Бюллетень сибирской медицины (Aug 2010)
Tick-borne encephalitis: immunological indicators of possible transformation of acute process into chronic disease
Abstract
Several autoimmune diseases with chronic clinical course are characterized by detection of DNA autoantibodies in patients’ serum, while there are no such IgGs in healthy donors’ blood or in patients with acute clinical course with no evidence of chronization. Tick-borne encephalitis has not been considered this way. Several strict criteria have been applied to show that the DNase activity is an intrinsic property of IgGs from the sera of TBE patients but not from healthy donors. The relative activity of IgGs has been shown to vary extensively from patient to patient, but most of the preparations (91%) had detectable levels of the DNase activity. Polyclonal DNase IgGs were not active in the presence of EDTA or after a dialysis against EDTA, but could be activated by several externally added metal ions, with the level of activity decreasing in the order Mn2+ + Ca2+ ≥ Mn2+ + Mg2+ ≥ Mn2+ ≥ ≥ Mg2+ + Ca2+ ≥ Ca2+ ≥ Mg2+ > Ca2+, while K+ , Na+ , Ni2+, Zn2+, and Cu2+ did not stimulate DNA hydrolysis. Affinity chromatography on DNA-cellulose separated the DNase IgGs into many subfractions with various affinities for DNA and very different levels of the relative activity. Possible reasons for catalytic diversity of polyclonal human Abzs are discussed.
Keywords