The Influence of the Endothelin-Converting Enzyme-1 Gene Polymorphism on the Progression of Autosomal Dominant Polycystic Kidney Disease

Background. A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD), the most common renal hereditary disease. Endothelin-1 (ET-1) has been suggested to be an important disease-promoting factor of the kidney. Endothelin-converting enzyme-1 (ECE-1) is the main protease responsible for ET-1 generation by cleavage of its functionally inactive precursor. We examined the influence of the ECE-1b C-338A polymorphism on the progression of ADPKD toward end-stage renal disease (ESRD). The A allele was suggested to be associated with higher plasma level of ET-1. Methods. 200 ADPKD patients (107 males, 93 females) who had reached ESRD were analyzed. Patients were divided into three groups: (1) 47 patients (23 males, 24 females) with ESRD later than in 63 yr (slow progressors); (2) 71 patients (38 males, 33 females) with ESRD before 45 yr (rapid progressors); and (3) 82 patients (46 males, 36 females) with ESRD between 45–63 yr. Moreover, we analyzed 160 genetically unrelated healthy Czech subjects as the control group (82 males, 78 females, mean age 51.4 ± 8.2 yr). DNA samples from collected blood were genotyped for ECE-1b C-338A polymorphism using described polymerase chain reaction (PCR) followed by restriction enzyme digestion. We compared the frequencies of different genotypes between the groups of slow and rapid progressors and the ages of ESRD with regard to different genotypes. Results. The ECE-1b C-338A genotype distribution showed no differences among the groups of slow progressors, rapid progressors, ADPKD group with ESRD between 45–63 yr and control group. Comparing the ages of ESRD of all patients, we did not find significant differences in the ages with regard to different genotypes: CC (51.5 ± 10.1 yr), AC (51.6 ± 11.4 yr), AA (48.2 ± 5.9 yr). There was a tendency to lower age of ESRD in AA homozygotes in comparison with other genotypes (t-test, p = 0.12). We found no influence of gender. Conclusion. We excluded the effect of ECE-1b C-338A polymorphism on the progression of ADPKD. We could observe a mild tendency toward faster decline of renal function in AA homozygous individuals.     

Influence of endothelin-1 gene polymorphisms on the progression of autosomal dominant polycystic kidney disease

BACKGROUND/AIM: A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD). The variability cannot be fully explained by the genetic heterogeneity of the disease. Endothelin-1 (ET-1) has been suggested to be a major promoting factor in renal diseases. The role of the ET-1 gene locus (EDN1) in the renal function in the general nondiabetic population was evaluated. We examined the influence of three single-nucleotide polymorphisms of the ET-1 gene (EDN1)--K198N, 3A/4A, and T-1370G--on the progression of ADPKD towards end-stage renal disease (ESRD). METHODS: Two hundred and five ADPKD patients (113 males and 92 females) who had reached ESRD were analyzed. The patients were divided into three groups: (1) 48 patients (23 males and 25 females) with ESRD later than 63 years of age (slow progressors), (2) 74 patients (41 males and 33 females) with ESRD before 45 years of age (rapid progressors), and (3) 83 patients (49 males and 34 females) with ESRD between 45 and 63 years old. DNA samples from collected blood were genotyped for three single-nucleotide polymorphisms of EDN1: K198N, 3A/4A, and T-1370G. Haplotype analysis was also done in 200 healthy individuals. We compared the frequencies of the different genotypes between the groups of slow and rapid progressors and the ages at the time of ESRD regarding the EDN1 genotypes. RESULTS: The EDN1 genotype distribution showed no differences among the groups of slow progressors, rapid progressors, the ADPKD group with ESRD between 45 and 63 years old, and the control group. Comparing the ages of ESRD of all patients, we did not find significant differences with regard to the different genotypes. Furthermore, we compared the combinations of the different haplotypes and the ages at the time of ESRD. We found no differences in ages at the time of ESRD in patients with different haplotypes in the endothelin promoter (T-1370G) in combination with 3A/4A or K198N polymorphisms. Comparing the ages at the time of ESRD in patients with different 3A/4A and K198N haplotypes, we found a significantly lower age at the time of ESRD (47.1 +/- 8.7 years) in the carriers of the 4A allele in combination with the 198N allele (4A/4A, 3A/4A + 198KN,NN) than in the carriers of the 4A allele homozygous for the K198 allele (52.9 +/- 10.9 years; 4A/4A, 3A/4A + 198KK; t test: p < 0.01) and in the carriers of the 198N allele homozygous for the 3A allele (53 +/- 11.2 years; 3A/3A + 198KN,NN; t test: p < 0.05). CONCLUSIONS: We excluded an effect of K198N, 3A/4A, and T-1370G polymorphisms of EDN1 on the progression of ADPKD. However, a deleterious effect of the combination of 4A and 198N alleles of EDN1 was observed in APKDK individuals.     

