Sustained inflammation after pericyte depletion induces irreversible blood-retina barrier breakdown.

In the central nervous system, endothelial cells (ECs) and pericytes (PCs) of blood vessel walls cooperatively form a physical and chemical barrier to maintain neural homeostasis. However, in diabetic retinopathy (DR), the loss of PCs from vessel walls is assumed to cause breakdown of the blood-retina barrier (BRB) and subsequent vision-threatening vascular dysfunctions. Nonetheless, the lack of adequate DR animal models has precluded disease understanding and drug discovery. Here, by using an anti-PDGFRß antibody, we show that transient inhibition of the PC recruitment to developing retinal vessels sustained EC-PC dissociations and BRB breakdown in adult mouse retinas, reproducing characteristic features of DR such as hyperpermeability, hypoperfusion, and neoangiogenesis. Notably, PC depletion directly induced inflammatory responses in ECs and perivascular infiltration of macrophages, whereby macrophage-derived VEGF and placental growth factor (PlGF) activated VEGFR1 in macrophages and VEGFR2 in ECs. Moreover, angiopoietin-2 (Angpt2) upregulation and Tie1 downregulation activated FOXO1 in PC-free ECs locally at the leaky aneurysms. This cycle of vessel damage was shut down by simultaneously blocking VEGF, PlGF, and Angpt2, thus restoring the BRB integrity. Together, our model provides new opportunities for identifying the sequential events triggered by PC deficiency, not only in DR, but also in various neurological disorders.

A nationwide survey of rapidly progressive glomerulonephritis in Japan: etiology, prognosis and treatment diversity.

BACKGROUND: The etiology, prevalence, and prognosis of rapidly progressive glomerulonephritis (RPGN) including renal vasculitis vary among races and periods. METHOD: To improve the prognosis of Japanese RPGN patients, we conducted a nationwide survey of RPGN in the nephrology departments of 351 tertiary hospitals, and found 1772 patients with RPGN (Group A: diagnosed between 1989 and 1998, 884 cases; Group B: diagnosed between 1999 and 2001, 321 cases; and Group C: diagnosed between 2002 and 2007, 567 cases). ANCA subclasses, renal biopsy findings, treatment, outcome and cause of death were recorded. RESULT: The most frequent primary disease was renal-limited vasculitis (RLV) (42.1%); the second was microscopic polyangiitis (MPA) (19.4%); the third was anti-GBM-associated RPGN (6.1%). MPO-ANCA was positive in 88.1% of RLV patients and 91.8% of MPA patients. The proportion of primary renal diseases of RPGN was constant during those periods. The most frequent cause of death was infectious complications. The serum creatinine at presentation and the initial dose of oral prednisolone decreased significantly in Groups B and C compared to Group A. However, both patient and renal survival rates improved significantly in Groups B and C (survival rate after six months in Group A: 79.2%, Group B: 80.1%, and Group C: 86.1%. Six-month renal survival in Group A: 73.3%, Group B: 81.3%, and Group C: 81.8%). CONCLUSION: Early diagnosis was the most important factor for improving the prognosis of RPGN patients. To avoid early death due to opportunistic infection in older patients, a milder immunosuppressive treatment such as an initial oral prednisolone dose reduction with or without immunosuppressant is recommended.

Validity of retrospective review of medical records as a means of identifying adverse events: comparison between medical records and accident reports.

AIMS: This study was undertaken to investigate whether the adverse events recorded in accident reports could be properly identified by a retrospective review of medical records. METHODS: In an acute-care hospital, a retrospective review of 200 medical records, consisting of the medical records for the 100 cases for which accident reports were reported and an additional 100 cases extracted at random from the medical records of patients discharged in FY 2002, was conducted. The retrospective review of the medical records consisted of two stages. In the first stage, the medical records were screened by a nurse leader (Review A) and by a group of nurses trained by the nurse leader (Review B). In the second stage, a doctor review team determined the presence of adverse events. RESULTS: Of the 61 accident reports that satisfied at least one of the 18 criteria to screen potential adverse events, 28 were ultimately judged to be adverse events in this study. Of these 28 events, Review A identified 25 (89.3%) and Review B identified 24 (85.7%). One adverse event was overlooked during Review A, and two events were overlooked during Review B. The two adverse events not identified by either Review A or Review B were not adequately described in the medical records. CONCLUSIONS: Some adverse events could not be identified by retrospective reviews of medical records, partly because of inadequate descriptions. However, when adequate information was available, adverse events could be identified with a very high degree of accuracy.

