Serum sCTLA-4 Levels Research Articles

Soluble cytotoxic T-lymphocyte antigen-4 (sCTLA-4) in children with immune cytopenia: relation to disease activity

Cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) is a costimulatory receptor exhibiting a potent inhibitory signal on antigen-activated immune responses. A soluble form, sCTLA-4, has been identified and was found to be increased in several autoimmune diseases. We aimed to evaluate serum levels of sCTLA-4 in different immune cytopenias, and to determine its possible relation to the disease activity. We measured serum levels of sCTLA-4 in 47 patients with immune cytopenias and compared them to 47 age- and sex-matched healthy controls. sCTLA-4 levels were significantly higher in patients with immune cytopenias compared to healthy controls (p < 0.001), however, levels were comparable between different groups of immune cytopenias (p = 0.084). Serum sCTLA-4 inversely correlated with age at diagnosis and hemoglobin level (p = 0.048, and p = 0.039 respectively), while it directly correlated with disease duration (p = 0.023) as well as markers of hemolysis including reticulocyte count, serum LDH and indirect bilirubin (p = 0.025; p = 0.019; p = 0.004 respectively). In the AIHA group, serum sCTLA-4 levels were significantly lower in patients in remission compared to patients with active disease (p = 0.026). Children with immune cytopenia exhibit significantly higher levels of circulating sCTLA-4 which correlated with disease activity, yet the prognostic significance and its use to tailor treatment regimen require additional studies.

Correlation between sCTLA-4 and sCD86 Levels with Disease Activity of Systemic Lupus Erythematosus (SLE) Patients Based on SLEDAI Score

Background. Systemic Lupus Erythematosus (SLE) is an autoimmune disease with multisystem involvement which arises from multifactorial causes. Continuous exposure to autoantigens and chronic activation of the immune system, especially memory T lymphocytes, contribute to premature immunosenescence. sCTLA-4 and sCD86 are soluble costimulatory molecules of CTLA-4 and CD86, which play a role in the occurrence of immunosenescence in SLE. The presence of immunosenescence will cause higher morbidity and mortality. This research was conducted to establish the correlation between the increased levels of sCTLA-4 and sCD86 and the severity of SLE, as measured by the SLE Disease Activity Index (SLEDAI) score. Methods. This analytical observational research utilized a cross-sectional approach involving 35 female SLE patients diagnosed according to the SLICC 2012 criteria. SLE disease activity was measured using SLEDAI score. Serum sCTLA-4 and sCD86 levels were measured using the ELISA method. Statistical analysis was conducted using the Mann-Whitney test for comparisons and the Spearman test for correlation analysis, with a significance level of p&lt;0.05. Results. sCTLA-4 levels were higher and significantly different in patients with moderate SLE (p=&lt;0.001; p&lt;0.05), and there was no significant difference in sCD86 levels (p=0.915; p&gt;0.05). Increased sCTLA-4 levels were positively correlated with the severity of SLE (r =0.361, p=0.033), while no significant correlation was observed in sCD86 levels (r=-0.094, p=0.591). Conclusion. Elevated sCTLA-4 levels were positively correlated with increased severity of SLE based on the SLEDAI score.

Assessment of CTLA-4 Gene Expression Levels on CD8+ T Cells in Renal Transplant Patients and Relation with Serum sCTLA-4 Levels.