The influence of G-protein beta3-subunit gene and endothelial nitric oxide synthase gene in exon 7 polymorphisms on progression of autosomal dominant polycystic kidney disease

BACKGROUND: A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD). The variability cannot be fully explained by the genetic heterogeneity of the disease. We examined the influence of G-protein beta3-subunit C825T polymorphism and endothelial nitric oxide synthase Glu298Asp polymorphism on the progression of ADPKD towards end stage renal failure (ESRF). METHODS: 306 ADPKD patients (pts) were analyzed; 261 pts (136 males, 125 females) with ESRF, with subgroup of 73 pts (44 males, 29 females) with ESRF before 45 years (rapid progressors), 46 pts (20 males, 26 females) with ESRF later than in 63 years (slow progressors) and 45 ADPKD pts (17 males, 28 females) in mean age 51 years with serum creatinine under 110 micromol/L (slow progressors) and 100 genetically unrelated healthy Czech subjects. DNA samples from collected blood were genotyped for G-protein beta3-subunit C825T genotype in exon 10 and for endothelial nitric oxide synthase Glu298Asp genotype in exon 7. RESULTS: The G-protein beta3-subunit C825T genotype exhibited no significant differences among the groups of slow progressors (6.6% (6/91) TT, 54.9% (50/91) CT, 38.8% (35/91) CC), rapid progressors (9.6% (7/73) TT, 46.6% (34/73) CT, 43.8% (32/73) CC), ADPKD group with ESRF between 40-63 years (9.2% (13/142) TT, 50% (71/142) CT, 40.8% (58/142) CC) and control group (12% TT, 44% CT, 44% CC). When comparing the ages of ESRF of all patients with ESRF, we did not find significant differences in the ages: males TT--51.7+/-8.8 years, CT--51.9+/-10.3 years, CC--49.7+/-10.2 years and females TT--56+/-9.9 years, CT--53.2+/-8.5 years, CC--53.9+/-8.7 years. The endothelial nitric oxide synthase Glu298Asp and Asp29Asp genotypes were significantly more frequent in rapid progressors (9.6% (7/73) Asp/Asp, 39.7% (29/73) Asp/Glu, 50.7% (37/73) Glu/Glu) and in ADPKD group with ESRF between 40-63 years (11.3% (16/142) Asp/Asp, 41.5% (59/142) Asp/Glu, 47.2% (67/142) Glu/Glu) in comparison with slow progressors (8.8% (8/91) Asp/Asp, 24.2% (22/91) Asp/Glu, 67.0% (61/91) Glu/Glu) and with control group (8% Asp/Asp, 32% Asp/Glu, 60% Glu/Glu) (Chi-square test, p<0.05). Comparing the ages of ESRF of all patients with ESRF, we did not find significant differences in the ages in males with Asp/Asp--54.9+/-10.4 years, Asp/Glu--50.2+/-9.4 years, Glu/Glu--51.0+/-10.4 years. We found out in homozygous Asp/Asp females significantly earlier onset of ESRF (49.2+/-5.6 years) in comparison with heterozygous females (53.3+/-7.2 years) and with Glu/Glu homozygous females (54.8+/-9.7 years) (t-test, p<0.05). CONCLUSION: We excluded the significance of G-protein beta3-subunit C825T polymorphism on the progression of ADPKD. We established the negative prognostic value of the carriers of Asp variant of eNOS polymorphism. Finding of new modifiers could have in future clinical consequences for ADPKD patients.     

Association between the A1166C polymorphism of the angiotensin II receptor type 1 and progression of chronic renal insufficiency

BACKGROUND: In some studies genetic variation in the renin-angiotensin-aldosterone system (RAAS) has been associated with hypertension and rapid progression of renal insufficiency to end-stage renal disease (ESRD). Most of these studies do not take into account covariables influencing progression. We studied retrospectively the role of angiotensinogen (AGT) M235T, angiotensin converting enzyme (ACE) insertion/deletion (I/D), angiotensin II type 1 receptor (AT1R) A1166C, aldosterone syntase (CYP11B2) -344C/T and intron 2 W/C polymorphisms in conjunction with clinical and biochemical covariables on the rate of progression of renal insufficiency in a group of patients with ESRD of various etiologies. METHODS: Genotyping was performed by polymerase chain reaction (PCR) in 104 ESRD patients (62 males and 42 females), aged 64 +/- 14 years (mean +/- SD) with mean initial serum creatinine of 2.6 +/- 1.1 mg/dL and a mean time to reach ESRD of 52 +/- 38 months. RESULTS: The univariate analysis showed that there was a significant difference in the values of the slopes among the AT1R A1166C polymorphism genotypes: AA -4.87 +/- 0.22, AC -5.09 +/- 0.65 and CC -5.52 +/- 0.66 (p<0.05). None of the remainder polymorphisms showed significant association with progression. Stepwise multiple regression analysis including all the clinical, biochemical and genetic variables showed that only systolic blood pressure (SBP), serum PTHi and AT1R genotype were independently associated with the rate of progression, excluding the other variables from the model. CONCLUSIONS: These results indicate that susceptibility to faster progression to ESRD is associated with the AT1R A1166C polymorphism. This association remains significant after adjustment for relevant covariates, highlighting the importance of analyzing genetic risk factors in the context of clinical and biochemical variables.     

