A de novo dominant-negative variant is associated with OTULIN-related autoinflammatory syndrome.

OTULIN-related autoinflammatory syndrome (ORAS), a severe autoinflammatory disease, is caused by biallelic pathogenic variants of OTULIN, a linear ubiquitin-specific deubiquitinating enzyme. Loss of OTULIN attenuates linear ubiquitination by inhibiting the linear ubiquitin chain assembly complex (LUBAC). Here, we report a patient who harbors two rare heterozygous variants of OTULIN (p.P152L and p.R306Q). We demonstrated accumulation of linear ubiquitin chains upon TNF stimulation and augmented TNF-induced cell death in mesenchymal stem cells differentiated from patient-derived iPS cells, which confirms that the patient has ORAS. However, although the de novo p.R306Q variant exhibits attenuated deubiquitination activity without reducing the amount of OTULIN, the deubiquitination activity of the p.P152L variant inherited from the mother was equivalent to that of the wild-type. Patient-derived MSCs in which the p.P152L variant was replaced with wild-type also exhibited augmented TNF-induced cell death and accumulation of linear chains. The finding that ORAS can be caused by a dominant-negative p.R306Q variant of OTULIN furthers our understanding of disease pathogenesis.

Safety and efficacy of elapegademase in patients with adenosine deaminase deficiency: A multicenter, open-label, single-arm, phase 3, and postmarketing clinical study.

INTRODUCTION: Adenosine deaminase (ADA) deficiency is an ultrarare inherited purine metabolism disorder characterized by severe combined immunodeficiency. Elapegademase-lvlr is a new pegylated recombinant bovine ADA used in enzyme-replacement therapy (ERT) for ADA deficiency. Therefore, replacement with the new drug may eliminate the infectious risks associated with the currently used bovine intestinal-derived product, pegademase. METHODS: We conducted a multicenter, single-arm, open-label, phase 3, and postmarketing clinical study of elapegademase for patients with ADA deficiency. The following biochemical markers were monitored to determine an appropriate dose of elapegademase: the trough deoxyadenosine nucleotide (dAXP) level ≤0.02 µmol/mL in erythrocytes or whole blood and the trough serum ADA activity ≥1100 U/L (equivalent to plasma levels ≥15 µmol/h/mL) indicated sufficient enzyme activity and detoxification as efficacy endpoints and monitored adverse events during the study as safety endpoints. RESULTS: A total of four patients (aged 0-25 years) were enrolled. One infant patient died of pneumonia caused by cytomegalovirus infection whereas the other three completed the study and have been observed in the study period over 3 years. The infant patient had received elapegademase at 0.4 mg/kg/week until decease and the others received elapegademase at maximum doses of 0.3 mg/kg/week for 164-169 weeks. As a result, all four patients achieved undetectable levels of dAXPs together with sufficient enzyme activity, increased T and B cell numbers, and slightly elevated and maintained IgM and IgA immunoglobulin levels. Serious adverse events occurred in three patients, all of which were assessed as unrelated to elapegademase. CONCLUSIONS: This study showed that elapegademase had comparable safety and efficacy to pegademase as ERT for ADA deficiency by demonstrating stable maintenance of sufficient ADA activity and lowering dAXP to undetectable levels, while no drug-related adverse events were reported (Trial registration: JapicCTI-163204).

Changes in bone turnover markers after discontinuing long-term glucocorticoid administration in children with idiopathic nephrotic syndrome: a multicenter retrospective observational study.

