Satoru Ogahara

Serum Lipoprotein (a) Levels in Maintenance Hemodialysis Patients

To further understand lipoprotein (a) [Lp(a)] and atherosclerosis, we measured serum Lp(a), lipoprotein, and apolipoprotein levels in 55 patients (males, 24-73 years old) on maintenance hemodialysis, and compared them with those of 82 controls (males, 21-81 years old). The serum Lp(a) levels in patients on maintenance hemodialysis were significantly higher than those of the normal controls, while serum total cholesterol (TC), high-density lipoprotein-cholesterol, (HDL-C), HDL2-C, HDL3-C, apolipoprotein (apo) Al, apo All levels, and lecithin-cholesterol acyltransferase (LCAT) activities were significantly (p < 0.05) reduced in the patient group. The frequency distribution of serum Lp(a) levels in the patients was different from that in the control group, and no prognostic tendency of serum Lp(a) levels was noted by the etiology of renal failure as histologically determined by the renal biopsies. In the patient group, we also found that serum Lp(a) levels negatively correlated with serum triglycerides (TG) and total protein (TP) concentrations (p < 0.05), but no correlation was found between the duration of hemodialysis therapy or patient age and the serum levels of TC, TG, apo B and Lp(a) levels when tested for simple regression. Significant (p < 0.05) positive correlations were also found between TP and serum TG, apo B, and LCAT activities. These opposing tendencies of Lp(a) and serum TG, apo B, when measured against TP concentrations, indicate that serum TP levels may not affect serum lipoprotein and Lp(a) levels in the same direction. These data suggest that hemodialysis or end-stage renal disease itself, rather than hypoproteinemia, may hold the key to high serum Lp(a) levels in hemodialysis patients.

Amelioration of diabetic nephropathy in OLETF rats by prostaglandin I(2) analog, beraprost sodium.

Background: Strict control of blood glucose and blood pressure levels sometimes fails to delay the development of diabetic nephropathy, and an effective therapy is not yet available. The present study aimed to examine whether the prostaglandin I2 analog beraprost sodium (BPS) ameliorates diabetic nephropathy in Otsuka Long-Evans Tokushima Fatty (OLETF) rat. Method: Fifty-week-old OLETF rats were divided into three groups according to treatment; 400 μg/kg body weight (BW) BPS, 200 μg/kg BW BPS, and 0.9% saline administration. Kidney histology, index of glomerulosclerosis, and glomerular volume were determined, and urine and serum chemistry were assessed. Results: The values for urine protein excretion and serum blood urea nitrogen in BPS-treated rats were significantly lower than those in untreated rats. In rats treated with 400 μg/kg BW BPS, neither sclerotic changes nor inflammatory cell infiltration were observed. Index of glomerulosclerosis and glomerular volume were also significantly reduced compared with untreated rats. Intriguingly, BPS reduced the level of serum triglyceride. In the glomerulus of treated rats, advanced glycation end product formation and macrophage influx were suppressed in a dose-dependent manner. Conclusion: These findings indicate that BPS has a therapeutic effect on diabetic nephropathy in the OLETF rat, which suggests a potential application of this drug in the treatment of human diabetic nephropathy.

The efficacy of incretin therapy in patients with type 2 diabetes undergoing hemodialysis

