Interleukin-18 overexpression as a hallmark of the activity of autoimmune inflammatory myopathies

The objective of this study was to explore the role of interleukin (IL)-18 in patients with inflammatory myopathies (IM) such as dermatomyositis (DM) and polymyositis (PM) in relation to the possible predominance of a Th1 immune response in their pathogenesis. Serum concentrations of IL-18, interferon (IFN)-gamma, IL-4 and IL-6 were measured in six patients by enzyme-linked immunosorbent assay (ELISA). IL-18 expression was evaluated by in situ hybridization (ISH), whereas CD68, CD8 and CD83 were investigated by immunohistochemistry (IHC) to define the main producers of IL-18. Lastly, the expression of both IL-18 receptor (IL-18R) and monocyte chemoattractant protein (MCP)-1 was also explored by IHC. High serum levels of IL-18 and IFN-gamma, and conversely low titres of IL-4 and IL-6, were demonstrated in both diseases. In addition, IL-18 was overexpressed in muscle biopsy specimens from patients with IM. Both macrophages and dendritic cells (DC) surrounding either perivascular and perimysium areas in DM or endomysium in PM were the main producers of IL-18. Endothelial cells (EC), smooth muscle cells (SMC) and CD8(+) T cells expressed a high content of IL-18R. Vessel cells overexpressed MCP-1 in parallel with IL-18R. High concentrations of serum IL-18 as well as muscular up-regulation of IL-18 and IL-18R suggest that deregulation of the IL-18/IL-18R pathway is a pathogenetic mechanism in IM. Measurement of IL-18 may thus predict the severity of both DM and PM.

Sjögren's syndrome: an autoimmune disorder with otolaryngological involvement

Sjorgen's syndrome (SS) is an autoimmune exocrinopathy characterized by lymphocyte infiltration of salivary and lacrimal glands that leads to progressive xerostomia and xerophtalmia. One-third of patients suffer of systemic manifestations including arthritis, fever, fatigue and mucosal dryness whereas those with major salivary involvement show an increased risk to develop low-grade non-Hpdgkin lymphomas. In addition, a minority of patients show symptoms related to progressive hearing loss whose pathogenesis remains undefined. Both deposition of autoantibodies to antigens of the inner-ear structures and infiltration by autoreactive T-cells have been implicated in its pathogenesis. In this context, high levels of autoantibodies to both cardiolipin and M3 muscarinic receprtors as well as to ciliar epitopes of the cochlear cells have been recently described. Here we review recent advances on the pathodgenesis of SS with a particular focus to otolaryngological manifestations.

Primary intimal sarcoma of the thoracic aorta

Primary aortic tumors are well known for both their rarity and variability in clinical presentation and usually are diagnosized post-operatively or by post-mortem examination. Intimal sarcoma is a recurrent histological variant and the involvement of the thoracic aorta is an unusual presentation. Angiography and computed tomography are accurate methods to evaluate aortic tumors though transesophageal echocardiography is actually used for the differential diagnosis. Here, we describe an unusual intimal sarcoma of the thoracic aorta whose clinical feature strongly mimicked a diffuse thrombotic disease.

Up-regulation of IL-18 and predominance of a Th1 immune response is a hallmark of lupus nephritis

There is evidence that nephritis is dominated by a Th1 immune response in systemic lupus erythematosus. Since IL-18 promotes polarization of the immune response toward Th1, we investigated the role of this cytokine in lupus nephritis (LN). A total of 133 lupus patients and 44 healthy subjects were enrolled. Demographic and clinical characteristics with renal biopsy data were recorded. IL-18 along with IFN-gamma and IL-4, two prototypical of Th1 and Th2 cytokines, were measured in serum by ELISA. Peripheral blood lymphocytes were analysed by flow cytometry for IFN-gamma and IL-4. IL-18 expression was determined by immunohistochemistry in 13 renal biopsy specimens from patients with LN and 2 controls. Serum IL-18 was higher in lupus patients than in controls. Levels of IL-18 correlated with urinary microalbumin and were increased in patients with LN when compared to those without LN. IL-18 expression was also increased within the glomeruli of nephritic patients and was primarily detected within the mesangial matrix and in infiltrating mononuclear cells. Measurement of IFN-gamma and IL-4 in either sera or peripheral blood lymphocytes showed high IFN-gamma along with low IL-4 expression in LN patients compared to patients without nephritis. A positive correlation between serum IL-18 and IFN-gamma levels was found. IL-18 may play a prominent role in the pathogenesis of LN by promoting a cytokine imbalance towards a Th1 immune response. Measurement of IL-18 may be helpful for the early identification of lupus patients with LN and may help gauge the response to treatment in patients with active LN undergoing treatment.

