Two novel APOA1 gene mutations in a Japanese renal transplant recipient with recurrent apolipoprotein A-I related amyloidosis.

Apolipoprotein A-I amyloidosis is a rare, autosomal dominant disorder of APOA-1 gene characterized by the deposition of apolipoprotein A-I in various organs and can be classified into either hereditary or nonhereditary form in the absence of a family history. Renal disease caused by Apolipoprotein A-I amyloidosis commonly manifested as slowly progressive renal function impairment without heavy proteinuria. Apolipoprotein A-I-related amyloidosis of kidney is of pathogenetic interest because the renal failure is due to peritubular and interstitial amyloid deposits without glomerular deposits. Tubulointerstitial lesion of amyloid deposits was diagnosed in half of carriers of APOA1 gene mutation, only 13% of patients progressed to renal failure requiring hemodialysis or kidney transplantation. Recurrence of apolipoprotein A-I-related amyloidosis after kidney transplantation is very rare. We report a case of a 63-year-old Japanese female without a family history of kidney and/or liver disease who showed slowly progressive renal graft dysfunction without overt proteinuria. Graft biopsy revealed characteristic Congo red stain positive amyloid deposits localized in the renal interstitial area. No glomerular, vascular and tubular amyloid deposits were noted. Laser microdissection-liquid chromatography tandem mass spectrometry-based proteomic analysis elucidated the type of amyloidosis as apolipoprotein A-I amyloidosis. Genetic analysis of DNA sequence study revealed two novel APOA1 gene mutations of Leu202Arg and Lys262Asn. This is a first and very rare case report of the recurrence of non-familial hereditary apolipoprotein A-I amyloidosis in Japanese transplant recipient.

Reviewing the pathogenesis of antibody-mediated rejection and renal graft pathology after kidney transplantation.

The clinicopathological context of rejection after kidney transplantation was well recognized. Banff conferences greatly contributed to elucidate the pathogenesis and to establish the pathologic criteria of rejection after kidney transplantation. The most important current problem of renal transplantation is de novo donor-specific antibody (DSA) production leading chronic rejection and graft loss. Microvascular inflammation is considered as a reliable pathological marker for antibody-mediated rejection (AMR) in the presence of DSA. Electron microscopic study allowed us to evaluate early changes in peritubular capillaries in T-lymphocyte mediated rejection and transition to antibody-mediated rejection. Severe endothelial injuries with edema and activated lymphocyte invaded into subendothelial space with early multi-layering of peritubular capillary basement membrane suggest T-lymphocyte mediated rejection induce an unbounded chain of antibody-mediated rejection. The risk factors of AMR after ABO-incompatible kidney transplantation are important issues. Anti-ABO blood type antibody titre of IgG excess 32-fold before transplant operation is the only predictable factor for acute AMR. Characteristics of chronic active antibody-mediated rejection (CAAMR) are one of the most important problems. Light microscopic findings and C4d stain of peritubular capillary and glomerular capillary are useful diagnostic criteria of CAAMR. Microvascular inflammation, double contour of glomerular capillary and thickening of peritubular capillary basement are good predictive factors of the presence of de novo DSA. C4d stain of linear glomerular capillary is a more sensitive marker for CAAMR than positive C4d of peritubular capillary. Early and sensitive diagnostic attempts of diagnosing CAAMR are pivotal to prevent chronic graft failure.

Ability of vitamin D receptor activator to prevent pulmonary congestion in advanced chronic kidney disease.

BACKGROUND: Vitamin D deficiency is common among patients with chronic kidney disease (CKD). However, the benefits of vitamin D supplementation versus vitamin D receptor activator (VDRA) administration have yet to be established. Recently, an association between activated vitamin D and cardiovascular factors was reported. To evaluate the benefits of VDRA in advanced CKD, we analyzed the association between VDRA administration and the prevalence of pulmonary congestion. METHODS: This retrospective, cross-sectional analysis included patients initiated on dialysis between October 2011 and September 2013 at 17 Japanese institutions. Data from 952 participants were analyzed using a multivariate logistic regression model and a linear regression model. We also analyzed subgroup data for groups classified by selection of peritoneal dialysis or hemodialysis. RESULTS: Of the 952 participants, 303 patients received VDRA. VDRA administration was associated with a low prevalence of pulmonary congestion in the multivariate logistic regression model (odds ratio [OR], 0.64; 95 % confidence interval [CI], 0.44-0.94; P = 0.02). There was no significant association between VDRA administration and systolic blood pressure, diastolic blood pressure, or pulse pressure. Subgroup analysis revealed a tendency that VDRA administration was associated with low prevalence of pulmonary congestion in both groups. CONCLUSIONS: In this study, VDRA administration was associated with a low prevalence of pulmonary congestion in patients initiated on dialysis. Appropriate VDRA administration may prevent pulmonary congestion.

