IL-5 Promoter Polymorphism Enhances IgE Responses to Staphylococcal Superantigens in Adult Asthmatics

Interleukin 5 (IL-5) is a key cytokine involved in the induction of T-helper type 2 (Th2) responses in the asthmatic airway. We investigated IL-5 genetic polymorphisms associated with asthma phenotypes, including IgE responses to staphylococcal enterotoxins A and B (SEA and SEB, respectively), in asthmatics. Adult asthmatics (n=310) and normal controls (n=160) were enrolled in the present study. Serum total and specific IgE to SEA and SEB were measured. Two IL-5 polymorphisms, -746A>G and +4499T>G, were genotyped using the primer-extension method. There were no significant differences in genotype or haplotype frequencies of these polymorphisms between the two groups. Asthmatics carrying the AG/GG genotype at -746A>G had a significantly higher prevalence of serum specific IgE to SEA (P=0.008), higher total IgE levels (P=0.014), and lower PC20 methacholine levels (P=0.002) compared to those with the AA genotype. These findings suggest that the IL-5 promoter polymorphism at -746A>G enhances serum total and specific IgE responses to SEA, which may augment airway hyperresponsiveness in adult asthmatics.     

Association of PTPN22 polymorphsims and ankylosing spondylitis susceptibility

Background: As a susceptibility gene for AS, the polymorphsims of PTPN22 associated with disease susceptibility. Methods: We selected two SNPs of rs1217406 and rs1217414 within PTPN22 with Haploview software and investigated the relationship between the SNPs of PTPN22 gene and AS susceptibility. 120 AS patients and 100 healthy people were enrolled from Qilu Hospital of Shandong University. And we genotyped the SNPs of PTPN22 with PCR-RFLP method. Results: The results showed that C allele (rs1217406) and T allele (rs1217414) both were risk factors for AS (OR: 3.12, 2.13). The persons with A-T, C-C or C-T haplotypes were more likely to suffer AS (OR: 3.17, 3.66, 4.011). Conclusions: Due to the close relationship of PTPN22 and AS, the study may be helpful for the early diagnosis and differential diagnosis.     

PTPN22 Single-Nucleotide Polymorphisms in Iranian Patients with Type 1 Diabetes Mellitus

Background: PTPN22 plays a crucial role in regulating the function of various cells of the immune system, particularly T cells. Polymorphisms of the PTPN22 gene have been associated with many autoimmune diseases, including type 1 diabetes (T1D) which is a T-cell-mediated disease.

Objective: The present study was aimed at genotyping of an Iranian population for five polymorphisms of the PTPN22 gene.

Methods: The study population consisted of 99 T1D patients and 100 healthy controls. We genotyped five single-nucleotide polymorphisms (SNPs) (rs12760457, rs1310182, rs1217414, rs33996649, and rs2476601) of the PTPN22 gene.

Results: Regarding the variant rs2476601, genotypes AG and GG were increased and decreased in T1D patients compared with controls, respectively. Further, alleles G and A of this SNP were found to be decreased and increased in T1D patients, respectively (p value = 0.001). However, T1D and control groups did not differ on genotype distribution or allele frequency for other investigated SNPs.

Conclusions: The PTPN22 rs2476601 minor allele (A) was associated with T1D in Iran, accounting for its pathophysiology in autoimmune diseases.     

PTK2 and PTPN11 expression in myelodysplastic syndromes

OBJECTIVE:

The aim of this study was to evaluate the expression of protein tyrosine kinase 2 and protein tyrosine phosphatase non-receptor type 11, which respectively encode focal adhesion kinase protein and src homology 2 domain-containing protein-tyrosine phosphatase 2, in hematopoietic cells from patients with myelodysplastic syndromes.

METHODS:

Protein tyrosine kinase 2 and tyrosine phosphatase non-receptor type 11 expressions were analyzed by quantitative polymerase chain reaction in bone marrow cells from patients with myelodysplastic syndromes and healthy donors.

RESULTS:

Protein tyrosine kinase 2 and tyrosine phosphatase non-receptor type 11 expressions did not significantly differ between normal cells and myelodysplastic cells.

