In vitro production of monoclonal and polyclonal immunoglobulins by peripheral blood mononuclear cells in human plasma cell myeloma

Higher proliferative response in B-chronic lymphocytic leukemia (B-CLL) as compared to B-monoclonal lymphocytosis of undetermined significance (B-MLUS) after stimulation with Staphylococcus aureus and anti-CD40 monoclonal antibodies

B-CLL is a malignant monoclonal B-cell disorder and B-MLUS is the benign counterpart. The proliferative response and the capacity to secrete IgM was measured in B-CLL and B-MLUS, respectively, and compared to normal B-cells. SAC and a mAb against CD40 were used as stimulatory agents. No cell population responded to anti-CD40 mAb alone. SAC only induced a high DNA synthesis rate in normal B-cells as well as in B-CLL cells, although the magnitude was three-fold lower and delayed for about 48 h in B-CLL. B-MLUS cells did not proliferate in response to SAC. The combination of anti-CD40 and SAC enhanced the proliferative capacity of normal B-cells and produced a more rapid response in B-CLL. B-MLUS cells were not activated. Normal B-cells and B-MLUS did not secrete IgM after SAC stimulation, while B-CLL cells had a continuous increase in the IgM production during a 6-day culture period. The higher proliferative capacity of B-CLL cells compared with B-MLUS cells may be explained by an increased expression of activation molecules e.g. receptors for various cytokines and growth factors. Moreover, the inertness and inability of B-MLUS cells in comparison to normal B- and B-CLL cells to respond to powerful activation signals might indicate an intrinsic defect of B-MLUS cells in the signal transduction leading to a block of mitosis and a benign course of the disease.

Defective T lymphocyte function in nonthymectomized patients with myasthenia gravis

In vitro functional properties of peripheral blood mononuclear cells were evaluated in 29 patients with myasthenia gravis and in 11 healthy controls. Spontaneous cell proliferation was higher in patients than in controls. The production of interleukin-2 and interferon-gamma and the proliferative response to different mitogens were reduced in the patients. A positive correlation was found between the production of interleukin-2 and interferon-gamma. These defects in T cell function were the most pronounced in nonthymectomized patients. Patients with severe disease had a higher percentage of cells bearing the interleukin-2 receptor and a higher spontaneous production of tumor necrosis factor alpha in cell culture than in patients with mild disease. There was no difference between patients and controls in the level of soluble interleukin-2 receptor in cell culture supernatants or in sera. The results indicate a partially suppressed T cell function in myasthenia gravis. This defect was less pronounced in patients studied after thymectomy.

Anti-idiotypic antibodies in patients with monoclonal gammopathies: relation to the tumour load

The production of anti-idiotypic antibodies from Epstein-Barr virus transformed peripheral blood lymphocytes was analysed in 12 patients with multiple myeloma and monoclonal gammopathy of undetermined significance. A low anti-idiotype production was found in patients with advanced disease (multiple myeloma stage III), whereas the production was high in patients with multiple myeloma stage I and monoclonal gammopathy of undetermined significance (MGUS) (P less than 0.01). The study supports the existence of an immunological network response in patients with monoclonal gammopathies.

Effect of thyrotropin-releasing hormone on immune functions of peripheral blood mononuclear cells

The tripeptide thyrotropin-releasing hormone (TRH) works as a hypothalamic hormone, but is found also outside the brain in intrinsic nerve fibers of the gastrointestinal tract. There is evidence that TRH modulates the activity of immunocompetent cells, although there are only very few data on TRH-mediated immune effector functions. Since we could recently show that TRH inhibits monocyte activities we were also interested in other possible TRH modulated immune functions. Peripheral blood mononuclear cells (PBMC) from ten healthy subjects were cultured for 7 days and pulsed with 0.125 and 0.250 microgram/ml Pokeweed mitogen (PWM). 10(-12) to 10(-6) M TRH was added simultaneously with PWM. Lymphocyte proliferation [(3H]thymidine incorporation), interferon-gamma (IFN-gamma) activity (RIA) and immunoglobulin activities (IgG, IgM, IgA; ELISA) were determined in the supernatants. We could demonstrate a TRH-dependent decrease in PWM-pulsed IgG activity with significant (alpha = 0.05) values at 10(-8) and 10(-10) M (-29 +/- 6%/-16 +/- 3% for PWM 0.125 microgram/ml and -17 +/- 9%/-11 +/- 9% for PWM 0.250 microgram/ml). This inhibitory effect could be abolished by an anti-TRH antiserum. There was no TRH effect on IgM and IgA activities, IFN-gamma activity and lymphocyte proliferation compared with the PWM stimulated values alone. The described TRH effect on the polyclonal IgG response by PBMC gives further evidence for a functional link between the immune system and the endocrine system, although its underlying mechanism is not yet clear.

