强直性脊柱炎患者血液HLA-B27的临床参考值的预测

目的 以实时荧光定量PCR（FQ-PCR）检测可疑患者HLA-B27的定量水平,研究强直性脊柱炎（AS）与HLA-B27的相关性,明确HLA-B27的检测值范围并用于AS的确诊诊断.方法 针对本院2005年~2010年收集的168例骶髂关节及下腰部疼痛等症状疑似AS病例进行回顾性分析,获得所有病例外周静脉血标本,然后通过实时荧光定量PCR进行HLA-B27的定量检测,疑似病例分为AS患者、HLA-B27阳性的非AS患者、HLA-B27阴性的非AS患者三组,根据临床体征、影像学进行确诊病情,同时选取健康体检者52例外周静脉血标本的HLA B-27测定结果进行对照,统计分析各变量与AS存在之间的关系.结果 AS患者、HLA-B27阳性的非AS患者、HLA-B27阴性的非AS患者、健康体检者的HLA-B27循环阈值（ct）平均值分别为：26.3 copies/ml、17.5 copies/ml、6.2 copies/ml、4.9 copies/ml,单变量分析表明,HLA-B27与化脓性关节炎明显相关（P＜0.05）.结论 AS患者HLA-B27定量分析循环阈值（ct）的95%参考值范围为（17.3~35.3）copies/ml,HLA-B27定量分析可作为疾病发病的参照影响因素及预测因素.     

Toll-like receptor (TLR)2 and TLR3 synergy and cross-inhibition in murine myeloid dendritic cells

Toll-like receptors (TLRs) play an important role in the innate recognition of pathogens by dendritic cells (DCs) and in the induction of immune responses. Few studies have been devoted to address the impact of TLR2 (a fully MyD88-dependent receptor) and TLR3 (a fully TRIF-dependent receptor) co-activation on DC functions, especially in the mouse system. Using canonical agonists, we show that TLR2 acts in concert with TLR3 to induce the synthesis of inflammatory cytokines (TNF-alpha, IL-6), of some IL-12 family members (IL-12p40, IL-12p23, IL-27p28) and of the Notch ligand Delta-4 by mouse DCs. In contrast, TLR2 interferes with the TLR3-induced expression of type I interferon stimulated genes (MIG/CXCL9, IP-10/CXCL10, GARG39) and IL-12p35. We also report that TLR2 cooperates with TLR3 to enhance the DC-mediated production of IFN-gamma by Natural Killer cells and by conventional Ag-specific T lymphocytes. To conclude, our data support the existence of TLR2 and TLR3 synergy and cross-inhibition in DCs that could be important to strengthen immune responses during infection.     

Differential cytokine and Toll-like receptor expression in leukemia

Toll-like receptors (TLRs) and cytokines function in immune regulation and thus may be dysregulated in disease. In this study, 25 leukemia cases and 10 normal controls were analyzed by flow cytometry for differential cytokine and TLR expression. The percentages of CD3+ cells producing TNF-alpha, IL-2, IL-3, IL-4, IL-6, IL-10, IL-12, and IFN-gamma were determined. Statistically significant differences between lymphocytic leukemia cases and normals were observed for all cytokines except IL-12. Differences in expression of all cytokines other than IL-6 and IFN-gamma proved to be statistically significant between myeloid leukemic and normal cases. IFN-gamma and IL-3 dual staining was observed to be most prominent in leukemic samples. Additionally, the staining intensities of TLR3, TLR4, TLR8, and TLR9 in regard to CD3+ cells were evaluated and compared among the three groups. The increased staining intensity of TLR9 in leukemic cases compared to levels in normal controls was statistically significant. No differences of statistical significance were observed between the two leukemic groups for cytokine or TLR expression. These results warrant further study of the mechanism and potential therapeutic value targeting these leukemic patterns.     