CONCLUSIONS:

Our data suggest that despite the relevance of focal adhesion kinase and src homology 2 domain-containing protein-tyrosine phosphatase 2 in hematopoietic disorders, their mRNA expression do not significantly differ between total bone marrow cells from patients with myelodysplastic syndromes and healthy donors.     

IgE and IgG Anti-Thyroid Autoantibodies in Chinese Patients With Chronic Spontaneous Urticaria and a Literature Review

Immunoglobulin (Ig) E and IgG anti-thyroid autoantibodies (AAbs) play important roles in the immunopathogenesis of chronic spontaneous urticaria (CSU). To date, association of IgE and IgG AAbs with Chinese CSU patients has not been fully investigated. We aimed to explore prevalence rates of IgE and IgG AAbs in Chinese CSU patients and their association with clinical and laboratory parameters. Serum IgE and IgG AAbs against thyroid peroxidase (TPO) and thyroglobulin (TG), total IgE (tIgE) and specific IgEs were measured using enzyme-linked immunosorbent assay, chemiluminescence microparticle immunoassay and immunoblotting. Meta-analyses and literature review were conducted. The meta-analyses indicated that CSU cases were 4.98, 6.90 and 6.68 times more likely to have positive anti-TPO IgE, anti-TPO IgG and anti-TG IgG (all P < 0.001) compared with controls, respectively, and revealed a positive correlation between the prevalence rates of anti-TPO IgE and anti-TPO IgG (r = 0.53, P = 0.025). A total of 1,100 Chinese Han adult CSU patients and 1,100 ethnicity-, age- and sex-matched healthy controls were recruited from 15 centers. Prevalence rates of anti-TPO IgE, anti-TPO IgG, anti-TG IgE or anti-TG IgG in the patients were all significantly higher than those in the controls. Significant correlations were observed between prevalence rates of anti-TPO IgE and anti-TPO IgG (r = 0.297, P < 0.001) as well as between those of anti-TG IgE and anti-TG IgG in the patients (r = 0.137, P < 0.001). Patients with anti-TPO IgE or anti-TPO IgG had significantly lower tIgE levels (P < 0.001). Positive anti-TPO IgE, positive anti-TPO IgG and tIgE < 40 IU/mL were independent predictors of antihistamine-refractory cases. In conclusion, the prevalence rates of IgE and IgG AAbs in Chinese CSU patients are significantly elevated and reciprocally correlated. This study verifies the results of previous case-control studies of CSU patients from other populations and ethnicities.     

Natural History and Influencing Factors of Chronic Urticaria in Children

PurposeChronic urticaria (CU) can reduce the quality of life of children and their parents, but there are only a few studies on the course of CU in children. This study aimed to investigate the natural course of CU in children and identify the factors that influence its prognosis.MethodsWe evaluated 77 children diagnosed with CU, who were monitored for at least 48 months. Subjects were classified as either chronic spontaneous urticaria (CSU) or other CU, and the clinical features were compared. Remission was defined as having no symptoms without treatment for more than 1 year. The remission rate was analyzed, and the factors influencing the prognosis were investigated.ResultsThe average age of the study population was 5.96 ± 4.06 years, and 64 (83.1%) patients had CSU. The remission rates at 6 months, 1 year, 2 years, 3 years, and 4 years after symptom onset were 22.1%, 40.3%, 52.0%, 63.7%, and 70.2%, respectively, for children with CU. For children with CSU, these values were 23.4%, 43.7%, 56.2%, 68.7%, and 75.0%, respectively. The total serum immunoglobulin E (IgE) levels were positively correlated with disease duration (r = 0.262, P = 0.021); no other factors were associated with the duration of the disease.ConclusionsA high proportion of children with CU were classified as CSU. No indicators, except for total IgE were found to predict the timing of spontaneous remission. The CU remission rate identified in this study is expected to be used as one of the reference data for the progress of CU in patients.     

