Microchimerism and systemic sclerosis

Abstract EN

Objective: The goal of this study is to test the hypothesis whether microchimerism is involved in the pathogenesis of systemic sclerosis (SSc) by detecting the presence of male microchimerism in the maternal peripheral blood and in skin specimens from women affected with SSc.

Methodology: The material of this study consisted of 20 SSc patients (nine limited and 11 diffuse) and 20 apparently healthy controls that had given birth to at least one son.

All of them were subjected to tests to determine the presence of the Y-chromosome-specific DNA sequence (male microchimerism) using the PCR technique in the maternal peripheral blood.

In addition, the FISH analysis with probes specific for X and Y-chromosomes was used in skin biopsy specimens.

Results: PCR analysis showed that SSC patients SSc were more frequently positive for Y chromosome-specific DNA in PBMC (65%) than healthy women (30%).

The frequencies of individuals with detectable male DNA was higher in the diffuse type (8/11, 72.72%) than in the localized or limited disease type (5/9, 55.5%).

Positivity was also higher among SSc patients with anti-topoisomerase I antibodies (7/10, 70%) than among those without the antibody (6/10, 60%), although the difference was not statistically significant.

FISH signals appeared in nuclei from skin sections of 6/9 SSc patients (66.6%).

All male cells found in tissue sections occurred as single cells present within inflammatory-cell infiltrates localized in the extracellular matrix of the deep dermis or in the walls of small vessels.

They were surrounded by female cells within the architecture of the skin tissue.

No FISH signals could be detected in any of the skin sections of the control group.