CTLA-4 (Cytotoxic T Lymphocyte Antigen-4) is an immune regulator molecule that is expressed on a variety of immune cells, including CD4+ and CD8+ T cells. After realizing the significance of this regulator molecule, researchers began to concentrate on its activation or inhibition in cancer. Even though there have been some studies on organ transplantation and autoimmunity, the role of the CTLA-4 molecule in renal transplantation has not been demonstrated. The goal of this study was to see how CTLA-4 gene expression and serum sCTLA-4 levels affected renal transplant patients. Peripheral blood samples were collected before and 1-3 months after renal transplantation from 29 recipients.CD8+ T lymphocytes were separated using magnetic beads and purity of the cells controlled by Flow cytometry. CTLA-4 mRNA levels were determined by Real-Time PCR while serum sCTLA-4 levels were assessed by ELISA. 55% of the patient had decreased level of CTLA-4 mRNA after transplantation when compared to pre-transplantation levels. Moreover 61% of the patient had lower serum sCTLA-4 levels after transplantation. sCTLA-4 levels were decreased 11% of the patients with rejection episode after transplantation when compared to stabile patients (5%). Kidney rejection is a complicated process influenced by numerous unknown factors. Several parameters should be evaluated together to precise rejection episodes or graft dysfunctions. Further research focused on the other immune checkpoint regulator molecules could give an opportunity to have an idea about the effect of these molecules on renal transplantation.

Serum Soluble Cytotoxic T-Lymphocyte-Associated Antigen 4 in Children and Adolescents with Autoimmune Cytopenia

Abstract Background Autoimmune cytopenias are characterized by the production of autoantibodies against differentiated hematopoietic cells because of defects in central and/or peripheral tolerance. It includes autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), autoimmune proliferative syndrome (ALPS) and Evans syndrome (EV). Aim of the Work to compare levels of sCTLA-4 in different types of immune cytopenias and their control. Patients and Methods Forty seven children and adolescents who have autoimmune cytopenias were recruited and assessed for eligibility in Pediatric Hematology Clinic, Ain Shams University Children’s Hospital and forming a patients group with age range 8 – 204 months old. An age and sex matched healthy control group were recruited including forty seven healthy participants with age range 6 – 156 months old. Results On initial examination in our study, the prevalence of hepatosplenomegaly and lymphadenopathy among the patients group was 27.7% and 2.1% respectively. Autoimmune cytopenic patients group have statistically significant higher serum sCTLA-4 levels (range 1 – 82 ng/ml) than control group (range 0 – 9 ng/ml) (where P &amp;lt; 0.01 HS). On the other hand, there was no significant difference when comparing levels of sCTLA-4 between sera of ITP, AIHA and ALPS patients (P &amp;gt; 0.05). Serum sCTLA-4 was inversely related to the age at diagnosis and positively related to disease duration. Our results demonstrated the presence of correlations between the levels of sCTLA4 and the severity of autoimmune cytopenias (negative correlation with Hemoglobin (R= -0.315; P = 0.031), mean Hemoglobin (last year) (R= -0.471; P = 0.001) and platelet (R= -0.324; P &amp;lt; 0.05)) and (positive correlation between levels of sCTLA-4 and Reticulocyte count (R = 0.413; P = 0.004), Indirect Bilirubin (R = 0.427; P = 0.003) and Lactate dehydrogenase (R = 0.357; P = 0.014)). There was a significant differences in the prevalence of hepatosplenomegaly among ITP, AIHA and ALPS patients (P &amp;lt; 0.05) with higher prevalence among ALPS patients. Conclusion Soluble form of CTLA4 (sCTLA4) presents in elevated levels in the sera of children and adolescents who have autoimmune cytopenia including AIHA/Evans, ITP and ALPS compared to healthy control group that suggests sCTLA4 could play a role in the pathogenesis of immune cytopenias.