Association Analysis Between FILIP1 Polymorphisms and Aspirin Hypersensitivity in Korean Asthmatics

Purpose

Aspirin exacerbated respiratory disease (AERD) results in a severe asthma attack after aspirin ingestion in asthmatics. The filamin A interacting protein 1 (FILIP1) may play a crucial role in AERD pathogenesis by mediating T cell activation and membrane rearrangement. We investigated the association of FILIP1 variations with AERD and the fall rate of forced expiratory volume in one second (FEV1).

Methods

A total of 34 common FILIP1 single nucleotide polymorphisms (SNPs) were genotyped in 592 Korean asthmatic subjects that included 163 AERD patients and 429 aspirin-tolerant asthma (ATA) controls.

Results

This study found that 5 SNPs (P=0.006-0.01) and 2 haplotypes (P=0.01-0.03) of FILIP1 showed nominal signals; however, corrections for the multiple testing revealed no significant associations with the development of AERD (P_corr>0.05). In addition, association analysis of the genetic variants with the fall rate of FEV1, an important diagnostic marker of AERD, revealed no significant evidence (P_corr>0.05).

Conclusions

Although further replications and functional evaluations are needed, our preliminary findings suggest that genetic variants of FILIP1 might be not associated with the onset of AERD.     

Cancer risk in patients with Noonan syndrome carrying a PTPN11 mutation

Noonan syndrome (NS) is characterized by short stature, facial dysmorphisms and congenital heart defects. PTPN11 mutations are the most common cause of NS. Patients with NS have a predisposition for leukemia and certain solid tumors. Data on the incidence of malignancies in NS are lacking. Our objective was to estimate the cancer risk and spectrum in patients with NS carrying a PTPN11 mutation. In addition, we have investigated whether specific PTPN11 mutations result in an increased malignancy risk. We have performed a cohort study among 297 Dutch NS patients with a PTPN11 mutation (mean age 18 years). The cancer histories were collected from the referral forms for DNA diagnostics, and by consulting the Dutch national registry of pathology and the Netherlands Cancer Registry. The reported frequencies of cancer among NS patients were compared with the expected frequencies using population-based incidence rates. In total, 12 patients with NS developed a malignancy, providing a cumulative risk for developing cancer of 23% (95% confidence interval (CI), 8-38%) up to age 55 years, which represents a 3.5-fold (95% CI, 2.0-5.9) increased risk compared with that in the general population. Hematological malignancies occurred most frequently. Two malignancies, not previously observed in NS, were found: a malignant mastocytosis and malignant epithelioid angiosarcoma. No correlation was found between specific PTPN11 mutations and cancer occurrence. In conclusion, this study provides first evidence of an increased risk of cancer in patients with NS and a PTPN11 mutation, compared with that in the general population. Our data do not warrant specific cancer surveillance.     

Association Between Serum IgE Levels and the CTLA4 +49A/G and FCER1B -654C/T Polymorphisms in Korean Children With Asthma

Purpose

T cells play a central role in cell-mediated immunity, atopic disease, and asthma. The balance of CD28/cytotoxic T-lymphocyte antigen 4 (CTLA4)-derived signal transduction plays an important role in the activation of T cells and an increased immunoglobulin E (IgE) response. The aim of the current study was to investigate the association between polymorphisms in the genes encoding both CTLA4 and the high-affinity IgE receptor 1B (FCER1B) and serum IgE levels in Korean children with asthma.

Methods

We enrolled 238 controls and 742 children with asthma. The CTLA4 +49A/G and FCER1B -654C/T polymorphisms were genotyped by PCR-restriction fragment length polymorphism analysis.

Results

We observed no difference in the distribution of CTLA4 +49A/G among controls, children with asthma, and those with atopic asthma. In contrast, the GA genotype of CTLA4 +49A/G in children with atopic asthma was significantly higher compared to that in those with non-atopic asthma. Moreover, significantly higher log Dp/Df-specific IgE levels were found in children with asthma and those with atopic asthma carrying one or two copies of the CTLA4 +49A versus those homozygous for +49G. Gene-gene interactions between CTLA4 and FCER1B with the heterozygote and homozygote of variant genotypes were associated with the log Dp/Df-specific IgE levels, but not asthma development. In addition, children with Dp/Df (+) asthma carried an elevated combined genotype of risk allele compared to those with Dp/Df (-) asthma.

