Polymorphisms in the B-type natriuretic peptide (BNP) gene are associated with NT-proBNP levels but not with diabetic nephropathy or mortality in type 1 diabetic patients.

BACKGROUND: Circulating N-terminal pro-brain natriuretic peptide (NT-proBNP) levels are elevated in patients with diabetic nephropathy and independently predict excess cardiovascular morbidity and mortality. Therefore, we investigated the association between two polymorphisms -381T/C and 1551G/A of the BNP gene, plasma NT-proBNP levels and mortality prognosis in 380 type 1 diabetic patients with and without diabetic nephropathy. METHODS: In a prospective observational follow-up study, 197 type 1 diabetic patients with diabetic nephropathy {121 men, age [mean (SD)] 41 +/- 9.5 years, duration of diabetes 28 +/- 8.0 years, glomerular filtration rate 67 +/- 28 ml/min/1.73 m2}, and a matched control group of 183 patients with longstanding type 1 diabetes and persistent normoalbuminuria (111 men, age 43 +/- 10.0 years, duration of diabetes 27 +/- 8.3 years) were followed for 12.6 (0.0-12.9) years. Plasma NT-proBNP concentration was determined by immunoassay at baseline. The BNP genotypes were determined by TaqMan chemistry based assays. RESULTS: The two polymorphisms were in almost complete linkage disequilibrium (r2 = 0.883) and thus only the results of the -381T/C promoter polymorphism are shown. There was no significant difference between cases and controls in either genotype distributions (cases TT 32%, TC 53%, CC 15%; controls TT 28%, TC 52%, CC 20%) or allele frequencies (cases T/C 0.58/0.42; controls T/C 0.54/0.46) for the -381T/C polymorphism. Among the 164 normoalbuminuric patients without antihypertensive treatment and previous major cardiovascular disease (CVD), the -381T/C polymorphism was associated with circulating levels of NT-proBNP [median (interquartile range) 21 (5-32), 34 (12-67) and 32 (12-58) ng/l for TT, TC and CC, respectively (P = 0.041)] persisting after adjustment for covariates (P = 0.018). During follow-up, the -381T/C polymorphism did not predict all-cause or cardiovascular mortality among type 1 diabetic patients with or without diabetic nephropathy. CONCLUSIONS: The BNP -381T/C and 1551G/A polymorphisms are associated with circulating levels of NT-proBNP but not with prevalent overt diabetic nephropathy. These polymorphisms do not predict all-cause or cardiovascular mortality in Caucasian type 1 diabetic patients with or without diabetic nephropathy.     

Association of interleukin 18-607A/C and -137C/G polymorphisms with oxidative stress in renal transplant recipients

Objectives IL-18 mediates various inflammatory and oxidative responses including renal injury, fibrosis, and graft rejection. It has been reported that the promoter -607 and -137 polymorphisms of IL-18 influence the level of IL-18. This prospective observational study investigated the association between oxidative stress with IL-18-607 and -137 polymorphisms in renal transplant recipients. Patients and methods This study included 75 renal transplant recipients (28 female, 47 male) from living-related donors. Blood samples were collected immediately before and after transplantation at day 7 and month 1. Serum IL-18, creatinine, cystatin C, CRP, and oxidative stress markers (TOS, TAC) were measured. The Oxidative Stress Index (OSI) was calculated. Polymorphisms of the promoter region of the IL-18 gene, IL18-607A/C, and -137C/G were determined by analysis of a “real-time PCR/Melting curve”. Results Serum creatinine, cystatin C, CRP, IL-18, TOS, and OSI levels significantly decreased after transplantation. Post-transplant levels of serum TAC and estimated GFR demonstrated consistent significant increases. Serum IL-18 levels were significantly higher in patients with IL-18-137 GG and IL-18-607?CC genotypes before transplantation. Conclusion Our results indicate that the IL-18-137 GG and -607?CC genotypes contribute to higher IL-18 levels; however, the influence of these polymorphisms on oxidative stress has not been observed.     

