Association of the autoimmune disease scleroderma with an immunologic response to cancer

Autoimmune diseases are thought to be initiated by exposures to foreign antigens that cross-react with endogenous molecules. Scleroderma is an autoimmune connective tissue disease in which patients make antibodies to a limited group of autoantigens, including RPC1, encoded by the POLR3A gene. As patients with scleroderma and antibodies against RPC1 are at increased risk for cancer, we hypothesized that the "foreign" antigens in this autoimmune disease are encoded by somatically mutated genes in the patients' incipient cancers. Studying cancers from scleroderma patients, we found genetic alterations of the POLR3A locus in six of eight patients with antibodies to RPC1 but not in eight patients without antibodies to RPC1. Analyses of peripheral blood lymphocytes and serum suggested that POLR3A mutations triggered cellular immunity and cross-reactive humoral immune responses. These results offer insight into the pathogenesis of scleroderma and provide support for the idea that acquired immunity helps to control naturally occurring cancers.

Race and association with disease manifestations and mortality in scleroderma: a 20-year experience at the Johns Hopkins Scleroderma Center and review of the literature

Experience suggests that African Americans may express autoimmune disease differently than other racial groups. In the context of systemic sclerosis (scleroderma), we sought to determine whether race was related to a more adverse expression of disease. Between January 1, 1990, and December 31, 2009, a total of 409 African American and 1808 white patients with scleroderma were evaluated at a single university medical center. While the distribution by sex was virtually identical in both groups, at 82% female, African American patients presented to the center at a younger mean age than white patients (47 vs. 53 yr; p < 0.001). Two-thirds of white patients manifested the limited cutaneous subset of disease, whereas the majority of African American patients manifested the diffuse cutaneous subset (p < 0.001). The proportion seropositive for anticentromere antibody was nearly 3-fold greater among white patients, at 34%, compared to African American patients (12%; p < 0.001). Nearly a third of African American (31%) patients had autoantibodies to topoisomerase, compared to 19% of white patients (p = 0.001). Notably, African American patients experienced an increase in prevalence of cardiac (adjusted odds ratio [OR], 1.6; 95% confidence interval [CI], 1.3-2.2), renal (OR, 1.6; 95% CI, 1.2-2.1), digital ischemia (OR, 1.5; 95% CI, 1.4-2.2), muscle (OR, 1.7; 95% CI, 1.3-2.3), and restrictive lung (OR, 6.9; 95% CI, 5.1-9.4) disease. Overall, 700 (32%) patients died (159 African American; 541 white). The cumulative incidence of mortality at 10 years was 43% among African American patients compared to 35% among white patients (log-rank p = 0.0011). Compared to white patients, African American patients experienced an 80% increase in risk of mortality (relative risk [RR], 1.8; 95% CI, 1.4-2.2), after adjustment for age at disease onset and disease duration. Further adjustment by sex, disease subtype, and scleroderma-specific autoantibody status, and for the socioeconomic measures of educational attainment and health insurance status, diminished these risk estimates (RR, 1.3; 95% CI, 1.0-1.6). The heightened risk of mortality persisted in strata defined by age at disease onset, diffuse cutaneous disease, anticentromere seropositivity, decade of care at the center, and among women. These findings support the notion that race is related to a distinct phenotypic profile in scleroderma, and a more unfavorable prognosis among African Americans, warranting heightened diagnostic evaluation and vigilant care of these patients. Further, we provide a chronologic review of the literature regarding race, organ system involvement, and mortality in scleroderma; we furnish synopses of relevant reports, and summarize findings.

The degree of skin involvement identifies distinct lung disease outcomes and survival in systemic sclerosis

OBJECTIVE

To determine whether the pattern of skin involvement can predict clinical features, risk of restrictive lung disease (RLD) and survival in a large scleroderma (SSc) cohort.

METHODS

Demographic and clinical data collected over 30 years from 2205 patients with SSc were retrospectively analysed after subdividing subjects into four subtypes based on pattern of skin fibrosis: type 0 (no skin involvement), type 1 (limited to metacarpophalangeal joints), type 2 (distal to elbows/knees) and type 3 (proximal to elbows/knees). Clinical features associated with skin subsets were identified by regression analyses. Kaplan-Meier and Cox proportional hazards models were used to compare time to RLD and survival across subtypes.

