Immunological Unresponsiveness to Chromium or Nickel in the Guinea-Pig Induced by Stainless Steel Welding Fume Components

Abstract

In contrast to the effects of cutaneous application of chemical haptens, which cause cell-mediated hypersensitivity, their inhalation or oral administration may cause instead a specific immunological tolerance (Doe et al. 1982). Industrial metal fumes from stainless steel processing, e.g. metal arcwelding, contain mixtures of potential haptens such as chromium and nickel, which are capable of causing cutaneous sensitization (Hicks et al. 1979). Particulate components of such fumes are readily inhalable by exposed workers. There is thus a question of whether the haptens may lead to sensitization or if a state of immunological tolerance may result. However, effects of inhaled welding fumes are poorly documented with respect to humans, so these possibilities were investigated in the guinea-pig.

Possible sensitizing or tolerance-inducing effects of material in aqueous solution from fumes generated by manual metal arc welding of stainless steel (MMA-SS), were investigated by pretreatments using three doses of solution at 2-day intervals, followed by a 9-day interval, after which the sequence was twice repeated. In different tests, oral, intratracheal or intrapulmonary routes of administration were employed. Subsequently, treated animals were subjected to skin sensitizing and challenge-testing procedures, using nickel sulphate or potassium dichromate solutions. Lung lavage and peritoneal exudate cells were used for macrophage migration inhibition tests “in vitro”, to indicate systemic senzitisation. Cutaneous application of MMA-SS solutions induced sensitization to chromium and nickel, but prior intratracheal or intrapulmonary injection sequences prevented such development of skin sensitization. Animals pretreated with potassium dichromate sequentially by these routes displayed a similar lack of response to cutaneous sensitization and challenge procedures. These effects were interpreted as production of states of tolerance. Pretreatments with intrapulmonary or intratracheal nickel sulphate provoked systemic sensitization and marginal tolerance respectively. It is suggested that inhalation of welding fume particles containing potential sensitizing haptens might induce immunological tolerance but under same circumstances sensitization might occur instead.