Mast cells derived from human induced pluripotent stem cells are useful for allergen tests

Background

Several methods have been developed to detect allergen-specific IgE in sera. The passive IgE sensitization assay using human IgE receptor-expressing rat cell line RBL-2H3 is a powerful tool to detect biologically active allergen-specific IgE in serum samples. However, one disadvantage is that RBL-2H3 cells are vulnerable to high concentrations of human sera. Only a few human cultured cell lines are easily applicable to the passive IgE sensitization assay. However, the use of human induced pluripotent stem cells (iPSCs) to generate human mast cells (MCs) has not yet been reported.

Identification of Cha o 3 homolog Cry j 4 from Cryptomeria japonica (Japanese cedar) pollen: Limitation of the present Japanese cedar–specific ASIT

Background

About one-third of the Japanese population suffers from Japanese cedar pollinosis, which is frequently accompanied by Japanese cypress pollinosis. Recently, a novel major Japanese cypress pollen allergen, Cha o 3, was discovered. However, whether a Cha o 3 homolog is present in Japanese cedar pollen remains to be determined.

Diagnostic criteria for acute‐onset type 1 diabetes mellitus (2012): Report of the Committee of Japan Diabetes Society on the Research of Fulminant and Acute‐onset Type 1 Diabetes Mellitus

Type 1 diabetes is a disease characterized by destruction of pancreatic β‐cells, which leads to absolute deficiency of insulin secretion. Depending on the manner of onset and progression, it is classified as fulminant, acute‐onset or slowly progressive type 1 diabetes. Here, we propose the diagnostic criteria for acute‐onset type 1 diabetes mellitus. Among the patients who develop ketosis or diabetic ketoacidosis within 3 months after the onset of hyperglycemic symptoms and require insulin treatment continuously after the diagnosis of diabetes, those with anti‐islet autoantibodies are diagnosed with ‘acute‐onset type 1 diabetes mellitus (autoimmune)’. In contrast, those whose endogenous insulin secretion is exhausted (fasting serum C‐peptide immunoreactivity <0.6 ng/mL) without verifiable anti‐islet autoantibodies are diagnosed simply with ‘acute‐onset type 1 diabetes mellitus’. Patients should be reevaluated after certain periods in case their statuses of anti‐islet autoantibodies and/or endogenous insulin secretory capacity are unknown.     

Japan College of Rheumatology guideline for the use of methotrexate in patients with rheumatoid arthritis

Methotrexate (MTX), the anchor drug in the current treatment strategy for rheumatoid arthritis (RA), was first approved for treatment of RA in Japan in 1999 at the recommended dose of 6–8?mg/week; it was approved as first-line drug with the maximum dose of 16?mg/week in February 2011. However, more than half of Japanese patients with RA are unable to tolerate a dose of 16?mg/week of MTX. Moreover, some serious adverse events during the treatment with MTX, such as pneumocystis pneumonia (PCP) and lymphoproliferative disorders (LPD) have been observed much more frequently in Japan than in other countries. Therefore, this article, an abridged English translation summarizing the 2016 update of the Japan College of Rheumatology (JCR) guideline for the use of MTX in Japanese patients with RA, is not intended to be valid for global use; however, it is helpful for the Japanese community of rheumatology and its understanding might be useful to the global community of rheumatology.     

Elevated BAFF levels in the cerebrospinal fluid of patients with neuro-Behçet's disease: BAFF is correlated with progressive dementia and psychosis

Neuro‐Behçet’s disease (NBD) is a serious complication of Behçet’s disease. Generally, NBD patients with a chronic course are refractory to immunosuppressive treatment, resulting in the deterioration of personality. In this study, levels of B cell‐activating factor belonging to the TNF family (BAFF) were measured in the cerebrospinal fluid (CSF) from 18 patients with NBD, 27 patients with epidemic aseptic meningitis (AM), 24 patients with multiple sclerosis (MS) and 34 healthy controls. BAFF levels in patients with NBD were significantly elevated compared with healthy controls, but showed no statistically significant elevation compared with either of the disease controls. In contrast, CSF IL‐6 levels were slightly elevated in patients with NBD and significantly elevated in patients with AM and MS compared with healthy controls. Patients with NBD were subdivided into two groups according to their clinical course (eight patients with a slowly progressive course presenting with psychosis and dementia and 10 patients with an acute course including aseptic meningitis, brainstem involvement and myelopathy). BAFF levels were significantly increased in those with a slowly progressive course compared with those with an acute course. CSF BAFF levels did not correlate with serum BAFF levels, CSF cell counts or CSF IL‐6 levels in patients with NBD. These data suggested that BAFF was produced within the central nervous system and may be associated with the development of NBD, particularly with a progressive course.     

