[Case of anti-glomerular basement membrane antibody nephritis in a patient who was able to withdraw from dialysis and gave birth twice but underwent living renal transplantation due to progression to end-stage renal failure 15 years after onset].

A 34-year-old woman with suspected rapidly progressive glomerulonephritis had been admitted to our hospital in March 1993 at the age of 19 years. Renal biopsy revealed cellular crescent formation in 24 of 26 glomeruli. Serum examination was positive for anti-glomerular basement membrane (GBM) antibody, while pulmonary hemorrhage was absent. Based on these findings, she was diagnosed with anti-GBM antibody nephritis, and treated with corticosteroid pulse therapy and double filtration plasmapheresis (DFPP) in addition to hemodialysis (HD). HD was withdrawn within 2 months. Wishing to have a baby, she had delivery in 1997 and 2000. Subsequently, her renal function gradually decreased, and she underwent an ABO-incompatible living-donor kidney transplant, with her husband as the donor, in March 2008. She has been making good progress after transplantation. Anti-GBM antibody nephritis has a poor prognosis, but renal function was maintained for 15 years in this patient, who responded well to the initial treatment. The underlying disease rarely recurs if transplantation is performed after the patient has become negative for anti-GBM antibody, anti-GBM antibody nephritis therefore seems to be a good indication for treating patients with renal transplantation.

[Anti-MuSK antibody-positive myasthenia gravis with nephrotic syndrome: a case report].

A 40-year-old man was admitted to our hospital because of dysarthria, difficulty swallowing, double vision and weakness of both upper extremities. There were no detectable anti-AChR antibodies. He was diagnosed with seronegative myasthenia gravis (SNMG) based on a positive edrophonium test and positive waning on repetitive stimulation. Thereafter serological examination detected anti-muscle-specific kinase (MuSK) antibodies and he was diagnosed with anti-MuSK antibody-positive MG. Three years after the onset, the patient developed rapidly progressing respiratory failure and fever. He was diagnosed with aspiration pneumonia caused by swallowing difficulty. He was treated with mechanical ventilation, plasma exchange and antibiotics. Laboratory tests on admission also demonstrated nephrotic syndrome. Renal biopsy specimens showed diffuse thickening of the basement membrane by PAS and PAM stain, and granular immunofluorescent deposits of IgG4 along the glomerular capillary walls. Therefore, he was also diagnosed with membranous nephropathy in addition to anti-MuSK antibody-positive MG. MG is sometimes complicated with nephrotic syndrome, however there has been no report of anti-MuSK-antibody positive MG complicated with nephrotic syndrome. It has been reported that anti-MuSK-antibodies are IgG4 and that membranous nephropathy is suggested to be an IgG4 mediated disease. Our findings suggest that IgG4 may play an important role in the pathogenesis of our patient.

Hepatocyte growth factor prevents peritoneal fibrosis in an animal model of encapsulating peritoneal sclerosis.

BACKGROUND: Ultrafiltration failure associated with peritoneal fibrosis can lead patients to discontinue continuous ambulatory peritoneal dialysis (CAPD). It has been reported that the reciprocal imbalance between transforming growth factor-beta1 (TGF-beta1) and hepatocyte growth factor (HGF) is closely involved in the progression of tissue fibrosis. We previously showed that exogenous HGF restores the growth of human peritoneal mesothelial cells suppressed by a high concentration of D-glucose or TGF-beta1. In this study, we examined whether constitutive exposure to HGF prevents peritoneal fibrosis in an animal model of encapsulating peritoneal sclerosis (EPS). METHODS: To establish the model, a daily intraperitoneal injection of 0.1% chlorhexidine gluconate was given to male Wister rats for 35 days. Rat peritoneal mesothelial cells (RPMCs) transfected with full-length human HGF cDNA in an expression vector (pUCSRalpha/HGF) were injected into the peritoneal cavity of the rats. Thereafter, pathological changes to the peritoneal membrane were observed, and the effect on peritoneal ultrafiltration volume was examined. RESULTS: In the model, microscopic examination revealed a progressive thickening of the submesothelial layer, and an increase in the number of capillary vessels. Peritoneal ultrafiltration volume was decreased. Interestingly, the pathological changes to the peritoneal membrane were reversed by the intraperitoneal injection of pUCSRalpha/HGF-transfected RPMCs. Furthermore, peritoneal ultrafiltration volume was increased. CONCLUSIONS: The constitutive production of HGF by UCSRalpha/HGF-transfected RPMCs can improve peritoneal fibrosis resulting in an increase in peritoneal ultrafiltration volume. This approach may have clinical application.

Possible effects of hepatocyte growth factor for the prevention of peritoneal fibrosis.

OBJECTIVE: Some patients who had carried out long-term continuous ambulatory peritoneal dialysis discontinued the treatment because of progressive peritoneal fibrosis. It has been previously reported that transforming growth factor-beta1 (TGF-beta1) is one of the factors that induces peritoneal fibrosis. Also, hepatocyte growth factor (HGF) plays a role in the prevention of fibrosis and in inhibiting TGF-beta1 production. In this study, we examined the effects of HGF on peritoneal fibrosis by TGF-beta1 induced by high concentrations of D-glucose. DESIGN: We transfected a full-length human HGF cDNA in an expression vector into human peritoneal mesothelial cells (HPMCs) using the calcium phosphate method. Transfected HPMCs were cultured with high concentrations of D-glucose solution and co-cultured with fibroblasts using a transwell system. Cell proliferation was determined using the Tetra Color One method. TGF-beta1 and HGF protein were measured by enzyme-linked immunosorbent assay. RESULTS: In addition to recombinant HGF, the growth inhibition of HPMCs by high concentration D-glucose or TGF-beta1 was significant. By transfecting HGF cDNA into HPMCs, growth inhibition by high concentration D-glucose was completely restored. Furthermore, the production of TGF-beta1 was also significantly decreased. CONCLUSION: These results suggested that exogenous HGF could possibly prevent peritoneal fibrosis.

