderma (LS). Available descriptions of the ultrasound pattern of LS are few and contradictory. A deeper understanding of patterns can be achieved by correlating clinical and sonographic data with the results of histological and immunohistochemical studies.

OBJECTIVE

To develop sonographic criteria to determine the stage and activity of LS.

MATERIALS AND METHODS

Data from clinical, ultrasound, histological and immunohistochemical examinations were analyzed in 32 patients with LS. Ultrasound examination was performed on a high-class ultrasound scanner using a linear transducer with operating frequencies of 16 and 10 MHz. Material for histological examination was sampled under ultrasound control from the area with the most pronounced changes in the skin and subcutaneous tissue. Histological slides were stained with hematoxylin/eosin and Van Gieson. Immunohistochemical studies evaluated the expression of type IV collagen and vimentin in the skin, which was reported as the ratio of average values of staining intensity indices (Iavg Collagen IV/Iavg Vimentin).

RESULTS

At the stage of erythema/edema of LS, the ultrasound study revealed dermis thickening and increased echogenicity, "blurring" of the margin of the dermis/hypodermis complex, and small foci of reduced echogenicity (both in the dermis and at the border with hypodermis) and hypodermic edema. The Iavg Collagen IV/Iavg Vimentin ratio at this stage ranged from 1.06 to 1.1. At the stage of sclerosis, thinning of the dermis/hypodermis complex with an increase in its echogenicity was observed. The Iavg Collagen IV/Iavg Vimentin ratio decreased to 1.0 at this stage. At the atrophy stage, a thinning of the dermis/hypodermis complex and a decrease in the hypodermis echogenicity were observed. The Iavg Collagen IV/Iavg Vimentin ratio at this stage increased to 1.2–1.3 and more depending on the severity of the changes.

CONCLUSION

In LS patients, a correlation between ultrasound and histological and immunohistochemical patterns was found.