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PubMed2006

Mycophenolic acid inhibits SLE-associated cytokine expression and promotes apoptosis of peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

AIM: To investigate the effect of the novel immunosuppressant mycophenolic acid (MPA) on cytokine production and apoptosis of the peripheral blood mononuclear cells (PBMC) of patients with systemic lupus erythematosus (SLE). METHODS: The levels of IL-10, IL-12, IFN-gamma, sFas and sFasL in the supernatants of cultured PBMC from 41 SLE patients was determined by the ABC-ELISA method. The percentage of IFN-gamma(+)IL-10(-), IFN-gamma(-)IL-10(+), and IFN-gamma(+)IL-10(+) subsets in CD4+ cells were detected by three-color flow cytometry. The percentage of apoptotic Th cells was detected by AV-FITC/PI flow cytometry. Samples from 22 sex- and age-comparable healthy people were used as normal controls. RESULTS: The levels of IL-10, IL-12, and IFN-gamma were all significantly elevated in the supernatants of cultured PBMC from SLE samples, compared with normal controls. The enhanced productions of IL-10, IL-12, and IFN-gamma by PBMC from SLE both spontaneously and stimulated by phytohaemagglutinin (PHA) were significantly reduced by MPA. The percentages of CD4(+)IFN-gamma(-)IL-10(+) and CD4(+)IFN-gamma(+)IL-10(+) cell subsets in cultured PBMC from SLE were significantly increased, but decreased when MPA was added into the culture. After being cultured in vitro for 48 h, the PBMC of SLE patients showed a higher secretion of sFasL as well as a higher percentage of apoptosis. MPA significantly increased the apoptotic percentage of SLE PBMC, but reduced the secretion of sFasL and sFas. CONCLUSION: MPA reduces the abnormal production of SLE-associated cytokines, such as IL-10, IL-12, and IFN-gamma; inhibits the increase of CD4(+)IFN-gamma(+)IL-10, CD4(+)IFN-gamma(-)IL-10(+) and CD4(+)IFN-gamma(+)IL-10(+) subset; and promotes the apoptosis of PBMC in SLE patients, which may be associated with the therapeutic mechanism of MPA for SLE.

Adolescent↗

PubMed2001

In vitro ultraviolet irradiation induces pro-inflammatory responses in cells from premorbid SLE mice.

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease, in which sunlight (especially its ultraviolet radiation (UVR)) is known to induce exacerbation of cutaneous lesions as well as systemic manifestations of the disease. The aim of this in vitro study was to investigate whether UVR (UVA, UVB) amplifies pro-inflammatory factors in cultured dermal fibroblasts (DF) or lymph node cells derived from premorbid or morbid mice from the murine SLE strains (MRL-1pr/1pr, (NZB/NZW)F1), in comparison to cells derived from normal mice from the non-SLE strains (C57BL/6, BALB/c). Our results demonstrate the following. Dermal fibroblast of premorbid SLE mice showed increased susceptibility to UVA and UVB irradiation, determined by viability assay, in comparison to those of normal mice. UVB irradiation induced an enhanced expression of ICAM-1 in such SLE derived cells, in comparison to cells of normal mice. UVA and UVB increased functional activity of LFA-1 in lymph node cells of premorbid SLE mice and not in normal controls. UVB irradiation induced increased production and secretion of pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha) in DF of premorbid SLE mice, in comparison to normal controls. The enhanced pro-inflammatory responses to UVR were also observed in experiments conducted with cells derived from morbid SLE mice. In conclusion, the pro-inflammatory proneness detected in the premorbid stage of murine SLE could be of major importance in SLE pathogenesis. Furthermore, it suggests that the autoimmune inflammatory process in vivo, triggered initially by immune complex deposition, could be further amplified by UVR.

Animals↗

PubMed2000

Preface and overview: genetics of SLE; a sine qua non for identification.

