Monoclonal macroglobulinemia in NZB-NZW F1 mice

Early onset multiple myeloma in a patient with systemic lupus erythematosus: a case report and literature review

Patients with systemic lupus erythematosus (SLE) are at increased risk for various plasma cell dyscrasias, but the coexistence of SLE and multiple myeloma (MM) are rarely reported to date. Due to the rarity, the clinical features of MM associated with SLE have not been elucidated, and the pathogenesis under this association remains unclear. In this report, we investigate a 31-year-old woman with 5-year history of SLE, who is diagnosed as IgA λ-type MM with multiple lymph node involvement. We discuss the clinical features of MM in SLE by reviewing previous cases and possible mechanisms connecting the two conditions.

Genetic aspects of inherent B-cell abnormalities associated with SLE and B-cell malignancy: lessons from New Zealand mouse models

Genes that predispose to SLE are closely related to key events in pathogenesis of this disease. As much of the pathology can be attributed to high affinity autoantibodies and/or their immune complexes, some of the genes may exert effects in the process of emergence, escape from tolerance mechanisms, activation, clonal expansion, differentiation, class switching and affinity maturation of self-reactive B cells. A number of growth and differentiation factors and signaling molecules, including positive and negative regulators, are involved in this process. Genetic variations associated with functional deficits in some of such molecules can be involved in the susceptibility for SLE. As is the case with SLE, hereditary factors play significant roles in the pathogenesis of B cell chronic lymphocytic leukemia (B-CLL). Patients with B-CLL or their family members frequently have immunological abnormalities, including those associated with SLE. It is suggested that certain genetically determined regulatory abnormalities of B cells may be a crossroad between B-CLL and SLE. A thorough understanding of the genetic pathways in B cell abnormalities leading to either SLE or B-CLL is expected to shed light on their association. New Zealand mouse strains are pertinent laboratory models for these studies. Chromosomal locations of several major genetic loci for abnormal proliferation, differentiation and maturation of B cells and relevant candidate genes, located in close proximity to these intervals and potentially related to the SLE pathogenesis, have been identified in these mice. Further studies make for a wider knowledge and understanding of the pathogenesis of SLE and related B-cell malignancy.

The natural history of a lymphoproliferative disorder in aged NZB mice

The molecular lesions of human familial and common B-CLL remain unknown. As an approach to this problem, aged NZB mice with a B cell lymphoproliferative disorder were chosen as a murine model. Three groups of NZB mice (2 months, 6 months and > 18 months) for a total of nineteen were studied. A complete autopsy including a CBC was performed on each mouse. Spleen cells were immunophenotyped and cell cycle analysis was performed. Spleen weight, peritoneal cell counts and absolute lymphocytes counts were all elevated in the oldest group. All mice showed evidence of extramedulary hematopoiesis and the older group showed lymphocytic infiltrates in the lacrymal glands, kidneys, liver and lungs. Two of the seven aged mice had a malignant lymphoma. One was a marginal zone lymphoma and the other a lymphocytic lymphoma. Splenic immunophenotyping showed a loss of T cells with an increase in B cells as the mice age. Cell cycle analysis revealed hyperdiploidy in all of the aged mice with a decrease in the percentage G0G1 cells. This disease appears to involve an absolute lymphocytosis of the peritoneum and the peripheral blood compartment. This is associated with splenic aneuploidy. The infiltration of the spleen by malignant cells of varying morphology is a late event. The aged NZB mouse continues to be a model for human B-CLL.

Human CD5-positive B cells in lymphoid malignancy and connective tissue diseases

The current literature on human CD5-positive B cells (CD5 + B cells) has been analysed, with a special emphasis on non organ-specific auto-immune diseases. Malignant cells of most of the chronic lymphoid leukaemias of the B cell lineage express the CD5 molecule. Antibodies of the IgM class produced by leukaemic B cells are multispecific auto-antibodies. The CD5 + B cell subset may be expanded in non organ-specific autoimmune diseases, such as rheumatoid arthritis, primary Sjögren's syndrome, systemic lupus erythematosus. This holds true for various conditions, including organ-specific auto-immune diseases. Since auto-immune features are common in lymphoproliferative disorders, and the latter be a complication in non organ-specific auto-immune diseases, CD5 + B cells may represent an intermediary between these auto-immune diseases and B cell lymphoproliferations. Studies on the regulation of CD5 + B cell production and function are likely to shed light on the aetiology of, and pathogenetic mechanisms operating in the different disease states.

