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H M Moutsopoulos

Publications and source records attributed to H M Moutsopoulos.

At least 109 records · Page 6Linked to original sources
PubMed1999

Recurrent pregnancy loss and autoantibody profile in autoimmune diseases.

OBJECTIVE: To explore the association of non-organ-specific autoimmune responses against three distinct Ro antigen-related reactivities (Ro52, Ro60, p57) with a history of pregnancy loss in women with autoimmune disorders. Materials and methods. Seventy unselected anti-Ro/SSA-positive women were studied in a retrospective cohort study. Forty anti-Ro/SSA-positive women were age matched to an equal number of women with autoimmune disorders who were anti-Ro/SSA negative in a case-control study. The association of reactivities against three distinct antigen specificities (Ro52, Ro60, p57) with recurrent pregnancy loss was investigated. Independence and modification of these associations from the effect of antithyroglobulin, antithyroid peroxidase and anticardiolipin antibodies were also examined. RESULTS: In the cohort study, reactivity against each of the three antigen specificities (Ro52, Ro60, p57) was independently associated with a history of recurrent pregnancy loss. In the case-control study, the effects were still independent and were not modified when other autoantibodies were considered. In particular, the number of reactivities against Ro52, Ro60 and p57 peptides, and the presence of antithyroglobulin antibodies, were independent predictors of recurrent pregnancy loss (odds ratios 3.35 per each additional reactivity and 5.54 in the presence of antithyroglobulin; P=0.002 and 0.025, respectively). CONCLUSIONS: In women with autoimmune disorders, a history of recurrent pregnancy loss is independently associated with reactivity against each of the three antigen specificities (Ro52, Ro60, p57) and also with the presence of antithyroglobulin antibodies, suggesting that cumulative autoimmune responses against these non-organ-specific and organ-specific antigens correlate with the risk of stillbirth and spontaneous abortion.

Abortion, Habitual↗
PubMed1999

Microvascular abnormalities in Sjögren's syndrome: nailfold capillaroscopy.

OBJECTIVE: To describe microvascular abnormalities by nailfold capillaroscopy in patients with primary Sjögren's syndrome (SS) with or without Raynaud's phenomenon (RP) and those with anticentromere antibodies (ACA). METHODS: Forty patients with SS (14 without RP, 16 with RP, 10 with ACA), 20 patients with scleroderma (SSc) (10 with limited and 10 with diffuse disease) (disease control group) and 40 healthy controls (control group) were evaluated by nailfold capillaroscopy. RESULTS: Capillaroscopic abnormalities in SS ranged from non-specific findings (crossed capillaries) to more specific findings (confluent haemorrhages and pericapillary haemorrhages) or scleroderma-type findings. SS patients with RP presented capillary abnormalities in higher frequency than patients without RP. The majority of SS patients with ACA (80%) presented scleroderma-type findings. CONCLUSION: Nailfold capillaroscopy can be used as a simple non-invasive method to evaluate the microvascular abnormalities in SS patients, especially in those with RP and those with ACA.

Capillaries↗
PubMed1999

Lung involvement in primary Sjögren's syndrome is mainly related to the small airway disease.

OBJECTIVE: To evaluate lung involvement in patients with primary Sjögren's syndrome. METHODS: Sixty one consecutive, non-smoking patients, 58 women and three men, were evaluated clinically, physiologically, and radiologically. A bronchial and/or transbronchial biopsy was performed on 13 of the patients. Physiological data were compared with that of a control group of 53 healthy non-smoking subjects matched for age and sex. RESULTS: In 41% of the patients the main symptom was dry cough. Physiological studies revealed that the patients presented significantly lower expiratory flow values (% pred) when compared with those of the control group: the forced expiratory volume in one second (FEV1) (mean (SD)) was 96% (16) v 111% (13) (p < 0.0001), the maximal expiratory flow at the 50% of the vital capacity (MEF50) was 72% (24) v 103% (17) (p < 0.0001), and the maximal expiratory flow at the 25% of the vital capacity (MEF25) was 49% (25) v 98% (20) (p < 0.0001). No significant difference was noted for the carbon monoxide diffusion value (% pred), between patients and controls. Blood gases were evaluated in 44 patients: mild hypoxemia was observed, and the alveolo-arterial oxygen difference (P(A-a)O2) correlated significantly with MEF50 (r = 0.35, p < 0.01) and MEF25 (r = 0.33, p < 0.01) values. Chest radiography showed mild, interstitial-like changes in 27 patients while slightly increased markings were present in 21. High resolution computed tomography of the lungs was performed in 32 patients (four with a normal chest radiograph, six with suspected interstitial pattern, 19 with apparent interstitial pattern, and three with hyperinflation) and revealed predominantly wall thickening at the segmental bronchi. All positive findings by computed tomography derived from the patients with abnormal chest radiographs. Transbronchial and/or endobronchial biopsy specimens in 10 of the 11 sufficient tissue samples revealed peribronchial and/or peribronchiolar mononuclear inflammation, while interstitial inflammation coexisted in two patients. CONCLUSION: The airway epithelia seem to be the main target of the inflammatory lesion of the lung in patients with primary Sjögren's syndrome. It seems to be common, subclinically leading to obstructive small airway physiological abnormalities.