Enhancement of T cell apoptosis correlates with increased serum levels of soluble Fas (CD95/Apo-1) in active lupus

Peripheral T cell apoptosis is upregulated in active SLE, in parallel with high expression of both membrane-bound and soluble (s) Fas. Previous studies postulated that sFas down-regulates apoptosis in vitro through its blockade of the Fas-L of cytotoxic cells. We have investigated the extent of apoptosis and sFas levels in 14 patients with active (group A) and 11 with inactive SLE (group B). Fas was predominantly expressed by CD3+ cells from group A, whose increased serological levels of sFas were linearly correlated with the TUNEL positive cell population, whereas low titers paralleled a mild level of apoptosis in group B. This association was also investigated by measuring the effect of sFas on both cell proliferation and caspase activation. We found that incubation with sFas greatly suppressed proliferation of CD3+ cells, especially in group B, and in control cells from healthy donors whose content of CPP32 active products was significantly increased. We postulate that sFas promotes a pro-apoptogen effect, which would explain the high susceptibility to apoptosis in active lupus, and that the apoptosis program itself includes release of sFas to spread the death signal.

Serum elevations of soluble Fas (CD95/apo-I) concur in deregulating T cell apoptosis during active lupus disease

Apoptosis is deregulated in active systemic lupus erythematosus and Fas is overexpressed by T cells, although the role of its soluble form (sFas) is unclear. We have explored both the biological significance and structure of sFas in relation to the disease activity. Serum levels of both sFas and sFas-L were correlated with T cell apoptosis in 26 systemic lupus eythematosus patients along with measurement of poly (ADP) ribose polymerase and CK18. In addition, both proliferative rate and change of ploidy were measured in CD3+ cells after treatment with sFas. Both sFas and sFas-L correlated with apoptosis in patients with active systemic lupus eythematosus. Incubation with sFas greatly suppressed proliferation of CD3+ cells from inactive patients and healthy donors, whereas immunoprecipitation revealed both the 48-kDa full-length Fas and the 26-kDa splicing variant in sera from active patients. We postulate that sFas is released to exert a pro-apoptogen effect. It seems possible that the apoptosis program itself includes the shedding/secretion of different forms of Fas to spread a death signal.

Familial systemic sclerosis following exposure to organic solvents and the possible implication of genetic factors

Both genetic and environmental factors are suspected to play a role in the pathogenesis of systemic sclerosis. We compare its occurrence in 3 sisters working in a dry cleaner's shop and exposed to occupational inhalation of organic solvents. Two sisters showing the human leukocyte antigens (HLA)-DR11/DQ7 haplotype were affected. The third has maintained the same job as the others for over 10 years and has no signs of the disease. The fact that she has a different HLA haplotype points to the significance of genetic factors in increasing the risk of systemic sclerosis. It is suggested that the DR11/DQ7 haplotype enhances the development of a clinical subset of systemic sclerosis associated with production of anti-topoisomerase-I antibodies, and that environmental triggers prime the disease in subjects with this genetic background.

Anti-Fas (CD95/Apo-I) autoantibodies and soluble Fas levels concur in T cell depletion in HIV type 1 infection

Deregulation of the Fas/FasL pathway in activated T cells is suspected to contribute to the abnormal apoptosis that drives their progressive depletion during HIV-1 infection. However, the role of serum soluble Fas (sFas) is unclear. Here we investigated both sFas and anti-Fas IgG levels in a cohort of 227 HIV-1-infected patients with respect to their T cell apoptosis. By using optimized ELISAs, we found that serum titers of sFas and anti-Fas were linearly correlated in 17 severely lymphopenic subjects as compared with other patients grouped in relation to their single expression of anti-Fas and sFas, or with double-negative control patients. Cytofluorimetric measurement of the subdiploid DNA-containing cell population by both PI and TUNEL revealed an increased occurrence of cell death in vitro, in particular in patients with elevations of sFas. We also found that fresh CD4(+) cells from these patients showed high levels of both caspase 3 (CPP32) and its molecular targets, namely PARP and CK18. In addition, their in vitro proliferative rate was inhibited by sFas, in particular in patients with undetectable levels of the soluble receptor in vivo as well as in normal donors. In these subjects the Fas-related caspase 8 (FLICE) was significantly increased in cells treated with the recombinant Fas. These results support the contention that functionally exhausted T cells may undergo apoptosis in response to the persistent in vivo stimulation by sFas. This may elucidate the described occurrence of enhanced cell death in advanced HIV-1 infection in association with serum elevations of the soluble receptor.

