Detection of circulating immune complexes in acute non-lymphatic leukaemia: is it reliable?

The in vivo and in vitro phagocytic ability of leukaemic cells and the serum levels of circulating immune complexes (CIC) have been evaluated in 11 patients affected by acute non-lymphatic leukaemia (ANLL). High levels of serum CIC were detected in 17% of the cases showing phagocytic ability and in 80% of the cases lacking phagocytic ability (p less than 0.05). In 3 patients serum CIC determinations were negative while immunoglobulins with complement-fixing ability were detected in the cytoplasm of leukaemic cells indicating in vivo phagocytosis of CIC. These results suggest that leukaemic cells may sometimes interfere through their phagocytic ability on the detection of CIC in the serum. Therefore, the clinical and prognostic value of serum CIC in ANLL seems questionable.