Alport syndrome combined with lupus nephritis in a Chinese family: A case report

BACKGROUNDAlport syndrome (ATS) is a rare hereditary disease caused by mutations in genes such as COL4A3, COL4A4, and COL4A5. ATS involves a spectrum of phenotypes ranging from isolated hematuria that is nonprogressive to progressive renal disease with extrarenal abnormalities. Although ATS can be combined with other diseases or syndromes, ATS combined with lupus nephritis has not been reported before.CASE SUMMARYA Chinese family with ATS was recruited for the current study. Clinical characteristics (including findings from renal biopsy) of ATS patients were collected from medical records, and potential causative genes were explored by whole-exome sequencing. A heterozygous substitution in intron 22 of COL4A3 ({"type":"entrez-nucleotide","attrs":{"text":"NM_000091","term_id":"1732746140","term_text":"NM_000091"}}NM_000091 c.2657-1G>A) was found in the patients, which was further confirmed by quantitative polymerase chain reaction.CONCLUSIONHeterozygous substitution of a COL4A3 gene splice site was identified by whole-exome sequencing, revealing the molecular pathogenic basis of this disorder. In general, identification of pathogenic genes can help to fully understand the molecular mechanism of disease and facilitate precise treatment.     

A novel frameshift mutation of COL4A5 in a Chinese family with presumed IgA nephropathy and chronic glomerulonephritis

BackgroundAlport syndrome (ATS) is a hereditary nephritis with hereditary and clinical heterogeneity; the early clinical symptoms are atypical, which can easily lead to misdiagnosis. The proband, a 6‐year‐old girl, was found to have microscopic hematuria, proteinuria, and visual impairment at about 5 years old; the results of renal pathological examination revealed mesangial hyperplasia and IgA deposition. The proband''s father exhibited gross hematuria, eye swelling, and bilateral hearing loss after the age of 5, renal function progressively decreased, and he underwent right renal allograft at the age of 23 due to renal failure. The proband and her father were clinically diagnosed as IgA nephropathy and chronic glomerulonephritis, respectively.MethodsFor proband, targeted exome capture sequencing was performed using the Targeted Exome Capture Kit; this kit targets 162 genes known to cause renal diseases. The identified mutation was confirmed and analyzed for cosegregation by Sanger sequencing in other family members whose gDNA was available.ResultsTargeted exome capture sequencing revealed a novel heterozygous variant ({"type":"entrez-nucleotide","attrs":{"text":"NM_000495","term_id":"1677473130","term_text":"NM_000495"}}NM_000495, c.697delG, p.G233fs) in the COL4A5 gene of the proband; the variant was inherited from her father. The variant was likely pathogenic according to the criteria of the American College of Medical Genetics and Genomics.ConclusionIn this study, we first report a c.697delG mutation of COL4A5 in two patients presumed IgA nephropathy and chronic glomerulonephritis. This study emphasizes on the diagnostic value of next‐generation sequencing for hereditary kidney diseases to help in their timely and cost‐effective diagnosis, determine appropriate treatments, and promote genetic counseling.     

Neurodegenerative disorder and diffuse brain calcifications due to FARSB mutation in two siblings

Pathogenic mutations in the FARSB gene are associated with neurodevelopmental disorder involving the brain, liver, and lungs. We report genetic analysis of a family including two affected members with this disorder, which revealed a homozygous pathogenic missense variant, FARSB: {"type":"entrez-nucleotide","attrs":{"text":"NM_005687.4","term_id":"743405629","term_text":"NM_005687.4"}}NM_005687.4:c.853G > A:p.E285K in both affected patients. The parents were heterozygous for this variant.     