RESULTS

The presence and severity of RLD were positively associated with skin subtype (p<0.001). RLD prevalence incrementally ranged from 51.9% in type 0 to 76.7% in type 3 (p<0.001). Type 2 SSc exhibited a distinct phenotype with intermediate risk for RLD relative to type 1 (higher, p<0.001) and type 3 (lower, p<0.001) and a unique autoantibody profile, with a prevalence of anticentromere antibodies lower than type 1 (28.9% vs 44.1%, p=0.001) and of anti-topoisomerase I antibodies similar to type 3 (32.8% vs 28.7%, p=0.38). These autoantibodies were also found to be significant negative (OR=0.33, p<0.001) and positive (OR=1.6, p=0.01) predictors of RLD risk, respectively. Mortality was also intermediate in type 2 patients relative to type 3 (p=0.0003) and type 1 (p=0.066).

CONCLUSIONS

These data suggest that the current classification subdividing SSc into limited and diffuse cutaneous subtypes misclassifies an intermediate group of patients exhibiting unique autoantibody profile, disease course and clinical outcomes.

Open label study of escalating doses of oral treprostinil diethanolamine in patients with systemic sclerosis and digital ischemia: pharmacokinetics and correlation with digital perfusion

Introduction

Treprostinil diethanolamine is an innovative salt form of the prostacyclin analogue, treprostinil sodium, developed as an oral sustained release (SR) osmotic tablet. The availability of a formulation permitting convenient systemic delivery might have applicability to scleroderma vascular complications. We evaluated pharmacokinetics and perfusion in scleroderma patients with digital ischemia following escalating twice-daily doses of treprostinil diethanolamine SR.

Methods

Scleroderma patients with digital ulcers were enrolled in this dual-center, open-label, phase I pharmacokinetic study. Drug concentrations and perfusion, quantified by laser Doppler imaging, were measured over 12 hours at the 2 mg and 4 mg (or maximally tolerated) doses. Pharmacokinetic parameters were determined from individual plasma concentration versus time profiles using non-compartmental analysis methods. Digital perfusion and skin temperature were modeled as a function of log-transformed drug concentration and other covariates by performing repeated measures analyses using random effects models.

Results

Nineteen scleroderma patients (84% female, 53% limited scleroderma) received treprostinil diethanolamine SR with dose titration up to 4 mg twice daily as tolerated. Peak concentrations (mean maximum plasma concentration (C_max) = 1,176 and 2,107 pg/mL) occurred approximately 3.6 hours after dose administration, and overall exposure (under the plasma concentration-time curve from time 0 to 12 hours post dose (AUC_0-12) = 7,187 and 12,992 hr*pg/mL) was linear between the 2 mg and 4 mg doses. Perfusion and digital skin temperature were positively associated with log-transformed plasma concentration at the 4 mg dose (P = 0.015 and P = 0.013, respectively). The most frequent adverse events were similar to those seen with prostacyclin analogues.

Conclusions

Oral treprostinil diethanolamine was effectively absorbed in patients with scleroderma. Drug administration was temporally associated with improved cutaneous perfusion and temperature. Treprostinil diethanolamine may provide a new therapeutic option for Raynaud's phenomenon and the peripheral vascular disease of scleroderma.

Trial Registration

ClinicalTrials.gov NCT00848939.

Electronic supplementary material

The online version of this article (doi:10.1186/ar4216) contains supplementary material, which is available to authorized users.

Efficacy of Rho kinase inhibitor fasudil in secondary Raynaud's phenomenon

OBJECTIVE

The RhoA/Rho kinase pathway plays a pivotal role in cold-induced vasoconstriction, vascular smooth muscle cells function, and vascular homeostasis. This study evaluates the efficacy of fasudil, a RhoA/Rho kinase inhibitor, to reverse cold-induced vasospasm in patients with Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc; scleroderma).

