Zev Sthoeger

CD24 is a marker for human breast carcinoma.

CD24 is a small, mucin-type glycosylphosphatidylinositol-linked cell surface molecule expressed by neutrophils, pre B lymphocytes and certain human tumor cell lines. CD24 has been identified as a ligand for P-selectin in both mouse and human cells. We previously reported that the P-selectin-CD24 binding pathway is important for the binding of the breast carcinoma cell line KS to platelets and the rolling of these cells on endothelial P-selectin. In the present study we have analyzed the expression of CD24 on human breast carcinoma cell lines and on fresh breast carcinoma specimens using the CD24-specific antibody ML-5. Our study clearly demonstrates that CD24 is abundantly expressed on cell lines and fresh tissues of breast carcinomas. We find a differential expression of CD24 in breast carcinomas (cytoplasmic pattern) versus benign breast lesions (apical pattern). Moreover, the intensity of CD24 expression increases with the histological grade of the tumor. Thus, CD24 expression might be a useful marker for human breast carcinoma and play a role in facilitating metastasis by the interaction between tumor cells and platelets or endothelial cells.

Beneficial effects of the anti-oestrogen tamoxifen on systemic lupus erythematosus of (NZBxNZW)F1 female mice are associated with specific reduction of IgG3 autoantibodies.

Background: Sex hormones have been shown to influence the immune system and to modify the course of autoimmune disorders. Objective: To examine the effects of the oestrogen antagonist tamoxifen on the course of systemic lupus erythematosus (SLE) in (NZB×NZW)F1 mice. Methods: Groups of 8 week old (NZB×NZW)F1 female mice were treated with tamoxifen (800 μg/mouse; twice a week) or with double distilled water for four months. Mice were evaluated monthly for the presence of autoantibodies directed against DNA and nuclear extract (NE) by enzyme linked immunosorbent assay (ELISA). White blood cells and thrombocytes were quantified by a cell counter and proteinuria by combistix kit. At 6 months of age, all mice that did not die spontaneously were killed and evaluated for the presence of glomerular immune deposits by indirect immunofluorescence assay. IgG isotypes of autoantibodies in the mouse sera and glomeruli were determined by γ chain specific antibodies. Results: Tamoxifen treatment significantly reduced autoantibody production directed against either NE or DNA. The latter reduction was mainly in autoantibodies of the IgG3 isotype. Furthermore, tamoxifen had significant beneficial effects on the course of SLE in (NZB×NZW)F1 mice. At 6 months of age, 40% of the untreated mice died spontaneously, whereas all the tamoxifen treated mice were still alive. All untreated mice showed severe thrombocytopenia and persistent proteinuria, with diffuse glomerular immune deposits of IgG2a and IgG3 isotypes in their kidneys. In contrast, the tamoxifen treated mice had a normal number of thrombocytes and only minimal proteinuria. Moreover, glomerular immune deposits were detected in <40% of the tamoxifen treated mice. The latter were mainly of the IgG2a but not of the IgG3 isotype. Conclusion: The results clearly show the remarkable therapeutic effects of tamoxifen on SLE of (NZB×NZW)F1 female mice and suggest that these beneficial effects are related to the specific reduction of IgG3 autoantibodies.

Activity of matrix metalloproteinase-9 is elevated in sera of patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the increased production of autoantibodies and by systemic clinical manifestations and damage to multiple organs. The aim of the present study was to analyse matrix metalloproteinase (MMP)‐9 activity in sera of patients with active and inactive SLE in order to evaluate its role in the pathogenesis and course of the disease, as well as its diagnostic value. We measured activity levels of MMP‐9 and MMP‐2, using both gel zymography and activity assay kits, in sera of 40 SLE patients and of 25 healthy controls. We found that MMP‐9 activity, but not MMP‐2 activity, is significantly elevated in the sera of SLE patients compared with sera samples of healthy controls. High activity levels of MMP‐9 were determined in sera of 68% of the SLE patients. Elevated levels of MMP‐9 were correlated with the presence of discoid rash, Raynaud phenomenon, pneumonitis, mucosal ulcers and anti‐phospholipid antibodies. Changes in activity levels of MMP‐9, but not of MMP‐2, were observed in sera of the same patient at different periods of the disease course. High levels of MMP‐9 did not correlate with disease activity index (SLEDAI, BILAG) in female patients, but correlated with SLE activity in the group of male patients. The results of the present study suggest that MMP‐9 plays a role in the pathogenesis of SLE.

Treatment of lupus patients with a tolerogenic peptide, hCDR1 (Edratide): immunomodulation of gene expression.

