Multicentre Study on the Efficacy of Brachial Artery Transposition Among Haemodialysis Patients.

OBJECTIVE: Brachial artery transposition (BAT) is not a well known method for obtaining vascular access (VA) for maintenance haemodialysis. This study evaluated the outcomes of BAT. METHODS: This multicentre retrospective cohort study included 233 consecutive patients who underwent BAT between January 2012 and December 2013. The indications were inadequate vessels for obtaining VA, severe heart failure, hand ischaemia, central vein stenosis/occlusion, or a history of catheter/graft infection. The transposed brachial artery was used only for arterial inflow and other routes were used for outflow. RESULTS: BAT was successful in 227 patients, and adequate blood flow was achieved during dialysis sessions. The first successful cannulation was after a median of 18 days. BAT was performed using superficial veins as the return route in 127 patients and arteriovenous fistula (AVF) creation in 63 patients to prevent maturation failure. In 41 patients with central venous catheterisation, the transposed brachial artery was used for arterial inflow. The complications of BAT were impaired wound healing in 14 patients, including skin necrosis in two; large aneurysms in six, including a mycotic pseudo-aneurysm in one; arterial thrombosis in five; hand ischaemia in five; lymphorrhoea in four; and haematoma/bleeding in three. The transposed brachial artery was abandoned in four, three, three, and one case of arterial thrombosis/stenosis, haematoma/bleeding, skin necrosis, and large aneurysm, respectively. Access to the return routes failed in 48 cases because of vein damage caused by cannulation in 22, AVF thrombosis/stenosis in 14, catheter infection in six, and catheter occlusion in six. At two years, the primary patency rates of the transposed brachial artery and access circuit were 88% and 54%, respectively. CONCLUSION: BAT is a safe and effective technique. The patency was high for the transposed brachial artery but adequate for the access circuit. BAT can be considered for patients with an unobtainable standard arteriovenous access.

Fistula and Survival Outcomes after Fistula Creation among Predialysis Chronic Kidney Disease Stage 5 Patients.

BACKGROUND: Most guidelines recommend the creation of arteriovenous fistula (AVF) in patients with chronic kidney disease (CKD) stage 4. However, an increasing number of studies suggest that early AVF creation leads to high rates of AVF failure and death before dialysis commencement. Only the Japanese guideline recommends AVF creation at CKD stage 5; however, no data are available regarding access-related outcomes at this stage. METHOD: This was a multicenter cohort study involving Japanese CKD stage 5 patients who underwent preemptive AVF creation from 2009 to 2013. The primary outcome was unnecessary AVF creation, defined as death before requiring dialysis or AVF failure before dialysis commencement. The secondary outcome was dialysis commencement. The associations with candidate predictors and the outcomes were examined. RESULTS: A total of 303 patients were registered. Four cases of death before dialysis and 13 cases of AVF failure before dialysis commencement were observed. A total of 283 patients who advanced to dialysis were found to have functional AVFs. The cumulative incidences of unnecessary AVF creation and dialysis commencement at 1 year were 4.8 and 89.3%, respectively. Competing risk regression analyses showed that age ≥75 years (subhazard ratio [SHR] 3.12, 95% CI 1.20-8.09) and female gender (SHR 3.31, 95% CI 1.20-9.09) were associated with unnecessary AVF creation. CONCLUSIONS: A low incidence of unnecessary AVF creation was revealed among Japanese patients who received AVF at CKD stage 5. These results may help clarify the natural history of unnecessary AVF creation for other countries reformatting their guidelines regarding late vascular access creation.

Predicting loss of patency after forearm loop arteriovenous graft.

