[Antibody-mediated proteolysis of myelin-associated proteins as a new mechanism of control over demyelinization processes in multiple sclerosis].

Natural antibodies possessing catalytic activity present a new group of biologically active substances that are found in various autoimmune diseases such as autoimmune thyroiditis, myocarditis, multiple sclerosis, and system lupus erythematosus. Presently, an interconnection between the activity of these antibodies and the extent of organic and tissue lesion in autoaggression have been revealed. Clinical use of catalytic antibodies as a diagnostic criterion to evaluate the severity of disease, a prognostic criterion of the risk of invalidization, and as a pathogenetic basis for medicamentous treatment of autoimmune process is a promising directions of study of the role of catalytic antibodies.

[Catalytic autoantibodies as a new molecular instrument in rheumatological practice].

AIM: To compare clinicopathogenetic value of DNA-hydrolizing autoantibodies or DNA-abzymes in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). MATERIAL AND METHODS: We studied sera from 180 patients with SLE, 180 RA patients and 128 healthy donors matched by age and gender; assessed catalytic and cytotoxic activity of DNA-abzymes in patients with different variants of SLE and RA course. RESULTS: The highest catalytic and cytotoxic activities of DNA abzymes were observed in SLE patients. In SLE catalytic and cytotoxic activities of DNA abzymes ranged widely and their mean values depended on SLE activity in patients with systemic lesions. DNA-abzymes in RA patients showed lower catalytic and cytotoxic activities in relation to substrate DNA and target cells than in SLE. DNA-abzymes occurred most frequently in patients with high activity of RA, slow-progressive and lingering course of RA, especially in early development of visceral (extra-articular) pathology. Characteristic for DNA-abzymes in RA and SLE is the phenomenon of wide-range fluctuations due to factors determinating probability of induction of function of Ab-mediated catalysis and, therefore, incidence rates of DNA-abzymes, probably catalytic autoAb of the other specificity in a population of patients with systemic autoimmune diseases. CONCLUSION: The data indicate the validity of DNA abzymes use in clinical practice for realization of diagnostic and therapeutic programs in SLE and RA.

[Catalytic autoantibodies--a new molecular instrument in cardiology and ophthalmology].

AIM: To develop a conceptual model of using catalytic autoantibodies as diagnostic and monitoring tools in organ-specific autoimmune disorders. MATERIAL AND METHODS: A total of 99 patients (56 males and 43 females aged 21-52 years) with autoimmune myocarditis (AM) and 198 patients (77 males and 121 females aged 8-79 years) with autoimmune uveitis (A U) participated in the study. AM patients were examined for anticardiomyosin and anti-DNA autoantibodies (ACM, ADNAab), AU patients - for autoantibodies to S-antigen, IRBP, redopsin, phosphocine, autoDNA. RESULTS: AM patients had double level of DNA-binding autoantibodies. In 1/3 of them there was hydrolysing DNA and cytotoxic activity. In AU patients maximal titers were in Behcet's disease, sympathic ophthalmia, generalized uveitis and viral uveitis. CONCLUSION: Autoantibodies with different specificity and function including DNA-abzymes can be additional diagnostic and prognostic markers.