Major histocompatibility complex controls clonal proliferation of CD5+ B cells in H-2-congenic New Zealand mice: a model for B cell chronic lymphocytic leukemia and autoimmune disease

By employing H-2-congenic NZB, NZW and (NZB x NZW)F1 mice with either the homozygous H-2d/H-2d, H-2z/H-2z or heterozygous H-2d/H-2z haplotype, we found that in the spleen of all the congenic strains homozygous for H-2z, there were extremely high frequencies of CD5+ B cells. These cells eventually proliferated in an oligoclonal or even monoclonal fashion, and B cell-chronic lymphocytic leukemia (B-CLL) developed in some cases. Because this feature was not observed in H-2d/H-2d homozygotes or H-2d/H-2z heterozygotes, the high CD5+ B cell frequencies are apparently controlled by the homozygosity of a locus or cluster of loci closely linked to H-2z complex of NZW strain. As the CD5+ B cell frequencies in the peritoneal cavity did not differ among the H-2-congenic strains, the frequencies of these cells in the peritoneal cavity and in the spleen appear to be at least in part under separate control. Flow cytometry and Southern blot analyses using an immunoglobulin gene JH probe revealed that the H-2z/H-2z homozygotes, there was a propagation of distinct clonal populations between the spleen and the peritoneal cavity, a finding which suggested that in the major histocompatibility complex (MHC)-related microenvironments for CD5+ B cell propagation differ between the two compartments. All our findings taken together imply that certain different but related MHC haplotypes may predispose either to B-CLL or to autoimmune disease, in close relatives.

Further studies on the determinant recognized by naturally-occurring murine autoantibodies reacting with bromelain-treated erythrocytes

Radioimmunoassays (RIA) have confirmed previous studies that trimethylammonium (TMA) or its derivatives constitute part of the determinant recognized by naturally-occurring antibodies (NOA) with the ability to interact with bromelain-treated mouse erythrocytes (BrMRBC). Further studies on this determinant revealed its presence on erythrocytes from several species in addition to mice. In most cases (except in chickens) the determinant was cryptic and could be exposed only after proteolytic treatment of the erythrocytes. The determinant was also found on certain murine lymphoma cells. We also found that bromelain was not the only enzyme that could be used to expose the determinant. Papain, but not trypsin, was able to unmask the determinant on mouse erythrocytes. Rabbit antibodies directed against the idiotypes of four different monoclonal BrMRBC-binding NOA were prepared. Direct RIA assays and inhibition assays showed that the different monoclonal BrMRBC-binding NOA shared a common idiotype specific to such antibodies. The common idiotype was detected in the serum from several mouse strains and in wild mice.

Rheumatologic manifestations of cancer

A variety of musculoskeletal syndromes have been described in association with malignancy. The majority of such descriptions have dealt with the connective tissue disorder as a paraneoplastic syndrome, frequently the presenting feature of an otherwise occult malignancy. This may range from the well known syndrome of HOA, heralding lung cancer, to a lesser known association of pyogenic arthritis due to an unusual enteric pathogen, signaling colon cancer. Conversely, the connective tissue disorder may precede the malignancy, and by virtue of its pathophysiology or its therapy, foster the subsequent development of cancer. Awareness of these associations may lead to earlier cancer detection, and hence, potentially more effective therapy.

