Search

A 69-year-old woman, who had been diagnosed with interstitial pneumonia at 66 years of age, was admitted to our hospital because of high fever, purpura occurring on her arms and legs, and renal dysfunction. At the time of admission, her renal function had severely deteriorated (sCr 8.2 mg/dl, 24 h Ccr 6 ml/min), she had a severe high fever (BT 39.5 degrees C), back pain, a white blood cell count of 19,540/,microl, and a CRP level of 26.7 mg/dl. Blood and urine cultures yielded identical strains of E. coli. We diagnosed sepsis caused by pyelonephritis, and started intravenous meropenem trihydrate(MEPM) at 0.5 g/day. Her renal dysfunction was severe, so we started hemodialysis therapy. Immunological examination revealed the presence of ANCA-associated glomerulonephritis. Renal biopsy before steroid therapy confirmed the diagnosis of pauci-immune-type crescentic glomerulonephritis. Based on purpura and interstitial pneumonia, along with rapidly MPO-ANCA-positive progressive glomerulonephritis (RPGN) with acute renal failure, we diagnosed microscopic polyangitis (MPA). To treat sepsis and severe pyelonephritis, we started intravenous immunoglobulin 5 g (100 mg/kg)/day for 5 days before starting immunosuppressive steroid therapy (m-PSL 1 g/day, PSL 20 mg/day) for 3 days. These treatments improved her general condition and immediately improved her renal function. It is important to prevent infection during treatment using conventional immunosuppressive therapy. These findings suggest immunoglobulin therapy to be a safe immuno-suppressive treatment that is efficacious against ANCA-associated glomerulonephritis.

Immunoglobulin A (IgA) nephropathy is the most common form of primary glomerulonephritis worldwide. The pathogenesis of IgA nephropathy is unknown, but it is certain that some genetic factors are involved in susceptibility to the disease. Employing a large-scale, case-control association study using gene-based single-nucleotide polymorphism (SNP) markers, we previously reported four candidate genes. We report here an additional significant association between IgA nephropathy and an SNP located in the gene encoding immunoglobulin micro-binding protein 2 (IGHMBP2) at chromosome 11q13.2-q13.4. The association (chi2 =17.1, p = 0.00003; odds ratio of 1.85 with 95% confidence interval of 1.39-2.50 in a dominant association model) was found using DNA from 465 affected individuals and 634 controls. The SNP (G34448A) caused an amino acid substitution from glutamine to lysine (E928K). As the gene product is involved in immunoglobulin-class switching and patients with the A allele revealed higher serum levels of IgA (p = 0.048), the amino acid change might influence a class switch to increase serum IgA levels, resulting in a higher risk of IgA nephropathy.

We report a case of a 44-year-old woman with nephrotic syndrome who underwent renal biopsy three times. On each occasion, light microscopy showed membranous nephropathy with mild to moderate thickening of the glomerular capillary walls. Immunofluorescence microscopy showed predominant deposition of immunoglobulin (Ig) G, IgG1, IgG2, IgG3, and IgG4; C3; and C1q along the glomerular capillary walls and deposition of IgM and IgA in some parts of the walls. Electron microscopy revealed the accumulation of electron-dense deposits in the mesangium and the subepithelial area of the glomerular basement membrane. Virus-like particles were detected in the subendothelial cells in all three biopsy specimens. A definitive diagnosis of systemic lupus erythematosus (SLE) was made at the time of the second admission, when she was 31 years old. A diagnosis of membranous lupus nephritis was then made on the basis of the pathological and clinical findings. A change in anti-single-stranded (ss)DNA antibody titers was of particular interest in this patient. Occasional small increases in anti-double-stranded (ds)DNA antibody were found, but increased anti-ssDNA antibody titers occurred before there was any elevation of urinary protein during renal relapse, and a sustained increase in the titers was shown subsequently. Hypocomplementemia occurred in parallel with the increase of anti-ssDNA antibody. Immunosuppressive therapy with steroid promptly eliminated anti-dsDNA antibody, but anti-ssDNA antibody remained positive. The patient had normocomplementemia and proteinuria was absent. Later, anti-ssDNA antibody decreased. Renal function has remained in the normal range for 20 years.