METHODS

This is a single-center, double-blind, placebo-controlled, randomized, 3-period crossover study of oral fasudil (40 mg or 80 mg) or placebo administered 2 hours before a standardized cold challenge. The fall in skin temperature after the cold challenge and time to recover 50% and 70% of prechallenge digital skin temperature were used as primary outcomes. Digital blood flow assessed by laser Doppler, time to minimum skin temperature, and rate of skin cooling were also measured.

RESULTS

A total of 17 patients with SSc and RP completed the study. After the cold challenge, skin temperatures and the average time (minutes) to recover 50% (7.9 minutes for placebo, 7.5 minutes for fasudil 40 mg, and 8.2 minutes for fasudil 80 mg; P = 0.791) and 70% (18.2 minutes for placebo, 15.0 minutes for fasudil 40 mg, and 17.1 minutes for fasudil 80 mg; P = 0.654) of prechallenge skin temperature were not significantly different across the 3 groups. The digital blood flow measurements were higher in fasudil-treated groups than placebo, but differences were not significant (P = 0.693).

CONCLUSION

Fasudil administered at a single oral dose of 40 mg or 80 mg was not associated with significant benefit in terms of the skin temperature recovery time and the digital blood flow after the cold challenge.

Antibodies recognising sulfated carbohydrates are prevalent in systemic sclerosis and associated with pulmonary vascular disease

BACKGROUND

Glycosylation represents an important modification that regulates biological processes in tissues relevant for disease pathogenesis in systemic sclerosis (SSc), including the endothelium and extracellular matrix. Whether patients with SSc develop antibodies to carbohydrates is not known.

OBJECTIVES

To determine the prevalence and clinical phenotype associated with serum IgG antibodies recognising distinct glycans in patients with SSc.

METHODS

Pooled serum samples from patients with SSc and controls were screened for the presence of specific anticarbohydrate antibodies using a novel array containing over 300 glycans. Antibody titres to 4-sulfated N-acetyl-lactosamine (4S-LacNAc, (4OSO3)Galβ1-4GlcNAc) were determined in 181 individual serum samples from patients with SSc by ELISA and associated with disease phenotype.

RESULTS

4S-LacNAc was identified as a target in pooled SSc serum. Anti-4S-LAcNAc antibodies were detected in 27/181 patients with SSc (14.9%) compared with 1/40 healthy controls (2.5%). Sulfation at position C4 of galactose (4S-LacNAc) was found to be critical for immunogenicity. Anti-4S-LacNAc antibody-positive patients with SSc had a higher prevalence of pulmonary hypertension by echocardiography than anti-4S-LacNAc-negative patients (15/27 (55.7%) vs 49/154 (31.8%), p=0.02) with an OR of 2.6 (95% CI 1.1 to 6.3). Anti-4S-LacNAc-positive patients accounted for 23.4% of all patients with pulmonary hypertension.

CONCLUSION

Serum from patients with SSc contains IgG antibodies targeting distinct sulfated carbohydrates. The presence of anti-4S-LacNAc antibodies is associated with a high prevalence of pulmonary hypertension. These results suggest that specific post-translational carbohydrate modifications may act as important immunogens in SSc and may contribute to disease pathogenesis.

Long-term experience of mycophenolate mofetil for treatment of diffuse cutaneous systemic sclerosis

BACKGROUND

Immunosuppressive therapy may potentially alter the natural disease course of scleroderma. There have been reports of using mycophenolate mofetil (MMF) for the treatment of scleroderma skin disease.

OBJECTIVE

To analyse the experience of using MMF for the treatment of active diffuse cutaneous scleroderma.

METHODS

The authors compared the change in mean modified Rodnan skin scores (mRSS) in an MMF cohort at baseline with scores at 3, 6, 9 and 12 months and with those of historical controls from a pooled analysis of three multicentre randomised clinical trials of recombinant human relaxin, d-penicillamine and oral bovine type I collagen.

