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Porcine reproductive and respiratory syndrome virus (PRRSV) causes immune dysregulation during the Critical Window of Immunological Development. We hypothesize that thymocyte development is altered by infected thymic antigen presenting cells (TAPCs) in the fetal/neonatal thymus that interact with double-positive thymocytes causing an acute deficiency of T cells that produces "holes" in the T cell repertoire allowing for poor recognition of PRRSV and other neonatal pathogens. The deficiency may be the result of random elimination of PRRSV-specific T cells or the generation of T cells that accept PRRSV epitopes as self-antigens. Loss of helper T cells for virus neutralizing (VN) epitopes can result in the failure of selection for B cells in lymph node germinal centers capable of producing high affinity VN antibodies. Generation of cytotoxic and regulatory T cells may also be impaired. Similar to infections with LDV, LCMV, MCMV, HIV-1 and trypanosomes, the host responds to the deficiency of pathogen-specific T cells and perhaps regulatory T cells, by "last ditch" polyclonal B cell activation. In colostrum-deprived PRRSV-infected isolator piglets, this results in hypergammaglobulinemia, which we believe to be a "red herring" that detracts attention from the thymic atrophy story, but leads to our second independent hypothesis. Since hypergammaglobulinemia has not been reported in PRRSV-infected conventionally-reared piglets, we hypothesize that this is due to the down-regulatory effect of passive maternal IgG and cytokines in porcine colostrum, especially TGFβ which stimulates development of regulatory T cells (Tregs).

IgG4-related disease (IgG4-RD) is a novel systemic disease entity characterized by elevated serum IgG4 and tissue infiltration of IgG4-positive plasma cells accompanied by severe fibrosis. Although recent studies demonstrated that innate immune cells including monocytes and macrophages might promote local fibrosis and IgG4 production, the pathological mechanism remains unclear. In this study, we sought to identify the disease-associated genes, especially innate immune molecules. Gene expression was analyzed by DNA microarray in submandibular glands (SMGs) from patients with IgG4-RD (n = 5), chronic sialoadenitis (CS) (n = 3), and controls (n = 3). Differentially expressed genes (DEGs) were validated by real-time polymerase chain reaction (PCR) and immunohistochemical staining in IgG4-RD (n = 18), CS (n = 4), Sjögren syndrome (n = 11), and controls (n = 10). Gene expression patterns in the 3 groups were quite different from each other by the pvclust method and principal components analysis. In IgG4-RD, 1028 upregulated genes and 692 downregulated genes were identified as DEGs (P < 0.05). Gene Ontology (GO) term analysis indicated that the upregulated DEGs in IgG4-RD encoded proteins involved in T/B cell activation and chemotaxis. PCR validated significantly higher expression of macrophage receptor with collagenous structure (MARCO), a pattern-recognition receptor, in IgG4-RD compared with the other groups (P < 0.01). Immunohistochemical analysis confirmed that the expression pattern of MARCO was similar to that of the M2 macrophage marker CD163. MARCO was identified as a disease-associated molecule in IgG4-RD by DNA microarray. Moreover, M2 macrophages might contribute to the initiation of IgG4-RD via MARCO., Competing Interests: The authors have no conflicts of interest to disclose.

Autoantibody production and immune complex (IC) formation are frequently observed in autoimmune diseases associated with bone loss. However, it has been poorly understood whether ICs regulate bone metabolism directly. Here we show that the level of osteoclastogenesis is determined by the strength of FcRγ signalling, which is dependent on the relative expression of positive and negative FcγRs (FcγRI/III/IV and IIB, respectively) as well as the availability of their ligands, ICs. Under physiological conditions, unexpectedly, FcγRIII inhibits osteoclastogenesis by depriving other osteoclastogenic Ig-like receptors of FcRγ. Fcgr2b(-/-) mice lose bone upon the onset of a hypergammaglobulinemia or the administration of IgG1 ICs, which act mainly through FcγRIII. The IgG2 IC activates osteoclastogenesis by binding to FcγRI and FcγRIV, which is induced under inflammatory conditions. These results demonstrate a link between the adaptive immunity and bone, suggesting a regulatory role for ICs in bone resorption in general, and not only in inflammatory diseases.

Hyperimmunoglobulinemia is frequently observed in patients with chronic liver diseases. However, the exact mechanism underlying the high level of antibody formation is not fully understood. In our study, we provide evidence for the functional role of the liver and the stimulation of plasma cell proliferation in hyperimmunoglobulinemia. We collected sera from patients with chronic liver diseases, and the level of serum immunoglobulins in patients was examined; this was also investigated in animal models of liver cirrhosis and hepatocellular carcinoma. An end-to-side microsurgical portacaval shunt was used to mimic liver dysfunction in rats. We used portal vein serum and inferior vena cava serum to immunize healthy rats and mice in order to confirm the function of the healthy liver in disposing of antigens and endotoxins from the gut. For the analysis of the state of plasma cell activation, plasma cells from mice were stained with PE-conjugated anti-CD138 and FITC-conjugated anti-BrdU for flow cytometry analysis. Hyperimmunoglobulinemia was observed both in patients with chronic liver diseases and in related animal models, and high plasma LPS levels were also observed. There was a significant increase in the activation and proliferation of plasma cell in mice immunized with antigens or LPS-positive serum compared with controls that were immunized with antigens and LPS-negative serum. We confirmed that the healthy liver plays an important role in disposing of antigens and endotoxins derived from the gut. Hyperimmunoglobulinemia in chronic liver diseases mainly arises due to the collateral circulation secondary to portal hypertension, gut antigens and endotoxins that bypass the liver and reach the antibody-producing cells.

Aims: Urethral caruncle is a benign, polypoid urethral mass that occurs almost exclusively in postmenopausal women. Despite that these lesions are routinely managed with topical medications or excision, their pathogenesis is not well understood. We investigated the possibilities of autoimmune, viral and inflammatory myofibroblastic proliferations as possible aetiologies., Methods: In 38 patients with urethral caruncle, we utilised immunohistochemistry for immunoglobulin G (IgG) and IgG4 to assess for a potential autoimmune aetiology. Immunohistochemistry was performed in nine patients for Epstein-Barr virus, BK virus, human herpesvirus 8, human papillomavirus, adenovirus and anaplastic lymphoma kinase., Results: Four patients (11%) showed infiltrates of ≥50 IgG4-positive plasma cells per high power field, of which all showed an IgG4 to IgG ratio greater than 40%. A statistically significant difference (p<0.01) was detected in the mean number of IgG4-positive cells (14.73 per high power field) compared with control benign urethral specimens (mean, 1.19). One patient with increased counts below this threshold had rheumatoid arthritis; none had documented autoimmune pancreatitis or other known manifestations of systemic IgG4-related sclerosing disease. All lesions showed negative reactions for the viral and inflammatory myofibroblastic markers., Conclusions: Urethral caruncle is a benign inflammatory and fibrous polypoid urethral mass of unclear aetiology. It appears unrelated to viral infection and lacks the abnormal expression of anaplastic lymphoma kinase protein, as seen in inflammatory myofibroblastic tumours. Increased numbers of IgG4-positive plasma cells in a subset of lesions raise the possibility that some cases may be related to the autoimmune phenomena of IgG4-associated disease.

