Search PubMed⌕ Search

Biomedical subjects

D Alarcón-Segovia

Publications and source records attributed to D Alarcón-Segovia.

At least 19 recordsLinked to original sources
PubMed2004

Both risk alleles for FcgammaRIIA and FcgammaRIIIA are susceptibility factors for SLE: a unifying hypothesis.

The aim of this study was to analyze in families with SLE for the presence of linkage and the structure and transmission of haplotypes containing alleles for the low-affinity Fcgamma receptors. The Fcgamma receptor polymorphisms FcgammaRIIA-131R/H, FcgammaRIIIA-176F/V and FcgammaRIIIB-NA1/2 and a polymorphism in the FcgammaRIIB gene were genotyped with RFLP, allele-specific PCR or pyrosequencing. Individual SNPs and haplotypes were tested for linkage in multicase families and for association using contingency tables, transmission disequilibrium test and affected family-based control groups in Swedish and Mexican single-case families. No linkage or association could be detected using the FcgammaR polymorphisms in the multicase families. However, an association was found for both FcgammaRIIA-131R and IIIA-176F alleles in the single-case families, but not for IIIB or IIB. Allelic association to SLE was found for a haplotype that included both risk alleles, but not in haplotypes where only one or the other was present. We propose that FcgammaRIIA-131R and FcgammaRIIIA-176F are both risk alleles for SLE transmitted primarily, but not exclusively on a single major haplotype that behaves functionally in a situation similar to that of compound heterozygozity.

Alleles↗
PubMed2004

Heterogeneity of antibodies to beta2-glycoprotein 1 from patients with systemic lupus erythematosus.

We studied antibodies to beta2-glycoprotein 1 (anti-beta2GP1) from 72 patients with systemic lupus erythematosus (SLE) with or without antiphospholipid syndrome (APS) or with or without anticardiolipin antibodies (aCL). Fifteen patients had APS and positive antiphospholipid antibodies [clinical APS(+)/aPL(+)], 12 patients had APS, negative serum IgG and IgM aCL, antiphosphatidylethanolamine, anti-phosphatidylserine and no lupus anticoagulant [clinical APS(+)/ aPL(-)]. A third group included 16 patients without APS but high aCL levels [clinical APS(-)/ aPL(+)]. In a fourth group we studied 29 patients without clinical manifestations of APS or aCL [clinical APS(-)/aPL(-)]. One hundred anticardiolipin and VDRL-negative normal sera were studied as controls. IgG antibodies to cardiolipin proper in a bovine beta2GP-free system, to human beta2GP1 immobilized on cardiolipin or to human beta2GP1 alone were detected in all sera by ELISA using irradiated and nonirradiated plates from two manufacturers. Sera from APS(+)/aPL(+) patients showed IgG binding to CL, CL + beta2GP1 and beta2GP1 in irradiated and nonirradiated plates. APS(+)/ aPL(-) sera had more significant IgG binding to beta2GP1 than normal controls when studied in both irradiated or nonirradiated plates (P = 0.001). This binding was inhibited by solid-phase cardiolipin in a dose-dependent manner. Sera from the APS(-)/aPL(+) subgroup had comparable IgG activity in both the CL and CL + beta2GP1 assays, while no anti-beta2GP1 activity was detected in these sera. Sera from the clinical APS(-)/aPL(-) patients were negative in the three ELISA systems. Antibodies to human beta2GP1 from SLE patients recognize various epitopes. Those from APS(+)/ aPL(+) patients appear to react with an epitope boosted by cardiolipin in addition to another one present in the native protein. In contrast, anti-beta2GP1 from patients with APS(+)/aPL(-) are blocked by cardiolipin, suggesting that their epitope is the phospholipid-binding site.

Adult↗
PubMed2004

Prevalence and factors associated with fibromyalgia in Mexican patients with systemic lupus erythematosus.

In total, 189 consecutive women diagnosed with SLE were evaluated using the ACR 1990 criteria for fibromyalgia. Patients were classified into three subgroups. The fibromyalgia group (FM) included patients experiencing pain on palpation in at least 11 of the 18 tender points examined, as well as having a history of widespread pain for at least three months. Patients who were noted to have pain in fewer than four quadrants with less than 11 of 18 tender points were considered to have regional pain (RP). All patients who did not meet criteria for either FM or RP were classified as having no pain (NP). Measurement of SLE disease activity, sleep complaints, depression, fatigue severity and health status were performed. Only 18 of the SLE patients (9.5%) (95% CI 5.3-14%) fulfilled the ACR criteria for the classification of FM. Of the patients, 106 (56.1%) fulfilled criteria for RP and had a number of tender points of 5.4 +/- 3.4, and the rest of the patients (34.4%) had no tenderness at specific tender point sites. Age, body mass index, educational level and disease duration were comparable between the groups. FM and RP groups had different patterns of symptoms prevalence, with dysmenorrhea being more distinctive for FM. Sleep disturbances were more severe in the FM than in the RP group. Daytime complaints such as sleepiness, fatigue and depression were similar for RP and FM groups, but patients with FM reported more disability. Fibromyalgia is not common in Mexican patients with SLE and has a different pattern of symptoms in RP and NP patients. These data add evidence that ethnicity can play an important role in FM manifestations.

