Clinical and Pathological Significance of Autoantibodies to Erythropoietin Receptor in Type 2 Diabetic Patients With CKD

INTRODUCTION

We examined the impact of autoantibodies on the erythropoietin receptor (EPOR) in type 2 diabetic patients with chronic kidney disease (CKD).

METHODS

A total of 112 Japanese patients with type 2 diabetes who had CKD were enrolled in this study and followed for a mean of 45 months. Sera from these patients were screened for anti-EPOR antibodies using enzyme-linked immunosorbent assays.

RESULTS

Anti-EPOR antibodies were detected in 26 patients (23%). Anti-EPOR antibodies were associated with low hemoglobin concentrations and decreased renal function. In patients with biopsy-proven diabetic nephropathy, anti-EPOR antibodies were associated with increased levels of interstitial inflammation. A decrease in renal function was observed more frequently in patients with antibodies than in those without antibodies, and the presence of the antibodies together with well-known clinical parameters, including proteinuria and low glomerular filtration rate, was a significant risk factor for end-stage renal disease. In human tubular epithelial HK-2 cells, IgG fractions containing anti-EPOR antibodies upregulated the expression of monocyte chemoattractant protein-1 mRNA under a high concentration of glucose.

CONCLUSION

Anti-EPOR antibodies might be involved in the progression of renal lesions and in the impaired erythropoiesis in type 2 diabetic patients with CKD. Furthermore, the presence of anti-EPOR antibodies may be an additional predictor for end-stage renal disease in type 2 diabetes.

Nationwide multicenter kidney biopsy study of Japanese patients with hypertensive nephrosclerosis

BACKGROUND

Nephrosclerosis is an increasingly reason for dialysis in Japan. However, kidney biopsy specimens for hypertensive nephrosclerosis are very limited; thus, the pathologic evaluation of hypertensive nephrosclerosis currently remains unclear.

METHODS

Clinical and pathologic data of a total of 184 biopsy-confirmed hypertensive nephrosclerosis patients were collected from 13 centers throughout Japan. Seven pathological findings were assessed in this study. The outcomes of interest for this study were dialysis, composite kidney events, cardiovascular events, and all-cause mortality.

RESULTS

The Green and Yellow (G&Y), Orange, and Red groups of the chronic kidney diseases (CKD) heat map contained 36, 57, and 91 cases, respectively. The mean observation period was 7.3 ± 5.2 (median, IQR; 6.1, 2.6-9.7) years. Global glomerulosclerosis (GScle), interstitial fibrosis and tubular atrophy (IFTA), arteriolar hyalinosis in Red exhibited higher scores than those in G&Y and Orange. The incidence rates of the composite kidney end points in 100 person-years for the G&Y, Orange, and Red groups were 1.42, 2.16, and 3.98, respectively. In the univariate Cox analysis for the composite kidney end points, GScle, IFTA and interstitial cell infiltration exhibited statistically significant high hazard ratios (1.18, 1.84, 1.69, respectively). However, after adjustment for clinical and medication data, the Red group in the CKD heat map category was risk factor for the composite kidney end points (HR 9.51).

CONCLUSIONS

In summary, although pathologic findings had minor impacts on the prediction of composite outcomes in this study, the clinical stage of the CKD heat map is a good predictor of composite kidney events.

Clinicopathological analysis of biopsy-proven diabetic nephropathy based on the Japanese classification of diabetic nephropathy

BACKGROUND

The Japanese classification of diabetic nephropathy reflects the risks of mortality, cardiovascular events and kidney prognosis and is clinically useful. Furthermore, pathological findings of diabetic nephropathy are useful for predicting prognoses. In this study, we evaluated the characteristics of pathological findings in relation to the Japanese classification of diabetic nephropathy and their ability to predict prognosis.

METHODS

The clinical data of 600 biopsy-confirmed diabetic nephropathy patients were collected retrospectively from 13 centers across Japan. Composite kidney events, kidney death, cardiovascular events, all-cause mortality, and decreasing rate of estimated GFR (eGFR) were evaluated based on the Japanese classification of diabetic nephropathy.

RESULTS

The median observation period was 70.4 (IQR 20.9-101.0) months. Each stage had specific characteristic pathological findings. Diffuse lesions, interstitial fibrosis and/or tubular atrophy (IFTA), interstitial cell infiltration, arteriolar hyalinosis, and intimal thickening were detected in more than half the cases, even in Stage 1. An analysis of the impacts on outcomes in all data showed that hazard ratios of diffuse lesions, widening of the subendothelial space, exudative lesions, mesangiolysis, IFTA, and interstitial cell infiltration were 2.7, 2.8, 2.7, 2.6, 3.5, and 3.7, respectively. Median declining speed of eGFR in all cases was 5.61 mL/min/1.73 m²/year, and the median rate of declining kidney function within 2 years after kidney biopsy was 24.0%.

CONCLUSIONS

This study indicated that pathological findings could categorize the high-risk group as well as the Japanese classification of diabetic nephropathy. Further study using biopsy specimens is required to clarify the pathogenesis of diabetic kidney disease.

Prevalence of primary aldosteronism without hypertension in the general population: Results in Shika study

OBJECTIVE

Recent studies have reported a high prevalence of primary aldosteronism (PA) among hypertensive patients. However, few data exist regarding the prevalence of PA in the general population. Therefore, we examined the prevalence of PA in the general population including normotensive subjects.

METHODS

Plasma renin activity (ng/mL/hr), plasma aldosterone concentration (pg/mL) and aldosterone renin ratio (ARR) were determined in 309 subjects aged >40 years in Horimatsu and Higashi-Matsuho district, Shika-machi, Ishikawa, Japan.

RESULTS

Among them, 195 subjects (78 males, mean age: 62 ± 11 years) did not take antihypertensive agents: 113 normotensive subjects and 82 hypertensive subjects. Under these conditions, 68 subjects (13 males, age 62 ± 10 years) had an ARR >200. In 14 subjects who underwent captopril suppression test, PA was documented in 5 subjects, yielding a minimum prevalence of 2.6% in total subjects (1.8% in normotensive subjects and 3.7% in hypertensive subjects). Interestingly, females subjects demonstrated significant differences in ARR between subjects with age <50 (172 ± 105) and those with age 51-60 (388 ± 531), although there were no differences in male subjects.

CONCLUSIONS

These results demonstrate that PA including normotensive subjects exists more commonly than that expected in the general population. We suggest further investigation about the cause and progression of PA associated with sex and aging.

Inhibition of CTGF ameliorates peritoneal fibrosis through suppression of fibroblast and myofibroblast accumulation and angiogenesis

Peritoneal fibrosis (PF) is a serious complication in various clinical settings, but the mechanisms driving it remain to be fully determined. Connective tissue growth factor (CTGF) is known to regulate fibroblast activities. We therefore examined if CTGF inhibition has anti-fibrotic effects in PF. PF was induced by repetitive intraperitoneal injections of chlorhexidine gluconate (CG) in mice with type I pro-collagen promoter-driven green fluorescent protein (GFP) expression to identify fibroblasts. FG-3019, an anti-CTGF monoclonal antibody, was used to inhibit CTGF. CG-induced PF was significantly attenuated in FG-3019-treated mice. CG challenges induced marked accumulations of proliferating fibroblasts and of myofibroblasts, which were both reduced by FG-3019. Levels of peritoneal CTGF expression were increased by CG challenges, and suppressed in FG-3019-treated mice. FG-3019 treatment also reduced the number of CD31⁺ vessels and VEGF-A-positive cells in fibrotic peritoneum. In vitro studies using NIH 3T3 fibroblasts and peritoneal mesothelial cells (PMCs) showed that CTGF blockade suppressed TGF-β₁-induced fibroblast proliferation and myofibroblast differentiation, PMC mesothelial-to-mesenchymal transition, and VEGF-A production. These findings suggest that the inhibition of CTGF by FG-3019 might be a novel treatment for PF through the regulation of fibroblast and myofibroblast accumulation and angiogenesis.

Induction of humoral and cellular immune response to hepatitis B virus (HBV) vaccine can be upregulated by CpG oligonucleotides complexed with Dectin-1 ligand