Effect of substance P on immunoglobulin and interferon-gamma secretion by cultured human duodenal mucosa

Recently, we have demonstrated a substance P (SP)-dependent modulation of in vitro IgM and interferon-gamma (IFN-gamma) secretion by human peripheral blood mononuclear cells, as well as lymphokine activities in supernatants of cultured duodenal mucosa. Therefore we investigated other local immunoregulatory effects of SP. Duodenal biopsies of 7 healthy subjects were cultured with Pokeweed mitogen (PWM, 1 microgram/ml) for 4 days at 37 degrees C in 1 ml medium each. SP was added in concentrations ranging from 10(-12)M to 10(-6)M on day 1. Fresh media with fresh PWM were added every day. IgG, IgM, IgA (ELISA) and IFN-gamma (RIA) were determined in the culture supernatants. Values were referred to 5 mg biopsy weight and expressed as % change in basal PWM pulsed secretion, or as units/ml. 10(-6) M and 10(-12) M SP increased secretion of all immunoglobulin isotypes. Compared to controls, 10(-6) M and 10(-12) M SP led to an increase in IgM secretion of up to 73 +/- 23% and 41 +/- 32% and to an increase in IgA secretion up to 96 +/- 35% and 25 +/- 33%, respectively (alpha = 0.02 for both isotypes at 10(-6) M). 10(-12) M to 10(-6) M SP led to a significant dose-dependent increase in IFN-gamma secretion from 7.08 +/- 1.65 up to 21.8 +/- 12.6 units/ml/5 mg. The maximum effect could be seen on culture days 3 and 4. We were able to demonstrate for the first time that SP stimulates PWM pulsed immunoglobulin and IFN-gamma secretion by human duodenal immunocompetent cells. These results support the hypothesis of local neuropeptidergic-immune interactions.

B lymphocyte function in multiple myeloma: analysis of T cell- and monocyte-dependent antibody production

T-cell and B-cell functions were studied in 35 patients with untreated multiple myeloma (MM) and in 16 patients with MM treated with prednisolone, melphalan and vincristine. The numbers of CD4+ T cells were normal in untreated MM patients, but markedly decreased in treated patients, whereas CD8+ cell numbers were normal in untreated and treated patients. Mitogen-induced as well as antigen-induced lymphocyte proliferative responses were reduced, but not further affected by treatment. The antigen-induced proliferative responses by lymphocytes of treated, but not of untreated patients, correlated positively to the proportions of CD4+ cells among MNC. Taken together, the findings suggest selective loss of CD4+ subpopulations during cytotoxic treatment. Pokeweed mitogen (PWM)-induced Ig production was generally low, but significantly reduced Ig production was only seen in experiments employing MM B cells and monocytes co-cultured with irradiated T-enriched cells. Irradiated MM T cells displayed normal helper function when co-cultured with normal B cells stimulated with PWM. MM B cells and monocytes cultured with irradiated normal T cells produced little Ig; however, MM monocytes were not suppressive. In 2 of 3 patients with either IgG-kappa or IgA-kappa myeloma, the numbers of PWM-stimulated B cells that produced kappa chains were somewhat higher than those found among normal MNC. The impaired ability of antibody production by B cells from untreated MM patients seems to relate to intrinsic B cell defect(s) rather than to abnormal regulation by T cells or monocytes. However, disturbances in the functions of CD4+ cells may be observed in treated MM.

Effect of interleukin-2 on the ex vivo growth of human myeloma cells

Short-term cultures containing bone marrow mononuclear cells from multiple myeloma patients secrete monoclonal immunoglobulin- and beta 2-microglobulin into the supernatant, which can be measured quantitatively in an enzyme-linked immunosorbant assay. In this system, the addition of interleukin-2 was shown to induce tumor cell regression in the cultures from 10 out of 14 multiple myeloma patients in a dose-dependent manner. Marker analyses of culture cell populations indicate that OKT3 antibody or interleukin-2 did not directly act on the malignant clone but augmented autologous T lymphocytes, which were responsible for the regression of tumor cells in the cultures.