Clinical manifestations of systemic lupus erythematosus (SLE) are extremely diverse and variable, mainly because SLE is a multi-factorial disease. Variable combinations of contributing genes at multiple loci in individual patients probably result in diverse disease phenotypes. Genes that predispose to SLE are undoubtedly related to key events in pathogenesis, and may involve a variety of genes in immune system. These genes are currently unidentified, mostly because of the complexity of multi-factorial inheritance. Recently, the application of the polymerase chain reaction and the availability of maps of microsatellites have facilitated a genome-wide scan to define the number and locations of genes for complex traits. However, extensive genetic heterogeneities and polymorphisms and complex modes of inheritance of disease phenotypes have delayed completion of a genome-wide analysis of susceptibility loci for human SLE. Since many SLE-susceptibility genes show low penetrance, several hundred affected sibpairs are assumed to be necessary to show linkages for many of the contributing loci. In this respect, studies of polymorphisms and functions of candidate genes suggested based on studies on murine models may contribute to studies on SLE patients and their relatives. Major genetic loci have been mostly identified in SLE-prone mouse strains. Nevertheless, identity of natures, functions and roles in the pathogenesis of SLE remains undetermined. Considering the possibility of clustering of susceptibility loci in a particular chromosomal interval, the final goal for identification of susceptibility genes will largely depend on the generation of mutant SLE-prone mice with homologous recombination of the potential target gene. Extensive reviews collected here are expected to form the basis for identification of target genes and for clarification of the genetic mechanisms underlying SLE.

Animals↗

PubMed1999

[Antibodies to various phospholipids in SLE patients with primary antiphospholipid syndrome].

Antiphospholipid antibodies (aPL) represent a heterogeneous population reacting with negatively charged, less frequently neutral phospholipids and/or phospholipid-binding serum proteins. The study was made of antibodies to a wide spectrum of phospholipids: to negatively charged phospholipids such as phosphatide acid (aPA), cardiolipin (aCL), phosphatidylcholine (aPS), phosphatidylinositol (aPI), phosphatidylglycerol (aPG) and to neutrally charged phospholipid--phosphatidylcholine (aPC)--in 54 patients with systemic lupus erythematosus (SLE) and 29 patients with primary antiphospholipid syndrome (PAPS). The test for lupus anticoagulant (LAC) was also made. aPL in SLE patients free of antiphospholipid syndrome were detected in 61, 36 and 9% (aPC, aPS and aPA, aCL, respectively). aPI and aPG did not exceed normal values. 81% of SLE patients with antiphospholipid syndrome were LAC positive and 88% aPL positive. 60, 53, 44, 40, 13 and 17 were positive to aPC, aPA, aPS, aCL, aPG and aPI, respectively. Among patients with PAPS, the highest positivity was by LAC, occurrence of the other aPL was the same as in SLE patients with antiphospholipid syndrome. aCL, aPA, aPC, aPS, aPG and aPI were found in 55, 52, 41, 38, 31 and 21% of cases, respectively. In clinical manifestations of antiphospholipid syndrome and negative tests for LAC and aCL it is advisable to make tests for aPS and aPC. aPC occur in SLE patients more frequently than the other aPL: in 63% of SLE patients free of antiphospholipid syndrome and in 60% of SLE patients with this syndrome. Antibodies to other phospholipids, but not to cardiolipin, were present in SLE + APS in half of the cases but in SLE + PAPS in one third of the patients. Occurrence of aCL in the serum of SLE + PAPS patients is associated with the presence of antibodies to any other phospholipid irrespective of the charge. The severity of vascular changes did not correlate with the number of aPL variant found in the serum.

Adolescent↗

PubMed2002

Differentiation of RNP- and SM-antibody subsets in SLE and MCTD patients by a new ELISA using recombinant antigens.

Connective tissue diseases often have overlapping clinical features and laboratory abnormalities. The distinctiveness of mixed connective tissue disease (MCTD) as an entity is of scientific interest and practical importance. In order to discriminate between MCTD and SLE patients we used a newly developed, commercially not available ELISA with recombinant antigen expressed in Baculovirus infected cells. This ELISA detects antibodies against RNP and Sm in complex as well as the subsets U1-snRNP 68 kDa, RNP-A, RNP-C (RNP), Sm-BB' and SS-D. We analyzed 66 RNP-positive consecutive patients prediagnosed as SLE or MCTD/overlap-syndrome. 45/66 patients were found to be U1-snRNP-68 kDa positive (27 SLE, 18 MCTD), 51/66 RNP-A [36,15] and 44/66 RNP-C [31,13]. 35/66 had antibodies against Sm-BB' (30 SLE, 5 MCTD), 10/66 against Sm-D (all SLE). 28/66 were found to be U1-snRNP-68 kDa and Sm-BB' positive (23 SLE, 5 MCTD), while 8/66 where U1-snRNP-68 kDa and Sm-D positive (all SLE). The combination of antibodies against 68 kDa, Aand C was exclusively observed in 6 MCTD patients, while the combination against 68 kDa, A, C, Sm-BB' and Sm-D was restricted to 8 patients with SLE. The antibody combination to 68 kDa, A, C and Sm-BB' was also found in 11/20 SLE patients with major organ involvement. In SLE and MCTD, determination of subsets of antibodies against Ul-snRNP-68 kDa and Sm-complex allows a differentiation of patient subgroups with more definite diagnoses and potential prognostic impact.