Effect of pro-inflammatory cytokine (IFN-γ +874, IL-18–137 G/C,–607 C/A) genes in relation to risk of vesico-ureteral reflux

Aim: The aim this work is to estimate whether genetic polymorphisms of +874 of IFN-γ and ?137 G/C,?607 C/A of IL-18 genes are implicated in the development of VUR, because a vast literature indicates that genetic variations play a significant role in the pathogenesis of VUR. Materials and methods: The PCR single specific primer (SSP) and amplification refractory mutation system (ARMS) were applied for analyzing the polymorphic sites of ?137 G/C,?607 C/A of IL-18 and +874 of IFN-γ genes in 110 healthy controls and 124 VUR children. Results: A significant relationship was found between AT and combined AT + TT genotypes of IFN-γ and highly increased risk of VUR (OR?=?4.2, 95% CI, 2.00–9.24; p?0.0001: OR?=?4.00, 95% CI, 1.90–8.70, p?0.0001, respectively). On the other hand, the genotype frequency of IL18-137 G/C indicated a significant assessment of the decrease risk of VUR for GC and GC?+?CC genotypes (OR?=?0.53, 95% CI, 0.3–0.9; p?=?0.02: OR?=?0.53, 95% CI, 0.3–0.92 p?=?0.01, respectively). No significant association was found between ?607 C/A polymorphism of IL-18 and UVR. Conclusion: To the author's best knowledge, this is the first data regarding polymorphism of IFN-γ (+874) cytokine genes that highly increased the risk of VUR. To confirm the presented data, further studies should be done in different populations with a larger sample size.     

白介素-18基因多态性与结直肠癌易感性的关系

目的探讨白介素-18（m-18）基因单核苷酸多态性及其单倍型与结直肠癌易感性之间的关系。方法以170例结直肠癌患者和160名健康对照者为研究对象,应用聚合酶链反应一限制性片段长度多态性（PCR-RFLP）的方法对IL．18基因-137G／C、-607C／A单核苷酸多态性进行基因分型,同时用SHEsis软件分析IL-18基因的连锁不平衡及单倍型频率。结果IL-18基因-607C／A多态性在结直肠癌患者和健康人群中的分布差异无统计学意义（P〉0．05）．而IL-18基因-137G／C多态性在两组人群中的分布差异有统计学意义（P〈0．05）。等位基因频率的相对风险分析显示．C等位基因携带者患结直肠癌的风险是G等位基因的1．814倍（OR=1．814,95％CI：1．246～2．642）。联合基因型分析显示,IL-18基因-137G／C、-607C／A单核苷酸多态性存在着强烈的连锁不平衡（ID＇｜=0．945）,-137C／-607A单倍型频率在结直肠癌患者中显著高于健康人群（P〈0．05）。-137C／-607A单倍型携带者显著增加了结直肠癌的发病风险（OR=1．637,95％CI：1．100～2．437）。结论IL—18基因-137G／C多态性和-137C／-607A单倍型与结直肠癌的发病具有相关性．其中-137C等位基因可能是结直肠癌的遗传易感基因。     

Analysis of polymorphisms of the interleukin-18 gene in type 1 diabetes and Hardy-Weinberg equilibrium testing

Recently, the interleukin-18 cytokine gene (IL18) was reported to be associated with type 1 diabetes. In the present report, we calculated that the reported genotypes of the two 5' region/promoter single nucleotide polymorphisms (SNPs), -607 (C-->A) (rs1946518) and -137 (G-->C) (rs187238), were not in Hardy-Weinberg equilibrium (HWE). We therefore investigated the association of the -607 and -137 SNPs in a U.K. type 1 diabetic Caucasian case-control collection (1,560 case and 1,715 control subjects tested at -607 and 4,323 case and 4,610 control subjects tested at -137) as well as a type 1 diabetic Caucasian collection comprised of families of European ancestry (1,347 families tested at -137 and 1,356 families tested at -607). No evidence for association with type 1 diabetes was found, including for the -607 A/A and C/A genotypes. To evaluate whether common variation elsewhere in the gene was associated with disease susceptibility, we analyzed eight IL18 tag SNPs in a type 1 diabetic case-control collection (1,561 case and 1,721 control subjects). No evidence for association was obtained (P = 0.11). We conclude that common allelic variation in IL18 is unlikely to contribute substantially to type 1 diabetes susceptibility in the populations tested and recommend routine application of tests for HWE in population-based studies for genetic association.     

