High molecular weight adiponectin inhibits vascular calcification in renal allograft recipients.

BACKGROUND: Adiponectin (ADPN) prevents the development/recurrence of cardiovascular events via its anti-atherogenic effects. However, few long-term studies have examined the changes in serum ADPN levels and arterial calcification seen in renal allograft recipients. SUBJECTS AND METHODS: The effects of the serum ADPN level on arterial calcification were examined in 51 Japanese renal allograft recipients. Abdominal aorta calcification was evaluated on computed tomography using the aortic calcification area index (ACAI). The change in the ACAI and serum high-molecular-weight (HMW)-ADPN fractions were studied over an 8-year period. The arterial expression of ADPN, ADPN receptors (AdipoR)1 and 2, and T-cadherin (cadherin-13) were also examined by immunohistochemistry. RESULTS: The change in the ACAI were grouped into quartiles and compared with the alterations in the serum levels of each ADPN fraction over an 8-year period. The change in the ACAI was much lower in the patients with highly elevated HMW-ADPN levels.Multiple regression analysis demonstrated that an advanced age at transplant and a history of cardiovascular complications were associated with an increased change in the ACAI, while higher HMW-ADPN concentrations were associated with improvements in the ACAI. Serum HDL-C level was also identified as a positive factor to increase serum HMW-ADPN level.In immunohistochemical examinations, ADPN was detected on CD31-positive arterial endothelial cells from renal allograft biopsy samples. ADPN co-localized with T-cadherin and AdipoR1, but only partially co-localized with AdipoR2. CONCLUSION: Both HMW-ADPN and HDL-C might inhibit the progression of vascular calcification by promoting ADPN binding to vascular endothelial cells via T-cadherin and AdipoR in Japanese renal allograft recipients.

Glomerular mannose-binding lectin deposition in intrinsic antigen-related membranous nephropathy.

Background: The M-type phospholipase A2 receptor (PLA2R) and thrombospondin type-1 domain-containing 7A (THSD7A) were identified as intrinsic antigens in primary membranous nephropathy (MN). Complement activation via the lectin pathway in intrinsic antigen-related MN is still unclear. Methods: We retrospectively enrolled 60 primary Japanese MN patients and detected activated complement pathways by staining complement proteins in glomerular deposition. According to the findings of PLA2R and THSD7A staining in glomeruli, they were classified into intrinsic antigen-related or -unrelated MN. We evaluated clinicopathological characteristics and predictors of clinical outcomes in intrinsic antigen-related MN. Results: Thirty-nine (65%) patients had PLA2R in glomerular deposits and two (3.3%) patients had THSD7A. One of them had both PLA2R and THSD7A (double positive). Forty patients were classified into the intrinsic antigen-related group. The other 20 patients were negative for both antigens (unrelated group). The prevalence and staining intensity of mannose-binding lectin (MBL) deposits were much higher in the intrinsic antigen-related group [55% versus 20%, P < 0.010, 1.0 (interquartile range 1.0-2.0) versus 1.0 (0.0-1.0), P = 0.01, respectively]. The staining intensity of MBL in glomeruli also correlated with the IgG4 staining intensity. In intrinsic antigen-related MN, MBL staining intensity was an unfavorable predictor for remission of proteinuria [hazard ratio (HR) 0.40, P < 0.01] and renal dysfunction (HR 3.81, P = 0.01) in Cox proportional hazards analysis. Moreover, the glomerular MBL-positive group showed more severe interstitial fibrosis and worse clinical outcomes. Conclusions: Intrinsic antigen-related MN was more strongly associated with complement activation by the lectin pathway, which may contribute to a less favorable clinical outcome.

Circulating and renal expression of HLA-G prevented chronic renal allograft dysfunction in Japanese recipients.