Christianson syndrome: A novel splicing variant of SLC9A6 causes exon skipping in a Chinese boy and a literature review

BackgroundVariants in the endosomal solute carrier family 9 member A6 (SLC9A6)/(Na⁺,K⁺)/H⁺ exchanger 6 (NHE6) gene have been linked to epilepsy, speech loss, truncal ataxia, hyperkinesia, and postnatal microcephaly.MethodsIn the present study, we evaluated genetic alterations in a 3‐year‐old Chinese boy displayed features of epilepsy, psychomotor retardation, microcephaly, low body weight, difficulty in feeding, excessive movement, attention loss, ataxia, and cerebellar atrophy and his healthy family using WES method. The identified variant was further confirmed by Sanger sequencing method. Finally, minigene assays were used to verify whether the novel SLC9A6 intronic variant influenced the normal splicing of mRNA.ResultsWe identified a novel hemizygous splicing variant [{"type":"entrez-nucleotide","attrs":{"text":"NM_001042537.1","term_id":"110227625","term_text":"NM_001042537.1"}}NM_001042537.1: c.1463‐1G>A] in SLC9A6 by trio‐based exome sequencing. The minigene expression in vitro confirmed the splicing variant altered a consensus splice acceptor site of SLC9A6 intron 11, resulting in skipping over exon 12.ConclusionsOur finding extends the catalog of pathogenic intronic variants affecting SLC9A6 pre‐mRNA splicing and provides a basis for the genetic diagnosis of CS.     

Novel splicing‐site mutation in DCAF17 gene causing Woodhouse‐Sakati syndrome in a large consanguineous family

BackgroundWoodhouse‐Sakati syndrome is a rare autosomal recessive disease with endocrine and neuroectodermal aberrations with heterogeneous phenotypes and disease course. The most common phenotypes of the disease are progressive sensorineural hearing loss and alopecia, mild‐to‐moderate mental retardation and hypogonadism. The disease results from mutations in the DCAF17 gene.MethodHere, we reported a large consanguineous pedigree with multiple affected individuals with Woodhouse‐Sakati syndrome phenotypes. Laboratory tests confirmed the endocrine perturbance in affected individuals. To find out the underlying genetic change, whole‐exome sequencing was carried out.ResultAnalysis of the exome data identified a splicing‐site deletion {"type":"entrez-nucleotide","attrs":{"text":"NM_025000.3","term_id":"259906387","term_text":"NM_025000.3"}}NM_025000.3:c.1423‐1_1425delGACA in DCAF17 gene. Sanger sequencing confirmed the co‐segregation of the variant with the disease phenotypes in the family.ConclusionThe variant is predicted to cause aberrant splicing, i.e., exon skipping, resulting in the translation of a truncated functionless protein which results in appearance of typical phenotypic features and clinical laboratory findings of Woodhouse‐Sakati syndrome in affected members of the family.     

Missense mutation in DYNC1H1 gene caused psychomotor developmental delay and muscle weakness: A case report

BACKGROUNDThe DYNC1H1 gene encodes a part of the dynamic protein, and the protein mutations may further affect the growth and development of neurons, resulting in degeneration of anterior horn cells of the spinal cord, and a variety of clinical phenotypes finally resulting in axonal Charcot-Marie-Tooth disease type 20 (CMT20), mental retardation 13 (MRD13) and spinal muscular atrophy with lower extremity predominant 1 (SMA-LED). The incidence of the disease is low, and it is difficult to diagnose, especially in children. Here, we report a case of DYNC1H1 gene mutation and review the related literature to improve the pediatrician’s understanding of DYNC1H1 gene-related disease to make an early correct diagnosis and provide better services for children.CASE SUMMARYA 4-mo-old Chinese female child with adducted thumbs, high arch feet, and epileptic seizure presented slow response, delayed development, and low limb muscle strength. Electroencephalogram showed abnormal waves, a large number of multifocal sharp waves, sharp slow waves, and multiple spasms with a series of attacks. High-throughput sequencing and Sanger sequencing identified a heterozygous mutation, c.5885G>A (p.R1962H), in the DYNC1H1 gene ({"type":"entrez-nucleotide","attrs":{"text":"NM_001376","term_id":"1519312342"}}NM_001376) of the proband, which was not identified in her parents. Combined with the clinical manifestations and pedigree of this family, this mutation is likely pathogenic based on the American Academy of Medical Genetics and Genomics guidelines. The child was followed when she was 1 year and 2 mo old. The magnetic resonance imaging result was consistent with the findings of white matter myelinated dysplasia and congenital giant gyrus. The extensive neurogenic damage to the extremities was considered, as the results of electromyography showed that the motor conduction velocity and sensory conduction of the nerves of the extremities were not abnormal, and the degree of fit of the children with severe contraction was poor. At present, the child is 80 cm in length and 9 kg in weight, with slender limbs and low muscle strength, and still does not raise her head. She cannot sit or speak. Speech, motor, and mental development was significantly delayed. There is still no effective treatment for this disease.CONCLUSIONWe herein report a de novo variant of DYNC1H1 gene, c.5885G>A (p.R1962H), leading to overlapping phenotypes (seizure, general growth retardation, and muscle weakness) of CMT20, MRD13, and SMA-LED, but there is no effective treatment for such condition. Our case enriches the DYNC1H1 gene mutation spectrum and provides an important basis for clinical diagnosis and treatment and genetic counseling.     