Objective: To detect cell frequency and surface markers of peripheral blood CD4⁺;CXCR5⁺;follicular helper T cells (Tfh cells) and analyze the correlation between CD4⁺;CXCR5⁺;Tfh cells and hyperglobulinemia of patients with chronic hepatitis B., Methods: We collected blood samples of 20 HBV infected patients with hyperglobulinemia, 10 chronic HBV infected patients and 10 health volunteers and isolated plasma and peripheral blood mononuclear cells (PBMCs). The percentage of CD4⁺;CXCR5⁺;Tfh cells and the expressions of PD-1, ICOS and CD40L on CD4⁺;CXCR5⁺;Tfh cells were detected by flow cytometry. The levels of CXCL13, IFN-γ and IL-21 in plasma were measured by ELISA., Results: Compared with the percentage of CD4⁺;CXCR5⁺;Tfh cells in chronic HBV infected patients (11.9 ± 3.9) and health controls (6.8 ± 3.9), it was higher in HBV infected patients with hyperglobulinemia (22.6 ± 4.7, P<0.05). And in the hyperglobulinemia patients, the expressions of PD-1 and CD40L on CD4⁺;CXCR5⁺;Tfh cells and the levels of CXCL13 and IL-21 in plasma increased, whereas the level of IFN-γ significantly declined (P<0.05)., Conclusion: The results suggest that CD4⁺;CXCR5⁺;Tfh cells may participate in the pathogenesis of hyperglobulinemia during HBV infection.

In this study, we investigate the hypothesis that IgG4-related autoimmune reaction is involved in the formation of inflammatory aortic aneurysms (IAA). We obtained 23 cases of IAA and 11 cases of atherosclerotic aortic aneurysms (AAA) as control group. We evaluated the expression of IgG4 in both IAA study cases and AAA control cases. In addition, immunohistochemical expression of C-Kit, CD21, CD34, S-100 protein, SMA, vimentin, p53, beta-catenin, and ALK-1, and EBV-LMP1 expression by in situ hybridization were performed only in IAA cases. Of the 23 patients, 20 were males and 3 were females (M: F ratio 6.7:1); age ranged from 43 to 81 years (average 64.3 years). Histologically, all 23 cases of IAA formed a mass that displayed inflammatory myofibroblastic tumor-like features. All lesions stained strongly and diffusely for vimentin and SMA (100%); 17 stained strongly and focally for CD34 (74%); and all were negative for C-Kit, CD21, S-100 protein, p53, beta-catenin, EBV-LMP1, and ALK-1. The numbers of infiltrating IgG4-positive plasma cells in IAA cases exceed that of AAA cases. Score 3 (>50 plasma cells/one 40X field) of IgG4-positive plasma cells was only seen in IAA cases (13/23, 57%), whereas none of the 11 cases of AAA showed score 3 IgG4-positive plasma cells (P=0.0018, Fischer's exact test). Our findings suggest that IAA may be an aortic manifestation of the IgG4-related sclerosing disease. The high number of positive plasma cells, >50 plasma cells/one 40X field is more specific for the IAA than for AAA; however, lesser number can be seen in both IAA and AAA patients.

Having the characteristic features of elevated serum IgG4 levels and prominent infiltration of IgG4-positive plasma cells with fibrosis in lesions, Mikulicz's disease (MD) has been recognized as an IgG4-related disease (IgG4-RD). Although incidence of autoimmune pancreatitis (AIP), one of the organ characteristics of IgG4-RD, has been internationally reported, there are only a few such reports of IgG4-related MD. The limited number of reports might be attributable to the low recognition of IgG4-related MD as a clinical entity as well as its misdiagnosis as Sjögren's syndrome (SS). Thus, we compared several clinical features of MD with SS to improve proper clinical diagnosis of MD in the clinical setting. A total of 70 SS and 70 MD cases evaluated at Sapporo Medical University Hospital were retrospectively analyzed. In SS patients, sicca symptoms were the most frequent (87%), followed by articular symptoms (23%), while lacrimal and salivary gland swelling were a rare (10%) and transient manifestation. In contrast, lacrimal or salivary gland swelling was observed in all patients with MD. Although nearly 60% of MD patients complained of sicca syndrome, skin rash and arthralgia were rare symptoms. Hypergammaglobulinemia was recognized in both SS and MD patients, but the occurrence of autoantibodies in patients with IgG4-related MD was low. Extraglandular organ involvement, often involving the retroperitoneum, pancreas, kidney and lung, was often discovered at the time of IgG4-related MD diagnosis. Although corticosteroid therapy tended to delay the hypofunction of salivary gland in SS patients, recovery of decreased function of salivary glands were observed in IgG4-related MD patients. These results suggest the beneficial effect of aggressive corticosteroid intervention in patients with IgG4-related MD. Although SS and MD are both chronic inflammatory diseases affecting the lacrimal and salivary glands, their clinical features and corticosteroid responsiveness are different. Thus, differential diagnosis of these conditions is warranted., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objective: To investigate the clinical and laboratory characteristics of tumor like Sjögren's syndrome (TLSS) patients and non-tumor like Sjögren's syndrome (NTLSS) and the incidence of lymphoma in patients of Sjögren's syndrome (SS)., Methods: A retrospective analysis was carried out in 199 primary SS (including TLSS) patients who were recruited in Peking University School and Hospital of Stomatology from 1998 to 2010. Clinical and laboratory information were collected. The patients were divided into two groups: TLSS (n = 25) and NTLSS (n = 174). Clinical and laboratory characteristics were compared between these two groups by a statistical analysis., Results: Of the 25 TLSS patients, 23 had enlargements of parotid glands and 2 had enlargements of submandibular glands. There were significant differences of salivary scintigraphy appearance (P = 0.018), hypergammaglobulinemia (P = 0.014), rheumatoid factor positive rate (P = 0.001), formation of the ectopic germinal centers (P = 0.014), double positive rate of anti-SSA antibody and anti-SSB antibody (P < 0.001) between the TLSS and NTLSS patients. Among the 25 TLSS patients, 3 developed lymphomas, accounting for 1.5% (3/199) of the total 199 patients and 12% (3/25) of the TLSS patients. Lymphoma subtypes included one diffused large B-cell lymphoma and two mucosa-associated lymphoid tissue lymphoma. There was no lymphoma detected in NTLSS patients., Conclusions: There are clinical and laboratory differences between TLSS and NTLSS patients, with a more tendency to develop lymphomas in TLSS patients.

Immunoglobulin (Ig) G4-related disease is a recently confirmed clinical entity with several unique clinicopathological features. Here we report a case of rheumatoid lymphadenopathy mimicking IgG4-related disease. The patient was a 63-year-old woman who had been treated for rheumatoid arthritis (RA) for six years. The patient noted cervical lymphadenopathy. Upon radiological examination, systemic lymphadenopathy was detected, and enlarged right brachial lymph node biopsy was performed. Histologically, the lymph node showed marked follicular hyperplasia and interfollicular plasmacytosis without eosinophil infiltration. Although the histological findings were compatible with rheumatoid lymphadenopathy, numerous plasma cells were IgG4(+) (IgG4(+)/IgG(+) plasma cell ratio > 50%). However, laboratory findings revealed elevation of C-reactive protein level, polyclonal hyper-γ-globulinemia, anemia, and hypoalbuminemia. These findings were compatible with hyper-interleukin (IL)-6 syndrome, namely, RA. It is known that hyper-IL-6 syndromes, such as multicentric Castleman's disease, RA, and other autoimmune diseases, fulfill the histological diagnostic criteria for IgG4-related disease. Therefore, hyper-IL-6 syndromes and IgG4-related disease cannot be differentially diagnosed by immunohistochemical staining alone. In conclusion, rheumatoid lymphadenopathy sometimes occurs with abundant IgG4(+) plasma cells, which is required for the differential diagnosis of IgG4-related disease.