Conclusions

The CTLA4 +49A/G polymorphism may contribute to the production of IgE in Korean children with asthma, especially in Dp/Df-specific IgE levels, but not in the direct development of asthma. In addition, Dp/Df-specific IgE levels with a FCER1B -654C/T polymorphism may involve additive effects.     

Elevated MRGPRX2 Levels Related to Disease Severity in Patients With Chronic Spontaneous Urticaria

Mas-related G-protein coupled receptor-X2 (MRGPRX2), a receptor on mast cells, basophils, and eosinophils associated with immunoglobulin E (IgE)-independent degranulation, has been reported to be highly expressed on cutaneous mast cells in patients with severe chronic spontaneous urticaria (CSU). We sought to investigate whether MRGPRX2 levels in the sera from CSU patients differ from those in healthy control subjects and to evaluate the clinical utility of MRGPRX2 levels in CSU patients. Severe CSU was defined as urticaria activity score over 7 days (UAS7) ≥ 28. Serum samples from 116 (73 severe and 43 non-severe) CSU patients and 50 healthy subjects were screened for MRGPRX2 using enzyme-linked immunosorbent assay. Serum MRGPRX2 levels were significantly higher in patients with severe CSU (median [interquartile range], 16.5 [10.8–24.8]) than in healthy controls (11.7 [6.5–21.2], P = 0.036) and in non-severe CSU patients (8.7 [4.5–18.8], P = 0.002), although they did not differ between healthy subjects and non-severe CSU patients. Serum MRGPRX2 levels in CSU patients showed positive correlations with UAS7 and specific IgE against Dermatophagoides farinae in CSU subjects, whereas no correlations were observed for age, sex, urticaria duration, atopy, combined angioedema, autologous serum skin test positivity, or total IgE levels. Logistic regression analysis identified serum MRGPRX2 ≥ 12 ng/mL (odds ratio, 6.421; P = 0.002) as an independent risk factor for severe CSU, along with increased serum total IgE levels, peripheral basophil percentage, and angioedema. In conclusion, we suggest that serum MRGPRX2 could help indicate severe CSU.     

Polymorphisms in TLR4 and TLR2 genes, cytokine production and survival in rural Ghana

Toll-like receptors (TLRs) are involved in the induction of an adequate immune response on infection. We hypothesized that genetic variation in TLR4 and TLR2 genes could influence this response and lead to variability in cytokine production and survival. We tested this hypothesis in 4292 participants who were followed up for all-cause mortality for 6 years and live under adverse environmental conditions in the Upper-East region of Ghana, where malaria is endemic. In 605 participants, tumor necrosis factor-α and interleukin-10 (IL10) production, after stimulation with lipopolysaccharide and zymosan, was measured. In addition, 34 single-nucleotide polymorphisms (SNPs) in TLR4 and 12 SNPs in TLR2 were genotyped and tested for association with cytokine production, malaria infection and mortality. In this comprehensive gene-wide approach, we identified novel SNPs in the TLR4 gene that influence cytokine production. From the analyzed SNPs, rs7860896 associated the strongest with IL10 production (P=0.0005). None of the SNPs in this study associated with malaria or overall mortality risks. In conclusion, we demonstrate that genetic variation within the TLR4 gene influences cytokine production capacity, but in an endemic area does not influence the susceptibility to malaria infection or mortality.     

The Association of GSDMB and ORMDL3 Gene Polymorphisms With Asthma: A Meta-Analysis