Adult↗

PubMed1991

[Clinical course and prognosis in SLE patients with pulmonary hypertension: a comparative study with primary pulmonary hypertension].

Recently pulmonary hypertension (PH) has been recognized as one of life threatening complications which determine the prognosis of patients with systemic lupus erythematosus (SLE). Clinical aspects and pathology in patients with SLE complicated by PH (SLE-PH) have been reported to have a close similarity to those in patients with primary pulmonary hypertension (PPH), the prognosis of which is very poor in general. However, the long-term prognosis for patients with SLE-PH is not clear yet. Mainly because of some technical limitations for determining the severity of the PH, long-term follow-up studies have been inconclusive. In this study, 7 patients with SLE-PH and 6 patients with PPH were studied by using two-dimensional echocardiography. The interventricular septal curvature (R) was measured from the parasternal short axis view and the reciprocal value (1/R) was applied as a severity index of the PH. In 4 patients with SLE-PH and 6 with PPH, pulmonary arterial pressure was measured by cardiac catheterization concomitantly. There were no significant differences in 1/R and pulmonary arterial pressure between the two groups when PH was diagnosed for the first time. In the PPH group, the mean period of follow-up study was 25.3 months and all of the patients died during that period. In SLE-PH group, the mean period of follow-up study was 50.6 months, and only 3 patients (43%) died during that period. No patients in the PPH group showed improvement in 1/R, but 3 patients with SLE-PH improved in 1/R during a long follow-up period (60, 96 and 103 months respectively). Thus, the prognosis for SLE-PH was better than that for PPH, and there were some differences in the course and worsening behavior of PH in SLE-PH compared with that in PPH during the long-term follow-up study with reference to the echocardiographic investigation using 1/R value.

Adolescent↗

PubMed1978

Loss of suppressor T-lymphocyte function in patients with systemic lupus erythematosus (SLE).

Immunological reactivity in patients with SLE was studied in vitro trinitrobenzene sulphonate (TNP) specific antibody formation by peripheral blood lymphocytes. Lymphocytes from patients with SLE could produce an increased number of TNP-specific plaque-forming cells (PFC), while no such response could be seen in normal controls. Co-culture of lymphocytes from active SLE patients and normal controls was performed with TNP-Horse red blood cells (TNP-HRBC). The number of PFC by B lymphocytes from active SLE patients was suppressed by T lymphocytes from normal controls. On the other hand, the number of PFC by B lymphocytes from normal controls was increased by T lymphocytes from active SLE patients. Co-culture of lymphocytes from identical twins discordant for SLE was also performed, and the same results were obtained. We further examined the effects of Con A on antibody formation. Con A-treated T lymphocytes from a normal control markedly suppressed TNP-specific PFC by peripheral lymphocytes from active SLE patients. However, Con A-treated T lymphocytes from an active SLE patient did not suppress TNP-specific PFC by lymphocytes from another active SLE patient. These results suggest that active SLE patients showed a loss of suppressor T-lymphocyte function.

Adolescent↗

PubMedDate not supplied

Cellular control of antinuclear antibody production. Anti-dsDNA and anti-Sm plaque forming cells in SLE patients and normal individuals.

