Contribution of MTHFR gene variants in lupus related subclinical atherosclerosis.

OBJECTIVE: Elevated concentrations of homocysteine have been previously identified as an independent risk factor for subclinical atherosclerosis in patients with systemic lupus erythematosus (SLE). Given that heightened homocysteine levels are known to be strongly influenced by genetic factors, in the current study we investigated the contribution of high homocysteine levels as well as of functional polymorphisms of the gene encoding for the enzyme 5, 10- methylenetetrahydrofolate reductase (MTHFR) to atherosclerotic disease characterizing SLE patients. METHODS: Peripheral DNA samples from 150 SLE patients, 214 rheumatoid arthritis (RA) patients and 561 age/sex matched apparently healthy volunteers (HC) were genotyped by PCR-based assays for the detection of the MTHFR gene polymorphisms (c. 677C > T and c. 1298A > C). All SLE patients and 30 age sex matched RA patients underwent assessment for subclinical atherosclerosis [ultrasound measurement of intima-media thickness scores (IMT) and detection of carotid and/or femoral (C/F) plaque] and complete clinical and laboratory evaluation including serum homocysteine levels. Data were analyzed using univariate and multivariate models (SPSS 21.0). RESULTS: Hyperhomocysteinemia was detected in 26.0% of SLE patients compared to 6.7% of age/sex matched RA controls (p = 0.02). Higher serum B12 levels and decreased frequency of the MTHFR 677TT variant in RA patients could potentially account for the observed differences between the groups. In SLE patients, both hyperhomocysteinemia and MTHFR 677TT genotype were identified as independent contributors for plaque formation, following adjustment for traditional cardiovascular risk factors and disease related features, including age, sex, BMI, cholesterol and triglyceride levels, presence of arterial hypertension, smoking (pack/years), disease duration and total steroid dose [OR 95% (CI): 5.8 (1.0-35.8) and 5.2 (1.1-24.0), respectively]. MTHFR 677TT genotype, but not hyperhomocysteinemia was also found to confer increased risk for arterial wall thickening, after the above confounders were taken into account [OR (95%) CI: 4.9 (1.2-20.6)]. CONCLUSIONS: Hyperhomocysteinemia and MTHFR 677TT genetic variant emerged as independent risk factors for subclinical atherosclerosis in SLE patients, implying genetic influences as potential contributors to the increased burden of atherosclerotic disease characterizing SLE.

Prevalence and spectrum of symptomatic pulmonary involvement in primary Sjögren's syndrome.

OBJECTIVES: The present cross-sectional study aimed to estimate the prevalence of chronic respiratory symptoms in primary Sjögren's syndrome (pSS) and define the clinical, functional and imaging characteristics of symptomatic pulmonary disease in pSS. METHODS: Four hundred and fourteen consecutive pSS patients were interviewed for the presence of chronic respiratory complaints (cough and/or dyspnea). Symptomatic pSS patients without respiratory or other comorbidities underwent further investigation with clinical evaluation and assessment with pulmonary functional testing (PFTs) and chest high resolution CT (hrCT) on inspiratory and expiratory phase. Comparison of clinical and laboratory features between symptomatic and asymptomatic pSS patients was also performed. RESULTS: Prevalence of chronic respiratory symptoms in pSS was estimated at 21.5% (89/414). Symptoms were attributed to underlying comorbidities in approximately one third of cases (30/89). Thirty nine of the remaining 59 patients were finally assessed with PFTs and hrCT. Small airway disease was diagnosed in 20 individuals with an obstructive pattern in PFTs and/or compatible radiological signs. Seven patients were diagnosed with interstitial lung disease, while in the remaining 12 pSS patients, with normal PFTs and hrCT, symptoms were attributed to xerotrachea. Raynaud's phenomenon occurred more frequently in symptomatic than asymptomatic patients (p=0.024). CONCLUSIONS: Approximately one fifth of a large cohort of pSS patients presented chronic respiratory symptoms. Small airway disease was the most commonly recognized pulmonary disorder among symptomatic pSS patients, followed by xerotrachea and interstitial lung disease.

Analysis of the cell populations composing the mononuclear cell infiltrates in the labial minor salivary glands from patients with rheumatoid arthritis and sicca syndrome.

