Petroleum Research Today is a free monthly online journal that collates and summarizes the latest research about Petroleum, including details on crude oil, extraction, chemistry, pollution.

Induction of lupus-related specific autoantibodies by non-specific inflammation caused by an intraperitoneal injection of n-hexadecane in BALB/c mice.

Kuroda Y, Ono N, Akaogi J, Nacionales DC, Yamasaki Y, Barker TT, Reeves WH, Satoh M

Division of Rheumatology and Clinical Immunology, Department of Medicine, ARB-R2-156, 1600 SW Archer Road, Box 100221, Gainesville, FL 32610-0221, USA.

A single intraperitoneal (i.p.) injection of pristane, incomplete Freund's adjuvant (IFA), or the adjuvant oil squalene, but not high molecular weight medicinal mineral oils, induces lupus-related autoantibodies to nRNP/Sm and -Su in non-autoimmune strains of mice. This ability appears to be associated with the low molecular weight and adjuvanticity of hydrocarbon. n-Hexadecane (C(16)H(34)), which is present in petroleum, has adjuvant activity and induces arthritis in rodents like other lupus-inducing oils. In addition to dietary exposure to n-hexadecane in mineral oils, exposure also occurs via inhalation of oil mist, jet fuel, or diesel exhaust or by absorption through the skin. Since n-hexadecane is a low molecular weight adjuvant hydrocarbon oil similar to other lupus-inducing hydrocarbons, the present study examined whether it can also induce lupus-related autoantibodies in mice. Female BALB/cJ mice received a single i.p. injection of 0.5 ml of n-hexadecane, pristane, or saline (control). Pathology and serology (immunoglobulin levels, autoantibodies by immunofluorescence, immunoprecipitation, and ELISA) were examined 3 months later. Unexpectedly, all n-hexadecane-treated mice, but none in the other groups, developed inflammatory ascites within 2.5 months. n-Hexadecane induced hypergammaglobulinemia (IgG1, IgG2a), antinuclear (titer>1:160, 67%) and -cytoplasmic antibodies (58%) and autoantibodies to nRNP/Sm (25%), Su (33%), ssDNA (83%), and chromatin (100%). Therefore, non-specific inflammation caused by n-hexadecane resulted in the production of a limited set of specific autoantibodies. These previously unrecognized immunological effects of n-hexadecane may have implications in monitoring human exposure to hydrocarbons and in the pathogenesis of autoimmune diseases.

Published 26 December 2005 in Toxicology, 218(2): 186-96.
Full-text of this article is available online (may require subscription).

© 2005-2008 Petroleum Research Today. All Rights Reserved.