Associations between toll-like receptors and interleukin-4 in the lungs of patients with tuberculosis

Toll-like receptors (TLRs) are implicated in the intracellular killing of Mycobacterium tuberculosis, and their expression is modulated by interleukin-4 (IL-4) in vitro. Our aim was to examine the expression of TLRs at the site of pathology in tuberculous lung granulomas and to explore the effect of the immune response on TLR expression. Immunohistochemistry was performed on lung granulomas from nine patients with tuberculosis undergoing lobectomy for haemoptysis. All nine patients expressed all of the TLRs studied (TLRs 1-5 and 9), whereas only five out of the nine patients had any granulomas positive for IL-4. Statistical analysis of TLR and cytokine staining patterns in 183 individual granulomas from the nine patients revealed significant associations between pairs of receptors and IL-4. A positive association between TLR2 and TLR4 (P < 0.0001) and a negative association between TLR2 and IL-4 (P < 0.0001) was observed. The associations between TLRs 1, 5, and 9 were significantly different in IL-4-negative compared with IL-4-positive patients. In conclusion, TLRs are expressed by various cell types in the human tuberculous lung, and their expression patterns are reflected by differences in the immune response.     

Toll-like receptor signaling is impaired in dendritic cells from patients with X-linked agammaglobulinemia

Bruton's tyrosine kinase (BTK), which is defective in patients with X-linked agammaglobulinemia (XLA), is expressed not only in B cells but also in monocytes and dendritic cells (DCs). DCs play a crucial role in the innate immune response against infections by sensing pathogens through Toll-like receptors (TLRs). However, it is not known whether BTK deficiency in XLA might impair TLR-mediated signaling in DCs, which are susceptible to various infections. The phenotypic maturation and cytokine production mediated by TLRs were examined in monocyte-derived DC from XLA patients and normal controls. The TLR expression in DCs was analyzed by flow cytometry. TLR-mediated signaling in DCs was evaluated for the phenotypic maturation based on CD83 expression and production of cytokines, such as TNF-alpha, IL-6 and IL-12p70. TLR levels in DCs were similar between XLA and controls. TLR2, TLR4 and TLR7/8 ligands elicited less phenotypic maturation of DCs from XLA patients than normal controls based on CD83 expression. Stimulation with TLR2, TLR4 and TLR7/8 ligands, as well as TLR3 ligand, resulted in significantly lower production of TNF-alpha, but neither IL-6 nor IL-12p70, by DCs from XLA patients in comparison to normal controls. These findings suggest that BTK may thus be required for TLR signaling in DCs. The impaired TLR signaling in DCs may therefore be partly responsible for the occurrence of severe infections with bacteria and some viruses in XLA patients.     

Impaired cytokine response in myeloid dendritic cells in chronic hepatitis C virus infection regardless of enhanced expression of Toll-like receptors and retinoic acid inducible gene-I

Dendritic cells utilize various sets of Toll-like receptors (TLR) or cytosolic sensors to detect pathogens and evoke immune responses. In patients with hepatitis C virus (HCV) infection, a higher prevalence of various infectious diseases is reported; suggesting that innate immunity against pathogens is impaired. The aim of this study was to clarify whether the TLR and retinoic acid inducible gene-I (RIG-I) system in myeloid dendritic cells is preserved or not in chronic HCV infection. The expression of TLRs, RIG-I and its relatives were compared in myeloid dendritic cells between 39 patients and 52 healthy volunteers. The induction of type-I interferon (IFN) and inflammatory cytokines was examined in response to agonists for TLR2 (palmitoyl-3-cysteine-serine-lysine-4), TLR3/RIG-I (polyinosine-polycytidylic acid) or TLR4 (lipopolysaccharide). The relative expressions of TLR2, TLR4, RIG-I, and LGP2 from the patients were significantly higher than those from the volunteers, whereas TLR3 and MDA-5 expressions did not differ. In search for factors regulating TLR/RIG-I expression, it was shown that IFN-alpha, polyinosine-polycytidylic acid and lipopolysaccharide induced TLR3, TLR4 and RIG-I, but TNF-alpha, HCV core or HCV non-structural proteins did not. For the functional analyses, myeloid dendritic cells from the patients induced significantly less amounts of IFN-beta, TNF-alpha and IL-12p70 in response to polyinosine-polycytidylic acid or lipopolysaccharide. It is noteworthy that the expression of TRIF and TRAF6, which are essential adaptor molecules transmitting TLR3 or TLR4-dependent signals, is reduced in the patients. Thus, innate cytokine responses in myeloid dendritic cells are impaired regardless of enhanced expressions of TLR2, TLR4, and RIG-I in HCV infection.     