Background: Coronary artery calcification (CAC) is thought to be associated with greater cardiovascular mortality in patients with end-stage renal disease than in nonuremic persons. The purpose of the present study is to assess the effects of etidronate, a synthetic analogue of pyrophosphate, on progression of CAC score., Methods: The extent of CAC was evaluated by using multidetector spiral computed tomography. Repeated CAC score estimation was possible in 35 patients (29 men, 6 women). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Serum osteoprotegerin (OPG) was measured by using enzyme-linked immunoassay. Serum etidronate was measured by means of the gas spectrometry technique using deuterium-labeled etidronate as internal standard., Results: Mean patient age was 63.2 +/- 8.2 (SD) years, and mean duration of dialysis therapy was 7.4 +/- 5.5 years. CAC score was estimated 3 times in each patient. After the second CAC score estimation, 35 patients were administered etidronate, 200 mg/d, for 14 days. This cycle was repeated 3 times every 90 days. CAC progression was significantly less pronounced during treatment with etidronate compared with the period before treatment was initiated. The median annualized absolute increase in calcified volume was 195.0 mm3 without treatment compared with -490.0 mm3 during treatment ( P < 0.01). Patients were divided into 2 groups based on changes in CAC score during etidronate treatment. Responders (n = 26) were patients whose CAC score decreased during therapy, and nonresponders (n = 9) were patients whose CAC score increased, even after etidronate therapy. Serum C-reactive protein values (0.18 +/- 0.13 mg/dL) in the responder group were greater than those (0.14 +/- 0.08 mg/dL) in the nonresponder group ( P = 0.013). Serum OPG levels decreased significantly during etidronate therapy (256.8 +/- 93.8 versus 245.0 +/- 83.0 pg/mL; P = 0.0161). Etidronate was well tolerated during the study. BMD values during etidronate therapy were not significantly changed from 0.941 +/- 0.125 to 0.968 +/- 0.246 g/cm2., Conclusion: Results of the present study suggest that the extent of CAC may be suppressed by etidronate in association with a reduction in chronic inflammatory responses. They also suggest that a decrease in serum OPG concentrations by means of etidronate may be associated with changes in vascular calcification in dialysis patients.

Background: In diabetic nephropathy, tubulointerstitial fibrosis is an important component of renal injury. Transforming growth factor (TGF)-beta is a key cytokine that is involved in the pathogenesis of tubulointerstitial fibrosis. However, signal transduction cascades of TGF-beta under high-glucose conditions remain to be clarified. We undertook this study to elucidate whether mitogen-activated protein (MAP) kinase and Smad proteins were involved in TGF-beta-induced fibronectin (FN) production under high glucose in NRK fibroblasts., Methods: After serum restriction, NRK cells were exposed to either normal glucose (5.5 mM d-glucose), high glucose (30 mM d-glucose), or 30 mM l-glucose in the presence or absence of TGF-beta for 24 h. MAP kinase inhibitors (SB 203580 and PD 98059) were added to the cultured NRK fibroblasts 2 h before TGF-beta1, and the incubations continued for 8 h. The phosphorylation of p38 MAP kinase, extracellular signal-regulated kinase (ERK)1/ERK2, and c-Jun N-amino terminal kinase (JNK) was assessed by immunoblotting. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were performed to determine FN mRNA and protein expression, respectively., Results: High glucose significantly increased the expression of FN mRNA, by 2.4 +/- 1.4-fold. In the presence of either SB 203580 or PD 98059, the high glucose-induced FN mRNA increase was completely inhibited. Incubation of NRK fibroblasts for 48 h in 30 mM d-glucose did not alter p38 MAP kinase, ERK1/ERK2, or JNK phosphorylation. The addition of exogenous TGF-beta1 (1 ng/ml) for 8 h increased FN mRNA by 2.7 +/- 1.1-fold. Both the TGF-beta1- and high glucose-induced FN mRNA increases were inhibited by SB 203580 and PD 98059. Dominant-negative Smad4 did not affect the FN mRNA increase induced by TGF-beta1 and high glucose. Exogenous TGF-beta1 under both normal and high glucose, enhanced the phosphorylation of both p38 MAP kinase and ERK1/ERK2, but not that of JNK., Conclusions: NRK fibroblasts exposed to high glucose demonstrated increased TGF-beta1-induced p38 MAP kinase activation. The FN synthesis induced by high glucose and TGF-beta1 was not affected by the Smads pathway and was not due to increased osmolarity. The enhanced activation of p38 MAP kinase may contribute to the altered fibroblast phenotype that leads to progressive diabetic nephropathy.