OBJECTIVE: Although arteriovenous grafts (AVGs) for dialysis access have been applied to patients who were poor candidates for an arteriovenous fistula, durability after AVGs has been clinically suboptimal. This retrospective study investigated whether forearm AVGs based on radial artery inflow would have superior patency to those with brachial artery inflow and evaluated the operative predictors for loss of patency after AVG. METHODS: This multicenter retrospective study included 156 upper limbs in 150 consecutive patients (50% male; age, 70.5 ± 12.8 years) who underwent forearm loop AVG formation from January 2010 to October 2013. The outcome measures were the primary and secondary functional graft patency rates and factors related to primary patency. Primary and secondary patency of AVGs was evaluated by Kaplan-Meier analysis, and predictors for loss of primary patency of AVGs were determined using a Cox proportional hazards model. RESULTS: The median observation period was 10 months (interquartile range, 6-18 months). The 1-year primary patency rate was 32.4%, and the secondary patency rate was 83.4%. Use of the radial artery as the inflow arteriovenous anastomosis (hazard ratio, 0.56; 95% confidence interval, 0.30-0.99) was independently associated as an operative predictor for primary patency after AVG. The primary patency rate was significantly different between radial artery inflow and brachial artery inflow at 1 year (53.8% vs 24.4%; P = .032). CONCLUSIONS: Radial artery selection as inflow artery was independently associated with primary patency after AVG.

Coformulation of a Novel Human α-Galactosidase A With the Pharmacological Chaperone AT1001 Leads to Improved Substrate Reduction in Fabry Mice.

Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the gene that encodes α-galactosidase A and is characterized by pathological accumulation of globotriaosylceramide and globotriaosylsphingosine. Earlier, the authors demonstrated that oral coadministration of the pharmacological chaperone AT1001 (migalastat HCl; 1-deoxygalactonojirimycin HCl) prior to intravenous administration of enzyme replacement therapy improved the pharmacological properties of the enzyme. In this study, the authors investigated the effects of coformulating AT1001 with a proprietary recombinant human α-galactosidase A (ATB100) into a single intravenous formulation. AT1001 increased the physical stability and reduced aggregation of ATB100 at neutral pH in vitro, and increased the potency for ATB100-mediated globotriaosylceramide reduction in cultured Fabry fibroblasts. In Fabry mice, AT1001 coformulation increased the total exposure of active enzyme, and increased ATB100 levels in cardiomyocytes, cardiac vascular endothelial cells, renal distal tubular epithelial cells, and glomerular cells, cell types that do not show substantial uptake with enzyme replacement therapy alone. Notably, AT1001 coformulation also leads to greater tissue globotriaosylceramide reduction when compared with ATB100 alone, which was positively correlated with reductions in plasma globotriaosylsphingosine. Collectively, these data indicate that intravenous administration of ATB100 coformulated with AT1001 may provide an improved therapy for Fabry disease and thus warrants further investigation.

The first case report of peritoneal dialysis related peritonitis caused by Microbacterium paraoxydans.

Peritonitis is still the major complication associated with peritoneal dialysis (PD). Microbacterium spp., a type of coryneform bacteria, is an environmental bacterium isolated from soil, waste water and animals. Human infection is rare, and only few cases have so far been reported in immunocompromised hosts, such as PD patients. Microbacterium paraoxydans, one type of Microbacterium spp. was identified for the first time in 2003. Only two cases of infection of Microbacterium paraoxydans have so far been reported. We herein report the first case of PD-related peritonitis caused by Microbacterium paraoxydans, which was identified by a sequence determination of the 16S rRNA gene. Based on the results of antibiotic sensitivity, the intravenous administration of erythromycin (EM) and oral administration of sulfamethoxazole/trimethoprim (ST) were selected, and PD was interrupted. EM administration was stopped after a total of 14 days. ST was administered for a total of 21 days, and later PD was resumed. Thereafter, no recurrence or relapse of peritonitis without removal of the PD catheter was observed. Microbacterium spp. exhibits multidrug resistance and such an infection is refractory in many cases. We assume that both accurate species identification and the use of antibiotic sensitivity tests are essential to effectively treat this kind of infection.

Risk factors associated with inadequate veins for placement of arteriovenous fistulas for hemodialysis.