LFA-1 expression on CD4(+)CD45RO(+) peripheral blood T-lymphocytes in RR MS: effects induced by rIFNbeta-1a

We investigate the in vivo and in vitro effects of short-term treatment with recombinant Interferon beta-1a (rIFNbeta-1a) on CD4(+)CD45RO(+) activated/memory peripheral blood T-lymphocytes (PBTLs) expressing Leukocyte Function Antigen-1 (LFA-1; CD11a/CD18) in relapsing-remitting (RR) Multiple Sclerosis (MS) patients. Blood samples were obtained from 10 RR MS patients before and after 2, 4 and 6 months of rIFNbeta-1a (Avonex) treatment. For each sample, the percentage of CD4(+)CD45RO(+)CD11a(+) (CD11a(dim) and CD11a(bright)) T-cells was evaluated in in vivo PBTLs and in untreated or rIFNbeta-1a (1000 U/ml) or recombinant soluble Intercellular Adhesion Molecule-1 (ICAM-1, the ligand for LFA-1) (400 ng/ml) treated cultured PBTLs by triple fluorescence flow-cytometry (FACS analysis). Soluble ICAM-1 (sICAM-1) serum levels were evaluated by ELISA. In vivo, the percentage of CD4(+)CD45RO(+), CD4(+)CD45RO(+)CD11a(+), CD4(+)CD45RO(+)CD11a(dim) PBTLs increased after 4 and 6 months of rIFNbeta-1a treatment compared to pretreatment and 2 months of treatment (p<0.05). The CD11a expression per se did not change during the time course. Soluble ICAM-1 (sICAM-1) serum levels also increased (p<0.05) after 4 and 6 months of treatment. When T-cells, obtained from the blood of the same patients before and during in vivo treatment, were cultured either untreated or treated with rIFNbeta-1a, they showed an increase in the percentage of CD4(+)CD45RO(+) T-cells expressing CD11a(bright) (p<0.05). The addition of recombinant sICAM-1 to untreated cultures decreased the percentage of CD4(+)CD45RO(+) T-cells expressing CD11a. This last finding seems to support an indirect effect in vivo of rIFNbeta-1a via sICAM-1 on this T-cell subset, since the ICAM-1 soluble form, induced in vivo in serum by rIFNbeta-1a but lacking in in vitro conditions, keeps the percentage of CD11a(+) unchanged within CD4(+)CD45RO(+) T-cells and induces their expression of CD11a(dim), probably preventing T-cells from transmigrating.

Cationic myeloma M-components frequently show cross-reacting anti-DNA, Anti-F(ab')2 and anti-nucleosome specificities

134 cationic human IgG myeloma proteins were studied for expression of anti-DNA Idiotypic markers. 64 were studied for 16/6, F4, 3I, and 8.12, and 70 for expression of F4 and 3I. 31.3% showed at least one anti-DNA Id marker and many cationic myelomas were also positive for anti-DNA ELISA reactivity as well as anti-F(ab')2. Five M-components showed anti-nucleosome reactivity and one without detectable anti-DNA Id markers showed very strong anti-nucleosome antibody which was also inhibited by DNA and Sm antigens. Anti-idiotypic antisera produced either against Id(+) anti-DNA reactive M components or F(ab')2 fragments of affinity purified SLE IgG anti-DNA showed preferential cross-reactive idiotype reactivity between Id(+) anti-DNA reactive M components. Our findings indicate that human IgG monoclonal proteins positive for several common anti-DNA Ids and possessing anti-DNA ELISA reactivity, can serve as models for SLE Id marker antigens and as a source to prepare anti-Ids from IVIG.