Soluble cytotoxic T-lymphocyte\u2013associated antigen 4 (sCTLA-4) as a potential biomarker for diagnosis and evaluation of the prognosis in Glioma

BackgroundThe cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) is widely considered as a pivotal immune checkpoint molecule to suppress antitumor immunity. However, the significance of soluble CTLA-4 (sCTLA-4) remains unclear in the patients with brain glioma. Here we aimed to investigate the significance of serum sCTLA-4 levels as a noninvasive biomarker for diagnosis and evaluation of the prognosis in glioma patients.MethodsIn this study, the levels of sCTLA-4 in serum from 50 patients diagnosed with different grade gliomas including preoperative and postoperative, and 50 healthy individuals were measured by an enzyme-linked immunosorbent assay (ELISA). And then ROC curve analysis and survival analyses were performed to explore the clinical significance of sCTLA-4.ResultsSerum sCTLA-4 levels were significantly increased in patients with glioma compared to that of healthy individuals, and which was also positively correlated with the tumor grade. ROC curve analysis showed that the best cutoff value for sCTLA-4 for glioma is 112.1 pg/ml, as well as the sensitivity and specificity with 82.0 and 78.0%, respectively, and a cut-off value of 220.43 pg/ml was best distinguished in patients between low-grade glioma group and high-grade glioma group with sensitivity 73.1% and specificity 79.2%. Survival analysis revealed that the patients with high sCTLA-4 levels (> 189.64 pg/ml) had shorter progression-free survival (PFS) compared to those with low sCTLA-4 levels (≤189.64 pg/ml). In the univariate analysis, elder, high-grade tumor, high sCTLA-4 levels and high Ki-67 index were significantly associated with shorter PFS. In the multivariate analysis, sCTLA-4 levels and tumor grade remained an independent prognostic factor.ConclusionThese findings indicated that serum sCTLA-4 levels play a critical role in the pathogenesis and development of glioma, which might become a valuable predictive biomarker for supplementary diagnosis and evaluation of the progress and prognosis in glioma.

Serum sCTLA-4 level is not associated with type 1 diabetes or the coexistence of autoantibodies in children and adolescent patients from the southern region of Saudi Arabia

BackgroundThe soluble form of CTLA-4 (sCTLA-4) is associated with several autoimmune diseases. The aim of the study is to measure the serum sCTLA-4 levels in type I diabetic (T1DM) patients and to assess the presence of autoantibodies for a possible association.MethodsOne hundred forty-two T1DM patients were enrolled in the study. Fifty of them were serologically positive for co-existing autoantibodies. One hundred and five subjects were enrolled in the study, as non-diabetic controls (1–17 years of age; median age—10 years). The serum samples of all the subjects were analyzed with ELISA to detect the concentration of sCTLA-4 and anti-GAD/IA2 IgG. Standard statistical analysis was conducted as required.ResultsNinety-four (66%) subjects of T1DM patients and five (4.7%) subjects of the non-diabetic group had antibodies positive for anti-GAD/IA2. Serum sCTLA-4 was low in most of the subjects of both the diabetic and control groups (p = 0.18). In the control group, nine individuals (8.6%) were positive for sCTLA-4. Similarly, only seven patients (4.9%) in the T1DM group had high levels of sCTLA-4, of which two were found to be double positive for anti-thyroid peroxidase and anti-thyroglobulin antibodies. In addition, among the T1DM patients, no significant relationships were observed between sCTLA-4 levels and age of onset (p = 0.43), disease duration (p = 0.09), or glycemic control (p = 0.32).ConclusionDespite the previous findings of high sCTLA-4 levels in autoimmune diseases, serum levels of sCTLA-4 are not significantly different between T1DM patients and non-diabetic adolescents. Furthermore, we did not observe any association with autoantibody presence, glycemic control, or disease duration.

Urine and serum ghrelin, sCD80 and sCTLA-4 levels in doxorubicin-induced experimental nephrotic syndrome.