Multiple myeloma (MM) is a currently incurable neoplasm of terminally differentiated B cells. The translocation and/or overexpression of c-MAF have been observed in human MM. Although c-MAF might function as an oncogene in human MM, there has been no report thus far describing the direct induction of MM by c-MAF overexpression in vivo. In this study, we have generated transgenic (TG) mice that express c-Maf specifically in the B-cell compartment. Aged c-Maf TG mice developed B-cell lymphomas with some clinical features that resembled those of MM, namely, plasma cell expansion and hyperglobulinemia. Quantitative RT-PCR analysis demonstrated that Ccnd2 and Itgb7, which are known target genes of c-Maf, were highly expressed in the lymphoma cells. This novel TG mouse model of the human MM t(14;16)(q32;q23) chromosomal translocation should serve to provide new insight into the role of c-MAF in tumorigenesis., (© 2011 AACR.)

Objective: A proliferation-inducing ligand (APRIL) is a new member of the tumour necrosis factor family which is intimately connected to the regulation of cellular pathways. The aim of this study was to assess serum concentrations of APRIL in systemic sclerosis patients, and to correlate them with the main clinical and serological features of the disease., Methods: Sera from 35 patients with systemic sclerosis, 25 had limited cutaneous and 10 had diffuse cutaneous subtypes, and 35 normal healthy subjects were assayed for APRIL by Enzyme Linked Immunosorbant Assay. Demographic, clinical, autoantibodies and serological data were prospectively assessed., Results: Serum APRIL concentrations were higher in patients with systemic sclerosis and in both its subtypes compared to the healthy controls (p<0.0001 in all). Patients with elevated APRIL levels had significantly higher incidences of myositis than those with normal levels (p=0.04). We did not find significant differences in other organ involvement prevalence between systemic sclerosis patients with elevated vs. normal APRIL levels. In addition, the frequencies of autoantibodies (i.e., anti-topoisomerase I, anti-centromere) were comparable between both groups. Serum APRIL levels were correlated with serum γ-globulins concentrations (r=0.404, p=0.016) but not with C-reactive protein, skin score, nor pulmonary functions. Serum APRIL was also correlated with creatine kinase levels only in systemic sclerosis patients with myositis (r=0.786, p=0.02)., Conclusion: Our preliminary results suggest increased serum APRIL levels in systemic sclerosis patients, particularly in those associated with myositis and hypergammaglobinemia. To confirm our results, we propose that larger scale, multicentre studies with longer evaluation periods are needed., (Copyright © 2010 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.)

Renal dysfunction is often seen in patients with plasma cell dyscrasias. The abnormal light and heavy chains that are produced by the neoplastic plasma cells in these patients are responsible for the renal abnormalities that occur. The renal manifestations are heterogeneous and include alterations in all three renal compartments; sometimes more than one compartment is affected in a given case. It must be demonstrated that the renal abnormalities are directly related to the underlying plasma cell dyscrasia to make a definitive diagnosis of an associated lesion. Therefore, it becomes crucial to link the renal findings with the circulating nephrotoxic light or heavy chains. Immunofluorescence is very helpful and diagnostic in the majority of the cases, as it can localize the light or heavy chains to the various renal compartments showing alterations, and frequently confirm monoclonality. However, the antibodies that are used routinely do not necessarily label the abnormal light and heavy chains; the corollary of this is that a negative immunofluorescence workup does not rule out a light- or heavy-chain-related renal disorder. Electron microscopy is also important as it can depict crucial morphologic correlates to provide unique evidence or to simply confirm and clarify diagnostic findings. Ultrastructural immunolabeling combines the information obtained from immunofluorescence and electron microscopy by highlighting specific structures associated with the deposition of the pathogenic monotypical light and heavy chains.

Fas ligand (FasL), an apoptosis-inducing member of the TNF cytokine family, and its receptor Fas are critical for the shutdown of chronic immune responses and prevention of autoimmunity. Accordingly, mutations in their genes cause severe lymphadenopathy and autoimmune disease in mice and humans. FasL function is regulated by deposition in the plasma membrane and metalloprotease-mediated shedding. Here we generated gene-targeted mice that selectively lack either secreted FasL (sFasL) or membrane-bound FasL (mFasL) to resolve which of these forms is required for cell killing and to explore their hypothesized non-apoptotic activities. Mice lacking sFasL (FasL(Deltas/Deltas)) appeared normal and their T cells readily killed target cells, whereas T cells lacking mFasL (FasL(Deltam/Deltam)) could not kill cells through Fas activation. FasL(Deltam/Deltam) mice developed lymphadenopathy and hyper-gammaglobulinaemia, similar to FasL(gld/gld) mice, which express a mutant form of FasL that cannot bind Fas, but surprisingly, FasL(Deltam/Deltam) mice (on a C57BL/6 background) succumbed to systemic lupus erythematosus (SLE)-like autoimmune kidney destruction and histiocytic sarcoma, diseases that occur only rarely and much later in FasL(gld/gld) mice. These results demonstrate that mFasL is essential for cytotoxic activity and constitutes the guardian against lymphadenopathy, autoimmunity and cancer, whereas excess sFasL appears to promote autoimmunity and tumorigenesis through non-apoptotic activities.

Objective: B and T lymphocyte attenuator (BTLA), a coreceptor expressed on lymphocytes, was recently described as an inhibitory coreceptor that negatively regulates lymphocyte activation. The purpose of this study was to investigate the role of BTLA in the regulation of immune homeostasis and the pathogenesis of autoimmunity., Methods: We examined the levels of immunoglobulins and autoantibodies to nuclear antigens and the activation status of T cells in BTLA(-/-) mice. We also examined histopathologic changes in the organs of BTLA(-/-) mice., Results: We observed that BTLA(-/-) mice gradually developed hypergammaglobulinemia, antinuclear antibodies, anti-SSA antibodies, anti-double-stranded DNA antibodies, and an increased number of activated CD4+ T cells in the periphery with age. Lack of BTLA led to spontaneous development of autoimmune hepatitis-like disease characterized by an elevation in the level of transaminases, interface hepatitis, and spotty necrosis of the liver. BTLA(-/-) mice also showed inflammatory cell infiltration of multiple organs, including the salivary glands, lungs, and pancreas; these features are similar to those of Sjögren's syndrome, which is a frequent complication of autoimmune hepatitis. Furthermore, the survival rate of BTLA(-/-) mice was significantly reduced after the age of 7 months., Conclusion: Our results indicate that BTLA plays an important role in the maintenance of immune tolerance and the prevention of autoimmune diseases.