Monoclonal gammopathies in Japanese patients with Sjögren's syndrome

We report 10 Japanese patients with Sjögren's syndrome (SS) who developed monoclonal gammopathies (MG). One was of the IgG class, five of IgA, three of IgM, and one of IgG/IgM. The monoclonality of 7 of 10 M proteins was studied using antiidiotypic (Id) antibodies against M proteins. Four (three IgA and one IgM) of 10 M proteins had rheumatoid factor (RF) activity. Hemagglutination inhibition tests and enzyme-linked immunosorbent assays (ELISA) showed that the RF activity was inhibited by anti-Id antibodies in all four monoclonal RFs. In two patients examined, many cells infiltrating into the salivary glands were stained with anti-Id antibodies. Our review of 19 Japanese SS patients with MG revealed that the non-IgM class predominated (13/19). This contrasts with 19 reported non-Japanese SS patients, among whom 14 were IgM. In both Japanese and non-Japanese patients there was a higher incidence of MG in primary than in secondary SS. The difference in the dominant heavy-chain class may reflect a difference in the genetic factors affecting B cell differentiation in immunologically disordered states.

Systemic lupus erythematosus with paraproteinemia

Nine patients (2.2%) in a group of 415 who were followed in a longitudinal prospective study of systemic lupus erythematosus (SLE) were found to have various monoclonal (M) proteins in their blood (IgG [6 patients], IgA [2 patients], IgM [1 patient]). No other findings compatible with plasmacytic dyscrasia were found. Bence Jones proteinuria was absent. Bone marrow aspirates and skeletal radiographs did not reveal any associated features of malignancy. Four of the 9 patients were under the age of 50. From the point of view of the M components, 3 groups emerged: transient (2 patients), persistently stable (6 patients), and increasing serum concentrations (1 patient). Using current measures of disease status, no correlation was apparent between the presence, type, and concentration of the M protein and the clinical and laboratory variables of lupus activity. Thus, M proteins were found in 2% of our SLE patients, but their relationship to the polyclonal B cell activation seen in this disorder, or perhaps to therapeutic modalities used in its treatment, remains to be elucidated.

Neuropathological features of a lupus-like disorder in autoimmune mice

Neurological syndromes are prominent in systemic lupus erythematosus, but the neuropathological and mechanisms resulting in neurological dysfunction are unknown. We report a neuropathological study of the central nervous system in female NZB/W F1 mice, an animal model of systemic lupus erythematous. NZB/W mice were studied at 3, 5, 8, 12, and 14 months of age, and 36-month-old female C57B16N/NIA mice were studied as aged controls. A lymphoproliferative process was identified in the central nervous system of 39% of 8- to 12-month-old and all 14-month-old NZB/W mice. Infiltrates of lymphocytes and plasma cells were seen in subarachnoid, choroid plexus interstitial, and Virchow-Robin spaces. Lymphoid cells occasionally infiltrated brain parenchyma or accumulated as nodular masses. Concomitant visceral lymphoid infiltration was noted in 14-month-old mice. Dense deposits were seen ultrastructurally in the basal lamina of brain parenchymal capillaries of 14-month-old NZB/W mice. These dense deposits were similar in appearance to immune complexes described in glomerular basal lamina, and appeared concomitantly with an advanced lupus-like glomerulopathy. Similar deposits were not observed in choroid plexus. The possible relevance of these neuropathological changes to human central nervous system lupus is discussed.

Musculoskeletal syndromes associated with malignancy

Evidence has been presented supporting a causal relationship between malignancies and musculoskeletal syndromes. This discussion has dealt primarily with lesser known relationships, more common associations such as hypertrophic osteoarthropathy and dermatomyositis being reviewed elsewhere. The ones discussed herein closely mimic primary connective tissue diseases and offer an insight into the study of the pathogenesis of these primary diseases. In view of the natural history of malignant disease, the hope for such patients arises from the physicians early diagnosis and treatment of the underlying malignancy. Early diagnosis and treatment may in turn be entirely dependent on the physician's awareness of a musculoskeletal syndrome being the presenting feature of an otherwise occult neoplasm. Several connective tissue syndromes appear to predispose to the development of malignancy, and increasing evidence suggests that this development of malignancy may be further enhanced by immunosuppressive therapy.