BackgroundAlthough incretin therapy is clinically available in patients with type 2 diabetes undergoing hemodialysis, no study has yet examined whether incretin therapy is capable of maintaining glycemic control in this group of patients when switched from insulin therapy. In this study, we examined the efficacy of incretin therapy in patients with insulin-treated type 2 diabetes undergoing hemodialysis.MethodsTen type 2 diabetic patients undergoing hemodialysis received daily 0.3 mg liraglutide, 50 mg vildagliptin, and 6.25 mg alogliptin switched from insulin therapy on both the day of hemodialysis and the non-hemodialysis day. Blood glucose level was monitored by continuous glucose monitoring. After blood glucose control by insulin, patients were treated with three types of incretin therapy in a randomized crossover manner, with continuous glucose monitoring performed for each treatment.ResultsDuring treatment with incretin therapies, severe hyperglycemia and ketosis were not observed in any patients. Maximum blood glucose and mean blood glucose on the day of hemodialysis were significantly lower after treatment with liraglutide compared with treatment with alogliptin (p < 0.05), but not with vildagliptin. The standard deviation value, a marker of glucose fluctuation, on the non-hemodialysis day was significantly lower after treatment with liraglutide compared with treatment with insulin and alogliptin (p < 0.05), but not with vildagliptin. Furthermore, the duration of hyperglycemia was significantly shorter after treatment with liraglutide on both the hemodialysis and non-hemodialysis days compared with treatment with alogliptin (p < 0.05), but not with vildagliptin.ConclusionsThe data presented here suggest that patients with type 2 diabetes undergoing hemodialysis and insulin therapy could be treated with incretin therapy in some cases.

Association of DQB1*0302 Alloantigens in Japanese Pediatric Patients with Steroid-Sensitive Nephrotic Syndrome

We identified human leukocyte alloantigens (HLA) class II alleles in 24 Japanese children with steroid-sensitive nephrotic syndrome (SSNS) by deoxyribonucleic acid (DNA) typing. The DQA1 and DQB1 alleles were identified using sequence-specific oligonucleotide probes for DQA and DQB. The frequency of DQB1*0302 was significantly higher in the patients than in the controls (54.0 vs. 16.0%, respectively; relative risk, RR = 6.2; pc < 0.00009. We also found that the frequency of DQA1*0103 in the patients was significantly lower than in the controls (RR = 0.194, pc < 0.04). Several studies have identified an association between certain HLA by serotyping. In the present study, we investigated the HLAs of Japanese patients with SSNS by DNA typing and observed a significant increase in the frequency of DQB1*0302 in patients with the disease. HLA-DQ3, which was proven to be associated with SSNS, consists of HLA DQ7, 8 and 9. DQB1*0302 is a component of HLA-DQ8. So we proposed the increase of DQ3 was due to an increase in DQ8.

Various Roles of Th Cytokine mRNA Expression in Different Forms of Glomerulonephritis

Background: Kidney disease is characterized by injurious immune responses to self or foreign antigens. The development and maintenance of immune responses generally involves activation of T lymphocytes. We evaluated mRNA expression patterns of T-cell cytokines to identify the principal Th-cell subset involved in the development of antineutrophil cytoplasmic antigen-associated pauci-immune crescentic glomerulonephritis (ANCAGN), membranoproliferative glomerulonephritis (MPGN), and membranous nephropathy (MN). Methods: Kidney biopsy specimens from ANCAGN (17), MPGN (11), and MN (14) patients were evaluated for mRNA expression of various T-cell cytokines. Results: Interferon-γ mRNA expression was detected in both ANCAGN and MPGN, but not in MN patients. Furthermore, mRNA expression of interleukin (IL)-12, a Th1-associated cytokine, was lower in MN patients than in ANCAGN and MPGN patients. In contrast, a significantly higher expression of IL-4 and IL-5 was observed in MN than in ANCAGN and MPGN patients. In the analyses of Th17-associated cytokine expression, a significantly higher expression of IL-6 and IL-17 was observed in ANCAGN than in MPGN and MN patients. No significant differences were observed in the expression of these cytokines between MPGN and MN patients. With regard to Treg-associated cytokines, a significantly higher IL-10 expression was observed in MN than in ANCAGN patients, and a significantly higher transforming growth factor-β expression was observed in MN than in ANCAGN and MPGN patients. Similarly, Foxp3 expression was significantly higher in MN. Conclusion: Th1 and Th17 immune responses in ANCAGN, the Th1 response in MPGN, and Th2 and Treg responses in MN patients may be integral for the distinct histological features of these diseases.