Autoantibodies as chameleons

Autoantibody determinations are frequently used by rheumatologists to establish the diagnosis or assess follow up clinical status in patients with connective tissue diseases. Such autoantibodies are often presumed to have harmful effects, particularly since some such as anti-native DNA or anti-Ro have frequently been related to tissue damage or to functional impairments. However, there are many other autoantibodies which react with antigenic components of normal autologous tissues which have not been demonstrated to have self-damaging or harmful effects. Some of these autoantibodies may actually represent natural built-in mechanisms of feed-back inhibition, serving to modulate normal physiologic function. Autoantibodies may be compared to chameleons since their function or quality is often judged by the company they keep or by their anatomical localization. Since many autoantibodies to intra-cellular products seem to react with active sites of important biologic molecules, they may provide us with a much sharper image of a number of natural cellular functions.

Fas-L up-regulation by highly malignant myeloma plasma cells: role in the pathogenesis of anemia and disease progression

Highly malignant myeloma cells up-regulate their Fas-ligand (Fas-L) to escape immune surveillance by Fas(+) cytotoxic cells. Here it is demonstrated that this abnormality is involved in the pathogenesis of the severe anemia associated with progression of multiple myeloma (MM). By measuring Fas and Fas-L in plasma cells and erythroblasts from 19 MM patients and 5 with monoclonal gammopathies of undetermined significance (MGUS), it was found that both Fas-L(+) myeloma cells and Fas(+) erythroid progenitors were significantly increased in patients with stage III MM whose erythroblasts, cultured in the presence of autologous plasma cells or their supernatant, underwent prompt apoptosis as evaluated by propidium iodide staining, the TUNEL assay, and detection of the APO2.7-reactive mitochondrial antigen. Flow cytometry of fresh erythroblasts revealed a considerable expression of the caspases CPP32 and FLICE in both their constitutive proenzymatic forms and in cleaved subunits. By contrast, their intracytoplasmic expression was defective in patients with inactive disease and MGUS controls. The evidence that Fas-L(+) myeloma clones directly prime erythroblast apoptosis in vivo was further supported by the occurrence of fluorescein isothiocyanate-TUNEL(+) erythroblasts juxtaposed to myeloma cells in bone marrow smears. These results strongly suggest that the deregulated apoptosis in myeloma clones plays an active role in the progressive destruction of the erythroid matrix by a cytotoxic mechanism based on up-regulation of Fas-L.

VEINCTR-N, an immunogenic epitope of Fas (CD95/Apo-I), and soluble Fas enhance T-cell apoptosis in vitro. II. Functional analysis and possible implications in HIV-1 disease

BACKGROUND

Recent studies indicate that soluble Fas (sFas) may modulate T-cell apoptosis, since it inhibits Fas-ligand (Fas-L)-mediated cytotoxicity in vitro. Here, we explored whether the soluble receptor and its major immunogenic domain, namely VEINCTR-N, interfered with apoptosis of T cells from human immunodeficiency virus-type 1 (HIV-1)+ subjects showing serum elevations of both the soluble receptor and anti-Fas antibodies, and with that of several T-cell lines.

MATERIALS AND METHODS

Both proliferation and apoptosis extent of T cells from 16 HIV-1+ patients showing serum anti-VEINCTR-N immunoglobulin G (IgG) and 15 controls were tested after incubation with sFas and three 8-mer peptides of its first consensus sequence that included VEINCTR-N. Several cell lines were also investigated by flow cytometry for their expression of Ki-67, the APO2.7-related mitochondrial protein, and the annexin-V. In addition, we evaluated the expression of Fas-L and caspases FLICE, CPP32 and ICE either by flow cytometry, immunoblotting, and/or reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Cell proliferation in cultures from both patients and controls was affected significantly by sFas and VEINCTR-N. However, a prevalent increase of the subdiploid DNA-containing cell population occurred within these cultures. Similarly, Jurkat, CEM cells, and a mouse WR19L transformant overexpressing native human Fas underwent prompt apoptosis, which was detected as enlargement of APO2.7-reactive and annexin-V-positive populations. By exploring the Fas pathway in Jurkat cells, we found that both apoptosis inducers acted through Fas, since Fas-L, as well as CPP32 and FLICE were activated. By contrast, ICE was up-regulated only in control cells treated with tumor necrosis factor alpha (TNFalpha).

CONCLUSIONS

These data suggest that the soluble molecular forms of Fas prime cell death in Fas-positive cells. Therefore, the shedding of high amounts of sFas in HIV- 1 disease is possibly entrusted with amplification of the death execution program by cells functionally exhausted and committed to die. It is conceivable that the appearance of anti-Fas antibodies reflects an attempt by the immune system to neutralize these effective forms of the receptor and its structurally degraded domains, such as VEINCTR-N.