The in vitro response of lymphocytes to dsDNA, Sm, and Pokeweed Mitogen (PWM) and the role of monocytes in the control of this response were studied in 21 SLE and 14 healthy individuals. Specific hemolytic plaque assays were used to enumerate peripheral blood B lymphocytes secreting anti-dsDNA and anti-Sm antibodies. After 7 days in tissue culture without stimulation, anti-dsDNA or anti-Sm Plaque Forming Cells (PFC) were observed in 75% of SLE patients and 45% of normals. PWM, dsDNA, and Sm stimulation raised the levels of anti-dsDNA PFC in 25%, 37%, and 83% of SLE cultures respectively, and in all but one normal culture. PWM and dsDNA induced a decrease in anti-dsDNA PFC in 50% and 62% of SLE cultures. This suppressive effect was mainly exerted on spontaneous high producers of anti-dsDNA PFC. Monocyte depletion from cultures resulted in a decrease in PFC formation in all normals studied and in 7 SLE cultures. In 2 SLE cultures with no stimulation and one dsDNA stimulated culture, the number of anti-nuclear PFC increased after monocyte depletion. In cocultures of allogeneic, HLA-DR identical mononuclear cells, dsDNA pulsed SLE monocytes appeared more efficient than pulsed normal monocytes in helping to generate anti-dsDNA PFC. SLE lymphocytes responded less well than normals to dsDNA. These results suggest that: nuclear antigens may act as stimulators or suppressor of the specific autoimmune response, depending on the immune status of the SLE patient; and that abnormalities in both monocyte and lymphocyte responses lead to the excessive secretion of anti-dsDNA and anti-Sm antibodies by SLE B lymphocytes.

Adult↗

PubMed2001

Autoimmunity to the p53 protein is a feature of systemic lupus erythematosus (SLE) related to anti-DNA antibodies.

The induction of anti-DNA autoantibodies in systemic lupus erythematosus (SLE) patients is problematic because mammalian DNA is poorly immunogenic at best. Here we demonstrate a chain of connected antibodies in SLE patient sera that could account for the induction of anti-DNA antibody, and possibly for some of the pathogenic features of SLE. We now report that SLE patients, in addition to anti-DNA, produce antibodies to the carboxy-terminal domain of the tumour suppressor molecule p53; this p53 domain recognizes damaged DNA. Hence, these anti-p53 antibodies could mimic damaged DNA immunologically. Indeed, SLE sera do contain anti-idiotypic antibodies to a prototypic anti-p53 antibody. Moreover, SLE anti-DNA antibodies also recognize this type of anti-p53 antibody. Indeed, binding of affinity-purified anti-DNA both to DNA and to the anti-p53 antibody could be blocked by a p53 peptide derived from the DNA-binding domain. This mimicry of the p53 DNA-binding domain by the SLE anti-DNA antibodies is functional: activation of the p53 molecule could be inhibited by such anti-DNA antibodies. Thus, anti-DNA antibodies may arise in SLE patients by a chain of idiotypic autoimmunity centered around p53 autoimmunity. The SLE anti-DNA and anti-p53 antibodies can functionally block p53 activation, and so could affect apoptosis.

Antibodies, Antinuclear↗

PubMed1975

Impaired cell-mediated immunity in systemic lupus erythematosus (SLE). A controlled study of 23 untreated patients.

Cell-mediated immunity was evaluated in 23 patients with systemic lupus erythematosus (SLE) prior to therapy and in 23 control subjects. The patients with SLE who had moderate to severe disease activity had significantly fewer positive delayed skin tests to streptokinase-streptodornase (SK-SD) and Candida than the control subjects, and a higher frequency of anergy than either the control subjects or the patients with mild SLE. Significant impairment of lymphocyte transformation to all common antigens tested was found in patients with SLE as compared to both normal subjects and control subjects with disease. Phytohemagglutinin response was reduced in patients with SLE as compared to normal subjects but not to the control subjects with disease. Lymphocyte transformation responses to SK-SD and Candida were also significantly lower in patients with moderate to severe SLE as compared to patients with mildly active SLE. Primary immune response to keyhole limpet hemocyanin (KLH) was impaired in patients with SLE as measured by lymphocyte transformation and total KLH antibody, but not 2-mercaptoethanol resistant antibody. The data indicate defective T-cell function in SLE, and suggest that the impairment relates in part to disease activity.

Adolescent↗

PubMed1986

Suppressor cell function and anti-DNA antibody idiotypes in the serum of SLE patients and their first-degree relatives.