Influence of ACE (I/D) and G460W polymorphism of alpha-adducin in autosomal dominant polycystic kidney disease.

BACKGROUND: The deleterious effect of the DD genotype of ACE in autosomal dominant polycystic kidney disease (ADPKD) remains controversial. Small sample size, population admixture and lack of consideration of parameters modulating the effects of ACE genotype, such as gender or alpha-adducin (ADD) genotype, might explain the discrepancy. METHODS: We investigated the effect of ACE (I/D) polymorphism on the age at end-stage renal disease (ESRD) in a homogeneous population of 191 ADPKD patients, according to gender and genotype for the G460W polymorphism of ADD. Cumulative renal survival was assessed in 276 patients from the same families. RESULTS: Though no effect was detected in the whole population, analysis of the male subset (n = 97) showed that patients harbouring the DD genotype of ACE had a 5-year lower mean age at ESRD than DI + II patients [47.8 +/- 1.8 (n = 31) vs 52.8 +/- 1.1 (n = 66), respectively] (P = 0.02). Furthermore, cumulative renal survival was lower in the corresponding pedigrees [47 +/- 1 years, 95% confidence interval (CI) 45-49, vs 51 +/- 1 years, 95% CI 48-54]. The G460W polymorphism of ADD had no effect on the age at ESRD and cumulative renal survival, either alone or in combination with the ACE (I/D) polymorphism. CONCLUSIONS: In this large series of ADPKD patients, we found no effect of the ACE (I/D) polymorphism on the age at ESRD, either alone or in combination with the G460W polymorphism of ADD. However, a deleterious effect of the DD genotype of ACE on renal disease progression was observed in ADPKD males.     

Association of interleukin-10 gene G-1082A polymorphism with the progression of primary glomerulonephritis

BACKGROUND: Interleukin-10 (IL-10) is a cytokine with immunosuppressive properties. We evaluated the influence of G-1082A polymorphism in the IL-10 gene promoter, which has been associated with modified IL-10 production, on the two most common forms of primary glomerulonephritis: IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS). METHODS: We studied Caucasian patients (N= 191) with biopsy-proven glomerulonephritis (IgAN: N= 123, FSGS: N= 68) followed-up for 6.5 +/- 5.5 years. Patients were classified according to the slope of reciprocal serum creatinine (>/= or <-0.1 dL(*)mg(-1) (*)year(-1)) into group A (slow progressors, IgAN: N= 75, FSGS: N= 47) and group B (fast progressors, IgAN: N= 48, FSGS: N= 21). One hundred healthy volunteers were analyzed as control patients. G-1082A polymorphism was determined by polymerase chain reaction (PCR) amplification. RESULTS: The allele frequencies were similar in patients and control group (NS). Initial renal function, proteinuria, and blood pressure did not differ significantly between patients with different genotypes. G-1082A polymorphism was associated with the progression of both IgAN and FSGS: GA/AA genotypes were more frequent in group B (fast progressors) than in group A (slow progressors; P= 0.012 for IgAN, P < 0.05 for FSGS). Patients with the GA/AA genotypes showed a worse outcome in the Kaplan-Meier analysis of renal survival (P < 0.05 for both IgAN and FSGS). The IL-10 polymorphism remained an independent risk factor for progression in multivariate analysis (Cox regression model, P < 0.05 for IgAN and FSGS). CONCLUSION: Our results suggest that IL-10 gene G-1082A polymorphism is an important marker of progression in patients with IgAN and FSGS.     

