Experiences of high-dose mizoribine as antimetabolite immunosuppressants for kidney transplantation.

We have used low doses of mizoribine (MZ) or mycophenolate mofetil (MMF) as induction and maintenance immunosuppressants, but since 2009 have employed a high dose of MZ. We reviewed the efficacy and side effects of MZ compared with MMF. It is difficult to compare graft survivals between these periods because of different patient demographics, though the high dose of MZ cohort showed no significant difference from MMF. High doses of MZ serum to prevent acute rejection episodes as the induction and maintenance therapy. MZ controlled with blood concentrations showed less side effects, suggesting that high MZ doses could be safely used for an induction and maintenance antimetabolite.

Disseminated strongyloidiasis in nephrotic syndrome.

Strongyloides stercoralis is endemic in the southwestern islands Amami and Ryukyu in Japan. Systemic strongyloidiasis occurs in immunocompromised hosts. We report here on a 60-year-old patient with minimal-change nephrotic syndrome (MCNS) without eosinophilia or HTLV-I infection. She was treated with corticosteroid for MCNS and died of disseminated strongyloidiasis. The patient developed systemic purpura, ileus, respiratory distress, malabsorption, pancytopenia, pulmonary hemorrhage and sepsis due to Escherichia coli before death. Massive infestation with Strongyloides stercoralis was disclosed by autopsy, and the larvae was considered as a pathomechanism or exacerbating agent of nephrotic syndrome in endemic areas.

Obesity associated with hypertension or hyperlipidemia accelerates renal damage.

Obesity is known as a risk factor for nephropathy, especially nephrotic syndrome and focal segmental glomerulosclerosis, and can aggravate renal dysfunction. However, whether these changes are caused by obesity itself or by the associated hypertension (HT) and hyperlipidemia (HC) remains unclear at present. We investigated the influence of HT and HC in obesity on glomerular morphometry. The study included cases with obesity alone (O, body mass index more than 25 kg/m(2), n = 16), O+HC (n = 8), O+HT (n = 17), HC (n = 10) alone, HT (n = 7) alone, and normal subjects (N, n = 11). Renal biopsies were examined and the glomerular diameter, and length and diameter of the glomerular capillary loop were determined using image analysis software. Clinically related data were obtained from medical records at the time of biopsy. Obesity was associated with dilatation of glomerular diameter due to glomerular loop elongation. However, end-stage renal disease (ESRD) was not noted in patients with obesity only. In contrast, ESRD requiring hemodialysis was noted in group O+HT within a 7.7-year follow-up period. Furthermore, enlargement of loop diameter was noted in group O+HC, but not in HC alone. These results suggest that obesity alone may not result in glomerular hyperfiltration or renal dysfunction, but obesity associated with hypertension or hyperlipidemia may accelerate renal damage.

Benign nephrosclerosis: incidence, morphology and prognosis.

AIMS: Study of benign nephrosclerosis (BNS) is often mixed up with IgA nephritis (IgAN) associated with hypertension or thin basement membrane disease (TBMD). Here we examined the clinicopathological features, incidences and prognosis of decompensated BNS. MATERIALS AND METHODS: BNS was identified in 590 (8.3%) adult cases among 7,108 renal biopsies of a mean age of 56.5 years (male: female ratio = 2.5:1). The post-biopsy follow-up period ranged from 3 to 22 years (10.1 +/- 4.6 years). RESULTS: Patients with progressive BNS were more likely to develop end-stage renal disease within 5 years of biopsy. Poor prognostic factors included poor or no control of arterial blood pressure by anti-hypertensive drugs, global glomerulosclerosis (GS) (> or = 41%) at biopsy, presence of collapsed glomeruli and/or segmented or semi-global GS. Tubulointerstitial damage, glomerular hypertrophy and loop dilatation were secondary to GS. Gender, duration of HT and onset of HT to biopsy were not significant factors. CONCLUSION: GS in BNS is due to ischemia induced by luminal narrowing or obstruction of preglomerular vessels, and glomerular HT due to loss of autoregulation in preglomerular vessels (irregularly shaped atrophic or segmented medial smooth muscle cells, with expansion of extracellular matrix with or without fibrous intimal thickening). GS resulted in luminal dilatation. Both pathological changes affecting the glomerulus may occur in the same kidney and different nephron units.