A scoring system to predict renal outcome in IgA nephropathy: from a nationwide prospective study.

BACKGROUND: Immunoglobulin A (IgA) nephropathy is the most common form of glomerulonephritis in the world, and a substantial number of patients develop end-stage renal disease (ESRD). Although there are several prognostic indicators, it remains difficult to predict the renal outcome in individual patients. METHODS: A prospective cohort study was conducted in 97 clinical units in Japan from 1995 to 2002. We analysed the data from 2269 patients using proportional hazards models in order to determine the predictors of ESRD in IgA nephropathy and to develop a scoring system to estimate ESRD risk. RESULTS: During the follow-up (median, 77 months), 207 patients developed ESRD. Systolic hypertension, proteinuria, hypoproteinaemia, azotaemia and a high histological grade at initial renal biopsy were independently associated with the risk of ESRD. Mild haematuria predisposed patients to ESRD more than severe haematuria. A scoring system was developed to estimate the 7-year ESRD risk from eight clinical and pathological variables. Actually, this prognostic score accurately classified patients by risk: patients with estimates of 0.0-0.9, 1.0-4.9, 5.0-19.9, 20.0-49.9, and 50.0-100.0% had a 0.2, 2.4, 12.2, 40.2 and 80.8% of ESRD incidence over 7 years, respectively. The corresponding area under the receiver operating characteristic curve was 0.939 [95% confidence interval (CI), 0.921-0.958]. This score was verified in repetitions of the derivation-validation technique. CONCLUSIONS: Although the quality of some data collected by the mail survey is limited and the influence of therapy could not be considered, this scoring system will serve as a useful prognostic tool for IgA nephropathy in clinical practice.

A family showing resistance to thyroid hormone associated with chronic thyroiditis and its clinical features: A case report.

Resistance to thyroid hormone (RTH) is characterized by decreased tissue responsiveness to thyroid hormone, due mainly to mutation of the thyroid hormone receptor (TR) beta gene. It has been reported that serum of patients with RTH lacks autoantibodies against thyroglobulin (Tg) and thyroid peroxidase (TPO), except in rare cases where there is co-occurrence of coincidental autoimmune thyroiditis. Here we describe the five-year medical history of a Japanese woman and her father with RTH and coincidental chronic thyroiditis. The woman, aged 28 years, was referred to our hospital because of suspected hyperthyroidism. She showed a normal level of TSH and elevated levels of free triiodothyronine (FT3) and free thyroxine (FT4). Anti-Tg and anti-TPO antibodies were slightly positive. Since RTH was suspected, her parents were investigated with informed consent. Her father showed elevated levels of TSH, FT3 and FT4, and was positive for both anti-Tg antibody and anti-TPO antibody. Her mother had hypothyroidism caused by chronic thyroiditis. Sequencing of the TR beta gene showed that the patient and her father had a codon 453 mutation resulting in a CCT (proline) to ACT (threonine) substitution. The patient gradually developed emotional disturbance, and was admitted to a psychiatry ward for two months, where she was treated with lorazepam and her condition improved. Her father, on the other hand, has been doing well for five years. The patient and the father showed different clinical courses, even though they carried the same mutation of the TR beta gene. The fact that the father showed an elevated TSH level, whereas the patient did not, was thought to be due to decreased thyroid function caused by chronic thyroiditis.

[Case of rheumatoid arthritis with various histological lesions of the kidney].

We experienced a case of rheumatoid arthritis with nephrotic syndrome. A renal biopsy specimen from this patient showed various renal histological changes. The patient was a 50-year-old man who was diagnosed as having rheumatoid arthritis in 1987. We performed a renal biopsy because he had persistent proteinuria from March in 2002. The renal biopsy specimen showed amyloid AA and P protein deposition in the glomeruli. Moreover mild mesangial proliferation was recognized. IgA-deposition in the mesangial area, and granular-deposition of IgG along the glomerular capillary wall were also observed. In electron microscopy, electron dense deposits were recognized in the mesangial area and subepithelium of the glomerular basement membrane. From these findings, we diagnosed amyloid nephropathy, IgA nephritis and membranous nephropathy. Renal biopsy of patients with RA is useful not only for precise diagnosis, but also for selection of the appropriate treatment.

