Mass spectrometry-based proteomic analysis of proteins adsorbed by hexadecyl-immobilized cellulose bead column for the treatment of dialysis-related amyloidosis.

BACKGROUND: Dialysis-related amyloidosis (DRA) is a severe complication in end-stage kidney disease (ESKD) patients undergoing long-term dialysis treatment, characterized by the deposition of ß2-microglobulin-related amyloids (Aß2M amyloid). To inhibit DRA progression, hexadecyl-immobilized cellulose bead (HICB) columns are employed to adsorb circulating ß2-microglobulin (ß2M). However, it is possible that the HICB also adsorbs other molecules involved in amyloidogenesis. METHODS: We enrolled 14 ESKD patients using HICB columns for DRA treatment; proteins were extracted from HICBs following treatment and identified using liquid chromatography-linked mass spectrometry. We measured the removal rate of these proteins and examined the effect of those molecules on Aß2M amyloid fibril formation in vitro. RESULTS: We identified 200 proteins adsorbed by HICBs. Of these, 21 were also detected in the amyloid deposits in the carpal tunnels of patients with DRA. After passing through the HICB column and hemodialyzer, the serum levels of proteins such as ß2M, lysozyme, angiogenin, complement factor D and matrix Gla protein were reduced. These proteins acted in the Aß2M amyloid fibril formation. CONCLUSIONS: HICBs adsorbed diverse proteins in ESKD patients with DRA, including those detected in amyloid lesions. Direct hemoperfusion utilizing HICBs may play a role in acting Aß2M amyloidogenesis by reducing the amyloid-related proteins.

Pruritus and protein-bound uremic toxins in patients undergoing hemodialysis: a cross-sectional study.

Background: Patients undergoing hemodialysis frequently experience pruritus; its severity is associated with poor quality of life and mortality. Recent progress in hemodialysis treatment has improved the removal of small- and middle-molecular-weight molecules; however, the removal of protein-bound uremic toxins (PBUTs) remains difficult. It is possible that pruritus is associated with serum PBUTs in patients undergoing hemodialysis. Methods: We conducted a multicenter cross-sectional study in patients undergoing hemodialysis (n = 135). The severity of pruritus was assessed using the 5D-itch scale and medication use. Serum PBUTs, including indoxyl sulfate, p-cresyl sulfate, indole acetic acid, phenyl sulfate, and hippuric acid, were measured using mass spectrometry; the PBUT score was calculated from these toxins using principal component analysis. Univariate and multiple regression analyses were performed to examine independent predictors of pruritus. Results: Pruritus was reported by 62.2%, 21.5%, and 13.3%, 1.5% and 0.7% as 5 (not at all), 6-10, 11-15, 16-20, and 21-25 points, respectively. The PBUT score was higher in patients undergoing dialysis having pruritus than those without pruritus (0.201 [-0.021 to 0.424] vs -0.120 [-0.326 to 0.087]; P = 0.046). The PBUT score was shown to have an association with the presence of pruritus (coefficient 0.498[Formula: see text]0.225, odds ratio: 1.65 [1.06-2.56]; P = 0.027). Conclusion: Uremic pruritus was frequently found and associated with the PBUT score in patients undergoing hemodialysis. Further studies are required to clarify the impact of PBUTs on uremic pruritus and to explore therapeutic strategies in patients undergoing hemodialysis.

Epigenetic Regulation of ALS and CMT: A Lesson from Drosophila Models.

Amyotrophic lateral sclerosis (ALS) is the third most common neurodegenerative disorder and is sometimes associated with frontotemporal dementia. Charcot-Marie-Tooth disease (CMT) is one of the most commonly inherited peripheral neuropathies causing the slow progression of sensory and distal muscle defects. Of note, the severity and progression of CMT symptoms markedly vary. The phenotypic heterogeneity of ALS and CMT suggests the existence of modifiers that determine disease characteristics. Epigenetic regulation of biological functions via gene expression without alterations in the DNA sequence may be an important factor. The methylation of DNA, noncoding RNA, and post-translational modification of histones are the major epigenetic mechanisms. Currently, Drosophila is emerging as a useful ALS and CMT model. In this review, we summarize recent studies linking ALS and CMT to epigenetic regulation with a strong emphasis on approaches using Drosophila models.