BACKGROUND: Although the risk of acute rejection has been studied in renal transplanted patients, there is little data about the long-term renal survival effects of non-classical human leukocyte antigen class I (HLA-G) in Japanese patients. METHOD: We investigated the changes in the estimated glomerular filtration rate (eGFR) for Japanese, and factors affecting the eGFR in 141 adult Japanese subjects whose allografts had survived for at least 1 year. Clinical background data, gender, HLA matching status, the total ischemic time, ABO incompatibility, immunosuppressive therapy, and the serum soluble(s) HLA-G5 level were examined. In addition, renal biopsy specimens from 32 cases, which were obtained before, or 2-4 weeks or one year after the transplant were also evaluated for HLA-G1/5 expression using monoclonal anti-HLA-G antibodies (clone 87G or 4H84). RESULTS: The rates of change per year in the median eGFR (ΔeGFR) and sHLA-G5 were -1.5 ml/min/1.73 m2/year and 11.8 ng/ml, respectively. A positive correlation was detected between the ΔeGFR and sHLA-G5 (r = 0.188, p = 0.025). In multivariate regression analysis, sHLA-G5 and HLA-matching were significant predictors of an improvement in eGFR (beta for sHLA-G: 0.374, p = 0.009; beta for mismatching: -1.135, p = 0.045). The renal tubular epithelial cells (TEC) in 11 cases showed a perinuclear HLA-G1/5 expression after renal transplantation. The renal HLA-G1/5-positive patients displayed much better ΔeGFR (p < 0.05). In conclusion, the sHLA-G5 level and HLA matching status are independent predictors of renal allograft function, as determined by the ΔeGFR, in Japanese patients. HLA-G1/5 was also detected on TEC in the patients with favorable renal function.

The long-term outcomes of hepatitis C virus core antigen-positive Japanese renal allograft recipients.

BACKGROUND: The impact of hepatitis C virus (HCV) infections on patient long-term survival after renal transplants is unclear. METHOD: To clarify the long-term outcomes of Japanese renal allograft recipients with HCV infections, we studied the cases of 187 patients (118 males and 69 females; 155 living donor cases, and 32 deceased donor cases; median follow-up period: 250 months) who underwent an initial renal transplant at Kanazawa Medical University from 1974 onwards. RESULT: In this cohort, 35 patients (18.7%) were HCV core antigen (Ag)-positive, and 13 of them (37.1%) died (due to liver cirrhosis (4 cases), hepatocellular carcinoma (1 case), fibrosing cholestatic hepatitis due to HCV (1 case), and infections complicated with chronic hepatitis (6 cases)). However, only 14 of the 145 (9.7%) recipients died in the HCV-Ag/HCV antibody (Ab)-negative group. The Kaplan-Meier life table method indicated that the HCV-infected group exhibited significantly lower patient and death-censored allograft survival rates (log-rank test; patient survival: Chi-square: 11.2, p = 0.004; graft survival: Chi-square: 25.7, p < 0.001). The survival rate of the HCV-Ag-positive recipients decreased rapidly at 240 months after the renal transplant procedure. In addition, a Cox proportional hazards model indicated that positivity for the HCV-Ag was the most important independent risk factor for post-renal transplant survival and allograft function [survival: hazard ratio (HR) 3.93 (1.54-10.03), p = 0.004; graft function: HR 2.09 (1.14-3.81), p = 0.016]. CONCLUSION: HCV infection is a harmful risk factor for patient survival (especially at ≥20 years post-renal transplant) and renal allograft function in allograft recipients.

Adiponectin Fractions Influence the Development of Posttransplant Diabetes Mellitus and Cardiovascular Disease in Japanese Renal Transplant Recipients.

BACKGROUND: A few studies have investigated the role of adiponectin fraction for cardiovascular disease (CVD) in RTx recipients. SUBJECTS AND METHODS: We studied 57 adult subjects (39 males, 18 females; 10 cadaveric donors) with at least three years of allograft survival (median 251 months). We examined clinical backgrounds such as treated drugs, blood pressure (BP, mmHg), body mass index (BMI), and blood chemistry including cholesterol (total, LDL-C, HDL-C), glucose, glycated hemoglobin (HbA1c), and serum high and low-molecular-weight (HMW/LMW) ADPN fractions with regard to the associations of the visceral and subcutaneous fat areas on CT scan. We also analyzed the associations of CVD and post-transplant diabetes (PTDM) with ADPN fractions and the fat areas. RESULTS: The visceral fat area was inversely correlated with serum HMW and LMW ADPN levels and HMW ADPN ratio (r = -0.400, p = 0.002 and r = -0.296, p = 0.025 and r = -0.444, p<0.001, respectively). Furthermore, the visceral fat area was positively with the LMW ADPN ratio (r = 0.467, p<0.001), but no significant correlation was noted between the subcutaneous fat area and the ADPN ratio. On multiple regression analysis, eGFR and the visceral fat area were significant reducing factors of HMW ADPN levels, and the alteration of eGFR was identified as an increasing factor of HMW ADPN levels. Patients with CVD had larger visceral fat area (p = 0.004), lower HMW ADPN ratio (p = 0.022) and higher LMW ADPN ratio (p = 0.049). In addition, the higher HMW ADPN ratio and statin treatment were identified as reducing factors of the development of CVD, but the LDL-C level was an aggravating factor. Moreover, the higher LMW ADPN ratio and the visceral fat area were aggravating factors of PTDM. CONCLUSION: Even in Japanese renal transplant recipients, visceral fat area and ADPN fractions were significant factors for the development of both CVD and PTDM.