Suppression of Experimental Membranous Glomerulonephritis in Rats by an Anti-MHC Class II Antibody

Background: We previously reported that idiopathic membranous nephropathy (IMN) strongly correlated with HLA-DRB1*1501-DRB5*0101-DQAI*0102-DQB1* 0602, a specific haplotype of human major histocompatibility complex (MHC), in Japanese patients. To investigate the role of MHC in the development of rat Heymann nephritis (HN), an animal model of membranous nephropathy, a monoclonal antibody (mAb) specific to rat MHC class II antigen (RT1B) was administered, and its effectiveness in inhibiting HN was assessed. Methods: Active HN was induced in HN-sensitive Lewis rats by administering brush border proteins of rat proximal uriniferous tubules (FX1A). Rats were divided into four groups: rats treated with 1,000 µg anti-rat MHC class II mAb, rats treated with 100 µg anti-rat MHC class II mAb, rats treated with murine myeloma IgG, and rats that did not receive either FX1A or any other mAb. We examined the differences in 24-hour urinary protein excretion and serum alloantibody titers against FX1A between groups at different time intervals, and the histologic features of kidneys at the end of the study. Results: HN was induced in Lewis rats by inoculation with FX1A antigen. Administration of anti-MHC class II mAb successfully lowered urinary proteins, production of anti-FX1A alloantibodies, and the development of glomerular lesions in a dose-dependent manner. Conclusion: The present results demonstrated that the MHC class II molecule itself is directly involved in the pathogenesis of HN, and suggest that this therapy would be any better (or less toxic) than nonselective immunosuppressants in the treatment of IMN.

Association between HLA-DRB1*15 and Japanese patients with rheumatoid arthritis complicated by renal involvement.

We performed serological phenotyping of HLA antigens in 175 patients with rheumatoid arthritis (RA) with (n = 41) and without (n = 134) renal involvement (RI), and DNA typing of HLA class II alleles in 75 patients. Among the patients with RA, the frequency of serologically determined HLA-DR4 was found to be significantly increased (odds ratio: 1.8, confidence interval: 1.3–2.5, p = 2.4×10–4). In the patients without RI, the frequency of serological DR4 significantly increased (odds ratio: 2.2, confidence interval: 1.6–3.3, p = 2.6×10–5). On the other hand, among the patients with RI, a serological determinant, DR15, did significantly increase (odds ratio: 2.7, confidence interval: 0.9–8.4, p = 1.2×10–3) in comparison to the controls. At the DNA level, we found that the association of Japanese RA patients with serological HLA-DR4 was based on that with a genotype of HLA-DRB1*0405 (odds ratio: 2.4, confidence interval: 1.5–4.0, p = 4.4×10–4) and also found an association of HLA-DRB1*1501 (odds ratio: 2.8, confidence interval: 1.2–6.6, p = 0.017) with RA patients having RI. Our results confirmed the association of HLA-DRB1*04 with RA over the ethnic barrier at the DNA level. Our results also suggested a distinct genetic effect of HLA-DRB1*1501 in the aspect of the susceptibility of RI in RA.

A Prospective Observational Survey on the Long-Term Effect of LDL Apheresis on Drug-Resistant Nephrotic Syndrome

