Effects of Denosumab and Alendronate on Bone Health and Vascular Function in Hemodialysis Patients: A Randomized, Controlled Trial

Mineral and bone disorders including osteoporosis are common in dialysis patients and contribute to increased morbimortality. However, whether denosumab and alendronate are effective and safe treatments in hemodialysis patients is not known. Thus, we conducted a prospective, three-center study of 48 hemodialysis patients who were diagnosed as having osteoporosis and had not received anti-osteoporotic agents previously. Participants were randomized to either denosumab or intravenous alendronate, and all subjects received elemental calcium and calcitriol during the initial 2 weeks. The primary endpoint was the percent change in lumbar spine bone mineral density (LSBMD) at 12 months of treatment. The secondary endpoints included the following: change in BMD at other sites; change of serum bone turnover markers (BTM), coronary artery calcium score (CACS), ankle-brachial pressure index (ABI), brachial-ankle pulse wave velocity (baPWV), flow mediated dilation (FMD), and intima-media thickness at the carotid artery (CA-IMT); change from day 0 to day 14 in serum levels of Ca and P; time course of serum calcium (Ca), phosphorus (P), and intact parathyroid hormone (i-PTH); new fractures; and adverse events. Initial supplementation with elemental calcium and calcitriol markedly ameliorated the decrease of serum corrected calcium (cCa) levels induced by denosumab during the first 2 weeks, whereas serum cCa levels in the alendronate group were increased. Denosumab and alendronate markedly decreased serum levels of BTM and increased LSBMD at 12 months compared with baseline. However, no significant differences were found in the changes in LSBMD between the two groups. The serum cCa, P, and i-PTH levels in the two groups were maintained within the appropriate range. In contrast to the anti-osteoporotic effects, no significant differences after 12 months of treatment were found in the CACS, CA-IMT, ABI, baPWV, and FMD compared with pretreatment in both groups. Denosumab and alendronate treatment improved LSBMD, reduced BTM, and appeared to be safe in hemodialysis patients with osteoporosis. © 2019 American Society for Bone and Mineral Research.

Membranous nephropathy caused by rheumatoid arthritis

Membranous nephropathy (MN) caused by disease-modifying antirheumatic drugs is relatively common in patients with rheumatoid arthritis (RA). However, MN rarely occurs due to RA itself. We describe a 61-year-old woman with RA who showed nephrotic syndrome. She was admitted because of systemic edema and severe arthritis. She had a long history of RA successfully treated with methotrexate (MTX), but discontinued all treatments 4 years before hospitalization. She had never been treated with bucillamine or gold. Laboratory test results were positive for anti-cyclic citrullinated peptide antibody and negative for anti-nuclear antibody. Renal pathologic findings were compatible with MN. Immunofluorescence microscopy showed IgG, IgA, κ, λ, and C3 along the glomerular capillary wall, whereas deposition of IgM or C1q was not detected. In terms of the IgG subclasses, only IgG2 findings were positive. Results for glomerular antigen and serum antibody for M-type phospholipase A2 receptor and thrombospondin type 1 domain-containing 7A were negative. HLA type did not include the HLA-DQA1 gene that is a concern in primary MN (PMN). She responded to intensive immunosuppressive therapy consisting of prednisolone, tacrolimus, and MTX with a parallel reduction of proteinuria. Based on assessments for differentiating PMN from secondary MN (SMN), the diagnosis of the present case was incompatible with PMN. Taken together, we consider that SMN in the present case was due to RA itself rather than drug-induced MN.

Clinical significance of serum and mesangial galactose-deficient IgA1 in patients with IgA nephropathy

Introduction

Galactose-deficient IgA1 (Gd-IgA1) is a critical pathogenic factor for IgA nephropathy (IgAN), but its value as a disease-specific biomarker remains controversial. We aimed to clarify the clinical significance of Gd-IgA1 in patients with IgAN.