Regulation of soluble Flt-1 (VEGFR-1) production by hnRNP D and protein arginine methylation.

Soluble fms-like tyrosine kinase-1 (sFlt-1) functions as a potent inhibitor of angiogenesis by trapping vascular endothelial growth factor (VEGF). However, the precise regulatory mechanism of sFlt-1 production is unknown. Here, we report that vascular sFlt-1 production is regulated by heterogeneous nuclear ribonucleoprotein D (hnRNP D) and arginine methylation. We showed that hnRNP D bound to Flt-1 pre-mRNA and that hnRNP D overexpression decreased sFlt-1 mRNA in human microvascular endothelial cells (HMVECs). In contrast, the reduction of hnRNP D levels induced an increase in sFlt-1 production. Overexpression of an hnRNP D mutant in which the arginine residue of the known arginine methylation motif (arginine-glycine-glycine; RGG) was replaced with alanine did not reduce the level of soluble-form RNA produced from the Flt-1 minigene. Moreover, we demonstrated that overexpression of arginine methyltransferase decreased the soluble-form RNA level, whereas overexpression of arginine demethylase and addition of methyltransferase inhibitors increased sFlt-1 mRNA levels. These findings indicate that hnRNP D and arginine methylation play important roles in the regulation of Flt-1 mRNA alternative polyadenylation.

DNA double-strand breaks induced intractable glomerular fibrosis in renal allografts.

BACKGROUNDS: The relationship between DNA damage and glomerular fibrosis in renal allografts remains unclear. METHODS: We examined renal allograft specimens from 35 patients in which DNA double-strand breaks (DSBs) and glomerular fibrosis were detected by phospho-histone H2A.X (γ-H2AX) expression and collagen (COL) types III, IV, and VI accumulation. We also examined the in vitro relationship between DNA damage and COL accumulation by mitomycin C (MMc)-induced DNA damage in human glomerular endothelial cells (HRGEc). RESULTS: The γ-H2AX and COL type VI, which mainly accumulated in the subendothelial and mesangial regions, were positively correlated with the duration of the post-renal transplant (RT) period. In multiple regression analysis, the duration of the post-RT period and cg in the Banff '07 classification were identified as a significant predictor of COL type VI accumulation and γ-H2AX expression in the glomerular capillaries. In addition, the γ-H2AX-positive area was also identified as a predictor of glomerular accumulation of COL type VI. COL type VI was detected in the cytoplasm of the HRGEc, which was secreted into the supernatant after MMc stimulation with γ-H2AX expression. The number of γ-H2AX (-)/COL type VI (+) cells was inversely associated with the number of γ-H2AX (+)/COL type VI (-) cells during 24-h MMc treatment. CONCLUSIONS: Our findings suggest that the long-term RT induces DSBs and HRGEc-secreted COL type VI accumulation in the glomerular capillaries, which might progress to intractable glomerular fibrosis.

A case of IgG4-related kidney disease complicated by eosinophilic lung disease.