The Association between Earlobe Creases and Cardiovascular Events in Japanese Hemodialysis Patients: A Prospective Cohort Study.

Objective The earlobe crease, a wrinkle extending from the tragus to the outer border of the earlobe, is a well-known surrogate marker for a high risk of cardiovascular disease. However, information is lacking about its association with cardiovascular events among hemodialysis patients, who already have an increased risk of cardiovascular disease. We tested the hypothesis that earlobe creases are independently associated with the risk of cardiovascular events among Japanese hemodialysis patients. Methods This prospective cohort study followed 247 adult hemodialysis patients with no history of cardiovascular disease for 4 years. The presence of earlobe creases was defined by two researchers using photos of patients' earlobes on both sides while blinded to one another's assessments and clinical data. The primary outcome was defined as the first fatal or nonfatal cardiovascular event (myocardial infarction, ischemic or hemorrhagic stroke, or peripheral vascular disease requiring aortic or peripheral vascular bypass surgery or below- or above-the-knee amputation). A Fine-Gray competing risks regression model was used to examine the association between earlobe creases and cardiovascular events. Results During the 4-year follow-up period, 43 patients suffered cardiovascular events. After the competing risk of non-cardiovascular death was accounted for, patients with earlobe creases had an increased cumulative incidence of cardiovascular events compared to those without earlobe creases (subhazard ratio =2.04, 95% confidence interval: 1.09 to 3.82). This association was no longer significant after adjusting for age. Conclusion Earlobe creases were not independently associated with cardiovascular events among Japanese hemodialysis patients, suggesting that these marks are simply indicative of advanced age.

Adsorption of Protein-Bound Uremic Toxins Through Direct Hemoperfusion With Hexadecyl-Immobilized Cellulose Beads in Patients Undergoing Hemodialysis.

An accumulation of protein-bound uremic toxins (PBUTs) is one of major reasons for development of uremia-related complications. We examined the PBUT removal ability of a hexadecyl-immobilized cellulose bead (HICB)-containing column for patients undergoing hemodialysis. Adsorption of indoxyl sulfate (IS), a representative PBUT, to HICBs was examined in vitro. The HICB column was used in patients undergoing hemodialysis for direct hemoperfusion with a regular hemodialyzer. The serum IS, indole acetic acid (IAA), phenyl sulfate (PhS), and p-cresyl sulfate (PCS) levels were measured before and after passing the column. HICBs adsorbed protein-free (free) IS in a dose- and time-dependent manner in vitro (55.4 ± 1.4% adsorption of 1 millimolar, 251 µg/mL, IS for 1 h). In clinical studies, passing the HICB-containing column decreased the serum level of free IS, IAA, PhS, and PCS levels significantly (by 34.4 ± 30.0%, 34.8 ± 25.4%, 28.4 ± 18.0%, and 34.9 ± 22.1%, respectively), but not protein-bound toxins in maintenance hemodialysis patients. HICBs absorbed some amount of free PBUTs, but the clinical trial to use HICB column did not show effect to reduce serum PBUTs level in hemodialysis patients. Adsorption treatment by means of direct hemoperfusion with regular hemodialysis may become an attractive blood purification treatment to increase PBUT removal when more effective materials to adsorb PBUTs selectively will be developed.

Prevalence of Earlobe Creases and Their Association With History of Cardiovascular Disease in Patients Undergoing Hemodialysis: A Cross-Sectional Study.

Earlobe creases are surrogate markers for high risk of cardiovascular disease. There is no data concerning earlobe creases among hemodialysis patients, who have an increased risk of cardiovascular disease. A cross-sectional study was conducted to determine the prevalence of earlobe creases and their association with prevalent cardiovascular disease among hemodialysis patients. Patients undergoing hemodialysis were recruited from five outpatient hemodialysis centers. Both earlobes were photographed during a dialysis session with the patient in a supine position and the photos evaluated independently by two experienced nephrologists blinded to the participants' clinical characteristics. Prevalent cardiovascular diseases were defined as a history of myocardial infarction, cerebrovascular accident, or peripheral vascular disease. Sensitivity, specificity, and positive and negative predictive values for detection of prevalent cardiovascular disease were calculated. Logistic analysis was used to examine the association between earlobe creases and prevalent cardiovascular disease. Earlobe creases were identified in 24.5% of 330 hemodialysis patients (200 men; mean age, 67.8 years). The prevalence of earlobe creases increased with age for men (P for trend <0.0001), but not for women (P for trend = 0.07). Sensitivity, specificity, and positive and negative predictive values were 30.9% (95% confidence interval, 21.9-41.6), 77.5% (71.9-82.3), 30.9% (21.9-41.6), and 77.5% (71.9-82.3), respectively. Multivariate logistic analyses indicated the prevalence of earlobe crease was not associated with prevalent cardiovascular diseases. The prevalence is similar to that previously reported for Japanese individuals not undergoing dialysis. No association between earlobe creases and prevalent cardiovascular diseases was identified.