An arteriovenous fistula (AVF) between the radial artery and cephalic vein at the wrist is the preferred type of hemodialysis vascular access. However, in the practice of access placement, we are aware that some patients fail to form the standard forearm radial-cephalic AVF, owing to naturally small veins or acquired abnormal lesions of the veins. To identify the risk factors for failure to form the standard AVF, we examined 305 consecutive patients who underwent first-time access surgery at our hospital from January 2006 to December 2010. We compared the patients' characteristics between those having normal vessels and successfully forming the standard AVF, and those having apparently abnormal vessels and thus forming alternative types of access instead. Histories of major and minor surgery were specifically evaluated, assuming that surgical procedures in the past could potentially damage the superficial veins. We created 207 standard and 98 alternative accesses during the period and found that significantly more patients with alternative accesses (31 %) had undergone major surgery of a variety of specialties, in comparison with those with the standard AVF (15.0 %). Multivariate logistic analysis revealed that a history of major surgery (OR = 2.39, 95 %CI 1.29-4.47, p = 0.006) and female gender (OR = 1.87, 95 %CI 1.10-3.20, p = 0.02) were independent risk factors associated with failure to construct the standard AVF. Our results indicate that previous surgery can damage the superficial veins and cause venous abnormality, which makes construction of the standard AVF difficult. We propose that care should be taken to preserve the superficial veins when patients for whom dialysis therapy is a future possibility undergo surgical procedures, especially invasive ones.

Comparison of human glomerulus proteomic profiles obtained from low quantities of samples by different mass spectrometry with the comprehensive database.

BACKGROUND: We have previously constructed an in-depth human glomerulus proteome database from a large amount of sample for understanding renal disease pathogenesis and aiding the biomarker exploration. However, it is usually a challenge for clinical research to get enough tissues for large-scale proteomic characterization. Therefore, in this study, we focused on high-confidence proteomics analysis on small amounts of human glomeruli comparable to those obtained from biopsies using different mass spectrometers and compared these results to the comprehensive database. RESULTS: One microgram of human glomerular protein digest was analyzed each on five LC- combined mass spectrometers (LIT-TOF, LTQ-Orbitrap, Q-TOF, LIT and MALDI-TOF/TOF) yielding 139, 185, 94, 255 and 108 proteins respectively identified with strict criteria to ensure high confidence (> 99%) and low false discovery rate (FDR) (< 1%). An integrated profile of 332 distinct glomerular proteins was subsequently generated without discerned bias due to protein physicochemical properties (pI and MW), of which around 60% were detected commonly by more than two LC-MS/MS platforms. Comparative analysis with the comprehensive database demonstrated 14 proteins uniquely identified in this study and more than 70% of identified proteins in small datasets were concentrated to the top abundant 500 in the comprehensive database which consists of 2775 non-redundant proteins. CONCLUSION: This study showed representative human glomerulus proteomic profiles obtained from biopsies through analysis of comparable amounts of samples by different mass spectrometry. Our results implicated that high abundant proteins are more likely to be reproducibly identified in multiple mass spectrometers runs and different mass spectrometers. Furthermore, many podocyte essential proteins such as nephrin, podocin, podocalyxin and synaptopodin were also identified from the small samples in this study. Bioinformatic enrichment analysis results extended our understanding of the major glomerular proteins about their subcellular distributions and functions. The present study indicated that the proteins localized in certain cellular compartments, such as actin cytoskeleton, mitochondrial matrix, cell surface, basolateral plasma membrane, contractile fiber, proteinaceous extracellular matrix and adherens junction, represent high abundant glomerular proteins and these subcellular structures are also highly significantly over-represented in the glomerulus compared to the whole human background.

Prothrombin fragment 1 + 2 (F1 + 2) in effluent is a useful marker for peritoneal permeability in peritoneal dialysis patients using neutral dialysate.