RESULTS

Improvement in mRSS after treatment with MMF compared with baseline was seen as early as 3 months and continued through the 12-month follow-up. The mRSS of the MMF cohort was not different from that of the historical controls at 6 months (MMF -3.05 ± 7.4 vs relaxin -4.83 ± 6.99, p=0.059), but was significantly lower at 12 months (MMF -7.59 ± 10.1 vs d-penicillamine -2.47 ± 8.6, p<0.001; collagen -3.4 ± 7.12, p=0.002). General and muscle severity scores and quality of life measures also improved compared with baseline. Pulmonary function remained stable.

CONCLUSIONS

MMF may benefit skin disease in patients with diffuse scleroderma, but prospective studies are required to determine its role.

Immunotherapy of systemic sclerosis

Scleroderma is a multisystem autoimmune disease characterized by an abnormal immune activation associated with the development of underlying vascular and fibrotic disease manifestations. This article highlights the current use of drugs targeting the immune system in scleroderma. Nonselective immunosuppression, and in particular cyclophosphamide, remains the main treatment for progressing skin involvement and active interstitial lung disease. Mycophenolate mofetil is a promising alternative to cyclophosphamide. The use of cyclosporine has been limited by modest efficacy and serious renal toxicity. Newer T-cell (sirolimus and alefacept) and B-cell (rituximab)-targeted therapies have provided some encouraging results in small pilot studies. Hematopoietic stem cell transplantation can be effective for severe fibrotic skin disease, but toxicity remains a concern. Clinical efficacy and safety of antifibrotic treatments (e.g., imatinib) await confirmation. Newer biological agents targeting key molecular or cellular effectors in scleroderma pathogenesis are now available for clinical testing.

Independent association of anti-beta(2)-glycoprotein I antibodies with macrovascular disease and mortality in scleroderma patients

OBJECTIVE

Systemic sclerosis (SSc; scleroderma) is characterized by a unique widespread vascular involvement that can lead to severe digital ischemia, pulmonary arterial hypertension (PAH), or other organ dysfunction. Microthrombotic events and procoagulation factors such as anti-beta2-glycoprotein I (anti-beta2GPI) or anticardiolipin antibodies (aCL) may be implicated in the development of these manifestations. This study was undertaken to investigate whether anti-beta2GPI and aCL are correlated with macrovascular disease, including ischemic digital loss and PAH, in SSc patients.

METHODS

Seventy-five SSc patients with a history of ischemic digital loss and 75 matched SSc controls were evaluated. Anticentromere antibodies (ACAs), anti-beta2GPI, and aCL were measured, and clinical associations were determined using conditional and simple logistic regression models.

RESULTS

Positivity for anti-beta2GPI was significantly more frequent in SSc patients with digital loss than in patients without digital loss (P=0.017), with the IgA isotype of anti-beta2GPI showing the strongest association (odds ratio [OR] 4.0). There was no significant difference in aCL frequency between patients with digital loss and control patients. After adjustment for demographic characteristics, disease type, smoking, and ACA, anti-beta2GPI positivity was significantly associated with active digital ischemia (OR 9.4), echocardiographically evident PAH (OR 4.8), and mortality (OR 2.9). ACA positivity was associated with history of digital loss (OR 3.28), but not with PAH or mortality. History of digital loss was strongly associated with increased mortality (OR 12.5).

CONCLUSION

Anti-beta2GPI is significantly associated with macrovascular disease in SSc and independently predicts mortality. It is unclear whether it has a pathogenetic role or simply reveals the presence of underlying endothelial injury. The use of anti-beta2GPI as a biomarker of vascular disease in SSc should be further explored.

Lack of detection of agonist activity by antibodies to platelet-derived growth factor receptor alpha in a subset of normal and systemic sclerosis patient sera

OBJECTIVE

To investigate whether agonist anti-platelet-derived growth factor receptor alpha (anti-PDGFRalpha) antibodies are present in the serum of patients with systemic sclerosis (SSc; scleroderma).

METHODS

Sera were obtained from healthy subjects and scleroderma patients. An electrochemiluminescence binding assay was performed for detection of serum autoantibodies to PDGFRalpha, PDGFRbeta, epidermal growth factor receptor (EGFR), and colony-stimulating factor receptor 1 (CSFR1). Serum immunoglobulin was purified by protein A/G chromatography. To assess Ig agonist activity, PDGFRalpha-expressing cells were incubated with pure Ig and the level of receptor phosphorylation determined in an enzyme-linked immunoassay, as well as by Western blotting. Ig agonist activity was also assessed in a mitogenic assay and by MAP kinase activation in a PDGFRalpha-expressing cell line.

