Differential expression pattern of microRNAs in CD4+ and CD19+ cells from asymptomatic patients with systemic lupus erythematosus.

OBJECTIVE: The aim of this study was to investigate the pattern of microRNA (miRNA) expression in CD19+ and CD4+ cells from asymptomatic patients with systemic lupus erythematosus (SLE). METHODS: A screening of the expression of 377 miRNAs was performed in human CD4+ and CD19+ cells isolated from the peripheral blood by using a TaqMan Human MicroRNA Array. Validation of differential expression pattern of those was performed using TaqMan assays in these cell populations obtained from a larger cohort of patients and controls. RESULTS: According to the screening assays, three miRNAs were differentially expressed (p value <0.1) in cell populations from both patients and controls: hsa-miR-143, hsa-miR-224 and hsa-miR-576-5p for CD4+ cells, and hsa-miR-10a, hsa-miR-31 and hsa-miR-345 for CD19+ cells. After validation, significant differences (p value <0.05) were confirmed only for hsa-miR-143 and hsa-miR-224 in CD4+ cells and for hsa-miR-10a and hsa-miR-345 in CD19+ cells. In all cases, the miRNAs were over expressed in SLE patients compared with healthy donors. CONCLUSIONS: Our results support a different pattern of miRNA expression in SLE patients.

The autoimmune disease-associated IL2RA locus is involved in the clinical manifestations of systemic sclerosis.

Regulatory T cells (T(regs)) are crucial in the maintenance of the immune tolerance and seem to have an important role in systemic sclerosis (SSc). The interleukin 2 receptor α (IL2RA) is an important T(reg) marker, and polymorphisms of IL2RA gene are associated with a number of autoimmune diseases. Therefore, we aimed to investigate for the first time the association of the IL2RA locus in SSc. For this purpose, a total of 3023 SSc patients and 2735 matched healthy controls, from six European Caucasian cohorts, were genotyped for the IL2RA gene variants rs11594656, rs2104286 and rs12722495 using the TaqMan allelic discrimination technology. The overall meta-analysis reached statistical significance when the three polymorphisms were tested for association with SSc, the limited subtype (lcSSc) and anti-centromere auto-antibodies (ACAs). However, no significant P-values were obtained when the ACA-positive patients were removed from the SSc and lcSSc groups, suggesting that these associations rely on ACA positivity. The strongest association signal with ACA production was detected for rs2104286 (P(FDR)=2.07 × 10(-4), odds ratio=1.30 (1.14-1.47)). The associations of rs11594656 and rs12722495 were lost after conditioning to rs2104286, and allelic combination tests did not evidence a combined effect, indicating that rs2104286 best described the association between IL2RA and ACA presence in SSc.

No evidence of association between functional polymorphisms located within IL6R and IL6ST genes and systemic sclerosis.

Systemic sclerosis (SSc) is a complex autoimmune disease which genetic component has not been yet completely understood. IL6 encodes a cytokine with a crucial role in the development of autoimmunity and fibrosis and its actions mainly are controlled by IL-6 receptor (IL-6R). We aimed to investigate whether the functional genetic variants rs8192284 and rs2228044 previously associated with several autoimmune diseases, located within the IL-6 receptor (IL-6R) subunits IL6R and IL6ST genes, respectively, are involved in the susceptibility to SSc and/or its major clinical subphenotypes. A Spanish cohort including 1013 SSc patients and 1375 controls was genotyped using the TaqMan® allelic discrimination technology. SSc patients were subdivided according to the major clinical forms, autoantibody status and presence of fibrotic lung affection. Our data showed no influence of the selected variants in global SSc susceptibility (rs8192284: P=0.67, odds ratios (OR)=0.98; rs2228044: P=0.99, OR=1.00). Similarly, the clinical/autoantibody subphenotype analyses did not yielded significant results. Our data suggest that the analyzed polymorphisms may not play a significant role in the SSc susceptibility.

Analysis of the influence of PTPN22 gene polymorphisms in systemic sclerosis.

