OCCUPATIONAL exposure to petroleum-derived lubricants has been associated with a higher risk of multiple sclerosis (MS), with stronger associations among smokers and people with established genetic susceptibility, according to a Swedish case-control study.
Lung irritants such as smoking and organic solvents are established risk factors for MS, with effects influenced by genetic susceptibility, particularly the human leukocyte antigen (HLA) variants HLA-DRB1*15:01 and HLA-A*02:01. Petroleum-derived lubricants represent another widespread occupational exposure with potential inflammatory properties, yet their contribution to the aetiology of multiple sclerosis was unclear. This study has therefore investigated associations between occupational petroleum exposure and MS risk, including interactions with smoking and HLA genotypes.
This Swedish population-based case-control study consecutively recruited incident MS cases through neurologists at 40 clinics between 2005 and 2015, requiring residence in Sweden, age 16–70 years, and a neurologist-confirmed MS diagnosis according to the McDonald criteria. Controls were randomly selected from the national population register using density sampling and frequency-matched to cases by age, sex, and residential area. The study population comprised 2,872 MS cases and 6,122 controls (mean age: 34.6 years; 72% female), with HLA data available for 2,070 cases and 2,899 controls. Exposure to petroleum-derived lubricants was assessed using questionnaires.
Occupational exposure to petroleum-derived lubricants was associated with increased MS risk (OR: 1.38), with a modest exposure-duration response, and the association persisted when a 7-year exposure lag was applied (OR: 1.55).
Additionally, a positive interaction was identified between petroleum exposure and smoking (AP: 0.34). Among the subset with available HLA data, petroleum exposure similarly interacted with the absence of HLA-A*02:01 (AP: 0.32). A comparable interaction was observed with HLA-DRB1*15:01 (AP: 0.19), although this estimate did not reach statistical significance.
These findings add to the evidence that lung irritants and gene-environment interactions are associated with MS susceptibility, with petroleum exposure linked to multiple sclerosis risk, particularly among smokers and participants with established genetic susceptibility. However, the findings require replication in independent populations before their wider implications can be established.
Reference
Hedström AK et al. Occupational exposure to petroleum-derived lubricants and risk of multiple sclerosis. Neurology. 2026;107(11)e218718.
Featured image: DusanJelicic on Adobe Stock
Each article is made available under the terms of the Creative Commons Attribution-Non Commercial 4.0 License.