Cardiovascular disease in association with coronary artery calcification (CAC) is the leading cause of death in patients with end-stage renal disease (ESRD). The evaluation of CAC has been performed by electron beam CT scan. The purpose of the present study was to assess CAC using multi-detector spiral CT (MDCT) and to evaluate contributors to CAC in these patients. Fifty-three patients on chronic hemodialysis participated in this study. Their mean age was 61.0+/-9.6 years, and the mean duration of dialysis therapy was 6.7+/-5.4 years. We used an automatic device to measure arterial pulse wave velocity (PWV) as an index of arterial wall stiffness. The aortic calcification index (ACI) was quantified morphometrically by CT scan. The CAC score correlated positively with ACI score (r =0.863, p <0.0001). Linear regression analysis indicated that the CAC scores correlated positively with age (r =0.406, p =0.0023), C-reactive protein (r =0.38, p =0.0047) and PWV (r =0.303, p =0.0271). Stepwise regression analysis indicated that ACI (beta-coefficient=0.862, p <0.0001) and arterial PWV (beta-coefficient=0.303, p <0.0001) were independently associated with CAC score. The mean CAC score of patients with cardiac events (2,568.5+/-2,575.1 mm3) was significantly higher than that (258.0+/-409.2 mm3) of patients without cardiac events. In conclusion, our results showed clearly that assessment of CAC score using MDCT may be predictive for detecting the presence of coronary artery disease. CAC is indirectly associated with increased arterial stiffness and the extent of aortic calcification in hemodialysis patients. We did not find a significant correlation between CAC score and parameters of mineral metabolism, including serum levels of calcium, phosphorus and parathyroid hormone. A longitudinal prospective study is required to assess the predictive value of this technique in determining cardiac events in large numbers of hemodialysis patients.

The M(1) and M(3) subtypes are the major muscarinic acetylcholine receptors in the salivary gland and M(3) is reported to be more abundant. However, despite initial reports of salivation abnormalities in M(3)-knockout (M(3)KO) mice, it is still unclear which subtype is functionally relevant in physiological salivation. In the present study, salivary secretory function was examined using mice lacking specific subtype(s) of muscarinic receptor. The carbachol-induced [Ca(2+)](i) increase was markedly impaired in submandibular gland cells from M(3)KO mice and completely absent in those from M(1)/M(3)KO mice. This demonstrates that M(3) and M(1) play major and minor roles, respectively, in the cholinergically induced [Ca(2+)](i) increase. Two-dimensional Ca(2+)-imaging analysis revealed the patchy distribution of M(1) in submandibular gland acini, in contrast to the ubiquitous distribution of M(3). In vivo administration of a high dose of pilocarpine (10 mg kg(-1), s.c.) to M(3)KO mice caused salivation comparable to that in wild-type mice, while no salivation was induced in M(1)/M(3)KO mice, indicating that salivation in M(3)KO mice is caused by an M(1)-mediated [Ca(2+)](i) increase. In contrast, a lower dose of pilocarpine (1 mg kg(-1), s.c.) failed to induce salivation in M(3)KO mice, but induced abundant salivation in wild-type mice, indicating that M(3)-mediated salivation has a lower threshold than M(1)-mediated salivation. In addition, M(3)KO mice, but not M(1)KO mice, had difficulty in eating dry food, as shown by frequent drinking during feeding, suggesting that salivation during eating is mediated by M(3) and that M(1) plays no practical role in it. These results show that the M(3) subtype is essential for parasympathetic control of salivation and a reasonable target for the drug treatment and gene therapy of xerostomia, including Sjögren's syndrome.

Background: Osteoprotegerin (OPG) is a glycoprotein that inhibits osteoclast differentiation and activity. OPG-deficient mice develop severe osteoporosis and medial arterial calcification. The expression of OPG is detected in early atherosclerotic lesions in non-uraemic patients. We examined whether serum OPG is associated with aortic calcification in haemodialysis patients., Methods: Serum OPG was measured in 102 patients who were undergoing haemodialysis. The aortic calcification index (ACI) was assessed by computed tomography scans., Results: Serum OPG level, measured by enzyme-linked immunosorbent assay, was significantly greater in patients with higher ACI than in those with lower ACI. There was a direct relationship between ACI and serum OPG levels and a positive association between OPG and ACI (r = 0.483, P<0.0001). Multiple regression analyses indicated that serum OPG levels were independently associated with the severity of aortic calcification (P<0.0001)., Conclusions: These findings show that serum OPG levels are associated with the extent of vascular calcification, suggesting that OPG may be involved in the development of vascular calcification in haemodialysis patients.