Adult↗
PubMed1999

Sjögren's syndrome. Autoimmune epithelitis.

Sjögren's syndrome is a chronic autoimmune disorder characterized by mononuclear cell infiltration proximally to epithelial cells of exocrine glands. In recent years, several studies have tried to address the function of the components of the immunopathologic lesion in Sjögren's syndrome. The majority of the mononuclear infiltrating cells are CD4 positive T lymphocytes (60-70%) whereas B cells constitute one fourth of the infiltrating cells. Macrophages and natural killer cells are poorly represented in the lesion. Epithelial cells of minor salivary glands of patients with Sjögren's syndrome express proinflammatory cytokines (IL-1 beta, IL-6), protooncogenes (c-myc) and costimulatory molecules (B71, B72). The destruction of epithelial cells of Sjögren's syndrome patients is probably due to activation of several apoptotic pathways since epithelial cells express different apoptosis related molecules such as Fas, FasL, Bax, while mononuclear cells express Bcl-2, Perforin and Granzymes. Finally epithelial cells seem to exert a regenerative effort since they express trefoil proteins (pS2). The above properties give epithelial cells a significant role in the pathophysiology of the syndrome but the exact events which drive the immune system towards an autoimmune reaction remain obscure.

Apoptosis↗
PubMed1998

A major Sm epitope anchored to sequential oligopeptide carriers is a suitable antigenic substrate to detect anti-Sm antibodies.

A sensitive, highly reproducible, solid-phase enzyme immunoassay (ELISA), was developed in order to investigate whether the synthetic heptapeptide PPGMRPP-a major epitope of the Sm autoantigen-anchored in five copies to a sequential oligopeptide carrier (SOC), [(PPGMRPP)5-SOC5] is a suitable antigenic substrate to identify anti-Sm/antibodies. Sera with different autoantibody specificities [45 anti-Sm, 40 anti-U1RNP, 40 anti-Ro (SSA)/La(SSB) positive, 21 Antinuclear antibody positive, but negative for antibodies to extractable nuclear antigens (ANA + /ENA - ) and 75 normal human sera, ANA negative] and 75 sera from patients with rheumatoid arthritis (RA) were tested for anti-(PPGMRPP)5-(SOC)5 reactivity in order to evaluate the specificity and sensitivity of the method to detect anti-Sm antibodies. RNA immunoprecipitation assays for the detection of anti-Sm and anti-U1RNP antibodies and counter immunoelectrophoresis (CIE) for the detection of anti-Ro(SSA) and anti-La(SSB) antibodies were used as reference techniques. The sensitivity of the method was 98% and the specificity was 68% for the determination of anti-Sm antibodies, while for the determination of anti-Sm and/or anti-U1RNP reactivity (antibodies to snRNPs) the corresponding values were 82% and 86%, respectively. In a comparison of the above assay with an ELISA, using Sm/U1RNP purified complex as immobilized antigen it was shown that the sensitivity of the anti-Sm/U1RNP ELISA in detecting anti-snRNPs was 74%; in addition sera with anti-Sm antibodies gave higher binding in the anti-(PPGMRPP)5-(SOC)5 ELISA compared with anti-Sm/U1RNP ELISA. Intra- and inter-assay precision was measured on four sera with reactivities extending into a wide range of absorbance values showed that the intra-assay coefficient of variation (CV%) ranged from 2.7 to 6 and the inter-assay CV% ranged from 9 to 14.5. These results indicate that the PPGMRPP peptide anchored to a pentameric SOC as a carrier is a suitable antigen for detecting anti-Sm antibodies and that the above ELISA is a rapid, reproducible and valuable screening method to test anti-Sm/U1RNP reactivities.