Novel insertion mutation in the PLA2G6 gene in an Iranian family with infantile neuroaxonal dystrophy

BackgroundInfantile neuroaxonal dystrophy is an autosomal recessive neurological disorder. Individuals with infantile neuroaxonal dystrophy experience progressive loss of vision, mental skills and muscular control, and other variable clinical signs. Pathogenic variants in the PLA2G6 gene, encoding phospholipase A2, are recognized to be the fundamental reason for infantile neuroaxonal dystrophy. This study aimed to detect pathogenic variant in a consanguine Iranian family with infantile neuroaxonal dystrophy.MethodsThe mutation screening was done by whole exome sequencing followed by direct Sanger sequencing.ResultsWe identified a homozygous insertion mutation, {"type":"entrez-nucleotide","attrs":{"text":"NM_003560","term_id":"1653962520"}}NM_003560: c.1548_1549insCG (p.G517Rfs*29) in exon 10 of PLA2G6 in the patient. The parents were heterozygous for variant.ConclusionsBecause of the clinical heterogeneity and rarity of infantile neuroaxonal dystrophy, whole exome sequencing is critical to confirm the diagnosis and is an excellent tool for INAD management.     

Application of Blood Group Genotyping by Next-Generation Sequencing in Various Immunohaematology Cases

BackgroundNext-generation sequencing (NGS) technology has been recently introduced into blood group genotyping; however, there are few studies using NGS-based blood group genotyping in real-world clinical settings. In this study, we applied NGS-based blood group genotyping into various immunohaematology cases encountered in routine clinical practice.MethodsThis study included 4 immunohaematology cases: ABO subgroup, ABO chimerism, antibody to a high-frequency antigen (HFA), and anti-CD47 interference. We designed a hybridization capture-based NGS panel targeting 39 blood group-related genes and applied it to the 4 cases.ResultsNGS analysis revealed a novel intronic variant ({"type":"entrez-nucleotide","attrs":{"text":"NM_020469.3","term_id":"1482586037","term_text":"NM_020469.3"}}NM_020469.3:c.29-10T>G) in a patient with an A_el phenotype and detected a small fraction of ABO*A1.02 (approximately 3–6%) coexisting with the major genotype ABO*B.01/O.01.02 in dizygotic twins. In addition, NGS analysis found a homozygous stop-gain variant ({"type":"entrez-nucleotide","attrs":{"text":"NM_004827.3","term_id":"1519311581","term_text":"NM_004827.3"}}NM_004827.3:c.376C>T, p.Gln126*; ABCG2*01N.01) in a patient with an antibody to an HFA; consequently, this patient''s phenotype was predicted as Jr(a−). Lastly, blood group phenotypes predicted by NGS were concordant with those determined by serology in 2 patients treated with anti-CD47 drugs.ConclusionNGS-based blood group genotyping can be used for identifying ABO subgroup alleles, low levels of blood group chimerism, and antibodies to HFAs. Furthermore, it can be applied to extended blood group antigen matching for patients treated with anti-CD47 drugs.     