IgG4-related disease is a systemic chronic inflammatory disorder characterized by a high blood level of IgG4 and the organ injuries by marked infiltration of IgG4-positive plasma cells and fibrosis. A 71-year-old male was hospitalized for a cough, malaise and anorexia. IgG4-related disease was suspected due to marked elevation of the serum IgG4 level. However, on lung biopsy, only eosinophil infiltration was demonstrated with no plasma cell infiltration. Otherwise abdominal contrast-enhanced CT showed mild enlargement of the bilateral kidneys and many differed contrasted areas and FDG PET-CT. Moreover, renal biopsy specimens showed typical tubulointerstitial nephritis with a large number of IgG4-positive plasma cells infiltration (the IgG4/IgG-positive cell rate, 89 %) and fibrosis. We diagnosed this patient as typical IgG4-related kidney disease. He was treated by the moderate dose of prednisolone (0.8 mg/kg/day) alone, and showed prompt response in the clinical condition, and both the lung and kidney lesions. In this case, it was useful for diagnosis of IgG4-related diseases to evaluate an image such as abdominal contrast-enhanced CT and FDG PET-CT. Our case might be one of the possible patterns of IgG4-related lung diseases. In addition, we thought that there might be an association between hypereosinophilia and IgG4-related kidney disease.

Clinicopathological characteristics of M-type phospholipase A2 receptor (PLA2R)-related membranous nephropathy in Japanese.

BACKGROUND: Recent studies have suggested that assessments of serum antibodies against M-type phospholipase A2 receptor (PLA2R) and the glomerular expression of PLA2R antigen in biopsy specimens are useful for the diagnosis of primary membranous nephropathy (MN). In this study, we assessed both of them and investigated the clinicopathological characteristics of PLA2R-related Japanese MN. METHODS: We retrospectively enrolled 22 primary and 3 secondary Japanese patients whose serum samples and renal specimens were collected before treatment. According to the findings of serum antibodies and antigen in glomeruli, the primary MN patients were classified into PLA2R-related or -unrelated MN. We compared their clinicopathological findings, including IgG subclass staining, and electron microscopic findings, and evaluated the predictors of proteinuria remission. RESULTS: In primary MN, 16 patients (73 %) were classified into the PLA2R-related group, and 6 patients into the PLA2R-unrelated group. There was no significant difference in baseline laboratory data and electron microscopic findings, except for eGFR and serum IgG levels. IgG4-dominant deposition was more common in the related group (63 vs. 0 %). The 10 PLA2R-related patients with dominant IgG4 deposition had a lower rate and prolonged time in remission compared with the 6 PLA2R-related patients with non-dominant IgG4 (log-rank, p = 0.032). Furthermore, dominant IgG4 deposition was an unfavorable predictor of remission by multivariable Cox proportional hazard analysis. CONCLUSIONS: Assessments of both serum PLA2R antibodies and PLA2R antigen in glomeruli were more sensitive for the diagnosis of PLA2R-related MN, and among affected Japanese patients, those with dominant IgG4 deposition had worse clinical outcomes.

Clinical significance of serum and urinary soluble urokinase receptor (suPAR) in primary nephrotic syndrome and MPO-ANCA-associated glomerulonephritis in Japanese.

BACKGROUND: The soluble urokinase receptor (suPAR) has been implicated as a cause of primary focal segmental glomerulosclerosis (FSGS). However, the clinical significance of suPAR in glomerular diseases currently remains unclear. METHODS: In this retrospective single-center cohort study, we investigated serum (s-) and urinary (u-) suPAR in patients with primary nephrotic syndrome (NS) (serum/urine: 37/32 cases) and MPO-ANCA-associated glomerulonephritis (ANCA-GN) (serum/urine: 13/11 cases). RESULTS: In pretreatment s- and u-suPAR, no significant differences were observed between the primary NS and ANCA-GN groups or among the pathological types of primary NS. An inverse correlation was noted between pretreatment s-suPAR and eGFR in the primary NS and ANCA-GN groups. A positive correlation was noted between pretreatment u-suPAR and proteinuria in the primary NS group. Furthermore, time-course changes in s- and u-suPAR over 2 months after therapy were associated with the therapeutic responsiveness of primary NS, particularly the differentiation of MCNS from FSGS (s-suPAR: AUC-ROC = 0.905, p = 0.007; u-suPAR: AUC-ROC = 0.816, p = 0.048). In the ANCA-GN group, a positive correlation was found between pretreatment s-suPAR and clinical severity or crescent formation, whereas u-suPAR was not correlated with these parameters. CONCLUSION: S- and u-suPAR after therapy may serve as clinical markers to judge the treatment response of untreated NS and differentiate MCNS from FSGS, but not in pretreatment patients. S-, but not u-suPAR may predict the severity of and crescent formation in ANCA-GN.