OBJECTIVE: Two functional single nucleotide polymorphisms (SNP) in the PTPN22 gene (rs24746601 and rs33996649) have been associated with autoimmunity. The aim of this study was to investigate the role of the R263Q SNP for the first time and to re-evaluate the role of the R620W SNP in the genetic predisposition to systemic sclerosis (SSc) susceptibility and clinical phenotypes. METHODS: 3422 SSc patients (2020 with limited cutaneous SSc and 1208 with diffuse cutaneous SSc) and 3638 healthy controls of Caucasian ancestry from an initial case--control set of Spain and seven additional independent replication cohorts were included in our study. Both rs33996649 and rs2476601 PTPN22 polymorphisms were genotyped by TaqMan allelic discrimination assay. A meta-analysis was performed to test the overall effect of these PTPN22 polymorphisms in SSc. RESULTS: The meta-analysis revealed evidence of association of the rs2476601 T allele with SSc susceptibility (p(FDRcorrected)=0.03 pooled, OR 1.15, 95% CI 1.03 to 1.28). In addition, the rs2476601 T allele was significantly associated with anticentromere-positive status (p(FDRcorrected)=0.02 pooled, OR 1.22, 95% CI 1.05 to 1.42). Although the rs33996649 A allele was significantly associated with SSc in the Spanish population (p(FDRcorrected)=0.04, OR 0.58, 95% CI 0.36 to 0.92), this association was not confirmed in the meta-analysis (p=0.36 pooled, OR 0.89, 95% CI 0.72 to 1.1). CONCLUSION: The study suggests that the PTPN22 R620W polymorphism influences SSc genetic susceptibility but the novel R263Q genetic variant does not. These data strengthen evidence that the R620W mutation is a common risk factor in autoimmune diseases.

Failure of intravenous immunoglobulin to prevent congenital heart block: Findings of a multicenter, prospective, observational study.

OBJECTIVE: Congenital heart block (CHB) is presumed to be caused by transplacental passage of maternal immunoglobulin against Ro and La ribonucleoproteins. The recurrence rate in subsequent pregnancies following the birth of a child with CHB is approximately 19%. The purpose of this study was to determine whether intravenous immunoglobulin (IVIG) therapy could prevent the development of CHB in the fetuses of high-risk pregnant women. METHODS: A total of 24 pregnancies in 22 women who had a previous pregnancy in which CHB developed, were over the age of 18 years, were <12 weeks pregnant, and had anti-Ro, anti-La, or both antibodies were monitored in this multicenter, prospective, observational study. Fifteen patients received infusions of IVIG. The 9 pregnancies in the remaining 7 patients served as controls. IVIG was administered at a dose of 400 mg/kg at weeks 12, 15, 18, 21, and 24 of pregnancy. Echocardiograms were performed at least every 3 weeks from week 15 to week 30 of gestation. Electrocardiograms were obtained at birth. The outcome measure was the development of third-degree CHB detected by fetal echocardiogram. RESULTS: CHB developed in 3 babies among the 15 pregnancies in the treatment group (20%) and in 1 baby among the 9 pregnancies in the control group (11%). CHB was detected at weeks 18, 23, and 26, respectively, in the 3 babies in the treated group and at week 19 in the baby in the control group. Three of the affected pregnancies ended in termination; 2 for reasons related to the fetal disease and 1 for reasons related to both maternal (severe pulmonary hypertension) and fetal disease (at 21 weeks of gestation). CONCLUSION: IVIG at the dose and frequency used in this study was not effective as prophylactic therapy for CHB in high-risk mothers.

BANK1 functional variants are associated with susceptibility to diffuse systemic sclerosis in Caucasians.