Influence of interleukin-6 promoter polymorphism -174 g/c on kidney graft outcome

Background

The cytokine interleukin-6 (IL-6) is important in both immune responses and cardiovascular diseases. The IL-6 promoter polymorphism −174 G/C is associated with increased plasma concentrations of IL-6. The relationship between IL-6 polymorphisms and graft survival, cardiovascular events, and new-onset diabetes mellitus after kidney transplantation is controversial.

Objective

To analyze whether IL-6 (−174 G/C) polymorphism influences kidney graft survival or development of chronic allograft nephropathy, cardiovascular events, or new- onset diabetes.

Methods

The IL-6 promoter polymorphism (−174 G/C) was analyzed using the polymerase chain reaction with sequence-specific primers in 335 kidney transplant recipients. Data for graft survival, chronic graft nephropathy, cardiovascular events, and new-onset diabetes were obtained retrospectively from clinical records. Categorical variables were compared between individuals with CC, GG, and GC genotypes using χ² tests. Survival analysis was performed using the Kaplan-Meier method, comparing groups using the log-rank test.

Results

No significant differences were observed in 5-year graft survival between individuals with CC and GC/GG genotypes (85.3% vs 77.1%; P = .22). Nor were significant differences noted in the rates of chronic allograft nephropathy (37.5% vs 33.8%; P = .48), cardiovascular events (10.0% vs 23.0%; P = .10), or new-onset diabetes (7.5% vs 11.8%; P = .28).

Conclusion

There is no association between IL-6 (−174 G/C) polymorphism and graft survival or development of chronic allograft nephropathy, cardiovascular events, or new- onset diabetes.     

2型糖尿病肾病患者p22phox基因多态性的研究

目的研究NADPH氧化酶p22phox亚基基因多态性与中国上海汉族人群2型糖尿病肾病（DN）相关性。方法应用限制性片断长度多态性（RFLP）-PCR方法对105例健康对照组和194例2型糖尿病（DM）患者（其中71例DN）进行p22phox亚基C242T、A640G基因型检测。同时检测其身高、体重、血压、血脂、空腹血糖及胰岛素、HbAlc的水平。结果DN组CT＋TT基因型频率明显高于2型DM和对照组（26．76％比17．07％、3．81％，P=0．0002）；DN组T等位基因频率明显高于2型DM和对照组（22．54％比13．42％、2．86％，P=0．0001）；3组间AA基因型频率与A等位基因频率差异无统计学意义。多元回归分析显示，T242等位基因、收缩压、空腹血糖、HbAlc、β细胞功能指数（Homa-IS）是DN的危险因素。结论p22phox亚基T242等位基因变异可能是中国上海地区汉族人群DN的易感基因：而p22phox亚基A640G基因多态性与上述人群DN无相关性。T242等位基因、收缩压、空腹血糖、HbAlc、Homa-IS是DN的危险因素。     

IL-18 promoter polymorphisms correlate with the development of post-injury sepsis