Regional lymph nodes of Küttner's tumor from 3 patients showed reactive follicular hyperplasia and prominent interfollicular plasmacytosis. The patients were 71-, 57-, and 73-year-old Japanese men. The polytypic nature of plasma cells was demonstrated by immunohistochemistry. There were numerous IgG-positive plasma cells with scattered IgA-positive or IgM-positive plasma cells. IgG4-positive cells comprised 25% to 40% of IgG-positive plasma cells. Prominent polyclonal hyperimmunoglobulinemia was demonstrated on laboratory test in 2 cases examined. An elevated serum IgG4 level (16%) was also demonstrated in 1 patient. The present 3 cases indicated that regional lymph node of Küttner's tumor may show reactive follicular hyperplasia and prominent interfollicular plasmacytosis and should be differentiated from various benign and malignant lymphoproliferative disorders including systemic rheumatic disease, plasma cell type of Castleman disease, and lymph node involvement of marginal B-cell lymphoma of the mucosa-associated lymphoid tissue type showing prominent plasma cell differentiation.

A large body of evidence has convincingly shown that Toll-like receptors are necessary sensors for infections with pathogens, but their activation was also suggested to generate autoimmunity. During experimental infections, the lack of these sensors or of their signaling molecules should lead to a deficient immune response. We found out that MyD88, the major adaptor of the Toll/interleukin-1 (Toll/IL-1) receptor signaling pathway, can actually act as a negative regulator of B-cell function in some settings. MyD88-deficient mice infected by Borrelia burgdorferi developed extreme hypergammaglobulinemia compared to wild-type animals, with high levels of immunoglobulin M (IgM) autoantibodies. In vivo, cell transfer experiments and cell blocking assays showed that this phenotype was not linked to the absence of MyD88 in B cells but rather to CD4 T-cell and likely dendritic cell dysfunctions leading to a Th1-to-Th2 cytokine switch. In addition, our results suggest a relative defect in the Ig class switch recombination process, since MyD88 knockout mice developed mostly IgM antibodies. Collectively, these data emphasize the complex role of the Toll/IL-1 receptor pathway in tuning the immune response against infection and avoiding autoimmunity.

We report on pulmonary lesions seen in five cases of idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia (IPL). This group of five patients consisted of two Japanese men (age: 33 and 45 years), and three Japanese women (age: 25, 43, and 48 years). All five cases were detected incidentally on routine chest X-rays, and had multiple small nodular lesions in the bilateral lungs. These pulmonary lesions were the initial clinical presentation of IPL in three cases in which, at the onset of disease, no lymphadenopathy was detected. At the disease onset, all five cases showed prominent IPL. In three cases examined, serum interleukin-6 was elevated, and anti-human immunodeficiency type-1 antibody was negative in three cases. Clinically, autoimmune disease was suspected for all five cases, and the various autoantibodies were investigated. Although anti-Scl 70 antibody was positive in one case, this patient had no symptoms of systemic sclerosis. Pathologically, all five lesions were characterized by well-demarcated masses that consisted of abundant reactive germinal centers and a dense lymphoplasmacytic infiltrate in the interfollicular area with a variable degree of interfollicular fibrosis. The immunohistochemical study and polymerase chain reaction demonstrated the polytypic nature of the plasma cells and B-cells. IPL is rare in lymphoproliferative disorders. However, pulmonary involvement may frequently occur in IPL patients. Moreover, pulmonary involvement seems to represent the initial clinical manifestation of IPL. Therapeutically, it is important to discriminate between pulmonary involvement of IPL and pulmonary benign or malignant pulmonary lymphoplasmacytic proliferation, particularly marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue type.

Gene therapy using cDNA driven by an exogenous promoter is not suited for genetic disorders that require intrinsic expression of a transgene, such as hyperimmunoglobulin (Ig)M syndrome (HIGM), which is caused by mutations in the CD40L gene. The human artificial chromosome (HAC) vector has the potential to solve this problem, because it can be used to transfer large genomic fragments containing their own regulatory elements. In this study, we examined whether introduction of a genomic fragment of CD40L via the HAC vector permits intrinsic expression of the transgene and has an effect on immunoglobulin secretion. We constructed an HAC vector carrying the mouse CD40L genomic fragment (mCD40L-HAC) in Chinese hamster ovary (CHO) cells and transferred the mCD40L-HAC vector into a human CD4-positive active T-cell line (Jurkat) and a human myeloid cell line (U937) via microcell-mediated chromosome transfer (MMCT). The mCD40L-HAC vector permits mCD40L expression in human active T cells but not in human myeloid cells. The mCD40L-HAC also functions to stimulate mouse B cells derived from CD40L(-/-) mice, inducing secretion of IgG. This study may be an initial step toward the therapeutic application of HAC vectors for intrinsic expression of genes, a potential new direction for genome-based gene therapy.

Objective: Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autosomal-dominantly inherited autoinflammatory disorder caused by mutations in the TNFRSF1A gene. It is characterized by episodes of autoinflammation usually associated with fever, abdominal pain, myalgia, exanthema, arthralgia/arthritis, and ocular involvement. We undertook this study to investigate the prevalence of TRAPS in patients with multiple sclerosis (MS) who reported, in addition to their neurologic symptoms, at least 2 other symptoms compatible with TRAPS., Methods: Twenty-five unrelated MS patients were prospectively screened for TNFRSF1A mutations. In addition, blood samples from 365 unrelated MS patients and 407 unrelated Caucasian controls were analyzed to determine the R92Q carrier frequency., Results: Six of 25 adult MS patients (24%) with symptoms suggestive of TRAPS were found to carry the identical arginine-to-glutamine substitution at amino acid position 92 (R92Q or p.Arg121Gln) encoded by exon 4 of the TNFRSF1A gene. All R92Q heterozygotes had similar symptoms, including arthralgias/arthritis, myalgias, urticarial rash, and severe fatigue, which began before the onset of MS. In 5 of the 6 patients, we could identify family members who had TRAPS symptoms and had inherited the identical mutation. The R92Q exchange was also detected in 17 of 365 unselected MS patients (4.66%) and in 12 of 407 controls (2.95%) (P = 0.112). Three patients were heterozygous carriers of MEFV variants, in 1 patient in combination with the R92Q mutation., Conclusion: Autoinflammatory syndromes and especially late-onset TRAPS should be considered in MS patients who report symptoms such as arthralgias/arthritis, myalgias, urticarial rash, and severe fatigue.

Glomerulopathic light chains engage in pathological interactions with mesangial cells resulting in alterations in glomerular homeostasis. The crucial pathological events are centered in the mesangium and, therefore, research dealing with pathogenesis of these disorders is focused on this glomerular compartment. Particular physicochemical characteristics of these light chains are responsible for their ability to alter mesangial milieu leading to glomerular damage. An in vitro model has been used to dissect the processes involved. This model has been instrumental in providing a solid platform from which to observe in a dynamic fashion how mesangial cells handle pathogenic light chains and the sequential steps that are involved in the progressive glomerular damage. Key steps amenable to possible modulation have been defined and should provide a solid platform to design and test therapeutic interventions. In the past significant difficulties have been encountered in the development of animal models of light chain-induced glomerular damage. However, in the last few years a new generation of animal models has emerged to address whether what has been documented in vitro retains significance in vivo. Preliminary observations appear to substantiate this.