Sixteen-six (16/6) is a major cross-reactive idiotype of monoclonal anti-DNA antibodies, which was derived from the fusion of lymphocytes of a patient with systemic lupus erythematosus (SLE). Antibodies with the 16/6 idiotype (16/6 Id) are increased in the sera of patients with SLE and deposited in their gomeruli and skin. Since stimulated lymphocytes from healthy persons have the capacity to produce 16/6 Id, the mechanisms controlling its expression in health and their possible failure in SLE are of considerable interest. A defect in suppressor cell function was found in a high proportion of patients with SLE and in some of their first-degree relatives. Suppressor cell function in 15 SLE patients and in 53 relatives was compared with the level of 16/6 Id as well as with immunoglobulin levels and anti-DNA antibodies. Ten of 15 SLE patients and 26 of 53 first-degree relatives had increased serum 16/6 levels, which was found in only 1 of 35 healthy controls and household members. Of the 10 SLE patients with increased 16/6, six had a suppressor cell defect (P less than 0.1). Among the 26 first-degree relatives with elevated 16/6 Id levels, 12 had associated suppressor defect and in only two cases was a suppressor cell defect unaccompanied by increased 16/6 (P less than 0.005). For the group of 18 patients and relatives showing concomitant suppressor cell defect and increased 16/6, a correlation was found between the severity of the suppressor cell defect and the level of 16/6 Id in the serum. The increased 16/6 in the relatives was not associated with hypergammaglobulinemia or with measurable anti-DNA activity in the serum. We conclude that the suppressor cell defect in relatives of SLE patients is often associated with increased expression of antibodies with the 16/6 idiotype. However, additional mechanisms are involved in the regulation of 16/6 Id and the development of clinical SLE, since increased 16/6 was commonly found in the presence of a normal suppressor T-cell function.

Antibodies, Antinuclear↗

PubMed2006

Proinflammatory cytokines (TNF-alpha and IL-6) in Egyptian patients with SLE: its correlation with disease activity.

BACKGROUND: Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by a wide variety of autoantibodies, some of which are pathogenic. In recent years it has become more evident that the polyclonal B cell activation in SLE is T-cell dependent. The stimulation of the autoantibody producing B cells is likely mediated by the TH2 subtype of T cells producing IL-4, IL-5, IL-6 and IL- 10, whereas the TH1 subtype secreting IL-2 and IFN-gamma predominates in cell-mediated immune response. Tumor Necrosis Factor (TNF-alpha) is both a proinflammatory and an immunoregulatory cytokine. TNF-alpha has differential effects on B cells, on T cells and on dendritic cells as well as on the process of programmed cell death. Understanding how the immune system integrates the pleiotropic properties of TNF-alpha is a challenge, particularly so in diseases like SLE. Meanwhile the role of IL-6 in the pathogenesis of SLE is controversial. OBJECTIVE: To investigate whether serum levels of TNF-alpha and IL-6 is higher in Egyptian patients with SLE than healthy control volunteers and its correlation with the clinical activity in patients with different activity scores as measured by Systemic Lupus Erythmatosus Disease Activity Index (SLEADI). METHODS: Sixty individuals (40 patients with Systemic lupus Erythmatosus and 20 healthy control volunteers) were the subject of this study, they were subjected to thorough clinical examination, laboratory investigations, their clinical disease activity was scored according to SLEDAI, and serum sampling was obtained for TNF-alpha and IL-6 levels assay. Renal biopsy was carried out and examined by light microscopy by a pathologist blinded with the clinical activity. RESULTS: The mean level of TNF-alpha was (766.95+/-357.82Pg/ml) for patients with active disease while it was (314.01+/-100.87Pg/ml) for those with inactive disease and (172.7+/-39.19Pg/ml) for the healthy control group. The difference was statistically significant (P=.002). The mean level of IL-6 was (135.4+/-54.23Pg/ml) for patients with active disease while it was (47.33+/-18.61Pg/ml) for those with inactive disease and (21.15+/-10.99Pg/ml) for the healthy control group. The difference was statistically significant (P=.002). A significant correlations between TNF-alpha and IL-6 serum levels and the SLEDAI score was observed (r=.743 and .772, respectively). CONCLUSION: Serum TNF-alpha and IL-6 are sensitive markers of SLE disease activity. They may be useful independent markers for prediction of SLE disease activity and to differentiate normal subjects from those having SLE. Possible therapeutic implications in the treatment of SLE in the future deserve wide scale trials.

Adolescent↗

PubMed1997

Reduced protein tyrosine phosphatase (PTPase) activity of CD45 on peripheral blood lymphocytes in patients with systemic lupus erythematosus (SLE).

