B-cell lymphoma of the mucosa-associated lymphatic tissue (MALT) presenting with bone marrow and peripheral blood involvement.

A 46-year-old female patient was diagnosed as having a low-grade malignant B-cell lymphoma of the gastric MALT, stage IV, with bone marrow involvement and a leukaemic blood picture. Different from the infiltrate in the gastric mucosa, which consisted mainly of centrocyte-like cells, the leukaemic cells presented with a blood-picture resembling infectious mononucleosis but showing a predominance of plasma cells. Despite these cytological differences, a common clonal origin for both cellular compartments was demonstrated immunophenotypically and genotypically. Low-grade B-cell lymphomas of the MALT may thus initially present with stage IV disease and a leukaemic blood picture.

Spectrum and frequency of autoimmune derangements in lymphoproliferative disorders: analysis of 637 cases and comparison with myeloproliferative diseases.

The records of 637 patients with lymphoproliferative disorders and 346 patients with myeloproliferative disorders were retrospectively analysed for the presence of additional autoimmune derangements. The frequency of autoimmune perturbations in lymphoproliferative diseases (51 cases; 8.0%) was significantly higher than in myeloproliferative diseases (six cases; 1.7%; P less than 0.0001). Rheumatic disorders, autoallergic haematological manifestations and other organ-specific autoimmune derangements were responsible for about one third each of the observed disturbances. Autoimmune diseases which preceded the onset of malignancy, occurred in lymphoproliferative and myeloproliferative disorders with a comparable frequency without significant differences between individual subgroups of lymphoproliferative diseases. In contrast, autoimmune complications developing in the course of the neoplastic disease were significantly more frequent in lymphoproliferative (4.9%) than in myeloproliferative disorders (0.3%; P less than 0.0005). Here marked differences were observed between individual lymphoma entities, the rate of concomitant autoimmune derangements ranging from zero to over 15%. With the exception of centroblastic-centrocytic lymphoma which in no case was associated with secondary autoimmune complications, the proportion of patients with autoimmune perturbations increased with improving prognosis of the lymphoproliferative diseases. Possible pathogenetic mechanisms involved in the manifestation of autoimmune complications in malignant lymphomas are discussed.

Sequential expression of fucosyltransferase and N-acetylneuraminyltransferase activities in human leukemic cells arrested at different stages of maturation.

Fucosyl transferase (Fuc-T) and N-acetylneuraminyl-transferase (NeuAc-T) activities were determined in lysates of human neoplastic hematopoietic cells arrested at different stages of maturation. Leukemic non-T/non-B lymphoblasts and myeloblasts arrested at a very early stage of maturation displayed high Fuc-T and low NeuAc-T activities. T-lymphoblasts, further developed along the T-lymphocyte lineage, showed increased NeuAc-T activity. In contrast, lymphoid cells further developed along the B-lymphocyte lineage revealed low Fuc-T, and either low or high levels of NeuAc-T activity. These results suggest that during the process of cell maturation the expression of Fuc-T precedes that of NeuAc-T, and that in T-lymphocytes the expression of NeuAc-T is concomitant with the emergence of the T-cell receptor for sheep erythrocytes.

Peripheral blood T and B lymphocytes in men in different age groups.

Peripheral blood T and B lymphocytes were determined in normal humans at different ages. Spontaneous rosette formation with sheep red blood cells (SRBC) was used as a marker for T cells. B cells were detected by immunofluorescent staining of membrane-bound immunoglobulins. Blood samples from old individuals contained significantly lower T lymphocyte numbers than those from children. This diminution of circulating T cells caused a reduction of the total lymphocyte count in the elderly persons. No significant differences were between the T cell values of young and old adults. Whereas the percentages of B cells indicated an increase of this lymphocyte population in old humans, the absolute numbers of B lymphocytes remained almost unchanged during aging.

[Lymphocyte in chronic lymphatic leukemia]. / Der Lymphozyt bei der chronischen lymphatischen Leukämie

In patients with chronic lymphatic leukemia (CLL) the majority of peripheral blood lymphocytes was characterized as B cells by surface membrane markers. Ultrastructural studies revealed a reduction of the cytoplasmic area. Furthermore, the number of lysosomes was diminished corresponding to a decreased activity of lysosomal hydrolases. Increasing blood lymphocytosis was paralleled by an increase of the percentage of lysosome-poor lymphocytes. Response of CLL lymphocytes to in vitro stimulation with PHA and PWM was either lacking or diminished and/or delayed, and the number of transformed cells was reduced. Thus, the majority of CLL lymphocytes appears to represent both morphologically and functionally abnormal neoplastic b cells. During the early and later phase of stimulation the mitogen-reactive CLL lymphocytes exhibited alterations of the lysosomal apparatus similar to those observed in normal cells. The reactive lymphocytes may be derived from residual populations of normally functioning T and/or B cells. However, the neoplastic cells may also be able to respond to the mitogens. In vivo studies showed impaired kinetics of circulation and recirculation of CLL B lymphocytes, whereas the T cells were normal in this respect.