To clarify the influence of neutral dialysate (ND) on peritoneum, we examined changes in peritoneal permeability and in various markers of the coagulation and fibrinolytic system in effluent and the correlations between peritoneal permeability and those markers in peritoneal dialysis (PD) patients using ND. We evaluated 14 patients (8 men, 6 women; mean age: 58.6 +/- 12.0 years) who started PD using ND. The peritoneal equilibration test (PET) was performed to assess dialysate-to-plasma ratio for creatinine (D/P Cr) as peritoneal permeability. Coagulation markers [thrombin-antithrombin complex, fibrin monomer (FM), prothrombin fragment 1+2 (F1 + 2)] and fibrinolytic markers (fibrin degradation products, D-dimer) in effluent were also measured. At 2 years, FM in effluent was significantly lower (p = 0.006). The other markers and the D/P Cr did not change significantly. At the initiation of PD and at 2 years, D/P Cr was significantly correlated with F1 + 2 (r = 0.70 and 0.76 respectively, p < 0.01). Furthermore, multiple regression analysis showed that only F1 + 2 was correlated with D/P Cr at 2 years (r = 0.79, p = 0.004). These results suggest that ND has little influence on coagulation and fibrinolytic markers in effluent. In addition, F1 + 2 is a useful marker for peritoneal permeability in PD patients using ND.

Delamination of Acuseal early cannulation arteriovenous graft months after implantation.

Arteriovenous fistula is recommended, but arteriovenous graft is acceptable when a fistula is not possible. Acuseal is an early cannulation graft with a trilayer structure. Although primary patency rates of Acuseal appear to be similar to those of other standard grafts, few studies have investigated long-term results and complications. In our series, delamination of the wall structure occurred in 5.1% (6/115) by 21 months after Acuseal implantation. The causes could be divided into cannulation-related and cannulation-unrelated. Here, we describe the six cases in which delamination of the wall structure occurred in the medium term after Acuseal implantation.

Brachial-brachial autogenous arteriovenous fistula in a dialysis patient with Staphylococcus aureus bacteremia.

As the number of patients on hemodialysis increases, there will also be an increase in the number of patients with inadequate superficial veins for the creation of an autogenous arteriovenous fistula (AVF). In those patients, medical devices such as vascular prostheses or tunneled-cuffed catheters are necessary to maintain dialysis access. However, these devices are frequently associated with bacterial infection. We recently encountered a dialysis patient who underwent tunneled-cuffed catheter insertion because of the lack of usable superficial veins for autogenous access, and this patient subsequently developed catheter-related Staphylococcus aureus bacteremia with multiple metastatic infections. Despite immediate removal of the catheter, the infection persisted over an extended period, which was a condition precluding the further use of catheters or other prosthetic materials. To handle this situation, we utilized the deep brachial vein to construct an autogenous AVF. After ligating numerous branches, the vein was anastomosed to the brachial artery and then transposed to the subcutaneous space. The newly constructed autogenous AVF, which successfully kept the patient free from foreign materials, greatly contributed to the relief of persistent infection. Although the brachial vein is rarely used for AVF creation, we suggest that it can serve as an option to create an alternative AVF in a patient with inadequate superficial veins.

Identification and localization of novel genes preferentially expressed in human kidney glomerulus.

AIM: To find novel genes abundantly and preferentially expressed in human glomerulus, we constructed a glomerular cDNA library and verified the reliability of our database by comparison with the Stanford Microarray Database (SMD), followed by reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization (ISH). METHODS: RNA was extracted from normal human glomeruli, and the cDNA library was constructed by plasmid cloning. Out of 5 x 10(3) clones from the library, 91 UniGene clusters of more than three clones were identified as 'glomerular-abundant genes'. All these genes were referred to the SMD, and 18 genes were defined as 'glomerular preferential genes'. Four unknown genes -IFI27, CRHBP, FLJ10154 and SEMA5B- were selected for RT-PCR to compare expression in the glomerulus with that in the cortex and medulla, and for ISH to examine glomerular localization. Also, three unknown genes that were glomerular abundant but not listed in the SMD -DDX5, HSPC138, and MGC10940- were selected for RT-PCR and ISH. Finally, a kidney biopsy specimen of crescentic glomerulonephritis was used for ISH to examine glomerular expression for CRHBP mRNA. RESULTS: Among the selected seven glomerular-abundant genes, six were confirmed as 'glomerular preferential genes' by RT-PCR. By ISH, all these genes were demonstrated in podocytes. The expression of CRHBP mRNA in a single living podocyte was not changed between normal and crescentic glomerulus. CONCLUSION: Glomerular preferential expression and podocyte localization of these novel genes have been demonstrated for the first time. Because some of these genes were not listed in SMD, our database can be a useful tool to find novel human glomerular genes.