BACKGROUND: Glucocorticoids affect bone turnover. Little is known about how bone turnover changes when glucocorticoids are discontinued following long-term administration. METHODS: This retrospective observational study was conducted on the relationship between discontinuation of long-term administration of glucocorticoid and bone turnover markers (BTMs) in patients with childhood-onset idiopathic nephrotic syndrome. Serum bone alkaline phosphatase (BAP), intact procollagen type 1 N-terminal propeptide (P1NP), and tartrate-resistant acid phosphatase-5b (TRACP-5b) were evaluated as BTMs. RESULTS: Thirty-eight pairs of BTMs at glucocorticoid administration and after discontinuation were analyzed in 29 patients. The median age at baseline was 12.4 (interquartile range, 9.0-14.5) years, and the median time from the onset of nephrotic syndrome was 5.9 (3.3-9.7) years. The mean period from prednisolone discontinuation to the measurement of BTMs after glucocorticoid discontinuation was 3.5 ± 1.0 months. Changes in BTMs after glucocorticoid discontinuation were modest when the daily prednisolone dose was < 0.25 mg/kg/day (ln BAP standard deviation [SD] score, p = 0.19; log intact P1NP SD score, p = 0.70; TRACP-5b, p = 0.95). When the daily prednisolone dose was ≥ 0.25 mg/kg/day, all BTMs increased significantly after glucocorticoid discontinuation (ln BAP SD score, p < 0.01; log intact P1NP SD score, p < 0.01; TRACP-5b, p < 0.01). CONCLUSIONS: Decreased BTMs can rise within a few months of discontinuing long-term glucocorticoid administration. When the administered glucocorticoid dose is low, changes in BTMs may be small. A higher resolution version of the Graphical abstract is available as Supplementary information.

Development of Graves' disease during drug-free remission of juvenile dermatomyositis.

We report a Japanese boy with Graves' disease (GD) which developed during drug-free remission of juvenile dermatomyositis (JDM). He had been diagnosed with JDM at the age of 6 years by typical skin rashes, muscle weakness, elevated serum transaminase levels, and typical findings of both magnetic resonance imaging and muscle biopsy. Although anti-melanoma differentiation antigen 5 autoantibody was positive, there was no complication of interstitial lung disease. He showed good response to methylprednisolone pulse therapy followed by oral prednisolone in combination with weekly methotrexate (MTX) and achieved drug-free remission after 3.5 years of treatment. Nevertheless, serum levels of soluble interleukin-2 receptor (sIL-2R) gradually elevated to 3185 U/ml despite no signs of relapse or malignancy. Hyperactivity and attention deficit was also noted. One year and 3 months after the cessation of MTX, he presented with abdominal pain, tachycardia, and apparent goitre. Laboratory tests showed elevated free triiodothyronine, undetectable thyroid stimulating hormone (TSH), and positive anti-TSH receptor antibodies. 99mTc scintigraphy showed high levels of thyroid uptake. He was diagnosed with GD and treated with 15 mg/day of thiamazole. Although transient drug eruption was observed, his thyroid functions are currently well-controlled on 5 mg/day of thiamazole. In conclusion, to our knowledge, this is the first report in English literature describing complication of GD with JDM. Unexpected elevation of sIL-2R could be a clue to the diagnosis of GD during the follow-up of JDM.

The effect of rituximab on the quality of life of children with refractory nephrotic syndrome.

BACKGROUND: Rituximab (RTX) is an effective treatment for maintaining remission in patients with nephrotic syndrome (NS), but there are few reports on the effect of RTX treatment on quality of life (QOL). The purpose of this study was to examine the effect of periodically repeated RTX treatment from the perspective of QOL. METHODS: We systematically assessed the QOL of pediatric patients with refractory NS and parents' perceptions of their children's QOL through a 2 year RTX treatment protocol. Pediatric patients from Hokkaido University Hospital with refractory NS who met our specific criteria were enrolled between January 2015 and December 2015. The RTX infusion was performed 4 times at 6-month intervals, followed by mizoribine administration with early discontinuation of calcineurin inhibitors. Quality of life scores were measured by the Pediatric Quality of Life Inventory version 4.0 (PedsQL) at each RTX administration and evaluated 2 years later. RESULTS: Twenty-two patients were analyzed. The patients' QOL and their parents' perceptions of their QOL improved over our 2 year treatment protocol. Nevertheless, the parents' scores were lower than the patients' scores on all scales, with slower improvement. CONCLUSIONS: Our treatment protocol showed a significant improvement of QOL in patients with refractory NS. Although the risk of the RTX treatment should be considered, the treatment is useful for patients with refractory NS.