Nephrotic syndrome (NS) is an immune-mediated disorder associated with hyperlipidemia. NS has been proposed to be mediated through CD80-related T cell immune response, which could be blocked using soluble cytotoxic T lymphocyte-associated s(CTLA)-4. Although ghrelin is a hormone-modulating lipid metabolism and suppressing immune system, the precise role of ghrelin in NS is not well established. We evaluated the levels of ghrelin, soluble CD80 (sCD80) and sCTLA4 in serum and urine in doxorubicin-induced NS in rats. We also investigated the relation between their levels and the levels of serum total cholesterol (TC), triglyceride, albumin and urine protein. While urinary ghrelin levels were significantly lower in the nephrotic rats compared to the control group, serum ghrelin levels were comparable in the nephrotic and control rats. In contrast, serum and urinary sCD80 and sCTLA4 levels were higher in the nephrotic rats than the controls. The urinary ghrelin levels were negatively correlated with the levels of serum triglyceride, TC and urine protein, sCD80 and sCTLA4. The urine sCD80 levels were positively correlated with the TC, urine protein and urine sCTLA4 levels, and negatively correlated with the serum albumin. The urine sCTLA4 levels were positively correlated with the TC and urine protein levels and negatively correlated with the serum albumin levels. In regression analysis, the urine ghrelin levels significantly relate to urine sCD80 levels. Besides, hyperlipidemia in NS did not appear to be related to serum ghrelin levels. Low urine ghrelin levels might be relevant to pathogenesis of doxorubicin-induced NS. The reduction in urine ghrelin levels might also be associated with increased levels of urine sCTLA4 and sCD80 which reflect proteinuria.

Clinical Benefit from Ipilimumab Therapy in Melanoma Patients may be Associated with Serum CTLA4 Levels.

Stage IV metastatic melanoma patients historically have a poor prognosis with 5–10% 5-year survival. Ipilimumab, a monoclonal antibody against cytotoxic T-lymphocyte antigen 4 (CTLA4), is one of the first treatments to provide beneficial durable responses in advanced melanoma. However, less than 25% of those treated benefit, treatment is expensive, and side effects can be fatal. Since soluble (s) CTLA4 may mediate inhibitory effects previously ascribed to the membrane-bound isoform (mCTLA4), we hypothesized patients benefiting from ipilimumab have higher serum levels of sCTLA4. We found that higher sCTLA4 levels correlated both with response and improved survival in patients treated with ipilimumab in a small patient cohort [patients with (n = 9) and without (n = 5) clinical benefit]. sCTLA4 levels were statistically higher in ipilimumab-treated patients with response to ipilimumab. In contrast, sCTLA4 levels did not correlate with survival in patients who did not receive ipilimumab (n = 11). These preliminary observations provide a previously unrecognized link between serum sCTLA4 levels and response to ipilimumab as well as to improved survival in ipilimumab-treated melanoma patients and a potential mechanism by which ipilimumab functions.

Oversecretion of Soluble CTLA-4 in Various Autoimmune Diseases Overlapping Celiac Disease

To evaluate the levels of soluble CTLA-4 (sCTLA-4) in sera of celiac disease (CD) patients with overlapping autoimmune diseases (OAD; diabetes mellitus, autoimmune thyroid diseases, inflammatory bowel diseases, and autoimmune polyendocrine syndromes). Sera from Italian patients with CD were obtained and enzyme-linked immunosorbent assay was used to measure sCTLA-4. Consistently high serum sCTLA-4 levels were observed in CD (13.20 ng/mL, p<0.0001) and OAD (19.48 ng/mL, p<0.0001) compared to normal controls. A significant increase in the level of serum sCTLA-4 was observed in OAD (p=0.0273) compared to CD alone. At variance, no significant difference in the sCTLA-4 levels was observed when single OAD were compared. The present study shows for the first time a statistically significant increase of serum sCTLA-4 levels in CD patients with associated autoimmune disease (namely, CD and OAD) versus patients with CD alone. Previously, the potential genetic associations of several CTLA-4 polymorphisms to susceptibility to autoimmune diseases have been described, although the relationship between CTLA-4 polymorphisms and the ability to produce the soluble form is not fully clarified. CTLA-4 is a strong actor in the adaptive response: our data give supportive evidence of the common background of autoimmune diseases.