Non-IgM monoclonal gammopathy in patients with Sjögren's syndrome

Two Japanese patients with Sjögren's syndrome with non-immunoglobulin M(IgM) class monoclonal gammopathy are described. The monoclonal IgA lambda detected in the serum and saliva was confirmed to possess rheumatoid factor activity in the first patient with a hypergammaglobulinemic purpura and hyperviscosity syndrome. Idiotype specificity was present on the surface membrane of peripheral blood lymphocytes as well as in the cytoplasm of infiltrating cells in the salivary glands. Common idiotypic specificity was found in four of 60 other patients who had rheumatoid factors. In the serum and saliva of the other patient, a monoclonal immunoglobulin G, kappa type (IgG kappa), was detected. Kappa type IgG was found in most of the infiltrating cells in the salivary glands and also in the saline extract from a resected submandibular gland. Our findings indicate that non-IgM class monoclonal gammopathy is also one of the complications of Sjögren's syndrome.

Differences in age and sex distributions among patients with non-Hodgkin's lymphoma

The records of a group of 337 adult patients with non-Hodgkin's lymphoma seen at the Stanford University Medical Center, Division of Oncology were examined for relationships between stage and histopathological classification and simple demographic characteristics. Patients with Stages I and II of disease and diffuse varieties of lymphoma were found to be younger than patients in other categories. An excess of male patients was noted particularly in younger patients with diffuse lymphoma and Stages I and II of disease. Male patients with Stages I and II disease were noted to be bimodally distributed with respect to age, with peak number of patients in the fourth and sixth decades. This was particularly apparent among patients with diffuse histiocytic lymphoma. The implications of these findings are discussed.

Suppressor cells and immunodeficiency in (NZB x NZW)F1 hybrid mice

Old (15-20 month) male (NZB x NZW)F1 (B/W) mice have severely impaired spleen cell reactivity to phytohemagglutinin (PHA), a mitogen which stimulates mainly T lymphocytes. Spleen cells from old mice markedly suppressed the PHA response of splenocytes from young (3-4 month) B/W males. Similar suppressor activity was not present in the spleens of old mice of four nonautoimmune strains. The suppressor activity of old B/W spleen cells was mediated by a nonphagocytic, radioresistant, mononuclear leukocyte. Although this cell was eluted in the "T lymphocyte" fraction of nylon wool colums, it was not sensitive to treatment with anti-Thy-1 antiserum and complement. Suppressor activity was lost after 18 h incubation at 37 degrees C in tissue culture medium. Supernatants of these overnight cultures had no suppressive effect on fresh young B/W spleen cells. Old B/W spleen cells suppressed PHA reactivity more than concanavalin A or lipopolysaccharide reactivity. Kinetic studies demonstrated an increasing suppression with time over 72 h of culture. This study demonstrate that the severely impaired PHA reactivity of old B/W mice is mediated, at least in part, by active suppression.

Quantitative estimations of five classes of immunoglobulin in inbred mouse strains

The age-dependent change of the levels of five classes of immunoglobulin in mouse serum were investigated. Between 3 and 12 months after birth, the major IgG subclass of BALB/c was IgG1, while that of C57BL/6 was IgG2b. This difference was the same in the sera from hyperimmunized or germ-free animals.

Transplantable lymphoma producing type K Bence-Jones protein in NZB mouse

Spontaneous lymphoma occurring in the retroperitoneum in a 13-month-old New Zealand Black female mouse, as transplantable to the same strain mice, was subjected to immunological studies by serial transplantation as subcutaneous solid tumor (66A) and bloody ascites tumor (66B). The transplanted tumor-bearing mice showed M component in the plasma, urine and ascites. It was confirmed as type K Bence-Jones protein. Speculations were made on the relation between abnormal immunity in NZB mice and lymphoma.