PurposeORM1-like 3 (ORMDL3) belongs to a highly conserved protein family which is anchored as transmembrane protein in the endoplasmic reticulum. Gasdermin B (GSDMB) is adjacent to ORMDL3 on chromosome 17q21.2 and belongs to the gasdermin-domain containing the protein family (GSDM family). Recent reports suggest that GSDMB and ORMDL3 are associated with asthma in several populations. However, genetic association studies that examined the association of GSDMB and ORMDL3 gene variants with asthma showed conflicting results. To assess whether combined evidence shows the association between GSDMB/ORMDL3 polymorphism and asthma.MethodsA bibliographic search from MEDLINE identified 13 original articles using the search keywords ''GSDMB'', ''ORMDL3'', and ''asthma''. An updated literature-based meta-analysis involving 6,691 subjects with asthma, 9,281 control individuals, and 1,360 families were conducted. Meta-odds ratios (ORs) and 95% confidence intervals (CIs) based on the fixed effects model or the random effects model depended on Cochran''s Q-statistic and I² values. Data from case-control and TDT studies were analyzed in an allelic model using the Catmap software.ResultsWe selected and identified 3 SNPs of ORMDL3 associated with asthma (rs8076131: OR=1.10; 95% CI, 1.02-1.20; P=0.012. rs12603332: OR=1.15; 95% CI, 1.05-1.25; P=0.002. rs3744246: OR=1.10; 95% CI, 1.02-1.17; P=0.008) and 1 SNP of GSDMB associated with asthma (rs7216389: OR=1.37; 95% CI, 1.27-1.47; P<0.01). Publication bias was estimated using modified Egger''s linear regression test proposed by Harbordetal and revealed no evidence of biases. Furthermore, cumulative meta-analysis in chronological order showed the inclination toward significant association for rs7216389 and rs12603332 with continually adding studies, and the inclination toward null-significant association for rs3744246 and rs8076131.ConclusionsModerate evidence exists for associations of the ORMDL3 rs8076131, rs12603332, and rs3744246 and GSDMB rs7216389 variants with asthma. Large sample size and representative population-based studies and TDT studies with homogeneous asthmatic patients and well-matched controls are warranted to confirm this finding.     

云南人群中PTPN22和PADI4基因多态性与类风湿关节炎的关联研究

目的 探讨云南人群PTPN22和PADI4基因的7个SNP多态与类风湿关节炎易感性的相关性.方法 选取192例类风湿关节炎患者和288名正常人进行病例对照研究.分别用PCR-RFLP法检测PTPN22基因的rs33996649和1858位点、PADI4基因的rs11203366和rs874881位点,用焦磷酸测序法检测PADI4基因的rs1635579、rs2428736和rs2240340共7个SNP位点的基因型.结果 在7个SNP位点中,PADI4基因的rs2240340位点的等位基因频率和基因型频率在病例组和对照组间差异有统计学意义(P＜0.05).结论 在云南人群中PADI4基因的rs2240340多态性与类风湿关节炎的易感性存在相关性.     

Association between EGFR polymorphisms and the risk of lung cancer

Target: The study aimed to investigate the role of epidermal growth factor receptor (EGFR) rs6965469 and rs763317 polymorphisms in the occurrence and development of lung cancer. Methods: We used polymerase chain reaction-ligation detection reaction (PCR-LDR) method to detect the genotypes of EGFR rs6965469 and rs763317 polymorphisms and the data were analyzed by GeneMapper software. Odds ratios (ORs) with 95% confidence intervals (CIs) was calculated by χ² test to estimate the significance difference of genotype and allele frequencies in case and control groups. ORs and 95% CIs were adjusted by logistic regression analysis with age, gender, drinking and smoking. The genotypes distributions of control group were tested by Hardy-Weinberg equilibrium (HWE). Results: The genotypes frequencies of controls for rs6965469 and rs763317 polymorphims were consistent with HWE. The distribution of rs6965469 TT genotype in two groups was significantly different (P<0.05) and TT genotype was associated with an increased risk of lung cancer (OR=6.92, 95% CI=1.33-36.00). AA genotype and A allele of rs763317 were also the susceptible factors of lung cancer. Individuals with AA genotype or A allele were more likely to suffer lung cancer (AA vs. GG: OR=7.20, 95% CI=1.33-39.07; A vs. G: OR=2.61, 95% CI=1.04-6.59). Conclusions: The EGFR rs6965469 and rs763317 polymorphisms may be risk factors for lung cancer.     