A persistent hepatitis B virus (HBV) infection is characterized by a lack of or a weak immune response to HBV, which may be reflective of tolerance to HBV. Efficient induction of HBV-specific immune response leads to the clearance of HBV in patients with a chronic HBV infection. CpG oligodeoxynucleotides (ODN) has a powerful adjuvant effect in HBV vaccination. A recent report demonstrated that the immunization by B/K CpG ODN (K3) wrapped by the nonagonistic Dectin-1 ligand, schizophyllan (SPG), namely K3-SPG, was more effective in the induction of antigen-specific immune response than that by K3. In this study, we examined the efficacy of K3-SPG as a HBV vaccine adjuvant. Wild-type (WT) mice and HBV transgenic (HBV-Tg) mice were subcutaneously immunized with hepatitis B surface antigen (HBsAg) alone, HBsAg and K3, or HBsAg and K3-SPG. The vaccination with HBsAg and K3-SPG significantly enhanced humoral and cellular immune response to HBV antigen compared to the other vaccinations in WT and HBV-Tg mice. K3-SPG induced the accumulation of dendritic cells (DCs) into draining lymph node and the activation of DCs. The expression of cytokines and chemokines related to Th1 and Th2 responses was upregulated after the vaccination including with K3-SPG. In conclusion, these results indicated that the vaccination using K3-SPG may overcome tolerance even in patients with chronic HBV infection.

[A Novel Inhibitory Factor of Erythropoietin: Anti-Erythropoietin Receptor Antibody and Its Characteristics]

During the exploration of factors that interfere with the erythropoietin (EPO) -EPO receptor (EPOR) interaction in anemia, a novel inhibitory factor of EPO, anti-EPOR antibody, has been detected in anemic pa- tients with immune-mediated diseases. The study also demonstrated that the antibodies were observed in some patients with chronic kidney disease (CKD). EPOR is known to be expressed not only in bone mar- row erythroblasts, but also in other organs including the kidneys. In addition, previous studies showed that EPO may contribute to protecting the kidneys from injury by binding EPOR on renal resident cells as well as through the correction of anemia. Based on this background, we recently examined the clinical significance of anti-EPOR antibodies in patients with CKD. With regard to patients with lupus nephritis, who showed the highest antibody levels among the patients examined, the antibodies were associated with overall disease activity and cell infiltration in the injured kidney, and they were inversely related to the preserved renal function. Here, we discuss the discovery of anti-EPOR antibodies in patients with anemia and CKD, and the possibil- ity of their use as an additional biomarker for the deterioration of the renal function. [Review].

Effect of Autoantibodies to Erythropoietin Receptor in Systemic Lupus Erythematosus with Biopsy-proven Lupus Nephritis

OBJECTIVE

We examined the clinical significance of autoantibodies to the erythropoietin receptor (EPOR) in patients with systemic lupus erythematosus (SLE) who had biopsy-proven lupus nephritis (LN).

METHODS

Forty-six Japanese patients with SLE with LN who had undergone renal biopsy during 1993-2014 were enrolled in this study and followed for a mean of 83 months. Sera from those patients were screened for anti-EPOR antibodies using ELISA.

RESULTS

Anti-EPOR antibodies were detected in 18 (39%) of the 46 patients with SLE with anemia. Anti-EPOR antibodies were associated with low hemoglobin concentrations and reticulocytopenia. In addition, anti-EPOR antibodies were positively correlated with SLE disease activity, even though serum levels of the complement factors 3 and 4 did not differ between the 2 groups. In patients with International Society of Nephrology/Renal Pathology Society 2003 class IV LN, anti-EPOR antibodies were associated with active lesions including cellular crescents in glomeruli. Decrease in renal function was more frequently observed in patients without complete or partial renal response than in patients with it, and serum levels of the antibodies as well as renal response to treatment were significant risk factors for progression of renal dysfunction.

CONCLUSION

The present study suggests that anti-EPOR antibodies might be involved in overall disease activity and active renal lesions, as well as in the impaired erythropoiesis in patients with SLE with LN. Further, the levels of anti-EPOR antibodies may be an additional predictor for renal injury.

Risk factors associated with relapse or infectious complications in Japanese patients with microscopic polyangiitis

BACKGROUND

The prevention of relapse and infection complications during remission maintenance therapy is required to improve the prognosis of patients with microscopic polyangiitis (MPA) showing rapidly progressive glomerulonephritis (RPGN). The clinicopathological characteristics of patients with ANCA-positive MPA were examined to determine the risk factors for relapse or infectious complications after remission induction therapy.

PATIENTS AND METHODS

The study population consisted of 52 patients diagnosed as ANCA-positive MPA showing RPGN from 2002 to 2012, after publication of the Japanese guideline for RPGN. The clinicopathological findings were examined between the presence and absence of relapse or infectious complications.

RESULTS

The value of vasculitis damage index (VDI) was high for the relapse group and VDI value was identified as the leading factor associated with relapse [hazard ratio (HR) 3.36, 95 % confidence interval (CI) 1.58-7.12, P < 0.01]. On the other hand, the values of Birmingham Vasculitis Activity Score, clinical grade category of RPGN at diagnosis, and VDI at remission were high in the infectious group. Furthermore, clinical grade category of RPGN was the leading factor associated with infectious complications (HR 5.30, 95 % CI 1.41-19.9, P = 0.01).

CONCLUSION

The disease activity at diagnosis and severity of organ damage at remission were associated with relapse and infectious complications during remission maintenance therapy and infectious complication affected kidney survival and all-cause mortality in patients with ANCA-positive MPA exhibiting RPGN.

Association of PAX2 and Other Gene Mutations with the Clinical Manifestations of Renal Coloboma Syndrome

BACKGROUND

Renal coloboma syndrome (RCS) is characterized by renal anomalies and optic nerve colobomas. PAX2 mutations contribute to RCS. However, approximately half of the patients with RCS have no mutation in PAX2 gene.

METHODS

To investigate the incidence and effects of mutations of PAX2 and 25 candidate genes, patient genes were screened using next-generation sequence analysis, and candidate mutations were confirmed using Sanger sequencing. The correlation between mutations and clinical manifestation was evaluated.

RESULT

Thirty patients, including 26 patients (two families of five and two, 19 sporadic cases) with RCS, and 4 optic nerve coloboma only control cases were evaluated in the present study. Six PAX2 mutations in 21 probands [28%; two in family cohorts (n = 5 and n = 2) and in 4 out of 19 patients with sporadic disease] including four novel mutations were confirmed using Sanger sequencing. Moreover, four other sequence variants (CHD7, SALL4, KIF26B, and SIX4) were also confirmed, including a potentially pathogenic novel KIF26B mutation. Kidney function and proteinuria were more severe in patients with PAX2 mutations than in those without the mutation. Moreover, the coloboma score was significantly higher in patients with PAX2 gene mutations. Three out of five patients with PAX2 mutations had focal segmental glomerulosclerosis (FSGS) diagnosed from kidney biopsies.

CONCLUSION

The results of this study identify several new mutations of PAX2, and sequence variants in four additional genes, including a novel potentially pathogenic mutation in KIF26B, which may play a role in the pathogenesis of RCS.

Relationship between Serum Uric Acid Levels and Chronic Kidney Disease in a Japanese Cohort with Normal or Mildly Reduced Kidney Function

Background

Some observational studies have shown the relationships between hyperuricemia and chronic kidney disease (CKD); however, the threshold of serum uric acid (SUA) for deterioration of kidney function and the association between SUA and kidney injury by baseline kidney function remains unclear. This study aimed to clarify the relationships between SUA and reduced kidney function.

Methods

We analyzed a historical cohort of male Japanese individuals who underwent medical checkup between 1998 and 2007. Participants with baseline data and who were followed up for at least one year were included and stratified according to baseline kidney function. Kidney function was classified as normal [estimated glomerular filtration rate (eGFR) ≥ 90 ml/min/1.73 m²] or mildly reduced (eGFR 60–89 ml/min/1.73 m²). The outcome measured was kidney impairment defined as a decrease in eGFR to < 60 ml/min/1.73 m². Associations between SUA and risk for outcome and eGFR slopes were assessed.

Results

A total of 41632 subjects with mean age 45.4 years were included. During a mean follow-up of four years, 3186 (7.6%) subjects developed kidney dysfunction. Subjects with SUA ≥ 6.0 mg/dL had a significantly increased risk for kidney impairment compared with subjects with SUA of 4–4.9 mg/dL. SUA threshold levels were different according to baseline kidney function; SUA ≥ 7.0 and ≥ 6.0 mg/dL for normal and mildly reduced kidney function, respectively. Approximately the same trends were observed for eGFR slopes.

Conclusion

In the general population, hyperuricemia appears to be a risk factor for kidney impairment in males. For participants with mild kidney dysfunction, even a slight elevation of SUA can be a risk factor.