Phenotypical and functional characterization of the idiotype-positive blood B cells in multiple myeloma

In this study the idiotype-positive B cells of one patient with smouldering multiple myeloma (IgG kappa) and of one patient with multiple myeloma (IgG lambda) were analysed phenotypically and functionally. As regards the expression of B cell-associated differentiation antigens and size distribution, the idiotype-positive B cells resembled normal IgG-bearing blood B cells. In functional studies the lymphocytes were cultured in vitro with Staphylococcus aureus, pokeweed mitogen, T-cell factors, or combinations of these. After culture, proliferation and differentiation of the idiotype-positive B cells were measured by autoradiography, an idiotype-specific ELISA, and a spot ELISA. The results show that idiotype-positive B cells of both patients are able to proliferate after stimulation in vitro. In contrast to their normal counterparts, however, almost no increase in the amount of secreted idiotype IgG could be induced. This suggests that the idiotype-positive blood B cells have lost some of their ability to respond to exogenous stimuli.

Cellular production of antibodies related to the acetylcholine receptor in myasthenia gravis: correlation with clinical stage

Spontaneous and pokeweed mitogen-induced production of specific autoantibodies were studied in cultures of peripheral blood mononuclear cells from patients with different clinical stages of myasthenia gravis. Receptor antibody-related idiotypes and anti-idiotypic antibodies were defined by binding to mouse monoclonal anti-idiotypic and anti-receptor antibodies, respectively. Patients with severe disease had a more complete spectrum of idiotypes in serum, and cells from such patients spontaneously produced more antibody species and higher concentration of both idiotypes and anti-idiotypes than patients with mild disease. The frequencies of antibody specificities in tissue culture supernatants more closely reflected disease activity than those in serum. Tissue culture for the study of different species of autoantibodies has proved to be a useful tool for monitoring the disease and the effects of treatment.

Chemiluminescence response of human B-cell lines

Epstein-Barr virus (EBV)-transformed human B lymphoblastoid cells share certain properties with monocytes: they are capable of presenting protein antigens to antigen-specific T-lymphocytes and of releasing an Interleukin 1-like factor. It was our interest to study whether transformed B-cells resemble monocytes by generating toxic oxygen radicals. Human B-cell lines were developed from human peripheral blood lymphocytes by EBV-transformation. The induction of the respiratory burst in the B-cells was assessed by chemiluminescence (CL) in the presence of lucigenin. B-cells were stimulated with phorbol-myristate-acetate (PMA), zymosan particles, the chemotactic peptide f-met-phe, the complement split product C5a and with a recently described granulocyte activating cytokine (GRAM). Stimulation with PMA elicited a distinct CL-response in the tested B-cell lines. The CL-signal was significantly reduced by superoxide dismutase, but not by D-mannitol and catalase. No significant response to any of the other stimuli was detected. Furthermore, none of the stimuli induced a luminol-enhanced CL signal, which, in contrast to lucigenin, is dependent on the presence of peroxidase. Our results indicate that EBV infected B-cells were able to generate significant amounts of reactive oxygen species, particularly superoxide. It appears that virus transformation uncovers genetic information which is usually not expressed in non-transformed B-cells.

Acetylcholine receptor antibodies and anti-idiotypic antibodies produced in blood lymphocyte cultures from patients with myasthenia gravis

The production of acetylcholine receptor antibody idiotypes and of antibodies directed against receptor antibody idiotopes were studied in cultures of blood mononuclear cells from 11 patients with myasthenia gravis and 11 healthy donors. The antibody specificities were defined by their reaction with monoclonal anti-receptor and anti-idiotypic antibodies. Cells from eight patients but no controls produced both kinds of antibodies. These antibodies were less frequently found in patients' sera. In no patient were antibody specificities present in serum not detected in cell cultures. It is concluded that the B-cell repertoire of specific autoantibodies is more completely disclosed by analysis of blood cell cultures than by serum antibody determinations. The results suggest an idiotype-anti-idiotype regulation of anti-acetylcholine receptor autoimmunity in myasthenia gravis.

Cytostatic drug sensitivity test for human multiple myeloma, measuring monoclonal immunoglobulin produced by bone marrow cells in vitro

An in vitro cytostatic drug sensitivity test for human multiple myeloma has been developed, predicting differences in sensitivity of the individual tumor to various anticancer drugs. Bone marrow preparations containing the tumor cells were incubated with cytostatic drugs and cultured for 10 days. Using an enzyme-linked immunosorbent assay we measured tumor products--monoclonal immunoglobulin and beta 2-microglobulin--in the culture supernatants. The reduction of these products in vitro due to the drugs administered was compared with the patients' further clinical course during treatment with different standard cytostatic drug regimens. We found a predictive value of more than 80% for this easily performed test.