Methods

We retrospectively reviewed 111 patients who were diagnosed with IgAN based on the findings of renal biopsies (RB) at Showa University Hospital since 2007. Serum Gd-IgA1 (s-Gd-IgA1) at the time of RB was compared among 111 IgAN patients, 18 Henoch-Schönlein purpura nephritis (HSPN) patients, 29 lupus nephritis (LN) patients, 28 ANCA-associated vasculitis (AAV) patients, and 13 minimal change disease (MCD) patients using ELISA with an anti-human Gd-IgA1-specific monoclonal antibody (KM55). We also immunohistochemically stained paraffin-embedded sections for mesangial Gd-IgA1 (m-Gd-IgA1) deposition using KM55.

Results

Although levels of s-Gd-IgA1 were comparable among IgAN and HSPN, s-Gd-IgA1 levels were significantly elevated in patients with IgAN compared with LN, AAV and MCD (IgAN vs. HSPN, LN, AAV, and MCD: 16.2 ± 9.1 vs. 14.2 ± 10.8, p = 0.263; 12.7 ± 9.4, p = 0.008; 13.1 ± 7.3, p = 0.059; and 8.2 ± 4.8 μg/mL, p<0.001, respectively). Mesangial-Gd-IgA1 deposition was specifically detected in IgAN or HSPN. The increase in s-Gd-IgA1 significantly correlated with m-Gd-IgA1 positivity in patients with IgAN, and s-Gd-IgA1 elevation and m-Gd-IgA1 deposition were evident in patients with histopathologically advanced IgAN. Moreover, s-Gd-IgA1 levels were significantly higher in IgAN patients with glomerular sclerosis and tubulo-interstitial lesions. Mesangial-Gd-IgA1 intensity negatively correlated with eGFR in IgAN. Multivariate analysis selected s-Gd-IgA1 elevation as a significant risk factor for a 30%-reduction in eGFR in IgAN (HR, 1.37; 95% CI, 1.02–1.89; p = 0.038).

Conclusions

Although IgAN and HSPN remain difficult to differentiate, s-Gd-IgA1 elevation and m-Gd-IgA1 deposition are reliable diagnostic factors that reflect IgAN severity. Serum-Gd-IgA1 could serve as a predictor of renal outcomes in IgAN. Thus, Gd-IgA1 could be significant biomarker for patients with IgAN.

The effects of denosumab and alendronate on glucocorticoid-induced osteoporosis in patients with glomerular disease: A randomized, controlled trial

INTRODUCTION

The clinical utility of denosumab for the treatment of glucocorticoid-induced osteoporosis (GIOP) has yet to be established. This study aimed to compare the effects of denosumab on bone mineral density (BMD) and bone turnover markers to those of alendronate in patients with GIOP.

METHODS

A prospective, single-center study of 32 patients (18 men; median age, 66.0 years) with glomerular disease receiving prednisolone (PSL) who were diagnosed as having GIOP and had not received bisphosphonates before was conducted. Participants were randomized to either alendronate (35 mg orally once a week) or denosumab (60 mg subcutaneously once every 6 months), and all subjects received calcitriol. The primary endpoint was the percent change in lumbar spine (LS) BMD at 12 months of treatment.

RESULTS

The demographic and clinical characteristics at baseline were not significantly different between the groups. Denosumab treatment markedly decreased serum levels of t-PINP, BAP, and TRACP-5b at 12 months compared to baseline (-57.4%, p<0.001; -30.9%, p<0.01; -57.7%, p<0.001, respectively). After 12 months of alendronate treatment, serum levels of t-PINP, BAP, and TRACP-5b were also significantly decreased compared to pretreatment (-38.9%, p<0.01; -16.3%, p<0.05; -43.5%, p<0.01, respectively). However, no significant differences in the changes of bone turnover markers were found between the two groups. As for the effects on BMD, denosumab treatment markedly increased LS BMD from 6 months compared to baseline, whereas no significant difference compared to pretreatment was found in the alendronate group during the study period. In the comparison of the two groups, a large increase of LS BMD was found in the denosumab treatment group compared to the alendronate treatment group at 12 months (p<0.05).