A patient with persistent renal AL amyloid deposition after clinical remission by HDM/SCT therapy.

A 62-year-old female patient was admitted to our hospital for evaluation of nephrotic syndrome. Monoclonal gammopathy (IgG λ type) and urinary Bence Jones proteins were detected in the serum and urine by the immunofixation method. The initial renal biopsy revealed amyloid deposition in mesangial area, glomerular capillary walls and arterioles by Congo-red staining, and amyloid fibers were detected by electron microscopy. On the bone marrow test, plasma cells accounted for 8.6%. Based on these findings, we diagnosed as AL amyloidosis associated with multiple myeloma. We treated her by high-dose intravenous injection therapy of melphalan combined with autologous peripheral blood stem cell transplantation. She achieved complete hematologic response 27 months later, however. Urine M-protein disappeared 2 months after treatment, and proteinuria slowly disappeared 17 months after treatment. On the other hand, amyloid fibers remained in renal biopsied tissues at 17 and 53 months after therapy. Electron microscopic examination also revealed the similar amyloid fibers in glomeruli. These findings suggest that, in this case, immunoglobulin light chains may cause directly and/or indirectly glomerular epithelial injury and nephrotic range proteinuria rather than via amyloid fiber formation.

Adult-onset renal failure in a family with Alagille syndrome with proteinuria and a novel JAG1 mutation.

Alagille syndrome (AGS) is an autosomal-dominant multi-organ disorder involving the liver, heart, eyes, face and skeleton. In addition, various renal abnormalities have also been reported in several cases. We describe a patient with a novel frameshift mutation in exon 12 of the JAG1 gene who presented with chronic renal failure. In this family, five members of three generations had clinical features implicated in AGS. Three members had adult-onset renal dysfunction with proteinuria, and two of them required haemodialysis therapy. AGS should be considered in the differential diagnosis of proteinuric renal disease, even in adult patients.

Circulating fibrocytes in ischemia-reperfusion injury and chronic renal allograft fibrosis.

BACKGROUND: Interstitial fibrosis in chronic allograft injury has been suggested as a major cause of the loss of allograft. METHODS: To clarify the involvement of circulating fibrocytes (CF) and α-smooth muscle actin (SMA)-positive cells in renal allograft injury, we investigated 36 renal transplanted cases at 0 h, 1 h, 2-4 weeks, 4-8 weeks, and 1 year, and 5 normal controls. Double immunofluorescence analysis for both COL1 and CD45 indicating CF (/mm(2)), and the positive area (%) of α-SMA and Masson trichrome (MT) stain were detected by an image analyzing system. RESULTS: The mean number of CF was 0 in controls and 4.0 in total transplanted specimens (p < 0.05). CF correlated with the α-SMA-positive area in the graft (R(2) = 0.39, p < 0.01), but not with Banff 2005 scores. The number of CF increased in 2-4 weeks; however, decreased 1 year after transplantation. α-SMA-positive area gradually increased at 1 year concomitant with the increase of MT-positive area. A similar phenomenon was observed in a case of primary nonfunction kidney from 0 h to 6 weeks after transplantation. The electron microscopy score of fibrosis around peritubular capillaries was correlated positively with COL1-positive area (R(2) = 0.72, p < 0.01), but negatively with infiltrated CF (R(2) = 0.25, p < 0.05). CONCLUSION: CF were transiently induced, probably due to ischemia-reperfusion injury, but fibrosis only slightly progressed in this process. The α-SMA-positive myofibroblasts may accelerate the expansion of fibrosis around peritubular capillaries in chronic allograft injury.

A case of chronic hepatitis C with nephrotic diabetic nephropathy who achieved sustained viral remission by double-filtration plasmapheresis and interferon combination therapy.

We report a 66-year-old man with chronic hepatitis caused by hepatitis type C virus of genotype-1b and high-viral-load combined with cryoglobulinemia and advanced diabetic nephropathy in whom we successfully achieved viral removal and eradication by DFPP (VRAD). The dose of PEG-interferon was reduced to 70 mg/week due to thrombocytopenia. Rivavirin was discontinued at day 21 due to anemia. Even with treatment of PEG-interferon alone, the condition was judged to be sustained viral remission at the end of the observation. This is a successful report of VRAD in a combined case of diabetic and HCV-related cryoglobulin-nephropathy with nephrotic syndrome. The therapeutic effect of IFN seemed to be efficiently enhanced by concomitant DFPP (VRAD therapy).