Continuous Reduction of Protein-Bound Uraemic Toxins with Improved Oxidative Stress by Using the Oral Charcoal Adsorbent AST-120 in Haemodialysis Patients.

Accumulation of protein-bound uraemic toxins (PBUTs) is one of the reasons for the development of uraemia-related complications including cardiovascular disease; however, conventional haemodialysis is limited in its ability to remove PBUTs. We aimed to examine whether the oral charcoal adsorbent AST-120 has an additive effect on PBUT removal in haemodialysis patients. During the 4-week study, anuric patients undergoing haemodialysis received AST-120 (6 g/day) in the last 2 weeks (n = 10) or the first 2 weeks (n = 10). Serum levels of total and free PBUTs such as indoxyl sulfate, p-cresyl sulfate, and phenyl sulfate at the pre- and postdialysis sessions were measured before and after AST-120 use and after discontinuation. Levels of the oxidative stress markers oxidized albumin and 8-isoprostane were also measured. AST-120 use induced dramatic reduction of indoxyl sulfate (total, 45.7% [33.2-50.5%]; free, 70.4% [44.8-79.8%]), p-cresyl sulfate (total, 31.1% [25.0-48.0%]; free, 63.5% [49.3-70.9%]), and phenyl sulfate (free, 50.6% [32.3-71.2%]) levels; however, this effect disappeared after the discontinuation of AST-120. AST-120 use also induced substantial reduction of the oxidized albumin and 8-isoprostane levels. In conclusion, oral administration of AST-120 had additive effects on the continuous reduction of some PBUTs in anuric patients undergoing haemodialysis.

Uremic pruritus in chronic hemodialysis patients.

Skin itching (pruritus) affects 50%-90% of patients undergoing peritoneal dialysis or hemodialysis and the symptoms range from localized and mild to generalized and severe. Among the dermatological abnormalities associated with end-stage renal disease, pruritus is the most prevalent. Of all systemic disorders, uremia is the most important cause of pruritus. The mechanism underlying uremic pruritus is poorly understood: secondary hyperparathyroidism, divalent-ion abnormalities, histamine, allergic sensitization, proliferation of skin mast cells, iron-deficiency anemia, neuropathy and neurological changes, or a combination of these have been hypothesized. Severe pruritus not only affects the quality of life but is also associated with poor outcome in chronic hemodialysis patients. No specific, effective treatment is currently available for uremic pruritus. Further studies are necessary to evaluate the long-term efficacy and safety of a novel kappa-opioid agonist, nalfurafine. Early diagnosis and treatment of uremic pruritus focusing on general strategies that include the optimization of dialysis dose, erythropoiesis-stimulating agents, and management of secondary hyperparathyroidism is recommended.

Mortality predictors after 10 years of dialysis: a prospective study of Japanese hemodialysis patients.

BACKGROUND: This work aimed to examine the predictive value for death of various clinical variables after long-term hemodialysis (HD). DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: A total of 947 patients (597 men and 350 women, aged 21 to 93 yr) who were undergoing maintenance HD in Niigata, Japan, were stratified into two cohorts: Those with >10 yr of prior HD at study enrollment (n = 391) and those with < or =10 yr of previous therapy (n = 556). The survival of patients was examined for up to 40 mo (1999 to 2003) with the Cox proportional hazards model. Baseline clinical and dialysis data and serum biochemistries were used as independent variables. For adjustment for bias in patient selection, patient survival in either cohort was analyzed separately. RESULTS: In patients with >10 yr of HD, high pulse pressure, cerebrovascular disease, low serum creatinine, and low Kt/V values were the mortality risk predictors, whereas for those with < or =10 yr of HD, age and cerebrovascular disease were independent risk predictors for death. Diabetes, coronary artery disease, serum albumin, and C-reactive protein were NS predictors in those with long-term HD. CONCLUSIONS: Providing adequate dosage of dialysis and achieving a better control of pulse pressure may further improve survival in selected patients who had undergone HD for >10 yr.

