ULTRASTRUCTURE OF PERIPHERAL-BLOOD GRANULOCYTES FROM PATIENTS WITH LOW SERUM COBALAMIN

Peripheral blood granulocytes from ten patients with low serum cobalam in were studied using light and electron microscopic techniques. Six p atients had classic neutrophil hypersegmentation using light microscop y, bur three patients had an increase in band forms and rare hypersegm ented cells. The electron microscope revealed nuclear appendages consi sting of nuclear stalks, rings and blebs in neutrophils from all patie nts regardless of the degree of hypersegmentation but not from normal controls; these did not appear to result from sectioning artifact and their formation may be interrelated. Numerous cytoplasmic empty granul es were seen in neutrophils from three patients. Another three showed what appeared to be granules in the shape of water-wings under low pow er, bur on higher power were unique mitochondria. Some disorder of the eosinophil granule centrum was seen in all patients but was extreme i n four patients; lipid cytoplasmic inclusions were also seen in these four and one other patient.