Critical involvement of pneumolysin in production of interleukin-1alpha and caspase-1-dependent cytokines in infection with Streptococcus pneumoniae in vitro: a novel function of pneumolysin in caspase-1 activation

Pneumolysin is a pore-forming cytolysin known as a major virulence determinant of Streptococcus pneumoniae. This protein toxin has also been shown to activate the Toll-like receptor 4 (TLR4) signaling pathway. In this study, a mutant S. pneumoniae strain deficient in pneumolysin (Deltaply) and a recombinant pneumolysin protein (rPLY) were constructed. Upon infection of macrophages in vitro, the ability to induce the production of interleukin-1alpha (IL-1alpha), IL-1beta, and IL-18 was severely impaired in the Deltaply mutant, whereas there was no marked difference in the induction of tumor necrosis factor alpha (TNF-alpha) and IL-12p40 between the wild type and the Deltaply mutant of S. pneumoniae. When macrophages were stimulated with rPLY, the production of IL-1alpha, IL-1beta, and IL-18 was strongly induced in a TLR4-dependent manner, whereas lipopolysaccharide, a canonical TLR4 agonist, hardly induced these cytokines. In contrast, lipopolysaccharide was more potent than rPLY in inducing the production of TNF-alpha, IL-6, and IL-12p40, the cytokines requiring no caspase activation. Activation of caspase-1 was observed in macrophages stimulated with rPLY but not in those stimulated with lipopolysaccharide, and the level of activation was higher in macrophages infected with wild-type S. pneumoniae than in those infected with the Deltaply mutant. These results clearly indicate that pneumolysin plays a key role in the host response to S. pneumoniae, particularly in the induction of caspase-1-dependent cytokines.     

HLA-A*9, a probable secondary susceptibility marker to ankylosing spondylitis in Basque patients

HLA-B27 is strongly associated to ankylosing spondylitis (AS). The objective of our study was to analyze HLA-B27 association, B27 subtype distribution and frequency of other HLA class I and DR antigens in a group of Basque AS patients. HLA class I antigens were typed serologically and HLA-B27 and A9 subtypes were determined by DNA typing in samples from 46 patients with AS, 54 B27-positive spondyloarthropathies, 82 healthy subjects and 20 B27-positive controls. A class I HLA 9.2 kb PvuII restriction fragment length polymorphism (RFLP), previously associated with AS, was analyzed in a representative group of patients and controls. We found that HLA-B*2705 conferred a relative risk of 126 for AS in this group. HLA-A9 (A*2402) allele was significantly increased in AS patients compared with healthy controls and B27-positive control group (Pcorr<0.0001) and also increased in patients affected with peripheral arthritis. No association between class I HLA 9.2 Kb RFLP and AS was found. These results suggest that HLA-A*9 allele itself or another linked gene could act as a secondary and independent susceptibility allele to AS.     