Antibodies, Antinuclear↗
PubMed1998

Antibodies to beta 2-glycoprotein-I: urea resistance, binding specificity, and association with thrombosis.

The aim of the present study was to evaluate the urea resistance and binding characteristics of anti-beta 2-glycoprotein I (anti-beta 2GPI) antibodies using standard anticardiolipin (aCL) and anti-beta 2GPI enzyme immunosorbent assays (ELISAs). Sera from patients with antiphospholipid syndrome (APS) (n = 22) and non-APS (n = 24), positive in a standard aCL ELISA, were tested in an anti-beta 2GPI ELISA performed in polystyrene-irradiated ELISA plates. Urea resistance aCL and anti-beta 2GPI ELISAs were performed by measuring the ability of antibodies to recognize antigen in the presence of 2 M urea. The serum dilution after urea treatment (D) expressed as a percentage of the serum dilution without urea treatment (D(o)) corresponding to the same optical density was defined as residual activity (RA = 100 D/D(o)). The higher the RA, the higher the resistance of the antibodies to urea. APS compared to non-APS sera had higher aCL binding (absorbance values ranging between 0.180 and 1.400; median, 0.717 vs 0.120-1.273; median, 0.250, respectively; P < 0.004). Six APS patients' sera had low aCL levels but they expressed RA > or = 30%. Anti-beta 2GPI antibodies were detected in 15 of 22 APS vs 3 of 24 non-APS patients (P < 0.03); RA > or = 30% was detected in 15 of 22 APS vs 1 of 23 non-APS patients (P < 0.004). Using a CL affinity column, antibodies were purified from three APS anti-beta 2GPI negative and three non-APS anti-beta 2GPI-positive patients and tested in a aCL ELISA, using highly purified bovine serum albumin (BSA) as a blocking agent (modified ELISA); reactivity was not detected in two APS and one non-APS sera. On the contrary, the reactivity of the purified antibodies was high when beta 2GPI was incubated with CL in the ELISA plates; thus some anti-beta 2GPI negative sera from APS patients recognized the CL/beta 2GPI complex, rather than CL or beta 2GPI alone. In conclusion, anti-beta 2GPI antibodies are common in the APS patients, but a number of such patients recognize the CL/beta 2GPI complex and not CL or beta 2GPI. Antibodies to either beta 2GPI or the CL/beta 2GPI complex derived from APS sera present a high resistance to urea. Anti-beta 2GPI antibodies of low urea resistance exist in a minority of non-APS patients with autoimmune disease.

Antibodies, Antiphospholipid↗
PubMed1998

The value of synthetic linear epitope analogues of La/SSB for the detection of autoantibodies to La/SSB; specificity, sensitivity and comparison of methods.

In a previous study it was shown that La/SSB contains four linear epitopes, p147-154, p291-302, p301-318 and p349-364. The aim of the present study was to investigate the value of the synthetic epitope analogues of the La/SSB autoantigen for the detection of antibodies to La/SSB, in comparison with recombinant La and fragments of this protein. A total of 122 sera with anti-La/SSB activity, from patients with primary Sjögren's syndrome (pSS) or systemic lupus erythematosus (SLE), were tested in various peptide-based assays. In addition, 62 sera from pSS or SLE patients with other autoantibody specificities and 95 sera from healthy individuals were used as controls. The autoantibody specificity was identified by counter immunoelectrophoresis and immunoblot. The peptide-based ELISA assays presented sensitivities ranging from 78% to 88-8% and specificities from 69% to 94-3%. Dot blot assays exhibited sensitivities ranging from 93-6% to 97%, but remarkably lower specificities from 56% to 88%. The most sensitive and specific peptide 349GSGKGKVQFQGKKTKF364 was synthesized and attached on a tetramer sequential oligopeptide carrier SOC4 and used for immunoassay development. Assays based on the recombinant native La protein, the La-C terminal (215 aa), and the N-terminal of La with a mutation at base pair 640 (nine adenines instead of eight) were also developed and compared with the SOC4 peptide-based assay. Of anti-La-positive sera, 88.1% were reactive with both the synthetic peptide SOC4-(349-364aa) and the recombinant La protein. Eighty-three percent of sera were reactive with the La N-terminus and 67.8% of sera were reactive with the La C-terminus. Using sera that were anti-Ro-positive but anti-La-negative, 37% were reactive with the recombinant protein, 26% with the La N-terminus, 33% with the La C-terminus and only 11 % with the synthetic peptide. Our results suggest that the synthetic peptide epitopes exhibit high sensitivity and specificity for the detection of anti-La/ SSB antibodies in ELISA and dot blot techniques. The peptide SOC4-(349-364aa) has the same sensitivity for the detection of anti-La/SSB antibodies as the recombinant protein.