Adolescent↗
PubMed2004

Neuroendocrine dopaminergic regulation of prolactin release in systemic lupus erythematosus: a possible role of lymphocyte-derived prolactin.

Prolactin (PRL) secretion by the pituitary is under the control of dopamine. Hyperprolactinemia has been found in patients with systemic lupus erythematosus (SLE) and seems to be associated with clinical activity. T-lymphocytes express PRL and those from SLE patients appear to secrete more PRL than controls. In this study, immuno-(RIA) and bio-(BIO) assayable PRL in both serum and culture media of peripheral blood mononuclear cells (PBMNC) from SLE and control subjects were evaluated in the basal state and in response to 10 mg oral administration of metoclopramide, a dopamine receptor antagonist. Prolactin size heterogeneity in serum and culture media and PRL gene transcription in PBMNC were also studied. Basal serum RIA-PRL, BIO-PRL and the BIO/RIA ratio were similar in both groups. The serum BIO-PRL response after metoclopramide was higher than RIA-PRL in SLE, and this increment was also greater than in control subjects. PBMNC from SLE subjects secreted and produced more BIO-PRL. After metoclopramide, secretion and production of PRL increased only in PBMNC from control women and not in those from SLE patients. Our results demonstrated an increased central dopaminergic tone in SLE and suggest that lymphocyte-derived PRL might contribute to alter the functional activity of the hypothalamic dopaminergic system in SLE attempting to maintain serum PRL within a physiological range.

Adult↗
PubMed2003

Immunoregulatory defects in patients with systemic lupus erythematosus in clinical remission.

Little is known about the immune system of patients with systemic lupus erythematosus (SLE) during periods of silent disease. To address this issue we analysed lymphoid populations andcytokine production of mononuclear cells obtained from SLE patients in remission. We studied 43 patients with inactive disease, 10 with active disease and 30 controls. Remission was defined as at least 1 year during which lack of clinical disease activity permitted withdrawal of all treatment. Remission length ranged from 1 to 30 years. Flow cytometry and ELISA were used to study lymphoid populations (CD4, CD8 and CD19) and cytokine production (IL-2, 4, 10, 12 and 18). Patients with short remission periods (up to 15 years) exhibited an increased percentage of B cells; production of IL-2, IL-10 and IL-12 was decreased; production of IL-18 was increased. Interestingly, patients from groups with long time of inactive disease had corrected most alterations, but had an impaired IL-18 expression. IL-12 production correlated strongly with the length of the remission period (r = 0.7565). The immune system of patients with inactive lupus has partially corrected the disturbances present during disease activity. This is accomplished gradually, sometimes until counter-regulatory alterations are developed. This may allow patients to remain without disease activity.

Adolescent↗
PubMed2003

Prophylaxis of the antiphospholipid syndrome: a consensus report.

Hypothetical circumstances that may require prophylaxis for a potential antiphospholipid syndrome (primary prophylaxis), or in some instances when there already had been some manifestations ofthe syndrome (secondary prophylaxis), were presented to a panel of experts for their consideration on potential prophylactic intervention. These were subsequently presented to the participants in the First International Consensus on Treatment of the Antiphospholipid Syndrome. In most instances there was consensus in adding low dose aspirin, an exception being aspirin allergy when other antiaggregants could be used in nonpregnant subjects. General measures to prevent thrombosis and other vasoprotective actions should also be provided. Higher risk of fetal loss or thrombosis called for anticoagulation with coumadin in nonpregnant subjects or subcutaneous low molecular weight heparin in pregnant ones. When indicated, prophylaxis of the antiphospholipid syndrome should be provided in systemic lupus erythematosus patients who are being treated for their disease. In no instance should corticosteroids or immunosuppresants be given as prophylactic of an antiphospholipid syndrome.

Anticoagulants↗
PubMed2003

Improvement in health-related quality of life in systemic lupus erythematosus patients enrolled in a randomized clinical trial comparing LJP 394 treatment with placebo.