Toll-like receptors TLR2 and TLR4 initiate the innate immune response of the renal tubular epithelium to bacterial products

Renal tubular epithelial cells (TECs) respond diffusely to local infection, with the release of multiple cytokines, chemokines and other factors that are thought to orchestrate the cellular constituents of the innate immune response. We have investigated whether the Toll-like receptors TLR4 and TLR2, which are present on tubular epithelium and potentially detect a range of bacterial components, co-ordinate this inflammatory response acting through nuclear factor-kappa B (NF-kappaB). Primary cultures of TECs were grown from C57BL/6, C3H/HeN, C3H/HeJ, TLR2 and TLR4 knock-out mice. Cell monolayers were stimulated with lipopolysaccharide (LPS) and synthetic TLR2 and 4 agonists. The innate immune response was quantified by measurement of the cytokines tumour necrosis factor (TNF)-alpha and KC (IL-8 homologue) in cell supernatants by enzyme-linked immunosorbent assay. Cultured TECs grown from healthy mice produced the cytokines TNF-alpha and KC in response to stimulation by LPS and synthetic TLR2 and TLR4 agonists. Cells lacking the respective TLRs had a reduced response to stimulation. The TLR2- and TLR4-mediated response to stimulation was dependent on NF-kappaB signalling, as shown by curcumin pretreatment of TECs. Finally, apical stimulation of these TLRs elicited basal surface secretion of TNF-alpha and KC (as well as the reverse), consistent with the biological response in vivo. Our data highlight the potential importance of TLR-dependent mechanisms co-ordinating the innate immune response to upper urinary tract infection.     

Possible role of enteric organisms in the pathogenesis of ankylosing spondylitis and other seronegative arthropathies.

One-hundred eighty-five clinical isolates of Salmonella sp., Shigella sp., Escherichia coli, and Campylobacter sp. were tested for their ability to absorb the lymphocytotoxic activity of an antiserum (anti-Klebsiella sp. K43) directed against a specific HLA-B27-associated cell surface determinant on the lymphocytes of patients with ankylosing spondylitis (AS). Seven of these isolates (three Salmonella sp., two Shigella sp., one E. coli, and one Campylobacter sp.) were found to cross-react with the B27-positive cells of AS patients (B27+ AS+); an E. coli organism isolated from the rectal swab of an HLA-B27-negative clinically normal individual also cross-reacted with B27+ AS+ cells. These cross-reactive enteric organisms elaborate a factor (modifying factor) which specifically modifies the B27-positive lymphocytes of normal individuals; this factor is structurally and antigenically related to a functionally similar factor secreted by certain isolates of Klebsiella sp. These data suggest that certain enteric organisms share a common determinant which cross-reacts with B27+ AS+ cells. It is suggested that this cross-reactivity is somehow related to an early event in the pathogenesis of AS and possibly of other seronegative arthropathies.     

Toll-like receptors, cytokines and HIV-1

The present investigation examined variations in cytokine and Toll-like receptor expression by T-lymphocytes in HIV infection. 50 HIV cases and 10 normal controls were evaluated for TLR3, TLR4, TLR8, TLR9, IL-2, IL-4, IL-6, IL-10, IL-12, TNF-alpha, and IFN-gamma expression and staining intensities. TLR3 was expressed in 37 HIV (74%) cases, and TLR4 was brightly expressed in all (100%) HIV cases. However, TLR3 and TLR4 remained negative in all normal controls. Results reveal that TLR4 up-regulation is not limited to gram-negative bacterial infection. No statistical difference was detected when TLR8 and TLR9 expression were compared between the two test populations. A statistically significant difference was detected when IL-2, IL-4, IL-6, IL-10, IL-12, and IFN-gamma expression were analyzed in HIV cases and normal controls. When cytokine expression was compared with stage of disease, results indicated that a Th(1) to Th(2) cytokine switch did not occur. Only TNF-alpha expression decreased as infection progressed from the chronic phase into AIDS. When TLR expression was compared to cytokine expression, no statistical differences were detected. These data point to the need for a more in-depth study to determine whether or not the up-regulation of Toll-like receptor expression increases cytokine expression via the NFkappaB pathway.     