Association of abcb1 polymorphisms and ulcerative colitis susceptibility

Objective: Multi-drug resistance gene 1 (ABCB1) is closely related to bowel diseases. Therefore, our study was aimed to evaluate the correlation between ABCB1 polymorphisms (C1236T and C3435T) and ulcerative colitis (UC) susceptibility. Methods: A total of 61 UC patients and 64 healthy people participated in the study. Genotyping was conducted with the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). χ² test was used to evaluate the association of ABCB1 gene polymorphisms (C1236T and C3435T) and UC susceptibility. Results: For ABCB1 C1236T polymorphism, the frequencies of CC genotype and C allele were found higher in the cases than those in the controls (CC: 36.1% vs. 20.3%; C: 58.2% vs. 41.4%), which indicated that the CC genotype and C allele might increase the risk for UC (OR = 3.39, 95% CI = 1.28-8.97; OR = 1.97, 95% CI = 1.19-3.26). However, there were no statistical differences in the genotype or allele distribution of ABCB1 C3435T between the case and control group. Conclusion: The CC genotype and C allele of ABCB1 C1236T polymorphisms are significantly associated with UC susceptibility, so we conclude that ABCB1 C1236T polymorphisms might serve as genetic-susceptibility factors for UC. While, no remarkable relationship is observed between ABCB1 C3435T polymorphisms and UC.     

Association of Single Nucleotide Polymorphisms in the MD-2 Gene Promoter Region With Der p 2 Allergy

Purpose

Sensitization to house dust mite (Dermatophagoides pteronyssinus) is a considerable risk factor for the progression of allergic disease. The group 2 allergen from Dermatophagoides pteronyssinus, Der p 2, is considered a major one in patients with specific immunoglobulin E (IgE) to Der p 2. Der p 2 has structural homology with myeloid differentiation 2 (MD-2), which is involved in the lipopolysaccharide-binding component of the Toll-like receptor 4 signaling pathway and the development of inflammation. The aim of this study was to examine the genetic association of single nucleotide polymorphisms (SNPs) in the promoter region of MD-2 with Der p 2-sensitive allergy.

Methods

We investigated associations between cohort''s characteristics, including 280 allergic and 80 healthy subjects by examining total IgE, eosinophils, D. pteronyssinus-specific IgE, Der p 2-specific IgE, the number of IgE-producing B cells induced by Der p 2, and the odds ratio of allergic symptoms.

Results

Based on the 1,000 genome project data, the minor allele frequencies of the rs1809441 and rs1809442 are 0.467 and 0.474, respectively. However, the correlation of linkage disequilibrium (LD) between these 2 SNPs is D''=1, the genotype frequencies of the 2 MD-2 (LY96) SNPs (rs1809441 and rs1809442) that are located nearby were significantly different between allergic and health subjects: the TT genotype of rs1809441 and the GG genotype of rs1809442 were more frequent in allergic subjects than in healthy subjects (16.1% vs 2.5% in both genotypes). The allergic patients with these genotypes exhibited significantly higher levels of D. pteronyssinus-specific IgE and Der p 2-specific Ig E, and a larger number of Der p 2-activated B cells. In addition, these 2 SNPs in the MD-2 promoter region were significantly associated with the prevalence of nasal, skin, and asthmatic allergic symptoms.

Conclusions

Our results indicated that 2 SNPs in the MD-2 promoter region were significantly associated with Der p 2-specific Ig E, and thereby suggest that these SNPs may play a major role in susceptibility to Der p 2-triggered immune responses in a Taiwanese population.     

Polymorphisms of <Emphasis Type="Italic">PTPN11</Emphasis> Coding SHP-2 as Biomarkers for Ulcerative Colitis Susceptibility in the Japanese Population

Objective  To identify genetic determinants of inflammatory bowel disease (IBD), we examined an association between polymorphisms of both the programmed cell death 1 gene (PDCD1) and the src homology 2 domain-containing tyrosine phosphatase 2 gene (PTPN11) and susceptibility to IBD. Methods  Study subjects comprised 114 patients with ulcerative colitis (UC), 83 patients with Crohn’s disease, and 200 healthy control subjects. Five single nucleotide polymorphisms (SNPs) in PDCD1 and PTPN11 were detected by polymerase chain reaction restriction fragment length polymorphism. Subsequently, haplotypes composed of the two SNPs in PTPN11 were constructed. Results  The frequencies of the Hap 1 haplotype and its homozygous Hap 1/Hap 1 diplotype of PTPN11 were significantly increased in UC patients compared to control subjects (P = 0.011 and P = 0.030, respectively). While no association was found for PDCD1 for UC or CD and none for PTPN11 for CD. Conclusion   PTPN11 is a genetic determinant for the pathogenesis of UC, and haplotyping of PTPN11 may be useful as a genetic biomarker to identify high-risk individuals susceptible to UC.     