We report on bone marrow plasmacytosis in four cases of idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia (IPL). Pathologically, the plasma cells increased in number and accounted for 20-40% of nucleated cells of bone marrow. These plasma cells diffusely infiltrated or formed numerous clusters with 50-200 cells on histological sections. Some binuclear plasma cells and Russell bodies were seen, but all plasma cells showed mature cytomorphology. One case contained two lymphoid follicles with normal germinal centers. Immunoperoxidase studies of light chain determinants for plasma cells and their precursors demonstrated a polyclonal pattern. The immunohistochemical study revealed that there were no human herpes virus-8-positive cells. Bone marrow plasmacytosis of striking proportions may occur in a number of inflammatory conditions, chronic infections, autoimmune diseases, and hypersensitivity states. These reactive plasmacytoses, although sometimes striking, are generally composed of scattered, non-aggregated plasma cells. The four cases described here contained numerous tumor-like aggregations on mature plasma cells. Our four cases should be differentiated from plasma cell myeloma composed of mature plasma cells. However, electrophoresis generally demonstrated a broad-based polyclonal hypergammmaglobulinemia. Moreover, the immunohistochemical study revealed a polytypic nature of the plasma cells. To avoid overdiagnosis and overtreatment, it is important to be aware of the bone marrow findings of IPL.

A 77-yr-old man presented with marked peripheral blood and bone marrow plasmacytosis, marked hypergammaglobulinemia, and multiple autoantibodies. Serum protein immunofixation and immunophenotyping of bone marrow plasma cells by flow cytometry and immunohistochemistry disclosed polyclonal proliferation of plasma cells at various stages of differentiation. The presence of multiple autoantibodies in the patient's serum suggests that an autoimmune disease underlies the polyclonal proliferation of plasma cells.

Mevalonic aciduria (MVA) and hyperimmunoglobulinemia D syndrome (HIDS) represent the two ends of a clinical spectrum of disease caused by deficiency of mevalonate kinase (MVK), the first committed enzyme of cholesterol biosynthesis. At least 30 patients with MVA and 180 patients with HIDS have been reported worldwide. MVA is characterized by psychomotor retardation, failure to thrive, progressive cerebellar ataxia, dysmorphic features, progressive visual impairment and recurrent febrile crises. The febrile episodes are commonly accompanied by hepatosplenomegaly, lymphadenopathy, abdominal symptoms, arthralgia and skin rashes. Life expectancy is often compromised. In HIDS, only febrile attacks are present, but a subgroup of patients may also develop neurological abnormalities of varying degree such as mental retardation, ataxia, ocular symptoms and epilepsy. A reduced activity of MVK and pathogenic mutations in the MVK gene have been demonstrated as the common genetic basis in both disorders. In MVA, the diagnosis is established by detection of highly elevated levels of mevalonic acid excreted in urine. Increased levels of immunoglobulin D (IgD) and, in most patients of immunoglobulin A (IgA), in combination with enhanced excretion of mevalonic acid provide strong evidence for HIDS. The diagnosis is confirmed by low activity of mevalonate kinase or by demonstration of disease-causing mutations. Genetic counseling should be offered to families at risk. There is no established successful treatment for MVA. Simvastatin, an inhibitor of HMG-CoA reductase, and anakinra have been shown to have beneficial effect in HIDS.

Light chain deposition disease (LCDD) is a rare disorder that very uncommonly affects the lung. We report three cases of severe cystic pulmonary LCDD leading to lung transplantation. Such a presentation has never been previously reported. The three patients present with a progressive obstructive pulmonary pattern associated with numerous cysts diffusely distributed in both lungs. The disease was histologically characterized by non-amyloid amorphous deposits in the alveolar walls, the small airways and the vessels. It was associated with emphysematous-like changes and small airway dilation. Monotypic kappa light chain fixation was demonstrated on the abnormal deposits and along the basement membranes. Electron microscopy revealed coarsely granular electron-dense deposits in the same localizations. Mild extrapulmonary deposits were found in salivary glands in one patient. No immunoproliferative disorder was identified. We conclude that LCDD may primarily affect the lung, present as a pulmonary cystic disorder, and lead to severe respiratory insufficiency.

The monomeric form of IgM, also known as low molecular weight IgM, is found in increased concentrations in patients chronically infected with a variety of viral and bacterial pathogens or suffering from various autoimmune diseases. Whether monomeric IgM contributes to the disease process, however, is not known. To address this question, transgenic mice were created that secreted elevated levels of IgM monomers. In normal mice (C57BL/6), the presence of IgM monomers did not alter the composition of the immune system significantly: lymphocyte subsets and serum antibody levels were normal, with the exception of increased levels of IgM due to the presence of the monomers. Immune responses also appeared to be normal. Transgenic mice did develop antinuclear antibodies (ANA) earlier than non-transgenic littermates, but did not develop further indications of autoimmune disease. When the transgene was expressed in the autoimmune-prone strain of mice, B6.MRL-Tnfrsf6(lpr) (B6/lpr), these mice developed autoimmune manifestations more rapidly than non-transgenic littermates, including hypergammaglobulinemia, splenomegaly, and ANA production. Transgenic mice also displayed earlier evidence of immune complex deposition in the kidneys. From these results, we conclude that monomeric IgM does not induce autoimmune disease, but its presence can accelerate the onset of autoimmune manifestations in otherwise autoimmune prone animals.

Objective: To describe biochemical findings and the spectrum of mevalonate kinase (MVK) gene mutations as well as an associated TNFRSF1A low-penetrance variant in a series of patients with clinical features of the hyperimmunoglobulinemia D with periodic fever syndrome (HIDS)., Methods: The MVK gene was sequenced in 8 children and 1 adult (including 2 siblings) fulfilling the clinical criteria for HIDS. In addition, sequencing of exons 2, 3, 4, and 6 of the TNFRSF1A gene was performed in patients with only one or no MVK mutation. Mevalonate kinase (MK) enzyme activity in leukocytes and renal excretion of mevalonic acid were also measured., Results: Mutations in the coding region of the MVK gene were detected in 6 patients, and the most common mutation was V377I. Among these patients were 2 novel mutations, both of which were located in exon 6. These novel mutations resulted in the substitution of tryptophan (TGG) by a stop codon (TGA) at amino acid position 188 (W188X) and in the exchange of valine (GTG) for alanine (GCG) at amino acid position 203 (V203A). In 1 patient, a combination of one MVK (V377I) mutation and one TNFRSF1A (R92Q) mutation was present. The patient's clinical phenotype resembled a mixture of variant-type HIDS and tumor necrosis factor receptor-associated periodic syndrome (TRAPS). Her IgD values varied between normal and slightly increased, and the MK activity was in the low-normal range, while urinary mevalonate concentrations were always normal., Conclusion: The genotype findings indicate that a relatively small number of genes may be involved in the clinical manifestation of HIDS, with low-penetrance TNFRSF1A variants possibly influencing the HIDS phenotype or MVK mutations contributing to TRAPS.