Toll-like receptor stimulation induces higher TNF-alpha secretion in peripheral blood mononuclear cells from patients with hyper IgE syndrome

Hyper IgE syndromes (HIES) are primary immunodeficiency disorders of unknown pathogenesis. Patients are typically affected with 'cold' abscesses of the skin, recurrent cyst-forming pneumonia, chronic mucocutaneous candidiasis and other less frequent features such as progressive skeletal abnormalities. Defective signaling in the Toll-like receptor (TLR) pathways has been suggested as a responsible pathologic mechanism, however, in previous reports, 10 patients revealed no defect in inflammatory cytokine responses to different TLR ligands. Here, we report the increase in pro-inflammatory cytokines TNF-alpha and IL-8, following TLR2 and TLR4 stimulation in a larger cohort of 25 additional patients with HIES, and provide a meta-analysis of the TLR data in HIES.     

HLA-B27 alone rather than B27-related class I haplotypes contributes to ankylosing spondylitis susceptibility

Characterization of non-B27 susceptibility genes will be required to know the pathogenesis of AS. The aim of this study was to examine whether ankylosing spondylitis (AS) susceptibility is controlled by B27 alone rather than B27 haplotypes and, whether other closely related class I loci, such as MICA and TNFA genes might play a role in AS. Three hundred eleven B27-positive samples from Caucasoid, Asian, and African populations were selected and genotypes were carried out by PCR/SSOP (HLA-B27 and HLA-C), PCR/SSP (MICA-TM polymorphism in the transmembrane region), PCR/SSCP (MICA alleles), and PCR-RFLP (TNF-alpha). Of these, 161 were AS patients, chosen in order to investigate the contribution of TNFA and MICA loci to AS in HLA-B27 positive individuals. Some findings can be concluded from the study: (a) No significant differences of TNF-alpha promoter alleles at position -308 and -238 (A/G) were found between AS patients and B27 matched alleles from healthy controls; (b) strong linkage disequilibrium was found between the B27 and the MICA alleles. The MICA-A4 was found to be in association with B*2705,02,03 and 08; MICA-A5 with B*2704 and B*2707 and MICA-A.5.1 with B*2706; (c) no significant differences of MICA alleles were found between AS and controls carrying the B27-associated alleles, and therefore no evidence is provided for an additional role of MICA gene in AS susceptibility; (d) there are a striking correlations between the structure of B27 extended haplotypes (from MICA region to HLA-C) and the ethnic distribution of these subtypes. The results of differential linkage disequilibrium with HLA-B27 subtypes suggest that B27 itself remains the primary gene for AS susceptibility, and TNFA and MICA are not involved in the pathogenesis of the disease.     

外周血T淋巴细胞HLA-B27检测辅助诊断强直性脊柱炎

目的 探讨外周血T淋巴细胞HLA-B27和血清多项免疫指标检测对强直性脊梓炎(AS)的辅助诊断价值.方法 采用流式细胞仪对52例疑似AS患者外周血T淋巴细胞HLA-B27表达进行检测,结合临床资料对AS作出诊断;对其中37例男性病例血清免疫球蛋白IgG、IgA、IgM,补体C3、C4及C反应蛋白(CRP)含量进行免疫比浊法测定.结果 52例疑似AS患者共检测出 HLA-B27+13例(男性12例,女性1例),确诊AS患者12人(男性患者11人,女性1人),包括男性HLA-B27+AS患者9例(最小年龄12岁,最大58岁),男性HLA-B27-AS 2例(分别为20岁和78岁),女性HLA-B27-AS 1例为(9岁),男性AS确诊患者的HLA-B27阳性率为82%.除补体C3外,男性AS组IgG、IgA、IgM、C4及CRP均较男性非AS组高(P＜0.05).结论 AS患者体液免疫功能明显活跃,HLA-B27检测有助于临床资料疑似病例的AS诊断.     