Independent appearance of anti-thymocyte and anti-RNA antibodies in NZB/NZW F1 mice

NZB and NZB/NZW (B/W) mice were studied for natural thymocytoxic autoantibody(NTA) and antibody to reovirus RNA by cytotoxicity and radioimmunoassay respectively.NZB mice developed NTA by 2-3 months of age. RNA antibodies appeared later if atall. NTA and anti-RNA were present in B/W mice starting at 4-5 months and increased in frequency with age. Either activity could appear first and could be present without the other. Thus, all four possible patterns of autoantibody occurrence were found. NTA and anti-RNA in 12-month B/W sera were separable by sucrose density gradient ultracentrifugation; NTA is a 19S IgM antibody whereas anti-RNA is 7S.

Acceleration of autoimmunity in NZB/NZW F1 mice by graft-versus-host disease

Chronic graft-versus-host (GVH) disease was induced in NZB/NZW F1 (B/W) hybrid female mice by the weekly injection of parental NZB spleen cells. Control mice received injections of syngeneic spleen cells only. The mice were assayed for antibodies to [3H]DNA and [3H]polyadenylic-polyuridylic acid by a cellulose ester filter radioimmunoassay, and for antibody to thymocytes by a cytotoxicity method. GVH disease accelerated the development of all three antibodies in B/W mice. In addition, sucrose density gradient ultracentrifugation of pooled sera suggested that an accelerated switch from 19S to 7S anti-DNA production may be an early effect of GVH. The mechanism of acceleration is discussed in terms of immunological and viral factors generated by the GVH reaction.

Protective and cellular immune responses to idiotypic determinants on cells from a spontaneous lymphoma of NZB-NZW F1 mice

A spontaneous lymphoma (141) producing monoclonal IgM is established in NZB/NZW F(1) (B/W) mice who spontaneously develop an autoimmune disease. Idiotypic determinants of 141 IgM are present on the lymphoma cell surface as shown by indirect immunofluorescence and specific cytotoxicity with rabbit anti-idiotypic antiserum. Fluorescence and cytotoxicity are inhibited by 141 IgM but not by 104E IgM, a monoclonal IgM produced by a BALB/c plasmacytoma. Immunization of B/W mice with 141 IgM before transplantation of lymphoma 141 confers protective immunity. No such protection occurs after immunization with 104E IgM or other unrelated proteins. Protected mice contain spleen cells cytotoxic for 141 lymphoma cells. This cytotoxicity is blocked by incubation of spleen cells with 141 IgM but not with 104E IgM. Moreover, splenic lymphocytes from protected mice are stimulated to synthesize DNA by 141 IgM but not by 104E IgM. These results suggest that specific cellular immune responses to idiotypic determinants may participate in the observed protection against challenge with the corresponding B-cell tumor.

Thymosin corrects the abnormal DNA synthetic response of NZB mouse thymocytes

New Zealand Black (NZB) mice develop after 16 weeks of age an autoimmune and lymphoproliferative disease which is a model for systemic lupus erythematosus and lymphoid malignancy in humans. At this age, the mice manifest a progressive decline in T lymphocyte (thymus-derived lymphocyte) functions and serum thymosin levels. Thymocytes from 8-week old NZB mice exhibit an abnormal DNA synthetic response when transplanted into lethally irradiated C57B1/6 recipients. DNA synthesis (measured as the incorporation of radioactively labeled 5-iodo-2'-deoxyuridine) is delayed in onset and still increasing 6 days after cell transfer. By contrast, 2-week old NZB thymocytes show a normal response which is rapid in onset and completed by day 6.NZB mice were injected with thymosin fraction 5 or with bovine serum albumin starting at 2 weeks of age. Thymocytes from 8-week old thymosin-treated mice showed a normal DNA synthetic response, whereas the albumin-treated controls showed the abnormal response expected at this age. The ability of thymosin to correct the DNA synthetic response was related to dose and duration of treatment. These results suggest that thymosin can induce a more normal state of thymocyte differentiation in NZB mice. If abnormal thymocyte differentiation is related to the subsequent emergence of autoimmunity and lymphoid malignancy, then continuous treatment with thymosin may have therapeutic potential. These experiments suggest that an endocrine disturbance may contribute to autoimmune and lymphoproliferative disease in NZB mice and possibly in humans.