Absent X-linked inhibitor of apoptosis protein expression in T cell blasts and causal mutations including non-coding deletion.

BACKGROUND: X-linked inhibitor of apoptosis protein (XIAP) deficiency is one of inborn errors of immunity characterized by recurrent hemophagocytic lymphohistiocytosis and refractory inflammatory bowel disease (IBD), mimicking Crohn's disease. The aim of this study is to make an accurate diagnosis of XIAP deficiency based on genetic and XIAP expression studies and to investigate endoscopic findings shared by patients with this disease. METHODS: Four male patients with recurrent hemophagocytic lymphohistiocytosis and long-term refractory IBD were studied for the diagnosis of XIAP deficiency. Endoscopic findings of the four patients were also studied in parallel. RESULTS: These four patients were diagnosed with XIAP deficiency based on the absent XIAP expression in cultured T-cell blasts. Sequence analysis of the responsible gene, XIAP, demonstrated two novel nonsense mutations of p.Gln114X and p.Glu25X, and a previously reported nonsense mutation of p.Arg381X. Although no mutations in the coding region were detected in the fourth patient, further studies demonstrated a novel 2,199 bp deletion encompassing non-coding exon 1, presumably affecting transcription and stability of XIAP mRNA. All of the patients eventually underwent hematopoietic stem cell transplantation, leading to a complete or partial remission of IBD. These four patients shared an endoscopic finding of multiple wide and longitudinal ulcers with straight and non-raised edge in the colon. CONCLUSIONS: X-linked inhibitor of apoptosis protein expression in T-cell blasts could facilitate the diagnosis of this disease, especially with causal mutations in non-coding regions.

Nonconditioned ADA-SCID gene therapy reveals ADA requirement in the hematopoietic system and clonal dominance of vector-marked clones.

Two patients with adenosine deaminase (ADA)-deficient severe combined immunodeficiency (ADA-SCID) received stem cell-based gene therapy (SCGT) using GCsapM-ADA retroviral vectors without preconditioning in 2003 and 2004. The first patient (Pt1) was treated at 4.7 years old, and the second patient (Pt2), who had previously received T cell gene therapy (TCGT), was treated at 13 years old. More than 10 years after SCGT, T cells showed a higher vector copy number (VCN) than other lineages. Moreover, the VCN increased with differentiation toward memory T and B cells. The distribution of vector-marked cells reflected variable levels of ADA requirements in hematopoietic subpopulations. Although neither patient developed leukemia, clonal expansion of SCGT-derived clones was observed in both patients. The use of retroviral vectors yielded clonal dominance of vector-marked clones, irrespective of the lack of leukemic changes. Vector integration sites common to all hematopoietic lineages suggested the engraftment of gene-marked progenitors in Pt1, who showed severe osteoblast (OB) insufficiency compared to Pt2, which might cause a reduction in the stem/progenitor cells in the bone marrow (BM). The impaired BM microenvironment due to metabolic abnormalities may create space for the engraftment of vector-marked cells in ADA-SCID, despite the lack of preconditioning.

Coexistence of acute poststreptococcal glomerulonephritis and acute rheumatic fever in a Japanese girl with primary Sjögren's syndrome.