RESULTS

Sera from 34.3% of the healthy subjects and 32.7% of the SSc patients contained detectable autoantibodies to PDGFRalpha and PDGFRbeta, but not EGFR or CSFR1. Purified Ig from these sera was shown to retain PDGFR binding activity and, at 200-1,000 microg/ml, exhibited no agonist activity in a cell-based PDGFRalpha phosphorylation assay and did not stimulate a mitogenic response or MAP kinase activation in a PDGFRalpha-expressing cell line. Two purified Ig samples that were unable to bind PDGFRalpha did exhibit binding activity to a nonglycosylated form of PDGFRalpha.

CONCLUSION

Although approximately one-third of sera from scleroderma patients contained detectable autoantibodies to PDGFR, these antibodies were not specific to scleroderma, since they were also detected in a similar percentage of samples from normal subjects. PDGFRalpha agonist activity was not demonstrated when purified Ig from these sera was tested in cell-based assays.

T cell polarization identifies distinct clinical phenotypes in scleroderma lung disease

OBJECTIVE

Lung involvement is the leading cause of morbidity and mortality in systemic sclerosis (SSc; scleroderma), and interstitial lung disease (ILD) is the most common pulmonary manifestation. An abnormal profibrotic Th2/Tc2-polarized T cell response is postulated to mediate tissue damage and fibrosis. The aim of this study was to investigate whether a polarized T cell phenotype in SSc is associated with lung disease or other clinical manifestations of SSc.

METHODS

Circulating T cells were characterized by flow cytometry in 62 patients with SSc and 36 healthy control subjects, using antibodies against CD3, CD4, CD8, chemokine receptor CCR5 (Th1/Tc1-specific), and prostaglandin D2 receptor CRTH2 (Th2/Tc2-specific). The ratio between CCR5 and CRTH2 T cell frequencies was used to quantify type 1 (high-ratio) or type 2 (low-ratio) immune polarization.

RESULTS

Patients with SSc exhibited lower CCR5/CRTH2 T cell ratios than those exhibited by control subjects (P<0.0001), indicating a Th2/Tc2-polarized phenotype. Markedly reduced CCR5/CRTH2 T cell ratios were observed in SSc patients with ILD compared with SSc patients without ILD (P<0.0001), particularly in patients with active ILD (P<0.0001) compared with those with stable lung function. Lower CCR5/CRTH2 ratios were strongly associated with a lower value for the percent predicted forced vital capacity (P<0.0001). In patients with an estimated right ventricular systolic pressure>35 mm Hg, suggestive of pulmonary vascular disease, a lower value for the percent predicted diffusing capacity (DLCO) was associated with higher CCR5/CRTH2 T cell ratios (Th1/Tc1) (P=0.009), while in those with right ventricular systolic pressure<35 mm Hg, a lower value for the percent predicted DLCO correlated with lower ratios (Th2/Tc2) (P<0.0001), as observed for ILD.

CONCLUSION

T cell polarization in SSc is strongly associated with specific manifestations of lung disease. Measurement of T cell polarization may represent a valuable tool to monitor disease activity and predict clinical outcomes in SSc patients with lung disease.

Scleroderma-like fibrosing disorders

Many conditions presenting with clinical hard skin and tissue fibrosis can be confused with systemic sclerosis (scleroderma). These disorders have very diverse etiologies and often an unclear pathogenetic mechanism. Distinct clinical characteristics, skin histology, and disease associations may allow one to distinguish these conditions from scleroderma and from each other. A prompt diagnosis is important to spare patients from ineffective treatments and inadequate management. This article highlights nephrogenic systemic fibrosis (nephrogenic fibrosing dermopathy), eosinophilic fasciitis (Shulman's syndrome), scleromyxedema, and scleredema. These often are detected in the primary care setting and referred to rheumatologists for further evaluation. Rheumatologists must be able to promptly recognize them to provide valuable prognostic information and appropriate treatment options for affected patients.