Cadmium is a pervasive environmental contaminant. The primary route of exposure to the general population occurs via contaminated drinking water or food supplies. Our hypothesis was that cadmium could be a trigger for inducing autoimmune disease (AD) in genetically predisposed populations. Therefore, New Zealand Black/White F1 (NZBW) mice were exposed to cadmium via drinking water. Mice were exposed to: 0, 3, 30, 3000 or 10000 parts per billion (ppb) of cadmium in tap water for 2, 4, 28, or 31 weeks. After 4 weeks of exposure, in the group of mice exposed to 10000 ppb cadmium, there was an increased incidence of antinuclear antibodies (ANA). There was also deposition of immune complexes in all groups after 4 weeks of exposure. After 31 weeks, there were increases in IgG2a in mice exposed to low doses of cadmium. In an attempt to establish the progression from an autoimmune reaction to the development of AD, the biological marker for AD, proteinuria, was assessed. Onset of proteinuria was exacerbated by 11 weeks in mice exposed to cadmium. This data suggests that short-term exposure may result in a type of autoimmune reaction since the mice are beginning to produce ANA after only 4 weeks of exposure and there is immune-complex deposition in the kidney. Long-term exposure to cadmium appears to result in the exacerbation of AD as indicated by the development of proteinuria and continued presence of immune complexes in the kidney. The mechanism may involve the increased production of IgG2a, which is capable of forming immune complexes and causing autoimmune glomerulonephritis.

Objective: To investigate whether the increased interleukin-1beta (IL-1beta) secretion in hyperimmunoglobulinemia D and periodic fever syndrome is due to the accumulation of mevalonate kinase (MK), the substrate of the deficient enzyme, or the lack of its products, the isoprenoid compounds., Methods: The effects of lovastatin and farnesol (FOH), geranylgeraniol (GGOH), and mevalonate on peripheral blood mononuclear cells (PBMCs) from 8 patients with MK deficiency and from 13 controls were studied. Lovastatin inhibits isoprenoid biosynthesis by reducing the production of mevalonate. FOH and GGOH restore isoprenoid biosynthesis downstream from MK. Culture supernatants were collected for cytokine analysis 48 hours after stimulation with monoclonal antibodies against CD2 + CD28., Results: Lovastatin induced a 15-fold rise in IL-1beta secretion by normal anti-CD2 + CD28-stimulated cells (P < 0.001). This effect could be countered by mevalonate and, to a lesser extent, by FOH and GGOH. In the absence of lovastatin, mevalonate did not change IL-1beta secretion. Stimulated MK-deficient cells secreted 9-fold more IL-1beta than control PBMCs (P < 0.005), rising 2.4-fold in the presence of lovastatin. The effect of lovastatin on IL-1beta secretion was reduced by mevalonate, FOH, and GGOH. Isoprenoid biosynthesis in PBMCs from patients was impaired due to the endogenous MK deficiency. Bypassing this defect with FOH, in the absence of lovastatin, led to a 62% reduction (P < 0.02) in IL-1beta secretion by these cells., Conclusion: In this model, shortage of isoprenoid end products contributes to increased IL-1beta secretion by MK-deficient PBMCs, whereas excess mevalonate does not.

Medium osmolality increases with pCO2 at constant pH. Elevated pCO2 and osmolality inhibit hybridoma growth to similar extents in both serum-containing and serum-free media. The combination of osmolality and elevated pCO2 synergizes to negatively impact cell growth. IgG2a glycosylation by hybridoma cells was evaluated under elevated pCO2 (to 250 mmHg pCO2) and/or osmolality (to 476 mOsm/kg). IgG2a site occupancy did not change significantly under any of the conditions studied, which is consistent with the robust glycosylation of other antibodies produced under various environmental stresses. However, changes were observed in the IgG2a charge distribution. Changes in the isoelectric point (pI) were greater under hyperosmotic stress, increasing by 0.32 and 0.41 pH units at 435 mOsm/kg in serum-containing and serum-free medium, respectively. Hyperosmotic stress also resulted in a concomitant increase in the heterogeneity of the charge distribution. The mean pI in serum-containing medium decreased by 0.16 pH units at 250 mmHg pCO2 when osmolality was controlled at 320 mOsm/kg but increased by 0.20 pH units when the osmolality increased with pCO2 (195 mmHg pCO2-435 mOsm/kg). In serum-free medium, elevated pCO2 did not alter pI, regardless of medium osmolality. In contrast to elevated osmolality at control pCO2, elevated pCO2 did not significantly alter the IgG2a charge heterogeneity under any of the conditions studied. The IgG2a was not sialylated, so sialylation changes were not responsible for changes in the charge distribution. IgG2a galactose content decreased with elevated osmolality, as a result of either elevated NaHCO3 or NaCl. However, when osmolality was controlled at elevated pCO2, the galactose content tended to increase. The mannose content decreased with increasing stress, while the fucose content remained relatively unchanged. It is likely that the observed increases in the pI of murine IgG2a were due to increased organellar pH, which is reflected by increased specific beta-galactosidase activity in the supernatant.

We describe the peculiar histopathology of the bone marrow in a case of IgG/lambda MGUS. Striking eosinophilic crystals with a rectangular, rhomboid or square shape lay in the interstitium, sometimes in optically empty spaces, but failed to elicit a foreign body giant cell reaction. Their histochemical properties, immunoreactivity for anti-lambda light chain antiserum, and ultrastructural features strongly supported their relationship with the paraprotein synthesized by the monoclonal plasma cells. The crystals were not observed on bone marrow aspirate smear, suggesting that they had formed during trephine biopsy processing or, alternatively, that they had been removed during the smear preparation. We feel that pathologists should be aware of the existence of this type of crystals, which differ from both the amyloid deposits and the proteinaceous material sometimes observed in plasma cell proliferations. Their presence in the bone marrow should alert the clinician to investigate the involvement of other organs with immunoglobulin deposits.

Background: The pathophysiology of eosinophilia and hyper-IgE is not fully elucidated yet., Objective: To clarify the pathophysiology of a patient with remarkable eosinophilia and hyper IgE, we examined cytokine levels in serum, surface antigens of peripheral blood eosinophils and IgE production in vitro., Results: Concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-3 (IL-3), interleukin-4 (IL-4), interleukin-5 (IL-5), and granulocyte/macrophage-colony stimulating factor (GM-CSF) in the serum were 21 pg/mL, <15 pg/mL, <15 pg/mL, 8 pg/mL, and <5 pg/mL pg/mL, respectively. Newly expressed surface antigens CD4, CD25, CD69, and HLA-DR, but not CD54, were observed on peripheral blood eosinophils. Extremely high levels of IgE secretion was found in the patient's mononuclear cells without stimuli; this was not enhanced by IL-4 or IL-4 plus anti-CD40 monoclonal antibody stimulation. Furthermore, highly purified B cells spontaneously produced large amounts of IgE and the production was not enhanced in addition of his T cells., Conclusion: The eosinophils were activated, and the B cells spontaneously produced IgE independently of T cells or cytokines, suggesting that intrinsic abnormality of B cells leading to dysregulated production of IgE in this disease.

Tissue deposition of monoclonal immunoglobulin light chains is a serious complication in some patients with B cell proliferative disorders. The deposits are typically fibrillar and Congophilic in amyloid (AL) and non-fibrillar and Congophobic in light chain deposition disease (LCDD), and rarely coexist in the same patient. From post-mortem tissue of an individual with fibrillar and non-fibrillar kappa light chain deposits in different sites, we separately extracted and analysed biochemically and immunochemically the non-amyloid deposits from isolated glomeruli, the amyloid from isolated renal arteries and the amyloid from myocardium in which the only deposits were amyloid restricted to mural arteries. Western blotting analysis of both the extracted amyloid and the non-amyloid deposits demonstrated 25-kD bands immunoreactive with anti-kappa antibody, and the identity of the N-terminal amino acid sequences that belong to the variable region kappaIV light chain subgroup. This is the first human disease in which antigenically similar but morphologically different deposits have been separately biochemically analysed. We propose that combined LCDD and AL is an ideal human disease to study the relationships and the factors that influence the conversion of non-amyloidogenic to amyloidogenic conformations.