Overexpression and Secretion of the Soluble CTLA-4 Splice Variant in Various Autoimmune Diseases and in Cases with Overlapping Autoimmunity

To explore the potential genetic association of CTLA-4 Exon1 +49A/G and 3'UTR (AT)(n) to susceptibility to systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and overlapping (OP) autoimmunity; affected with more than one autoimmune disease. Expression of two major CTLA-4 isoforms; full length (mCTLA-4) and soluble (sCTLA-4) were explored in all subjects. A total of 680-age/gender/ethnically matched Kuwaitis were recruited and polymerase chain reaction (PCR)-fragment analysis was employed for genotyping both markers. mCTLA-4 and sCTLA-4 mRNA expression were analyzed using quantitative real time-PCR. The enzyme-linked immunosorbent assay (ELISA) was used to screen sCTLA-4 in all subjects' sera. Only two CTLA-4 3'UTR (AT)(n) allelotypes; (AT)(15) and (AT)(6) were detected. The heterozygous (AT)(15/6) genotype confers protectivity rather than susceptibility to SLE (p=0.01, odds ratio=0.43, and confidence interval=0.21-0.86). No significant association was observed between Exon 1 +49A/G and any of the tested diseases. A consistently high serum sCTLA-4 level was observed in RA (6.8 ng/mL, p=0.005), SLE (6.34 ng/mL, p=0.007), and OP (8.75 ng/mL, p=0.012) compared to healthy control. A significant increase in the expression of sCTLA-4 mRNA was observed in OP (p=0.05) and SLE (p=0.047), while a significant increase in the expression of mCTLA-4 (p=0.01) was observed only in OP. The present study is the first to report a statistically significant association between OP and serum sCTLA-4. The novelty of our study is the significance of CTLA-4 in the pathogenesis of OP besides SLE and RA.

Association of cytotoxic T lymphocyte associated antigen‐4 gene (rs60872763) polymorphism with Crohn's disease and high levels of serum sCTLA‐4 in Crohn's disease

Our aim was to evaluate cytotoxic T lymphocyte associated antigen-4 (CTLA-4) gene polymorphisms in Crohn's disease (CD) and explore soluble CTLA-4 (sCTLA-4) levels in serum of CD patients in central China. A total of 126 Chinese CD patients and 300 healthy controls were enrolled in this study. CTLA-4 (AT)n repeat polymorphism was genotyped by a semiautomatic fluorescently labeled polymerase chain reaction (PCR) method, and CTLA-4 -1661A/G and -1722T/C polymorphisms were genotyped by DNA sequencing. Serum sCTLA-4 and C-reactive protein (CRP) levels were determined by enzyme linked immunosorbent assay (ELISA) and immunonephelometry, respectively. The frequency of 84 bp allele of CTLA-4 (AT)n repeats was lower in CD patients than in the healthy controls (22.2% vs 33.2%, P = 0.001, odds ratio = 0.58, 95% confidence interval: 0.41-0.81). The 84 bp allele carriers of (AT)n repeats were associated with non-stricturing and non-penetrating disease behavior in CD patients (P = 0.007). Serum sCTLA-4 levels were more elevated in CD patients than in the healthy controls (P < 0.001). Among CD patients, serum sCTLA-4 levels were increased in active disease compared with inactive disease (P = 0.015), and were correlated with CRP levels (r = 0.524, P < 0.001). Serum sCTLA-4 levels were higher in CD patients with stricturing disease behavior than in patients with other disease behaviors (P = 0.009). 84 bp allele of CTLA-4 (AT)n repeat polymorphism was associated with CD in central China. sCTLA-4 levels were highly expressed in CD, especially in active disease, and were correlated with CRP levels and disease behavior in CD patients.