CONCLUSIONS

In patients with GIOP, denosumab treatment markedly suppressed bone turnover, which led to a significantly greater increase in LS BMD than with alendronate treatment. These results suggest that denosumab is a therapeutic option for the treatment of GIOP.

Rituximab for the treatment of type B insulin resistance syndrome: a case report and review of the literature

BACKGROUND

Type B insulin resistance syndrome is a rare disease characterized by refractory transient hyperglycaemia and severe insulin resistance associated with circulating anti-insulin receptor antibodies. A standardized treatment regimen for type B insulin resistance syndrome has yet to be established.

CASE REPORT

We report the case of a 64-year-old man undergoing haemodialysis for antineutrophil cytoplasmic antibody-associated vasculitis and diabetic nephropathy, who developed rapid onset of hyperglycaemia (glycated albumin 52.1%). Type B insulin resistance syndrome was diagnosed, on the basis of positivity for anti-insulin receptor antibodies and the man's autoimmune history of antineutrophil cytoplasmic antibody-associated vasculitis and idiopathic thrombocytopenic purpura. Although severe hyperglycaemia persisted in spite of corticosteroids and high-dose insulin therapy, rituximab treatment resulted in remarkable improvement of the man's severe insulin resistance and disappearance of anti-insulin receptor antibodies without any adverse effects.

CONCLUSIONS

According to a literature review of 11 cases in addition to the present case, rituximab appears to be a safe and effective strategy for the treatment of corticosteroid-resistant type B insulin resistance syndrome.

Combination Therapy of Denosumab and Calcitriol for a Renal Transplant Recipient with Severe Bone Loss due to Therapy-Resistant Hyperparathyroidism

Denosumab (DMAb), a complete human type monoclonal antibody directed against the receptor activator of nuclear factor-κB ligand, has gained attention as a novel treatment for osteoporosis. However, its efficacy in patients with chronic kidney disease (CKD) remains unclear. We describe a 64-year-old man with severe bone loss and persistent secondary hyperparathyroidism (SHPT) after renal transplantation, whose condition failed to respond to conventional pharmacologic or surgical interventions. He underwent parathyroidectomy with left forearm autograft of crushed tiny parathyroid gland (PTG) particles. However, the autografted PTGs became swollen and caused persistent SHPT in spite of two additional parathyroidectomies of the left forearm. A single subcutaneous administration of DMAb induced hypocalcemia, which was corrected by calcium supplementation and high-dose calcitriol. Eventually, combination therapy with DMAb and calcitriol led to a decline in the patient's elevated serum parathyroid hormone levels, normalization of laboratory markers of bone metabolism, and improvement in bone mineral density in a short period of time. To the best of our knowledge, this is the first case report of severe bone loss with persistent SHPT in a renal transplant recipient effectively treated with the combination therapy of DMAb and vitamin D (VD). Although DMAb itself exerts no direct effects on PTGs, the DMAb treatment improved the patient's bone loss. In addition, administration of DMAb allowed for high-dose VD therapy which ultimately controlled SHPT and prevented DMAb-induced hypocalcemia. Therefore, this combination therapy might be a reasonable therapeutic strategy to reverse severe bone loss due to therapy-resistant SHPT in patients with CKD.

Anti-Phospholipase A2 Receptor (PLA2R) Antibody and Glomerular PLA2R Expression in Japanese Patients with Membranous Nephropathy

