Depressed PHA transformation and acute leukemia in macroglobulinemia

Two out of fifty-three patients with macroglobulinemia developed acute leukemia following chemotherapy. The Phytohemagglutinin (PHA) Transformation Index performed prior to the appearance of acute leukemia was found to be markedly depressed in these two patients in comparison with ten other patients with macroglobulinemia. In addition, a clone with monosomy 7 was detected in one of the currently reported patients when the leukemic process became apparent. The cytogenetic analysis was normal in the same patient 48 months earlier, when macroglobulinemia was diagnosed. The low PHA Transformation Index and the chromosomal hypodiploidy are of interest and their clinical significance merits further investigation.