Amino Acid Sequence↗
PubMed1998

Modes of epithelial cell death and repair in Sjögren's syndrome (SS).

We evaluated possible modes of epithelial cell destruction and restoration in minor salivary gland biopsies from patients with SS. Minor salivary gland biopsies from 10 primary Sjögren's syndrome (pSS) patients and eight control individuals were evaluated by immunohistochemical staining for the expression of apoptosis-related molecules, substances released by activated cytotoxic T cells, as well as proteins involved in epithelial cell repair. The results were analysed by computer screen analysis and they were expressed as average percentages. Apoptosis-promoting molecules, Fas antigen and Fas ligand were observed in ductal and acinar epithelial cells as well as in infiltrating mononuclear cells of minor salivary glands from SS patients in comparison with control biopsies. Bax protein, which acts as a death-promoter message, was expressed in the ductal and acinar epithelial cells and in mononuclear infiltrating cells of SS patients compared with control individuals, while Bcl-2, an inhibitor of apoptosis, was primarily found in the lymphocytic infiltrates. In situ DNA fragmentation assay (TUNEL) revealed that epithelial cells were apoptotic in patients with SS compared with control subjects. Immunohistochemical staining for perforin and granzyme B, released from granules of activated cytotoxic lymphocytes, revealed their presence in lymphocytic infiltrates of patients with SS compared with control biopsies. pS2, a member of the trefoil protein family which functions as promoter of epithelial cell repair and cell proliferation, was expressed in epithelial cells in biopsies from SS patients. These studies suggest that the functional epithelium of minor salivary glands in patients with SS appears to be influenced by both intrinsic and extrinsic mechanisms of destruction, while a defensive mechanism of epithelial restoration seems to be active.

Apoptosis↗
PubMed1998

Structural, molecular and immunological properties of linear B-cell epitopes of Ro60KD autoantigen.

Antibodies to Ro60KD protein are found with high frequency in sera from patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS). Two major epitopes of the Ro60KD antigen, the TKYKQRNGWSHKDLLRSHLKP (169-190) and the ELYKEKALSVETEKLLKYLEAV (211-232), were synthesized and their antigenic and structural properties were studied. Using a large panel of SLE and pSS patients' sera, it was found that the anti-Ro60KD reactivity of both Ro60KD epitopes is rather limited (approximately 45%), although they retain their original disease specificity. The epitope p.169-190 possessed sequence similarity with the peptide RPDAEYWNSQKDLLEQKRGR, shared in the beta-chain of different HLA-DR molecules, among them the HLA-DR3 (which is associated with anti-Ro/Sjögren's syndrome A (SSA) response in patients with SLE). The antigenicity of the HLA-DR3 RPDAEYWNSQKDLLEQKRGR peptide was found to be similar to the 169-190 homologous Ro60KD epitope, recognized mainly by SLE sera. Structural studies showed that the 211-232 Ro60KD epitope exhibits pronounced helical characteristics, while the 169-190 epitope and the HLA-DR3 homologous peptide possess a somewhat lower percentage of alpha-helix. A beta-folded structure was identified in the latter two peptides. Although the diagnostic value of the reported Ro60KD epitopes seems to be rather limited, correlations with other ribonucleoprotein epitopes (La/Sjögren's syndrome B, Ro52KD) may prove complementary to each other and valuable in clinical use. The ordered structure of the HLA-DR3 homologous peptide, exposed to the autoantibody binding, may offer an initiative in further investigation of the role of the HLA haplotypes, associated with the anti-Ro/SSA response, in the autoimmune stimulus.