Histopathological evidence of poor prognosis in patients with vesicoureteral reflux.

Patients with vesicoureteral reflux (VUR) often develop reflux nephropathy with focal segmental glomerular sclerosis (FSGS), although the exact mechanisms leading to the development of this complication are unknown. To determine the early changes in glomeruli of VUR patients that ultimately cause poor renal outcome, we examined morphometrically renal biopsies of 16 young patients (age 10-20 years) with VUR at baseline pre-operatively. Patients were divided into two groups, those who subsequently showed good prognosis and those with poor renal prognosis at the end of a 10-year follow-up period. Patients with poor prognosis had worse proteinuria and lower creatinine at baseline than those with good prognosis. We also examined 40 age-matched control cases with previous temporal microhematuria and/or proteinuria but normal renal function and histology. Although the mean diameter of glomerular capillary did not change in VUR cases irrespective of prognosis, glomerular capillary length increased by 125% in cases with good prognosis, and 335% in cases with poor prognosis (P < 0.01). Cystically expanded capillaries, with diameter > or = 95% of that in age-matched control, were detected in five of eight patients with poor prognosis, but only in one of eight patients with good prognosis. In VUR, the number of podocytes/capillary diminished with increased length of the capillaries. Tuft adhesion to Bowman's capsule and podocyte detachment were primarily found in patients with poor prognosis. Our results suggest that lengthening of glomerular capillaries in young patients with VUR is a compensatory reaction to hyperfiltration. The appearance of cystic capillary expansion, podocyte detachment and/or tuft adhesion to Bowman's capsule in such glomeruli may be important indicators of renal prognosis in patients with VUR. These changes may lead to FSGS due to podocyte injury in patients with VUR, with subsequent deterioration of renal function.

Macrophage subclasses and proliferation in childhood IgA glomerulonephritis.

We immunohistologically compared the number of intraglomerular infiltrating cells in 14 children with poststreptococcal acute glomerulonephritis (PSAGN) and 20 children with immunoglobulin A glomerulonephritis (IgAGN) with histological characteristics similar to those of PSAGN to explain the difference in clinicopathological characteristics between these two diseases. Immunohistological study was performed in kidney tissues from these patients by using monoclonal antibodies of T-cell marker (CD3 and CD45RO), B-cell marker (CD20), neutrophil marker (CD15), macrophage marker (CD68), four subclasses of macrophages (early-stage, acute-stage, chronic-stage, and mature inflammatory macrophage marker), and proliferating cell nuclear antigen (PCNA). The 34 patients were classified into three stages according to the time from the detection of urinary abnormalities to biopsy. Intraglomerular immunopositive cells were expressed as the number of cells per glomerulus. There were more intraglomerular positive cells of CD15, CD68, and the four macrophage subclasses in PSAGN than IgAGN. The number of intraglomerular infiltrating macrophages decreased with time in PSAGN, whereas the number of macrophages in IgAGN remained constant at all stages. Intraglomerular infiltration of acute-stage inflammatory macrophages alone was evident in IgAGN. Both the number of intraglomerular proliferating macrophages (PCNA-positive plus CD68-positive cells) and proportion of proliferating macrophages/total macrophages were greater in IgAGN than PSAGN. Normal urinalysis results were evident in all patients with PSAGN during follow-up, and urinary abnormalities persisted in 18 patients with IgAGN. In conclusion, differences in the maturity of infiltrating macrophages and number of proliferating macrophages are associated with the different clinicopathological characteristics in children with PSAGN and IgAGN.

Prognosis of renal amyloidosis: a clinicopathological study using cluster analysis.