Systemic Inflammatory Response Syndrome Is Not an Indicator of Bacteremia in Hemodialysis Patients With Native Accesses: A Multicenter Study.

Bloodstream infection (BSI) in hemodialysis (HD) patients is often difficult to diagnose. Systemic inflammatory response syndrome (SIRS) is a sensitive predictor of BSI in the general population. We aimed to assess the usefulness of SIRS in predicting BSI in HD patients. We designed a multicenter retrospective observational study of adult (age > 18 years) HD patients who underwent two sets of blood cultures for suspected BSI at first hospital visit from August 2011 to July 2012. Clinical, biological, and microbial data were evaluated to evaluate SIRS as a predictor of BSI upon initial presentation to the hospital. Data were obtained from 279 HD patients. Vascular access other than arteriovenous fistula and subcutaneously fixed superficial artery, and those administered antimicrobial drugs before visit were excluded; thus, a total of 202 patients were finally enrolled. Mean patient age was 71 years, 67.3% were male, 49.3% had diabetes, 28.2% had indwelling hardware, and 18.3% patients had BSI. Endocarditis and vertebral osteomyelitis were common infection sites, and Staphylococcus aureus was the most common pathogen. Of those with SIRS, 25.3% had BSI and 74.7% did not (odds ratio for SIRS, 2.10; 95% confidence interval, 0.90-4.91; p = 0.11). Thus, SIRS had a low sensitivity for predicting BSI in HD patients (sensitivity, 71.9%; specificity, 45.2%; positive likelihood ratio, 1.31; negative likelihood ratio, 0.62). Systemic inflammatory response syndrome has low sensitivity in identifying BSI in HD patients. A low threshold for drawing blood cultures and initiating antibiotic treatment should be considered for HD patients.

Association Between Staphylococcus aureus Bacteremia and Hospital Mortality in Hemodialysis Patients With Bloodstream Infection: A Multicenter Cohort From Japanese Tertiary Care Centers.

Multiple studies have shown that Staphylococcus aureus bacteremia (SAB) has been a major cause of death in hemodialysis patients. We examined whether SAB is a risk for mortality among chronic hemodialysis patients in Japan where the standard vascular access is arteriovenous fistula (AVF). This was a multicenter, retrospective study of maintenance hemodialysis patients with bloodstream infection (BSI) from 2011 to 2013 at tertiary care centers in Japan. The endpoint was hospital mortality. Our cohort contained 32 SAB cases (14 MRSA and 18 MSSA) and 42 non-SAB cases. Hospital mortality was higher among SAB cases than non-SAB cases (46.9% vs. 23.8%, P = 0.038). In patients with BSI, SAB was significantly associated with hospital mortality after adjustment for potential confounders, including type of vascular access (OR 3.26). S. aureus was the leading cause of BSI and hospital mortality among this cohort. Therefore, initial empiric treatment should cover for S. aureus.

Percutaneous transluminal angioplasty in Japan: five-center investigation.