The type 1 inositol 1,4,5-trisphosphate receptor (IP(3)R1) is an intracellular Ca(2+) channel protein that plays crucial roles in generating complex Ca(2+) signalling patterns. IP(3)R1 consists of three domains: a ligand-binding domain, a regulatory domain and a channel domain. In order to investigate the function of these domains in its gating machinery and the physiological significance of specific cleavage by caspase 3 that is observed in cells undergoing apoptosis, we utilized various IP(3)R1 constructs tagged with green fluorescent protein (GFP). Expression of GFP-tagged full-length IP(3)R1 or IP(3)R1 lacking the ligand-binding domain in HeLa and COS-7 cells had little effect on cells' responsiveness to an IP(3)-generating agonist ATP and Ca(2+) leak induced by thapsigargin. On the other hand, in cells expressing the caspase-3-cleaved form (GFP-IP(3)R1-casp) or the channel domain alone (GFP-IP(3)R1-ES), both ATP and thapsigargin failed to induce increase of cytosolic Ca(2+) concentration. Interestingly, store-operated (-like) Ca(2+) entry was normally observed in these cells, irrespective of thapsigargin pre-treatment. These findings indicate that the Ca(2+) stores of cells expressing GFP-IP(3)R1-casp or GFP-IP(3)R1-ES are nearly empty in the resting state and that these proteins continuously leak Ca(2+). We therefore propose that the channel domain of IP(3)R1 tends to remain open and that the large regulatory domain of IP(3)R1 is necessary to keep the channel domain closed. Thus cleavage of IP(3)R1 by caspase 3 may contribute to the increased cytosolic Ca(2+) concentration often observed in cells undergoing apoptosis. Finally, GFP-IP(3)R1-casp or GFP-IP(3)R1-ES can be used as a novel tool to deplete intracellular Ca(2+) stores.

Left ventricular hypertrophy (LVH) is the most frequent cardiac abnormality in patients with end-stage renal disease (ESRD). Recent studies have shown that arterial stiffness is associated with mediacalcinosis in these patients. However, whether arterial stiffness and vascular calcification are associated with the LVH in patients with ESRD has not been well established. Forty-nine patients on chronic hemodialysis participated in this study. 1) To better understand the mechanism underlying the increased incidence of LVH, we studied the relation between LVH and each of arterial wall stiffness, aortic calcification, and numerous clinical parameters in 49 patients on chronic hemodialysis. 2) To evaluate the contribution of arterial stiffness and arterial calcification to LVH in hemodialysis patients, we performed the present clinical analysis on 49 patients on chronic hemodialysis. We used an automatic device to measure arterial pulse wave velocity (PWV) as an index of arterial wall stiffness. The aortic calcification index (ACI) was quantified morphometrically by CT scan. The left ventricular mass index (LVMI) was estimated by M-mode echocardiography. To understand the mechanism underlying the increased incidence of LVH, we examined the factors contributing to LVMI in these patients. The correlation between each of the study parameters and LVMI as an indicator of LVH was then examined. The LVMI value was correlated positively with PWV (r=0.439, p=0.0014), systolic blood pressure (r=0.421, p=0.0023), and ACI (r=0.467, p=0.0006). A stepwise linear regression analysis showed that PWV, systolic blood pressure, and ACI were independently associated with LVH in our subjects. These results suggest that LVH is associated with hypertension, increased arterial stiffness, and the extent of vascular calcification in hemodialysis patients, with vascular calcification being the most important contributor to the development of LVH. Alteration of pulsatile dynamics contributes to an increase in left ventricular load and thus is also related to the LVH in these patients. These results suggest that LVH is associated with hypertension, increased arterial stiffness, and the extent of vascular calcification in hemodialysis patients. Vascular calcification, which alters the pulsatile dynamics and thereby contributes to an increase in left ventricular load, is the most important contributor to the development of LVH in patients undergoing hemodialysis.

Background: The aortic calcification index (ACI), estimated on abdominal computed tomographic scans, has been associated with the extent of arteriosclerosis in hemodialysis patients. However, the contribution of biochemical markers to the progression of vascular calcification in patients undergoing hemodialysis is not fully understood., Methods: We examined the relationship between coronary risk factors; metabolic factors, including serum osteoprotegerin (OPG) concentration; and progression of vascular calcification in 26 dialysis patients., Results: Mean patient age was 52.6 +/- 8.7 (SD) years, and mean duration of dialysis therapy was 7.7 +/- 5.8 years. ACI was measured twice in each patient, and the mean interscan period was 4.9 +/- 0.3 years. Mean ACI changed from 22.2 +/- 24.2 to 33.9 +/- 28.8 overall, and mean change in ACI (DeltaACI) was 12.0 +/- 9.9. Patients were divided into 2 groups: slow progressors, with DeltaACI of 4.1 +/- 3.2 (n = 13), and rapid progressors, with DeltaACI of 19.8 +/- 7.9 (n = 13). Serum fasting glucose and CRP levels of rapid progressors were high, and their serum albumin and intact parathyroid hormone levels were low. Multiple regression analyses showed that serum OPG levels were independently associated with vascular calcification in the hemodialysis patients studied., Conclusion: Rapid progression of vascular calcification was associated with dose of calcium carbonate prescribed and serum OPG concentration. The clinical significance of these observations remains to be determined.

