Circulating Immune Complexes, Immunoconglutinins, and Rheumatoid Factors in Nephropathia Epidemica

Abstract

Circulating immune complexes (CICs), immunoconglutinins, and antiglobulins were studied in nephropathia epidemica, an acute infectious hemorrhagic fever occurring in Finland and Scandinavia. Sixty-one serum specimens from 18 serologically confirmed patients were collected between day -5 and day 230 from the onset of fever. Five CIC tests, three immunoconglutinin tests, and various other tests were used to characterize the disease immunologically. CICs were found in all patients. The percentage detection of positive cases varied in the tests from 100% to 22%. A marked stimulation of levels of the IgM class of immunoglobulins were observed. Antiglobulin tests were positive for all of the patients. No correlation between the test results and the clinical severity of the disease could be found. Of special interest was the delay in the rise of CIC levels compared with the chromologic pattern of the clinical course. In some patients a prolonged appearance of CICs for eight months was observed.

Persistent Infection of Rats with Haemorrhagic Fever with Renal Syndrome Virus and their Antibody Responses

“…Since newborn animals have low T cell activity (Cantor & Boyse, 1975;Haaijman et al, 1981), the immaturity of their T cell functions may result in only a low level of humoral antibodies which is insufficient for clearance of the virus. Penttinen et al (1981) observed a marked increase in IgM class immunoglobulin in patients with nephropathia epidemica. However, in patients the antibody which reacted specifically with viral antigen belonged to the IgG class (Brummer-Korvenkontio et al, 1980).…”

Hantavirus Infection in SCID Mice.

“…Immune mediated pathogenesis as a cause for HFRS has been suggested because of the appearance of the an immune complex [19], complement activation, and disease onset coinciding with antibody response in patients [4,5]. Experimental infection of mice also suggests the immune mediated pathogenicity through the early death phenomenon of newborn mice [1,16].…”

“…There is suggestive evidence, such as coincidence of the humoral immune response with disease onset, appearance of immune complex in kidney [19] and complement activation [4,5] which indicates an immunopathological basis for HFRS. On the other hand, it is also speculated that direct injury by the virus infection is a plausible mechanism for pathogenicity.…”

Increased serum fibronectin levels in patients with hemorrhagic fever with renal syndrome

“…Fibronectin specifically interacts with complexed/polymeric Igs, thereby perpetuating immune complex (IC) deposition and playing a role in the pathogenesis of IC diseases [27]. Immune complexes deposit in the renal tissue and circulation of patients with HFRS [28] and nephropathia epidemica, the European form of HFRS [9,29]. Whether the increased fibronectin plays a role in the pathogenesis of kidney injury by facilitating IC formation and deposition needs to be addressed.…”