Immune Aberrations in B and T Lymphocytes Derived from Chronic Urticaria Patients

To investigate the pathophysiology of chronic urticaria (CU) in light of the abundant evidences that it is an autoimmune disease and to define some cellular markers in B/T lymphocytes that could be of pathogenic significance, we investigated 14 patients suffering from CU, compared to 7 contact dermatitis patients and 10 normal control individuals. We tested the expression of CD5, B7.1 (CD₈₀), CD₂₃, and CD₂₅ on B cells and of CD_40L and CD₂₅ on T cells from all studied individuals. We also tested B cell proliferation upon their activation followed by dexa-methazone induced inhibition of proliferation. The expression of bcl-2 protein in activated lymphocytes from normal individuals was compared to that of contact dermatitis and CU patients. CD_40L expression was found significantly higher on in vitro activated CD₃ [with phorbol myristate acetate (PMA) and ionomycine Ca²⁺ at 12 hr of culture] from CU patients compared to that of contact dermatitis and normal individuals. Whereas the proliferation of activated B cells from CU patients was higher, dexamethazone-induced inhibition of B cell proliferation was found statistically similar in both groups yet lower in B cells from most severe CU patients. We demonstrate a higher bcl-2 expression in activated B and T lymphocytes of severe CU patients compared to that of moderate CU and both contact dermatitis and normal individuals. The increased expression of CD_40L on activated T cells might play a role in the polyclonal increased B cell proliferation of CU patients. This increased proliferation accompanies the finding that activated B and T lymphocytes from these patients demonstrate increased bcl-2 expression. The resistance of some B cells to dexamethazone-induced inhibition of proliferation encourages us to investigate the possibility that B cells from some CU patients might develop rescue mechanisms from activated cell death. These findings provide further evidence that CU is indeed an autoimmune disease, although its precise nature has yet to be fully elucidated.     

Polymorphisms in the P2X7 receptor gene are associated with low lumbar spine bone mineral density and accelerated bone loss in post-menopausal women

The P2X7 receptor gene (P2RX7) is highly polymorphic with five previously described loss-of-function (LOF) single-nucleotide polymorphisms (SNP; c.151+1G>T, c.946G>A, c.1096C>G, c.1513A>C and c.1729T>A) and one gain-of-function SNP (c.489C>T). The purpose of this study was to determine whether the functional P2RX7 SNPs are associated with lumbar spine (LS) bone mineral density (BMD), a key determinant of vertebral fracture risk, in post-menopausal women. We genotyped 506 post-menopausal women from the Aberdeen Prospective Osteoporosis Screening Study (APOSS) for the above SNPs. Lumbar spine BMD was measured at baseline and at 6-7 year follow-up. P2RX7 genotyping was performed by homogeneous mass extension. We found association of c.946A (p.Arg307Gln) with lower LS-BMD at baseline (P=0.004, β=-0.12) and follow-up (P=0.002, β=-0.13). Further analysis showed that a combined group of subjects who had LOF SNPs (n=48) had nearly ninefold greater annualised percent change in LS-BMD than subjects who were wild type at the six SNP positions (n=84; rate of loss=-0.94%/year and -0.11%/year, respectively, P=0.0005, unpaired t-test). This is the first report that describes association of the c.946A (p.Arg307Gln) LOF SNP with low LS-BMD, and that other LOF SNPs, which result in reduced or no function of the P2X7 receptor, may contribute to accelerated bone loss. Certain polymorphic variants of P2RX7 may identify women at greater risk of developing osteoporosis.