Although acute poststreptococcal glomerulonephritis (APSGN) and acute rheumatic fever (ARF) are well-known complications of group A streptococcus infection, concomitant occurrence of both diseases is rare. We report an 11-year-old Japanese girl with primary Sjögren's syndrome complicated by acute renal failure about 2 weeks after the onset of pharyngitis. Although histopathological findings of the kidney were not confirmative, APSGN was suggested by the spontaneous recovery of her renal function, typical latent period with high levels of antistreptolysin O and low serum levels of C3 but not of C4. In addition, cardiac hypomotility and regurgitation of the 4 valves progressed in the convalescent phase of APSGN, which was accompanied by elevation of serum C-reactive protein and plasma brain natriuretic peptide (BNP) levels. Myocarditis was suggested by delayed gadolinium-enhancement of cardiac walls on cardiac magnetic resonance imaging. She was diagnosed with APSGN and ARF and was treated with a combination of short course prednisolone and prophylactic penicillin G. There is no relapse of renal or cardiac symptoms during 6 years follow-up. Unexpected elevation of plasma BNP in a convalescent stage of APSGN suggests the development of ARF. Underlying Sjögren's syndrome (SS) may modify the histopathological findings and make it difficult to differentiate APSGN from CTD-associated nephritis such as lupus nephritis (LN) even by renal biopsy.

Glucose metabolism disorders in children with refractory nephrotic syndrome.

BACKGROUND: Patients with refractory nephrotic syndrome (NS) are at high risk of medication-induced glucose metabolism disorders, because of their long-term use of diabetogenic medications, particularly glucocorticoids and calcineurin inhibitors (CNIs). However, there have been no comprehensive evaluations of glucose metabolism disorders in pediatric patients with refractory NS. Moreover, glucocorticoids and CNIs could not be discontinued in these patients until the effectiveness of rituximab on refractory NS was shown, and therefore, there has been limited opportunity to evaluate glucose metabolism disorders after discontinuation of these medications. METHODS: Consecutive pediatric patients who started rituximab treatment for refractory NS were enrolled. Their glucose metabolism conditions were evaluated using the oral glucose tolerance tests (OGTT) and HbA1c levels at the initiation of rituximab treatment. Patients with glucose metabolism disorders at the first evaluation were reevaluated after approximately 2 years. RESULTS: Overall, 57% (20/35) of study patients had glucose metabolism disorders, and 40% (8/20) of these patients were detected only by their 2-h OGTT blood glucose levels and not by their fasting blood glucose or HbA1c levels. Non-obese/non-overweight patients had significantly more glucose metabolism disorders than obese/overweight patients (p = 0.019). In addition, glucose metabolism disorders in 71% (10/14) of patients persisted after the discontinuation of glucocorticoids and CNIs. CONCLUSIONS: Whether the patient is obese/overweight or not, patients with refractory NS are at high risk of developing glucose metabolism disorders, even in childhood. Non-obese/non-overweight patients who are at high risk of diabetes need extra vigilance.

A deep intronic mutation of c.1166-285 T > G in SLC46A1 is shared by four unrelated Japanese patients with hereditary folate malabsorption (HFM).

Hereditary folate malabsorption (HFM) is an autosomal recessive disease caused by mutations in SLC46A1 encoding the proton-coupled folate transporter (PCFT). HFM patients present with various clinical features including megaloblastic anemia, thrombocytopenia, combined immunodeficiency and neurodevelopmental disorders. In this study, we report the same deep intronic mutation of c.1166-285 T > G shared by four unrelated Japanese patients with HFM. This mutation was shown to generate a cryptic splice donor site for a 168-bp insertion of intron 3 sequences, leading to premature termination in the middle of this insertion. This mutation could be a founder mutation in the Japanese population, but also could be a hot-spot and could be present in undiagnosed HFM patients worldwide because of the difficulty to detect this mutation.