[Clinical significance of IgM deposition in the mesangium and mesangial hypercellularity in adult minimal change nephrotic syndrome].

Minimal change nephrotic syndrome(MCNS) typically shows no abnormalities in light microscopy. However, there are some minor light microscopic abnormalities that are considered to be MCNS variants. In pediatric nephrology, some researchers have reported that IgM deposition in the mesangium and mesangial hypercellularity are related to the response to steroid therapy and the long-term course. However, it is not clear whether IgM deposition in the mesangium and mesangial hypercellularity is responsible for the clinical course or the steroid response of patients with adult MCNS. To investigate the clinical importance of IgM deposition in the mesangium and mesangial hypercellularity, clinical records, follow up data, and renal samples of 47 patients with MCNS were reviewed. We also compared the histological data with those of a normal control group (n = 5). In our study, the presence of mesangial IgM deposition did not predict the patient's clinical course or responsiveness to steroid therapy. Increase in the number of nuclei in the glomeruli and PAS-positive area also did not correlate with the clinical course or responsiveness to steroid therapy. The data suggest that mesangial IgM deposits and increased mesangial cellularity in adult MCNS may not predict the clinical course or steroid response. However, we investigated only 47 samples in this study, therefore, further studies are necessary to identify the importance of IgM deposition in the mesangium and mesangial hypercellularity in adult MCNS.

[Revised criteria for the early diagnosis of diabetic nephropathy].

The Diabetic Nephropathy Committee recommends the use of revised criteria for the early diagnosis of diabetic nephropathy in Japan. The new criteria are as follows: 1) Urinary albumin should be determined by immunoassay using a morning spot urine sample in diabetic patients without proteinuria or with dipstick-positive(+ 1) proteinuria. 2) A urinary albumin-to-creatinine ratio ranging from 30 to 299 mg/ gCr in 2 or more of 3 specimens may be diagnosed as microalbuminuria. 3) Two alternatives, i.e. the urinary albumin excretion rate of 30-299 mg/24hr in 24hr urine collection or 20-199 microg/min in timed urine collection can be used to detect microalbuminuria. 4) Renal hypertrophy and elevated urinary type IV collagen may indicate the existence of diabetic renal disease. 5) Microalbuminuria originating in non-diabetic diseases should be excluded.

[Methodology of retrospective chart review to detect adverse events: the reliability of physician judgment].

PURPOSE: To establish a scientific basis for promoting patient safety, basic information related to the incidence of adverse events (AEs) is needed. In studies in several other countries, trained nurses screened for potential AEs using explicit criteria in the first stage, and physicians reviewed selected charts in the second stage. To assure the accuracy of retrospective chart review, it is important to verify the reliability of AE judgments by physician reviewers. The purpose of this study was to test this reliability of judgment of AEs (their presence, causation of healthcare management and preventability) by three physician reviewers. METHODS: This study used 100 selected charts of non-psychiatric inpatients in an acute care hospital. Three physicians independently assessed AEs and discussed their judgments with the physician who created the manual for judging AEs. We considered judgments of the AEs agreed on by the four physicians to be final AE judgments and compared the reliability of each measure related to AE judgments among the physician reviewers using the kappa statistic. RESULTS: The number of AE cases each physician reviewer judged ranged from 18 to 27. Agreement on the presence of an AE ranged from 83.0% to 90.0% (kappa=0.52-0.70). Ultimately, AEs were judged to have occurred in 16 cases while 7 cases were deferred. The agreement on the presence of an AE between the physician's and the final judgment ranged from 86.0% to 96.8% (kappa = 0.56-0.88). However, agreement on the causation of healthcare management and preventability between the physician's and the final judgment was not in the acceptable range. CONCLUSION: The reliability of each physician's judgments regarding the presence of an AE was satisfactory. However, the reliability of judgments related to the causation of health care management and preventability was not necessarily satisfactory. Therefore, it is considered important to judge causation and preventability based on discussion with clinical experts in the relevant field.