Alanine↗
PubMed1998

Headache in systemic lupus erythematosus: a controlled study.

Intractable headaches, the so-called 'lupus headaches', have been long thought of as a common and characteristic manifestation of systemic lupus erythematosus (SLE). Seventy-eight patients with SLE, including 10 patients with definite central nervous system (CNS) involvement, and 89 healthy individuals matched for age, sex and socioeconomic status, were studied by a specific questionnaire addressing the characteristics and type of headache. Clinical features of SLE, neurological manifestations and treatment, disease severity and autoantibody profiles were correlated to the presence of headache. One year prevalence of headache was similar between patients (32%) and otherwise healthy individuals (30%). No significant differences regarding frequency, family history of headache and need for analgesic medication were observed. Headache refractory to analgesic treatment, but responsive to corticosteroid regimen, was recorded in only one patient. Clinical and serological features of SLE, including Raynaud's phenomenon and the presence of anticardiolipin antibodies, were not significantly different between headache sufferers and non-sufferers. In the majority of patients reporting headache, anxiety and/or depression co-existed. Episodic tension headache was the most frequent type, while migraine was traced in a quarter of headache sufferers. Neither the presence nor the clinical type of headache was related to, or predictive of, the development of seizures or psychosis. These results indicate that headache is not specifically related to SLE expression or severity, and suggest that accepting the presence even of a severe headache as a neurological manifestation of SLE in the absence of seizures or overt psychosis may result in overestimation of the disease status.

Adult↗
PubMed1998

Prevalence of Sjögren's-like syndrome in a cohort of HIV-1-positive patients: descriptive pathology and immunopathology.

The aims of the study were (a) to investigate the prevalence of Sjögren's-like syndrome (SLS) in an unselected population of HIV-1-positive patients and (b) to describe the pathology and immunopathology of the labial minor salivary gland biopsy. Seventy-seven HIV-1-positive patients were asked to answer the validated questionnaire of the European preliminary criteria for the classification of Sjögren's syndrome on oral and ocular sicca symptoms. Twenty-six patients gave one positive answer to both ocular and oral symptoms, and of these 14 (hepatitis C virus negative) consented to participate in the study (patients group). Ten age- and sex-matched HIV-1-positive patients with a negative questionnaire constituted the control group. Patients and controls had: (a) Schirmer's test and slit-lamp examination after Rose Bengal staining; (b) parotid gland scanning with technetium; (c) detection of autoantibodies in sera to Ro/SSA and La/SSB; (d) labial salivary gland biopsy (patients group only). The control group gave negative parotid gland scanning and only one gave a positive Rose Bengal staining test. In the patients group, parotid gland enlargement was manifested by three patients and only one gave positive Rose Bengal staining test. Six out of the 14 patients had biopsies identical with Sjögren's syndrome and five of these gave positive parotid gland scanning. In the biopsies of four other patients, mucoid degeneration of the stroma was found. Immunopathology revealed that the predominant cells were T cells with the CD8 phenotype. None of the patient and control sera had autoantibodies to Ro/SSA and La/SSB, whereas all patients had hypergammaglobulinaemia. The overall prevalence of possible SLS in a mixed population of HIV(+) patients (88.3% men and 11.7% women) was 7.79% which is >2.5 times higher than that observed in normal Greek adult females.

Adult↗
PubMed1998

Pregnancy outcome and anti-Ro/SSA in autoimmune diseases: a retrospective cohort study.

OBJECTIVE: In the present retrospective cohort study, the association of anti-Ro/SSA antibody with pregnancy loss and adverse pregnancy outcome in women with autoimmune diseases was investigated. MATERIALS AND METHODS: Obstetric histories of 154 anti-Ro/SSA-positive women with autoimmune diseases [78 systemic lupus erythematosus (SLE) and 76 non-SLE] were analysed and compared to a control group of 142 anti-Ro/SSA-negative women (71 SLE and 71 non-SLE) matched for disease diagnosis and age at the time of anti-Ro/SSA diagnosis. Obstetric history was also obtained and analysed from a group of healthy women, frequency matched to anti-Ro/SSA-positive women on age at study entry. RESULTS: The rate of pregnancy loss and adverse pregnancy outcome did not differ significantly between anti-Ro/SSA-positive women, anti-Ro/SSA-negative women and healthy controls. Anti-Ro/SSA-positive SLE women reported a significantly higher rate (18.0%) of therapeutic abortions compared to anti-Ro/SSA-negative women (5.6%, P=0.0244) and healthy controls (4.6%, P=0.0013). Anti-Ro/SSA non-SLE-positive women reported a significantly higher rate (23.7%) of recurrent pregnancy loss in comparison to anti-Ro/SSA-negative women (7.04%, P=0.0063) and healthy controls (6.4%, P=0.0004). CONCLUSIONS: Although anti-Ro/SSA antibody does not adversely affect pregnancy outcome in SLE patients, it appears to be associated with recurrent pregnancy loss in non-SLE patients.

