Hideki Wakui

Effects of Denosumab on Bone Metabolic Markers and Bone Mineral Density in Patients Treated with Glucocorticoids

Objective We performed a prospective study to determine the efficacy and safety of denosumab on bone metabolic indices and bone mineral density (BMD) in 29 patients receiving long-term glucocorticoids (GCs) who had clinical risk factors for fracture. Methods Among these patients, 16 had systemic lupus erythematosus (SLE), 6 RA, 4 other autoimmune diseases, and 3 renal diseases. All patients received donosumab 60 mg at baseline and 6 months. Serum N-terminal cross-linked telopeptide of type I collagen (NTX) and bone-specific alkaline phosphatase (BAP) levels were measured as bone metabolic indices. BMD at the lumbar spine (LSBMD) and femoral neck (FNBMD) were measured using dual energy X-ray absorptiometry and expressed as a percentage of the young adult mean (%YAM). Results Denosumab therapy significantly reduced serum NTX and BAP levels from baseline after 12 months (from 19.2 to 13.9 nmol BCE/L; from 11.9 to 9.2 U/L, respectively). In 18 patients treated with bisphosphonates before the start of denosumab therapy, the improvements in the LSBMD and FNBMD values were 1.5%YAM/year and 1.1%YAM/year, respectively. The LSBMD and FNBMD values were both significantly higher 12 months after denosumab therapy (3.5%YAM/year and 3.0%YAM/year, respectively). The LSBMD gain was significantly higher after denosumab therapy than during bisphosphonate therapy. No fractures were observed in any patients during denosumab therapy. Conlusion Denosumab is effective and safe in preventing bone resorption and BMD loss in patients treated with long-term GCs for inflammatory diseases. This is the first study showing a significant increase in not only LSBMD but also FNBMD in GC-induced osteoporosis after denosumab therapy.

Validation of the 2010 histopathological classification of ANCA-associated glomerulonephritis in a Japanese single-center cohort

Abstract Objectives. To validate the 2010 histopathological classification system of anti-neutrophil cytoplasmic antibodies (ANCA)-associated glomerulonephritis (GN) in a Japanese single-center cohort. Methods. We retrospectively studied 54 patients (28 renally limited pauci-immune GN, 25 microscopic polyangiitis, and one Churg–Strauss syndrome). Results. There were 17 patients with focal GN, eight patients with crescentic GN, 19 patients with mixed GN, and 10 patients with sclerotic GN. Detailed information regarding treatment was available in 39 patients. All these patients were treated with steroids with or without immunosuppressive agents. Hemodialysis was introduced in two patients with crescentic GN and three patients with sclerotic GN. During the follow-up period, 27 of 54 patients died. The major cause of death was pneumonia. Significant differences were observed in estimated glomerular filtration rate among patients with focal, crescentic, mixed, and sclerotic GN at entry and 1- and 5-year follow-up. Patients with focal GN had preserved renal function and favorable outcome. Conclusions. Our validation study suggests that the 2010 histopathological classification of ANCA-associated GN might aid in prognostication of patients at the time of diagnosis and in therapy selection.

ATPase activity and ATP-dependent conformational change in the co-chaperone HSP70/HSP90-organizing protein (HOP).

Background: HOP assists protein transfer in the HSP70- and HSP90-dependent protein-folding pathway. Results: HOP hydrolyzed ATP, and the region containing amino acids 1–359 (TPR1-TPR2A) was required for hydrolysis and direct interaction with ATP. Conclusion: HOP has slow ATPase activity and changes its conformation upon ATP hydrolysis. Significance: This is the first demonstration of the ATPase activity of HOP, and may enhance our understanding of the physiological function. Co-chaperones help to maintain cellular homeostasis by modulating the activities of molecular chaperones involved in protein quality control. The HSP70/HSP90-organizing protein (HOP) is a co-chaperone that cooperates with HSP70 and HSP90 in catalysis of protein folding and maturation in the cytosol. We show here that HOP has ATP-binding activity comparable to that of HSP70/HSP90, and that HOP slowly hydrolyzes ATP. Analysis of deletion mutants revealed that the ATPase domain of HOP is in the N-terminal TPR1-DP1-TPR2A segment. In addition, HOP changes its conformation in the presence of ATP. These results indicate that HOP is a unique co-chaperone that undergoes an ATP-dependent conformational change.