To disclose the mechanism of aberrant function of peripheral blood lymphocytes (PBL) in SLE, we focused on the catalytic function of CD45, and determined the CD45 PTPase activity in SLE patients. The sample population consisted of 32 SLE patients with different disease activity. PTPase activity of cell lysates immunoprecipitated by anti-CD45 MoAb was assayed against phosphotyrosine analogue PNPP, followed by measuring the release of para-nitro phenol at 410 nm. CD45 PTPase activity of PBL was significantly decreased in SLE patients, compared with that of normal controls and patients with systemic sclerosis (964 +/- 265, 1202 +/- 172, 1210 +/- 125, respectively; SLE versus normal, P<0.05). It was correlated with SLE Disease Activity Index (SLEDAI) score (r = 0.597, P = 0.0006), but not with the dose of prednisolone (r = 0.214, P = 0.2657), indicating that CD45 PTPase activity became reduced when the disease was active, but it was not affected by prednisolone. Moreover, it was not corrected by in vitro culture with or without stimulation. The expression of CD45 on PBL was comparable between normal and SLE, raising a possibility that it may be due to aberrant regulation of catalytic function of CD45 in SLE. Given the evidence that tyrosine phosphorylation of cellular proteins by tyrosine kinases and phosphatases is one of the key biochemical events in the signal transduction pathway, the decreased CD45 PTPase activity in SLE may account for the defective signal transduction via TCR/CD3, leading to dysregulated effector function of the lymphocytes.

Adult↗

PubMed2000

IL-10 stimulates production of platelet-activating factor by monocytes of patients with active systemic lupus erythematosus (SLE).

IL-10 displays modulatory properties on the synthesis of platelet-activating factor (PAF), a potent inflammatory mediator of vascular injury. Despite the fact that IL-10 is considered to be an anti-inflammatory cytokine, IL-10 levels correlate with disease activity in SLE. Moreover, in SLE IL-10 is unable to exert its immunosuppressive and anti-inflammatory effects. We have investigated the ability of IL-10 to stimulate PAF production from monocytes of SLE patients. Spontaneous and IL-10-stimulated PAF production by peripheral blood monocytes was measured in active (n = 13) and inactive (n = 14) SLE patients and in 15 normal control subjects. We observed that monocytes derived from patients with active SLE, but not from controls or inactive SLE, spontaneously produced significant amounts of PAF. Moreover, IL-10 enhanced the synthesis of PAF from monocytes of active SLE patients only. IL-10-induced PAF production correlated with the severity of the disease and with the extent of proteinuria. These results indicate that IL-10 only stimulates the synthesis of PAF from monocytes of SLE patients when immunologically active, suggesting that IL-10 may possess a paradoxical proinflammatory effect in SLE by promoting the production of PAF, a secondary mediator of inflammation.

Adult↗

PubMed2001

Anti-CD3-induced and anti-Fas-induced apoptosis in systemic lupus erythematosus (SLE).

Disturbances in apoptosis or in the clearance of apoptotic material might result in increased presentation of autoantigens which could be relevant to the pathogenesis of SLE. Data concerning defects in apoptosis in SLE are conflicting. To determine whether intrinsic defects in apoptosis induction occur in SLE irrespective of disease activity, we examined anti-CD3 and anti-Fas-induced apoptosis in vitro in SLE patients with inactive disease. Isolated peripheral blood lymphocytes (PBL) from 13 SLE patients and 14 healthy controls were incubated with anti-CD3, and, subsequently, after up-regulation of membrane Fas following anti-CD3 incubation, with anti-Fas. Expression of Fas and levels of apoptosis as detected by annexin V and propidium iodide staining were assessed by flow cytometry before and after the respective incubations. Fas expression on freshly isolated lymphocytes of SLE patients was increased whereas levels of circulating apoptotic cells were comparable between patients and controls. Stimulation with anti-CD3 resulted in up-regulation of membrane Fas in patients and in controls. In vitro induction of apoptosis by anti-CD3 as well as by anti-Fas occurred both in SLE patients and controls, and was higher in SLE patients after incubation with anti-CD3 as well as with anti-Fas. We conclude that Fas expression and in vitro induction of apoptosis are increased in SLE even in the absence of disease activity.

Adult↗

PubMed2002

Evidence for a susceptibility gene (SLEH1) on chromosome 11q14 for systemic lupus erythematosus (SLE) families with hemolytic anemia.