Mesangial C4d deposition at diagnosis in childhood immunoglobulin A nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is a major cause of end-stage renal disease. Complement activation via the lectin pathway influences outcomes in IgAN. We examined the association of glomerular C4d deposition with clinicopathological severity at diagnosis and the disappearance of proteinuria in Japanese pediatric IgAN patients. METHODS: We retrospectively analyzed 25 children newly diagnosed with IgAN at Hokkaido University Hospital. We evaluated glomerular C4d immunofluorescent staining at diagnosis. We compared clinical findings, pathological findings (based on Oxford classification), and the disappearance of proteinuria within 24 months after renal biopsy between C4d-positive and C4d-negative patients. RESULTS: Glomerular C4d staining was observed in 14 patients (56.0%). C4d-positive patients had significantly higher proteinuria at diagnosis than C4d-negative patients (2.03 g/gCr vs 0.78 g/gCr; P = 0.005). The number of glomeruli with segmental glomerulosclerosis or adhesion (8.0% vs 0.0%; P = 0.046) and the extent of tubular atrophy/interstitial fibrosis (9.46% vs 2.86%; P = 0.031) were significantly increased in C4d-positive patients compared with C4d-negative patients. Further, the proportion of patients with modified T1 (>10%) was significantly higher in the C4d-positive group than the C4d-negative group. There was no significant difference, however, in the disappearance rate of proteinuria at 24 months after renal biopsy between groups (64% vs 82%; P = 0.149). CONCLUSIONS: Glomerular C4d deposition was associated with clinicopathological severity at diagnosis in Japanese pediatric patients with IgAN. Glomerular C4d deposition, however, was not a predictor of the disappearance of proteinuria within 24 months after diagnosis in Japanese pediatric patients with IgAN.

Efficacy of primary treatment with immunoglobulin plus ciclosporin for prevention of coronary artery abnormalities in patients with Kawasaki disease predicted to be at increased risk of non-response to intravenous immunoglobulin (KAICA): a randomised controlled, open-label, blinded-endpoints, phase 3 trial.

BACKGROUND: Genetic studies have indicated possible involvement of the upregulated calcium-nuclear factor of activated T cells pathway in the pathogenesis of Kawasaki disease. We aimed to assess safety and efficacy of ciclosporin, an immunosuppressant targeting this pathway, for protection of patients with Kawasaki disease against coronary artery abnormalities. METHODS: We did a randomised, open-label, blinded endpoints trial involving 22 hospitals in Japan between May 29, 2014, and Dec 27, 2016. Eligible patients predicted to be at higher risk for intravenous immunoglobulin (IVIG) resistance were randomly assigned to IVIG plus ciclosporin (5 mg/kg per day for 5 days; study treatment) or IVIG (conventional treatment) groups, stratified by risk score, age, and sex. The primary endpoint was incidence of coronary artery abnormalities using Japanese criteria during the 12-week trial, assessed in participants who received at least one dose of study drug and who visited the study institution at least once during treatment. This trial is registered to Center for Clinical Trials, Japan Medical Association, number JMA-IIA00174. FINDINGS: We enrolled 175 participants. One patient withdrew consent after enrolment and was excluded and one patient (in the study treatment group) was excluded from analysis because of lost echocardiography data. Incidence of coronary artery abnormalities was lower in the study treatment group than in the conventional treatment group (12 [14%] of 86 patients vs 27 [31%] of 87 patients; risk ratio 0·46; 95% CI 0·25-0·86; p=0·010). No difference was found in the incidence of adverse events between the groups (9% vs 7%; p=0·78). INTERPRETATION: Combined primary therapy with IVIG and ciclosporin was safe and effective for favourable coronary artery outcomes in Kawasaki disease patients who were predicted to be unresponsive to IVIG. FUNDING: Japan Agency for Medical Research and Development (grant CCT-B-2503).

CD44-Positive Glomerular Parietal Epithelial Cells in a Mouse Model of Calcineurin Inhibitors-Induced Nephrotoxicity.

