Immunological deficiency in myelofibrosis.

An immunological study has been made of 12 patients with myelofibrosis. The study included determinations of serum protein and immunoglobulin concentrations, serial tuberculin skin tests, and in vitro stimulation of peripheral lymphocytes with phyto-haemagglutinin (PHA). In two patients, very low gammaglobulin values were found (low IgG and IgA concentrations; low IgM in one of them). Four other patients had subnormal IgA values. Depressed delayed-type hypersensitivity reactions were observable in four of eight patients tested. The immuno-deficiency noted was probably secondary to the bone marrow damage. Nevertheless, a disturbed immune response may contribute to the development of bone marrow fibrosis and myeloid metaplasia.