Progression of renal amyloidosis is associated with severe proteinuria or nephrotic syndrome, and various mechanisms have been postulated to explain these complications. We studied the acceleration of proteinuria and reduced renal function by cluster analysis using clinical parameters, renal histological findings, type of renal amyloidosis and follow-up data. We divided 97 cases into three groups of renal amyloidosis. Accelerated progression correlated with serum creatinine (s-Cr) levels at renal biopsy and histological grade of renal damage by amyloid deposition (p < 0.0001). The most influential prognostic factors (s-Cr level > or =2.0 mg/dl) were tubulointerstitial and vascular damage induced by amyloid deposition at biopsy (odds ratio 96.9 and 69.2, respectively). In addition, we found amyloidosis type amyloid associated (AA) correlated with more amyloid-mediated vascular and tubulointerstitial damage than amyloidosis type amyloid light chain (AL) (p < 0.001, p < 0.01, respectively). Proteinuria and nephrotic syndrome were more severe in cases of amyloidosis AL than in amyloidosis AA (p = 0.076). In conclusion, less tubulointerstitial and vascular damage was caused by amyloid deposition; this was slowly progressive. Amyloid AA was detected in tubulointerstitial tissue and vessels more frequently than amyloid AL. Heavy proteinuria and/or nephrosis were not indicators of rapid progression.

Causal relationship between conformational change and inhibition of domain functions of glycoxidative fibronectin.

Glycoxidative modification of various body proteins, including fibronectin (FN), has been shown to change their structural and functional properties, and be implicated in pathogenesis of diabetic complications. Little is known about the role of secondary structure of glycoxidative FN (gFN) in its domain functions. gFN was prepared by incubation with 25 and 200 mM glucose in 0.2 M sodium phosphate buffer at 37 degrees C on a shaking plate under aerobic and sterile conditions for various time intervals up to 49 days, being defined as gFN25 and gFN200, respectively. Unmodified FN (uFN) was prepared by incubation in 0.2 M sodium phosphate buffer without any glucose at 4 degrees C for 49 days. The extent of glycoxidative modification was examined using a noncompetitive enzyme-linked immunosorbent assay with an antibody against N(epsilon) -(carboxymethyl)lysine (CML), one of the major glycoxidation products. The binding activities of uFN and gFN to collagen, gelatin and heparin were determined by a solid phase enzyme immunoassay or heparin-affinity HPLC. Cell attachment was estimated by the extent of adhesion of FITC-labeled smooth muscle cells to uFN or gFN. Conformational change in gFN was detected by SDS-polyacrylamide gel electrophoresis and spectroscopy (circular dichroism). CML was detected in gFN25 and gFN200 after 49 and 21 days of incubation, respectively. Levels of CML were about six-fold higher in gFN200 than in gFN25 after 49 days. Both gFN25 and gFN200 showed a significant decrease in the ability of binding to collagen and gelatin after 7 days of incubation. The binding activity for heparin was significantly decreased in both gFN25 and gFN200 after one day. Cell attachment activity was reduced to 89% and 76% of the unmodified form in both gFN25 and gFN200 after 49 days, respectively. High molecular weight materials were found in gFN25 and gFN200 after 21 and 7 days, respectively. CD spectrum showed that gFN25 had lost its native conformation after 3 days of incubation, depending upon the concentration and incubation interval of the applied glucose. These in vitro results suggest that the loss of native conformation may reduce the domain functions of gFN, including binding activity to macromolecular ligands and cell attachment, and may play a major role in the pathogenesis of diabetic complications.

Patients with renal hypouricemia with exercise-induced acute renal failure and chronic renal dysfunction.