Vascular endothelial growth factor gene expression is correlated with glomerular neovascularization in human diabetic nephropathy.

BACKGROUND: In diabetic nephropathy (DN) small vessels are frequently observed around the glomerular vascular pole in addition to normal afferent and efferent arterioles; this is regarded as neovascularization . Because vascular endothelial growth factor (VEGF) promotes vascular generation, the authors investigated the relationship between glomerular VEGF gene expression and structural glomerular changes in the early stage of human DN. METHODS: Kidney specimens were obtained from 18 type 2 DN patients by open renal biopsy. Additional vessels were distinguished by light microscopy as either afferent or efferent arterioles. Glomerular VEGF messenger RNA expression was determined by using in situ hybridization. The mesangial matrix area was quantified, and the ratio of the mesangial matrix area to the whole glomerular area was calculated to determine the mesangial matrix index (MMI). RESULTS: There were significantly more glomeruli with extra vessels in DN than in normal kidneys. The degree of neovascularization was significantly increased in DN and correlated with the magnitude of VEGF messenger RNA expression (r 2 = 0.46, P = 0.010) and MMI (r 2 = 0.45, P = 0.0093). CONCLUSION: These findings suggest that glomerular VEGF may be involved in structural changes in human DN at an early stage.

Tissue-specific expression of renin-angiotensin system components in IgA nephropathy.

BACKGROUND: The renin-angiotensin II system (RAS) has been implicated in the development of glomerulonephritis. The aims of this study were to determine (1) the expression of RAS components, angiotensin (Ang II)-forming enzymes [angiotensin-I-converting enzyme (ACE) and chymase], and Ang II receptors, and (2) the correlation between RAS expression and severity of tissue injury in IgA nephropathy (IgAN). METHODS: The expression levels of ACE, chymase, and Ang II type 1 and type 2 receptor (AT1R and AT2R) mRNAs were determined by in situ hybridization in renal specimens from 18 patients with IgAN, 5 patients with non-IgA mesangial proliferative glomerulonephritis (non-IgAN) and 10 patients with nonmesangial proliferative glomerulonephritis (minimal change nephrotic syndrome, n = 5, and membranous nephropathy, n = 5). Normal portions of surgically resected kidney served as control. RESULTS: In normal kidney, a few mesangial cells and glomerular and tubular epithelial cells weakly expressed ACE, chymase and AT1R mRNAs. In IgAN and non-IgAN samples, ACE, chymase, AT1R and AT2R mRNAs were expressed in resident glomerular cells, including mesangial cells, glomerular epithelial cells and cells of Bowman's capsule. The glomerular expressions in IgAN were stronger than in minimal change nephrotic syndrome and membranous nephropathy. In IgAN, the expressions in glomeruli correlated with the degree of mesangial hypercellularity, whereas the expression levels were weaker at the area of mesangial expansion. IgAN with severe tubulointerstitial injury showed expression of ACE, chymase, AT1R and AT2R mRNAs in atrophic tubules and infiltrating cells and such expression correlated with the degree of tubulointerstitial damage. CONCLUSION: Our results suggest that renal cells can produce RAS components and that locally synthesized Ang II may be involved in tissue injury in IgAN through Ang II receptors in the kidney.

Neutral-pH peritoneal dialysis solution improves peritoneal function and decreases matrix metalloproteinase-2 (MMP-2) in patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