Soluble CTLA-4 receptor an immunological marker of Graves' disease and severity of ophthalmopathy is associated with CTLA-4 Jo31 and CT60 gene polymorphisms

Graves' disease (GD) is an autoimmune disorder with genetic and environmental background. CTLA-4 is a candidate gene for thyroid autoimmunity. Increased serum levels of soluble CTLA-4 (sCTLA-4) were found in some autoimmune diseases. The aim of the study was to evaluate the relation between sCTLA-4 level and clinical manifestation of Graves' ophthalmopathy (GO), thyroid status, and CTLA-4 gene polymorphisms. Serum sCTLA-4 concentrations were determined in 93 GO patients and 93 healthy controls. In the GO group, CTLA-4 gene was genotyped in five polymorphic sites: g.319C>T, c.49A>G, CT60 by means of PRC-RFLP, Jo31, and g.*642AT(8_33) by means of minisequencing assay. Serum sCTLA-4 level was significantly higher in the GO group than in controls (median: 7.94 vs 0.00 ng/ml, P=0.000001). This level was higher in severe than in nonsevere GO (median: 10.3 vs 5.6 ng/ml, P=0.01). sCTLA-4 concentration was related neither to the activity of GO nor to thyroid function. Elevated sCTLA-4 levels were observed in carriers Jo31[G] allele (genotype GG+GT) as compared with subjects with an absence of the [G] allele (TT genotype; median: 9.18 vs 4.0 ng/ml, P=0.02). Also patients possessing CT60[G] allele (genotype GG+GA) had higher serum sCTLA-4 levels than subjects who lack the [G] allele (AA genotype; median: 8.73 vs 2.28 ng/ml, P=0.03). It was shown for the first time that increased serum concentration of sCTLA-4 correlate with the severity of GO. Genetic variation in the CTLA-4 gene region in GD patients at least partially determines the level of sCTLA-4.

CTLA4 gene polymorphisms and soluble CTLA4 protein in Behcet’s disease

Cytotoxic T lymphocyte antigen 4 (CTLA4; CD152) is a costimulatory molecule expressed on activated T cells that plays a key inhibitory role during T lymphocyte activation. The gene encoding for CTLA4 has been suggested as a candidate for conferring susceptibility to autoinflammatory diseases. We investigated the polymorphisms of the CTLA4 gene [promoter region (-1722 T/C, -1661 A/G and -318 C/T) and exon 1 (+49 G/A)] and the differences of serum soluble sCTLA4 levels in 285 patients with Behcet's disease (BD) and 287 controls. The frequency of the CTLA4 -1661 GG genotype was significantly higher in BD patients than in controls [P = 0.019, odds ratio (OR) = 5.2, 95% confidence interval (CI) = 1.13-23.86]. Also, the genotype frequency for CTLA4 -1722 TC was significantly higher (P = 0.014, OR = 1.8, 95% CI = 1.13-2.99), while CTLA4 -1722 CC was significantly lower (P = 0.018, OR = 0.4, 95% CI = 0.20-0.87) in BD patients with ocular lesions compared with patients without this symptom. Serum sCTLA4 levels in BD patients were significantly lower, especially in BD patients with the CTLA4 +49 G allele, than those in healthy controls (P < 0.05). Although our understanding of the role of the CTLA4 gene and its protein product in BD is incomplete, these results suggest that single nucleotide polymorphisms of the promoter and exon regions in the CTLA4 gene are candidates that predispose to BD and that sCTLA4 may be related to the immunological abnormalities and disease expressions associated with BD.