Renal structure and hypertension in autosomal dominant polycystic kidney disease

Hypertension has been reported to occur in 50 to 75 percent of subjects with autosomal dominant polycystic kidney disease (ADPKD) prior to the onset of marked renal insufficiency but concurrent with cystic deformation of the renal parenchyma. The present study was undertaken to examine whether the renal structural abnormalities are greater in hypertensive (HBP) versus normotensive (NBP) male and female patients with ADPKD who were matched within gender groups for age, body surface area, serum creatinine concentration (males HBP 1.2 +/- 0.02 vs. NBP 1.1 +/- 0.03 mg/dl. NS: females HBP 0.9 +/- 0.03 vs. NBP 0.9 +/- 0.02 mg/dl, NS) and creatinine clearance (males HBP 100 +/- 3 vs. NBP 108 +/- 3 ml/min/1.73 m2, NS: females HBP 97 +/- 3 vs. NBP 96 +/- 2 ml/min/1.73 m2, NS). Renal volume was significantly greater in the HBP compared to the NBP group (males HBP 624 +/- 47 vs. NBP 390 +/- 43 cm3, P less than 0.0005; females HBP 446 +/- 32 vs. NBP 338 +/- 24 cm3, P less than 0.002). Since increased renal volume is due to increased cysts, the results indicate that the early high incidence of hypertension in ADPKD correlates with the renal structural abnormalities in this disorder.     

Influence of the endothelial nitric oxide synthase polymorphism on the progression of autosomal dominant polycystic kidney disease and IgA nephropathy

BACKGROUND: The reason of variability of clinical course and progression to end-stage renal failure (ESRF) of two widespread chronic nephropathies--autosomal dominant polycystic kidney disease (ADPKD) and IgA nephropathy (IGAN) is not clear. The endothelial dysfunction is considered in the number of factors possibly influencing the prognosis of these nephropathies. Our study tried to verify the hypothesis that endothelial nitric oxide synthase (ecNOS) gene polymorphisms in intron 4 could have some relevance to the progression of ADPKD and/or IgA nephropathy. METHODS: We examined 128 Czech patients with ADPKD (62 males, 66 females) and 93 patients with IGAN (51 males, 42 females). As a control group, we used 100 genetically unrelated healthy subjects (50 men, 50 women, mean age 51.2 +/- 8.2). The genomic DNA was amplified by polymerase chain reaction (PCR) and the products were separated on 1.5% agarose gel and visualized by ultraviolet transillumination. We compared homozygous subjects for ecNOSb allele with homozygous and heterozygous subjects for ecNOSa allele. RESULTS: The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 19% (19/100) and 81% (81/100) in the control group. The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes in ADPKD patients were: 26.6% (8/30) and 73.4% (22/30) in ADPKD patients with normal renal function, 30% (9/30) and 70% (21/30) in ADPKD with ESRF, 35.2% (18/51) and 64.8% (33/51) in young ADPKD patients, 60% (12/20) and 40% (8/20) in ADPKD patients with ESRF later than in 62 years. In IGAN, the frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 24% (12/50) and 76% (38/50) in IgA with normal renal function and 20.9% (9/43) and 79.1% (38/43) in IgA with ESRF. CONCLUSION: Both in ADPKD and IGAN groups, there was no significant difference in the frequencies of ecNOS genotypes between patients with normal renal function and age matched patients with ESRF and between patients with normal renal function and control group. The frequency of ecNOSa allele was significantly higher in a number limited group ADPKD patients with ESRF later than in 62 years (Chi-square test p < 0.05). This higher frequency of a allele among ADPKD patients with later onset of ESRF could suggest the trend of positive influence of a allele in ADPKD patients.     

Influence of the endothelial nitric oxide synthase polymorphism on the progression of autosomal dominant polycystic kidney disease and IgA nephropathy

BACKGROUND: The reason of variability of clinical course and progression to end-stage renal failure (ESRF) of two widespread chronic nephropathies-autosomal dominant polycystic kidney disease (ADPKD) and IgA nephropathy (IGAN) is not clear. The endothelial dysfunction is considered in the number of factors possibly influencing the prognosis of these nephropathies. Our study tried to verify the hypothesis that endothelial nitric oxide synthase (ecNOS) gene polymorphisms in intron 4 could have some relevance to the progression of ADPKD and/or IgA nephropathy. METHODS: We examined 128 Czech patients with ADPKD (62 males, 66 females) and 93 patients with IGAN (51 males, 42 females). As a control group we used 100 genetically unrelated healthy subjects (50 men, 50 women, mean age 51.2 +/- 8.2). The genomic DNA was amplified by polymerase chain reaction (PCR) and the products were separated on 1.5% agarose gel and visualized by ultraviolet transillumination. We compared homozygous subjects for ecNOSb allele with homozygous and heterozygous subjects for ecNOSa allele. RESULTS: The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 19% (19/100) and 81% (81/100) in the control group. The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes in ADPKD patients were: 26.6% (8/30) and 73.4% (22/30) in ADPKD patients with normal renal function, 30% (9/30) and 70% (21/30) in ADPKD with ESRF, 35.2% (18/51) and 64.8% (33/51) in young ADPKD patients, 60% (12/20) and 40% (8/20) in ADPKD patients with ESRF later than in 62 years. In IGAN the frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 24% (12/50) and 76% (38/50) in IgA with normal renal function and 20.9 % (9/43) and 79.1% (38/43) in IgA with ESRF. Conclusion: Both in ADPKD and IGAN groups there was no significant difference in the frequencies of ecNOS genotypes between patients with normal renal function and age matched patients with ESRF and between patients with normal renal function and control group. The frequency of ecNOS a allele was significantly higher in a number limited group ADPKD patients with ESRF later than in 62 years (Chi-square test p < 0.05). This higher frequency of a allele among ADPKD patients with later onset of ESRF could suggest the trend of positive influence of a allele in ADPKD patients.     