Angiotensin II (AT II) is thought to be associated with the development of renal interstitial fibrosis. However, the molecular mechanisms of the interstitial fibrosis have not been extensively studied. We have examined the role of mitogen-activated protein kinases (MAPKs) on fibronectin (FN) accumulation in cultured normal rat kidney interstitial fibroblasts (NRK 49F cell line). AT II caused dose-dependent increases in FN accumulation and FN mRNA in these cells. AT II also activated the extracellular signal-regulated kinase (ERK) and p38 MAPK in the presence of AT II. These increases in FN accumulation and activation of MAPKs were inhibited with AT I receptor antagonist (ARB; CV-11974) in renal interstitial fibroblasts. The inhibitors against ERK (PD98059) and p38 MAPK (SB203580) significantly inhibited AT II-induced increases in FN mRNA. These findings suggest that the MAPKs play an important role in AT II-mediated renal interstitial fibrosis and that ARB may be useful for preventing renal interstitial fibrosis.

To understand the molecular mechanism of ligand-induced gating of the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R)/Ca(2+) release channel, we analyzed the channel properties of deletion mutants retaining both the IP(3)-binding and channel-forming domains of IP(3)R1. Using intrinsically IP(3)R-deficient cells as the host cells for receptor expression, we determined that six of the mutants, those lacking residues 1-223, 651-1130, 1267-2110, 1845-2042, 1845-2216, and 2610-2748, did not exhibit any measurable Ca(2+) release activity, whereas the mutants lacking residues 1131-1379 and 2736-2749 retained the activity. Limited trypsin digestion showed that not only the IP(3)-gated Ca(2+)-permeable mutants lacking residues 1131-1379 and 2736-2749, but also two nonfunctional mutants lacking residues 1-223 and 651-1130, retained the normal folding structure of at least the C-terminal channel-forming domain. These results indicate that two regions of IP(3)R1, viz. residues 1-223 and 651-1130, are critical for IP(3)-induced gating. We also identified a highly conserved cysteine residue at position 2613, which is located within the C-terminal tail, as being essential for channel opening. Based on these results, we propose a novel five-domain structure model in which both N-terminal and internal coupling domains transduce ligand-binding signals to the C-terminal tail, which acts as a gatekeeper that triggers opening of the activation gate of IP(3)R1 following IP(3) binding.

Objectives: To compare the erosion of glass ionomer, zinc phosphate and polycarboxylate cements using volumetric and gravimetric methods., Methods: For the volumetric method, the eroded depth of cement placed in a cylindrical cavity in PMMA was measured using a dial gauge after immersion in an eroding solution. For the gravimetric method, the weight of the residue of a solution in which a cylindrical specimen had been immersed was measured. 0.02 M lactic acid solution (0.02 M acid) and 0.1 M lactic acid/sodium lactate buffer solution (0.1 M buffer) were used as eroding solutions. The pH of both solutions was 2.74 and the test period was 24 h., Results: Ranking of eroded depth and weight of residue was polycarboxylate>zinc phosphate>glass ionomers. Differences in erosion were more clearly defined by differences in eroded depth than differences in weight of residue. In 0.02 M acid, the erosion of glass ionomer using the volumetric method was effected by the hygroscopic expansion. In 0.1 M buffer, the erosion for polycarboxylate and zinc phosphate using the volumetric method was much greater than that using the gravimetric method. This is explained by cryo-SEM images which show many holes in the surface of specimens after erosion. It appears that zinc oxide is dissolved leaving a spongy matrix which easily collapses under the force applied to the dial gauge during measurement., Significance: The volumetric method that employs eroded depth of cement using a 0.1 M buffer solution is able to quantify erosion and to make material comparisons.