Circulating osteoprotegerin affects bone metabolism in dialysis patients with mild secondary hyperparathyroidism.

Osteoprotegerin (OPG) is a soluble glycoprotein which inhibits osteoclastic formation and activity. Circulating OPG levels are elevated in uremia. The role of elevated circulating OPG levels in uremia remains unknown. Blood samples were obtained from 22 non-diabetic dialysis patients who underwent iliac bone biopsy examination. The serum OPG concentration was assayed by ELISA. The circulating OPG levels showed a negative correlation with the ratio of eroded surface/bone surface (ES/BS) in biopsied iliac bone samples among 15 of those with plasma intact PTH levels less than 300 pg/mL (P < 0.05, r(2) = 0.270). Patients with serum OPG levels less than 2.0 ng/mL showed significantly greater ES/BS values than those with levels > or =3.0 ng/mL, while the intact PTH levels were comparable among those groups. These tendencies disappeared when seven patients with plasma intact PTH levels more than 300 pg/mL were included into the analysis. In conclusion, circulating OPG levels showed a significant negative correlation with a bone resorption parameters in dialysis patients with mild secondary hyperparathyroidism. Circulating OPG might have a suppressive effect on osteoclastic bone resorption in dialysis patients.

Pretreatment plasma intact parathyroid hormone and serum calcium levels, but not serum phosphate levels, predict the response to maxacalcitol therapy in dialysis patients with secondary hyperparathyroidism.

BACKGROUND: The treatment strategy for secondary hyperparathyroidism is generally determined empirically with regards to present parathyroid function and serum calcium (Ca) and inorganic phosphate (Pi) levels. More evidence is needed to avoid the aimless continuation of active vitamin D therapy. METHODS: Nondiabetic dialysis patients whose plasma intact parathyroid hormone (iPTH) levels were greater than 300 pg/ml were included in the study. Maxacalcitol was intravenously injected three times a week. The treatment was continued for 48 weeks, unless the iPTH level was reduced to less than 300 pg/ml or unfavorable events occurred. The patients whose plasma iPTH levels were below 300 pg/ml within 48 weeks were defined as those who had been successfully treated. RESULTS: Findings for 146 patients were analyzed, and 96 patients were successfully treated. Serum Pi levels did not significantly increase during the therapy. The pretreatment plasma iPTH levels and serum Ca levels were lower in the patients who were successfully treated with maxacalcitol. A logistic regression study and classifying by stratum analyses revealed that the pretreatment serum Ca levels and plasma iPTH levels were significantly related to the result of maxacalcitol therapy, while the serum Pi levels were not. Analyses using a receiver-operating characteristic curve revealed that the areas under curves obtained for iPTH and Ca were significantly greater than those obtained for Pi (P < 0.0001). CONCLUSIONS: Serum Ca levels and parathyroid function were correlated with the results of maxacalcitol therapy. Pretreatment serum Pi levels could not predict the result.

Pretreatment serum FGF-23 levels predict the efficacy of calcitriol therapy in dialysis patients.

BACKGROUND: The predictor for the result of calcitriol therapy would be useful in the clinical practice of secondary hyperparathyroidism. Fibroblast growth factor-23 (FGF-23) is a newly found circulating phosphaturic factor. Its circulating level is elevated in uremia. METHODS: Dialysis patients with plasma intact parathyroid hormone (iPTH) levels greater than 300 pg/mL were included in the study. Calcitriol was intravenously injected three times a week. The patients whose plasma iPTH levels dropped below 300 pg/mL within 24 weeks were defined as those who had been successfully treated. A sandwich enzyme-linked immunosorbent assay (ELISA) system that detects human FGF-23 was applied. RESULTS: Sixty-two patients were analyzed. The pretreatment FGF-23 levels were related to the iPTH levels, calcium x phosphate product levels, and history of active vitamin D therapy. The pretreatment FGF-23, iPTH, and calcium levels were lower in the patients who would be successfully treated with calcitriol. A logistic regression study revealed that the pretreatment iPTH and FGF-23 levels significantly affected the therapy results. Analyses using a receiver-operated curve revealed that FGF-23 was the best screening test for identifying patients with future refractory response to calcitriol therapy. The treatment would be successful in 88.2% of those with FGF-23 9860 ng/L and iPTH >591 pg/mL. CONCLUSION: Pretreatment serum FGF-23 levels were a good indicator in predicting the response to calcitriol therapy. The measurement of serum FGF-23 levels, especially in combination with iPTH levels, is a promising laboratory examination for the clinical practice of secondary hyperparathyroidism.