The ACE insertion/deletion polymorphism has no influence on progression of renal function loss in autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) shows a variable clinical course that is not fully explained by the genetic heterogeneity of this disease. We looked for a possible genetic modifier, the ACE I/D polymorphism, and its influence on progression towards end-stage renal failure (ESRF). METHODS: Forty-nine ADPKD patients who reached ESRF <40 years, and 21 PKD1 patients who reached ESRF > 60 years or were not on dialysis at 60 years of age were recruited. Clinical data were provided by questionnaires. Blood was collected for the determination of the ACE insertion/deletion (I/D) polymorphism genotype. The ACE genotype was also determined in a general, control PKD1 group (n=59). RESULTS: Patients who reached ESRF <40 years had significantly more early onset hypertension than patients reaching ESRF >60 years (80% vs 21%; P<0.001). The ACE genotype distribution showed no differences between the groups of the rapid progressors (DD 20%, ID 56%, II 24%), the slow progressors (DD 29%, ID 52%, II 19%) and the general PKD1 control population (DD 31%, ID 47%, II 22%). CONCLUSION: There is no relationship between progression towards ESRD and the ACE I/D polymorphism in ADPKD patients.     

Epidemiological study of kidney survival in autosomal dominant polycystic kidney disease

BACKGROUND: It is unknown whether the substantial increase in research, identification of risk factors for renal progression, greater antihypertensive armamentarium including inhibitors of the renin-angiotensin-aldosterone system (RAAS) and enhanced educational information have impacted the progression of autosomal dominant polycystic kidney disease (ADPKD) renal disease. METHODS: An epidemiological study involving 513 ADPKD subjects was performed. The hypothesis tested was that over two separate periods, 1985 to 1992 versus 1992 to 2001, a significant slowing of renal function loss in ADPKD patients would be demonstrated in association with improved blood pressure (BP) control and inhibition of the RAAS as instituted by their primary care physicians. RESULTS: ADPKD males and females in the later cohort (1992 to 2001) had longer mean and median survival times to ESRD than males and females in the earlier cohort (1985 to 1992). Analysis revealed that both males and females in the later cohort had significantly lower diastolic blood pressure (DBP) and mean arterial pressure (MAP) values than males and females in the earlier cohort. ADPKD male and female patients in the later cohort used significantly more angiotensin converting enzyme inhibitors (ACEIs) than ADPKD male and female patients in the earlier cohort. CONCLUSIONS: These results demonstrate a significant slowing of ADPKD renal progression in both male and female patients that was associated with a significantly lower MAP and increased use of ACEIs in the later cohort (1992 to 2001) as compared to the early cohort (1985-1992).     

No effect of angiotensin-converting enzyme gene polymorphism on disease progression and left ventricular hypertrophy in autosomal dominant polycystic kidney disease

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) shows a variable clinical course suggesting that genetic modifiers might play a role. There are conflicting results about the effect of angiotensin-converting enzyme (ACE) gene polymorphism on the progression of renal failure in ADPKD. Also, the association between ACE gene polymorphism and the occurrence of left ventricular hypertrophy (LVH) has not been investigated in patients with ADPKD. METHODS: ACE genotype analysis was performed in 409 Caucasian patients (137 male, 272 female) with ADPKD. Echocardiographic examination was done in 164 of these patients. RESULTS: There were no significant differences between different ACE genotypes regarding renal function, renal volume, urinary protein excretion, blood pressure, the rate of hypertension, the age at diagnosis of hypertension, the rate of LVH and the incidence of end-stage renal disease (ESRD). CONCLUSION: ACE gene polymorphism does not have a significant effect on the development of ESRD and the prevalence of LVH in patients with ADPKD.     

