Evidence of epigenetic alterations in thrombosis and coagulation: A systematic review.

Thrombosis in the context of Cardiovascular disease (CVD) affects mainly the blood vessels supplying the heart, brain and peripheries and it is the leading cause of death worldwide. The pathophysiological thrombotic mechanisms are largely unknown. Heritability contributes to a 30% of the incidence of CVD. The remaining variation can be explained by life style factors such as smoking, dietary and exercise habits, environmental exposure to toxins, and drug usage and other comorbidities. Epigenetic variation can be acquired or inherited and constitutes an interaction between genes and the environment. Epigenetics have been implicated in atherosclerosis, ischemia/reperfusion damage and the cardiovascular response to hypoxia. Epigenetic regulators of gene expression are mainly the methylation of CpG islands, histone post translational modifications (PTMs) and microRNAs (miRNAs). These epigenetic regulators control gene expression either through activation or silencing. Epigenetic control is mostly dynamic and can potentially be manipulated to prevent or reverse the uncontrolled expression of genes, a trait that renders them putative therapeutic targets. In the current review, we systematically studied and present available data on epigenetic alterations implicated in thrombosis derived from human studies. Evidence of epigenetic alterations is observed in several thrombotic diseases such as Coronary Artery Disease and Cerebrovascular Disease, Preeclampsia and Antiphospholipid Syndrome. Differential CpG methylation and specific histone PTMs that control transcription of prothrombotic and proinflammatory genes have also been associated with predisposing factors of thrombosis and CVD, such us smoking, air pollution, hypertriglyceridemia, occupational exposure to particulate matter and comorbidities including cancer, Chronic Obstructive Pulmonary Disease and Chronic Kidney Disease. These clinical observations are further supported by in vitro experiments and indicate that epigenetic regulation affects the pathophysiology of thrombotic disorders with potential diagnostic or therapeutic utility.

Disease activity and damage accrual during the early disease course in a multinational inception cohort of patients with systemic lupus erythematosus.

An inception cohort of patients with systemic lupus erythematosus from 14 European centres was followed for up to 5 years in order to describe the current early disease course. At inclusion patients (n = 200, 89% female, mean age 35 years, 97% Caucasian, mean SLEDAI 12.2) fulfilled a mean of 6.5 ACR classification criteria. The most prevalent criteria were antinuclear Ab presence (97%) followed by anti-dsDNA Ab (74%), arthritis (69%), leukocytopenia (54%) and malar rash (53%), antiphospholipid Ab (48%) and anti-synovial membrane Ab (21.6%). Clinical signs of lupus nephritis (LN) were present in 39% with biopsy-confirmed LN seen in 25%. Frequent additional findings were hypocomplementaemia (54%), anti-SSA Ab (49%), alopecia (26%) and Raynaud's phenomenon (31%). There were few regional differences in disease presentation and management. One and 5-year survival rates were 99% and 97% respectively. During the mean follow-up of 4.1 years 25% entered a state of early disease quiescence by global physician assessment, but the overall risk of subsequent flare was 60%. Maximum SLEDAI scores decreased over time, but 45% of patients accrued damage (SDI >or=1) for which baseline presence of proteinuria and persistent disease activity were independent predictors. The results indicate minor differences in SLE presentation and treatment within various regions of Europe and a high diagnostic reliance on anti-dsDNA Ab. Despite early reductions in disease activity and improved mortality, the risk for disease flare and damage development is, however, still substantial, especially in patients not entering an early remission.

Estrogen receptor alpha gene polymorphism and systemic lupus erythematosus: a possible risk?

Estrogens and their receptors may play a role in the pathogenesis of systemic lupus erythematosus. Genetic alterations in the exon 8-coding region of the estrogen receptor alpha alter the intracellular signalling of estrogens, leading in enhanced or diminished activity. We investigated whether genetic alterations in exon 8 of ERalpha gene are associated with the occurrence and clinical features of lupus disease. The coding region of ERalpha exon 8 was subjected to mutation analysis using the polymerase chain reaction, denaturing gradient gel electrophoresis and sequence analysis, using DNA isolated from whole blood of 36 female patients and 38 healthy females. Clinical and laboratory parameters were available from the patients' files. We identified the codon 594 polymorphism either in homozygous for the wild type gene (ACG/ACG) or heterozygous (ACG/ACA), both in patients and healthy females. Statistical analysis of the genotype and allele distribution revealed that there was a significant difference (chi2 test, P = 0.02 and P = 0.04, respectively) between patients and healthy women. Odds ratio estimate revealed that carriers of ACG/ACA genotype have three-fold higher risk of developing lupus disease (OR = 3.129, 95% CI 1.181-8.292). Moreover, in patients the heterozygous genotype was associated with rash, mouth ulcers and serositis (Fisher's exact test, P = 0.055, P = 0.083, P = 0.065, respectively). The heterozygous patients were associated significantly with an early age at disease onset (ANOVA test, P < 0.05). We conclude that estrogen receptor alpha codon 594 genotype may influence the development of systemic lupus erythematosus at a younger age, as well as a certain disease clinical pattern.