The phospholipase A2 receptor (PLA2R) is the major target antigen (Ag) in idiopathic membranous nephropathy (IMN). Recently, several types of immunoassay systems for anti-PLA2R antibody (Ab) have been developed. However, the correlation of serum anti-PLA2R Abs and glomerular expression of PLA2R Ag, and their association with clinicopathological characteristics have yet to be proven in Japanese patients. We examined serum anti-PLA2R Abs by both ELISA and cell-based indirect immunofluorescence assay (CIIFA), and glomerular PLA2R expression by immunofluorescence (IF) in 59 biopsy-proven MN patients including IMN (n = 38) and secondary MN (SMN) (n = 21). In this study, anti-PLA2R Abs were present in 50% of IMN patients, but was absent in SMN patients. The concordance rate between ELISA and CIIFA was 100%. Serum IgG levels were significantly lower in anti-PLA2R Ab-positive patients. Serum albumin levels correlated inversely with serum anti-PLA2R Ab titers. The prevalence and intensity of glomerular staining for IgG4 by IF were significantly higher in anti-PLA2R Ab-positive patients than in -negative patients. Glomerular PLA2 Ag expression evaluated by IF was positive in 52.6% of IMN patients, but was absent in SMN patients. The concordance rate between the prevalence of glomerular PLA2R Ag expression and anti-PLA2R Ab was 84.2%. The prevalence of anti-PLA2R Abs measured by ELISA/CIIFA was equivalent to previous Japanese studies evaluated using Western blotting. These analyses showed an excellent specificity for the diagnosis of IMN, and anti-PLA2R positivity was associated with some clinicopathological features, especially glomerular IgG4-dominant deposition.

Therapeutic effects and mechanism of conditioned media from human mesenchymal stem cells on anti-GBM glomerulonephritis in WKY rats

Recent studies have demonstrated that conditioned media derived from mesenchymal stem cells (MSC-CM) have therapeutic effects in various experimental diseases. However, the therapeutic mechanism is not fully understood. In the present study, we investigated the therapeutic effects and mechanism of MSC-CM in experimental antiglomerular basement membrane glomerulonephritis. We administered either MSC-CM or vehicle from day 0 to day 10 after the induction of nephrotoxic serum nephritis in Wistar-Kyoto rats. In vitro, we analyzed the effects of MSC-CM on TNF-α-mediated cytokine production in cultured normal human mesangial cells, proximal tubular (HK-2) cells, human umbilical vein endothelial cells, and monocytes (THP-1 and peripheral blood mononuclear cells). Compared with vehicle treatment, MSC-CM treatment improved proteinuria and renal dysfunction. Histologically, MSC-CM-treated rats had reduced crescent formation and glomerular ED1+ macrophage infiltration and increased glomerular ED2+ macrophage infiltration. Increased serum monocyte chemoattractant protein (MCP)-1 levels were observed in MSC-CM-treated rats. Renal cortical mRNA expression levels of proinflammatory cytokines, such as TNF-α and IL-6, and of the T helper cell 1 cytokine interferon-γ were greatly decreased by MSC-CM treatment. In vitro, pretreatment with MSC-CM blocked TNF-α-mediated IL-8 release in normal human mesangial cells and HK-2 cells. TNF-α-mediated MCP-1 release was enhanced by pretreatment with MSC-CM in human umbilical vein endothelial cells and HK-2 cells and was strikingly enhanced in THP-1 cells. Stimulation of peripheral blood mononuclear cells with a combination of MCP-1 and IL-4 enhanced the expression of M2-associated genes compared with IL-4 alone. We demonstrated that MSC-CM had therapeutic effects in experimental antiglomerular basement membrane glomerulonephritis that were mediated through anti-inflammatory effects that were partly due to acceleration of M2 macrophage polarization, which might be mediated by MCP-1 enhancement.

A Novel Mutation in a Japanese Family with X-linked Alport Syndrome

We herein report a novel mutation in a Japanese family with an X-linked Alport syndrome (AS) mutation in COL4A5. Patient 1 was a 2-year-old Japanese girl. She and her mother (patient 2) had a history of proteinuria and hematuria without renal dysfunction, deafness, or ocular abnormalities. Pathological findings were consistent with AS, and a genetic analysis revealed that both patients had a heterozygous mutation (c.2767G>C) in exon 32. In summary, the identification of mutations and characteristic pathological findings was useful in making a diagnosis of AS. For a close long-term follow-up, the early detection and treatment of women with X-linked AS are important.