Serum interleukin 6 levels as a useful prognostic predictor of clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease

Abstract Objectives. Rapidly progressive interstitial lung disease (RP-ILD) is life-threatening in patients with clinically amyopathic dermatomyositis (CADM). Useful prognostic markers are necessary for treatment selection. This study aimed to investigate differences in clinical and laboratory characteristics between surviving and non-surviving patients. Methods. Twelve CADM patients with RP-ILD were enrolled. Six patients lived (Group A) and six patients died (Group B) after immunosuppressive treatment for RP-ILD. Clinical manifestations and laboratory data before treatment were compared between the two groups. Results. Among the clinical manifestations and laboratory data examined, serum interleukin 6 (IL-6) levels in Group B were significantly higher than those in Group A (mean ± SD 28.5 ± 21.0 vs. 7.2 ± 1.6 pg/mL; p = 0.009). Simple regression analysis showed that serum IL-6 was the only significant prognostic factor (p = 0.032). Kaplan–Meier estimates showed that the cumulative survival rate was significantly lower in patients with serum IL-6 levels of ≥ 9 pg/mL than in patients with those of < 9 pg/mL (p = 0.04). Conclusions. Serum IL-6 levels may predict the prognosis of CADM patients with RP-ILD. The intensity of immunosuppressive treatment can be decided according to serum IL-6 levels at an early phase of the disease.

Relapsing Polychondritis with Encephalitis: A Case Report and Literature Review

We herein report the case of a 39-year-old man who developed bilateral auricular chondritis, conjunctivitis, and central neurological symptoms. He was diagnosed with encephalitis associated with relapsing polychondritis (RP) based on the findings of an ear cartilage biopsy, cerebrospinal fluid examination and magnetic resonance imaging. Although oral prednisolone (60 mg/day) was administered, the initial steroid therapy did not improve his symptoms. In contrast, methylprednisolone (mPSL) pulse therapy followed by prednisolone gradually ameliorated his condition. There were no episodes of recurrence during the two-year follow-up period. A review of the literature revealed that meningoencephalitis and encephalitis are rare, but important, complications of RP responsive to mPSL pulse therapy.

Membranous nephropathy with monoclonal IgG4 deposits and associated IgG4-related lung disease

A 62-year-old woman was admitted for nephrotic syndrome and lung tumor. A renal biopsy showed membranous features of the glomeruli. Immunofluorescence studies revealed granular IgG4-κ deposits along with the glomerular basement membrane. Electron microscopy revealed granular electron-dense deposits. Further study denied multiple myeloma. Light microscopy of the resected lung tumor revealed IgG4-related lung disease with no malignancy. Steroid therapy induced a remission of the nephrotic syndrome, with no recurrence of the lung tumor. We consider that this is the first case of a proliferative glomerulonephritis with monoclonal IgG deposits of IgG4 subclass, and a rare concurrence with IgG4-related disease.

Two Cases of Thrombocytopenia, Anasarca, Fever, Reticulin Fibrosis/Renal Failure, and Organomegaly (TAFRO) Syndrome with High Serum Procalcitonin Levels, Including the First Case Complicated with Adrenal Hemorrhaging

Thrombocytopenia, Anasarca, Fever, Reticulin fibrosis/Renal failure, and Organomegaly (TAFRO) syndrome is a recently described systemic inflammatory disorder characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis/renal failure, and organomegaly. It has an acute or subacute onset of unknown etiology, although some pathological features resemble those of multicentric Castleman disease. We here report two cases of TAFRO syndrome. The symptoms and pathological findings in these cases met the 2015 diagnostic criteria. Our cases showed high serum procalcitonin levels, suggesting bacterial infection as an onset trigger. In addition, Case 1 is the first case complicated with adrenal hemorrhaging. Case 2 is the second case of tocilizumab-resistant TAFRO syndrome successfully treated with rituximab.