Serum fibroblast growth factor-23 levels predict the future refractory hyperparathyroidism in dialysis patients.

BACKGROUND: Secondary hyperparathyroidism is a common complication among long-term dialysis patients. The method of predicting future parathyroid function has not yet been established. Fibroblast growth factor-23 (FGF-23) is a newly found humoral phosphaturic factor. METHODS: One hundred and three nondiabetic dialysis patients whose plasma intact parathyroid hormone (PTH) levels were below 300 pg/mL were included in the study. Blood samples were stored at -80 degrees C for 2 years. Meanwhile, each physician in charge decided upon the strategy of medical therapy for maintaining intact PTH levels between 150 and 300 pg/mL. Patients were judged 2 years after the sample collection with regard to whether the hyperparathyroidism responded to the medical therapy. The definition of refractory secondary hyperparathyroidism was either (1) retaining intact PTH levels greater than 300 pg/mL 2 years after sample collection, or (2) having received the parathyroid intervention therapy during the observation period. Serum FGF-23 levels were determined with a sandwich enzyme-linked immunosorbent assay system that detects biologically active human FGF-23. RESULTS: Seventeen patients with intact PTH levels greater than 300 pg/mL were judged as having secondary hyperparathyroidism refractory to medical therapy. A stepwise regression analysis revealed that only serum levels of FGF-23 were significantly related to the prognosis of parathyroid function. A receiver-operated characteristic analysis demonstrated that the area under the curves obtained from FGF-23 (7099.9) was significantly greater than that obtained from intact PTH (6306.4, P < .01) and Ca x Pi (5670.3, P <.0001). Although the plasma intact PTH levels at the beginning of the observation period were comparable to each other, the intact PTH levels at 2 years after the sample collection were significantly higher in the patients with FGF-23 >/=7500 ng/L than in those with FGF-23 <7500 ng/L (P < .0001). CONCLUSION: Serum FGF-23 level was found to be the most useful factor in predicting future development of refractory secondary hyperparathyroidism in long-term dialysis patients with mild secondary hyperparathyroidism. The measurement of serum FGF-23 levels is a promising laboratory examination that can be applied in the clinical practice of uremic secondary hyperparathyroidism.

Intact PTH assay overestimates true 1-84 PTH levels after maxacalcitol therapy in dialysis patients with secondary hyperparathyroidism.

BACKGROUND: Although the so-called intact parathyroid hormone (iPTH) assay detects not only true 1-84 PTH (1-84PTH) but also large C-terminal PTH fragments, it remains inconclusive whether the 1-84PTH assay is more useful in clinical practice. Previous studies have shown that the results of these two PTH assays in dialysis patients are closely correlated. METHODS: Chronic dialysis patients whose plasma iPTH levels were >400 pg/ml were selected for inclusion in the present study. Following a 4 week wash-out time during which all vitamin D administration was halted, maxacalcitol was intravenously injected at the end of dialysis sessions three times per week for 24 weeks, at an initial dosage of 10 micro g. RESULTS: Ninety-seven patients with secondary hyperparathyroidism were included in our analysis. Their serum calcium levels were elevated from the start levels while phosphate levels remained unchanged. The plasma 1-84PTH levels constantly declined throughout the 24 weeks. Although the patients' plasma 1-84PTH and iPTH levels were closely correlated with each other both at the beginning of the study and after 24 weeks of maxacalcitol therapy, the ratio of 1-84PTH/iPTH consistently decreased throughout the study period (P<0.01). The changes in the ratio were significantly correlated with changes in serum calcium levels. CONCLUSIONS: Twenty-four weeks of intravenous maxacalcitol injection therapy significantly reduced the 1-84PTH/iPTH ratio. Estimated 1-84PTH levels from iPTH levels using a conversion formula obtained before the treatment were 21.0+/-20.4% higher than measured 1-84PTH levels after the therapy. Thus, iPTH measurement has a potential risk to overestimate 1-84PTH levels when evaluating the efficacy of maxacalcitol therapy in dialysis patients with secondary hyperparathyroidism.