Autoimmunity in systemic sclerosis: current concepts

Systemic sclerosis (SSc) is characterized by tissue fibrosis, obliterative microangiopathy, and immune abnormalities. The role of autoimmunity in generating the clinical and pathologic phenotype in SSc remains uncertain. Distinct subsets of antinuclear antibodies are selectively associated with unique disease manifestations but do not have a proven pathogenic role. A new class of autoantibodies recognizing cellular or extracellular matrix antigens has been recognized in SSc patients. They seem to directly activate pathways that may contribute to SSc-specific tissue and vascular damage. Data confirms that activation and polarization of T cells can contribute to a profibrotic environment. Also, activated immune effector cells can promote vascular obliterative damage through direct cytotoxic pathways targeting the endothelium or by inducing proinflammatory molecules. Technologies are emerging to accurately measure the autoantigen-specific T-cell response in SSc patients. Perturbed B-cell homeostasis has been reported in SSc. If confirmed in-vivo, these advances could lead to new disease-modifying therapeutic strategies directed at SSc-specific immune effector pathways.

Evaluation of topoisomerase-1-specific CD8+ T-cell response in systemic sclerosis

Measurement of disease activity in systemic autoimmune disorders is often unreliable, and immunosuppressive therapy is often titrated to crude clinical response and/or onset of complications. Systemic sclerosis (SSc) presents a distinct clinical phenotype associated with specific autoantibodies. Anti-topoisomerase-1 (SCL-70) is selectively detected in 30-60% of subjects with diffuse skin and interstitial lung involvement. Such patients offer an ideal clinical model to characterize and quantify the autoantigen-specific T-cell response and its correlation with disease phenotype and activity. Human leukocyte antigen A2 (HLA-A2)-restricted topo-1 peptides were selected based on an epitope prediction algorithm. For initial studies, the best binder topo-1(262-270) KMLDHEYTT (#262) was used alone or loaded onto an artificial antigen-presenting platform generated by coupling a dimeric major histocompatibility complex-immunoglobulin G fusion protein (HLA-A2-Ig) and anti-CD28 antibodies onto magnetic beads (artificial antigen-presenting cells). Blood samples (100 microL) from HLA-A2+ SSc patients and cytomegalovirus (CMV) seropositive healthy control subjects were tested in an intracellular cytokine staining assay. Gamma interferon production by CD8+ T cells was measured after stimulation with peptide #262, CMVpp65, or MART-1 (irrelevant peptide). In two of five SCL-70+ patients, peptide #262-loaded aAPCs induced a specific CD8+ T-cell response (0.45% +/- 0.23% of total CD8+ cells). This response was not observed in the seven SCL-70- (five SSc and two CMV+) control subjects studied (0.03% +/- 0.02%). Interestingly, bronchoalveolar lavage fluid obtained from one topo-1-responsive SSc patient who had worsening respiratory function and active alveolitis showed striking enrichment of topo-1-specific CD8+ T cells (3.94%). This small-volume ex vivo assay may prove to be a sensitive and specific tool to assess disease activity and to monitor response to therapy in patients with scleroderma.

Understanding, assessing and treating Raynaud's phenomenon

PURPOSE OF REVIEW

New insights in the pathophysiology and molecular mechanisms implicated in cutaneous vasomotor response to cooling are emerging from recent literature. These advances are introducing significant changes in the management of Raynaud's phenomenon. In this review, we outline how these new findings are leading to novel methods of assessment and new opportunities for specific targeted therapy.