OBJECTIVE: To investigate the possible association of the BANK1 gene with genetic susceptibility to systemic sclerosis (SSc) and its subphenotypes. METHODS: A large multicentre case-control association study including 2380 patients with SSc and 3270 healthy controls from six independent case-control sets of Caucasian ancestry (American, Spanish, Dutch, German, Swedish and Italian) was conducted. Three putative functional BANK1 polymorphisms (rs17266594 T/C, rs10516487 G/A, rs3733197 G/A) were selected as genetic markers and genotyped by Taqman 5 allelic discrimination assay. RESULTS: A significant association of the rs10516487 G and rs17266594 T alleles with SSc susceptibility was observed (pooled OR=1.12, 95% CI 1.03 to 1.22; p=0.01 and pooled OR=1.14, 95% CI 1.05 to 1.25; p=0.003, respectively), whereas the rs3733197 genetic variant showed no statistically significant deviation. Stratification for cutaneous SSc phenotype showed that the BANK1 rs10516487 G, rs17266594 T and rs3733197 G alleles were strongly associated with susceptibility to diffuse SSc (dcSSc) (pooled OR=1.20, 95% CI 1.05 to 1.37, p=0.005; pooled OR=1.23, 95% CI 1.08 to 1.41, p=0.001; pooled OR=1.15, 95% CI 1.02 to 1.31, p=0.02, respectively). Similarly, stratification for specific SSc autoantibodies showed that the association of BANK1 rs10516487, rs17266594 and rs3733197 polymorphisms was restricted to the subgroup of patients carrying anti-topoisomerase I antibodies (pooled OR=1.20, 95% CI 1.02 to 1.41, p=0.03; pooled OR=1.24, 95% CI 1.05 to 1.46, p=0.01; pooled OR=1.26, 95% CI 1.07 to 1.47, p=0.004, respectively). CONCLUSION: The results suggest that the BANK1 gene confers susceptibility to SSc in general, and specifically to the dcSSc and anti-topoisomerase I antibody subsets.

Off-label use of rituximab in 196 patients with severe, refractory systemic autoimmune diseases.

OBJECTIVES: To analyse the safety and efficacy of the off-label use of rituximab in patients with severe, refractory systemic autoimmune diseases. METHODS: In 2006, the Study Group on Autoimmune Diseases of the Spanish Society of Internal Medicine created the BIOGEAS project, a multicenter study devoted to collecting data on the use of biological agents in adult patients with systemic autoimmune diseases refractory to standard therapies (failure of at least two immunosuppressive agents). RESULTS: One hundred and ninety-six patients with systemic autoimmune diseases treated with rituximab have been included in the Registry (158 women and 38 men, mean age 43 years). Systemic autoimmune diseases included systemic lupus erythematosus (107 cases), inflammatory myopathies (20 cases), ANCA-related vasculitides (19 cases), Sjögren's syndrome (15 cases) and other diseases (35 cases). A therapeutic response was evaluable in 194 cases: 99 (51%) achieved a complete response, 51 (26%) a partial response and 44 (23%) were classified as non-responders. After a mean follow-up of 27.56+/-1.32 months, 44 (29%) out of the 150 responders patients relapsed. There were 40 adverse events reported in 33 (16%) of the 196 patients. The most frequent adverse events were infections, with 24 episodes being described in 19 patients. Thirteen (7%) patients died, mainly due to disease progression (7 cases) and infection (3 cases). CONCLUSIONS: Although not yet licensed for this use, rituximab is currently used to treat severe, refractory systemic autoimmune diseases, with the most favourable results being observed in Sjögren's syndrome, inflammatory myopathies, systemic lupus erythematosus and cryoglobulinemia.

Investigation of TLR5 and TLR7 as candidate genes for susceptibility to systemic lupus erythematosus.

OBJECTIVES: The aim of this study was to evaluate the relevance of genetic variants of TLR5 (rs5744168) and TLR7 (rs179008) gene in systemic lupus erythematosus (SLE) in a Spanish population. MATERIAL AND METHODS: Our study population consisted of 752 SLE patients and 1107 healthy controls. All individual were of Spanish Caucasian origin. The TLR5 and TLR7 polymorphisms were genotyped using a PCR system with pre-developed TaqMan allelic discrimination assay. RESULTS: No statistically significant differences were observed when the allele and genotype distribution of TLR5 rs5744168 and TLR7 rs179008 polymorphisms was compared between SLE patients and healthy controls. A significant increase frequency in the CC genotype of the TLR5 rs5744168 polymorphism among SLE patients without nephritis was found (93% vs. 87% in SLE patients with nephritis, p=0.03, OR=2.11 95%CI 0.93-3.51). However, this difference did not reach statistical significance in the allele frequencies (p=0.08). CONCLUSION: These results suggest that the tested variations of TLR5 and TLR7 genes do not confer a relevant role in the susceptibility or severity to SLE in the Spanish population.

Screening for PAH in patients with systemic sclerosis: focus on Doppler echocardiography.