Genetic polymorphism of NPHS1 modifies the clinical manifestations of Ig A nephropathy.

Nephrin, the molecule responsible for congenital nephrotic syndrome of Finnish type, is crucial in maintaining the glomerular filtration barrier. Recently, its complete gene structure and common gene polymorphisms in its exons have been reported, although the functional and clinical significance of these polymorphisms has not yet been elucidated. We investigated a possible association of the NPHS1 polymorphisms with the development of Ig A nephropathy (IgAN), as well as the clinical and histologic manifestations in IgAN. A total of 464 Japanese subjects, including 267 patients with histologically proven IgAN and 197 healthy controls with normal urinalysis, were genotyped for the NPHS1 G349A, G2289A, and T3315C polymorphisms. The frequencies of the genotypes, alleles, and estimated haplotypes of NPHS1 polymorphisms were no different between patients with IgAN and the controls. Within the IgAN group, patients carrying at least one G allele of G349A tended to present with more proteinuria, lower renal function, and more severe histopathologic injury than those with the AA genotype, although the time from the first urinary abnormality to the renal biopsy was no different between both groups. The logistic regression analysis indicated that even after adjusting for the effect of proteinuria and hypertension the GG genotype of NPHS1 G349A was an independent risk factor for the deteriorated renal function at the time of diagnosis. This study suggests that the NPHS1 G349A polymorphism may be associated with heavy proteinuria and a decline in renal function in patients with IgAN.

Angiotensinogen gene variation and renoprotective efficacy of renin-angiotensin system blockade in IgA nephropathy.

BACKGROUND: Blockade of the renin-angiotensin system (RAS) is well documented to be renoprotective; however, not all patients with glomerulonephritis respond well to this therapy. The interindividual variation in response to the RAS blockade may be in part genetically determined, whereas the results have been controversial. METHODS: We investigated whether the therapeutic efficacy of angiotensin-converting enzyme (ACE) inhibitors and/or angiotensin receptor blocker on renal prognosis is modified by the angiotensinogen gene (AGT) polymorphism in immunoglobulin A nephropathy (IgAN). In total, 259 patients with histologically proven IgAN were analyzed for clinical manifestations, renal survival, and their associations with AGT A(-20)C and M235T. RESULTS: The renal prognosis of 110 patients, who received ACE inhibitors/angiotensin receptor blocker during their clinical course, was significantly better than those without ACE inhibitors/angiotensin receptor blockers despite higher blood pressures and heavier proteinuria. The Cox proportional hazards regression model showed an increased hazard ratio (HR) for urinary protein (more than 1.0 g/day) of 3.346 (P = 0.0001), hypertension of 1.949 (P = 0.01), deteriorated renal function of 3.040 (P < 0.0001), no ACE inhibitor/angiotensin receptor blocker administration of 2.725 (P = 0.0004), and the T235 and C(-20) haplotype of 1.608 (P = 0.0322). Only in patients carrying at least one M235 and A(-20) haplotype did the administration of ACE inhibitors/angiotensin receptor blockers have no significant effect on the prognosis of renal function (Kaplan-Meier, log rank test, chi2 = 0.700; P = 0.4028), whereas it was significant in patients who had other haplotypes of AGT (chi2 = 11.805; P = 0.0006). CONCLUSION: This study provides evidence that the M235T and A(-20)C genotype of AGT can influence the therapeutic efficacy of a RAS blockade on the renal survival in IgAN.

Vascular endothelial growth factor gene polymorphisms in Japanese patients with sarcoidosis.