Application of a serum-free medium in the growth and differentiation of human peripheral blood lymphocytes

To eliminate variability due to nonspecific stimulation or inhibition by different lots of fetal bovine serum, the activation of human peripheral blood mononuclear cells in a modification of Iscove's medium (medium C-IMDM) was compared with the routinely used Roswell Park Memorial Institute (RPMI)-1640 medium containing 15% fetal bovine serum. Stimulation of peripheral blood mononuclear cells was enhanced and occurred at lower mitogen concentrations in C-IMDM compared with cells grown in RPMI-1640 supplemented with fetal bovine serum. Maximum incorporation of [3H]thymidine following stimulation by concanavalin A, phytohemagglutinin, and pokeweed mitogen was more than twice the peak values obtained in RPMI-1640 supplemented with fetal bovine serum. Concentrations of concanavalin A and phytohemagglutinin required for maximum stimulation were 0.5 and 15 micrograms/ml, and 0.3 and 1.0 micrograms/ml . 5 X 10(5) cells in C-IMDM and RPMI-1640, respectively. Cells grown in C-IMDM responded to lower concentrations of pokeweed mitogen and optimal growth in the serum-free medium required 0.4 micrograms/ml . 5 X 10(5) cells. The stimulation of immunoglobulin-producing cells in C-IMDM was enhanced and occurred at lower concentrations of pokeweed mitogen. Less variability of growth (i.e., incorporation of [3H]thymidine) and immunoglobulin synthesis occurred in peripheral blood mononuclear cells cultured in different preparations of C-IMDM than that reported for cells cultured in RPMI-1640 supplemented with different lots or batches of fetal bovine serum. These data suggest that C-IMDM may be an alternative to media supplemented with fetal bovine serum.

Treatment of adult patients with idiopathic thrombocytopenic purpura with intravenous immunoglobulin: effects on circulating T cell subsets and PWM-induced antibody synthesis in vitro

Eight adult patients with idiopathic thrombocytopenic purpura (ITP) were given two 5-d courses of intermediate (250 mg/kg body weight/d) to high dose (400 mg/kg body weight/d) intravenous infusions of human plasmin-cleaved Ig, at 15-30 d intervals. Three patients also were given single booster infusions (400 mg/kg body weight for 1 d) of a different preparation, S-sulfonated Ig. As expected, significant though transient rises in the platelet count were consistently observed in all patients. The mean platelet count increase was 95 600/mm3 after the first course, and 143 500/mm3 after the second course. Similar effects of lower magnitude were obtained several times in the patients given single booster doses. In three patients, platelet-bound IgG levels were decreased in association with Ig therapy. Phenotypic analysis of T cell subsets before starting Ig therapy and at the end of the second high dose course of intravenous Ig treatment revealed significant reductions in the proportion of T4+ lymphocytes in five patients and relative increases in the percentage of T8+ cells after therapy. As the overall proportion of T3+ cells remained unchanged, the T4+/T8+ ratio was therefore decreased. The total number of circulating lymphocytes was also decreased following therapy. In addition, PWM-driven Ig biosynthesis in vitro was significantly impaired after therapy in most patients, the capacity to synthesize IgG being mainly affected. It is concluded that, in addition to the reported transient blockade of the reticuloendothelial system, non-specific suppression of polyclonal Ig biosynthesis induced by the high dose Ig infusions also contributes to the net increase in platelet count.

Serum immunoglobulin-lipid complexes in plasma cell dyscrasia

Immunoglobulin-lipid complexes (SILC) are found in the serum of all patients with monoclonal gammopathy. Fractionation by density gradient ultracentrifugation, Sephadex G-200 chromatography and Sepharose protein A affinity, followed by extensive immunoassaying for immunoglobulins and lipoproteins, does not confirm the accepted assumption that SILC are immune complexes between monoclonal immunoglobulins and lipoproteins. Lipid extraction of monoclonal fractions isolated on protein A columns followed by thin-layer chromatography shows a lipid pattern characteristic of the one found in cellular membranes. It is proposed that SILC are hydrophobic complexes between immunoglobulins and lipids, as described in membranes of B lymphocytes.