Recurrent glomerular disease after kidney transplantation: an update of selected areas and the impact of protocol biopsy.

Recurrence of native kidney disease following kidney transplantation affects between 10% and 20% of patients, and accounts for up to 8% of graft failures. In a considerable number of recipients with transplant glomerulopathy, it is impossible to distinguish between recurrent and de novo types. An accurate estimate of the incidence of recurrence is difficult due to limitations in the diagnosis of recurrent glomerulonephritis. De novo glomerular lesions may be misclassified if histological confirmation of the patient's native kidney disease is lacking. Asymptomatic histological recurrence in renal allografts may be missed if protocol biopsies are not available. Studies based on protocol biopsy are pivotal to accurately estimate the incidence of recurrence. Many factors are known to influence recurrence of kidney disease after transplantation, including the type and severity of the original disease, age at onset, interval from onset to end-stage renal disease, and clinical course of the previous transplantation. Early recognition of recurrence is possible in several glomerular diseases. Factors such as the existence of circulating permeability factors, circulating urokinase receptor and anti-phospholipase A2 receptor antibody, as well as disorders of complement regulatory proteins like factor I mutation and factor H mutation factors are expected to be useful predictors of recurrence. Peculiar clinical course of atypical haemolytic uremic syndrome after kidney transplantation is an informative sign of recurrent glomerular disease. These factors play pivotal roles in the development of recurrence of certain types of glomerulopathies. Understanding the pathogenesis of recurrent glomerulonephritis is critical to optimize prevention as well as treat individual cases of recurrent glomerulonephritis. Subclinical recurrence of IgA nephropathy after kidney transplantation is well recognized. Only protocol biopsies of clinically silent recipient can provide the accurate prevalence of recurrent IgA nephropathy. The study of recurrent glomerulonephritis will contribute not only to improving long-term graft survival, but also to clarifying the pathogenesis of glomerulonephritis. Protocol biopsy is one the most effective methods for elucidating the pathogenesis of recurrent glomerulonephritis.

Early recurrence of active IgA nephropathy after kidney transplantation.

IgA nephropathy (IgAN) is recurrent after transplantation; however, its time of recurrence is unpredictable. To date, factors influencing IgAN recurrence have not been elucidated. We present a case of a 23-year-old man with end-stage renal disease (ESRD) who underwent living-related ABO-identical pre-emptive kidney transplantation (PEKT) using his 57-year-old mother as a donor. IgAN started when the patient was 19 years old, and renal biopsy revealed the usual pathological findings of IgAN. In spite of steroid therapy including steroid pulse and tonsillectomy, the patient developed nephrotic syndrome and progressed to ESRD in 4 years. Protocol biopsy on day 19 following PEKT revealed active recurrent IgAN. Nephrotic-range proteinuria and mild deterioration of kidney function developed regardless of strong immunosuppressive therapy such as steroid pulse, double filtration plasmapheresis and rituximab. We report a case of refractory IgAN that recurred 19 days after transplantation. This case is considered of value to elucidate factors leading to active IgAN recurrence.

Decreased glomerular filtration as the primary factor of elevated circulating suPAR levels in focal segmental glomerulosclerosis.

