Immunophenotypic diagnosis of clinical and preclinical chronic lymphatic leukemia by using monoclonal antibodies against the cCLLa, a CLL-associated antigen.
The clinical usefulness of monoclonal antibodies (MoAbs) against the cCLLa, an antigen restricted to B-chronic lymphatic leukemia (CLL) and its variants, was ascertained in 65 patients with overt CLL and 25 individuals with unexplained mild lymphocytosis. Healthy volunteers (n = 25) and patients with malignant and nonmalignant disorders (n = 58) served as controls. The following observations were made in CLL. (a) Anti-cCLLa MoAbs identified neoplastic CLL cells as judged by the high correlation (r = .985) between monoclonal surface immunoglobulins (Slgs) and cCLLa expression in all patients, and dual-label flow cytometry studies showing cCLLa expression by monoclonal Slg-bearing B-CLL cells but not by normal B lymphocytes. (b) The size of the circulating cCLLa-positive clone paralleled the degree of lymphocytosis (r = .987) and was associated with reciprocal (r = .893) relative T lymphopenia. Ten patients with borderline lymphocytosis exhibited a subset of monoclonal Slg/cCLLa-positive cells ranging from 16% to 45% of the total. These patients were indistinguishable from those with CLL in terms of age, clone lineage, and reciprocal relative T lymphopenia. Two patients have progressed to overt CLL within 19 months, but eight have not (observation time, 18 to 82 months). These data suggest that anti-cCLLa MoAbs are sensitive probes useful to identify and monitor cCLLa clones during their clinical and preclinical phases.
Faguet
G B
GB
Medical Service, VA Medical Center, Augusta, GA 30910.
Agee
J F
JF
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis*; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis; D007945:Leukemia, Lymphoid / Q000175:diagnosis* / Q000276:immunology; D007958:Leukocyte Count; D008875:Middle Aged; D009367:Neoplasm Staging; D010641:Phenotype
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D007075:Immunoglobulin M