OBJECTIVES: Vascular endothelial growth factor (VEGF) promotes angiogenesis, mediates vascular permeability, and activates and recruits monocytes. VEGF is produced in activated alveolar macrophages, in epithelioid cells, and in multinuclear giant cells of pulmonary sarcoid granulomas. Recent reports have shown that a polymorphism at - 627 of the VEGF gene is related to VEGF protein production, and a polymorphism at + 813 is associated with VEGF plasma levels. We investigated the roles of such polymorphisms in the development and extent of sarcoidosis. METHODS: We examined polymorphisms of the VEGF gene in 103 Japanese patients with sarcoidosis and 146 healthy Japanese control subjects. The position - 627 polymorphism was determined using the TaqMan (TaqMan Laboratory, University of Pittsburgh Cancer Institute; Pittsburgh, PA) polymerase chain reaction (PCR) method. For genotyping of the position + 813 polymorphism, the PCR restriction fragment length polymorphism method was performed. RESULTS: As for + 813 genotypes, the less-common genotypes CT and TT were found more often in control subjects than in patients (odds ratio, 0.490; 95% confidence interval, 0.276 to 0.868). A significant increase in the frequency of the T allele (p = 0.005, Pc = 0.020 after Bonferroni correction) was observed in control subjects. As for - 627 genotypes, the mean value of the FEV(1)/FVC percentage in GG type was lower than that in CC or CG type, however, the other clinical findings did not suggest airway diseases in the GG type. CONCLUSIONS: We suggest that in VEGF gene polymorphisms the T allele at + 813 may decrease susceptibility to sarcoidosis.

Role of genetic polymorphism in the SA gene on the blood pressure and prognosis of renal function in patients with immunoglobulin A nephropathy.

The SA gene has been shown to be much more highly expressed in the kidneys of spontaneously hypertensive rats than in the corresponding wild-type strain. Genetic polymorphism of this gene has been shown to play a role in human hypertension, although the details of this association remain controversial. We investigated the possible associations between SA gene polymorphism and both hypertension and the prognosis of renal function in patients with immunoglobulin A nephropathy (IgAN). Genomic DNA was isolated from the peripheral blood of 367 individuals, including 274 patients with histologically proven IgAN and 100 controls without any history of renal disease. The SA genotype was determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) with Pst I. The frequencies of genotypes and alleles were not different between the patients with IgAN and those without renal disease. In the group without renal disease, the SA gene polymorphism was not associated with hypertension. However, in the patients with IgAN the A1 allele frequency was significantly higher in the hypertensives than in the normotensives. The renal survival of the patients with the A2 allele tended to be better than that of those without the A2 allele. The findings thus suggest that SA gene polymorphism may be associated with the renal prognosis of IgAN through its effect on blood pressure. Further, they suggest that the sensitivity to this gene polymorphism increases in patients with renal injury.

MCP-1 and MIP-1A gene polymorphisms in Japanese patients with sarcoidosis.

OBJECTIVES: Monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha exhibit chemotactic activity toward macrophages/monocytes and induce the production of inflammatory cytokines affecting granuloma formation. Recently, a single nucleotide polymorphism (SNP) in the MCP-1 distal regulatory region and a dinucleotide repeat in the MIP-1A gene promoter region were identified. We investigated the relationships between the polymorphisms and susceptibility to sarcoidosis, clinical manifestations, and BALF findings of sarcoidosis. METHODS: The polymorphisms of the MCP-1 and MIP-1A genes in 118 patients with sarcoidosis and 145 healthy control subjects were examined. The MCP-1 polymorphism was genotyped by a PCR-restriction fragment length polymorphism method and the MIP-1A genotype was determined using PCR. RESULTS: No significant difference in the genotype distribution or in the allele frequency between the patients and control subjects was observed. We found no relationship between the polymorphisms and the serum ACE level, organ involvement, roentgenographic stages, or deterioration in chest radiographs during the follow-up. A significant difference in the absolute counts of AMs in BALF of 51 patients among the genotypes of the MCP-1 gene was found (p = 0.048). The AM counts in BALF of the G/A and G/G genotypes were significantly increased compared with that of the A/A genotype (p < 0.05). CONCLUSION: The polymorphisms of the MCP-1 and MIP-1A genes do not play a substantial role in genetic predisposition for sarcoidosis or in clinical manifestations of sarcoidosis in this Japanese population. The MCP-1 SNP might be related to the recruitment of monocytes/macrophages to the alveolar spaces in sarcoidosis.