PURPOSE: Percutaneous transluminal angioplasty (PTA) is the first-line treatment for vascular access stenosis. To our knowledge, multicenter clinical research of PTA has not been reported in Japan. We examined the efficacy and safety of PTA for arteriovenous fistula (AVF) and arteriovenous graft (AVG) in five centers of Japan. METHODS: Three hundred cases of angioplasty for AVF and 300 for AVG were examined in three centers each. A hundred consecutive patients from each center who underwent PTA for AVG or AVF prior to March 2014 and met the inclusion criteria were searched retrospectively. Primary patency rates were estimated using the Kaplan-Meier method. RESULTS: The mean age was 69.3 ± 11.2 years in the AVF group and 70.2 ± 11.9 years in the AVG group. The anatomical success rates were 51.7% (155 of 300) in the AVF group and 72.0% (216 of 300) in the AVG group. The clinical success rates were 99.7% (299 of 300) in the AVF group and 100% (300 of 300) in the AVG group. A total of 25 complications (4.17%) were encountered in both groups including one major complication (0.17%). The primary patency was 99.0% at 1 month, 87.9% at 3 months and 51.7% at 6 months in the AVF group, and 96.0% at 1 month, 64.8% at 3 months and 20.4% at 6 months in the AVG group. CONCLUSIONS: The clinical success rate of PTA in five centers was relatively high and a major complication rate was only 0.17%. However, anatomical success rates were low comparing with the previous studies and the primary patency rates were inferior to the past data.

Is bypass graft technique effective in arteriovenous graft?

BACKGROUND: Arteriovenous graft (AVG) requires percutaneous transluminal angioplasty (PTA) to maintain its patency; however, bypass graft technique is often chosen in cases requiring PTA again within 3 months. We retrospectively examined whether bypass graft technique is effective for AVG. METHODS: The sample patient population consisted of 50 patients who underwent bypass graft technique on the venous side of the AVG between April 2012 and March 2014. The primary and assisted patencies of the technique were calculated, and compared by the type and length of the bypass graft. Kaplan-Meier method and log-rank test were used for the calculation and comparison of the patency, respectively. p<0.05 was considered statistically significant. RESULTS: The reasons for surgery were thrombotic occlusion (27 cases), frequent PTA (15 cases) and others (8 cases). Frequent PTA was conducted within 3 months in 22 of 27 thrombotic occlusion cases (making 37/50, or 74%). Moreover, thrombectomy was required in 34 cases (68%). The 1-year primary and 1-year assisted patencies of the technique were 6.5% and 72.6%, respectively. When the endpoint was frequent PTA within 3 months after the technique, 1-year primary patency was 45.9%. CONCLUSIONS: The 1-year primary patency of the technique was poor, and patency was hard to maintain without the assistance of PTA. Given that frequent PTA was conducted in 74% of patients, it may be a cause for the poor patency. Many cases required thrombectomies, which have the disadvantage of being more invasive than PTA. We concluded that bypass graft technique is not valuable for cases that received frequent PTA.

Change in skin perfusion pressure after the creation of upper limb arteriovenous fistula for maintenance hemodialysis access.

Arteriovenous fistula (AVF) is the most important vascular access method for hemodialysis (HD). However, ischemic steal syndrome occasionally develops. This study evaluated the change in skin perfusion pressure (SPP) after the creation of upper limb AVF and analyzed the relationship between blood flow measurements and the change in SPP. The subjects included 21 patients who underwent radiocephalic AVF creation for the first time between November 2012 and September 2013. We measured SPP on the palm side of the third finger of both hands and assessed blood flow measurements using ultrasound examination before and after the creation of AVF. The subjects consisted of 15 men and 6 women (average age: 65.3 ± 12.7 years, including 12 diabetic patients). Observational period between before and after surgery was 4.9 ± 5.2 days. None of the patients had ischemic steal syndrome after the creation of AVF. Skin perfusion pressure tended to decrease after creation of AVF on the finger of AVF side (100.0 ± 20.9 vs. 87.9 ± 26.5 mmHg, P = 0.063). In contrast, SPP did not change in the limb without AVF (97.9 ± 20.7 vs. 101.0 ± 19.4 mmHg, P = 0.615). The rate of change in SPP was significantly decreased on the finger of AVF side compared with that of limb without AVF (0.055% vs. -0.112%, P = 0.014). There was no correlation between the change in SPP and blood flow measurements. Skin perfusion pressure is possible to detect ischemic steal syndrome after the creation of upper limb AVF.

Complete resolution of tumoral calcinosis after renal transplantation.