Presence of systemic autoimmune disorders in patients with autoimmune thyroid diseases.

OBJECTIVE: To evaluate the prevalence of antinuclear antibodies (ANA) in patients with autoimmune thyroid diseases (ATD) and the presence of systemic autoimmune disorders among ANA positive patients with ATD. METHODS: 168 consecutive patients with ATD with positive antithyroid antibodies and 75 healthy subjects were tested for the presence of ANA. ANA positive patients were further evaluated by complete history, physical examination, blood and urine tests, and immunological studies. Patients with subjective xerophthalmia and xerostomia were examined by objective tests. RESULTS: 58/168 (35%) patients with ATD were ANA positive compared with 7/75 (9%) healthy controls (p = 0.001). Of 58 ANA positive patients, 6 (10%) had anti-Ro antibodies, 1 had anti-Ro and anti-La antibodies, 7 (12%) had anti-dsDNA antibodies, and 7 (12%) had medium levels of IgG and/or IgM anticardiolipin antibodies (aCL). No healthy subjects had positive anti-dsDNA, antibodies against the extractable nuclear antigens, or aCL. 5/58 (9%) patients fulfilled the criteria for Sjögren's syndrome (SS). Two patients had features related to systemic lupus erythematosus. No healthy subjects had clinical or laboratory characteristics of systemic autoimmune disorders. CONCLUSION: ANA are detected in 1/3 of patients with ATD. Anti-dsDNA, anti-Ro, and aCL can also be found in ANA positive patients with ATD. SS occurs in about 1/10 of ANA positive patients with ATD.

A diepitopic sequential oligopeptide carrier (SOCn) as mimic of the sm autoantigen: synthesis, conformation and biological assays.

Anti-Sm (Sm: U1-U6 RNA-protein complex) antibodies are usually considered highly specific for systemic lupus erythematosus (SLE), while anti-U1RNP (U1RNP: U1RNA-protein complex) are thought of as diagnostic criteria for the mixed connective tissue disease (MCTD). However, both antibody specificities coexist in SLE and MCTD, in varying percentages. Although the anti-Sm/anti-U1RNP immunological cross-reactivity has been initially attributed to a common motif, PPXY(Z)PP (where X, Y, Z are various amino acids), found in the Sm, U1-A and U1-C autoantigens, it appears that the conformational features of the Sm epitopes also play an important role in the immunoreactivity. The PPGMRPP and PPGIRGP main epitopes of the Sm antigen were coupled in duplicate to the tetrameric Ac-(Lys-Aib-Gly)4-OH, SOC4, carrier to form the [(PPGMRPP)2, (PPGIRGP)2]-SOC4 construct as a mimic of the native Sm. It was found that: (i) the 3(10) helical structure of SOC4 allows the epitopes to adopt an exposed orientation, similar to their free forms, that facilitates their recognition from the anti-Sm antibodies, and (ii) the U1-RNP cross-reactivity is minimized.

Molecular analysis of estrogen receptor alpha and beta in lupus patients.

BACKGROUND: In female patients with systemic lupus erythematosus (SLE), we identified estrogen receptor ERa, ERb and ERa variant transcripts in peripheral blood mononuclear cells (PBMC). Exon 1 and 2 of ERa gene was subjected to mutation analysis to assess whether possible nucleotide alterations are linked to the disease. METHODS: The whole coding sequence of ERa was analysed by reverse transcription polymerase chain reaction (RT-PCR) and cDNA sequencing in PBMC prepared from 19 SLE patients and 12 healthy females. ERa exon 1 and exon 2 were subjected to mutation analysis using DNA isolated from whole blood of 21 SLE patients and 29 healthy females. The aminoterminal coding sequence of ERb was also analysed by RT-PCR. RESULTS: Wild type ERa and ERa splicing variants with deletions in exons 2, 5 and 7 were detected both in healthy individuals and in SLE patients, with no qualitative difference in their expression among the two populations. In ERa exon 1, the polymorphisms identified codon 10 and codon 87, both in patients and in healthy individuals who were not associated with the disease. No other mutations were present in ERa exon 1 or ERa exon 2 in all subjects studied. ERb was expressed in both populations. CONCLUSION: PBMC of SLE patients express wild type ERa, ERb and the same ERa variants as do healthy individuals. Genetic alterations in exon 1 and exon 2 of the ERa gene are not linked with SLE disease.