Serum antibodies against common antigens of bacterial lipopolysaccharides in healthy adults and in patients with multiple myeloma

The incidence of infections caused by gram-negative bacteria is increased in patients with multiple myeloma due to secondary humoral immunodeficiency. In order to diagnose patients with increased susceptibility to gram-negative infections, serum antibodies against common determinants of lipopolysaccharides (lipid A and core-polysaccharide) were determined by a rapid enzyme-linked immunosorbent assay (ELISA). It was possible to define a group of patients at high risk of contracting gram-negative infections using this test. Intravenous IgG preparations used as a substitute were shown to contain antibodies against these common antigens. However, it is suggested that the clinically recognized efficacy of these preparations could be due to their containing anti-LPS antibodies.

In vitro immunoglobulin production by peripheral blood mononuclear cells from multiple myeloma patients and patients with benign monoclonal gammopathy. Regulation by cell subsets

Peripheral blood mononuclear cells (PBM) from four patients with IgG myeloma and four patients with benign monoclonal gammopathy (BMG) were stimulated with pokeweed mitogen (PWM), and the in vitro immunoglobulin production over 7 days was measured with an enzyme-linked immunosorbent assay. All myeloma patients were sufficiently treated with cytostatic drugs. Their PBM did not produce monoclonal Ig in vitro, as opposed to PBM from two patients with BMG. Unseparated PBM from myeloma patients produced smaller amounts of polyclonal Ig than unseparated cells from normal donors. However, macrophage-depleted PBM from myeloma patients produced amounts of Ig comparable to those of normal donors when autologous or allogeneic adherent cells were returned in defined numbers. T cells from three of the four myeloma patients could provide help for the Ig production by B cells from healthy donors. These results indicate that functionally normal polyclonal B cells circulate in the blood of myeloma patients. The circulating T-cell population also has no obvious defect. In contrast, blood macrophages seemed to be altered with respect to their regulating function for polyclonal Ig production. The results obtained by using cell populations from patients with BMG did not differ from those of healthy people.

Imbalances of T-cell subsets in monoclonal gammopathies

In 42 patients with untreated or treated multiple myeloma (MM) or benign monoclonal gammopathy (BMG) the lymphocytes and T lymphocyte subsets were determined by monoclonal antibodies and other surface markers. In untreated MM, the T cells (1077/microliters vs 1439/microliters, P less than 0.01) and especially the OKT4+ lymphocytes (700/microliters vs 950/microliters, P less than 0.05) were significantly reduced compared with a control group. The OKT8+ cells were slightly but not significantly decreased. In previously treated MM, the loss of T cells was more pronounced than in the untreated group and was primarily caused by a further reduction of OKT4+ cells. Patients with BMG revealed decreased OKT8+ lymphocytes (304/microliters vs 502/microliters, P less than 0.001), whereas the OKT4+ cells were within the normal range. Therefore, the OKT4/OKT8 ratio was significantly elevated compared with that in untreated MM patients and normal controls (3.31 vs 2.06 vs 2.13; P less than 0.005). To sum up, in MM the results revealed a reduction of T cells, mainly of OKT4+ cells, which is intensified by chemotherapy and persists even after a long therapy-free interval. The different findings of T cell subsets in BMG and MM may be a helpful criterion to differentiate between BMG and MM.

Analysis of T-cell cultures and clones from a patient with classic rheumatoid arthritis--evidence for the existence of autoreactive T-cell clones in blood and synovial fluid

Using lectin-free IL-2 as the only initial stimulus, bulk cultures and T-cell clones were established from synovial fluid (SFL) and peripheral blood lymphocytes (PBL) of a patient with rheumatoid arthritis (RA). The cloning efficiency of growing bulk cultures was 3%-4% as evaluated by Poisson statistics and was not enhanced by the addition of autologous synovial fluid or serum. The majority of the cloned T cells expressed the OKT8+ phenotype; several clones were OKT4+ and one clone expressed OKT8+ and OKT4+ antigens. None of the cloned T cells exhibited high NK or lectin-dependent cytotoxicity, although bulk cultures had high NK activity. In primed lymphocyte typing responses, bulk cultures and two T-cell clones established from rheumatoid SFL and PBL showed consistent autoreactivity, which we have never before observed with MLC-derived bulk cultures and T cell clones. One of the autoreactive rheumatoid T-cell clones (B25) was found to provide strong helper activity to autologous B cells in the absence of mitogen. Attempts to reveal reactivity of RA-derived T-cell clones to microbial antigens have so far only been successful with Mycoplasma pneumoniae preparations. Careful analysis of this reactivity revealed, however, that Mycoplasma pneumoniae induces a stimulator cell-dependent mitogenic effect rather than an antigen-specific MHC-restricted T-cell proliferation.