Abortion, Spontaneous↗
PubMed1998

Clinical features and evolution of antinuclear antibody positive individuals in a rheumatology outpatient clinic.

OBJECTIVE: To identify individuals with antinuclear antibodies (ANA) not fulfilling criteria for systemic lupus erythematosus (SLE) or other connective tissue diseases (CTD); to describe their clinical and serological features, to identify factors indicating evolution to SLE. METHODS: A case-control study, based on retrospective evaluation of clinical files. The cases were ANA positive individuals (n = 50) examined in a medical outpatient setting, for symptoms compatible with SLE, but not fulfilling SLE classification criteria. Two patients with SLE were matched to each case in terms of age at initial symptom onset and sex. Thyroid autoimmunity was assessed by detecting antithyroid antibodies. Fisher's exact test and conditional logistic regression were used to evaluate the predictive ability of initial findings for SLE development. RESULTS: ANA positive individuals suspected of having a CTD present a wide variety of symptoms and findings, usually at the 4th to 5th decade of life. Antibodies to Sm and U1RNP were absent; anti-Ro(SSA) and anti-La(SSB) occurred in 6%, while anti-dsDNA occurred in less than 10% of the cases. Arthritis, butterfly and discoid rash, Raynaud's phenomenon, and anti-Ro/SSA antibodies are the initial findings indicating evolution to SLE. Hematological abnormalities such as leukopenia and thrombocytopenia as well as constitutional symptoms such as easy fatigue and arthralgias are not associated with evolution to SLE. Antithyroid antibodies were detected in 16% of the cases and 2.3% of controls. CONCLUSION: ANA may connote a form of systemic autoimmunity that is expressed as a wide variety of complaints, even in the absence of a definite diagnosis of CTD. Arthritis, rash, Raynaud's phenomenon, and anti-Ro/SSA antibodies indicate evolution to SLE. Autoimmune thyroid disease occurs in ANA positive individuals not fulfilling SLE classification criteria rather than in patients with SLE.

Adult↗
PubMed1998

Hypofunction of the stress axis in Sjögren's syndrome.

OBJECTIVE: To examine the functional integrity of the hypothalamic-pituitary-adrenal (HPA) and thyroid axes in Sjögren's syndrome (SS) via the assessment of basal and stimulated adrenocorticotropin (ACTH), cortisol, thyroid stimulating hormone (TSH), and prolactin levels. METHODS: Pituitary function of the HPA axis was assessed by determining the basal plasma levels of ACTH in the late afternoon, as well as the ACTH released to ovine corticotropin releasing hormone (oCRH) stimulation; adrenal function was assessed by measuring plasma cortisol levels in the late afternoon at baseline and after release of the endogenous ACTH during oCRH stimulation. Basal and thyrotropin releasing hormone (TRH) stimulated levels of TSH and prolactin were also assessed. Healthy volunteers were used as controls. RESULTS: Patients with SS, compared to controls, were characterized by significantly lower ACTH levels (pg/ml), (5.1 +/- 0.5 vs 11.4 +/- 1.5, respectively; p < 0.05) and cortisol levels (microg/ml), (2.4 +/- 0.6 vs 5.9 +/- 1.2, respectively; p < 0.05). Furthermore, a blunted pituitary and adrenal response to oCRH compared to controls was observed: peak plasma ACTH and cortisol levels for patients with SS were 46.2 +/- 5.4 pg/ml and 15.7 +/- 1.6 microg/ml, respectively, and for controls 61.5 +/- 3.8 and 19.6 +/- 0.7, respectively (p < 0.05). Basal TSH levels were significantly elevated in patients (1.3 +/- 0.3 microIU/ml vs 0.9 +/- 0.05 microIU/ml; p < 0.05). CONCLUSION: The above findings indicate hypoactivity of the HPA axis in patients with SS. Further studies are needed to definitively identify the locus of the defects and assess the significance of the pattern of the perturbations to the pathogenesis and expression of SS.

