Effects of interferon-alpha and -gamma on B cell differentiation in macroglobulinemia

Waldenström's macroglobulinaemia: current therapy and future approaches

Waldenström's macroglobulinaemia is a rare B-cell malignancy. It is prevalent in the sixth and seventh decades, the median age at diagnosis being 63 years. Conventional treatment has involved alkylator therapy, especially chlorambucil given daily at a low dose or intermittently at a higher dose. Purine analogues, used initially as salvage therapy in refractory disease, are increasingly used for initial therapy. However, purine analogue therapy entails significant complications, including immunosuppression, pancytopenia and autoimmune haemolysis. Moreover, it is unclear whether purine analogues extend survival. All of these need to be considered before initiation of therapy. More recently, anti-CD20 monoclonal antibody and thalidomide have been used with a 30% response in treated patients. High-dose therapy with stem cell support achieves a partial response in a majority of patients receiving this modality of therapy. The median survival of 5 years has not improved considerably since the introduction of purine analogues. Complete response is still uncommon; using all available modalities of therapy may increase the complete response rate and improve survival. Great strides in understanding the malignant cell, the microenvironment and the potential interactions have identified potential targets for therapy in multiple myeloma. These agents may also be useful in Waldenström's macroglobulinaemia. Since this is a rare malignancy, all patients should be treated with well-designed clinical protocols to achieve improvement in outcome.

IFN-alpha as induction and maintenance treatment of patients newly diagnosed with Waldenström's macroglobulinemia

Waldenström's macroglobulinemia is a rare malignant disorder of B lymphocytes. There are no studies on the use of interferon-alpha (IFN-alpha) as frontline therapy in this disease. Between April 1991 and September 2000, we treated 21 newly diagnosed patients using 8 mg/m(2) chlorambucil and 40 mg/m(2) prednisone p.o. daily for 10 days and 3 megaU/m(2) IFN-alpha three times a week. Patients who responded after induction continued receiving IFN until relapse or death. We found a high frequency of peripheral neuropathy (43%) and grade 3 diffuse marrow fibrosis (43%). Objective response was achieved in 12 (57%) patients, including 4 (19%) complete responders. Median time from treatment to response was 8 months (range 3-18). Median progression-free survival was 70 months (95% CI 47-93), and overall survival was 91 months (95% CI 50-132). Patients who achieved objective response lived longer (91 vs. 33 months, p < 0.03), as did patients who had lactic dehydrogenase (LDH) < 180 U/L (89 vs. 54 months, p < 0.01). Grade 3 hematologic toxicity was observed during induction in 5 patients. IFN-alpha is an effective agent for the induction and maintenance treatment of Waldenström's macroglobulinemia patients. LDH > 180 U/L and failure to respond are adverse prognostic factors.

Waldenström's macroglobulinemia: clinical features, complications, and management

PURPOSE

To review the clinical features, complications, and treatment of Waldenström's macroglobulinemia, a low-grade lymphoproliferative disorder that produces monoclonal immunoglobulin (Ig) M.

METHODS

A review of published reports was facilitated by the use of a MEDLINE computer search and by manual search of the Index Medicus.

RESULTS

The clinical manifestations associated with Waldenström's macroglobulinemia can be classified according to those related to direct tumor infiltration, to the amount and specific properties of circulating IgM, and to the deposition of IgM in various tissues. Asymptomatic patients should be followed without treatment. For symptomatic patients, standard treatment consists primarily of oral chlorambucil; nucleoside analogs, such as fludarabine and cladribine, are effective in one third of previously treated patients and in up to 80% of previously untreated patients. Preliminary evidence suggests that anti-CD20 monoclonal antibody may be active in about 30% of previously treated patients and that high-dose therapy with autologous stem-cell rescue is effective in most patients, including some with resistance to nucleoside analogs.

CONCLUSION

Waldenström's macroglobulinemia has a wide clinical spectrum that practicing physicians need to recognize early to reach the correct diagnosis. When therapy is indicated, oral chlorambucil is the standard primary treatment, but cladribine or fludarabine can be used when a rapid cytoreduction is desirable. Prospective randomized trials are required to elucidate the impact of nucleoside analogs on patients' survival. A nucleoside analog is the treatment of choice for patients who have been previously treated with an alkylating agent.