RECENT FINDINGS

New potential targets for treatment of Raynaud's phenomenon derive from experimental observations. Increased protein tyrosine kinase activity and tyrosine phosphorylation have been described in vascular smooth muscle cells in response to cooling and are linked to excessive alpha2-adrenergic response. Activation of Rho/Rho kinase pathway is triggered by increase of reactive oxygen species and up-regulates alpha2c-adrenergic receptors on the surface of vascular smooth muscle cells, thus determining an excessive vasoconstrictive response to cooling. This observation generated pilot trials testing rho-kinase inhibitors and alpha2c-adrenergic receptors antagonists in vasospastic conditions with encouraging results. Therapies already in use for pulmonary hypertension are also showing an effect in Raynaud's phenomenon. Studies evaluating anti-endothelin-1 (bosentan), phosphodiesterases inhibitors (sildenafil), and prostanoids (given for critical digital ischemia) in the treatment of Raynaud's phenomenon all determined improvement of symptoms and/or digital ischemic lesions. Novel techniques for better visualization and quantification of cutaneous microvascular defects are under development. The hope is that these new tools will allow earlier discrimination between primary and secondary Raynaud's phenomenon as well as a better way to predict outcome and response to therapy.

SUMMARY

Remarkable progress towards a rational approach to the management and treatment of Raynaud's phenomenon is emerging.

Role of CREB transcription factor in c-fos activation in natural killer cells

In natural killer (NK) cells, interleukin-2 (IL-2) differentially regulates the expression of several transcription factors, including JunB and c-fos. The cAMP response element binding protein, CREB, is a key transcriptional regulator of a large number of genes containing the octanucleotide CRE consensus sequence in their upstream regulatory regions. We studied here the functional role of CREB in the IL-2-mediated transcriptional regulation of c-fos in human NK cells. Our results show that IL-2 activates CREB in human NK cells and that CREB activation hasa prominent regulatory role on the IL-2-induced expression of functional c-fos and AP-1 in NK cells. We identify two domains of the c-fos promoter, containing three CRE sites, which are critical for the transcriptional activity induced by IL-2. The first domain is located within the first 220 nucleotides of the c-fos promoter, while the second encompasses the nucleotides - 440 and - 220. Our results show that CREB has a relevant role in the cytokine-mediated activation of NK cells, and are particularly remarkable in the light of the several genes that are positively regulated by c-fos and AP-1, such as IFN-gamma, IL-2 and GM-CSF genes.

Increased serum interleukin-8 and interleukin-10 in schizophrenic patients resistant to treatment with neuroleptics and the stimulatory effects of clozapine on serum leukemia inhibitory factor receptor

There is now evidence that schizophrenia may be accompanied by an activation of the monocytic and T-helper-2 (Th-2) arms of cell-mediated immunity (CMI) and by various alterations in the Th-1 arm of CMI. There is also evidence that repeated administration of typical and atypical antipsychotics may result in negative immunomodulatory effects. This study was carried out to examine (1) the serum concentrations of interleukin-8 (IL-8), IL-10, the soluble CD8 (sCD8) and the leukemia inhibitory factor receptor (LIF-R) in nonresponders to treatment with typical neuroleptics as compared with normal volunteers and responders to treatment; and (2) the effects of atypical antipsychotics on the above immune variables. The latter were determined in 17 nonresponders to treatment with neuroleptics and in seven normal volunteers and 14 schizophrenic patients who had a good response to treatment with antipsychotic agents. The nonresponders had repeated measurements of the immune variables before, and 2 and 4 months after treatment with clozapine or risperidone. Serum IL-8 and IL-10 were significantly higher in schizophrenic patients than in normal controls. The serum concentrations of the sCD8 were significantly increased 2 months, but not 4 months, after starting treatment with atypical antipsychotics. Serum LIF-R concentrations were significantly increased 2 and 4 months after starting treatment with atypical antipsychotics. It is concluded that: (1) schizophrenia is characterized by an activation of both pro-inflammatory and anti-inflammatory aspects of cell-mediated immunity; (2) prolonged treatment with atypical antipsychotics may increase the anti-inflammatory capacity of the serum in schizophrenic patients by increasing serum LIF-R concentrations; and (3) short-term treatment with clozapine may induce signs of immune activation which disappear upon prolonged treatment.

Association between promoter polymorphic haplotypes of interleukin-10 gene and schizophrenia

BACKGROUND

Schizophrenia is one of the most severe psychiatric disorders, with a worldwide incidence of 1%. Several reports show abnormal cytokine levels in psychotic patients and indicate a possible role of the immune response system in the pathogenesis of schizophrenia. Increased concentrations of interleukin 10 (IL-10) have been found in plasma of schizophrenic patients, suggesting its potential role as a candidate gene for susceptibility to schizophrenia. IL-10 gene maps on chromosome 1 (q31-q32), a locus associated with genetic susceptibility to schizophrenia. Three functional haplotypes of the gene (GCC, ACC, ATA) have been described, derived from different combinations of three "single nucleotide polymorphisms" and directly related to the expression levels of the protein.