BACKGROUND: Interleukin (IL)-18 is a proinflammatory cytokine involved in the regulation of cell-mediated and innate immune responses to infection, trauma, and inflammation. Elevated levels of IL-18 have been noted to correlate with organ dysfunction after injury. This study evaluates the relationship between IL-18 promoter polymorphisms and the development of sepsis after injury. METHODS: DNA was extracted from peripheral leukocytes of trauma patients with an injury severity score of 16 or greater. Patient clinical course was followed for the development of sepsis as an endpoint. Two SNPs (-607bp and -137bp) were amplified using polymerase chain reaction. Alleles were identified via agarose gel separation. Genotypes were then determined and correlated with patient data. Postinjury IL-18 levels were determined by enzyme-linked immunoassay. RESULTS: Sixty-six patients were evaluated; 36 (52%) developed sepsis. Each SNP had 2 alleles and 3 genotypes. The SNP at -607bp had an allelic frequency of 59% for C and 41% for A; whereas -137bp was a G 79% of the time and a C 21% of the time. Individually, each SNP had no direct correlation between the patient's genotype and development of infection. However, when the -607bp CA genotype was combined with the -137bp GC genotype (CA/GC), only 4 patients (27%) developed sepsis (P =.02). CONCLUSIONS: This study supports the conclusion that IL-18 genetic promoter polymorphisms correlate with the development of postinjury sepsis. Further investigation is needed to identify the impact of variation in genotype across a range of genes involved in connected regulatory pathways.     

血管内皮生长因子基因多态性与糖尿病肾病的相关性研究

目的 探讨血管内皮生长因子(VEGF)-634G／C基因多态性与糖尿病肾病(DN)的关系。方法 运用PCR-限制性多态性片段长度(RFLP)技术检测98例健康对照者和216例2型糖尿病患者[其中DN患者104例，单纯2型糖尿病(DM)患者112例]的基因型，比较各组的基因型和等位基因频率。结果 (1)CC基因型者血清VEGFT水平高于CG及GG型者；(2)DN组CC基因型和C等位基因频率显著高于DM组和正常对照组；(3)与GG型和CG型组相比，CC型组DN的发生率明显上升；(4)Logistic回归分析显示VEGF、VEGF基因多态性、收缩压(SBP)、HbA1c、LDL-C、体重指数(BMI)是DN的危险因素。结论 VEGF-63gG／C多态性与2型DM伴发肾病的发生有关，C等位基因可能是DN的易感基因。     

Relationship between β1‐adrenergic receptor polymorphisms and cardiovascular disease in patients with diabetic nephropathy

Aim: Activation of β1‐adrenergic receptor (β1AR) enhances contractility and heart rate. The polymorphism Arg389Gly in the β1AR gene was found to be functionally important in determining receptor activity. The relationship between this polymorphism and the risk of cardiovascular disease was investigated in Chinese subjects with overt diabetic nephropathy. Methods: A total of 219 type 2 diabetic subjects with nephropathy were recruited. Genotyping of the β1AR Arg389Gly polymorphism was determined. Patients were followed up to 96 months for the development of cardiovascular events. Results: There were 122, 86 and 11 patients with Arg/Arg, Arg/Gly and Gly/Gly genotype, respectively. At 96 months, the event‐free survival of primary composite cardiovascular end‐point was 33.0% and 44.3% for Gly⁺ and Gly^‐ groups, respectively (log–rank test, P = 0.105), while the event‐free survival for first ischaemic heart disease was 62.4% and 75.9%, respectively (log–rank test, P = 0.038). However, with multivariate analysis by the Cox proportional hazard model to adjust for confounders, only low‐density lipoprotein and baseline glomerular filtration rate were independent predictors of first ischaemic heart event. Conclusion: The β1AR Arg389Gly polymorphism is not an independent predictor of cardiovascular events in subjects with overt diabetic nephropathy.     

The relationship of Interleukin-6 -174 G > C gene polymorphism in type 2 diabetic patients with and without diabetic foot ulcers in Turkish population