BACKGROUND: Conventional lactate-buffered peritoneal dialysis (PD) solutions have several bioincompatible characteristics, including acidic pH, lactate buffer, and the presence of glucose degradation products (GDPs), and these characteristics contribute to membrane dysfunction in PD patients. The formation of GDPs can be reduced by separating the glucose component of the solution from the lactate component during sterilization. This study was carried out to evaluate the clinical effect of dual-chambered neutral-pH PD solution in patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: Thirteen CAPD patients using conventional PD solution were enrolled in this study. The fast peritoneal equilibration test (fast PET) was performed periodically before and after treatment with neutral PD solution. The concentration of matrix metalloproteinase-2 (MMP-2) in dialysate effluent was measured using 4-h dwelling 2.5% glucose dialysis solution. The patients were categorized into two groups, according to the value of the initial dialysate/plasma (D/P) creatinine ratio: i.e., lower transporters (group L, D/PCr < 0.65) and higher transporters (group H, D/PCr >/= 0.65). RESULTS: The mean D/P creatinine ratio measured by fast PET, was significantly decreased (0.72 +/- 0.09 to 0.60 +/- 0.06; P < 0.03) after treatment with neutral PD solution in group H. The mean glucose level in 4-h dwelling dialysate effluent was elevated (824.6 +/- 195.9 mg/dl to 942.6 +/- 147.8 mg/dl; P < 0.022) in all subjects. In group H, a significant decrease of MMP-2 in the dialysate effluent was recognized from 15 months after the beginning of treatment with the neutral PD solution (141.4 +/- 52.5 ng/ml to 91.3 +/- 15.1 ng/ml; P < 0.05), with the lowest value being shown at 21 months (80.0 +/- 31.8 ng/ml; P < 0.03). CONCLUSIONS: Neutral-pH peritoneal dialysis solution decreased the MMP-2 level in dialysate and improved peritoneal function in high-transporter patients with CAPD treatment.

Antiproteinuric effect of candesartan cilexetil in Japanese subjects with type 2 diabetes and nephropathy.

The effect of the angiotensin II receptor blocker, candesartan cilexetil, on proteinuria was examined in a prospective, multicenter, randomized, double-blind study in Japanese subjects with type 2 diabetes. This study enrolled diabetic subjects with confirmed proteinuria into four groups for 12 weeks of treatment with placebo or candesartan cilexetil 2, 4, or 8 mg. The contribution of the angiotensin converting enzyme (ACE) gene polymorphism to the effect of candesartan cilexetil was also examined. In 127 subjects, candesartan cilexetil showed a dose-related reduction in proteinuria after 12 weeks of treatment (F = 9.45, P = 0.0013), with a 18.1% reduction in the 4-mg group, and a 5.8% reduction in the 8-mg group, in contrast to a 32.2% increase in the placebo group, and a 0.8% increase in the 2-mg group. These results indicate that candesartan cilexetil is useful in reducing proteinuria in diabetic subjects when compared with placebo. In addition, candesartan cilexetil seems to be effective in subjects with both the II and DD genotypes of the ACE gene.

High expression of PKC-MAPK pathway mRNAs correlates with glomerular lesions in human diabetic nephropathy.

BACKGROUND: Activation of protein kinase C (PKC) is a major signaling pathway for transforming growth factor (TGF)-beta to induce extracellular matrix (ECM) production in diabetic nephropathy (DN). PKC also activates mitogen-activated protein kinase (MAPK), which is called the PKC-MAPK pathway. The PKC-MAPK pathway is probably responsible for PKC-related abnormalities in diabetic glomeruli. To confirm the involvement of this pathway, we determined the localization and expression of mRNAs in glomeruli by in situ hybridization method. METHODS: In the present study, we examined expression of PKCbeta1, MAPK/ERK kinase (MEK) 1, MEK2, extracellular signal-regulated protein kinase (ERK) 1, ERK2, and TGF-beta1 mRNAs using renal tissue samples from kidneys affected by DN (N= 21) and from normal human kidney (NHK; N= 6). We also performed an immunohistochemical study using anti-phosphorylated MEK1/2 (P-MEK) and ERK1/2 (P-ERK) antibodies. The glomerular severity of DN was classified into three groups according to mesangial expansion: D1 (N= 4), D2 (N= 13), and D3 (N= 4). We analyzed differences and correlations between variables. RESULTS: In the glomeruli, the number of cells that stained for these mRNAs in DN was significantly higher than in NHK. The expression of PKC-MAPK pathway mRNAs tended to be inversely proportional to the degree of mesangial expansion. The P-MEK and P-ERK signal intensity were parallel to its mRNA expression pattern. Furthermore, there were significant correlations among the P-MEK, P-ERK signal intensity, PKCbeta1 mRNA expression. CONCLUSION: Our results suggest that high expression of PKC-MAPK pathway mRNAs plays an important role in the development and/or progression of early tissue damage in DN.

[Incidentaloma of the thyroid].