BACKGROUND/AIMS: Calcineurin inhibitors (CNIs) such as cyclosporine A (CsA) and tacrolimus are immunosuppressants that are frequently used as "key drugs" in the fields of transplantation, steroid resistance, refractory nephrotic syndrome, and autoimmune disease. However, long-term CNI use causes nephrotoxicity, the features of which are arteriolar hyalinosis, tubular atrophy, striped interstitial fibrosis, and focal segmental glomerulosclerosis (FSGS). We investigated whether FSGS in CNI-induced nephrotoxicity is associated with CD44-positive glomerular parietal epithelial cells (PECs), which play a significant role in experimental and human FSGS pathogenesis. METHODS: We utilized the mouse model of CsA-induced nephrotoxicity, as well as controls. Histopathological and functional data were sequentially collected from 1 to 25 weeks after CsA injection. Glomerular expression of CD44 was immunohistochemically evaluated, as were markers for glomerular podocytes and PECs. RESULTS: Glomerular CD44 expression occurred from 2 weeks after CsA injection and gradually increased in the CsA group. CD44-positive glomerular cells showed coexpression of claudin-1 (PEC marker) but not of synaptopodin (podocyte marker). From 20 weeks after CsA injection, the cells formed a bridge between Bowman's capsule and the capillary tuft. These features are compatible with those of activated PECs, in which increased foot process effacement leads to bridge formation, and subsequently to an increase in glomerulosclerosis and a decrease in the expression of podocyte markers from 20 weeks. CONCLUSION: CD44-positive (activated) PECs reflect extremely early podocyte injury in the progression of FSGS formation and may be a good marker for early detection of CNI-induced nephrotoxicity.

Persistent systemic rotavirus vaccine infection in a child with X-linked severe combined immunodeficiency.

OBJECTIVE: The main aims of the present study were to elucidate the systemic group A rotavirus (RVA) infection and to clarify the genetic changes of persistent virus in the X-linked severe combined immunodeficiency (SCID) patient. METHODS: RotaTeq vaccine (RV5) genotype-specific real-time reverse transcription polymerase chain reaction was used to monitor viral RNA load in serially collected serum and stool samples. Next-generation sequence analysis was used to determine the genotype of the virus by sequencing 11 gene segments. Polyacrylamide gel electrophoresis (PAGE) analysis was used to identify rearrangement of viral genes. The gene rearrangement was examined in NSP5 gene by using Sanger sequence. RESULTS: A 7-month-old boy demonstrated chronic diarrhea following the third administration of RV5 and failure to thrive. He was diagnosed with X-linked SCID and successfully underwent cord blood transplantation. High copy numbers of RV5 genotype G1 RNA were detected in serially collected stool and serum samples and the kinetics of viral RNA loads were correlated with the degree of clinical disease. Next-generation sequence analysis revealed genetic reassortment at least between the strains WI79-9/G1P7[5] and WI79-4/G6P1A[8] in the VP7 gene and the VP4 gene among the vaccine-derived rotavirus strains. In addition, PAGE analysis suggested genetic rearrangements in several genes, and it was confirmed in the NSP5 gene by sequence analysis. CONCLUSIONS: The kinetics of RVA RNA load in serum and stool samples was consistent with the clinical course of the patient. Among five genotypes of RV5 vaccine, G1 genotype replicated well in this patient. Reassortment and rearrangements were demonstrated in persistently infected G1 genotype of RV5.

Evaluation of systemic activity of pediatric primary Sjögren's syndrome by EULAR Sjögren's syndrome disease activity index (ESSDAI).

