Immunological investigations in 2 families with progressive diaphyseal dysplasia

Immunological studies were done in members of 2 families with progressive diaphyseal dysplasia. In one family 10 patients and 5 healthy consanguineous relatives were studied, and in the second family one patient and 4 healthy consanguineous relatives were investigated. Evaluation included serum immunoglobulin and complement levels, peripheral blood mononuclear cell subpopulations and lymphocyte stimulation by mitogens. Immunoglobulin and complement levels were normal. All patients had markedly elevated proportions of OKM1 positive mononuclear cells and some of the healthy consanguineous relatives also exhibited the same abnormality. Proliferative responses of lymphocytes to phytomitogens were generally normal. This abnormality of mononuclear cell subset seems to serve as a marker of the disease and may reflect immune mechanisms involved in this disorder.