Mickaël Catinon

Develop and validate a thorough exposure questionnaire to comprehensively explore crystalline silica (SiO₂) exposure in the general population (gender-specific, occupational and non-occupational) and in patients with autoimmune diseases (Rheumatoid arthritis (RA), Systemic sclerosis (SSc)). Lifetime exposures to SiO₂ in occupational and non-occupational settings were assessed using a thorough exposure questionnaire. The questionnaire was applied to a general population panel (N = 2,911) sampled from the French rolling census, and to unselected patients with SSc (N = 100) and RA (N = 97). Global (GES), occupational (OES) and non-occupational (NOES) exposure scores were assessed in SSc and RA patients, and compared with up to 4 controls from the general population, matched by age group, sex and tobacco consumption. Patients had higher GES than their matched controls (SSc: p= 0.001; RA: p< 0.0001) due to higher OES (p< 0.0001 for SSc and RA). Men had higher GES than women (SSc: p< 0.0001; RA: p= 0.002) due to higher OES (p< 0.0001 for SSc and RA). The NOES did not differ between men and women. In SSc patients: Men had higher GES than controls (p< 0.0001). Men and women with SSc had higher OES than controls (p< 0.0001). In RA patients: GES and OES were higher in both men (p= 0.00521; p< 0.0001) and women (p< 0.0001; p< 0.0001) than in their respective controls. Women had higher NOES than controls (p= 0.045). The lifetime SiO₂ exposure gap between RA and SSc patients and controls was substantially due to occupational exposure. In both diseases, men had higher exposure scores than women.

BACKGROUND:The case of a patient with bilateral renal cancers diagnosed at 94 and 120 months after metal-on-metal hip placement may serve as a warning. It suggests that there may be a need for kidney echography observation of patients with similar types of prostheses. CASE REPORT:A 61-year-old woman received a metal-on-metal hip prosthesis for degenerative arthritis in January 2007. In November 2014, after bleeding from the renal tract, she was diagnosed with clear cell carcinoma of the right kidney. When she returned to her orthopaedic surgeon 1 year later, a blood test showed a serum cobalt level that exceeded the French medical agency recommendation. After the patient’s metallic acetabulum was replaced in September 2015, her blood cobalt level fell. However, in February 2017, she was diagnosed with adenocarcinoma of the left kidney. Laser-induced breakdown spectroscopy (LIBS) showed cobalt, chromium, and silica overload in both the patient’s kidneys despite the drop in serum levels. CONCLUSIONS:In this case, exposure to a cobalt-chromium implant with high particulate wear, LIBS results showing chromium overload of the kidneys, diagnosis of renal cancer at 7 years, 10 months and 10 years in a patient with a metal-on-metal hip prosthesis suggests that there may be a causal relationship between the implant, carcinogenic chromium intoxication, and development of renal cancer.