Streptococcal Infection-related Nephritis (SIRN) Manifesting Membranoproliferative Glomerulonephritis Type I

We herein report the case of an 18-year-old boy who developed nephrotic syndrome and hypertension after upper airway inflammation. Post-streptococcal acute glomerulonephritis was diagnosed on the basis of a high antistreptolysin O titer, hypocomplementemia, proteinuria, and microscopic hematuria. A renal biopsy was performed due to persistent proteinuria, and the pathological diagnosis was membranoproliferative glomerulonephritis (MPGN) type I. Glomeruli showed positive staining for nephritis-associated plasmin receptor (NAPlr), a nephritogenic group A streptococcal antigen, and plasmin activity was found in a similar distribution as NAPlr deposition. This rare case of streptococcal infection-related nephritis (SIRN) manifesting MPGN type I supports the histological diversity of SIRN.

A case of sporadic medullary cystic kidney disease type 1 (MCKD1) with kidney enlargement complicated by IgA nephropathy

Medullary cystic kidney disease (MCKD) is a progressive tubulointerstitial nephropathy, and it leads to end-stage kidney disease (ESKD). It is an autosomal dominant inherited disease, and is categorized into two types according to the localizing chromosome and timing of ESKD onset. Its pathogenesis has not been revealed clearly, thus accumulation of the cases is very valuable. We report here the first reported case of MCKD with kidney enlargement complicated by IgA nephropathy. A 70-year-old male was admitted to our hospital because of renal dysfunction and bilateral kidney enlargement. He was diagnosed as having MCKD complicated by IgA nephropathy (IgA-N) by renal biopsy. We speculated that he had MCKD type 1 on the basis of the late onset of renal failure and no significant evidence of mutation in the UMOD gene that is associated with MCKD type 2. Thereafter, his kidney function decreased progressively and he started to receive hemodialysis. This is an interesting case of MCKD1 in terms of its sporadic nature, kidney enlargement, and complication of IgA-N.

Light-Chain Deposition Disease Successfully Treated with Bortezomib in an Elderly Patient: A Case Report and Review of the Literature

We herein report the case of an elderly patient with light-chain deposition disease (LCDD) successfully treated with bortezomib. An 83-year-old woman was admitted because of nephrotic syndrome. She was diagnosed to have monoclonal gammopathy of undetermined significance (IgG-κ type) and LCDD, on the basis of serum and urinary immunoelectrophoresis and renal biopsy. She responded to a modified regimen of bortezomib-based chemotherapy with disappearance of proteinuria without any adverse effects. According to a literature review of 16 cases, including the present case, bortezomib-based chemotherapy appears to be a convincing strategy for the treatment of LCDD even in elderly patients.

Epidermal growth factor receptor inhibition with erlotinib partially prevents cisplatin-induced nephrotoxicity in rats

The effects of blocking the epidermal growth factor receptor (EGFR) in acute kidney injury (AKI) are controversial. Here we investigated the renoprotective effect of erlotinib, a selective tyrosine kinase inhibitor that can block EGFR activity, on cisplatin (CP)-induced AKI. Groups of animals were given either erlotinib or vehicle from one day before up to Day 3 following induction of CP-nephrotoxicity (CP-N). In addition, we analyzed the effects of erlotinib on signaling pathways involved in CP-N by using human renal proximal tubular cells (HK-2). Compared to controls, rats treated with erlotinib exhibited significant improvement of renal function and attenuation of tubulointerstitial injury, and reduced the number of apoptotic and proliferating cells. Erlotinib-treated rats had a significant reduction of renal cortical mRNA for profibrogenic genes. The Bax/Bcl-2 mRNA and protein ratios were significantly reduced by erlotinib treatment. In vitro, we observed that erlotinib significantly reduced the phosphorylation of MEK1 and Akt, processes that were induced by CP in HK-2. Taken together, these data indicate that erlotinib has renoprotective properties that are likely mediated through decreases in the apoptosis and proliferation of tubular cells, effects that reflect inhibition of downstream signaling pathways of EGFR. These results suggest that erlotinib may be useful for preventing AKI in patients receiving CP chemotherapy.