Immunogenicity of an eight amino acid domain shared by Fas (CD95/Apo-I) and HIV-1 gp120. I. Structural and antigenic analysis

Previous studies have demonstrated that immunoglobulin G (IgG) antibodies to VEINCTR-N, a domain shared by Fas (CD95/Apo-I) and gp120, contribute to T-cell apoptosis during human immunodeficiency virus-type 1 (HIV-1) infection as a result of the agonist cross-linking of Fas. The present work was designed to determine whether these molecules are elicited primarily to HIV-1 or the cell receptor.

MATERIALS AND METHODS

Sera from 439 HIV-1-infected patients were screened by ELISA for their reactivity to VEINCTR-N. Subjects with significant serum elevations of IgG anti-VEINCTR-N were further investigated. Immunologic parameters, including CD4+ and CD8+ lymphocyte count, extent of T-cell apoptosis, occurrence of both anti-Fas antibodies and circulating soluble Fas titers, and reactivity to the 8-mer peptides resembling the flank-regions of VEINCTR-N on both gp120 V3 loop and Fas were examined. In addition, the antigenicity of these domains was assessed by biochemical and computerized analyses.

RESULTS

21 patients with significant levels of IgG to VEINCTR-N showed both an increased extent of peripheral T-cell apoptosis and binding to full-length Fas. A weak, though positive correlation of the anti-VEINCTR-N activity with its antecedent peptide on Fas was also found. Charge and structural analysis revealed that, although the extended 26-amino acid (a.a.) regions on both proteins were hydrophilic, the Fas peptide adjacent to VEINCTR-N expressed a short beta-conformed a.a. sequence in contiguity with a portion of the shared epitope, also in beta-sheet conformation. Patterns of antigenicity confirmed an apparent immunodominance of the full VEINCTR-N, based on its homology with the consensus sequence of other members of the tumor necrosis factor (TNF) receptor family. The hypothesis that the high immunogenicity of this region of Fas, rather than gp120, can drive the production of anti-VEINCTR-N antibodies also was supported by the concurrent significant elevations of soluble Fas in almost all of the sera studied.

CONCLUSIONS

Our results indicate that a high release of the soluble form of Fas by T cells during the chronic immune activation of HIV-1 infection primes a humoral response against this epitope of Fas as a result of its high antigenicity. This is similar to the antibodies to tumor necrosis factor alpha (TNFalpha) receptor (R) (TNFalpha-R) that occur in response to increased levels of the soluble receptor for TNF during autoimmunity.

Nef protein induces differential effects in CD8+ cells from HIV-1-infected patients

BACKGROUND

The Nef protein of HIV-1 is suspected to play a role in the depletion of uninfected CD4+ lymphocytes that leads to AIDS. By contrast its effect on CD8+ cells, whose functions are also deregulated during HIV-1 infection, is presently unclear. Here we describe a number of derangements induced in vitro by Nef in CD8+ cells from HIV-1-infected patients.

DESIGN

Peripheral lymphocytes from 16 HIV-1+ subjects and 9 uninfected individuals were cultivated on a Nef-transfected mouse fibroblast layer exposing the carboxyl-terminal region of the viral protein on cell membrane. The cultures were then measured for both apoptosis and proliferation by subdiploid DNA content and Ki67 expression, respectively, whereas the molecular analysis of purified CD8+ cells investigated the Fas-L mRNA levels in Nef-treated CTLs. In addition, we evaluated the Nef-induced variation in the extent of CD8+/HLA-DR+ subset, which includes non cytotoxic cells secreting T-cell antiviral factor (CAF) and a soluble factor inhibiting the HIV-1 replication.

RESULTS

The viral protein induced in peripheral blood lymphocytes (PBL) a moderate tendency to proliferate, as measured by the increment of Ki67 antigen, particularly on the CD8+ subset of HIV-1 infected individuals (P < 0.05). This profile was particularly evident in cultures from patients with severe CD4+ lymphopenia and paralleled an apparent expansion of the CD8+/CD57+ suppressor cell subset. Molecular analysis of purified CD8+ cells revealed a defective expression of Fas-L mRNA in Nef-cultured CTLs, whereas the viral protein exerted a down modulatory effect on the CD8+/HLA-DR+ subset (P < 0.05), thus suggesting a potential inhibition of CAF.