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by dysregulation of cytokines, apoptosis, and B- and T-cell functions. The tolerogenic peptide, hCDR1 (Edratide), ameliorated the clinical manifestations of murine lupus via down-regulation of pro-inflammatory cytokines and apoptosis, up-regulation of the immunosuppressive cytokine TGF-beta, and the induction of regulatory T-cells. In the present study, gene expression was determined in peripheral blood mononuclear cells of 9 lupus patients that were treated for 26 weeks with either hCDR1 (five patients), or placebo (four patients). Disease activity was assessed by SLEDAI-2K and the BILAG scores. Treatment with hCDR1 significantly down-regulated the mRNA expression of the pathogenic cytokines IL-1beta, TNF-alpha, IFN-gamma, and IL-10, of BLyS (B-lymphocyte stimulator) and of the pro-apoptotic molecules caspase-3 and caspase-8. In contrast, the treatment up-regulated in vivo gene expression of both TGF-beta and FoxP3. Furthermore, hCDR1 treatment resulted in a significant decrease in SLEDAI-2K (from 8.0+/-2.45 to 4.4+/-1.67; P=0.02) and BILAG (from 8.2+/-2.7 to 3.6+/-2.9; P=0.03) scores. Thus, the tolerogenic peptide hCDR1, immunomodulates, in vivo, the expression of genes that play a role in SLE, consequently restoring the global immune dysregulation of lupus patients. Hence, hCDR1 has a potential role as a novel disease-specific treatment for lupus patients.

High circulating levels of free interleukin-18 in patients with active SLE in the presence of elevated levels of interleukin-18 binding protein.

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies particularly to nuclear antigens and by an abnormal production of proinflammatory cytokines. In the present study, we measured the levels of the proinflammatory cytokine IL-18 and its natural inhibitor, the IL-18 binding protein (IL-18BP), in sera of SLE patients at various stages of the disease. This is the first study to present IL-18BP levels in sera of SLE patients as well as the calculated, biologically active, free IL-18 concentrations that are most probably more relevant to the pathology of SLE. Sera from 48 unselective SLE patients (total of 195 samples) were obtained longitudinally with a mean follow-up period of 11.1 +/- 8.9 years and were compared to sera from 100 healthy volunteers. Circulating levels of IL-18, IL-18BP and free IL-18 in the SLE patients were significantly higher than the levels of healthy controls (5 fold, 6 fold and 3 fold for IL-18, IL-18BP and free IL-18, respectively) and correlated with disease activity as scored by SLEDAI-2K. Furthermore, these levels during active disease (SLEDAI-2K > or = 6) were higher compared to the levels measured in the sera of the same patients during remission or during mild disease (SLEDAI-2K 0-5). The high levels of IL-18 and IL-18BP in sera of active SLE patients suggest their possible role in the pathogenesis and course of the disease. However, despite the elevated levels of IL-18BP during active disease, free IL-18 remained more than 2 fold higher than the levels in healthy controls suggesting a potential benefit of administration of exogenous IL-18BP as a novel therapeutic approach for active SLE.

Anticardiolipin autoantibodies in serum samples and cryoglobulins of patients with chronic hepatitis C infection

OBJECTIVE Chronic hepatitis C virus (HCV) has been linked to extrahepatic autoimmune phenomena. In addition, a variety of autoantibodies are found in patients with HCV. The prevalence, nature, and clinical significance of anticardiolipin (aCL) autoantibodies in serum samples of patients with HCV were therefore investigated. PATIENTS AND METHODS A prospective study of 48 consecutive patients with chronic HCV with no evidence of previous hepatitis B virus (HBV) infection or any other autoimmune disorder. Thirty patients with HBV and 50 healthy volunteers matched for age and sex served as control groups. Anticardiolipin antibodies in the serum samples and cryoprecipitates were measured by a sensitive enzyme linked immunosorbent assay (ELISA). The β2 glycoprotein I (β2-GPI) dependency was determined by carrying out aCL assays in the presence or absence of fetal calf serum samples. RESULTS High levels of IgG aCL antibodies were detected in serum samples of 21/48 (44%) patients with HCV. These autoantibodies showed no β2-GPI dependency. The control groups had much lower levels of aCL antibodies (20% in the patients with HBV and none in the normal volunteers). Cryoprecipitates from four patients with HCV (three aCL positive; one aCL negative) were further isolated. In two of the three aCL positive patients, specific cardiolipin reactivity was shown in the cryoprecipitates. The group of patients with HCV and aCL antibodies in their serum showed significantly higher total IgG levels, a higher incidence of antinuclear antibodies, and viraemia (HCV RNA) than the aCL negative patients. None of the patients with HCV and aCL antibodies showed any clinical manifestations related to those autoantibodies. CONCLUSIONS This study clearly shows a high prevalence of IgG aCL antibodies in the serum of patients with HCV and the localisation of these antibodies in some cryoprecipitates. The role of these autoantibodies on the course of HCV infection and their clinical significance has not yet been determined.