BACKGROUND: Circulating factor(s) has been thought to be the underlying cause of focal segmental glomerulosclerosis (FSGS), and recent studies foster this idea by demonstrating increased soluble urokinase receptor (suPAR) levels in the serum of FSGS patients. METHODS: To explore the possible contribution of suPAR in FSGS pathogenesis, we analyzed serum suPAR levels in 17 patients with FSGS and compared them with those in patients with steroid-sensitive nephrotic syndrome, chronic glomerulonephritis, or non-glomerular kidney diseases. RESULTS: Serum suPAR levels in patients with FSGS were higher than those in patients with steroid-sensitive nephrotic syndrome or chronic glomerulonephritis, but not higher than those in patients with non-glomerular kidney diseases. suPAR levels negatively correlate with estimated glomerular filtration rate and were decreased after renal transplantation in patients with FSGS as well as in those with non-glomerular kidney diseases. Furthermore, 6 FSGS patients with post-transplant recurrence demonstrated that suPAR levels were not high during the recurrence. CONCLUSIONS: Based on our results, elevated suPAR levels in FSGS patients were attributed mainly to decreased glomerular filtration. These data warrant further analysis for involvement of possible circulating factor(s) in FSGS pathogenesis.

Significance of C4d deposition in antibody-mediated rejection.

The C4d staining as a special tissue marker for humoral immunity has served criteria of pathological diagnosis for antibody-mediated rejection (ABMR) in Banff classification since 2003. However, the sensitivity and specificity of C4d staining have been questioned, and recently, C4d-negative ABMR has been more focused in renal allograft pathology. The aim of this study was to make certain of C4d staining for ABMR that was diagnosed by clinical and morphological findings. C4d staining was employed by immunofluorescence. This study included 14 patients with acute ABMR and 16 with chronic active ABMR. Eight of acute ABMR were ABO-blood-type-incompatible renal transplantation (ABOinRTx) pre-treated by DFPP and splenectomy or rituximub. In acute ABMR after ABOinRTx, C4d staining along peritubular capillary (PTC) was positive in five of them (62.5%). Only one graft biopsy of five acute ABMR with donor-specific antibody (DSA) showed C4d positive. We assembled 16 graft biopsies showing typical transplant glomerulopathy and thickened PTC basement membrane with peritubular capillaritis as a suspicious pathological chronic active ABMR. Four of eight DSA-positive patients were C4d negative in PTC; however, three of four DSA-positive and C4d-negative patients in PTC chronic active ABMR were C4d positive in only glomerular capillaries. C4d positivity could not come to a specific marker of ABMR diagnosing based on clinically and ordinary morphological findings.

A recurrent fibronectin glomerulopathy in a renal transplant patient: a case report.

Fibronectin glomerulopathy (FNG) is a rare, autosomal dominant renal disease with massive mesangial, and subendothelial fibronectin deposits. It presents proteinuria, often in the nephrotic range in the third to fourth decade, and slow progression to end-stage renal disease. The risk of recurrent disease in renal allograft is uncertain. A Japanese female with end-stage renal disease because of unknown origin received a renal transplant and was referred with proteinuria and mild deterioration of renal function four months after transplantation. Five allograft biopsies were underwent from one h to 12 months after the transplantation, including a biopsy 19 d after the transplantation, which revealed dense deposits suggesting fibronectin. A biopsy 134 d after the transplantation showed a feature of lobular glomerulonephritis corresponding FNG. The diagnosis was confirmed by IST4 positive and IST9 negative immunostaining together with typical fibrillary dense deposits in the mesangium and subendothelial spaces in electron microscopy. This is the first report of recurrent FNG in Japan.

A case of recurrent light chain deposition disease after living-related renal transplantation - detailed process of the recurrence.

A 53-yr-old woman with end-stage renal disease was admitted for renal transplantation (RTX). About a decade ago, she had presented with urinary abnormalities. Monoclonal IgA lambda was detected. Renal biopsy showed nodular glomerulosclerosis, and an immunohistochemical study for lambda was negative. Fibrillary glomerulonephritis was suggested as the most likely diagnosis. RTX was successfully performed, and graft function was stable for the first half year. Graft biopsy was performed at one yr post-transplant. Glomeruli showed nodular lesion similar to native kidney biopsy findings. Immunofluorescence microscopy (IF) indicated strong lambda staining along the glomerular basement membrane, the tubular basement membrane (TBM), and the peritubular capillary. The diagnosis of recurrent light chain deposition disease (LCDD) was confirmed. A series of biopsies are available to conduct studies on the recurrent process of LCDD. Light microscopy showed no remarkable changes up to six months post-RTX. However, the IF study revealed evident granular depositions of lambda along the TBM only at the one-h biopsy. Typical IF staining pattern of lambda and EDD compatible with LCDD were noted after six months post-transplant. This is the first case report that elucidated the details of the recurrent process of LCDD at one yr after the operation.