ObjectiveWe aims investigate Turkish type 2 diabetic patients with/without diabetic foot ulcers and healthy group and examined the contribution of Interleukin (IL)-6 -174 G > C gene polymorphism to the development of diabetic foot ulcers.Design and patientsThe Interleukin (IL)-6 -174 G > C genotypes were determined prospectively in 50 patients with diabetic foot ulcers and 35 without diabetic foot ulcers and a control group of 119 healthy individuals. Genotyping of the Interleukin (IL)-6 -174 G > C gene polymorphisms for all individuals was performed by PCR-RFLP method.ResultsThe genotype IL6 distribution did differ between the control group (CC 13.3%, GC 66.7%, GG 20%) and type 2 diabetic patients (CC 2.4%, GC 47.1%, GG 50.6%) (P < 0.001). The genotype IL6 distribution did not differ between type 2 diabetic patients group (CC 0%, GC 45.7%, GG 54.3%) and diabetic foot ulcers (CC 4%, GC 48%, 48%) (P > 0.05). The frequency of the polymorphic G allele in between the control group and type 2 diabetic patients was no similar for the groups (58.4% and 74.1%, respectively) (p < 0.05). The frequency of the polymorphic G allele in between the type 2 diabetic patients and diabetic foot ulcers was similar for the groups (77.1% and 72%, respectively) (p > 0.05).ConclusionThe gene polymorphism of Interleukin-6 -174 G > C and G allele are an risk factor for diabetes, but gene polymorphism of Interleukin-6 -174 G > C is not an independent risk factor for diabetic foot. Genetic factors in the pathogenesis of diabetic foot may also show any changes in different populations.     

Improved prognosis in type 1 diabetic patients with nephropathy: a prospective follow-up study

BACKGROUND: In early studies, a median survival time of 5 to 7 years from onset of diabetic nephropathy was observed. Furthermore, end-stage renal disease (ESRD) was the main cause of death. We prospectively assessed the impact of reno- and cardiovascular protective treatment on prognosis in type 1 diabetic patients with diabetic nephropathy. METHODS: We prospectively followed 199 type 1 diabetic patients with diabetic nephropathy and 192 patients with normoalbuminuria for 10 years. Aggressive antihypertensive treatment was initiated in patients with diabetic nephropathy in mid 1980s, whereas statins and aspirin were not prescribed routinely until April 2002. The primary end point was cardiovascular mortality and morbidity. Secondary end points were all-cause mortality and ESRD. RESULTS: During follow-up, 79 patients (40%) with nephropathy reached the primary end point versus 19 (10%) of normoalbuminuric patients, log rank test P < 0.0001. Predictors of the primary end point were: nephropathy (hazard ratio 3.26; 95% confidence interval 1.89 to 5.62), previous event (3.19; 2.04 to 4.97), age (1.27; 1.04 to 1.55), and systolic blood pressure (1.13; 1.03 to 1.24). In the nephropathy group, 60 patients (30%) died; hereof, 25 deaths (42%) were ascribed to cardiovascular causes while 30 patients (50%) with nephropathy died with ESRD. The estimate of median survival time from onset of diabetic nephropathy was 21.7 years, SE 3.3 years. CONCLUSION: The survival of patients with diabetic nephropathy has improved most likely due to aggressive antihypertensive treatment and improved glycaemic control.     

Polymorphisms in interleukin-1 beta and Interleukin-1 receptor antagonist genes are associated with kidney failure in Korean patients with type 2 diabetes mellitus

BACKGROUND/AIM: Cytokines play an important role in the pathogenesis of kidney diseases. The aim of the study was to investigate the impact of interleukin (IL)-1 cluster genes on diabetic nephropathy in Korean patients with type 2 diabetes mellitus (DM). METHODS: We investigated -511 C/T polymorphism of IL-1 beta and tandem repeat polymorphism in intron 2 of IL-1 receptor antagonist in type 2 DM patients with end-stage kidney failure as compared with patients without nephropathy. RESULTS: The IL1B2 allele was found more frequently in patients with kidney failure than in controls (57.4 vs. 46.1%, p < 0.05). An excessive homozygous carriage of IL1B2 was found in patients with kidney failure when compared with controls (30.5 vs. 18.3%, p < 0.05). The allelic frequency of IL1RN*2 was also higher in cases than in controls without nephropathy (8.4 vs. 2.8 %, p < 0.05). The carriage rate of IL1RN*2 was significantly associated with an increased risk of kidney failure (15.8 vs. 5.6%; OR 3.19, 95% CI 1.24-8.17). The risk of kidney failure was highest in those carrying both IL1RN*2 and IL1B2 (OR 3.90, 95% CI 1.34-11.40). CONCLUSION: IL1B2 and IL1RN*2 genotypes of the IL-1 cluster genes are associated with diabetic nephropathy in Korean patients with type 2 DM.     