Thyroid incidentalomas are common, often less than 1.5 cm in size, and frequently benign. It is recommended that low-risk patients with incidentalomas be followed up ultrasonographically in 6 to 12 months and not be subjected to routine testing with ultrasonographically guided fine-needle aspiration biopsy (US-FNA). In patients who have nodules larger than 1.5 cm in size, a history of head and neck irradiation, a strong family history of thyroid carcinoma, or ultrasonographic findings that suggest malignancy, US-FNA should be done. A patient with hypercalcemia caused by ectopic production of parathyroid hormone in papillary thyroid carcinoma was reported. It is known that medullary thyroid carcinoma rarely shows production of adrenocorticotropic hormone or serotonin. However, ectopic hormone productive tumors in the thyroid are extremely rare.

Prognosis and risk factors for idiopathic membranous nephropathy with nephrotic syndrome in Japan.

BACKGROUND: Idiopathic membranous nephropathy (IMN) is a representative form of refractory nephrotic syndrome in Japan. Although IMN is thought to run a more benign course in Japanese than in the Caucasian population, risk factors and appropriate treatment are controversial issues. METHODS: The research group supported by a grant for "Progressive Renal Disease" from the Ministry of Health, Labor and Welfare, Japan, carried out a national survey of patients with IMN and nephrotic syndrome. Of 1066 nephrotic patients with histopathologically proven IMN registered from 1975 to 1993 in 85 institutions, 949 patients were studied. RESULTS: The overall renal survival rates were 95.8%, 90.3%, 81.1%, and 60.5% at 5, 10, 15, and 20 years after diagnosis, respectively. When clinical and histopathologic features at onset of nephrotic syndrome were evaluated by multivariate analysis, male gender, old age (> or =60 years), high serum creatinine concentration (> or =1.5 mg/dL), and the development of tubulointerstitial lesions (> or =20% of the biopsy sample area) were significant predictors of progression to end-stage renal disease (ESRD). The renal survival rate in patients on steroid therapy was significantly higher than in patients on supportive therapy alone. Patients achieving a remission showed a significant reduction of risk for progression. CONCLUSION: IMN is a disease with a comparatively good prognosis in Japan even when it is associated with nephrotic syndrome. Steroid therapy, which has not been recommended for IMN in most review articles, seems to be useful at least for Japanese patients. In particular, a remission from heavy proteinuria likely results in a favorable outcome.

Glomerular expression of platelet-derived growth factor (PDGF)-A, -B chain and PDGF receptor-alpha, -beta in human diabetic nephropathy.

BACKGROUND: Mesangial expansion is thought to be a major cause of diabetic nephropathy (DN). Platelet-derived growth factor (PDGF) plays an important role in the production of extracellular matrix proteins in renal diseases. The present study was designed to determine the expression of PDGF and PDF receptor (PDGFR) mRNA in the renal tissues of type 2 diabetic patients with DN. METHODS: We examined open renal biopsies of 20 type 2 diabetic patients with DN, and 10 normal human kidneys (NHK). Histopathologically, the severity of DN was classified as grade I (DN I, n = 10; mild mesangial expansion) or grade II (DN II, n = 10; moderate mesangial expansion). We evaluated the expression and localization of PDGF-A, -B, and PDGFR-Alpha, -Beta using in situ hybridization, and quantified PDGF and PDGFR mRNA expression by counting all nuclei, and nuclei surrounded by PDGF-positive cytoplasm and PDGFR-positive cytoplasm, in at least ten randomly selected cross-sections of nonsclerotic glomeruli. RESULTS: In all glomeruli, PDGF and PDGFR mRNAs were expressed mainly in glomerular resident cells, predominantly glomerular mesangial and epithelial cells. The percentages of cells positive for PDGF-A and PDGFR-Alpha mRNA in DN were similar to those in NHK. In contrast, the percentages of PDGF-B and PDGFR-Beta mRNA-positive cells in DN were significantly higher than those in NHK, and were significantly higher in DN I than in DN II: The percentages of cells positive for PDGF-B correlated with the PDGFR-Beta mRNA level. CONCLUSIONS: Our results suggest that the expression of PDGF-B and PDGFR-Beta is an important factor in histologically early glomerular lesions of DN. Mesangial expansion is thought to be a major cause of diabetic nephropathy (DN). Platelet-derived growth factor (PDGF) plays an important role in the production of extracellular matrix proteins in renal diseases. The present study was designed to determine the expression of PDGF and PDGF receptor (PDGFR) mRNA in the renal tissues of type 2 diabetic patients with DN.