It is well established that patients with CTDs such as SSc carry a considerable risk of developing pulmonary arterial hypertension (PAH). Such SSc-PAH patients have an even worse prognosis than patients with only one of these two conditions. In view of the high incidence and prevalence of PAH in SSc, and the available treatment options that improve quality of life, exercise capacity and possibly survival, systematic screening has been recommended. The present article reviews current recommendations from PAH guidelines, focusing on studies that used Doppler echocardiography for screening, and describes limitations associated with the procedure. Furthermore, characteristics and parameters used to identify patients at high risk of developing PAH are summarized.

First clinical symptom as a prognostic factor in systemic sclerosis: results of a retrospective nationwide cohort study.

The objective of the study is to determine the importance of the mode of onset as prognostic factor in systemic sclerosis (SSc). Data were collected from the Spanish Scleroderma Registry (RESCLE), a nationwide retrospective multicenter database created in 2006. As first symptom, we included Raynaud's phenomenon (RP), cutaneous sclerosis, arthralgia/arthritis, puffy hands, interstitial lung disease (ILD), pulmonary arterial hypertension (PAH), and digestive hypomotility. A total of 1625 patients were recruited. One thousand three hundred forty-two patients (83%) presented with RP as first symptom and 283 patients (17%) did not. Survival from first symptom in those patients with RP mode of onset was higher at any time than those with onset as non-Raynaud's phenomenon: 97 vs. 90% at 5 years, 93 vs. 82% at 10 years, 83 vs. 62% at 20 years, and 71 vs. 50% at 30 years (p < 0.001). In multivariate analysis, factors related to mortality were older age at onset, male gender, dcSSc subset, ILD, PAH, scleroderma renal crisis (SRC), heart involvement, and the mode of onset with non-Raynaud's phenomenon, especially in the form of puffy hands or pulmonary involvement. The mode of onset should be considered an independent prognostic factor in systemic sclerosis and, in particular, patients who initially present with non-Raynaud's phenomenon may be considered of poor prognosis.

Functional coupling between neurons and glia.

Neuronal-glial interactions play an important role in information processing in the CNS. Previous studies have indicated that electrotonic coupling between locus ceruleus (LC) neurons is involved in synchronizing the spontaneous activity. The results of the present study extend the functional electrotonic coupling to interactions between neurons and glia. Spontaneous oscillations in the membrane potential were observed in a subset of glia. These oscillations were synchronous with the firing of neurons, insensitive to transmitter receptor antagonists and disrupted by carbenoxolone, a gap junction blocker. Hyperpolarization of neurons with [Met] (5)enkephalin blocked the oscillations in glia. Selective depolarization of glia with a glutamate transporter substrate (l-alpha-aminoadipic acid) increased the neuronal firing rate, suggesting that changes in the membrane potential of glia can modulate neuronal excitability through heterocellular coupling. Dye-coupling experiments further confirmed that small molecules could be transferred through gap junctions between these distinct cell types. No dye transfer was observed between neurons and oligodendrocytes or between astrocytes and oligodendrocytes, suggesting that the junctional communication was specific for astrocytes and neurons. Finally, immunoelectron microscopy studies established that connexins, the proteins that form gap junctions, were present on portions of the plasmalemma, bridging the cytoplasm of neurons and glia in LC. This heterocellular coupling extends the mechanisms by which glia participate in the network properties of the LC in which the degree of coupling is thought to influence cognitive performance.

Registry of the Spanish Network for Systemic Sclerosis: Survival, Prognostic Factors, and Causes of Death.

Systemic sclerosis (SSc) is a rare, multisystem disease showing a large individual variability in disease progression and prognosis. In the present study, we assess survival, causes of death, and risk factors of mortality in a large series of Spanish SSc patients. Consecutive SSc patients fulfilling criteria of the classification by LeRoy were recruited in the survey. Kaplan-Meier and Cox proportional-hazards models were used to analyze survival and to identify predictors of mortality. Among 879 consecutive patients, 138 (15.7%) deaths were registered. Seventy-six out of 138 (55%) deceased patients were due to causes attributed to SSc, and pulmonary hypertension (PH) was the leading cause in 23 (16.6%) patients. Survival rates were 96%, 93%, 83%, and 73% at 5, 10, 20, and 30 years after the first symptom, respectively. Survival rates for diffuse cutaneous SSc (dcSSc) and limited cutaneous SSc were 91%, 86%, 64%, and 39%; and 97%, 95%, 85%, and 81% at 5, 10, 20, and 30 years, respectively (log-rank: 67.63, P < 0.0001). The dcSSc subset, male sex, age at disease onset older than 65 years, digital ulcers, interstitial lung disease (ILD), PH, heart involvement, scleroderma renal crisis (SRC), presence of antitopoisomerase I and absence of anticentromere antibodies, and active capillaroscopic pattern showed reduced survival rate. In a multivariate analysis, older age at disease onset, dcSSc, ILD, PH, and SRC were independent risk factors for mortality. In the present study involving a large cohort of SSc patients, a high prevalence of disease-related causes of death was demonstrated. Older age at disease onset, dcSSc, ILD, PH, and SRC were identified as independent prognostic factors.