MICA gene and ankylosing spondylitis: linkage analysis via a transmembrane-encoded triplet repeat polymorphism

In order to address the possibility that the MICA gene located 47 kb upstream from HLA-B is involved in the pathogenesis of ankylosing spondylitis (AS), we have investigated microsatellite polymorphism in the transmembrane region of MICA in Caucasian patients with AS. The microsatellite allele consisting of 4 repetitions of GCT/AGC was present at significantly higher frequency in the patient group (Pc<0.0000001) than in the ethnically matched control group. However, the frequency of the (GCT/AGC)₄ allele was significantly low in the B27-positive patients than in the B27-positive healthy controls (Pc=0.0145). These observations suggest that B27 itself remains the primary genetic marker for AS, although the significantly dissimilar pheno-type frequency of the (GCT/AGC)₄ allele in B27-positive patients and healthy individuals may reflect the existence of other genetic factor(s) in the HLA-B27 haplotype involved in the development of AS.     

MyD88 and TLR2, but not TLR4, are required for host defense against Cryptococcus neoformans

We investigated here the potential role of Toll-like receptors (TLR) and the adaptor protein MyD88 in innate immunity responses to Cryptococcus neoformans, a pathogenic encapsulated yeast. Peritoneal macrophages from MyD88(-/-) or TLR2(-/-) mice released significantly less TNF-alpha, compared with wild-type controls, after in vitro stimulation with whole yeasts. In contrast, no differences in TNF-alpha release were noted between macrophages from C3H/HeJ mice, which have a loss of function mutation in TLR4, relative to C3H/HeN controls. When MyD88- or TLR2-deficient mice were infected with low doses of the H99 serotype A strain, all of the control animals, but none of MyD88(-/-) and only 38% of the TLR2(-/-) animals survived, in association with higher fungal burden in the mutant mice. Both MyD88(-/-) and TLR2(-/-) animals showed decreased TNF-alpha, IL-12p40 and/or IFN-gamma expression in various organs during infection. No difference in susceptibility to experimental cryptococcosis was found between C3H/HeJ mice and C3H/HeN controls. In conclusion, our data indicate that TLR2 and MyD88, but not TLR4, critically contribute to anti-cryptococcal defenses through the induction of increased TNF-alpha, IL-12 and IFN-gamma expression.     

TAP polymorphism is not associated with ankylosing spondylitis and complications with acute anterior uveitis in HLA-B27-positive Japanese

Abstract: HLA-B27 is associated with the etiology of ankylosing spondylitis (AS) and acute anterior uveitis (AAU). Transporter associated with antigen processing (TAP) 1 and TAP2 polymorphism influences the range of peptide presented by HLA class I molecules. In this report, contribution of TAP polymorphism to the susceptibility to AS and AAU was studied in HLA-B27-positive Japanese individuals. Patients were classified into three groups: 16 AS patients, 14 AAU patients and 22 patients with both AS and AAU. Twelve HLA-B27-positive healthy individuals were included as a control. TAP polymorphism was detected by PCR-RFLP methods. Significant differences in frequencies of TAP1 alleles were not found between patient groups. None of the TAP2 frequencies showed increased or decreased frequencies compared with HLA-B27-positive healthy controls. In comparison with a random Japanese control, TAP2D allele frequency was significantly increased in the AAU group, but failed to reach a significant level in a group consisting of the AAU-only patients and the patients with both AS and AAU. All of the patient groups were noted to have a significantly increased prevalence of the TAP2H allele as compared to random controls; however, the higher frequency of this allele was detected in HLA-B27 healthy controls as well. These observations suggest a linkage disequilibrium between TAP2D, TAP2H and HLA-B27 in Japanese.     

