B lymphocytes in untreated patients with malignant lymphoma and Hodgkin's disease.

B and T lymphocytes in 37 untreated patients with malignant lymphoma and Hodgkin's disease were studied. B cells in the peripheral blood were investigated with respect to surface immunoglobulins and in a few patients with respect to intracytoplasmic immunoglobulins by means of immunofluorescence. T cell function was studied by direct phytohemagglutinin (PHA) microtest (from the same sample of whole blood), mixed lymphocyte culture (MLC), and by delayed hypersensitivity to various antigens. In the 13 patients with Hodgkin's disease the histologic subtype was nodular sclerosis in nine, lymphocyte predominant in two, mixed cellularity in two. Only one of these patients had disseminated disease (stage IV); he showed impaired cellular immunity, a very low percentage of B cells and low levels of serum immunoglobulins. Of the remaining patients with Hodgkin's disease, with one exception, normal percentages but rather low absolute numbers of B lymphocytes per mm(3) of blood were found. One patient with a low percent and low absolute number of B lymphocytes showed very high serum IgG. Of 24 patients with non-Hodgkin's malignant lymphoma, seven (29%) showed monoclonal B cell proliferation in the peripheral blood (five mukappa, two gammakappa). By morphologic criteria, 14 patients had involvement of bone marrow, five of these had involvement of peripheral blood. Four of the latter five patients showed marked increases in percentages and absolute numbers of B lymphocytes in the peripheral blood reflecting the monoclonal proliferation. In three additional patients monoclonal proliferation of lymphocytes was found by immunofluorescence although the blood smears appeared morphologically normal. Serum immunoglobulin abnormalities without monoclonal B cell proliferation in the peripheral blood were observed in six patients.