Background/Purpose: Intraperitoneal injection of pristane or adjuvant mineral oil (incomplete Freund’s adjuvant) in non-autoimmune strains of mice mainly induces autoantibodies to U1RNP and Su/argonaute2 (Ago2).  Injection of mineral oil as a cosmetic procedure has been commonly performed in certain countries including Mexico, however, inflammatory syndrome among these subjects have been reported. In the present study, autoantibody specificity in patients who had mineral oil injection and inflammatory syndrome were examined and compared with data from animal models.

Methods: Twenty-one cases of patients, who had mineral oil injections (17 buttocks, 9 breast, 5 thigh, 2 legs, 1 face) and developed rheumatologic symptoms after mineral oil injections were studied.  Autoantibodies were tested by immunofluorescence antinuclear antibodies (ANA) using HEp-2 slide, immunoprecipitation (IP) of ³⁵S-methionine-labeled cell extract and anti-Ro52 and U1RNP-70kD ELISA. Autoantibody specificities were compared with those in BALB/cByJ mice that received a single 0.5 ml intraperitoneal injection of adjuvant mineral oils (incomplete Freund’s adjuvant or pristane). Clinical information was from medical record.

Results: By immunofluorescence ANA, 62% (13/21) were positive in nuclear (5 cases), nucleolar (3 cases), mitochondria-like (3 cases), or GW bodies (2 cases) pattern. By IP, one had anti-U1RNP, 2 had anti-Su/Ago2 (both had GW body staining in ANA) and 3 had anti-Ro60.  Two were positive by anti-Ro52 ELISA and one was positive in anti-U1RNP-70kD ELISA (positive for U1RNP by IP).  Among 6 cases with these autoantibodies (2 had more than one), a case with anti-Su+Ro52 had a diagnosis of SLE, however, other 5 cases had non-specific rheumatological symptoms only. It is of interest that anti-U1RNP and –Su/Ago2 that are the main autoantibody specificity induced by adjuvant mineral oils in animal models, was also seen in mineral oil injected human subjects. Prevalences of these antibodies was not as high as pristane-treated mice but similar to those in adjuvant mineral oil-injected mice.

Conclusion: Patients with rheumatologic inflammatory syndrome after mineral oil injections have autoantibody specificity similar to those in mice with adjuvant mineral oil-induced autoimmunity (anti-U1RNP and Su/Ago2). In addition, they also developed anti-Ro60 and Ro52.

Table. Prevalence of autoantibodies by immunoprecipitation