METHODS

We analyzed allele, genotype, and haplotype distributions in an association case-control study involving 106 schizophrenic patients and 143 unrelated healthy volunteers using polymerase chain reaction (PCR)-Single Strand Conformation Polymorphism and PCR Restriction Fragment Length Polymorphism methods.

RESULTS

Our results show a significant increase of GCC homozygotes (the high IL-10-producing haplotype) in schizophrenic patients compared to control subjects (chi(2) = 13, p =.023; odds ratio = 3.03; 95% confidence interval, 1.274-7.355).

CONCLUSIONS

These data could partly explain the abnormal secretion of IL-10 occurring in schizophrenic patients in response to infections or different stressors and suggest a potential role of IL-10 as a candidate gene for susceptibility to schizophrenia.

Association between -G308A tumor necrosis factor alpha gene polymorphism and schizophrenia

Dysregulation of the inflammatory response system has been linked to pathophysiology of schizophrenia. Evidence of immune activation has derived from the detection of abnormal levels of proinflammatory cytokines and their receptors in peripheral blood and cerebrospinal fluid from schizophrenic patients. Cytokines are involved in normal CNS development as well as in the pathogenesis of many neuro-psychiatric disorders, acting directly on neural cells or modulating neurotransmitter and neuropeptide systems. In particular tumor necrosis factor alpha (TNFalpha), depending on its concentration, can exert both neurotrophic and neurotoxic effects and influence neural cell growth and proliferation. Moreover, TNFalpha gene is located on the small arm of chromosome 6 (6p21.1-21.3), a locus associated with genetic susceptibility to schizophrenia. We studied the distribution of -G308A TNFalpha gene polymorphism in 84 schizophrenic patients and in 138 healthy volunteers. This biallelic base exchange polymorphism directly affects TNFalpha plasma levels. Frequency of the TNF2(A) allele is significantly increased in schizophrenic patients as compared to controls (P = 0.0042). Genotype distribution is also significantly different (P = 0.0024). TNF2 homozygotes are represented only in the patient group (P = 0.002). These data suggest a potential role of TNFalpha as a candidate gene for susceptibility to schizophrenia and suggest that immune dysregulation in schizophrenic patients could also have a genetic component.

Effects of atypical antipsychotics on the inflammatory response system in schizophrenic patients resistant to treatment with typical neuroleptics

There is now some evidence that schizophrenia may be accompanied by an activation of the inflammatory response system (IRS) and that typical antipsychotics may suppress some signs of IRS activation in that illness. This study was carried out to examine (i) the serum concentrations of interleukin-6 (IL-6), IL-6 receptor (IL-6R), IL-1R antagonist (IL-1RA) and Clara Cell protein (CC16), an endogenous anticytokine, in nonresponders to treatment with typical neuroleptics and (ii) the effects of atypical antipsychotics on the above IRS variables. The above parameters were determined in 17 patients with treatment-resistant schizophrenia (TRS) to treatment with neuroleptics and in seven normal volunteers and 14 schizophrenic patients who had a good response to treatment with antipsychotic agents. Patients with TRS had repeated measurements of the IRS variables before and 2 and 4 months after treatment with atypical antipsychotics. Serum IL-6 was significantly higher in schizophrenic patients, irrespective of their response to typical antipsychotics, than in normal controls. Serum IL-1RA was significantly higher in the TRS patients than in controls, whereas responders took up an intermediate position. The serum concentrations of CC16 were significantly lower after treatment with atypical antipsychotics during 4 months than before treatment. It is concluded that (i) schizophrenia and, in particular, TRS is characterized by an activation of the monocytic arm of cell-mediated immunity and (ii) atypical antipsychotics may decrease the anti-inflammatory capacity of the serum in TRS patients.