Light chain deposition disease is a severe complication of certain immunoproliferative disorders, due to the secretion of a monoclonal light chain which precipitates close to basement membranes of several tissues. A kappa isotype restriction and an unusual frequency of a variable region subgroup (VkappaIV) suggest that precise structural features govern the propensity of pathogenic light chains to precipitate in extracellular spaces. We studied primary structures of light chains from six patients with light chain deposition disease in comparison with light chains from other pathological conditions. Sequence alignment revealed the presence of certain amino acids only in light chain deposition disease, in particular non-polar replacing hydrophilic residues. To determine the role of these residues, structures of the variable domain from four kappa chains belonging to VkappaI and VkappaIV subgroups responsible for deposition disease were modeled using known immunoglobulins as templates. The most evident structural features shared by all pathogenic light chains were hydrophobic residues exposed to the solvent in complementarity determining regions 1 or 3. In contrast to immunoglobulin light chain-related amyloidosis, where deposition of organized material might be due to electrostatic interactions between light chain dimers, hydrophobic interactions could enhance amorphous precipitation in non-amyloid light chain deposition disease.

In an X-linked immunodeficiency with hyper IgM (X-HIM), several mutations of genes coding for CD40 ligand are responsible for B-cell defects. However, it is controversial whether the defective class switching from IgM to IgG or IgA but not IgE is rescued by in vitro stimulations or not. In six X-HIM patients, signaling through CD40 induced IgE but not IgG or IgA secretion in vitro. When transferred into SCID mice, however, B-cells of X-HIM patients secreted as much IgG and IgA as those of healthy controls. Moreover, sIgG and sIgA expressions were also induced by the in vivo stimulation. These results support that B-cells of X-HIM patients are defective of in vitro class switching from IgM to IgG or IgA and show that the in vivo stimulations rescue the defective class switching and suggest that the class switching of IgE and that of IgG or IgA might be regulated quite differently.

The imbalance of the redox state in cells and body fluids in HIV-1-infected patients may result in progression of the disease as well as in immunologic disfuctions. In this report, we have evaluated whether the direct administration of high doses of reduced glutathione (GSH) exerts any antiviral activity and/or improves immune functions in a murine immunodeficiency animal model. Intramuscular administration of 50 or 100 mg GSH/mouse for five consecutive days weekly to LP-BM5-infected mice did not show local or systemic signs of acute toxicity. During the first 3 weeks from infection, a period in which clinical signs of disease were not yet detectable, GSH significantly reduced the viral load in lymph nodes and spleen as evaluated by a PCR semiquantitative assay of the proviral DNA content. At 10 weeks a GSH concentration-dependent reduction of splenomegaly, lymphadenopathy and hypergammaglobulinemia was evident in all treated mice. Evaluation of proviral DNA content showed that GSH was effective in inhibiting LP-BM5 infectivity in lymph nodes, spleen, and bone marrow at 100 mg/day, while it was less effective when administered at 50 mg/day. At 10 weeks some animals receiving the highest GSH dose died, thus only the mice receiving 50 mg GSH were followed up to 15 weeks without signs of toxicity. In this case, almost not significant differences among infected untreated or treated animals were observed. Thus, GSH is effective in reducing the proviral DNA load in the first period of infection. These data and the failure of sulfhydril supplementation to further counteract the progression of disease after 10 weeks of infection suggest that combinations of GSH and other antiviral agents may be useful for improving current antiviral therapies.

Crossed affinoimmunoelectrophoresis using concanavalin A and Aleuria aurantia lectin as diantennary glycan- and fucose-specific affinocomponents, respectively, was applied to study changes in the concentration and glycosylation of the acute phase protein alpha 1-acid glycoprotein (AGP) in sera obtained from patients with hyperimmunoglobulinemia D and periodic fever syndrome. Increases in concentration of AGP compared to control values were found not only during attacks, but also during remissions. Compared to healthy controls, the presence of diantennary glycan-containing glycoforms of AGP also increased during febrile attacks, while no changes were found during remissions. A continuous high degree of alpha 1-->3 fucosylation was accompanied by a continuous high expression of sialyl Lewisx on AGP. Despite the clinical picture of recurrent febrile attacks with asymptomatic intervals, these studies indicate that hyperimmunoglobulinemia D should be considered a condition of persistent inflammation.

The objective of this study was to investigate the spectrum of morphologic features in myocardial biopsy specimens from patients with cardiac immunocyte-derived (AL) amyloidosis. Cardiac involvement is the most important predictor of survival in AL amyloidosis. Myocardial biopsy remains the method of choice for diagnosing cardiac amyloidosis when noninvasive studies give equivocal results. Histologic, immunohistochemical, ultrastructural, and morphometric studies were made on myocardial biopsy specimens from 11 patients in whom the diagnosis of AL amyloidosis was based on the demonstration of a monoclonal immunoglobulinopathy and of amyloid deposits in tissues. Histopathologic study showed amyloid in 10 of the 11 biopsies. In one biopsy (Congo red negative), the diagnosis was made by ultrastructural identification of amyloid fibrils. In all patients, the deposits formed perimyocytic layers that measured up to 18 microns in thickness. These layers formed along the basement membranes, which were partially preserved in 5 patients and unrecognizable in 6. Interstitial nodular deposits were also present in 5 patients. Immunohistochemical studies for the characterization of the proteins in the amyloid deposits were diagnostic in 1 patient and confirmatory in 10. Nodular deposits, thick perimyocytic layers of amyloid and small myocyte diameters were associated with shorter survival of the patients. Small-vessel involvement and myofilament loss occurred in all patients. In conclusion, myocardial biopsy serves to (1) establish the diagnosis of cardiac amyloidosis; (2) characterize immunohistochemically the proteins in the amyloid fibrils and (3) assess the degree of myocyte damage and atrophy.

The glomerulopathy of monoclonal immunoglobulin light chain deposition disease is a progressive disorder characterized by accumulation of monoclonal light chains and matrix proteins in the mesangium. To define the role of light chains in this process, cultured rat mesangial cells were exposed to different light chains and human albumin. Two light chains were purified from the urine of patients who had biopsy-proven light chain deposition disease. These proteins inhibited mesangial cell proliferation and increased production of matrix proteins, including type IV collagen, laminin, and fibronectin. By immunocytochemistry and bioassay, transforming growth factor-beta (TGF-beta) production and activity increased when mesangial cells were exposed to these proteins. Furthermore, anti-TGF-beta antibody abolished the inhibition of cell proliferation and the increase of extracellular matrix protein production caused by these light chains. These findings were not observed in mesangial cells exposed to human albumin and two other light chains previously characterized to be tubulopathic. We concluded that the glomerulopathic light chains increased TGF-beta, which inhibited mesangial cell proliferation and increased matrix protein production. Together with overexpression of TGF-beta in affected glomeruli of light chain deposition disease, light chain-mediated stimulation of mesangial cells to produce TGF-beta appears to be a key pathological mechanism of this disease.