High α-defensin levels in patients with systemic lupus erythematosus

Innate immunity plays a role in systemic lupus erythematosus (SLE). Our objective was to determine the levels of defensins, which are antimicrobial and immunomodulatory polypeptides, in SLE. Sera from SLE patients and healthy controls were tested for pro‐inflammatory human β‐defensin 2 (hBD‐2) and for α‐defensin human neutrophil peptide 1 (HNP‐1). hBD‐2 could not be detected by enzyme‐linked immunosorbent assay (ELISA) and its mRNA levels were low in SLE patients and similar to those found in controls. In contrast, the mean α‐defensin level in the sera of all SLE patients (11·07 ± 13·92 ng/μl) was significantly higher than that of controls (0·12 ± 0·07 ng/μl). Moreover, 60% of patients demonstrated very high serum levels (18·5 ± 13·36 ng/μl) and 50% showed elevated gene expression in polymorphonuclear cells. High α‐defensin levels correlated with disease activity, but not with neutrophil count. Thus, activation and degranulation of neutrophils led to α‐defensin secretion in SLE patients. Given the immunomodulatory role of α‐defensins, it is possible that their secretion may activate the adaptive immune system leading to a systemic response.

Modulation of autoreactive responses of peripheral blood lymphocytes of patients with systemic lupus erythematosus by peptides based on human and murine anti-DNA autoantibodies

Two peptides, based on the sequences of the complementarity‐determining regions (CDR) 1 and 3 of a pathogenic murine monoclonal anti‐DNA autoatibody that bears the 16/6 idiotype (Id), were shown to either prevent or treat an already established systemic lupus erythematosus (SLE) in two murine models of lupus. Two additional peptides based on the human monoclonal anti‐DNA, 16/6 Id were synthesized. This study was undertaken in order to investigate the ability of the CDR‐based peptides to immunomodulate SLE‐associated responses of peripheral blood lymphocytes (PBL) of SLE patients. PBL of 24 of the 62 SLE patients tested proliferated in vitro following stimulation with the human 16/6 Id. Peptides based on the CDRs of both the human and murine anti‐DNA autoantibodies inhibited efficiently and specifically the 16/6 Id‐induced proliferation and IL‐2 production. The latter inhibitions correlated with an up‐regulated production (by 2·5–3·5‐fold) of the immunosuppressive cytokine, TGF‐β. Overall, the results of our study demonstrate that the CDR‐based peptides are capable of down‐regulating in vitro autoreactive T cell responses of PBL of SLE patients. Thus, these peptides are potential candidates for a novel specific treatment of SLE patients.

Angiotensin-converting enzyme inhibitor-induced angioedema.

Angiotensin-converting enzyme inhibitors (ACE-I) are widely used, effective, and well-tolerated antihypertensive agents. The mechanisms by which those agents act can cause side effects such as decreased blood pressure, hyperkalemia, and impaired renal function. ACE-I can induce cough in 5%-35% and angioedema in up to 0.7% of treated patients. Because cough and angioedema are considered class adverse effects, switching treatment to other ACE-I agents is not recommended. Angioedema due to ACE-I has a low fatality rate, although deaths have been reported when the angioedema involves the airways. Here, we review the role of bradykinin in the development of angioedema in patients treated with ACE-I, as well as the incidence, risk factors, clinical presentation, and available treatments for ACE-I-induced angioedema. We also discuss the risk for recurrence of angioedema after switching from ACE-I to angiotensin receptor blockers treatment.

High prevalence of systemic lupus erythematosus in 78 myasthenia gravis patients : A clinical and serologic study

Objective:The objective of this study was to define the prevalence of systemic lupus erythematosus (SLE) in patients with myasthenia gravis (MG). Methods:Seventy-eight MG patients recruited unselectively from Israeli MG database were evaluated by medical history, physical examination and serology (ANA at 1:100 and anti-ds-DNA at 1:10 dilution) for the presence of SLE, which was defined by the presence of four or more American College of Rheumatology diagnostic criteria. Results:Thirty-one (40%) of our patients were males and 47 (60%) were females. Their mean age at time of the study was 51.5 ± 14.5 years. Forty patients (51%) had an early-onset disease (<40 years); 90% had generalized and 10% had limited ophthalmic MG. Significant titers of ANA and ds-DNA autoantibodies were observed in 38.5% and 19.2% of the patients. In six (7.7%), a definitive diagnosis of SLE was established (MG was first diagnosed; there was no association with previous thymectomy), three of them revealed lupus-related neurologic manifestations. All six patients were females with an early onset generalized MG. Conclusion:High prevalence of SLE and lupus-related autoantibodies exist in female MG patients. Thus, MG patients should be evaluated for the coexistence of SLE, and assessment for MG is suggested in lupus patients with unexplained muscular weakness.