Hemolytic anemia is a forme fruste of systemic lupus erythematosus (SLE), being observed months or even years before the onset of other clinical manifestations in some patients. We hypothesized that hemolytic anemia in those SLE-affected patients would identify a group of SLE pedigrees that share a high degree of genetic homogeneity. From 160 multiplex SLE pedigrees, we sought evidence for linkage in 35 (16 African-American, 17 European-American, and 2 Hispanic) who had at least one SLE-affected patient with hemolytic anemia. Significant linkage was present at 11q14 in the 16 African-American pedigrees, yielding a maximum two-point logarithm of odds (LOD) score of 4.5 at D11S2002. The segregation pattern of SLE in these African-American pedigrees suggested a dominant mode of inheritance and, when maximized across penetrance and disease allele frequencies, produced a multipoint LOD of 4.7. Multipoint analysis yielded a multipoint heterogeneity LOD score of 3.6 (alpha = 0.63), again with maximum LOD at D11S2002. Finally, markers typed 7 centimorgans to either side of D11S2002 achieved LOD scores of 3 or better by using the maximized model, supporting linkage to 11q14. Clearly, pedigree ascertainment based on select clinical manifestations is an important tool, capable of revealing otherwise cryptic genetic linkages in complex genetic diseases. Thus, we show strong evidence for an SLE susceptibility gene, SLEH1, near D11S2002 in African-American pedigrees multiplex for SLE that have at least one SLE-affected patient with hemolytic anemia.

Anemia, Hemolytic↗

PubMed2006

MERTK polymorphisms associated with risk of haematological disorders among Korean SLE patients.

OBJECTIVE: The MER receptor tyrosine kinase (MERTK) gene is critical for the efficient clearance of apoptotic cells and has implications for inflammation and autoimmune diseases such as systemic lupus erythematosus (SLE). We investigated the genetic polymorphisms in MERTK to evaluate it as a potential candidate gene for a host genetic study of SLE and clinical manifestations in patients with SLE. METHODS: By resequencing the coding and flanking regions of the MERTK gene in 24 unrelated Koreans, 37 polymorphisms were identified. Based on gene position, minor allele frequency and inter-single-nucleotide polymorphism (SNP) linkage disequilibrium, six of these polymorphisms were selected for subsequent genotyping and association analysis with the risk of SLE and haematological disorders in 350 Korean SLE patients and 330 controls. RESULTS: Although no significant associations with the risk of SLE were found, logistic regression analyses revealed that variants +465C > G (P = 0.05) and +130215insdelT (P = 0.0005) were significantly associated with decreased risk of leucopenia in SLE patients. Further, +465C > G, +95616G > A, +123157A > G and the haplotype ht1 also showed significant associations (P = 0.006-0.05) with a decreased risk of lymphopenia in SLE patients. CONCLUSION: Our findings suggest that polymorphisms in MERTK might be one of the genetic risk factors for presenting leucopenia and lymphopenia in SLE patients.

Adolescent↗

PubMed1993

Elevated platelet-associated IgG in SLE patients due to anti-platelet autoantibody: differentiation between autoantibodies and immune complexes by ether elution.

The level of platelet-associated IgG (PAIgG) is reported to be elevated in patients with systemic lupus erythematosus (SLE). However, the nature of PAIgG is unclear. We have investigated whether the PAIgG of SLE consists of anti-platelet autoantibodies or immune complexes (IC). The PAIgG values measured by flow cytometry were elevated in 11/25 patients with SLE. 3/6 SLE patients with thrombocytopenia had a high level of PAIgG (the mean fluorescence intensity > 10). We used an ether elution technique to determine whether elevated PAIgG consists of anti-platelet antibodies or IC. Preliminary experiments showed that the eluates prepared from platelets sensitized with anti-HPA-4a antibody reacted with normal platelets, while the eluates prepared from platelets sensitized with heat-aggregated IgG or model IC failed to react with normal platelets. These results indicate that the reactivity of eluates can distinguish between platelet-bound antibody and IC. We applied this technique to analysis of the PAIgG of SLE platelets. The eluates from SLE platelets (the mean fluorescence intensity > 10) reacted with normal platelets, indicating that the PAIgG of SLE platelets has the nature of antiplatelet autoantibodies. Furthermore, we investigated the target antigens which bind PAIgGs of SLE, using the direct immunoprecipitation procedure and modified antigen capture ELISA (MACE). Both methods identified GPIIb/IIIa as the target antigens. We conclude that the ether elution technique can distinguish between anti-platelet antibodies and IC, and that the PAIgGs of SLE with a high PAIgG value and thrombocytopenia have the nature of anti-platelet autoantibodies.

Antigen-Antibody Complex↗