Peculiar renal endarteritis in a patient with acute endocapillary proliferative glomerulonephritis.

Acute glomerulonephritis (AGN) is one of the most common renal diseases. They are often associated with infections and can result in diffuse proliferative glomerulonephritis (GN). This case report reviews an interesting case in which renal endarteritis coexisted in AGN with diffuse endocapillary proliferation. The discussion highlights important pathological findings and clinical aspects in acute endocapillary proliferative GN with renal endarteritis. Coexisting endarteritis should be in the differential diagnosis of AGN in patients with persistent clinical courses.

Current problems of chronic active antibody-mediated rejection.

The Banff 2007 classification allows chronic rejection to be differentiated based on clinicopathological characteristics evidenced by two independent immunologic mechanisms; chronic active antibody-mediated rejection and chronic active T-lymphocyte mediated rejection. However, several incompletely understood issues concerning chronic active antibody-mediated rejection remain. Chronic active antibody-mediated rejection is characterized by C4d deposition in the capillary basement membrane(PTC), the presence of circulating anti-donor antibodies(DSA), and morphologic evidence of chronic tissue injury such as glomerular double contours compatible with transplant glomerulopathy (TPG), PTC basement membrane multilayering, interstitial fibrosis/tubular atrophy, and fibrous arterial intimal thickening. PTC basement membrane multilayering correlates highly with TPG, and most of TPG have evidence of either C4d-positive staining or DSA. However, the proposed criteria do not apply to all situations of chronic active antibody-mediated rejection. C4d is not a magic marker for antibody-mediated rejection. C4d staining is not always highly sensitive for detecting antibody-mediated rejection. Multi-institutional studies should be conducted to better understand the clinicopathological context of chronic antibody-mediated rejection. These studies should include well-designed serial protocol biopsies with evaluation by electron microscopy, C4d staining performed on frozen sections, and assessment using sensitive DSA detection methods.

Is arteriolar vacuolization a predictor of calcineurin inhibitor nephrotoxicity?

Calcineurin inhibitors (CNI) have been commonly used as pivotal immunosuppressive agents to renal transplant recipients and have contributed significantly to improving short-term allograft survival. However, long-term administration of CNI may cause an adverse effect on kidney function, known as chronic nephrotoxicity. Chronic CNI nephrotoxicity (CNI-NT) shows characteristic histopathological findings that involve arteriolar hyalinosis. Recently, the term alternative arteriolar hyalinosis (aah) is used to discriminate CNI-specific arteriolar hyaline deposition from non-specific arteriolar hyalinosis. We studied whether arteriolar vacuolization represents an early lesion of aah as a predictor of CNI-NT. We retrospectively studied the 79 patients under treatment with a CNI immunosuppressant, who underwent living-related renal transplantation (RTx) from January 2007 to March 2009. We examined serial protocol graft biopsies at one h, one, six, and 12 months after RTx. We classified histological findings into two groups on the basis of aah lesion (with or without aah) in serial biopsies for 12 months. Arteriolar vacuolization was more frequently observed in the aah group than in the non-aah group with a significant difference. Arteriolar vacuolization was found even in the one-h biopsy specimens, indicating a non-specific histopathological finding. But in the aah group, arteriolar vacuolization tended to be more frequently observed later on. Aah can be a predictor of CNI-NT.

A case report of recurrence of mixed cryoglobulinemic glomerulonephritis in a renal transplant recipient.