Association of polymorphisms within the transforming growth factor-β1 gene with diabetic nephropathy and serum cholesterol and triglyceride concentrations

Aim: The TGF‐β gene participates in the development of chronic kidney disease. We investigated whether the 869 T > C, 915 G > C and ?800 G > A polymorphisms of TGF‐β1 are associated with diabetic nephropathy (DN). Methods: Polymorphisms were genotyped in 439 type 2 diabetes mellitus patients, 233 with diabetic nephropathy (DN+) and 206 without (DN–). The sample was characterized for relevant clinical and biochemical parameters. Results: The 869 T > C (P = 0.016; odds ratio (OR) = 1.818, 95% confidence interval (CI) = 1.128–2.930) and the 915 G > C polymorphisms (P = 0.008, OR = 4.073, 95% CI = 1.355–12.249) were associated with diabetic nephropathy. The 869 T > C variant was associated with total cholesterol levels: CC + CT genotypes had a mean cholesterol concentration of 5.62 ± 1.40 mmol/L vs a mean concentration of 5.15 ± 1.40 mmol/L for the TT genotype (P = 0.011). Triglycerides were also higher in CC + CT genotypes (2.49 ± 1.56 mmol/L) in comparison with TT homozygotes (2.1 ± 1.22 mmol/L, P = 0.042). Multivariate logistic regression showed that the polymorphisms 869 T > C and 915 G > C were independent predictors for DN (P = 0.049 and 0.046, respectively). Conclusion: The 869 T > C and 915 G > C polymorphisms within the TGF‐β1 gene were associated with DN+. Lower cholesterol and triglycerides levels were observed in TT homozygotes for the 869 T > C polymorphism. The TGF‐β1 869 T allele seems to confer protection against DN+.     

IL‐16 polymorphism and risk of renal cell carcinoma: Association in a Chinese population

Objectives: Interleukin‐16 (IL‐16) plays a fundamental role in inflammatory diseases, as well as in the development and progression of tumors. A T‐to‐C polymorphism at the ‐295 position in the promoter region of the IL‐16 gene has been described. This variation might lead to altered IL‐16 expression, and might modulate an individual's susceptibility to cancer. The objective of the present study was to determine if IL‐16 polymorphism is associated with risk of renal cell carcinoma (RCC). Methods: A case–control study including 335 RCC cases and 340 cancer‐free controls was carried out. All subjects were genetically unrelated ethnic Han Chinese recruited from a single institution between July 2006 and July 2009. The IL‐16 ‐295 T>C polymorphism was determined by using the polymerase chain reaction‐restriction fragment length polymorphism method. Serum samples were available for 70 RCC cases and 96 controls to detect IL‐16 concentration. Results: Compared with the IL‐16 ‐295 TT genotype, the CC genotype had a significantly decreased RCC risk (adjusted odds ratio [OR] = 0.34, 95% confidence interval [CI] = 0.18–0.66). Furthermore, a significant decreased risk of RCC was found in the combined variant genotypes CT + CC compared with the TT genotype (adjusted OR = 0.68, 95% CI = 0.50–0.93). In addition, the serum IL‐16 levels in RCC patients were significantly lower than those in controls (P < 0.001). Furthermore, patients carrying CC genotype or CT genotype had higher serum IL‐16 levels than TT carriers. Conclusion: IL‐16 ‐295 T>C polymorphism is significantly associated with a higher risk of developing RCC in Chinese population.     