Novel truncating variant in KMT2E associated with cerebellar hypoplasia and velopharyngeal dysfunction

KMT2E‐related neurodevelopmental disorder is a recently described intellectual disability syndrome often with speech difficulties. Here, we describe an individual with a heterozygous frameshift variant in KMT2E ({"type":"entrez-nucleotide","attrs":{"text":"NM_182931.2","term_id":"91199541","term_text":"NM_182931.2"}}NM_182931.2:c.2334_2337delTTAC, p.[Tyr779AlafsTer41]), intellectual disability, cerebellar hypoplasia, and velopharyngeal dysfunction. This case suggests potential mechanisms of speech disturbance in the disorder, requiring further investigation.     

Detection and Characterization of NF1 Microdeletions by Custom High Resolution Array CGH

In 5% to 10% of cases, neurofibromatosis type 1 is caused by microdeletions scattered across the entire NF1 gene and various neighboring genes. The phenotype appears to be more severe in patients with NF1 microdeletions than in patients with NF1 single point mutations. We have developed a new method for detecting and characterizing NF1 microdeletions based on a custom high-resolution oligonucleotide array comparative genomic hybridization by using the custom 8x15K Agilent array format. The array comprised a total of 14,207 oligonucleotide probes spanning the whole of chromosome 17, including 12,314 probes spanning an ∼8 Mb interval surrounding the NF1 locus. We validated this approach by testing NF1 microdeleted DNA samples previously characterized by means of microsatellites and real-time PCR methods. Our array comparative genomic hybridization provided enough information for subsequent long-range PCR and nucleotide sequencing of the microdeletion endpoints. Unlike previously described methods, our array comparative genomic hybridization was able to unambiguously differentiate between the three types of microdeletions (type I, type II, and atypical) and to characterize atypical microdeletions. Further comparative studies of patients with well-characterized genotypes and phenotypes and different microdeletions sizes and breakpoints will help determine whether haploinsufficiency of deleted genes and/or genes rearrangements influence clinical outcomes.Neurofibromatosis 1 (NF1, OMIM 162200) is an autosomal disorder with an estimated incidence of 1 in 3500 live births.¹ The main features of NF1 are multiple neurofibromas, café-au-lait spots, axillary freckling, Lisch nodules, tibial pseudarthrosis, and a predisposition to develop certain benign and malignant nervous system tumors.² NF1 is due to autosomal dominant loss-of-function mutations of the NF1 gene (neurofibromin 1; {"type":"entrez-nucleotide","attrs":{"text":"NM_000267","term_id":"270132515","term_text":"NM_000267"}}NM_000267).³ NF1 is located at 17q11.2 and contains 60 translated exons distributed over ∼300 kb.Most germline mutations identified so far in NF1 patients are intragenic single point mutations that cause truncation or loss of the encoded protein. However, in approximately 5% to 10% of cases, NF1 is caused by microdeletions scattered along the entire NF1 gene and neighboring genes.⁴ Most NF1 patients have one of two recurrent (typical) microdeletions.⁵ The type I microdeletion is 1.4 Mb long and is caused by non allelic homologous recombination between the NF1 proximal and distal low-copy repeats (NF1-REP-a and –c) flanking the NF1 gene.⁶ The type II microdeletion is smaller (1.2 Mb) and its breakpoints are located in the SUZ12 gene (suppressor of zeste 12 homolog; {"type":"entrez-nucleotide","attrs":{"text":"NM_015355","term_id":"1007388691","term_text":"NM_015355"}}NM_015355) and its pseudogene SUZ12P.^5,7 Less frequent than these two types of microdeletion are so-called atypical NF1 microdeletions with non-recurring breakpoints.⁸NF1 patients with microdeletions that encompass the entire NF1 coding region and various contiguous genes often have a more severe phenotype than patients with intragenic NF1 mutations—including dysmorphic features, learning disability, an excessive number and earlier onset of benign neurofibromas, developmental delay, and possibly a higher incidence of malignant peripheral nerve sheath tumors—supporting the existence of a contiguous gene syndrome.^8,9,10,11 However, the high phenotypic variability of the NF1 microdeletion syndrome, the small number of microdeletions so far characterized (for example fewer than 20 atypical NF1 microdeletions), and the imprecise definition of their boundaries make it difficult to establish reliable genotype/phenotype correlations.^8,10,12,13 To improve the identification of NF1 microdeletions, we developed a custom microarray and validated it by testing well-characterized NF1 microdeletions with typical/atypical microdeletions distinction using microsatellite markers and PCR-based gene dosage.     