The hyperimmunoglobulinemia D and periodic fever (hyper-IgD) syndrome is typified by recurrent febrile attacks with abdominal distress, joint involvement (arthralgias/arthritis), headache, skin lesions, and an elevated serum IgD level (> 100 U/mL). This familial disorder has been diagnosed in 59 patients, mainly from Europe. The pathogenesis of this febrile disorder is unknown, but attacks are joined by an acute-phase response. Because this response is considered to be mediated by cytokines, we measured the acute-phase proteins C-reactive protein (CRP) and soluble type-II phospholipase A2 (PLA2) together with circulating concentrations and ex vivo production of the proinflammatory cytokines interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-6, and tumor necrosis factor alpha (TNF alpha) and the inhibitory compounds IL-1 receptor antagonist (IL-1ra), IL-10, and the soluble TNF receptors p55 (sTNFr p55) and p75 (sTNFr p75) in 22 patients with the hyper-IgD syndrome during attacks and remission. Serum CRP and PLA2 concentrations were elevated during attacks (mean, 213 mg/L and 1,452 ng/mL, respectively) and decreased between attacks. Plasma concentrations of IL-1 alpha, IL-1 beta, or IL-10 were not increased during attacks. TNF alpha concentrations were slightly, but significantly, higher with attacks (104 v 117 pg/mL). Circulating IL-6 values increased with attacks (19.7 v 147.9 pg/mL) and correlated with CRP and PLA2 values during the febrile attacks. The values of the antiinflammatory compounds IL-1ra, sTNFr p55, and sTNFr p75 were significantly higher with attacks than between attacks, and there was a significant positive correlation between each. The ex-vivo production of TNF alpha, IL-1 beta, and IL-1ra was significantly higher with attacks, suggesting that the monocytes/macrophages were already primed in vivo to produce increased amounts of these cytokines. These findings point to an activation of the cytokine network, and this suggests that these inflammatory mediators may contribute to the symptoms of the hyper-IgD syndrome.

Light-chain deposition disease (LCDD), a rare form of monoclonal gammopathy, is characterized by deposits of amorphous light-chain material, mainly in the kidneys but also in various other organs. Here we present the first report of a light-, electron microscopic and immunohistochemical study of the globes of a patient suffering from LCDD secondary to multiple myeloma. Massive deposits of kappa light chains similar to those typically present in the kidneys were found beneath the basement membrane of the ciliary pigment epithelium, on vessels of the ciliary body, within the collagenous zones of Bruch's membrane, and in the innermost part of the choroid. The choriocapillaris in the macular area was partly obstructed by these deposits, and an exudative retinal detachment was present. Whether this detachment was the consequence of disturbed circulation of the choriocapillaris remains speculative.

Epstein-Barr virus (EBV) and recombinant interleukin-4 (rIL-4) induce IgE production by normal B-cells. We demonstrate here the difference in IgE synthesis in patients with elevated IgE levels and normal control subjects. EBV and rIL-4 induced the synthesis of IgE by surface IgE-negative B-cell precursors isolated by cell sorting. IgE synthesis in normal subjects became apparent in the second week with increasing rIL-4 concentrations, whereas in patients with elevated IgE levels, there was a marked elevation in IgE synthesis without rIL-4 stimulation. We did not observe the presence of DNA rearrangement occurring between IgM and IgE switch regions (S mu and S epsilon, respectively) during switching to IgE isotype in patients with elevated IgE levels. We found that with the limited sensitivity of Southern blotting, this method may not be useful for the study of B-cell populations in which only a small percentage of cells have undergone switching.

Increased levels of serum IgE and eosinophilia have been described in human immunodeficiency virus (HIV) infection, almost exclusively in patients with CD4+ cell count < 200 cells/microliters. IgE production is regulated by CD4+ T helper type 2 (Th-2) lymphocytes, producing interleukin 4 (IL-4) and expressing a ligand for the B cell-specific CD40 molecule (CD40 ligand [L]). A shift to a Th-2-like pattern of cytokine secretion has been postulated to be associated with progression toward acquired immunodeficiency syndrome (AIDS). We studied three AIDS patients with very high levels of IgE and almost complete depletion of CD4+ lymphocytes, suggesting that IgE synthesis could not be driven by CD4+ cells. IgE in vitro synthesis by cells from such patients was, however, inhibited by anti-IL-4. We show that both CD8+ T cell lines and the majority of CD8+ T cells clones derived from these patients produce IL-4, IL-5, and IL-6 in half of the cases together with interferon gamma (IFN-gamma). 44% of CD8+ T cell clones expressed a CD40L, and the supernatants of the clones were capable of inducing IgE synthesis by normal B cells costimulated with anti-CD40. CD8+ T cells in these patients therefore functionally mimic Th-2 type cells and may account for hyper-IgE and eosinophilia in the absence of CD4+ cells. The presence of such CD8+ cells may also provide a source of IL-4 directing the development of predominant Th-2 responses in HIV infection.

IgE is highly glycosylated, but the function of the oligosaccharide side chains is largely unknown. The previous discovery of an animal lectin, IgE-binding protein (epsilon BP), affords an opportunity to study potential carbohydrate-dependent effector functions of IgE. epsilon BP is a beta-galactoside-specific lectin with binding affinity for IgE and is now known to be equivalent to carbohydrate-binding protein 35 and the Mac-2 Ag; thus, it may have multiple functions in addition to IgE binding. We have previously shown that rat r epsilon BP recognizes sialidase-treated human myeloma IgE to a much greater extent than the untreated IgE. In contrast, human epsilon BP binds essentially equivalently to a monoclonal murine IgE with or without sialidase pretreatment. To validate a possible role for epsilon BP in the IgE system, we investigated the pattern of recognition of epsilon BP for various polyclonal human IgE samples. We show that polyclonal IgE derived from four individuals with hyper-IgE syndrome or atopic dermatitis recognizes epsilon BP and that there is individual variation in the proportion of IgE recognized by epsilon BP, ranging from greater than 60% for one sample to almost undetectable levels in another. We conclude that epsilon BP does indeed recognize polyclonal IgE and that this recognition is modulated by sialylation of IgE oligosaccharides. Furthermore, there exist different IgE glycoforms, varying in the degree of sialylation, and these are distributed in a distinct manner in different individuals.

A 77 year-old female admitted with costal and right clavicular tumors and multiple osteolytic lesions. In January 1983, a diagnosis of mature type plasmacytoma was made based on the histopathological examination of the right clavicular tumor. The amounts of serum protein and IgA (kappa) M-protein were 7.5 g/dl and 2.1 g/dl, respectively. A myelogram revealed 21% of mature plasma cells with 31.3 x 10(4) nucleated cells/microliter. Four months later following a chemotherapy started in March 1983, the tumor size became smaller with undetected M-protein by an immunofixation method. Besides, a serum protein analysis showed 24.6% of gamma-globulin and 1,980 mg/dl of IgG. However, in December 1983, the right clavicular and costal tumors regrew. The second biopsy specimen showed diffuse proliferated plasmablastoid cells which reacted only to anti-kappa antibody. By August 1984, the patient had systemic subcutaneous tumors as well as polyclonal IgG up to 3,356 mg/dl suggesting rapid progression of the disease. A myelogram showed 7.4% of mature plasma cells. In December 1984, the patient died of complicated obstructive ileus due to multiple mesenteric tumor. In this study we discussed on the role of M-protein loss and increased of normal globulin level in a tumor-forming type multiple myeloma.