Vasoactive intestinal polypeptide induces REM recovery in insomniac forebrain lesioned cats.

Basal forebrain (BF) lesions in cats produces insomnia by reducing both slow wave sleep (SWS) and rapid-eye-movement (REM) sleep time. Recently it has been shown that vasoactive intestinal polypeptide (VIP) may be a specific REM inductor in the parachlorophenylalanine (PCPA) insomniac model. The purpose of this study was to test the hypnogenic properties of VIP in a nonpharmacological model of insomnia. Cats were rendered insomniac by delivering a DC current through stainless steel tripolar electrodes implanted in the basal forebrain area (BFA). Sleep-waking cycle recordings were done prior to lesions and on days 7, 9, 10, 11, 14, and 21 days after BF lesion. On day 10 after the lesion, 200 ng of VIP was injected into the 4th ventricle. Results showed that on postlesion days 7 and 9, SWS and REM sleep total times decreased, while waking time increased significantly. VIP restored REM sleep total time and frequency for almost 48 h, and SWS sleep total time for 24 h. On days 14 and 21 postlesion, insomnia was reestablished. Results are discussed in terms of the possible anatomical and neurochemical substrates whereby VIP can induce the recovery of sleep-waking control values.

Expression of connexins during development and following manipulation of afferent input in the rat locus coeruleus.

Synchronous activity of locus coeruleus (LC) neurons during early postnatal development is regulated, in part, by electrotonic coupling. Connexin (Cx) proteins that make up gap junction channels are localized to both neurons and glia in the LC during this period. In adult rats, however, synchrony exists only under certain experimental conditions. The expression of Cx proteins was examined using western blot analysis at several developmental time points. Immunoblot analysis revealed little to no expression of Cx26 while Cx32, Cx43 and Cx36 were present at all time points examined. A progressive increase in Cx43 was identified from the first postnatal week through adulthood. Immunocytochemical detection of Cx36 and Cx43 in adult LC showed that Cx36 was associated with neuronal processes while Cx43 was localized to glia. In adult LC, in vitro intracellular recordings combined with neurobiotin injections confirmed the presence of gap junctional communication albeit to a lesser extent than in early postnatal periods. The degree to which synaptic inputs to LC neurons impact on Cx protein expression was also evaluated. Samples of the LC from rats that received an electrolytic lesion of the amygdala were processed for western blot analysis of Cx36 and Cx43. The predominantly neuronal Cx36 exhibited an increase in expression while the glial Cx43 was unchanged. The present results indicate that, despite subtype-specific changes during development, several Cx proteins are expressed in the adult LC. In addition, manipulating afferent input to the LC, in adult rats, results in increases in neuronal Cx protein levels but not in glial Cx levels suggesting that altering synaptic inputs to the LC may alter synchronous activity in noradrenergic neurons.

A new motor test sensitive to aging and dopaminergic function.

