High incidence of serum monoclonal Igs detected by a sensitive immunoblotting technique in B-cell chronic lymphocytic leukemia.
In a prospective study in 65 untreated patients with early-stage B-cell chronic lymphocytic leukemia (B-CLL), serum monoclonal Igs (moIg) were evidenced in 80% of cases by a sensitive immunoblotting procedure. These low-abundance moIg were generally undetectable by immunoelectrophoresis and individual sera often contained several of them. Their kappa/lambda ratio was close to 1 instead of 2.8 for the lymphocyte surface Igs. A monoclonal IgM of the same light-chain type as the lymphocyte surface IgM was found in 26 sera only. The distribution of the heavy-chain classes and subclasses and light-chain types of the serum moIg was similar to those observed in aging (with a higher incidence and no correlation with age in B-CLL) and conditions with defective T-cell functions. Using a specific filter affinity-transfer assay, rheumatoid factors were detected in 58.5% of sera. However, homogeneous anti-IgG antibodies corresponding to a monoclonal IgM of the same light-chain type as the surface IgM were found in 10 patients only. These data suggest that the majority of discrete serum moIg in B-CLL are not secretion products of the leukemic clones and likely result from the immunodeficiency state inherent in the disease.
Beaume
A
A
Laboratory of Immunology and Immunopathology (CNRS URA 1172), Poitiers, France.
Brizard
A
A
Dreyfus
B
B
Preud'homme
J L
JL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000097:blood* / Q000302:isolation & purification; D004587:Electrophoresis, Agar Gel; D005260:Female; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D007132:Immunoglobulin Isotypes / Q000097:blood / Q000302:isolation & purification; D007145:Immunoglobulin kappa-Chains / Q000097:blood; D007146:Immunoglobulin lambda-Chains / Q000097:blood; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D007132:Immunoglobulin Isotypes; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains