Modelling urea-cycle disorder citrullinemia type 1 with disease-specific iPSCs.

Citrullinemia type 1 (CTLN1) is a urea cycle disorder (UCD) caused by mutations of the ASS1 gene, which is responsible for production of the enzyme argininosuccinate synthetase (ASS), and classically presented as life-threatening hyperammonemia in newborns. Therapeutic options are limited, and neurological sequelae may persist. To understand the pathophysiology and find novel treatments, induced pluripotent stem cells (iPSCs) were generated from a CTLN1 patient and differentiated into hepatocyte-like cells (HLCs). CTLN1-HLCs have lower ureagenesis, recapitulating part of the patient's phenotype. l-arginine, an amino acid clinically used for UCD treatment, improved this phenotype in vitro. Metabolome analysis revealed an increase in tricarboxylic acid (TCA) cycle metabolites in CTLN1, suggesting a connection between CTLN1 and the TCA cycle. This CTLN1-iPSC model improves the understanding of CTLN1 pathophysiology and can be used to pursue new therapeutic approaches.

Timing of Haemophilus influenzae type b vaccination after cardiac surgery.

BACKGROUND: The best time for vaccination in infants with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) surgery is unclear, but it is important to prevent Haemophilus influenzae type b (Hib) infection in infants with CHD after CPB surgery. To identify the best time for Hib vaccination in infants with CHD after CPB surgery, we investigated the immunological status, and the efficacy and safety of Hib vaccination after CPB surgery. METHODS: Sixteen subjects who underwent surgical correction of ventricular septal defect with CPB were investigated. Immunological status and cytokines were analyzed before surgery, 2 months after surgery, and before Hib booster vaccination. Hib-specific IgG was also measured to evaluate the effectiveness of vaccination. RESULTS: Immunological status before and 2 months after surgery (e.g. whole blood cells and lymphocyte subset profile) was within the normal range and no subjects had hypercytokinemia. Additionally, all subjects who received Hib vaccination at 2-3 months after CPB surgery had effective serum Hib-specific IgG level for protection against Hib infection without any side-effects. CONCLUSIONS: CPB surgery does not influence acquired immunity and Hib vaccination may be immunologically safe to perform at 2 months after CPB surgery. Hib vaccination at 2-3 months after CPB surgery was effective in achieving immunization for infants with simple left-right shunt-type CHD.

Transcriptional regulation by infliximab therapy in Kawasaki disease patients with immunoglobulin resistance.

BACKGROUND: Infliximab (IFX), a known monoclonal antibody against tumor necrosis factor-α (TNF-α), is used to treat Kawasaki disease (KD) patients with intravenous immunoglobulin (IVIG) resistance. The transcriptional modulation of inflammation following IFX therapy has not been reported in KD patients. METHODS: We investigated the transcript abundance profiles in whole blood obtained from eight IVIG-resistant KD subjects treated with IFX therapy using microarray platforms and compared them with those in initially IVIG-responsive subjects. A pathway analysis was performed using WikiPathways to search for the biological pathways of the transcript profiles. Four transcripts changed by IFX therapy were subsequently validated using quantitative real-time polymerase chain reaction. RESULTS: The pathway analysis showed the reduced abundance of transcripts in the nucleotide-binding oligomerization domain, matrix metalloproteinase (MMP), and inflammatory cytokine pathways and the increased abundance of transcripts in the T-cell receptor, apoptosis, TGF-ß, and interleukin-2 pathways. Additionally, the levels of four transcripts (peptidase inhibitor-3, MMP-8, chemokine receptor-2, and pentraxin-3) related to KD vasculitis and IVIG resistance decreased after IFX therapy. CONCLUSION: The administration of IFX was associated with both the signaling pathways of KD inflammation and several transcripts related to IVIG resistance factors. These findings provide strong theoretical support for the use of IFX in KD patients with IVIG resistance.

Clinical score and transcript abundance patterns identify Kawasaki disease patients who may benefit from addition of methylprednisolone.

Intravenous immunoglobulin (IVIG) treatment-resistant patients are high risk of developing coronary artery lesions with Kawasaki disease. The IVIG-responsive (Group A; n = 6) and IVIG-resistant patients (Group B) were predicted before starting the initial treatment using the Egami scoring system and randomly allocated as a single-IVIG treatment group (group B1; n = 6) or as a IVIG-plus-methylprednisolone (IVMP) combined therapy group (group B2; n = 5). We investigated the transcript abundance in the leukocytes of those patients using a microarray analysis. Five patients in group A and one patient in group B1 responded to initial IVIG treatment. All group B2 patients responded to IVIG-plus-IVMP combined therapy. Before performing these treatments, those transcripts related to IVIG resistance and to the development of coronary artery lesions, such as IL1R, IL18R, oncostatin M, suppressor of cytokine signaling-3, S100A12 protein, carcinoembryonic antigen-related cell adhesion molecule-1, matrix metallopeptidase-9, and polycythemia rubra vera-1, were more abundant in group B patients in comparison with group A patients. Moreover, those transcripts in group B2 patients were more profoundly and broadly suppressed than group B1 patients after treatment. This study elucidated the molecular mechanism of the effectiveness of IVIG-plus-IVMP combined therapy.

Slowly progressing form of type 1 diabetes mellitus in children: genetic analysis compared with other forms of diabetes mellitus in Japanese children.

AIMS: Slowly progressing insulin-dependent diabetes mellitus (SPIDDM, hereafter referred to as IDDMS in this article) is a unique subtype of type 1 diabetes in Japanese children. To clarify the genetic background of IDDMS, we analyzed HLA-DRB1, -DQB1 and -DQA1 alleles, phenotypes, and genotypes and compared them with acute-onset type 1 diabetes, non-insulin-dependent diabetes mellitus (NIDDM), and control subjects. METHODS: HLA-DRB1, -DQA1, and -DQB1 types were defined by DNA analysis using polymerase chain reaction (PCR), and typing for human leukocyte antigen (HLA) was performed by the sequencing-based typing (SBT) method using Match Maker and MT Navigator in combination. HLA-A24 was determined by the PCR-sequence-specific oligo-nucleotide probe (PCR-SSOP) method. The 234 patients with type 1 diabetes were divided into three groups: 32 cases of IDDMS, 137 cases of acute-onset form aged more than 5 yr (IDDMA), and 65 cases of acute-onset form less than 5 yr of age at onset (IDDME). In addition, we studied 55 children with type 2 diabetes (NIDDM) and 97 normal controls. RESULTS: The patients with IDDMS were older at diagnosis and had a greater body mass index (BMI) than those with IDDM (A + E). The prevalence of islet autoantbodies was not significantly different from IDDMA. The allele frequencies of DRB1*0405, DQA1*0302, and DQB1*0401 were significantly increased; however, DRB1*0901, DQA1*03, DQB1*0303, and HLA-A24 were low and not significantly different from control subjects. CONCLUSIONS: HLA phenotypes and genotypes in patients with IDDMS were different from those in NIDDM and control subjects and were closer to those of IDDMA. Together with a low prevalence of HLA-A24, the genetic features are similar to those of SPIDDM and latent autoimmune diabetes in adults (LADA) in adults. In our series, the clinical features such as lack of obesity and lack of responsiveness to oral hypoglycemic agents were most different from those of adults' onset.