Background: To elucidate the role of mast cells (MCs) in the pathogenesis of crescentic glomerulonephritis, we investigated the immunohistochemical localization of MCs in the kidney and the correlation between MC localization and tubulointerstitial lesions in biopsy specimens and serum stem cell factor (SCF) levels in patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated glomerulonephritis., Methods: Thirteen patients with ANCA-associated glomerulonephritis were enrolled in this study. Clinical parameters, such as serum creatinine and urinary protein excretion, were obtained from each patient at the time of biopsy. Paraffin-embedded sections were used for immunohistochemical staining, using the labelled streptavidin bio-tin (LSAB) method. Monoclonal antibodies to human tryptase, alpha-smooth-muscle actin, and CD68 were used as primary antibodies. Ten cortical interstitial fields were randomly selected at an original magnification of x400 and assessed using a computer-assisted color image analyzer. Tubulointerstitial fibrosis was assessed as the percentage of the area stained with Masson trichrome in ten cortical interstitial fields. The measurement of serum SCF levels was performed by using an enzyme-linked immunoassay., Results: In all of the control subjects, a few tryptase-positive MCs were observed in the glomeruli and interstitium. In contrast, sparse MCs were observed in the interstitium, but not in the glomeruli of diseased kidneys. The number of interstitial MCs in the tubulointerstitial lesions was positively correlated with the degree of interstitial fibrosis. Moreover, a significant positive correlation was observed between the number of interstitial MCs and the serum SCF concentration (r = 0.85; P = 0.001)., Conclusions: Our findings suggest that MC infiltration induced by SCF in interstitial tissues seems to be associated with tubulointerstitial fibrosis in human ANCA-associated glomerulonephritis.

The NPHS2 gene encoding the podocin protein was causally linked to the autosomal recessive type of steroid-resistant nephrotic syndrome. In this study, we investigated the consequence of the R138Q mutation of podocin, one of the most common missense mutations in the NPHS2 gene, by examining the expression of the wild-type and R138Q mutant podocins in mammalian cells. Either myc- or FLAG-tagged wild-type podocin was strongly stained in plasma membrane, particularly in the fine processes wherein the protein was colocalized with actin stress fibers. On the other hand, the R138Q mutant podocin was completely retained intracellularly and colocalized with the endoplasmic reticulum (ER) marker, calnexin. These results suggest that the R138Q mutation affected podocin protein folding, thereby interfering with the mutant protein's departure from the ER. To determine if the ER retention of R138Q mutant is correctable, cells were incubated with the chemical chaperones glycerol, trimethylamine-N-oxide, and DMSO. Using these two methods, namely, cell surface labeling with sulfo-NHS-S-S-biotin and Alexa 488-streptavidin, and immunostaining to detect the podocin protein close to the plasma membrane, we confirmed that these chemical chaperone treatments elicit a cellular redistribution of R138Q podocin. Our results reveal defective cellular processing of the mutant podocin, and provide evidence for pharmacological correction of the processing defect.

Progression to chronic renal failure is influenced by the extent of irreversible interstitial fibrosis. For a quantitative evaluation of interstitial fibrosis, we attempted color extraction of the interstitial area treated with Masson-Trichrome stain using an image analyzer. The subjects were 20 cases of IgA nephropathy with a mean age of 33.4 +/- 12.3 years. The interstitial lesions were graded simultaneously by renal pathologists without clinical information. In addition, immunohistochemical studies using specific antibodies against type III collagen, alpha-smooth muscle actin and CD34 were performed to further characterize the interstitial lesions. The percentage of interstitium in the renal cortex evaluated by an image analyzer was significantly correlated with the pathological grade of fibrous interstitial damage(sigma = 0.861, p < 0.0002), the type III collagen-positive area(sigma = 0.954, p < 0.0001) and alpha-smooth muscle actin-positive area(sigma = 0.686, p = 0.0005). Moreover, the percentage of interstitium was negatively correlated with 24-hr creatinine clearance(r = -0.744, p < 0.0001) and the numbers of peritubular capillaries detected by CD34(r = -0.649, p < 0.0014). These findings suggest that color extraction of the interstitial area stained with Masson-Trichrome using image analysis is useful for a quantitative evaluation of the interstitial fibrous lesions in IgA nephropathy.

Immunoglobulin A nephropathy (IgAN) is a primary glomerulonephritis of common incidence world-wide whose etiology and pathogenesis remain unresolved, although genetic factors are assumed to be involved in the development and progression of this disease. To identify genetic variations that might confer susceptibility to IgAN, we performed a case-control association study involving 389 Japanese IgAN patients and 465 controls. Genome-wide analysis of approximately 80,000 single-nucleotide polymorphisms (SNPs) identified a significant association between IgAN and six SNPs located in the PIGR (polymeric immuoglobulin receptor) gene at chromosome 1q31-q41. One of them, PIGR-17, caused an amino-acid substitution from alanine to valine at codon 580 (chi(2)=13.05, P=0.0003, odds ratio [OR] =1.59, 95% confidence interval [95% CI] =1.24-2.05); the OR of minor homozygotes to others was 2.71 (95% CI=1.31-5.61). Another SNP, PIGR-2, could affect promoter activity (chi(2)=11.95, P=0.00055, OR=1.60, 95% CI=1.22-2.08); the OR of minor homozygotes to others was 2.08 (95% CI=0.94-4.60). Pairwise analyses demonstrated that all six SNPs were in almost complete linkage disequilibrium. Biopsy specimens from IgAN patients were positively stained by antibody against the secretory component of PIGR, but corresponding tissues from non-IgAN patients were not. Our results suggest that a gene associated with susceptibility to IgAN lies within or close to the PIGR gene locus on chromosome 1q in the Japanese population.