Incomplete lupus erythematosus: results of a multicentre study under the supervision of the EULAR Standing Committee on International Clinical Studies Including Therapeutic Trials (ESCISIT).

OBJECTIVE: Patients characterized with antinuclear antibodies (ANA) and disease symptoms related to one organ system can be described as having incomplete systemic lupus erythematosus (SLE). The aim of this multicentre study was to describe the outcome of these so-called incomplete SLE patients. Two aspects of the outcome were studied: (i) the disease course, defined by the presence or absence of clinical symptoms; and (ii) the number of patients that eventually developed full SLE. METHODS: Outcome parameters were the ACR criteria, the SLE disease Activity Index (SLEDAI), the European Consensus Lupus Activity Measure (ECLAM) and the requirement for treatment. In 10 European rheumatology centres, patients who had been evaluated in the last 3 months of 1994 and had been diagnosed as having incomplete SLE on clinical grounds for at least 1 yr were included in the study. All 122 patients who were included in the study were evaluated annually during 3 yr of follow-up. RESULTS: Our results are confined to a patient cohort defined by disease duration of at least 1 yr, being under clinical care at the different centres in Europe. These patients showed disease activity that was related mostly to symptoms of the skin and the musculoskeletal system, and leucocytopenia. During the follow-up, low doses of prednisolone were still being prescribed in 43% of the patients. On recruitment to the study, 22 of the 122 incomplete SLE patients already fulfilled the ACR criteria for the diagnosis of SLE. In the 3 yr of follow-up only three patients developed SLE. CONCLUSIONS: A high proportion of patients in our cohort defined on clinical grounds as having incomplete SLE eventually showed disease activity defined by the SLEDAI as well as ECLAM. However, only three cases developed to SLE during the follow-up. This suggests that incomplete SLE forms a subgroup of SLE that has a good prognosis.

The position of the LysN epsilon H2-grafted antigens along the sequential oligopeptide carrier, Ac-(Aib-Lys-Aib-Gly)n (SOCn-II), influences the antibody recognition: application to the Sm main autoimmune epitope.

A sequential oligopeptide carrier of antigenic peptides is presented, incorporating two Aib residues in each repetitive moiety: Ac-(Aib-Lys-Aib-Gly)(n) (SOC(n) -II; n = 2-4). The conformational study, by (1)H-nmr, CD, and Fourier transform ir spectroscopy, indicated that the SOC(n) -II carrier displays a pronounced 3(10)-helix, compared to the Ac-(Lys-Aib-Gly)(n) (SOC(n) -I) carrier of the same approximately backbone length, previously reported. One of the dominant autoimmune epitopes of the Sm and U1RNP cellular components, the PPGMRPP sequence, was coupled to the Lys-N(epsilon)H(2) groups of the SOC(n) -II carrier and used as antigenic substrate for detecting anti-Sm/U1RNP autoantibodies in ELISA assays. Anti-Sm antibodies are highly specific for systemic lupus erythematosus, while anti-U1RNP are specific for mixed connective tissue disease. The anti-(PPGMRPP)(5)-SOC(n) -II ELISA was compared with the anti-(PPGMRPP)(n) -SOC(n) -I ELISA, provided that both antigenic substrates possess the same amount of the epitope replicates. The significance of the lysine positions along the oligopeptide backbone of the carrier for a favorable antibody recognition of the anchored antigens is also examined.

No evidence of epitope spreading after immunization with the major Sm epitope P-P-G-M-R-P-P anchored to sequential oligopeptide carriers (SOCs).

