Profile of immunological markers in skin biopsies from patients with probable and confirmed systemic lupus erythematosus

Abstract

The purpose of this study was to determine the profile of immunoreactants deposited in intact skin biopsies from the patients with confirmed and probable systemic lupus erythematosus. The study involved 94 patients who, along with a standard clinical and laboratory examination, underwent a biopsy of clinically healthy skin in the deltoid muscle area (lupus band test). The nature and combination of immune deposits in the skin, the strength of immunofluorescence, and the location were evaluated. In the patients with significant systemic lupus erythematosus (n = 56), lupus band test was positive in 60.7 % of the cases and correlated with disease activity according to SLEDAI 2K (p = 0.001). At the same time, the skin biopsy often revealed the immunoreactant IgM (85.3 %), the degree of fluorescence of which had direct correlations with the increased level of antibodies to dsDNA (p 0.05). In the examined patients with probable systemic lupus erythematosus, positive lupus band test was detected in 47 % of cases, and IgM was detected in 72.2% of patients, which brought them closer to the group of patients with confirmed systemic lupus erythematosus. However, 33.3% of patients with probable systemic lupus erythematosus had isolated deposits of any one immunoreactant, while the association of immunoreactants (IgM+IgG) and (IgM+IgG+C3) characteristic of confirmed systemic lupus erythematosus occurred in only 27.7 and 5.5% of cases, respectively. It should be noted that the C1q immunoreactant was detected in the skin biopsies with both confirmed (38.2%) and probable systemic lupus erythematosus (39%). The data obtained suggest that lupus band test with the presence of a specific pattern of immunoreactants can be used as an additional diagnostic test for the diagnosis of systemic lupus erythematosus.