Endothelin-converting enzyme activity in human cerebral circulation

OBJECTIVE: An increased level of endothelin (ET)-1 seems to be involved in the development of augmented cerebrovascular resistance in different pathological conditions, most notably vasospasm after subarachnoid hemorrhage. Therefore, interfering with the ET synthesis or ET receptor blockade may be a promising approach in the treatment of cerebral vasospasm after subarachnoid hemorrhage. Although the receptors mediating the effects of ET-1 human cerebrovasculature are well characterized, data concerning the functionally relevant ET-converting enzyme (ECE) activity are scarce. METHODS: ECE activity was determined in organ bath studies by the use of intraoperatively harvested human pial arteries. The level of ECE activity was analyzed by comparing the shift in the concentration effect curves obtained for ET-1 and its precursor, big ET-1. In addition, the presence of ECE-1alpha immunoreactivity was studied in human cerebral tissue. RESULTS: ECE-1alpha immunoreactivity was found, although not consistently, in human cerebral arteries and was restricted to the endothelium. In isolated pial arterial segments, ET-1 and big ET-1 induced concentration-related contractions with mean pD(2) values of 9.25 +/- 0.34 and 7.13 +/- 0.17, respectively, yielding a 123-fold shift of big ET-1 versus mature ET-1. Preincubation with phosphoramidon (10(-4) mol/L) resulted in a small yet significant inhibition of the contraction induced by big ET-1. CONCLUSION: The results of our study indicate the presence of functional ECE activity and ECE-1alpha immunoreactivity in human cerebral arteries. Furthermore, the data suggest the presence of ECE-like activity that differs from that of ECE-1alpha.     

Plasma endothelin and big endothelin concentrations and serum endothelin-converting enzyme activity following aneurysmal subarachnoid hemorrhage

OBJECT: Pathogenesis of delayed ischemia after aneurysmal subarachnoid hemorrhage (SAH) seems to be complex. An important mediator of chronic vasospasm may be endothelin (ET)-1 with its powerful and long-lasting vasoconstricting activity. In this prospective study the author investigated the correlations between serial plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 molar concentration ratio and serum endothelin-converting enzyme (ECE)-1 activity, and ischemic complications after SAH. METHODS: To measure plasma ET-1 (51 patients), big ET-1 immunoreactivity (22 patients), and serum ECE-1 activity (13 patients), blood samples were obtained on admission, in the morning after aneurysm surgery, and during the 2nd week after hemorrhage in 51 consecutive patients (28 men and 23 women, with a mean age of 50.8 years) with aneurysmal SAH. Mean plasma concentrations of ET-1 in patients with SAH (mean +/- standard deviation: on admission, 4.2 +/- 2 pg/ml; after surgery, 4.3 +/- 2.2 pg/ml; and during the 2nd week after SAH, 3.7 +/- 1.9 pg/ml) differed from those in healthy volunteers (2.9 +/- 1.2 pg/ml; p < 0.01). Plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 ratio did not change significantly with elapsed time following SAH; however, serum ECE-1 activity during the 2nd week after SAH was higher in patients with SAH than that in controls (162 +/- 43 compared with 121 +/- 56 pg/ml, respectively; p = 0.028). Plasma ET-1 concentrations (p < 0.05) and the ET-1/big ET-1 ratios (p = 0.063) were higher but plasma big ET-1 concentrations were lower (p < 0.05) in patients who experienced symptomatic delayed cerebral ischemia, compared with other patients with SAH. In addition, in cases in which follow-up computerized tomography scans or magnetic resonance images demonstrated permanent ischemic lesions attributable to vasospasm, patients had higher ET-1 concentrations than did other patients with SAH. CONCLUSIONS: The plasma ET-1 concentration correlates with delayed cerebral ischemia after SAH, suggesting that an increased ET conversion rate in the endothelium predicts ischemic symptoms. Increased serum ECE-1 activity during the 2nd week may reflect the severity of endothelial injury to cerebral arteries.     

An (CA)n dinucleotide repeat polymorphism of the interleukin-6 (IL-6) gene is associated with metacarpal bone mineral density in hemodialysis patients

Genetic factors may play an important role in the pathogenesis of reduced bone mineral density (BMD). IL-6 is a multifunctional cytokine and a candidate gene for regulation of bone mineral density (BMD). The relationship between a microsatellite polymorphism of the IL-6 gene and metacarpal BMD in Japanese hemodialysis patients was examined. We selected 165 patients (96 males and 69 females) with a mean age of 62.0 +/- 13.7 years (mean +/- standard deviation (SD) in this study. They were dialyzed for an average of 75.8 +/- 60.8 months (mean +/- SD). The microsatellite polymorphism in the IL-6 gene was examined. According to the number of cytosine-adenine repeats, varying from 13 to 18, 6 alleles could be distinguished. Patients were categorized based on the presence or absence of the allele with 126 bp (i.e. 14 CA repeats) (allele A, all others allele O). The frequencies of IL-6 gene genotypes in hemodialysis patients were 16.4% for OO, 52.1% for AO and 31.5% for AA. The BMD score adjusted for age and body weight (Z score) in the AA genotype group (-0.93 +/- 1.17) was significantly lower than that in the OO (-0.09 +/- 1.42, mean +/- SD, p < 0.005) or AO group (-0.48 +/- 1.15, mean +/- SD, p < 0.01). Serum intact PTH in the OO genotype group (79.3 +/- 84.6) was lower than that in the AA (120.8 +/- 113.6, mean +/- SD, p 0.10) or AO group (132.1 +/- 106.5, mean +/- SD, p < 0.05). These results suggest that polymorphism of the IL-6 gene may be a useful marker for reduced BMD.     