Mutant type glutathione S-transferase theta 1 gene homologue to mTOR in myelodysplastic syndrome: possible clinical application of rapamycin.

In this study, we observed the expression of the GSTT-1 gene in patients with myelodysplastic syndrome (MDS) at the messenger RNA level. Reverse transcription-polymerase chain reaction (RT-PCR) for GSTT-1 was performed with a pair of primers complementary to the 5' coding section and the 3' coding section of the GSTT-1 cDNA for amplifying the 623-bp band. Among 20 patients with MDS, 8 patients showed the expected 623-bp band on RT-PCR, and 12 patients showed a 500-bp band on RT-PCR, indicating that a 123-bp sequence was deleted as a mutant of the GSTT-1 gene. Furthermore, a BLAST DNA search showed that the deletion of a 123 bp sequence creates a sequence that is 63% homologous to human FKBP-rapamycin associated protein (FRAP); this protein has been termed a mammalian target of rapamycin (mTOR). We respectively transfected the wild type and the mutant type GSTT-1 gene in an expression vector to two cell lines (K562 and HL-60). The stable transformants for the wild type and the mutant type GSTT-1 genes were made by G418 selection. Interestingly, rapamycin could induce significant growth inhibition of the stable transformants for mutant type GSTT-1, which was indicative of apoptosis, but not that of those for wild type GSTT-1. These results suggest that rapamycin could be included in the therapeutic modality for the patients with MDS who have the mTOR sequences in GSTT-1 gene.

Involvement of TGF-beta signal for peritoneal sclerosing in continuous ambulatory peritoneal dialysis.

BACKGROUND: Functional failure of the peritoneal membrane is the most serious problem in long-term continuous ambulatory peritoneal dialysis (CAPD). Transforming growth factor-beta (TGF-ss) is one of the key mediators of fibrosis in some organs, and is thought to be involved in peritoneal alterations. In this study, we examined the role of TGF-beta1/TGF-ss receptors for human peritoneal mesothelial cells (HPMCs) and fibroblasts, and their interactions in CAPD patients. METHODS: HPMCs were cultured for 48 h in a medium containing normal- dose glucose (7 mM), high-dose glucose (30 mM) and mannitol as an osmotic agent, equal to 30 mM glucose. Cell proliferation was observed using the Tetra Color One assay. The concentration of TGF-beta1 in culture supernatants was measured by enzyme-linked immunosorbent assay (ELISA). The expression of TGF-ss receptor types I and II was observed by flow cytometry. HPMCs and fibroblasts were co-cultured and assayed using transwell inserts in order to identify the effects of the high-concentration glucose solution. RESULTS: HPMC proliferation was inhibited by the high concentration of glucose but not by mannitol. The inhibition was abrogated by the neutralizing antibody for TGF-beta1. TGF-beta1 was induced by a high concentration of glucose but not by mannitol. The expression of both TGF-ss receptors was augmented in culture with the high concentration of glucose but not with mannitol. In the co-culture assay, the number of HPMCs was decreased and fibroblasts were significantly increased in culture with the high concentration of glucose. CONCLUSIONS: A high concentration of glucose induced a large amount of TGF-beta1 and enhanced the expression of TGF-ss receptors. HPMCs were sensitive to TGF-beta1 in response to a high concentration of glucose. These data suggest that TGF-beta1 from HPMCs exposed to a high concentration of glucose down-regulates the proliferation of HPMCs and accelerates peritoneal fibrosis.

[Possible role of soluble erythropoietin receptors in renal anemia].

Recombinant human erythropoietin(rHuEpo) is effective for the treatment of renal anemia associated with chronic renal failure(CRF). However, we have encountered some patients with CRF who have sometimes developed a resistance to rHuEpo. This resistance can be due to iron or folate deficiency, aluminum toxicity, hyperparathyroidism, or auto-antibodies for rHuEpo. In this study, we focused on the soluble erythropoietin receptor(sEpoR), which can bind to rHuEpo. To demonstrate the possibility that the sweeping of rHuEpo by sEpoR results in resistance to rHuEpo, we performed a bioassay using the rHuEpo-dependent cell line, UT7/EPO. The results showed that recombinant mouse sEpoR(rmsEpoR) can reduce the proliferation of UT7/EPO induced by rHuEpo in a dose-dependent manner. We consider that this cell line could be a useful tool in a bioassay to detect the inhibitory factor(s) against Epo. We selected sera from three groups of patients with renal anemia associated with CRF who were receiving hemodialysis three times a week: the first was a patient group that needed a high dose of rHuEpo(7,500-9,000 unit/dialysis), the second was a patient group that needed an intermediate dose of rHuEpo (4,500 unit/dialysis), the third was a patient group that needed a low dose of rHuEpo(below 1,500 unit/dialysis). Interestingly, the proliferation of UT7/EPO determined with [3H]-thymidine incorporation was reduced by the addition of sera from the first group, but not by the addition of sera from the third group. These results suggested that serum sEpoR may play an important role in signal transduction via EpoR on erythroid progenitor in CRF patients.