Background/Aims: LDL apheresis (LDL-A) is used for drug-resistant nephrotic syndrome (NS) as an alternative therapy to induce remission by improvement of hyperlipidemia. Several clinical studies have suggested the efficacy of LDL-A for refractory NS, but the level of evidence remains insufficient. A multicenter prospective study, POLARIS (Prospective Observational Survey on the Long-Term Effects of LDL Apheresis on Drug-Resistant Nephrotic Syndrome), was conducted to evaluate its clinical efficacy with high-level evidence. Methods: Patients with NS who showed resistance to primary medication for at least 4 weeks were prospectively recruited to the study and treated with LDL-A. The long-term outcome was evaluated based on the rate of remission of NS 2 years after treatment. Factors affecting the outcome were also examined. Results: A total of 58 refractory NS patients from 40 facilities were recruited and enrolled as subjects of the POLARIS study. Of the 44 subjects followed for 2 years, 21 (47.7%) showed remission of NS based on a urinary protein (UP) level <1.0 g/day. The UP level immediately after LDL-A and the rates of improvement of UP, serum albumin, serum creatinine, eGFR, and total and LDL cholesterol after the treatment session significantly affected the outcome. Conclusions: Almost half of the cases of drug-resistant NS showed remission 2 years after LDL-A. Improvement of nephrotic parameters at termination of the LDL-A treatment was a predictor of a favorable outcome.

Parasites alter the pathological phenotype of lupus nephritis

Abstract Lupus nephritis is one of the most serious complications of systemic lupus erythematosus and manifests with considerable phenotypic and histological heterogeneity. In particular, diffuse proliferative lupus nephritis (DPLN) and membranous lupus nephritis (MLN) represent morphologic forms that are polar opposites. DPLN is associated with autoimmune responses dominated by Th1 immune response associated with high levels of interferon (IFN)-γ. In contrast, a Th2 cytokine response is associated with the pathogenesis of MLN. MRL/lpr mice develop human LN-like immune complex-associated nephritis and provide a suitable histological model for human DPLN. Infection with Schistosoma mansoni skewed a Th2-type immune response induction and IL-10 in MRL/lpr mice, drastically changing the pathophysiology of glomerulonephritis from DPLN to MLN accompanied by increased IgG1 and IgE in the sera. T cells in 32-week-old MRL/lpr mice infected with S. mansoni expressed significantly more IL-4 and IL-10 than T cells of uninfected mice; T cells with IFN-γ were comparable between infected and uninfected MR/lpr mice. Thus, the helminthic infection modified the cytokine microenvironment and altered the pathological phenotype of autoimmune nephritis.

Relationship between Fluctuation Pattern of Blood Pressure during Hemodialysis Treatment and Cardiovascular Morphology: An Autopsy Study of 53 Cases

Background: Cardiovascular morphological changes are often conspicuous in autopsy examination of chronic hemodialysis (HD) patients. On the other hand, the fluctuation pattern in blood pressure (BP) during HD treatment varies from one patient to another. Cardiovascular changes may correlate with clinical findings including BP fluctuation patterns during HD, although no autopsy studies have previously examined this issue. Methods: In this study, 53 autopsies of patients who had been on chronic HD were reviewed. We determined the relationship between BP fluctuation during HD treatment along with stable and cardiovascular morphology, including heart weight, ventricular wall thickness, circumferences of the valves and the severity of aortic arteriosclerosis and coronary stenosis. Patients were divided into 4 groups according to the pattern of BP fluctuation during HD treatment at about 6 months before death: group 1 (n = 13), symptomatic hypotension and/or decline pattern during HD; group 2 (n = 11), continuously high BP during HD treatment; group 3 (n = 17), continuous normal BP during HD treatment, and group 4 (n = 12), continuously low BP without symptomatic hypotension during HD treatment. Results: Heart weight and ventricular wall thickness were greatest in group 2. The scores for aortic arteriosclerosis in groups 1 and 2 were higher than in groups 3 and 4. The coronary stenosis index was significantly higher in group 1 than in the other groups, and that in group 2 was higher than in group 4. Multiple regression analysis showed that age, HD duration and pulse pressure were independent variables for the score of arteriosclerosis, and the decline pattern of BP fluctuation during HD and pulse pressure were independent variables for coronary stenosis index. Conclusions: Our results suggest that certain clinical parameters including BP during HD may reflect cardiovascular morphological changes in stable HD patients, although further examination, such as 24-hour blood pressure measurement is recommended to elucidate the pathophysiology of cardiovascular diseases in HD patients.