Monoclonal and/or Oligoclonal Immunoglobulins in Sera of Patients with Non-Hodgkin's Lymphomas, Determined by Iso-Electric Focusing and Immunoblotting

Sera from 60 patients with non-Hodgkin's lymphomas (NHL) were tested by isoelectric focusing (IEF) and immunoblotting (IB) techniques for the presence of monoclonal or oligoclonal immunoglobulins (Ig). Of the 60 NHL patients, 18 were newly diagnosed and had not received any treatment while the rest had received some chemotherapy in the past. Two serum samples were obtained from 27 patients over the treatment period. Oligoclonal Ig patterns were detected in 34 of the 60 (56.6%) sera, and were further identified by IB as IgG of mixed kappa (K) and lambda (λ) types. Seven of the 18 (38.8%) newly diagnosed NHL patients had these oligoclonal bands, compared with 27 of the 42 (69%) who had received chemotherapy in the past. In 11 of these 27 (40.7%) patients, follow-up studies revealed the appearance of new Ig bands (9 cases) with the disappearance of preexisting ones (2 cases). After treatment of sera with 2-mercaptoethanol, monoclonal IgM was detected in 39 of the 60 (65%) NHL patients. These monoclonal Ig spikes occurred together with oligoclonal IgG (20/60 cases) or appeared in the absence of oligoclonal IgG (19/60 cases), while oligoclonal IgG could also appear as the sole serum finding (14/60 cases). There was a higher prevalence of monoclonal IgM among patients with stage IV disease and of oligoclonal IgG among patients with high grade of malignancy NHL. Our results demonstrate that among patients with NHL there is a high prevalence of monoclonal or oligoclonal Ig bands detected by highly sensitive methods such as IEF and IB.