Association between interleukin-10 gene polymorphism -592 (A/C) and peritoneal transport in patients undergoing peritoneal dialysis

Aim: The aim of this analysis was to know whether these three cytokine polymorphisms, including interleukin‐6 (IL‐6; ?572 G/C), tumour necrosis factor‐α (TNF‐α; ?308 G/A), and IL‐10 (–592 A/C) have an effect on baseline peritoneal transport property and longitudinal evolution of peritoneal function. Methods: A total of 141 stable peritoneal dialysis (PD) patients with mean treatment duration of 84.4 ± 34.2 months were enrolled. We genotyped these three cytokine polymorphisms, together with clinical parameters that were included as factors affecting longitudinal change of property of peritoneal transport over the first 3 year period after commencing therapy. Results: There was no significant association between genotypes and baseline peritoneal transport property. The ?592 A/C polymorphism of IL‐10 was associated with longitudinal change of peritoneal transport. The ratio of D/P creatinine was significantly higher in patients with AA than those with CC/CA genotypes at 12 months (0.65 ± 0.11 vs 0.62 ± 0.09, P = 0.048) and 24 months (0.64 ± 0.12 vs 0.59 ± 0.09, P = 0.018). In addition, patients with increased peritoneal transport have greater frequency distribution of AA genotype and A allele. Logistic regression analysis revealed that ?592 A allele was an independent predictor for the increase in D/P creatinine over the first 12 month period (odds ratio: 2.482, P = 0.017). There was no correlation between either polymorphism of IL‐6 ?572 (G/C) or TNF‐α?308 (G/A) and longitudinal change of peritoneal function. Conclusions: Single nucleotide polymorphism of IL‐10 ?592 (A/C) was associated with longitudinal evolution of peritoneal transport rate in PD patients rather than the baseline peritoneal characteristics.     

Dopamine D3 receptor gene polymorphisms, blood pressure and nephropathy in type 1 diabetic patients.

BACKGROUND: Dopamine modulates blood pressure in the kidney. The aim of this study was to investigate whether two previously known (-707 G/C, Ser9Gly) and one novel (Ala17Ala) polymorphism in the dopamine D3 receptor gene and/or their haplotypes are associated with blood pressure, diabetic nephropathy or renal variables in the study subjects. METHODS: A cross-sectional, case-control study with a total of 996 type 1 diabetic patients from the multicentre, nationwide FinnDiane Study. Patients were recruited consecutively and classified into four groups according to their renal status. RESULTS: The frequencies of the genotypes harbouring the minor allele were 33, 51 and 19% for the -707 G/C, Ser9Gly and Ala17Ala polymorphisms, respectively. Frequencies of the -707 G/C minor genotypes were 35 (normoalbuminuria), 32 (microalbuminuria), 28 (proteinuria) and 39% (end-stage renal disease) (chi(2) = 6.3, df = 3, P = 0.1), of the Ser9Gly 52, 51, 46 and 57% (chi(2) = 6.3, df = 3, P = 0.1) and of the Ala17Ala polymorphism 18, 19, 19 and 21% (chi(2) = 0.7, df = 3, P = 0.9), respectively. Five haplotypes were identified, but no differences were seen between those with and without diabetic nephropathy. Furthermore, there were no differences in blood pressure levels nor in any renal variables between genotypes or haplotypes. CONCLUSIONS: These results do not provide evidence for an involvement of the dopamine D3 receptor gene in blood pressure levels or in the pathogenesis of diabetic nephropathy in type 1 diabetic patients.     

Investigation of the human ANP gene in type 1 diabetic nephropathy: case-control and follow-up studies