Clinical significance of costimulatory molecules CD80/CD86 expression in IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is the most common form of human glomerulonephritis. Tubulointerstitial inflammation with infiltration of mononuclear cells plays an important role in the progression of IgAN. Activation of T cells requires costimulatory signals through binding of CD28 receptor with cognate ligands (CD80/CD86) located on antigen-presenting cells (APC). To assess the clinical significance of this regulatory pathway participation in the pathogenesis of IgAN, a comprehensive immunohistologic evaluation was conducted on renal tissue of IgAN in different phases of progressive injury. METHODS: Thirty-three cases of IgAN and ten cases of non-IgA mesangial proliferative glomerulonephritis (PGN) with minor tissue damage as controls were investigated. Monoclonal antibodies were used to assess the expression of CD80, CD86, CD68, CD14, CD45RO, human leukocyte antigen-DR (HLA-DR), and intercellular adhesion molecule-1 (ICAM-1) in renal tissues. Clinical and expression data were compared at the time of renal biopsy. RESULTS: CD80+ and CD86+ cells were observed more in IgAN patients with progressive renal injury than in mild cases and controls. CD80 was limited to tubular epithelial cells and was complemented by HLA-DR expression. CD86 was expressed in the glomerulus, periglomerular area, and peritubular interstitium. Activated T cells (CD45RO+), monocytes (CD14+), macrophages (CD68+), and CD86 showed similar distributions. Positive correlations were found between CD86+ cells and CD45RO, CD14, and CD68 positive cells and between CD80+ tubuli and peritubular interstitial CD45RO+ cells. The number of interstitial CD86 positive cells and the percentage of CD80+ tubuli were correlated with renal function. Most CD86+ cells were monocyte/macrophages. CONCLUSION: This study suggested that CD80 and CD86 activate T cells in IgAN, CD80/CD86 expressions correlated with renal function at the time of renal biopsy, and monocyte/macrophages and tubular epithelial cells act as APC.

Expression of human nephrin mRNA in diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is associated with functional changes in the filtration barrier, and microalbuminuria is a strong predictor of the development of overt DN. Nephrin is a novel podocyte-specific protein which localizes at the slit diaphragm. This study examines the expression of nephrin mRNA in the kidneys of type 2 diabetics with DN. METHODS: Renal tissues were obtained from 13 type 2 diabetics with DN. We also examined samples from five patients with minimal change nephrotic syndrome (MCNS) and five normal kidneys (normals) as control. The severity of DN was classified into two grades based on histopathological findings. DN grade 1 (DN1 = seven patients) presented mild mesangial expansion, and DN grade 2 (DN2 = six patients) moderate mesangial expansion. Nephrin mRNA was quantitated and localized by in situ hybridization. RESULTS: Cells positive for nephrin mRNA were detected exclusively in glomerular epithelial cells. The percentage of cells positive for nephrin mRNA in DN2 was significantly lower than in MCNS and normal kidneys. Furthermore, there was an inverse correlation between the percentage of cells positive for nephrin mRNA and extent of proteinuria. CONCLUSION: The low expression of nephrin mRNA may be closely linked to development and/or progression of proteinuria in human diabetic nephropathy.

Clinical guidelines for immunoglobulin A (IgA) nephropathy in Japan, second version.

In 1995, clinical guidelines for the diagnosis and treatment of patients with immunoglobulin A (IgA) nephropathy in Japan were published by a joint committee of the Special Study Group on Progressive Glomerular Disease, Ministry of Health and Welfare of Japan (Chairman, Kiyoshi Kurokawa, MD), and the Japanese Society of Nephrology (President, Toshihiko Nagasawa, MD). The purpose of this new committee of the Special Study Group on Progressive Glomerular Disease, Ministry of Health and Welfare of Japan (Chairman, Hideto Sakai, MD), is to provide new clinical guidelines for the diagnosis and treatment of patients with IgA nephropathy in Japan. Although this document addresses current clinical practice in Japan, it is hoped that this English version will be helpful to the international community and will facilitate further discussion on this increasingly important disease.