OBJECTIVES: Sicca symptoms occur in around 30% of rheumatoid arthritis (RA) patients. Herein, we examined the characteristics of RA patients bearing sicca symptomatology (RA-sicca) with a special focus on the immunohistopathological features of their labial minor salivary gland (LMSG) biopsies. METHODS: Our cohort included 100 consecutive RA patients which were interrogated using a sicca symptoms questionnaire. Positive responders were evaluated for ocular and oral dryness and underwent an LMSG biopsy. All samples were immunohistochemically evaluated for the presence and distribution of specific leukocyte subsets using appropriate markers and for the expression of certain immunoregulatory molecules by salivary gland epithelial cells. Positively stained and total mononuclear cells (MNC) were counted in the entire section. Counts were expressed as cell frequency (percentage of cell type number/total infiltrating MNC number). RESULTS: In the majority (86.1%) of the 44 RA-sicca cases, periductal infiltrates were observed in LMSG biopsies. The frequencies of infiltrating cell subtypes and their correlation with lesion severity were different from that previously described in primary Sjögren's syndrome (pSS). Moreover, DCs and ΜΦs frequencies were increased in RA-sicca patients who had a biopsy focus score <1 and absence of anti-Ro/anti-La autoantibodies, in contrast to what was observed for B cells. In about half of the biopsies, salivary gland epithelial cells expressed CD80/B7.1 molecules, most commonly in patients with a positive biopsy or anti-Ro/anti-La autoantibodies. CONCLUSION: LMSG infiltrates composition in RA-sicca patients is distinct from that described in pSS. These differences, further attest to diverse pathophysiologic processes operating in these two entities.

MTHFR gene variants and non-MALT lymphoma development in primary Sjogren's syndrome.

Primary Sjogren's syndrome (pSS) confers increased risk for non-Hodgkin lymphoma (NHL) development. Two common polymorphisms, the c. 677C > T and c. 1298A > C, of the methylene-tetrahydrofolate reductase (MTHFR) gene, an enzyme essential in DNA synthesis and methylation, have been associated with susceptibility to NHL. Herein, we tested the hypothesis that MTHFR variants contribute to pSS-related lymphomagenesis. 356 pSS patients, of whom 75 had MALT and 19 non-MALT NHL and 600 healthy controls were genotyped for the detection of MTHFR polymorphisms. DNA methylation levels were assessed by pyrosequencing of the LINE-1 retroelement promoter in DNA from 55 salivary gland tissues from pSS patients. DNA double-strand breaks were determined in peripheral blood mononuclear cells from 13 pSS patients, using comet assay. Αnalysis according to lymphoma subtype revealed increased frequency of c. 677C > T TT genotype and T allele, as well as reduced prevalence of the c. 1298A > C C allele in the pSS non-MALT group compared to controls and patients without NHL. MTHFR c. 677C > T TT genotype was associated with reduced DNA methylation levels, while MTHFR c. 1298A > C AC genotype with reduced DNA double-strand breaks levels. MTHFR variants may be involved in SS non-MALT NHL development, through contribution to defective DNA methylation and genomic instability.

Predicting the risk for lymphoma development in Sjogren syndrome: An easy tool for clinical use.

The heightened risk of non-Hodgkin lymphoma (NHL) development in primary Sjogren syndrome (SS) is well established. Several adverse clinical and laboratory predictors have been described. In the current work, we aimed to formulate a predictive score for NHL development, based on clinical, serological, and histopathological findings at the time of SS diagnosis. In the present case-control study of 381 primary SS patients and 92 primary SS patients with concomitant NHL, clinical, serological, and histopathological variables at the time of SS diagnosis were retrospectively recorded. For the identification of predictors for NHL development univariate and multivariate models were constructed. Salivary gland enlargement (SGE), lymphadenopathy, Raynaud phenomenon, anti-Ro/SSA or/and anti-La/SSB autoantibodies, rheumatoid factor (RF) positivity, monoclonal gammopathy, and C4 hypocomplementemia were shown to be independent predictors for NHL development. On the basis of the number of independent risk factors identified, a predictive risk score for NHL development was formulated. Thus, patients presenting with ≤2 risk factors had a 3.8% probability of NHL development, those with 3 to 6 risk factors 39.9% (OR (95%CI): 16.6 [6.5-42.5], P < 0.05), while in the presence of all 7 risk factors the corresponding probability reached 100% (OR [95%CI]: 210.0 [10.0-4412.9], P < 0.0001). In conclusion, an easy to use diagnostic scoring tool for NHL development in the context of SS is presented. This model is highly significant for the design of early therapeutic interventions in high risk SS patients for NHL development.