The sequence Pro-Pro-Gly-Meth-Arg-Pro-Pro (PPGMRPP) is the major B-cell epitope of the Sm autoantigen. The aim of the present study was to evaluate the immune response against the native forms of Sm and U1RNP and immune mediated tissue injury after immunization with the sequence PPGMRPP anchored in five copies to a new type helicoid sequential oligopeptide carrier (SOC) formed by the repetitive Lys-Aib-Gly moiety, [(PPGMRPP)(5)SOC(5)]. Rabbits (n=3) were immunized with 0.5 mg of (PPGMRPP)(5)SOC(5)in complete Freud's adjuvant and boosted at days 26, 53, 99; control rabbits were immunized with the PPGMRPP alone (n=3), phosphate buffered saline (PBS) (n=1), SOC(5)alone (n=1), a peptide at aminoacid (aa) position 158-177 of myelin basic protein (MBP aa 158-147) (n=1) and three La/SSB autoantigen B-cell epitopes (n=3). Antibodies to (PPGMRPP)(5)SOC(5)were determined by enzyme linked immunosorbent assay (ELISA); precipitating anti-Sm and anti-U1RNP antibodies were detected by RNA precipitation and western blot on HeLa total cellular and nuclear extract and 12s sucrose gradient fraction of rat liver extracts. High titres of anti-(PPGMRPP)(5)SOC(5)antibodies not recognizing the native forms of Sm or U1RNP antigens were detected in the (PPGMRPP)(5)SOC(5)immunized but not in the control animals. The sera of two (PPGMRPP)(5)SOC(5)immunized but not of the control rabbits recognized a 67 kDa protein in HeLa nuclear extract, distinct from the 70 kDa U1RNP antigen. Diffuse and segmental increase of mesangeal matrix and cells, crescent formation, segmental glomerular necrosis, rarely massive subendothelial deposits occluding the lumen and C3 complement component in the mesangeal area were seen in the kidneys of one (PPGMRPP)(5)SOC(5)immunized, but not of the remaining animals. In conclusion, the immune response induced by (PPGMRPP)(5)SOC(5)was specific for the immunizing epitope but not for the native forms of Sm and U1RNP antigens, but it was associated with immune mediated kidney injury.

Peptide carriers: A helicoid-type sequential oligopeptide carrier (SOC(n)) for multiple anchoring of antigenic/immunogenic peptides.

A new peptide carrier with three-dimensional predetermined structural motif has been constructed by the repetitive Lys-Aib-Gly moiety. The sequential oligopeptide carrier (SOC(n)), (Lys-Aib-Gly)(n), adopts a distorted 3(10)-helical conformation and the Lys-N(epsilon)H(2) anchoring groups exhibit defined spatial orientations. Conformational analysis of the SOC(n) conjugates showed that the coupled peptides retain their initial "active" structure, while prevalence of one conformer was also observed. It is concluded that the beneficial structural elements of SOC(n) induce a favorable arrangement of the conjugated peptides, so that potent antigens and immunogens are generated.

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.

Therapy of Sjögren's syndrome. New aspects and future directions.

Therapy of Sjögren's syndrome remains empirical and symptomatic. The main goals are to treat the disease related features, especially sicca manifestations, since the immunosuppressive therapy has not given promising results. For the treatment of keratoconjunctivitis sicca: local stimulators of tear secretion, protective bicarbonate buffered solutions, replacement therapy or supportive operative procedures should be tried. For oral manifestations: stimulators of salivary secretion such as pilocarpine, or agents changing the consistency of saliva such as bromhexine orally should be tried. Saliva substitutes have a transient effect. Frequent ingestion of sugar free liquids may help. Oral hygiene is important to avoid oral candidiasis and dental caries. Treatment of parotid gland swelling is not necessary. Pulmonary manifestations include pulmonary infiltrates in perialveolar areas, nodular or cavitary lesions which may represent lymphoma. Hilar adenopathy, solid or cavitary lesions should be biopsied. In case of vasculitis prednisolone 1 mg/kg/day with progressive tapering should be tried. Renal involvement is manifested mainly as interstitial disease. Administration of NaHCO3 or sodium citrate is important to prevent acidosis and nephrocalcinosis. Vasculitis, when it is of the leukoclasic form, does not need therapy; when it is manifested with severe major organ involvement corticosteroids and/or cytotoxic therapy should be tried. Lymphoma is treated as in the patients without Sjögren's in close collaboration with the oncology department.

Antibodies to nRNP, Sm, Ro(SSA) and La(SSB) detected by ELISA: their specificity and inter-relations in connective tissue disease sera.

The profile of autoantibodies to four soluble cellular ribonucleoproteins nRNP, Sm Ro(SSA) and La(SSB) was determined using ELISA with immuno-affinity-purified antigens in a connective tissue disease population. Compared with immunodiffusion, results using ELISA showed greater sensitivity but lower specificity and low titres of antibodies were frequently found in the sera of patients with connective tissue diseases other than systemic lupus erythematosus. This was true even for antibodies to Sm which have been considered highly specific for SLE. Antibodies to these antigens were predominantly of the IgG class and were capable of fixing complement irrespective of the clinical context. As previously demonstrated by immunodiffusion strong associations between anti-nRNP and anti-Sm and between anti-Ro(SSA) and anti-La(SSB) were detected by ELISA, while antibodies to nRNP and to Ro(SSA) identify distinctive serological groups. The observation that certain antibodies are closely linked suggests a relationship between the immune responses to particular antigens, and this might be explained by biological links between the antigens.