A 41-year-old male receiving hemodialysis for 10 years was referred to our hospital for multiple masses progressively growing in multiple joints and buttocks, which were diagnosed as giant tumoral calcinosis (TC) by radiographic findings. He had been hypercalcemic and hyperphosphatemic with high doses of vitamin D for chronic kidney disease-mineral and bone disorder. We then stopped vitamin D to manage the hypercalcemia and hyperphosphatemia; however, the TC did not regress after 1.5 years, thus the patient underwent renal transplantation. Subsequently, the TC gradually but almost completely disappeared over the next 1.5 years. A renal transplantation was thus found to be useful for the successful treatment of TC.

Identification and characterization of major proteins carrying ABO blood group antigens in the human kidney.

BACKGROUND: It is generally admitted that ABO(H) blood group antigens are linked to lipids and proteins. Although glycolipids carrying ABO antigens have been well characterized in human kidneys, glycoproteins carrying ABO antigens are largely unknown, and their molecular properties remain to be elucidated. METHODS: All the blood group A antigen-linked proteins in human kidney could be solubilized and captured on immobilized Helix pomatia lectin that recognizes A antigens. These proteins were separated on SDS-PAGE gels. The gel pieces containing protein bands immunoreactive with anti-A antibody were excised, in-gel digested with trypsin, and analyzed by nanoLC tandem mass spectrometer. Protein candidates that carry ABO antigens were confirmed by immunoprecipitation and double-labeled immunofluorescense microscopy. RESULTS: All the glycoproteins carrying ABO antigens were found to be Asn-linked glycoproteins, and presented as multiple bands on SDS-PAGE with molecular masses ranging from 60 to 270 kDa. The protein bands were subjected for mass spectrometric analysis, which identified 121 distinct proteins with high confidence. Of the identified proteins, 55 N-glycosylated, membrane proteins were selected as glycoprotein candidates that carry ABO antigens. Among them, most abundantly expressed proteins as estimated by the number of peptide matches in the MS spectrometric analysis, such as platelet endothelial cell adhesion molecule 1, plasmalemmal vesicle-associated protein, and von Willebrand factor, were further characterized. CONCLUSIONS: Several glycoproteins were identified that represented major glycoproteins carrying ABO antigens in the human kidney, which exhibited distinct features in localization to most of vascular endothelial cells.

Overview of kidney and urine proteome databases.

With the completion or almost completion of genome sequences of many organisms in combination with the tremendous development of mass spectrometric analysis of proteins, several comprehensive proteomic studies, targeting whole organisms, body fluids, organs, tissues, cells, cellular organelles, or functional protein complexes, have produced valuable resources that can be shared and retrieved. In the present review, we provide current concept of construction of protein databases with special emphasis on high-throughput identification of protein using mass spectrometry, annotations, computational tools, and search engines to retrieve information of the identified proteins. We then update the current status of available protein databases of kidney and urine proteomes.

Human kidney glomerulus proteome and biomarker discovery of kidney diseases.

The kidney glomerulus is the site of plasma filtration and production of primary urine in the kidney. The structure not only plays a pivotal role in ultrafiltration of plasma into urine but also is the locus of kidney diseases progressing to chronic renal failure. Patients afflicted with these glomerular diseases frequently progress to irreversible loss of renal function and inevitably require replacement therapies. The diagnosis and treatment of glomerular diseases are now based on clinical manifestations, urinary protein excretion level, and renal pathology of needle biopsy specimens. The molecular mechanisms underlying the progression of glomerular diseases are still obscure despite a great number of clinical and experimental studies. Proteomics is a particularly promising approach for the discovery of proteins relevant to physiological and pathophysiological processes, and has been recently employed in nephrology. Although until now most efforts of proteomic analysis have been conducted with urine, the biological fluid that is easily collected without invasive procedures, proteomic analysis of the glomerulus, the tissue most proximal to the disease loci, is the most straightforward approach. In this review, we attempt to outline the current status of clinical proteomics of the glomerulus and provide a perspective of protein biomarker discovery of glomerular diseases.