In a 76-week, randomized controlled trial, patients received 100 mg LJP 394 or placebo weekly for 16 weeks followed by three 12-week treatment cycles of 50 mg LJP 394 or placebo weekly each separated by eight-week periods when no therapy was administered. Health-related quality of life (HRQOL) was assessed using SF-36 at baseline, 16 weeks and every 12 weeks thereafter. Analyses populations included intent to treat (ITT) (n = 179) and patients with high-affinity anti-dsDNA antibody binding (HA): 157/179; 85% active, 90% placebo. In the ITT population, there were improvements in role emotional (RE) (+7.3 versus -8.2), social functioning (SF) (+4.3 versus +0.7), and role physical (RP) (+11.3 versus +6.0) domains in the active treatment group when compared with placebo, with similar changes observed in the HA population. In 37 patients with data pre- and post-renal flares, those receiving LJP 394 reported stabilization or improvement in all but one domain compared with deterioration in all domains with placebo. Changes in RE domain scores following a flare differed by 22.7 points between the two treatment groups, favouring LJP 394 treatment. Patients receiving LJP 394 reported stable or improved HRQOL with active treatment following renal flares compared with deterioration in placebo. Differences between treatment groups in RE and SF domains are clinically important and were replicated irrespective of the protocol population analysed.

Double-Blind Method↗
PubMed2001

Class II allele and haplotype frequencies in Mexican systemic lupus erythematosus patients: the relevance of considering homologous chromosomes in determining susceptibility.

The aim of the present study was to determine the relevant major histocompatibility complex (MHC) class II alleles in the genetic susceptibility to systemic lupus erythematosus (SLE) in Mexican Mestizo patients. We examined the gene and haplotype frequencies of the HLA-DRB1, DQA1 and DQB1 alleles by polymerase chain reaction-sequence-specific oligonucleotide probes in 81 Mexican SLE Mestizo patients and 99 ethnically matched controls. We found a significantly increased frequency of the HLA-DRB1*0301 (p(c) = 0.031, odds ratio = 2.63) allele and significantly decreased frequencies of the DRB1*0802 (p(c) = 0.035) and DRB1*1101 (p(c) = 0.037) alleles in the SLE group. Haplotype analysis showed increased frequencies of DRB1*0301-DQA1*0501-DQB1*0201 (p(c) = 0.017, odds ratio = 2.97), and decreased frequency of DRB1*0802-DQA1*0401-DQB1*0402 (p(c) = 0.034) in SLE patients. The most frequently detected haplotypes in SLE patients showed different haplotypic combinations in the homologous chromosome from those found in controls. Thus, the combinations detected in SLE patients were either not detected in the control group or infrequently found. The results suggest that the DRB1*0301 is the principal class II allele associated with the genetic susceptibility to SLE in Mexican patients and that the presence of a specific haplotype of the homologous chromosome in patients with DRB1*0407-DQA1*03-DQB1*0302 and DRB1*1501-DQA1*0102-DQB1*0602 haplotypes could have an additive effect on the susceptibility to the disease. Finally, the low frequency of the DRB1*0301 and DRB1*1501 alleles in the control population suggests that the genetic admixture between Mexican Indians and Caucasian populations was an event that could have increased the risk of Mexicans to develop SLE.

Alleles↗
PubMed2001

Novel facts about an old marker: the LE cell.

For more than fifty years, lupus erythematosus (LE) cells were believed to result from in vitro opsonization of bare nuclei by serum antinuclear antibodies and their ultimate phagocytosis by neutrophils. Twenty years ago, we described that certain antinuclear antibodies could enter into viable cells, and later on, it was proved that penetration of anti-DNA antibodies into cells results in protracted active cell death. Recent findings indicate that the material engulfed by LE cells are apoptotic blebs as residuals of cells dying after penetration of anti-DNA antibodies. These observations not only change the interpretation of the presence of the LE cell phenomenon, but also stress the potential pathophysiological role of antibodies to intracellular antigens in autoimmune diseases.

Active Transport, Cell Nucleus↗
PubMed2001

Penetration of autoantibodies into living cells, 2000.

The formerly prevalent concept that intact autoantibodies could not penetrate into viable cells has been defeated by a large amount of experimental findings and clinical observations that indicate otherwise. The penetration of autoantibodies into living cells seems to participate in the pathogenesis of diverse autoimmune diseases, but it may also play a physiological role in healthy individuals. Although the fine mechanisms of the phenomenon remain to be elucidated, the potential use of penetrating autoantibodies as vectors to deliver molecules into cells, with diverse therapeutic purposes, has gained growing interest during the last few years.

Animals↗
PubMed2001

The future of treatment for systemic lupus erythematosus.