Clinicopathological insights into lupus glomerulonephritis in Japanese and Asians.

Lupus nephritis comprises a spectrum of glomerular, vascular, and tubulointerstitial lesions, which has significant racial variation in severity and manifestations. The current classification (ISN/RPS 2003) has been improved successfully for the categorization of lupus glomerulonephritis (LGN). On the basis of this classification, 480 Japanese cases revealed the following distribution: class I 3%, class II 16%, class III 13%, class IV-S 11%, class IV-G 41%, class V 16%, and class VI 1%. Class IV-G with chronicity tended to have the worst renal outcome. Nephrotic syndrome was a more frequent complication in class IV-S (50%), class IV-G (72%), and class V (56%), with poor renal and actuarial outcomes. With regard to therapy, treatment options including glucocorticoids alone or combined with antimetabolites (azathioprine, mizoribine, mycophenolate mofetil), calcineurin inhibitors (cyclosporine A, tacrolimus), or alkylating agents (intravenous cyclophosphamide injection) improved the outcome of LGN; however, there is no high-grade clinical evidence from Japan. Further studies are needed to resolve the clinicopathological problems of LGN, especially IV-S, IV-G, and pure membranous lupus nephritis in Japanese patients.

A case of second renal transplantation with acute antibody-mediated rejection complicated with BK virus nephropathy.

We reported a 40-year-old female case of second renal transplantation with antibody-mediated rejection (AMR) complicated by BK virus nephropathy. She started hemodialysis (HD) at the age of 17 because of IgA nephropathy. At the age of 18, she underwent living-donor kidney transplantation from her father, but two and a half years after transplantation, she developed chronic rejection. This time, she received cadaveric renal transplantation under the negative cross-match (AHG-LCT), and HLA-AB 1 mismatch and -DR 1 mismatch. Immunosuppressive therapy was initiated using the following four immunosuppressants: methylprednisolone, mycophenolate mofetil, cyclosporine, and basiliximab. However, renal graft showed delayed function, the biopsy showed glomerulitis (g2), endarteritis (v1), and cellular infiltration (ptc3) consisting mainly of mononuclear cells in the peritubular capillary with diffusely positive C4d and anti-SV 40 large T-antigen-positive renal tubular epithelial cells on post-operative day 19. The donor-specific antibody for HLA-B46 was proven by the LAB screen method. We performed plasma exchange three times and administered immunoglobulin (15 g in total). Then, methylprednisolone pulse therapy was added, and the serum creatinine (SCr) levels gradually decreased. On post-operative day 44, the patient was removed from HD and was discharged with SCr level of 3.3 mg/dL.

[Relationship between initial diagnosis and long-term prognosis in lupus nephritis].

UNLABELLED: To clarify the outcomes of patients with lupus glomerulonephritis (LGN), we performed a retrospective study of 31 patients (27 females and 4 males) with LGN between January 1975 and June 2006. All these 31 patients fulfilled the SLE criteria of the American College of Rheumatology evaluated by pathohistological diagnosis using renal biopsies. According to 2003 ISN/RPS classification, we reclassified all initial renal biopsies as class II 16%, class III 16%, class IV 48%, and class V 19.5%. Activity and chronicity indices were also calculated according to the scores proposed by Austin et al. All patients were treated by oral corticosteroids in induction therapy, then subsequeatly 18 patients (61%) were treated with intravenous methylprednisolone pulse therapy, and 16 patients with immunosuppressive agents (58%). Clinical remission rate was 94% by induction therapy and 13% by recurrence rate. Patient survival rate was 85% at 10 years and 76% at 20 years. Renal survival rate was 96% at 10 years and 86% at 20 years, 100% at 10 years and 80% at 20 years in ClassIV-G. In the multivariate Cox hazard analysis of the clinicopathologic factors, serum creatinine was selected as the most significant risk factor for death and/or end-stage renal failure (p=0.036). In addition, the chronicity index was also a significant risk factor for renal survival of LGN. CONCLUSION: This retrospective analysis of LGN showed better outcomes than expected. Overall, early diagnosis and suitable initial therapy may improve the renal survival of LGN in both groups of patients.