CONCLUSIONS

These results support a potential role of Nef in the progression of HIV-1 infection as a number of cellular functions are affected in the CD8+ subset. In particular, the defective functions of CD8+ cells induced by the viral protein could contribute, at least partly, to the escape of HIV-1 from the immune control of these cells.

Anti-DNA and anti-nucleosome antibody affinity--a mirror image of lupus nephritis?

OBJECTIVE

To measure relative functional affinities of both IgG anti-DNA and anti-nucleosome antibodies in patients with systemic lupus erythematosus (SLE).

METHODS

Serum IgG anti-DNA antibodies were affinity purified from DNA-Sepharose columns (APAD) and tested for functional affinities using dissociation of antigen-antibody binding with diethylamine. IgG antibody affinities for nucleosomes prepared from chicken erythrocyte nuclei and apoptotic normal human leukocyte nuclei were also measured.

RESULTS

Many patients with SLE nephritis showed low IgG anti-DNA antibody affinity for both DNA and nucleosomes during clinical phases of active nephritis. Serial studies confirmed an apparent relationship between clinical bouts of active renal disease and low residual serum anti-DNA and sometimes anti-nucleosome affinity. Serial studies of patients with SLE without renal disease did not show episodes of low affinity serum anti-DNA. When APAD were compared to renal biopsy eluates, much higher affinity for DNA was found in renal eluates than in APAD in serum. Similarly, low affinity antibodies in serum were associated with high affinity anti-nucleosome antibody in renal biopsy eluates in some but not all of 10 patients with SLE studied.

CONCLUSION

Residual IgG anti-DNA antibody affinity for DNA is often low during phases of active SLE nephritis. When nephritis improves or precipitates chronic renal failure, serum anti-DNA antibody affinity increases. Measurement of anti-DNA antibody affinity may provide a useful indicator of renal disease activity.

Functional Fas-ligand expression on T cells from HIV-1-infected patients is unrelated to CD4+ lymphopenia

Recent studies have demonstrated that the expression of Fas by peripheral T cells from HIV-1+ patients is deregulated and increases the susceptibility of these cells to undergo apoptosis. Here, we show that secretion of Fas-ligand (L), the complementary agonist of Fas, is abnormally upregulated in CD4+ cells from HIV-1-infected individuals, particularly during the non-lymphopenic stages of the disease. An increase of soluble Fas-L occurred in T cell cultures from 26 patients with a number of CD4+ cells higher than 400/microliter, whereas it was almost undetectable in cultures from 21 severely lymphopenic patients (CD4+ < 200/microliter). The MTT test, cytofluorimetric analysis of cellular DNA, cytotoxicity, and proliferative assays using the Fas-transfected WC8 mouse lymphoma confirmed the cytocidal capability of T cell supernatants from non-lymphopenic patients. Double-fluorescence analysis revealed that the majority of CD4+ cells (approximately 90%) in these cultures secreted Fas-L in the presence of high intracellular gamma-interferon and low Bcl-2. In contrast, the CD8+/Fas-L+ population was comparably decreased (approximately 55%). Molecular cloning of Fas-L revealed a substantial expression of Fas-L mRNA in cells from non-lymphopenic patients compared with patients with advanced disease and healthy controls. Since CD4+ cells of Th1 phenotype are impaired during HIV-1 infection and show high cellular expression of Fas-L, it is conceivable that excess Fas-L during the early or non-lymphopenic phase of the disease increases the extent of apoptosis in these cells by the Fas/Fas-L pathway. The defective expression of the ligand in severely lymphopenic stages could be explained by exhaustion of this mechanism as the disease progresses.

Fas/Fas ligand (FasL)-deregulated apoptosis and IL-6 insensitivity in highly malignant myeloma cells