Objective: The present study was undertaken to evaluate clinical application of serum cystatin C as a new marker of glomerular filtration rate (GFR) in patients with various renal diseases., Patients and Methods: A total of 140 patients were enrolled in the study. We measured the serum cystatin C levels and compared them with creatinine clearance (Ccr) and inulin clearance (Cin) as an indicator of GFR., Results: There was a significant positive correlation between serum cystatin C and creatinine levels (r=0.928). Serum cystatin C was inversely correlated with creatinine clearance. Moreover, the reciprocal serum cystatin C level was positively correlated with Cin (r=0.882). The receiver-operating characteristic curve of serum cystatin C and creatinine demonstrated that the diagnostic accuracy of the serum cystatin C level is superior to that of creatinine in identifying individuals with reduced GFR., Conclusion: These results indicated that measurement of serum cystatin C is useful to estimate GFR, and in particular, to detect a mild reduction of GFR in patients with renal diseases.

Immunotactoid glomerulopathy (ITG) demonstrates glomerular deposits that are characterized by highly organized ultrastructure. The deposits appear to be composed of immunoglobulin and complement that were negative for amyloid by Congo red stain. However, it has been difficult to distinguish the difference between ITG and fibrillary glomerulonephritis. In the present study, we performed an immunoelectron microscopic study to identify the factors that seemed to be associated with the glomerular deposits in a case of IgA-dominant ITG. IgA, light chain kappa and fibrinogen were colocalized in association with fibrillar deposits in the extracellular matrix of mesangial cells. Therefore, it is likely that the complex of IgA, light chain kappa and fibrinogen are associated with the formation of highly organized ultrastructural deposits in a case of IgA-dominant ITG.

End-stage renal failure (ESRD) induces a clinical state of immunodeficiency with a higher incidence of infections and a higher mortality due to infectious complications compared with the normal population. Using a newly developed immunofluorescent staining of intracellular cytokines for flow cytometric analysis, we studied Th subsets in 22 healthy control subjects, 28 patients with compensated chronic renal failure (CRF), 25 patients on hemodialysis (HD), and 24 patients on continuous ambulatory peritoneal dialysis (CAPD). Our results demonstrate that the percentage of both interferon-gamma-positive cells and interleukin-4-positive cells increased in compensated CRF patients compared with those in healthy subjects. Moreover, a significantly higher percentage of CD4-positive cells is characterized by a Th1-type cytokine production pattern in HD patients and by a Th2-type cytokine secretion pattern in CAPD patients. These results suggest that the altered Th1/Th2 balance may be associated with the pathogenesis of ESRD., (Copyright 2002 S. Karger AG, Basel)

IgA nephropathy (IgAN) frequently accompanies glomerular basement membrane (GBM) alterations. To clarify the compositional changes of the GBM in IgAN, we examined the glomerular expression of alpha2(IV) and alpha5(IV) chains of type IV collagen in 36 patients with IgAN. Increased expression of the alpha2(IV) chain was observed in the expanded mesangium, and there were segmental sclerotic lesions of glomeruli in which the expression of the alpha5(IV) chain in the GBM was reduced. These lesions were found in 11 out of the 36 patients (30.6%). The patients with these lesions had more proteinuria, lower creatinine clearance and severer histological changes than the patients without them. On the other hand, a partial reduction of alpha5(IV) chain in normal-appearing GBM was observed in 15 out of the 36 patients (41.7%). The patients with this lesion had a longer disease period before biopsy than the patients without it. No other clinical and histological parameters were related to the partial reduction of alpha5(IV) in the GBM. In conclusion, an imbalance of glomerular alpha2(IV) and alpha5(IV) chain expression occurred in IgAN. This may be associated with the morphological changes of glomerular sclerosis and GBM alterations in IgAN. Further studies are required to understand the pathogenesis of the abnormal expression of type IV collagen chains., (Copyright 2002 S. Karger AG, Basel)