A functional soluble form of CTLA-4 is present in the serum of celiac patients and correlates with mucosal injury

Celiac disease (CD) is a multifactorial disorder influenced by environmental, genetic and immunological factors. Increasing evidence showed CTLA-4 gene as an important susceptibility locus for autoimmune disorders. A native soluble cytotoxic T-lymphocyte-associated protein-4 (sCTLA-4), lacking of transmembrane sequence, has been described in several autoimmune diseases. We aimed to evaluate the presence of increased sCTLA-4 concentration in the serum of patients with CD and the possible immunoregulatory function. Blood samples were collected from 160 CD patients; sCTLA-4 levels were evaluated by ELISA, western blot and reverse transcription-PCR. The capability of serum sCTLA-4 to modulate T-lymphocyte proliferation in vitro was evaluated by two-way mixed leukocyte reaction assay. We demonstrated high levels of sCTLA-4 in serum of untreated celiac patients. Additionally, we observed that sCTLA-4 concentrations are related to gluten intake and that a correlation between autoantibodies to tissue transglutaminase and sCTLA-4 concentration exists. Moreover, sCTLA-4 levels correlate with the degree of mucosal damage. Conversely, no correlation between sCTLA4 levels and the HLA-related risk was observed. Finally, we show that sCTLA-4 from sera of CD patients displays functional activities. These results strongly suggest a regulation of sCTLA-4 synthesis depending on the presence or absence of dietary gluten and imply a possible immunomodulatory effect on cytotoxic T lymphocyte functions. In gluten-exposed patients, serum sCTLA-4 levels might provide insight about mucosal injury.

Interactions between programmed death 1 (PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) gene polymorphisms in type 1 diabetes

Aim To explore the contribution of the PD-1 gene polymorphisms involved in T1D as well as the relationship between the PD-1/ CTLA-4 genes and soluble CTLA-4 concentrations. Patients and methods 261 incident cases of T1D and 280 healthy children less 15 years old were included in this study. Haplotypes for polymorphisms of the PD-1 and CTLA-4 genes were determined by PCR and RFLP methods. Screening for soluble CTLA-4 was done using an ELISA assay. Statistical analysis was performed using the online SHESIS package. Results Our results show that sCTLA-4 levels were higher in T1D than in controls (2.99 ± 1.7 ng/ml versus 1.43 ± 0.31 ng/ml, p < 0.001). The allele dosage of CTLA-4 on PD-1 haplotypes, showing a significant modified effect of G carriers over AA genotype on the sCTLA-4 concentrations (5.48 ± 2.09 ng/ml versus 3.27 ± 1.30 ng/ml, p < 0.03 in T–C haplotype) and (1.92 ± 0.79 ng/ml versus 3.41 ± 1.10 ng/ml, p < 0.02 in C–T haplotype). Conclusion Consistent with the higher serum sCTLA-4 levels observed in other autoimmune diseases, our results suggest that sCTLA-4 is elevated in T1D. Our data suggest a possible gene dosage effect of “G” CTLA-4 carriers on sCTLA-4 over the possible protective or susceptible effect conferred by PD-1 haplotypes.

Association of Autoimmune Pancreatitis With Cytotoxic T-lymphocyte Antigen 4 Gene Polymorphisms in Japanese Patients

Autoimmune pancreatitis (AIP) is characterized by high serum IgG4 concentrations, lymphoplasmacytic inflammation, and a favorable response to corticosteroid treatment. Although the HLA DRB1*0405-DQB1*0401 haplotype and Fc receptor-like 3 polymorphisms have been associated with AIP, the role of other genetic factors is largely unknown. As cytotoxic T-lymphocyte antigen 4 (CTLA4) polymorphisms have recently been linked with several autoimmune diseases, we sought to determine if CTLA4 polymorphisms and serum sCTLA4 levels were associated with AIP as well. Five CTLA4 polymorphisms, located at -1722, -658, and -318 in the promoter, +49 in exon 1, and +6230 in the 3' untranslated region, were genotyped in 59 patients with AIP and 102 healthy subjects. Serum sCTLA4 levels were also determined in cohorts of 52 patients and 32 controls. Compared with healthy subjects, we found a significant increase in the +6230 G/G genotype (64%vs 42%, odds ratio [OR] 2.48, P= 0.011) in AIP patients. Haplotype 2, which had the +6230A, was associated with AIP resistance (OR 0.49, P= 0.011). The +49A/A and +6230A/A genotypes were associated with an enhanced risk of relapse (OR 5.45, P= 0.038 and OR 12.66, P= 0.022). Additionally, median serum sCTLA4 levels were significantly higher in patients with AIP (8.9 ng/mL) compared with healthy subjects (2.9 ng/mL, P < 0.001). The +6230 G/A polymorphism did not influence sCTLA4 levels in AIP patients. Our findings suggest that AIP is associated with a genetic polymorphism in CTLA4 and is positively correlated with serum sCTLA4 levels.