We here report the case of a 38-year-old male with back pain and vomiting occurring after exercise. Serum creatinine level was elevated, and he was admitted to our hospital with diagnosis of acute renal failure (ARF). He had experienced similar attacks at least 4 times, including the present episode, from the age of 22 years. After admission, the patient was managed only by resting, and remission was nearly attained in about 1 month. The renal biopsy specimen performed on day 15 showed findings of acute tubular necrosis, thickening of the tubular basement membrane, and interstitial fibrosis. After remission, the serum uric acid level was 0.7-0.8 mg/dl, fractional excretion of uric acid was 0.63, and the possibility of other diseases facilitating the excretion of uric acid was denied. Therefore, ARF associated with idiopathic renal hypouricemia was diagnosed. Since only mild responses were observed in a pyradinamide loading test and a benzbromarone loading test, the case was considered to be a presecretary reabsorption disorder type. Renal function tests showed the almost complete recovery of the glomerular filtration rate (GFR: 114 ml/min/1.73 m2), but the urine concentrating ability was markedly decreased (specific gravity 1.019 and osmolarity 516 mOsm/kgxH2O in Fishberg test). Past data from this patient indicated that this renal dysfunction had been persisting for ten years. We examined 9 patients with renal hypouricemia and focused on the differences between the two groups (with or without complications). Four patients had a history of exercise-induced ARF or calculus. The urine concentrating ability was significantly lower in these patients (group A) than in the other patients without complications (group B). The glomerular filtration rate in group A was within the normal range, but was lower than in group B. These results suggested the possibility that patients with renal hypouricemia with complications may have chronic renal dysfunction in the future.

Possible involvement of altered RGD sequence in reduced adhesive and spreading activities of advanced glycation end product-modified fibronectin to vascular smooth muscle cells.

Although fibronectin (FN) modified by advanced glycation end products (AGEs) has been shown to contribute to the development of diabetic vascular complications through its reduced adhesive activity to vascular cells, little is known about changes in the cell binding domain of AGE-modified FN. Here we examined the mechanism of reduced adhesive and spreading activities of AGE-modified FN to vascular smooth muscle cells (SMCs), particularly the contribution of modification of Arg-Gly-Asp (RGD) sequence. Incubation with glucose caused not only the formation of N(epsilon) -carboxymethyllysine and pentosidine, but also polymerization of FN in a dose- and time-dependent manner. AGE-modified FN had significantly low adhesive and spreading activities to cultured SMCs. On the other hand, multimeric FN formed by disulfide bonds did not show any effect on either cell adhesion or spreading. The adhesive activity of type I collagen, one of the RGD sequence-containing proteins, to SMCs also decreased by AGE-modification. The inhibitory effect of AGE-modification on cell adhesion was significantly greater in type I collagen than in FN. Although the extent of AGE-modification of type I collagen was indistinguishable from that of FN, AGE-modification decreased the arginine content of type I collagen by 69.5% and of FN by 30.6%, compared with their non-glycated forms. The addition of RGD peptides caused a decrease in adhesion of SMCs to non-glycated FN, but not to AGE-modified FN. Modification of RGD sequence with glyoxal eliminated its inhibitory effect on cell adhesion. Our results suggest that a marked decrease in adhesive and spreading activities of AGE-modified FN to SMCs might largely be due to a modification of its RGD sequence by AGE, thus suggesting a potential link between AGE modification of FN and the pathogenesis of diabetic angiopathy.

A clinical and pathological study on the characteristics and factors influencing the prognosis of crescentic glomerulonephritis using a cluster analysis.

Crescentic glomerulonephritis (CrGN) is expressed by a rapidly progressive lesion. However, there is no unanimous view on the factors that affect the prognosis. We carried out a follow-up study of 109 CrGN patients consisting of 54 males (age 55.3 +/- 15.7) and 55 females (age 54.0 +/- 16.3) by a cluster analysis using pathomorphological parameters at the time of biopsy, and thus found two categories which were significantly different regarding the speed of progress (P = 0.0249). The component factors of rapidly progressive CrGN included a combination of several factors such as: (i) a high frequency of crescents; (ii) frequent sclerosis and hyalinosis in the glomeruli with crescents; (iii) extensive tubulo-interstitial damage (cellular, fibrocellular and fibrous) in the renal cortex; (iv) hyperproteinuria; (v) high mean blood pressure; and (vi) anemia. Thus, the prognosis of CrGN is regulated by no single factor but instead by a complex combination of mutually associated factors.