IL-6 is a growth factor which interferes in the apoptosis of malignant plasma cells. Here we explore its role in the spontaneous and Fas/FasL-regulated apoptosis of seven myeloma cell clones (MCC). MCC-2 and -7 were constitutively defective in Fas antigen in the presence of large membrane exposure of FasL, and showed a high rate of cell proliferation irrespective of the presence of IL-6. Cytofluorimetric analysis following propidium iodide (PI) staining revealed a minimal extent of spontaneous apoptosis, as in other IL-6-insensitive, though Fas-positive MCC, namely MCC-3 and -5. By contrast, a regular amplitude of apoptosis occurred in the remaining IL-6-dependent clones. Their propensity to cell death, as well as their FasL membrane expression, were promptly down-modulated by the cytokine, whereas no substantial effect was detected in IL-6-independent MCC. Furthermore, we investigated the quantitative secretion of FasL. Both [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) cytotoxicity assay and PI staining of WC8 lymphoblasts from a Fas-transfected mouse lymphoma, incubated with supernatants from MCC, showed a variable cytocidal property, thus confirming the cellular release of FasL. However, a significant elevation of FasL secretion occurred in both Fas- MCC, whereas molecular cloning and sequencing of Fas revealed the presence of a splicing variant, namely Fas Exo4,6Del, in the cDNA from both MCC-3 and -5, which were previously demonstrated to be unresponsive to Fas stimulation. Taken together, these data provide evidence that concurrence of IL-6 insensitivity and deregulation of apoptosis in myeloma cells reflects a high malignancy grade. It is suggested that the secretion of Fas splicing variants in Fas+ plasma cells, as well as the over-production of FasL in Fas- myelomas, are differential mechanisms by which myeloma cells escape host immune surveillance.

Urinary loss of immunoglobulin G anti-F(ab)2 and anti-DNA antibody in systemic lupus erythematosus nephritis

The objective of this study was to determine whether the low levels of serum immunoglobulin G (IgG) anti-F(ab)2 seen in some patients with active systemic lupus erythematosus (SLE) were directly related to the deposition of antibody with this specificity in the kidney or alternatively to the urinary loss of IgG anti-F(ab)2. Serum Levels of IgG anti-F(ab)2, anti-tetanus toxoid, and anti-ds DNA antibody were measured in parallel with urinary excretion of these same 3 antibodies in 28 patients with SLE nephritis and in 28 control patients with other forms of chronic kidney disease. Low levels of both serum IgG anti-F(ab)2 or anti-tetanus antibody appeared to correlate with increased levels of urinary loss of these same antibodies in some patients with SLE and in control subjects with kidney disease. However, urinary loss could not account for low serum levels of either IgG antibody in many subjects. Quantitative 24-hour urinary losses of IgG anti-F(ab)2 and anti-DNA were much higher in patients with SLE than in control subjects with kidney disease (P < .05), whereas amounts of IgG urinary loss of anti-tetanus were similar in patients with SLE and in control subjects. In nearly 1 third of SLE nephritis patients, 13% to 53% of total excreted urinary IgG showed anti-DNA enzyme-linked-immunosorbent assay reactivity. Urinary IgG in many patients with SLE showed both anti-DNA and anti-F(ab)2 reactivity, but dual anti-DNA/F(ab)2 specificity was more pronounced in affinity-isolated serum IgG anti-DNA or anti-F(ab)2 than in excreted urinary IgG molecules. The affinity of urinary IgG for either DNA or F(ab)2 was much lower than the same antibody activities measured either in serum or in kidney biopsy eluates. When the relative affinity of anti-DNA antibody in serum, urine, and kidney biopsy eluate was measured in parallel, the highest affinity antibody was found in kidney biopsy eluates, followed by serum antibody with urine antibody affinity showing the lowest values. These findings suggest a relative concentration of the highest affinity, doubly reactive IgG anti-DNA/F(ab)2 in SLE kidney tissues during SLE nephritis and implicate this process as an important factor in ongoing tissue damage.

The effectiveness and tolerability of epoetin alfa in patients with multiple myeloma refractory to chemotherapy

Anemia is a frequent complication of multiple myeloma, becoming chronic in patients who are resistant to chemotherapy. This randomized, parallel, controlled multicenter study (71 patients receiving concomitant chemotherapy) evaluated the efficacy and safety of epoetin alfa in improving anemia and eliminating the need for transfusions in multiple myeloma patients refractory to conventional first- or second-line chemotherapy. Forty patients were treated with subcutaneous epoetin alfa (150 IU/kg per dose, increasing to 300 IU/kg per dose, every 3 weeks) for 6 months, and 31 entered a control group. The epoetin alfa group had a significantly (P < or = 0.001) greater percentage of patients (75% vs. 21%) with increases in hemoglobin levels and/or reduced transfusion requirements. In 44 non pre-transfused patients (20 controls, 24 in the epoetin alfa group), the mean increase in hemoglobin was significantly (P < or = 0.0001) greater in the epoetin alfa group (+2.1 vs. -0.2 g/dl). Increases in hematocrit and red blood cells were also significantly (P < or = 0.0001) greater in epoetin alfa-treated patients, with corresponding reductions in transfusion requirement. In the 27 pre-transfused patients (11 controls, 16 in the epoetin alfa group), there was a trend towards reduced transfusional need in epoetin alfa-treated patients. Thus, in patients with multiple myeloma refractory to chemotherapy epoetin alfa is a well-tolerated treatment which improves anemia in non pre-transfused patients and appears to reduce transfusion need in those previously transfused.