Although intensive efforts have been undertaken to elucidate the genetic background of immunoglobulin A nephropathy (IgAN), genetic factors associated with the pathogenesis of this disease are still not well understood. We designed a case-control association study that was based on linkage disequilibrium among single-nucleotide polymorphisms (SNPs) in the selectin gene cluster on chromosome 1q24-25, and we found two SNPs in the E-selectin gene (SELE8 and SELE13) and six SNPs in the L-selectin gene (SELL1, SELL4, SELL5, SELL6, SELL10, and SELL11) that were significantly associated with IgAN in Japanese patients. All eight SNPs were in almost complete linkage disequilibrium. SELE8 and SELL10 caused amino acid substitutions from His to Tyr and from Pro to Ser (chi2=9.02, P=.0026, odds ratio = 2.73 [95% confidence interval [CI] 1.38--5.38] for His-to-Tyr substitutions; chi2=17.4, P=.000031, odds ratio = 3.61 [95% CI 1.91--6.83] for Pro-to-Ser substitutions), and SELL1 could affect promoter activity of the L-selectin gene (chi2=19.5, P=.000010, odds ratio = 3.77 [95% CI 2.02--7.05]). The TGT haplotype at these three loci was associated significantly with IgAN (chi2=18.67, P=.000016, odds ratio = 1.88 [95% CI 1.41--2.51]). Our results suggest that these eight SNPs in selectin genes may be useful for screening populations susceptible to the IgAN phenotype that involves interstitial infiltration.

We report a rare case of nephrotic syndrome in an elderly woman with positive antineutrophil cytoplasmic antibody(ANCA). The patient was 81 years of age and had a history of interstitial pneumonia. She was diagnosed rheumatoid arthritis(RA) at admission. Rapidly progressing renal damage was found with mild microscopic hematuria and positive ANCA. The renal biopsy findings indicated membranous nephropathy. Neither gold nor anti-rheumatic drugs had been previously administered. She may have had an RA-specific membranous nephropathy. Crescentic formation was not clear. With hematuria, the leukocyte infiltration in the capillary lumen and the change in epithelial cells of Bowman's capsules would be histological findings suggesting ANCA-associated nephritis. This is a rare report on membranous nephropathy in an RA patient with ANCA-associated nephritis.

Immunoglobulin A nephropathy (IgAN) is a form of chronic glomerulonephritis of unknown etiology and pathogenesis. Immunogenetic studies have not conclusively indicated that human leukocyte antigen (HLA) is involved. As a first step in investigating a possible relationship between HLA class II genes and IgAN, we analyzed the extent of linkage disequilibrium (LD) in this region of chromosome 6p21.3 in a Japanese test population and found extended LD blocks within the class II locus. We designed a case-control association study of single-nucleotide polymorphisms (SNPs) in each of those LD blocks, and determined that SNPs located in the HLA- DRA gene were significantly associated with an increased risk of IgAN ( P = 0.000001, odds ratio = 1.91 [95% confidence interval 1.46-2.49]); SNPs in other LD blocks were not. Our data imply that some haplotype of the HLA- DRA locus has an important role in the development of IgAN in Japanese patients.

Low-dose cyclosporin(CsA) therapy combined with prednisolone was performed in 10 adult patients with frequently relapsing minimal change nephrotic syndrome(MCNS). Oral CsA was administered at the dose of 1-3 mg/kg/day(50-150 mg/day) in combination with preceding prednisolone(32.5 +/- 13.1 mg/day). The whole blood traugh concentration of CsA was maintained at the level of 50-100 ng/ml (ranging in 35-160 ng/ml, mean: 68.0 +/- 42.8 ng/ml), and the therapy was continued for 31.7 +/- 12.7 months. The urinary protein excretion, serum total protein, albumin and total cholesterol significantly improved after treatment. The serum creatinine increased slightly at 3-6 months after treatment, but decreased to within the normal range thereafter. The frequency of relapse and the ratio of the complete remission period to the total observed period were compared between the pre-treatment period(36.6 +/- 42.5 months) and post-treatment period(31.7 +/- 12.7 months). The frequency of relapse was significantly decreased after CsA treatment(2.3 +/- 1.5 times/year-->0.7 +/- 0.7 times/year, p = 0.02). The ratio of the complete remission period to the total observed period was increased significantly after CsA therapy(61.7 +/- 24.3%-->88.6 +/- 14.5%, p = 0.01). Thus, the low dose cyclosporin(CsA) therapy combined with prednisolone was an effective treatment for adult MCNS patients who relapsed frequently under conventional prednisolone therapy.