Recurrence of glomerulonephritis (GN) is one of the major risk factors of long-surviving renal graft dysfunction. Cryoglobulinemic glomerulonephritis of hepatitis-C virus (HCV)-negative patient is a rare cause of end-stage renal disease. There is little case report of recurrent cryoglobulinemic glomerulonephritis in negative HCV recipients after renal transplantation. We represent a renal allograft recipient of an interesting recurrent cryoglobulinemic glomerulonephritis. The patient was diagnosed with mixed cryoglobulinemic glomerulonephritis by kidney biopsy at the age of 32 . He had no HCV, HBV nor liver dysfunction. He received immunosuppressive therapy, however, was introduced to hemodialysis treatment after 13 yr. He received a cadaveric renal transplantation at the age of 50, and immunosuppressive treatment was started with ciclosporin, prednisolone and mycophenolate mofetil (MMF). Four yr after transplantation, he developed fever and purpura of lower limbs. His serum creatinine level did not increase, however, proteinuria, hematuria, hypocomplementemia, positive rheumatoid factor and mixed cryoglobulinemia were noted. Detailed analysis failed to reveal the composition of mixed cryoglobulinemia. The renal allograft biopsy showed membranoproliferative-type GN with monocyte and polynuclear leukocyte accumulation of capillary loops and small cellular crescent. Immunofluorescent study showed C3, IgG and IgM deposition of mesangial and capillary pattern. Regardless of steroid pulse therapy, hypocomplementemia and positive rheumatoid factor did not improve. Ten yr after transplantation, he was affected by cellulitis and sepsis. Afterward, rising of serum creatinine and nephrotic range proteinuria developed. The allograft biopsy revealed advanced cryoglobulinemic glomerulonephritis with characteristic vascular lesions. Electron microscopy showed organized subendothelial deposits compatible with cryoglobulinemic glomerulonephritis and proteinaceous thrombus in arteriole.

A case of acute rejection with adenovirus infection after ABO-incompatible kidney transplantation.

We report clinical and histopathologic findings of a case of acute rejection with adenovirus infection after kidney transplantation. A 63-yr-old woman with end-stage renal disease caused by lupus nephritis received an ABO-incompatible living kidney transplantation from her husband. On the 7th post-operative day (POD), she had fever, hematuria, and bladder irritation. Although she was treated with an antibiotic, the symptoms were not improved. We diagnosed adenovirus infection as positive with the urine shell vial method and blood PCR analysis. Cyclophosphamide was interrupted and immunoglobulin therapy was performed. However, urine output decreased and serum creatinine levels increased. An episode biopsy was performed on POD 20. We diagnosed acute antibody-mediated rejection. She was treated with plasma exchange for acute rejection and antiviral drug (rivabirin) for active adenovirus infection. However, the renal graft dysfunction was deemed irreversible and the renal graft was removed on POD 34. The graftectomy specimen showed acute rejection and acute tubular necrosis with adenovirus infection.

Benefits of cyclosporine absorption profiling in nephrotic syndrome: preprandial once-daily administration of cyclosporine microemulsion improves slow absorption and can standardize the absorption profile.

AIM: Cyclosporine is known to improve proteinuria in nephrotic syndrome (NS), but is also associated with drug-related renal impairment. In this case series, therapeutic drug monitoring using the absorption profile was applied to adults with NS to investigate the efficacy and safety of once-daily administration of cyclosporine microemulsion (CSAME). METHODS: Twenty patients received CSAME starting at 100-175 mg/day (1.4-3.1 mg/kg per day) once daily after breakfast. The area under the concentration-time curve up to 4 h after administration of cyclosporine (AUC(0-4 h)) was determined in each patient within 1 week after the start of CSAME treatment. Thereafter, the dose of CSAME was adjusted according to the absorption profile. RESULTS: After 6 months, treatment with CSAME improved efficacy test values compared with those prior to treatment, and the severe nephrotic state was eliminated in all patients. No changes in serum creatinine or blood urea nitrogen levels were observed. The dose of CSAME was adjusted so that AUC(0-4 h) and the peak level fell within the range of target values, resulting in a significant decrease in the mean dose of cyclosporine (P = 0.0001). Time of peak level was variable among patients, but when CSAME was administered before breakfast, good absorption was achieved in all patients. CONCLUSION: By monitoring the absorption profile in patients with NS, a once-daily administration of CSAME was used to achieve both efficacy and a reduction in total exposure to the drug. Preprandial administration provided a more stable absorption profile of cyclosporine. The authors hope this method will become standard procedure during cyclosporine treatment in these patients.

