Positivity for antiribonucleoprotein antibodies in rheumatic diseases: focus on scleroderma systematica

The review deals with the problem of antibody production in scleroderma systematica (SDS), with a focus on antiribonucleoprotein (RNP) antibodies: frequency, structure, and clinical associations. SDS is a progressive polysyndromic disease with characteristic lesion of the skin, locomotor apparatus, viscera (heart, lungs, digestive tract, and kidneys), and common vasospastic disorders as Raynaud's syndrome, the basis for which are the processes of connective tissue disorganization with a predominance of fibrosclerotic changes and vascular pathology as peculiar endarteritis obliterans. The presence of antibodies to different autoantigens is a distinguishing feature of SDS. Among the patients who meet the classification criteria for SDS, there is a subgroup of patients who are not found to have SDS-specific antinuclear antibodies, but have antibodies to soluble nuclear autoantigens, namely, antibodies to RNP. This type of autoantibodies is described in various systemic connective tissue diseases: systemic lupus erythematosus, dermatomyositis, polymyositis, and SDS. The detection rate of anti-RNP antibodies in SDS varies from 5 to 30% in different ethnic groups. In addition, positivity for anti-RNP antibodies is a characteristic feature of mixed connective tissue disease. A more detailed study of anti-U1-RNP antibody-positive patients with SDS, by identifying a new subtype of SDS, comparing, and searching for dissimilarities of anti-U1-RNP antibody carriers from other well-described phenotypes of SDS, is of interest today. This problem is relevant, by taking into account the personalized approach to following up patients, which is actively being elaborated in rheumatology