Seventy-six children with acute lymphoblastic leukemia (ALL) were examined for T- and B-cell markers (sheep erythrocyte receptors and surface immunoglobulins, respectively) on leukemic cells. B-cell-associated or Ia-like antigen (Ia) and ALL-associated antigen (ALLA) were also assayed with indirect immunofluorescent technic using anti-EP and anti-ALL respectively. Four patients were found to have T-cell ALL; one patient was not classifiable, owing to changing expression of markers. Seventy-one patients had null-cell ALL without the T- or B-cell marker; 58 of these patients were ALLA positive (+). ALLA(+) patients were invariably Ia(+). The percentage of ALLA(+) cells closely correlated with the percentage of blast cells in the blood. Thirty-nine healthy subjects, 38 patients without leukemia and 54 patients with other leukemias were studied as negative controls for anti-ALL. Cells from some control subjects showed anti-ALL reactivity. Their cells also demonstrated nonspecific stains in the indirect immunofluorescent technic when normal rabbit serum was used instead of anti-ALL. Preincubating cells with human IgG and goat antihuman IgG eliminated the nonspecific stain on lymphoid cells, presumably by preempting Fc-receptors on the cell surface. With incorporation of this step to the immunofluorescent technic, mononuclear cells from the control subjects and marrow cells from patients with ALL in remission did not react with the anti-ALL. Enumeration of anti-ALL cells may be used to monitor disease activity in patients with ALL.
ASJC Scopus subject areas
- Pathology and Forensic Medicine