OBJECTIVES: The purpose of this study is to evaluate systemic disease activity of pediatric Sjögren's syndrome (SS) using European League Against Rheumatism (EULAR) Sjögren's syndrome disease activity index (ESSDAI). METHODS: We retrospectively reviewed medical records of patients with SS who have been diagnosed according to 1999 Japanese diagnostic criteria for SS before 16 years old at KKR Sapporo Medical Center, Hokkaido University Hospital, and affiliated hospitals. We analyzed clinical and laboratory data and calculated ESSDAI at both diagnosis and peak activity. RESULTS: Twenty-five patients (2 boys and 23 girls) were enrolled. Only 4 patients had sicca symptoms at diagnosis. Mean ESSDAI scores at diagnosis and peak activity were 12.68 (2-31) and 15.08 (2-38), respectively. Only 3 patients were inactive (ESSDAI score <5) at diagnosis. Frequently involved domains at diagnosis were the biological (96%) followed by the constitutional (68%), glandular (44%), articular (44%), cutaneous domains (28%), renal (16%), and central nervous system (12%). At peak activity, biological domain (96%) was followed by the constitutional (72%), glandular (60%), articular (44%), cutaneous (28%), central nervous system (20%), and renal domains (16%). CONCLUSION: Pediatric SS is suspected from active systemic manifestations. The items of ESSDAI are useful clues to the diagnosis of pediatric SS.

Myositis-specific autoantibodies in Japanese patients with juvenile idiopathic inflammatory myopathies.

OBJECTIVES: The aim of our study is to clarify the association of myositis-specific autoantibodies (MSAs) with clinical and laboratory features in Japanese patients with juvenile idiopathic inflammatory myopathies (JIIMs). METHODS: We retrospectively analyzed the frequency of MSAs and their association with clinical or laboratory findings in 25 Japanese patients with JIIMs in Hokkaido district. RESULTS: Eighteen of the 25 patients (72%) were positive for MSAs; seven with anti-melanoma differentiation associated gene (MDA) 5 (28%), five with anti-transcriptional intermediary factor (TIF)-1γ (20%), four with anti-MJ/nuclear matrix protein (NXP)-2 (16%), two with anti-Jo-1 (8%), one with anti- HMG-CoA reductase, one with anti-signal recognition peptide (SRP) antibodies (4% each), including co-existence and transition of MSAs in one patient each. Anti-MDA5 antibodies were related to interstitial lung disease (ILD) and arthritis but not to amyopathic juvenile dermatomyositis. Drug-free remission was achieved, once ILD was overcome in this group. Anti-TIF-1γ antibodies were associated with typical rashes and mild myositis. Anti-MJ/NXP2 and anti-SRP antibodies were associated with severe muscle weakness. No patient was complicated with malignancy. CONCLUSION: Anti-MDA5 antibodies are prevalent and closely associated with ILD in our series compared with other countries. There was no apparent difference in clinical features associated with other MSAs among races.

Germline mosaicism is a pitfall in the diagnosis of "sporadic" X-linked Alport syndrome.

Approximately 80% of patients with Alport syndrome have X-linked Alport syndrome (XLAS), which is caused by mutations in the type IV collagen alpha 5 gene (COL4A5). In patients with XLAS, approximately 10-15% of COL4A5 mutations occur as spontaneous events. Here, we describe maternal germline mosaicism in a family of XLAS patients. Since our patient's parents showed normal urinary findings without COL4A5 mutation using genomic DNA isolated from peripheral leukocytes, the patient was initially diagnosed with "sporadic" XLAS. However, genetic analysis of the patient's sister with microscopic hematuria identified the same COL4A5 heterozygous mutation. Therefore, we concluded that our patient and the sister had XLAS caused by maternal germline mosaicism, not "sporadic" XLAS. Our case suggests that "sporadic" XLAS may in some patients be caused by the transmission of an abnormal allele from either parent with germline mosaicism in COL4A5. Germline mosaicism is thought to be rare, but we should consider that even asymptomatic parents of "sporadic" XLAS patients could carry a somatic and/or germline mosaicism. More cautious genetic counseling is advisable for all "sporadic" XLAS patients. Furthermore, urinalysis screening of "sporadic" XLAS patients' siblings is also important to enable an earlier detection of parental germline mosaicism.

Periodically repeated rituximab administrations in children with refractory nephrotic syndrome: 2-year multicenter observational study.

