Circulating immune complexes and the prognosis of acute myeloid leukemia.

We studied the relation between the clinical course and the presence of circulating immune complexes at diagnosis and/or during complete remission in 186 patients with acute myeloid leukemia. Patients with immune complexes at diagnosis had significantly fewer complete remissions (32 vs. 94 per cent), remissions of shorter duration (median, 4.3 vs. 15.0 months), and shorter survival times (median, 1.8 vs. 22.3 months) than patients without such complexes (all comparisons, P less than 0.01). All patients with immune complexes during the first two months of remission remained in remission for less than six months, whereas only 11 per cent of patients without complexes within this period had such early relapse. Of 23 patients who relapsed after long remissions, 18 (78 per cent) had immune complexes that preceded hematologic evidence of relapse by three weeks to six months (median, 3.7 months). These findings suggest that circulating immune complexes may reflect an important aspect of the pathophysiology of acute myeloid leukemia, and that measurement of these complexes can provide useful prognostic information at diagnosis and during remission.

Clinical relevance of circulating immune complexes in human leukemia. Association in acute leukemia of the presence of immune complexes with unfavorable prognosis.

The occurrence of circulating immune complexes was investigated in 467 serum samples from 230 leukemia patients using the [(125)I]Clq-binding test. There was an increased serum [(125)I]Clq-binding activity in 40% of patients with acute myeloid leukemia, 23% with acute lymphatic leukemia, 46% in blastic crisis of chronic myeloid leukemia, 12% with chronic lymphatic leukemia, and 13% with chronic myeloid leukemia. In 48 patients, serum was also tested for soluble immune complexes by the Raji cell radioassay; the correlation between results of the two tests was significant. The Clq-binding material had properties identical with those of immune complexes. It sedimented as 14-28s material on sucrose density gradient. It contained IgG which could be dissociated at acid pH. Its Clq-binding properties could be removed after passage through anti-IgG immuno-absorbant or after a mild reduction-alkylation treatment, but were not sensitive to deoxyribonuclease treatment. Circulating immune complexes were found most commonly during the blastic stage of leukemia.Remission took place in 75.4% of patients with no detectable circulating immune complexes at the onset of acute leukemia, but in only 32.7% of those with detected complexes during this period. Median survival times of the former group of patients were more than 18 mo in acute myeloid leukemia and acute lymphatic leukemia and more than 8(1/2) mo in blastic crisis of chronic myeloid leukemia. The corresponding median survival times in the latter patient group were 64, 135, and 90 days. These findings were unrelated to prognostic features already known.