Characterization of hypocholesterolemia in myeloproliferative disease. Relation to disease manifestations and activity.

Characterization of the hypocholesterolemia observed in polycythemia vera and agnogenic myeloid metaplasia revealed significant reductions in plasma total cholesterol, low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol in an age- and sex-matched comparison with the Framingham population. Men with myeloproliferative disease also had significantly lower total and LDL cholesterol levels than did those with relative or secondary polycythemia. LDL and HDL cholesterol were significantly correlated, suggesting a generalized disturbance of cholesterol metabolism, unexplained by nutritional status. Evaluation of the relationship among hematic cell proliferation, degree of myeloid metaplasia and hypocholesterolemia by multiple regression analysis revealed that spleen size was the variable of most significance in explaining the variation in plasma total, LDL and HDL cholesterol levels. Uncontrolled disease activity was accompanied by a decline in LDL cholesterol levels. Splenectomy or control of proliferation with chemotherapy or splenic irradiation reversed this abnormality. Levels of plasma total and lipoprotein cholesterol provide information that may be of value in diagnosis and assessment of myeloproliferative disease activity.