Oral carbonaceous absorbent modifies renal function of renal ablation model without affecting plasma renin-angiotensin system or protein intake.

BACKGROUND: Although it has been repeatedly shown that the oral carbonaceous absorbent AST-120 ameliorates the progression of chronic renal failure, the mechanisms remain unknown. METHODS: Male Sprague-Dawley rats (6 weeks old), weighing 180-210 g, were 4/5 nephrectomized, and were divided into two groups: one given AST-120 (0.4 g/100 g body weight BW; n= 9) and the other not given AST-120 ( n = 9). Body weight, blood pressure, and serum and urine chemistry, as well as the plasma components of the renin-angiotensin system, were measured for 22 weeks. RESULTS: Proteinuria was significantly greater in the controls than in the AST-120 group (102 +/- 22 vs 51 +/- 7 mg/day at 22 weeks). Urea clearance was lower in the former (3.7 +/- 0.4 vs 3.9 +/- 0.4 ml/min). There were no differences in plasma renin activity (1.4 +/- 0.3 vs 1.9 +/- 0.4 mg/ml per h), or in angiotensin I (756 +/- 119 vs 1042 +/- 168 pg/ml) and II (35.1 +/- 7.4 vs 46.6 +/- 7.6 pg/ml) or angiotensin-converting enzyme activity (39.0 +/- 2.4 vs 37.9 +/- 2.2 IU/l) between the two groups. Protein intake, estimated from urinary urea appearance, was not different. Serum phosphate concentration (6.6 +/- 0.3 vs 5.9 +/- 0.3 mg/dl) was higher in the control than in AST-120, while the urinary phosphate excretion rate (31.5 +/- 0.8 vs 28.1 +/- 1.8 mg/day) tended to be lower in the latter. Conclusions. AST-120 retarded the progression of renal failure in the 4/5 renal ablation model without affecting the plasma renin-angiotensin system or protein intake, both of which were the most important risk factors for the progression of renal failure. We hypothesize that the renal protective effects of the oral absorbent AST-120 may be, at least in part, due to its lowering phosphate absorption from the diet as a phosphorus binder.

A case report of a renal transplant recipient developing chronic glomerular rejection with a weak antibody against anti-donor T-cell, only detected by flow-cytometry crossmatch.

The pathogenesis of antibody-mediated rejection has been investigated, but the precise mechanism of chronic glomerular rejection remains unclear. We have followed the clinicopathological course of a patient with pre-existing anti-donor antibody only detected by flow-cytometry crossmatch for over 3 years. Glomerular endothelial injuries and peculiar glomerular lesions were noted in biopsy specimen of postoperative year 3; however, both typical chronic vascular rejection lesions and peritubular capillary multilayered lesions were not revealed. We consider that the presence of weak anti-donor antibody leading early onset of acute humoral rejection played a role in the pathogenesis of early onset of chronic transplant glomerulopathy.

Complement fragment C4d deposition in peritubular capillaries in acute humoral rejection after ABO blood group-incompatible human kidney transplantation.

BACKGROUND: Acute humoral rejection (AHR) is the most important risk factor for early graft loss in ABO-incompatible (ABO-i) kidney transplantation (RTx). The pathogenesis and diagnostic criteria for AHR after ABO-i RTx remain unclear. Complement fragment C4d deposition in peritubular capillaries (PTC), which is a sensitive indicator for activation of the classical complement pathway, was studied to establish the pathologic diagnostic indicator of AHR. METHODS: Forty-four graft biopsy specimens from 19 patients with ABO-i living donors were analyzed within 90 days after RTx. Nineteen biopsy specimens with acute rejection after ABO-compatible (ABO-c) living-related RTx were used as controls. Diffuse and bright C4d deposition in PTC was considered significantly positive. RESULTS: All of 8 recipients with AHR showed significantly positive C4d in PTC in the ABO-i group, but 9 of 11 recipients without AHR were negative. In the ABO-c RTx group, 16 of 19 recipients were negative for C4d in PTC. The prevalence of C4d in PTC was significantly higher in ABO-i RTx (P<0.05). CONCLUSIONS: C4d deposition is valuable as a specific and sensitive indicator for AHR, even of mild severity, in ABO-i RTx.