Cytogenetic studies and in vitro colony growth in patients with mastocytosis.

Cytogenetic analysis of bone marrow cells and in vitro growth for bone marrow granulocytic-macrophage stem cells have been performed in 13 patients with mastocytosis, six with systemic mastocytosis, and seven with urticaria pigmentosa. Clones with chromosome abnormalities were found in five patients. The number of clusters and/or colonies after seven days in culture was increased in seven patients, compared with the growth in a control group. Three patients with chromosome abnormalities showed an abnormal growth pattern, yet exhibited normal peripheral blood values. Two patients with systemic mastocytosis had clones with chromosome abnormalities and some abnormal hematological values. The proportion of patients with chromosome abnormalities and an abnormal growth pattern was higher among these patients with mastocytosis than in healthy control subjects. These results may be of interest when discussing the origin of mast cell disorders and indicate an association with the myeloproliferative disorders.