The future promises good news for the treatment of systemic lupus erythematosus, some of which can already be foreseen. Increased knowledge on genes that participate in the predisposition, pathogenesis, pharmacogenetics of, and protection against this disease may permit intervention at this level. Also, better understanding about the role of sex hormones has allowed trials of weak androgens or prolactin inhibitors. New immunomodulators or immunosuppressors may enable more precise treatment at the immunoregulatory level, and greater knowledge on the disturbance of circuits has already provided hints and even allowed trials of anti-interleukin-10 antibodies, an IL-10 decreasing agent, tolerance-induction strategies or intervention at the level of T cell co-stimulation, as well as immune ablation with subsequent stem cell transplantation. Autoantibodies can be removed, controlled by means of anti-idiotypes, which are blocked from reaching their target antigen or uncoupled from the tissues they have reached. All these treatment strategies will gradually become decanted in order to achieve the optimal treatment of SLE, which may tum out to be its cure.

Adjuvants, Immunologic↗
PubMed2000

Fine mapping of the SLEB2 locus involved in susceptibility to systemic lupus erythematosus.

We have previously reported linkage of systemic lupus erythematosus to chromosome 2q37 in multicase families from Iceland and Sweden. This locus (SLEB2) was identified by linkage to the markers D2S125 and D2S140. In the present study we have analyzed additional microsatellite markers and SNPs covering a region of 30 cM around D2S125 in an extended set of Nordic families (Icelandic, Swedish, and Norwegian). Two-point linkage analysis in these families gave a maximum lod score at the position of markers D2S2585 and D2S2985 (Z = 4.51, PIC = 0.65), by applying a "model-free" pseudo-marker linkage analysis. Based on multipoint linkage analysis in the Nordic families, the most likely location of the SLEB2 locus is estimated to be in the interval between D2S125 and the position of markers D2S2585 and D2S2985, with a peak multipoint lod score of Z = 6.03, assuming a dominant pseudo-marker model. Linkage disequilibrium (LD) analysis was performed using the data from the multicase families and 89 single-case families of Swedish origin, using the same set of markers. The LD analysis showed evidence for association in the single-case and multicase families with locus GAAT3C11 (P < 0.0003), and weak evidence for association was obtained for several markers located telomeric to D2S125 in the multicase families. Thirteen Mexican families were analyzed separately and found not to have linkage to this region. Our results support the presence of the SLEB2 locus at 2q37.

Base Sequence↗
PubMed2000

Clinical and biologic effects of anti-interleukin-10 monoclonal antibody administration in systemic lupus erythematosus.

OBJECTIVE: To evaluate the safety and clinical efficacy of administering an anti-interleukin-10 (anti-IL-10) monoclonal antibody (mAb) to systemic lupus erythematosus (SLE) patients with active and steroid-dependent disease. In addition, we sought to assess the effects of in vivo IL-10 neutralization on biologic markers of SLE. METHODS: Treatment consisted of 20 mg/day intravenous administration of an anti-IL-10 murine mAb (B-N10) for 21 consecutive days, with a followup period of 6 months. Six patients were studied. RESULTS: Treatment was safe and well tolerated. All patients developed antibodies against B-N10. Cutaneous lesions and joint symptoms improved in all patients beginning during B-N10 administration and continuing to month 6. The SLE Disease Activity Index decreased from a mean +/- SEM of 8.83+/-0.91 on day 1 to 3.67+/-0.67 on day 21 (P = 0.001), 1.50+/-0.84 at month 2, and 1.33+/-0.80 at month 6 (P<0.001). At the end of followup, the disease was clinically inactive in 5 of the 6 patients. Prednisone administration was decreased from a mean +/- SEM of 27.9+/-5.7 mg/day on day 1 to 9.6+/-2.0 mg/day at month 6 (P<0.005). Activity of immune and endothelial cells rapidly decreased, as assessed by the early evolution of several biologic markers. CONCLUSION: This is the first report of IL-10 antagonist administration to humans. The study shows the involvement of IL-10 in the pathogenesis of SLE, and indicates that the use of IL-10 antagonists may be beneficial in the management of refractory SLE.

Adolescent↗
PubMed2000

Vasculitis in the connective tissue diseases.

Vasculitides in the setting of connective tissue diseases are generally thought to be infrequent and relatively little is written about them. They are, however, important both because they may pose diagnostic and therapeutic challenges and affect prognosis. In each of the connective tissue diseases, vasculitis can present in various clinical and pathologic forms adding to their diagnostic and therapeutic difficulties. This article reviews recent information on the frequency, characteristics, and possible pathogenic mechanisms of the vasculitides occurring in patients with the main connective tissue diseases.

Comorbidity↗