Fate of full‐house immunofluorescence staining in renal allograft: A case report

Here, we report the case of a patient with renal allograft with full‐house immunofluorescence staining in the zero‐hour biopsy. Full‐house immunofluorescence staining is a well‐known characteristic of lupus nephritis. Previous studies have reported patients with full‐house immunofluorescence staining, but without other symptoms or serological findings; this condition is referred to as full‐house nephropathy. We identified only one case out of 2203 zero‐hour biopsies over 13 years. Zero‐hour biopsy presented no glomerular changes but showed full‐house immunofluorescence staining. Electron microscopy revealed a nonorganized electron‐dense deposit mainly in the mesangial lesion. Systemic lupus erythematosus (SLE)‐associated antibodies were negative, and complement deficiency was not observed in the donor patients. Deposition of immunoglobulin and complement levels markedly decreased within 1–3 years post transplantation. Neither donor nor recipient developed clinical or biological features of SLE; they showed good renal prognosis.     

Molecular anatomy of the β' subunit of the E. coli RNA polymerase: identification of regions involved in polymerase assembly

Background : The E. coli RNA polymerase is a multisubunit enzyme, which is present in two different forms: the catalytic competent core enzyme (α₂ββ ') and the promoter selective holoenzyme (α₂ββ 'σ). Correct assembly of individual subunits into core or holoenzyme is essential for the function of this enzyme.
Results : Mutant β ' proteins truncated near the centre or at the C-terminus were able to form stable core enzyme-like complexes under reconstitution conditions. Mutant β ' proteins lacking the region between amino acids 201–477 failed to form holoenzyme complexes while retaining the ability to form core enzyme complexes. Furthermore, free β ' subunit interacted with free σ subunit to form a stable β 'σ subassembly. Removal of amino acids 201–477 from the β ' subunit strongly interfered with this interaction.
Conclusion : Our results suggest that the N-terminal region of the β ' subunit is involved in the assembly of core enzyme. The region between amino acids 201 and 477 on β ' may be directly or indirectly involved in the interaction between the β ' subunit and the σ subunit.     

Heterogeneous reactivity of murine epidermal Langerhans cells after application of FITC: a histochemical evaluation

To elucidate the detailed kinetics of epidermal Langerhans cells after topical contact sensitizer stimulation, we examined ATPase or Ia positive epidermal cells of BALB/c mice in a time-spaced manner after the topical application of fluorescein isothiocyanate (FITC). We also performed double labeling of Langerhans cells in epidermal sheets with ATPase activity and Ia antigen or costimulatory molecules (B7-1 and B7-2) after the same stimulation. Observations showed that the density of ATPase positive cells and Ia positive cells decreased following a different time course; the former reached a nadir (77.4% of control) at 4 h but the latter reached a minimum (82.8% of control) at 16 h after the application of FITC. A double labeling technique revealed an increase in Ia single positive cells at 4 h as opposed to that of ATPase single positive cells at 16 h after application. Both costimulatory molecules were expressed on the dendritic processes of many Langerhans cells as a dotty pattern at 4 h after application; B7 positive and ATPase negative areas were observed at this time. On electron microscopic observation, a few activated Langerhans cells found in the dermis at 4 h after application had distinctive profiles compared with residual Langerhans cells in the epidermis. These findings suggest that there is a heterogeneity of reactivity to FITC in epidermal Langerhans cells, and that only a small portion of them migrates from the epidermis during sensitization. The findings also indicate the importance of the interaction between the Langerhans cell and its surrounding microenvironment in the epidermis for its activation. In addition, the results indicate that the enzymatic and the phenotypic markers do not definitively reflect the presence (or absence) of Langerhans cells.