Lack of correlation between the levels of soluble cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) and the CT-60 genotypes

BackgroundCytotoxic T lymphocyte-associated antigen-4 (CTLA-4) plays a critical role in downregulation of antigen-activated immune response and polymorphisms at the CTLA-4 gene have been shown to be associated with several autoimmune diseases including type-1 diabetes (T1D). The etiological mutation was mapped to the CT60-A/G single nucleotide polymorphism (SNP) that is believed to control the processing and production of soluble CTLA-4 (sCTLA-4).MethodsWe therefore determined sCTLA-4 protein levels in the sera from 82 T1D patients and 19 autoantibody positive (AbP) subjects and 117 autoantibody negative (AbN) controls using ELISA. The CT-60 SNP was genotyped for these samples by using PCR and restriction enzyme digestion of a 268 bp DNA segment containing the SNP. Genotyping of CT-60 SNP was confirmed by dye terminating sequencing reaction.ResultsHigher levels of sCTLA-4 were observed in T1D (2.24 ng/ml) and AbP (mean = 2.17 ng/ml) subjects compared to AbN controls (mean = 1.69 ng/ml) with the differences between these subjects becoming significant with age (p = 0.02). However, we found no correlation between sCTLA-4 levels and the CTLA-4 CT-60 SNP genotypes.ConclusionConsistent with the higher serum sCTLA-4 levels observed in other autoimmune diseases, our results suggest that sCTLA-4 may be a risk factor for T1D. However, our results do not support the conclusion that the CT-60 SNP controls the expression of sCTLA-4.

Serum soluble CTLA-4 levels are increased in diffuse cutaneous systemic sclerosis.

To determine serum levels of soluble cytotoxic T-lymphocyte associated molecule-4 (sCTLA-4) and clinical association in patients with systemic sclerosis (SSc). Serum sCTLA-4 levels from 32 patients with diffuse cutaneous SSc (dSSc) and 27 patients with limited cutaneous SSc (lSSc) were examined by enzyme-linked immunosorbent assay (ELISA). For a longitudinal study, 211 sera from 30 SSc patients were analysed (follow-up 2.1-7.0 yr). Serum sCTLA-4 levels were elevated in dSSc patients compared with normal controls (n = 41), lSSc patients and patients with active systemic lupus erythematosus (SLE) (n = 23). By contrast, sCTLA-4 levels in patients with lSSc or SLE were normal. SSc patients with elevated sCTLA-4 levels had a shorter disease duration and more frequent presence of digital pitting scars, contracture of phalanges, diffuse pigmentation, pulmonary fibrosis and decreased percentage vital capacity (%VC) than those with normal sCTLA-4 levels. sCTLA-4 levels correlated positively with the extent of skin fibrosis, serum IgG levels and anti-topoisomerase I antibody levels. In a longitudinal study, sCTLA-4 levels decreased on a parallel with improvement of skin sclerosis in five dSSc patients. Skin sclerosis did not improve in two of six dSSc patients with high sCTLA-4 levels throughout the follow-up, while the remaining four patients showed improvement of skin sclerosis. These results suggest that sCTLA-4 correlates with disease severity and activity of SSc and that sCTLA-4 plays a role in immunological abnormalities of SSc, since sCTLA-4 may augment humoral immune responses as well as T-cell responses by interfering with B7-CTLA-4 interactions that induce negative signals in T and B cells.