APOPTOTIC CELLS IN PERIPHERAL-BLOOD FROM PATIENTS WITH LOW SERUM COBALAMIN

Apoptotic leukocytes were found by using ultrastructural and light mic roscopic techniques to examine peripheral blood in ten of twelve patie nts with low serum cobalamin (vitamin B12) and rarely in normal contro ls. A total of 88 apoptotic cells (.14% of total leukocytes) were iden tified in all the patients. One patient also had apoptotic cells found on a routine blood smear. There was no correlation between the findin g of these cells and nuclear hypersegmentation, serum cobalamin levels , serum intrinsic factor antibody serum methylmalonic acid and homocys teine or the Schilling test. Two patients, however, with the most se w ere vitamin deficiency did not have increased numbers of apoptotic cel ls suggesting that these patients had lost the ability to initiate the cell death program.