High dose intravenous IgG reduces platelet associated immunoglobulins and complement in idiopathic thrombocytopenic purpura

4 children with idiopathic thrombocytopenic purpura were treated with high dose i.v. IgG. Platelet associated immunoproteins were determined with an Elisa technique. Platelet counts increased in all patients, while simultaneously platelet associated IgG, IgA, IgM, C3 and C4 decreased. Serum antiplatelet antibody increased during treatment suggesting that administration of high doses of IgG interferes with the binding of antiplatelet antibody.

Virus-specific antibody activity of different subclasses of immunoglobulins G and A in cytomegalovirus infections

Healthy donors and patients with primary or reactivated cytomegalovirus infections were examined for antiviral antibodies of the immunoglobulin G (IgG) and IgA subclasses. For this purpose, monoclonal antibodies against the four IgG and the two IgA subclasses were used in enzyme-linked immunosorbent assays with cytomegalovirus antigen. IgG1 and IgG3 were the principal anti-cytomegalovirus subclasses in serum samples from healthy donors and patients. IgG1 was higher in reactivated than in primary disease. Cytomegalovirus-specific IgG2 was detected only in serum samples with high total cytomegalovirus IgG. A few patients with high total serum IgG4 also had cytomegalovirus-specific IgG4 antibodies. During convalescence, there was no significant increase in total IgG of any subclass. Both IgA1 and IgA2 antibodies with cytomegalovirus specificity were detected in patients who had cytomegalovirus antibodies of the IgA class.

Physiological variation of blood lymphocyte reactivity: T-cell subsets, immunoglobulin production, and mixed-lymphocyte reactivity

Highly purified blood lymphocytes from healthy individuals were obtained from samples collected before and after a standardized bicycle ergometer test. In accordance with previous findings physical work resulted in a marked increase of circulating lymphocytes, with a proportionate decrease of T lymphocytes and increase of non-T lymphocytes including B cells. The decrease of T lymphocytes was accounted for by a reduction of cells reactive with the monoclonal OKT4 serum (helper/inducer), whereas the proportion of OKT8-positive cells (suppressor/cytotoxic) remained unchanged. The lymphocyte production of IgG, IgM, and IgA after 7 days culture with pokeweed mitogen and the lymphocyte DNA synthesis after activation by allogeneic cells was reduced during work. It is concluded that nonspecific stress changes the composition of T-lymphocyte subsets with depression of T-cell stimulation and T-cell-dependent immunoglobulin production.

T cells in monoclonal gammopathies

Subpopulations of human T lymphocytes were analysed by monoclonal antibodies (OKT3, OKT4, OKT8) in healthy controls and in patients with multiple myeloma (MM), Waldenström's macroglobulinemia (WM) and benign monoclonal gammopathy (BMG). Lymphocytes forming rosettes with SRBC correlated well with T cells staining in indirect immunofluorescence by OKT3 monoclonal antibodies. The relative and absolute numbers of OKT4+ T cells were significantly lower in patients than in controls. Though, the percentage of OKT8+ T cells was increased in patients, the total OKT8+ cell counts were normal in all patient groups. The ratio between OKT4+ and OKT8+ lymphocytes was low in the groups of treated MM and of WM patients compared to controls (P less than 0.001). Moreover, the ratio was lower than the normal range in 27% of BMG and 38% of untreated MM patients. The imbalance between OKT4+ and OKT8+ T cells in untreated MM was more pronounced in clinical stage III patients than in stage I and II patients. The most pronounced changes were noted in treated MM patients. The significance of the altered T cell subsets in monoclonal gammopathies with regard to polyclonal and tumor B cell regulation remains to be established.

Monoclonal blood lymphocytes in benign monoclonal gammopathy and multiple myeloma in relation to clinical stage

20 patients with benign monoclonal gammopathy (BMG) have been studied for blood lymphocyte and subpopulations. 4 patients had slightly decreased T-lymphocyte values. Total B-lymphocytes were within the normal range. In 3 BMG patients an abnormal ratio between kappa- and lambda-bearing lymphocytes was detected indicating circulating monoclonal cells. 41 lymphoid cells using the kappa: lambda-ratio. 54% of the patients had monoclonal blood cells at diagnosis. the incidence and numbers of such cells increased with advanced clinical stage. Thus, it seems as if tumor volume is the main factor responsible for the appearance of monoclonal blood cells in multiple myeloma.