An autopsy case of vertebrobasilar dolichoectasia under hemodialysis due to autosomal dominant polycystic kidney disease

A 60-year-old male with end-stage kidney disease due to autosomal polycystic kidney disease began maintenance hemodialysis in 2005. A brain CT scan showed dilatation of left vertebral artery, basilar artery, bilateral post cerebral artery, and middle cerebral artery. At the time, he was diagnosed as vertebrobasilar dolichoectasia. He was once admitted to our hospital for ischemic stroke. After discharge, he was treated with anticoagulant agent from 2010 to 2012 without any new stroke events. In March, 2012, he was admitted to our hospital for an evaluation of diplopia and left hemiplegia. Brain MRI showed acute ischemia of bilateral pons and right temporal lobe. He was once recovered with urokinase and argatroban, but 3 months after admission, he died with sudden hypotension and impaired consciousness. Autopsy revealed that subarachnoid hemorrhage due to the rupture of basilar artery aneurysm was responsible for this event.

Impact of kidney function and urinary protein excretion on intima-media thickness in Japanese patients with type 2 diabetes

BACKGROUND

Carotid echo indexes [intima-media thickness (IMT)] are commonly used surrogate markers for cardiovascular disease; however, the impacts of chronic kidney disease (CKD) on changes in IMT are unclear. We examined associations between CKD and IMT in participants with and without type 2 diabetes through longitudinal analysis.

METHODS

In total, 424 subjects were enrolled in this study. IMT was measured as per carotid echo indexes. Relationships between IMT and risk factors were analyzed using multiple linear regression analysis, in which we defined IMT as the dependent variable and atherosclerosis-related factors (age, sex, systolic pressure, total cholesterol, body mass index, estimated glomerular filtration rate (eGFR), uric acid, smoking index, number of antihypertensive drugs, statin use, urinary protein levels, past cardiovascular event, glycated hemoglobin, and diabetes duration) as independent variables.

RESULTS

The study population was composed of 70.3 % male subjects. Participants with diabetes accounted for 64.4 % of the total population. The mean follow-up duration was 2.2 ± 1.5 years. Alterations in IMT tended to be associated with systolic blood pressure (+10 mmHg) (β = -0.0084, p = 0.09) and eGFR (+10 mL/min/1.73 m(2)) (β = -0.0049, p = 0.06) in all participants. In participants without diabetes, alterations in IMT were associated with eGFR (+10 mL/min/1.73 m(2)) (β = -0.0104, p = 0.03) and tended to be associated with systolic blood pressure (+10 mmHg) (β = 0.0094, p = 0.06). No significant relationships were found in participants with diabetes.

CONCLUSION

Low eGFR was associated with progression of carotid thickness independent of common cardiovascular risk factors in non-diabetic participants.

334 FACTORS AFFECTING HEMATOPOIETIC ENGRAFTMENT OF MONKEY EMBRYONIC STEM CELLS IN SHEEP FETUSES

Previously, we generated monkey/sheep haematopoietic chimeras by in utero transplantation (IUT) of monkey embryonic stem (ES); however, the factors that control how the ES cells successfully engraft and differentiate into haematopoietic tissue in sheep fetuses remain uncertain. Here, we examined factors that might influence donor cells and recipient sheep and affect successful ES cell engraftment. We transplanted either undifferentiated monkey ES cells or ES-derived cells at an early haematopoietic differentiation stage into sheep fetuses. The latter cells were allowed to differentiate by culturing on OP9 cell layers for 6 days. Cells were transplanted into the liver or subcutaneous tissue of recipient sheep fetuses at 43 to 50 or 51 to 67 days of gestation (full term = 147 days) using ultrasound to identify the site for transplantation. After birth, monkey haematopoietic engraftment in the bone marrow was analysed in 40 lambs using colony-PCR with cells grown in methylcellulose in the presence of defined cytokines; teratoma formation was analysed by biopsy and immunohistochemistry. We found that haematopoietic engraftment was only observed when ES-derived cells at the early differentiation stage were transplanted into fetal livers at 51 to 67 days of gestation (6/9). However, teratoma formation with mature monkey tissue structures was only observed following transplantation of undifferentiated ES cells into fetal subcutaneous tissues at 43 to 50 days of gestation (4/6), but that was not observed when both types of cells were transplanted into the liver (0/18) or at 51 to 67 days of gestation (0/24). These results demonstrate that the differentiation status of the donor cells, the transplantation site, and the age of the fetus at transplantation are important factors in engraftment and differentiation into haematopoietic tissue or teratoma formation in sheep fetuses.