Tumor necrosis factor-alpha gene G-308A polymorphism is a risk factor for the development of membranous glomerulonephritis

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is a major pro-inflammatory cytokine. Recently, the G-308A polymorphism of the TNF-alpha gene has been associated with modified gene expression and increased TNF-alpha production in the -308A allele. We evaluated its influence on the incidence and clinical course of membranous glomerulonephritis. METHODS: We studied 53 patients with biopsy-proven primary membranous glomerulonephritis followed up for 5.7 +/- 4.9 years. 100 volunteers were analyzed as controls. According to the slope of the curve of reciprocal serum creatinine against time, group A (slow progressors, n = 35) and group B (fast progressors, n = 18) were defined. TNF-alpha G-308A polymorphism was determined by polymerase chain reaction amplification. RESULTS: The frequency of the A-allele (associated with higher TNF-alpha levels) was significantly higher in patients than control subjects (patients: G-allele: 0.66, A-allele: 0.34; controls: G-allele 0.85, A-allele 0.15, p < 0.001). Similarly, the genotype distribution differed significantly between our study and control populations (patients: GG-genotype: 41.5%, GA: 49.1%, AA 9.4%; controls: GG: 71%, GA: 27%, AA 2%, p = 0.001). Age, renal function, proteinuria and blood pressure were similar at the time of renal biopsy between patients with different genotypes (NS). There was also a tendency towards an overpresentation of the A-allele in group B indicating a possible impact on the progression of membranous nephropathy, but a significance was not reached. Furthermore, no impact on renal survival in the Kaplan- Meier analysis was detected (NS). CONCLUSION: Our results suggest that TNF-alpha gene G-308A polymorphism is a risk factor for the development of membranous glomerulonephritis.     

Increased renal expression of monocyte chemoattractant protein-1 and osteopontin in ADPKD in rats.

BACKGROUND: Human autosomal-dominant polycystic kidney disease (ADPKD) is variable in the rate of deterioration of renal function, with end-stage renal disease (ESRD) occurring in only approximately 50% of affected individuals. Evidence suggests that interstitial inflammation may be important in the development of ESRD in ADPKD. Han:SPRD rats manifest ADPKD that resembles the human disease. Homozygous cystic (Cy/Cy) rats develop rapidly progressive PKD and die near age 3 weeks. Heterozygous (Cy/+) females develop slowly progressive PKD without evidence of renal dysfunction until the second year of life, whereas heterozygous (Cy/+) males develop more aggressive PKD with renal failure beginning by 8 to 12 weeks of age. METHODS: To examine the relationship between proinflammatory chemoattractants and the development of interstitial inflammation and ultimately renal failure in ADPKD, we evaluated monocyte chemoattractant protein-1 (MCP-1) and osteopontin mRNAs and proteins in kidneys from Han:SRPD rats. RESULTS: MCP-1 and osteopontin mRNAs, expressed at low levels in kidneys from normal (+/+) animals at all ages, were markedly elevated in kidneys from 3-week-old Cy/Cy animals. In kidneys from heterozygous (Cy/+) adults of either gender, MCP-1 and osteopontin mRNAs were more abundant than normal; MCP-1 mRNA was more abundant in Cy/+ males than in females. Thus, chemoattractant mRNA expression correlated with the development of renal failure in Cy/Cy and Cy/+ rats. Osteopontin mRNA, localized by in situ hybridization, was moderately expressed in the renal medulla of normal animals; however, this mRNA was expressed at very high levels in the cystic epithelia of Cy/+ and Cy/Cy animals. MCP-1 and osteopontin proteins, localized by immunohistochemistry, were weakly detected in +/+ kidneys but were densely expressed in Cy/Cy and in adult Cy/+ kidneys, primarily over cystic epithelium. Increased expression of chemoattractants was associated with the accumulation of ED-1 positive cells (macrophages) in the interstitium of cystic kidneys. CONCLUSIONS: We suggest that proinflammatory chemoattractants have a role in the development of interstitial inflammation and renal failure in ADPKD.     

