Allergy to complex salts of platinum in refinery workers: prospective evaluations of IgE and Phadiatop status.

BACKGROUND: Experience has shown some variation in the associations between IgE, atopy, and sensitization to platinum salts. Clarification of these associations, and the value of the parameters in predicting and diagnosing sensitization of workers at risk, required prospective investigation. OBJECTIVES: Evaluation of total IgE and Phadiatop(R) status to establish baseline values, and changes during employment, predictive or associated with subsequent platinum salt sensitization. METHODS: A 24-month prospective study, in a South African primary platinum refinery, of a cohort of 78 healthy recruits without evidence of atopy (tested negative to skin prick test with common allergens). Subsequently they were categorized as 22 sensitized (positive skin prick test to platinum salts), 46 not sensitized (negative skin prick test and symptom free), and 10 symptomatic subjects not included in either category. RESULTS: (1) Pre-employment: four (18%) of the subsequently sensitized subjects and eight (17%) not sensitized were Phadiatop(R) positive. Levels of total IgE > 100 kU/L, present in 16 subjects were associated with positive Phadiatop(R) status and race. (2) During employment: Phadiatop(R) status converted from negative to positive in more sensitized (12/18) than unsensitized (6/38) subjects (P

Platinum salt sensitivity in refinery workers: incidence and effects of smoking and exposure.

OBJECTIVE: To measure the incidence of platinum salt sensitivity (PSS) in refinery workers and examine the influence of cigarette smoking and exposure to platinum salts on sensitisation. DESIGN: A prospective cohort study with examination of workers at quarterly intervals for 18 months, and again at 24 months. SETTING: A South African primary platinum refinery. SUBJECTS: 78 new recruits, selected by the refinery's usual procedure, without apparent atopy and in good respiratory health. RESULTS: After 24 months 32 (41%) subjects had been diagnosed PSS and were subsequently medically separated. Twenty two (28%) cases were confirmed by positive skin prick test to platinum salts, 10 (13%) cases were symptomatic but skin prick negative. Incidence of cases per 100 person-months was 1.9 skin prick positive and 0.8 negative. Risk of sensitisation was about eight times greater for smokers than non-smokers, and six times greater for high exposure than low exposure. CONCLUSION: Smoking and intensity of exposure were definitely associated with development of PSS. Positive responses to platinum salt skin prick test had a 100% positive predictive value for symptoms and signs of PSS if exposure continued.