Neurodegenerative disorders which involve motor impairment is characteristic of old age. Although there are a few tests which attempt to assess motor incapacities, many have utilized scales which have either a great deal of subjective evaluations or are subject to learning-performance complexities. This study describes a method able to measure motor impairment of aging rats which is subject to dopaminergic influences and has negligible practice effects. The test is designed so that rats have to traverse 2 meter beams of 15 degrees inclination whose widths 3, 6, 12, 18 and 24 mm are changed on each test session using a table of random numbers. The time ceiling allowed for traversing the 2 m beams was established at 120 sec. 3-month-old rats (n = 20) and aged rats (n = 20) with a mean age of 26.5 +/- 3.8 months ranging from 23 to 34 months were utilized in this study. All young rats traversed the beams, independently of beam width, while virtually none of the old rats traversed the 3 and 6 mm beams. However, as the beam width increased more and more aged rats ascended the beam. Nevertheless, there were always a few old rats who were unable to cross even on the widest beam. When young rats were fitted with a lead belt which increased their body weight by approximately 40%, they still traversed all beam widths. On the other hand, haloperidol (0.1 and 0.2 mg/kg) severely impaired the performance of young rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Transplantation of the fetal occipital cortex to the third ventricle of SCN-lesioned rats induces a diurnal rhythm in drinking behavior.

Fetal hypothalamic transplants which include the suprachiasmatic nuclei (SCN), were shown previously to be capable of restoring circadian rhythmicity as manifested by both diurnal and free-running rhythms in drinking behavior in rats rendered arrhythmic by SCN lesions. The question arises as to whether the transplant must be homologous tissue or whether any other fetal brain tissue can produce similar effects. In this study rats with a lesion of the SCN and with clear loss of drinking rhythms received grafts of fetal occipital cortex placed into the third ventricle. Following the graft, animals were placed in LD conditions for 8 weeks and then in DD for another 8 weeks. The results indicate that the cortical graft induced recovery of a drinking rhythm under LD lighting conditions but that under DD the rhythm was lost again. These results suggest that non-hypothalamic tissue can mediate recovery of a diurnal rhythm but that hypothalamic tissue including the SCN is required to restore circadian function with maintenance of free-running rhythms.

Dibutyryl cAMP stimulates analgesia in rats bearing a ventricular adrenal medulla transplant.

In the present study, a significant increase in pain threshold (current to elicit vocalization to tail shock) was found 15 and 60 min after injection of dibutyryl cyclic AMP (db cAMP) (30 micrograms) into the lateral ventricle in rats bearing a transplant of fetal adrenal medulla (AM). By contrast, no effect on pain threshold was observed in rats bearing an AM transplant but receiving no db cAMP, or in rats receiving db cAMP but not bearing an AM transplant. In primary cultures of rat fetal chromaffin cells, db cAMP increased the number of neuron-like cells that showed both vasoactive intestinal polypeptide (VIP)- and tyrosine hydroxylase (TH)-like immunoreactivity. These findings indicate that db cAMP exerts a pharmacological modulation of the functional activity (i.e. elevation in pain thresholds) of fetal adrenal AM transplants, and induces phenotypic changes in cultured chromaffin cells with expression of a peptide that elevates pain threshold.

REM sleep enhancement induced by sensory stimulation is prevented by kainic acid lesion of the pontine reticular formation.

It has been shown that auditory or somatic stimulation during rapid eye movement (REM) sleep is capable of producing a significant increase in ponto-geniculo-occipital (PGO) spike density as well as in REM sleep duration. The purpose of this study was to determine the role of the medial pontine reticular formation (PRF) in mediating such increase of REM sleep duration. After a baseline recording whereby on the same recording day the control and the stimulus (auditory or somatic) alternated with each REM, a group of cats was lesioned with kainic acid in the PRF. The sleep-wake cycle was recorded again on days 15, 30 and 45 post-lesion, following the same procedure. The results showed no changes in REM sleep duration and PGO spike density in the lesioned animals. However, when sensory stimulation was applied it was ineffective in producing REM sleep enhancement, although it was able to increase PGO spike density. These findings suggest that the effects of sensory stimulation on REM sleep duration are accomplished through the PRF, probably by inducing an increase in the excitability levels of such neurons, and further suggests that PGO spike density and REM duration are independent of each other.

Fetal suprachiasmatic nucleus transplants: diurnal rhythm recovery of lesioned rats.

The diurnal rhythm organization of drinking behavior was determined prior to and after suprachiasmatic nucleus (SCN) lesions. Five weeks after SCN lesions which produced total loss of the diurnal rhythm, the anterior hypothalamus including the SCN of fetal rats was transplanted into the floor of the 3rd ventricle of the lesioned rats. Eight weeks after the graft, rats recovered their rhythm. The results show that grafts allow animals to recover lost functional properties due to lesions, and further support the notion that the SCN is a pacemaker for certain behaviors.