Immunological studies of patients with asbestosis. II, Studies of circulating lymphoid cell numbers and humoral immunity.

As part of an overall assessment of immunological function, several aspects of humorial immunity and circulating lymphocyte subpopulations were evaluated in a group of twenty-six patients with radiographic evidence of parenchylmal asbestosis. Statistical comparisons were made between the patient group and a comparable group of forty-five controls. Both the percentages and absolute numbers of circulating T lymphocytes were significantly reduced in the patient group compared with controls. Significant elevations of salivary secretory IgA and of serum IgA, IgG, IgM and IgE were noted amongst the patients compared with the controls. Non-organ-specific autoantibodies and cold-reactive lymphocytotoxins were present in high frequency in the patients' sera. Neoplasms were detected in four of the patients. The possible significance of these findings is discussed.