CD8+/CD57 cells and apoptosis suppress T-cell functions in multiple myeloma

The aim of this study was to evaluate the role of CD8+/CD57+ lymphocytes in the immune dysregulation of multiple myeloma (MM). Cytofluorimetry of peripheral blood lymphocytes (PBL) purified from 39 MM patients showed an inverse relationship between the percentage of CD8+/CD57+ cells and CD4/CD8 ratio. Analysis of their activation antigens revealed that they were prevalently HLA-DR+ and Fas+. Removal of CD8+/CD57+ cells from MM PBL significantly improved cell proliferation and pokeweed mitogen (PWM)-induced polyclonal Ig production in vitro, whereas the addition of supernatants from patients' CD8+/CD57+ cell cultures to normal PBL suppressed both the PWM-driven Ig synthesis and the proliferative rate of stimulated PBL, supporting the contention that CD8+/CD57+ cells release in vitro an inhibitory factor that is directly involved in T-cell regulatory function. However, since the proliferative recovery of PWM- and phytohaemagglutinin (PHA)-stimulated MM PBL in the absence of CD8+/CD57+ lymphocytes was only partial, a dysregulated activation-induced apoptosis was anticipated. In fact, patients' PBL displayed an increased susceptibility to apoptosis and this was significantly enhanced after PWM and, even more, after PHA stimulation. Analysis of CD57 antigen expression on apoptotic or viable cells demonstrated a substantial defect of apoptosis in the CD8+/CD57+ population. Our results indicate that both the immunosuppressive effect of CD8+/CD57+ cells and the enhanced susceptibility to apoptosis of PBL could be involved in the pathogenesis of the immunodeficiency observed in this disease.

Differential risk of non-Hodgkin's lymphoma in Italian patients with primary Sjögren's syndrome

OBJECTIVE

To assess the incidence of non-Hodgkin's lymphoma (NHL) and estimate the relative risk (RR) of developing lymphoproliferative complications in a large population of Italian patients with Sjögren's syndrome (SS) and to ascertain if any difference exists between the north and centre-south of Italy.

METHODS

Differential relative risks of NHL were obtained by comparing the number of observed cases with cases identified on the basis of age-sex-time specific incidence rates extracted from regional cancer registries.

RESULTS

Among the 331 patients with SS studied, 9 cases of NHL occurred, while no lymphoid malignancy appeared in patients with overlapping connective tissue disease (secondary SS) or in males with primary SS. As the number of NHL cases identified on the basis of the rate in the cancer registries would have been 0.27, the RR is 33.3 (p < 0.001). The incidence rate of NHL in Italian patients with SS is about 5.1/1000 person-years. 5.4/1000 per year in the north of the country and 4.8/1000 per year in the centre-south. The relative risks are, respectively, 34.7 and 32.5.

CONCLUSION

Italian patients with primary SS have increased risk of developing NHL. In this group, the absence of a significant difference between the north and the centre-south of Italy contrasts with the higher incidence of NHL in the general population of northern regions and strengthens the direct connection between primary SS and NHL.

[Malignant neoplasms and AIDS. Review of the literature and critical considerations on a case of epidermoid carcinoma of the anus]

During the past few years the neoplasms defining the diagnosis of AIDS are in apparent evolution and a new distribution of specific tumors is currently reported in the literature. Besides the Kaposi's sarcoma, non-Hodgkin's lymphomas, and uterine cervical carcinoma, other malignancies are frequently diagnosed in HIV+ population, particularly during the advanced stages of the infection. The pathogenesis of such an increase of tumor diffusion is apparently related to the persistence of several herpes viruses including HHV8 and HPV whose molecular interaction with HIV may contribute to the genetic variations suitable for tumor development. The epidermoid anal carcinoma is a tumor whose appearance is increasingly recurrent in HIV+ patients, although it is not considered as an AIDS-defining neoplasia. This tumor is prevalent in HIV+ homosexual men, in particular during the full-blown immunodeficiency disease. Here we report the case of a patient whose diagnosis of AIDS was emphasized by the concurrent presence of the anal tumor.