BACKGROUND: Rituximab (RTX) is effective in maintaining remission in patients with nephrotic syndrome (NS), but a standard protocol of RTX administration has not been established. METHODS: This study was a 2-year multicenter observational study, in which consistent treatments and evaluations were performed. We enrolled pediatric patients with refractory NS between January 2015 and December 2015. RTX infusion was performed four times at 6-month intervals, followed by mizoribine pulse therapy with early discontinuation of calcineurin inhibitor (CNI). Primary endpoints were the relapse-free survival rate and the number of relapses after RTX administration. Secondary endpoints were changes in side effects associated with long-term steroid administration. RESULTS: Twenty-two patients were analyzed. The relapse-free survival rate at 1 year and 2 years was 50 and 46%, respectively. Twenty-one patients accomplished our protocol and the frequency of relapse was reduced under the discontinuation of CNI. Although two patients were diagnosed with frequent relapse and/or steroid dependency during the observation period, the frequency of relapse decreased with each rituximab dose. Statistically significant improvements in all steroid complications were observed in the final examination, but no significant improvements were observed from 1 to 2 years after RTX administration. One patient had agranulocytosis, and three patients showed electrocardiographic abnormalities. CONCLUSIONS: Our protocol was useful and safe for refractory NS. However, RTX administration four times might have been excessive in patients who had no relapse by 1 year after the initial RTX administration. Further investigation of the most appropriate method of RTX administration is required.

Pair analysis and custom array CGH can detect a small copy number variation in COQ6 gene.

BACKGROUND: Recently, comprehensive genetic approaches for steroid-resistant nephrotic syndrome (SRNS) using next-generation sequencing (NGS) have been established, but causative gene mutations could not be detected in almost 70% of SRNS patients. Main reason for the low variant detection rate is that most of them are SRNS caused not by genetic but by immunological factors. But some of them are probably because of the difficulty of detecting copy number variations (CNVs) in causative genes by NGS. METHODS: In this study, we performed two analytical methods of NGS data-dependent pair analysis and custom array comparative genomic hybridization (aCGH) in addition to NGS analysis in an infantile nephrotic syndrome case. RESULTS: We detected only one known pathogenic heterozygous missense mutation in exon 7 of COQ6 c.782C > T, p.(Pro261Leu) by NGS. With pair analysis, heterozygous exon 1-2 deletion was suspected and was confirmed by custom aCGH. As a result, a small CNV was successfully detected in the COQ6 gene. Because we could detect variants in COQ6 and could start treatment by coenzyme Q10 (CoQ10) in his very early stage of SRNS, the patient achieved complete remission. CONCLUSIONS: These relatively novel methods should be adopted in cases with negative results in gene tests by NGS analysis. Especially, in cases with CoQ10 deficiency, it is possible to delay initiating dialysis by starting treatment at their early stages.

Evaluation of a Novel Immunochromatographic Assay for Detection of Human Adenoviruses from Throat Swab Samples Compared with Real-time PCR.

BACKGROUND: The aim of this study was to determine the sensitivity and specificity of a novel immunochromatographic assay (ICA) kit, ALSONIC® Adeno (Alfresa Pharma Co., Osaka, Japan), for the detection of human adenovirus (HAdV) from throat swab samples based on the results of real-time PCR. The incubation time required for the novel assay kit (5 minutes) is shorter than that required for other ICA kits that are available in Japan. METHODS: Throat swab samples were taken from 151 patients aged 6 months to 15 years who were suspected of having respiratory tract infections caused by HAdV. RESULTS: The sensitivity and specificity of the ICA for detection of HAdV were 92.2% (83/90) and 95.1% (58/61), respectively, and the assay showed positive and negative predictive values of 96.5% (83/86) and 89.2% (58/65), respectively. CONCLUSIONS: ALSONIC® Adeno is suitable as a diagnostic tool in the acute phase of HAdV infection.