312 EFFECTS OF TRANSFORMING GROWTH FACTOR ALPHA AND INSULIN-LIKE GROWTH FACTOR 1 SUPPLEMENTATION ON IN VITRO MATURATION OF CANINE OOCYTES

Although in vitro maturation (IVM) of oocytes has been successfully established for many species, the efficiency of IVM in canine oocytes is still very low. As growth factors have been shown to promote oocyte maturation in some species, we investigated whether use of transforming growth factor α (TGF-a) and insulin-like growth factor 1 (IGF-1) might overcome the difficulties of achieving meiotic maturation in cultured canine cumulus-oocyte complexes (COC). Ovaries were obtained from bitches at 6 months to 7 years of age by ovariohysterectomy and were sliced repeatedly to release COC. In the first experiment, the COC were cultured at 38.8°C for 48 h in 5% CO2 in air in medium 199 supplemented with either TGF-a (0, 1, 10, or 100 ng mL–1) or IGF-1 (0, 0.5, 5, 10, or 50 µg mL–1). In the second experiment, the synergistic effect of TGF-a and IGF-1 was investigated by culturing COC in medium 199 supplemented with both TGF-a (0, 1, 10, or 100 ng mL–1) and IGF-1 (0, 0.5, 5, 10, or 50 µg mL–1). At the end of the culture period, the oocytes were denuded of cumulus cells by pipetting with a fine bore glass pipette; the denuded oocytes were then fixed in Carnoy's solution and stained with Hoechst 33342. The nuclear configuration and chromatin morphology of the oocytes were evaluated under confocal laser scanning microscopy. The cells were assigned to 1 of the following meiotic stages: germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase I (MI), or metaphase II (MII). Data were analysed by ANOVA with Fisher's PLSD test. In experiment 1, no significant difference were observed in the rates of cells maturing to the MI and MII stages, but that in the 10 ng mL–1 of TGF-a group (56.3%) were larger than in the other treatment groups (38.8–51.0%). The frequencies of MII stage cells in the 5, 10, and 50 µg mL–1 of IGF-1 treatment groups (9.8, 13.3, and 12.2%, respectively) were significantly higher than in the 0.5 µg mL–1 of IGF-1 group and the control group (5.3 and 2.2%, respectively). In experiment 2, the frequency of MI and MII cells in the control, 1 ng mL–1 of TGF-a plus 0.5 µg mL–1 of IGF-1, 10 ng mL–1 of TGF-a plus 5 µg mL–1 of IGF-1, 10 ng mL–1 of TGF-a plus 10 µg mL–1 of IGF-1, and 100 ng mL–1 of TGF-a plus 50 µg mL–1 of IGF-1 group were 44.1, 36.1, 63.5, 70.8, and 50.8%, respectively. The frequency of MII cells in the control group and the same treatment groups were 2.8, 7.2, 10.4, 15.3, and 10.8%, respectively. Both frequencies in the 10 ng mL–1 of TGF-a plus 10 µg mL–1 of IGF-1 group were significantly higher than in the control group. The TGF-a may act in a paracrine fashion on the surrounding granulosa cells, and IGF-1 may play multiple roles in cellular metabolism, proliferation, growth, and differentiation in canine oocyte maturation, as has been reported for many other species. In conclusion, these results demonstrate that a synergistic effect between TGF-a and IGF-1 produces an increased rate of in vitro maturation to the MI and MII stages in canine oocytes.

New Governmental Regulatory System for Stem Cell-Based Therapies in Japan

Regenerative medicine using stem cells is expected to provide tools for the replacement or repair of damaged tissues, opening up the possibility of treating many diseases that cannot otherwise be effectively treated. To promote the development of and access to regenerative medicine, it is important to take a balance of expedited provision of innovative therapies and appropriate steps to ensure safety and efficacy. While most developed countries have various regulatory frameworks for clinical trials and medical treatments involving stem cells, the Act on the Safety of Regenerative Medicine and the Revised Pharmaceutical Affairs Law have recently been simultaneously passed by the Japanese Diet. According to the former act, these medical technologies are categorized into 3 classes depending on their anticipated potential risk to human health, and the specific procedures falling into each class are determined. In addition, the act enables medical institutions to commission cell processing by business facilities outside the institution (even foreign facilities) that fulfill the requirements set out by the Ministry of Health, Labour and Welfare, with the aim to promote collaboration between academia and industry from an early stage. According to the latter law, a therapeutic product for regenerative medicine is defined as a product distinct from pharmaceuticals and medical devices, enabling regenerative medical products to be given a conditional, time-limited marketing authorization much earlier than that under the previous system. The new legal framework of regenerative medicine is expected to achieve the aim to develop and promote regenerative medicine, aiming at timely provision of safe and effective therapies and products.