Epidermal growth factor receptor polymorphism and autosomal dominant polycystic kidney disease

BACKGROUND: The clinical variability in the rate of progression of autosomal dominant polycystic kidney disease (ADPKD) has been attributed to genetic heterogeneity, though environmental factors and modifying genes very likely play an important role as well. We examined the association between clinical outcome, defined by age at onset of end-stage renal disease (ESRD) in 46 ADPKD patients, and a polymorphism in the epidermal growth factor receptor (EGFR) gene, a candidate modifying gene. EGFR is a key element in renal tubular proliferation. METHODS: This study comprised 46 unrelated patients with ADPKD and ESRD, and 58 healthy controls. The patients had prevalently PKD 1 mutations. The EGFR microsatellite polymorphism was genotyped according to Gebhardt et al (11). RESULTS: The allele frequencies of the EGFR polymorphism were different in the ADPKD sample and the control population (G2=17.19; P=0.009). In particular, the frequencies of the 122 and 118bp length alleles had a different distribution (P=0.010 and P=0.047 respectively). Patients with the 122bp length polymorphism had ESRD at an earlier age,but this finding was not statistically significant. CONCLUSIONS: These findings suggest an association between the EGFR microsatellite polymorphism and ADPKD. However, it is difficult to establish which alleles are protective and which harmful. A larger, multicenter study may help clarify these results and is also required to replicate our preliminary finding of an association between ADPKD and the EGFR polymorphism.     

Klotho G-395A基因多态性与ESRD患者钙磷代谢紊乱的相关性分析

目的观察终末期肾病(ESRD)患者klotho G-395A基因多态性分布与其合并钙磷代谢紊乱的相关性。 方法选取2015年4月至2016年12月期间就诊于扬州市多个血液净化中心的ESRD患者共137例,体检中心正常体检者80名为对照组;运用FQ-PCR(TaqMan法)对各研究对象进行klotho基因G-395A多态性分型;检测klotho蛋白、成纤维细胞生长因子(FGF23)及钙磷代谢相关生化指标水平,比较不同基因型间各生化指标间的水平。卡方检验、t检验、单因素方差分析、Mann-Whitney U检验及Kruskal-Wallis H检验用于各组生化指标间差异性分析,多因素采用二元logistic回归分析。 结果①ESRD组和健康对照组的基因型分布均符合Hardy-Weinberg平衡(χ²＝0.512, χ²＝0.134; P<0.05)。②ESRD组和对照组基因亚型及基因频率分布差异有统计学意义(χ² ＝11.467, P＝0.003; χ²＝10.130, P＝0.001),且ESRD组患者A等位基因频率较对照组高。③ESRD组不同的基因型中,血钙、klotho蛋白及FGF23水平差异有统计学意义(P<0.05),血钙在GA型与AA型间表达水平差异有统计学意义(t＝－2.469,P＝0.015), FGF23、klotho蛋白在GG与AA型(Z＝－4.020, Z＝－5.461; P<0.001),GA与AA型(Z＝－4.303, Z＝－5.610; P<0.001)之间的表达水平差异均有统计学意义。④二元logistic回归分析示GA＋AA型为ESRD患者钙磷代谢紊乱的独立危险因素。 结论Klotho G-395A基因多态性A等位基因位点可能为ESRD患者的易感基因,并与ESRD患者合并钙磷代谢紊乱有关。     

Anticipation of end stage renal disease in patients with autosomal dominant polycystic kidney disease in successive generations.

Autosomal dominant polycystic kidney disease is a disorder, which is inherited in 50% of offspring, irrelevant the sex and it has a variable clinical expressivity. Initially it was noticed that the clinical expression was interfamilial, but some studies found out that it was different. The aim of this study was to evaluate the age of onset of end-stage renal disease (ESRD) in affected parents in comparison with their offspring in successive generations. We studied 60 families of patients with autosomal dominant polycystic kidney disease (ADPKD). The diagnosis was done by echo criteria and we included only the patients for whom we knew precisely the onset of ESRD (affected parent and offspring), the sex of the parent who suffered from the disease, and offspring. We found out that the ESRD in ADPKD appears at the same age in affected parents and offspring (49,3 +/- 7,9 Vs 51,8 +/- 9,2, p = NS) irrelevant of the sex of the offspring. Patients with paternal inheritance (n = 38) were diagnosed to have ESRD earlier than their affected parents (47,9 +/- 8,3 Vs 52,2 +/- 9,2 p < 0,05), but patients with maternal inheritance had no difference (n = 22) (51,9 +/- 6,8 Vs 51,2 +/- 9,4, p = NS). In all the patients (60 couples) the survival rate was the same between affected parents and offspring (p = NS, Kaplan-Meier test), but significant differences were noticed between offspring with paternal inheritance in comparison with their parents (p < 0,05). In conclusion, we have detected that the onset of ESRD between patients with ADPKD in successive generations: a) Occurs in offspring as in their ancestors, b) anticipation was observed in 55% of couples, c) the sex of offspring does not have any relation with the renal death and d) the ESRD in patients with paternal inheritance occurs earlier in offspring than in their ancestors but not with maternal.