Phenotype Difference between Familial and Sporadic Ankylosing Spondylitis in Korean Patients

Clustered occurrences of ankylosing spondylitis (AS) in family have been noticed. We evaluated patients with AS confirmed by the modified New York criteria for familial history of AS (one or more first to third degree relatives). The clinical characteristics and the recurrence risks (number of AS patients/number of familial members) of the familial AS compared to sporadic AS were investigated. Out of a total of 204 AS patients, 38 patients (18.6%) reported that they had a familial history of AS. The recurrence risks in the familial AS patients for first, second and third degree family members were 14.5%, 5.2%, and 4.4% respectively. Erythrocyte sedimentation rate (ESR) (22.6±22.2 vs 35.4±34.4, P=0.029) and C-reactive protein (CRP) (1.24±1.7 vs 2.43±3.3, P=0.003) at diagnosis, body mass index (21.9±2.7 vs 23.7±3.3, P=0.002) and frequency of oligoarthritis (13.2% vs 33.7%, P=0.021) were significantly lower in the familial form. The presence of HLA-B27 (97.4% vs 83.1%, P=0.044) was significantly higher in familial AS. In conclusion, Korean familial AS patients show a lower frequency of oligoarthritis, lower BMI, lower ESR and CRP at diagnosis and higher presence of HLA-B27.

Graphical Abstract

相似文献   

Expression of Toll-like receptors and their association with cytokine responses in peripheral blood mononuclear cells of children with acute rotavirus diarrhoea

To understand virus and host interactions and host responses to rotavirus infection in children, we analysed by real-time polymerase chain reaction (PCR) the expression of mRNA for five Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR7 and TLR8) and four T helper (Th)1 and Th2 cytokines [interleukin (IL)-2, IL-12, interferon (IFN)-gamma and IL-4) in peripheral blood mononuclear cells (PBMC) of children with acute rotavirus diarrhoea. We observed significantly higher expression of genes encoding TLR2, TLR3, TLR4, TLR7 and TLR8 in PBMC of 41% (31/75) patients within 3 days of illness onset than those in healthy children. After 3 days of illness onset, only TLR3 and TLR8 mRNA expressions were still significantly (P<0.05) increased in 59% (44/75) children with diarrhoea. We also observed significantly (P<0.05) elevated expression of IL-12p40 and IFN-gamma in PBMC of patients during the entire period of illness and the first 3 days of illness, respectively. We further demonstrated a weak but significant association between elevated levels of gene expression of four TLRs (TLR2, TLR3, TLR4 and TLR8) and IFN-gamma. Our results suggest that multiple TLRs may modulate the immune response in the acute phase of rotavirus infection and play a role in the activation of IFN-gamma.     

Association of CYP17 with HLA-B27-negative seronegative spondyloarthropathy in Japanese males

Susceptibility genes for seronegative spondyloarthropathy (SNSA) other than HLA-B27 remain unclarified. Sex hormones are implicated in the pathogenesis of SNSA. Cytochrome P450c17a (CYP17) is a key regulator of androgen biosynthesis, and a single nucleotide polymorphism (SNP) in the 5'-untranslated region of the CYP17 gene (CYP17), -34C > T, is associated with variety of diseases. We have investigated the association between the CYP17 SNP and SNSA in Japanese males. Genomic DNA was extracted from 149 Japanese male SNSA patients and 380 controls. The CYP17 SNP was genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis. Allelic and genotypic frequencies of the SNP were compared between SNSA patients and controls, and within SNSA patients. We also computed haplotype frequencies using an expectation-maximization algorithm, analyzed the difference between SNSA and control groups, and examined the potential association of other known SNPs in the CYP17 gene. The frequency of the -34T allele was significantly increased in HLA-B27-negative SNSA, but not in total or HLA-B27-positive SNSA when compared to controls. The T allele was more prevalent in HLA-B27-negative SNSA than in HLA-B27-positive SNSA, and the T/T genotype was over-represented in HLA-B27-negative SNSA. Haplotype analysis did not demonstrate more significant association. The CYP17 SNP is associated with SNSA in HLA-B27-negative Japanese males.