Novel antimicrobial activities of a peptide derived from a Japanese soybean fermented food, Natto, against Streptococcus pneumoniae and Bacillus subtilis group strains

We recently isolated a tumoricidal peptide from Natto, a Japanese traditional fermented food. In the present study, antimicrobial activity of the Natto peptide was examined. The peptide consisted of 45 amino acid residues, and its structure was predicted to be rich in α-helix. It excreted antimicrobial activity only against Streptococcus pneumoniae and Bacillus subtilis group (B. subtilis, Bacillus pumilus, and Bacillus licheniformis). Lesser antimicrobial activity was observed for Streptococcus species other than S. pneumoniae. Hemolysate or hemin was required for the antimicrobial activity of the peptide. The Natto peptide damages the cell membrane of B. subtilis. On the other hand, chain morphology was induced in S. pneumoniae, which is naturally diplococcus, during the early phases of the Natto peptide treatment; following that the cells were rapidly lysed. This suggested that the Natto peptide displayed a novel narrow spectrum of bactericidal activity and inhibited cell separation during cell division of S. pneumoniae.

Similarity and differences in the physicochemical properties of lactate dehydrogenase isozymes from different tissues of Japanese sandfish Arctoscopus japonicus

Vertebrates have three genes (LDHA, LDHB, and LDHC) encoding skeletal muscle-, heart muscle- and testis-specific lactate dehydrogenase (LDH, E.C. 1.1.1.27), respectively. The muscle and heart LDHs are tetramers formed by polypeptides encoded by LDHA and LDHB, but not LDHC. The catalytic activity and physicochemical characteristics of testis LDH (tLDH) differs from those of the other two isozymes. There have been few kinetic analyses of fish tLDH. Moreover, the mechanism enabling enzymatic activity to be sustained in low temperature-adapted fish remains unclear. In the present study, tLDH and white muscle LDH (mLDH) were isolated from the Japanese sandfish Arctoscopus japonicas, the habitat of which ranges from 1.5 to 13xa0°C in temperature. The Km and Vmax of mLDH and tLDH with pyruvate were similar, but their thermostabilities differed. The of Km and Vmax values increased with increasing temperature between 5 and 40xa0°C, and the van’t Hoff ΔH values for pyruvate reduction by mLDH and tLDH were 35 and 31xa0kJxa0mol−1, respectively. Our findings indicate that LDH function and structure (thermal stability) are highly conserved in skeletal muscle and testis, but unique properties are acquired in each tissue depending on its function.

Hydroxychloroquine binding to cytoplasmic domain of Band 3 in human erythrocytes: Novel mechanistic insights into drug structure, efficacy and toxicity

Hydroxychloroquine (HCQ) is a widely used drug in the treatment of autoimmune diseases, such as arthritis and systemic lupus erythematosus. It has also been prescribed for the treatment of malaria owing to its lower toxicity compared to its closely related compound chloroquine (CQ). However, the mechanisms of action of HCQ in erythrocytes (which bind preferentially this drug) have not been documented and the reasons underlying the lower side effects of HCQ compared to CQ remain unclear. Here we show that, although the activity of erythrocyte lactate dehydrogenase (LDH), but not GAPDH, was inhibited by both HCQ and CQ inxa0vitro, LDH activity in erythrocytes incubated with 20xa0mM HCQ was not significantly reduced within 5xa0h in contrast to CQ did. Using HCQ coupled Sepharose chromatography (HCQ-Sepharose), we identified Band 3, spectrin, ankyrin, protein 4.1R and protein 4.2 as HCQ binding proteins in human erythrocyte plasma membrane. Recombinant cytoplasmic N-terminal 43xa0kDa domain of Band 3 bound to HCQ-Sepharose and was eluted with 40xa0mM (but not 20xa0mM) HCQ. Band 3 transport activity was reduced by only 23% in the presence of 20xa0mM HCQ. Taken together, these data demonstrate that HCQ binds to the cytoplasmic N-terminal domain of Band 3 in human erythrocytes but does not inhibit dramatically its transport activity. We hypothesize that the trapping of HCQ on Band 3 contributes to the lower side effects of the drug on energy production in erythrocytes.