The atrial natriuretic peptide gene (PND) is a candidate gene for diabetic nephropathy. We systematically analyzed five nonsynonymous PND polymorphisms and tested the association of genotype and haplotype distributions with diabetic nephropathy in a cross-sectional study and a 6-year follow-up study (489 and 301 type 1 diabetic patients, respectively). For this purpose, a new maximum-likelihood method dealing with haplotype-based association analysis for survival data was developed. None of the genotypes or haplotypes were associated with the disease in the case-control study. In the follow-up study, C708T and T2238C showed a weak association with disease progression, but T2238C was strongly associated with progression in poorly controlled subjects (mean HbA(1c) during follow-up was more than the median value [8.5%]; log-rank [TC or CC versus TT], P = 0.007; adjusted hazard ratio, TC or CC versus TT, 2.28, 95% CI 1.10-4.74; P = 0.027). The raw effect of the 2238C allele (hazard risk ratio 1.93, 95% CI 1.15-3.24; P = 0.012) was further confirmed by the haplotype analysis, suggesting that the 2238C allele of PND may affect the course of nephropathy in inadequately controlled type 1 diabetic patients.     

No association between a genetic variant of the p22(phox) component of NAD(P)H oxidase and the incidence and progression of IgA nephropathy.

BACKGROUND: The course of glomerulonephritis varies even within the same histological entity, which suggest that genetic factors determine the progression of inflammatory renal diseases. We studied a potential relationship between the C242T gene polymorphism of p22(phox), a subunit of the NAD(P)H oxidase, and frequency as well as progression of immunoglobulin A (IgA) nephropathy. Patients with lupus nephritis were also investigated. The distribution of the C242T gene variation of p22(phox) has not been previously studied in patients with renal disease. METHODS: Patients with IgA nephropathy were from a homogenous ethnic group of patients living in Northern Germany (n=127). Patients with active lupus nephritis WHO classes III/IV (n=46) were also studied. All diagnoses were confirmed by renal biopsy. Healthy blood donors (n=151) exhibited a genotype distribution similar to previously reported values for Caucasians (CC, 41.2%; CT, 45%; TT, 13.8%). However, C242T genotype distribution was not significantly different (chi(2) test) in patients with IgA nephropathy (CC, 44.9%; CT, 48%; TT, 7.1%) or in active lupus nephritis (CC, 54.3%; CT, 34.7%; TT, 11%). Grouping of IgA nephropathy patients as those with mild renal impairment at the time of biopsy (serum creatinine <1.3 mg/dl) and those with more severe renal failure (serum creatinine >1.3 mg/dl) also failed to show a relationship with p22(phox) polymorphism. Log-rank analysis for up to 15 years in selected cases of IgA nephropathy did not show a significant difference in renal survival rate among the three genotypes. CONCLUSIONS: It appears that the C242T polymorphism is not associated with IgA nephropathy or active lupus nephritis and may not affect the progressive deterioration of renal function in patients with IgA nephropathy. However, whether the C242T polymorphism plays a role in other renal diseases remains to be studied.     

Association of TNF‐α, TGF‐β1, IL‐10, IL‐6, and IFN‐γ gene polymorphism with acute rejection and infection in lung transplant recipients

Infection and rejection are common complications faced by lung transplant recipients (LTRs) and have become major impediments to long‐term survival. Cytokines may play an important role in the development of these complications. In this study, we explored the correlation between TNF‐α (?308 A/G), TGF‐β1 (+869 T/C, +915 G/C), IL‐10 (?592 C/A, ?819 T/C, ?1082 G/A), IL‐6 (?174 G/C), and IFN‐γ (+874 T/A) gene polymorphisms and the incidence of acute rejection and infection. Transplant outcomes were reviewed in a retrospective cohort of 113 LTRs from a single center between December 2004 and November 2012. Cytokine polymorphisms were measured using sequence‐specific primer‐based PCR. HLA typing was performed for the donors and recipients. We found that the LTRs with the IL‐10 ?819 CC and ?592 CC genotypes had a significantly decreased risk of infection (p = 0.017, OR = 0.177, 95% CI = 0.04–0.85). However, we found no significant association between cytokine polymorphisms and acute rejection. Furthermore, the data revealed that the occurrence of acute rejection was strongly associated with infection episodes (χ² = 8.5256, p < 0.01). These results suggest that LTRs possessing the IL‐10 ?819 CC and ?592 CC genotype may be protected from the occurrence of infection. Our results demonstrated that infection is an important cause of acute rejection for LTRs.