Adrenocorticotropic Hormone↗
PubMed1997

Autoantibodies to human recombinant erythropoietin in patients with systemic lupus erythematosus: correlation with anemia.

OBJECTIVE: To investigate the existence of circulating autoantibodies to erythropoietin (EPO) in sera from patients with systemic lupus erythematosus (SLE), and to correlate their presence with anemia and clinical activity. METHODS: Ninety-two consecutive patients with SLE, 80 patients with rheumatoid arthritis, and 42 normal individuals were studied. The patients with SLE were categorized into 3 groups according to hemoglobin (Hgb) level: group A (45 patients with Hgb > 12 gm/dl), group B (26 patients with Hgb 10.1-12 gm/dl), and group C (21 patients with Hgb < or = 10 gm/dl). In all patients with SLE, the disease activity was evaluated using the European Consensus Lupus Activity Measurement scale. Antibodies to EPO were detected using an enzyme-linked immunosorbent assay and purified recombinant human EPO as antigen. The specificity of the method was evaluated with homologous and cross-reactive inhibition assays. RESULTS: Antibodies to EPO were found in 15.2% of the SLE patient sera. The distribution of these antibodies among the 3 groups of SLE patients was as follows: 8.8% (4 of 45) from group A, 15.4% (4 of 26) from group B, and 28.6% (6 of 21) from group C. The prevalence of antibodies to EPO in patients with severe anemia (group C) was statistically significantly higher compared with patients without anemia (chi(2) = 4.31, P < 0.05). Patients with antibodies to EPO had higher disease activity scores (P < 0.005) and lower levels of the C4 component of complement (P < 0.05) compared with patients without antibodies to EPO. CONCLUSION: In this study, the presence of antibodies to EPO in the sera of SLE patients is demonstrated for the first time. The presence of these antibodies is associated with severe anemia and active disease.

Adolescent↗
PubMed1997

Fine specificity of autoantibodies to La/SSB: epitope mapping, and characterization.

The B cell epitope mapping of La/SSB was performed using 20mer synthetic peptides overlapping by eight amino acids covering the whole sequence of the protein. IgG, purified from sera of five patients with systemic lupus erythematosus (SLE) and four sera from patients with primary Sjögren's syndrome (pSS) were tested against the overlapping synthetic peptides. Peptides highly reactive with purified IgG were those spanning the regions 145-164, 289-308, 301-320 and 349-368 of the La protein. Determination of the minimum required length of the antigenic determinants disclosed the following epitopes: 147HKAFKGSI154, 291NGNLQLRNKEVT302, 301VTWEVLEGEVEKEALKKI318 and 349GSGKGKVQFQGKKTKF364. Predicted features and molecular similarities of the defined epitopes were investigated using protein databases. The La epitope 147HKAFKGSI154 presented 83.3% similarity with the 139HKGFKGVD146 region of human myelin basic protein (MBP) and 72% similarity with the fragment YKNFKGTI of human DNA topoisomerase II. Peptides corresponding to these sequences cross-reacted with anti-La/SSB antibodies. Sixty-three sera with anti-La/SSB antibodies from patients with pSS or SLE, 35 sera without anti-La/SSB antibodies from patients with SS or SLE and 41 sera from age/sex-matched healthy blood donors were tested against biotinylated synthetic epitope analogues in order to determine their sensitivity and specificity for the detection of anti-La/SSB antibodies. Anti-La/SSB were detected with various frequencies ranging from 20% to epitope 147HKAFKGSI154 to 100% to epitope 349GSGKGKVQGKKTKF364. The overall sensitivity and specificity using all assays with the synthetic peptides were found to be 93.6% and 85.6%, respectively. In conclusion, antibodies to La/SSB constitute a heterogeneous population, directed against different linear B cell epitopes of the molecule. The epitope 147HKAFKGSI154 presents molecular similarity with fragments of two other autoantigens, i.e. human MBP and DNA topoisomerase II. Finally, synthetic epitope analogues exhibit high sensitivity and specificity for the detection of anti-La/SSB antibodies.

Adult↗