Novel compound heterozygous mutations in a GNE myopathy with congenital thrombocytopenia: A case report and literature review

We reported a GNE myopathy with congenital thrombocytopenia on a young male patient. He presented with a 3‐year history of lower distal extremity weakness initially affecting his legs. The weakness slowly progressed to lower proximal legs and upper arms last 6 months. Whole‐exome sequencing revealed that the patient harbored two heterozygous gene mutations, including a novel insertion mutation c.*1037_*1038CACACACACACACACACACACA and c.C478T in exome 12 and 3 of the GNE gene ({"type":"entrez-nucleotide","attrs":{"text":"NM_001128227","term_id":"1677530972"}}NM_001128227), respectively. The levels of serum sialic acid in this patient were considerably decreased. Muscle MRI imaging showed the anterior and medial parts of his quadriceps were heavily affected by this disease. Hematoxylin and eosin staining showed prominent rimmed vacuoles with a lack of inflammatory response in the atrophied muscle. We also undertook a review of the current literature, searching for reports in which the GNE gene mutation caused the thrombocytopenia with or without muscle weakness. This new gene mutation finding broadens the GNE disease genotype spectrum, and further investigation of the relationship between GNE gene mutations and the heterogeneity of its clinical manifestations is needed.     

The distal arthrogryposis‐linked p.R63C variant promotes the stability and nuclear accumulation of TNNT3

BackgroundDistal arthrogryposis (DA) is comprised of a group of rare developmental disorders in muscle, characterized by multiple congenital contractures of the distal limbs. Fast skeletal muscle troponin‐T (TNNT3) protein is abundantly expressed in skeletal muscle and plays an important role in DA. Missense variants in TNNT3 are associated with DA, but few studies have fully clarified its pathogenic role.MethodsSanger sequencing was performed in three generation of a Chinese family with DA. To determine how the p.R63C variant contributed to DA, we identified a variant in TNNT3 ({"type":"entrez-nucleotide","attrs":{"text":"NM_006757.4","term_id":"1519315975"}}NM_006757.4): c.187C>T (p.R63C). And then we investigated the effects of the arginine to cysteine substitution on the distribution pattern and the half‐life of TNNT3 protein.ResultsThe protein levels of TNNT3 in affected family members were 0.8‐fold higher than that without the disorder. TNNT3 protein could be degraded by the ubiquitin‐proteasome complex, and the p.R63C variant did not change TNNT3 nuclear localization, but significantly prolonged its half‐life from 2.5 to 7 h, to promote its accumulation in the nucleus.ConclusionThe p.R63C variant increased the stability of TNNT3 and promoted nuclear accumulation, which suggested its role in DA.     

Hepatocyte nuclear factor 1B mutation in a Chinese family with renal cysts and diabetes syndrome: A case report

BACKGROUNDRenal cysts and diabetes (RCAD) syndrome is an autosomal dominant diabetic renal disease. Precise molecular diagnosis of RCAD syndrome has proven valuable for understanding its mechanism and personalized therapy.CASE SUMMARYA RCAD patient and her family were studied to investigate potential responsible genes by the whole exome sequencing (WES). Candidate pathogenic variants were validated by Sanger sequencing. The clinical characteristics of RCAD patient were collected from medical records. Unlike those typical RCAD patients, we observed renal manifestation and prediabetes phenotype, but not reproductive organ phenotype and hypomagnesaemia. A novel 7-bp deletion mutation in exon 4 of the hepatocyte nuclear factor 1B, {"type":"entrez-nucleotide","attrs":{"text":"NM_000458","term_id":"1519244814"}}NM_000458: c.882_888del (p.V294fs), was identified by WES and confirmed by Sanger sequencing. CONCLUSIONThis novel mutation identified in a Chinese family with RCAD syndrome might be the molecular pathogenic basis of this disorder.     

Sensitive Detection of KRAS Mutations in Archived Formalin-Fixed Paraffin-Embedded Tissue Using Mutant-Enriched PCR and Reverse-Hybridization

Recently, evidence has emerged indicating that assessment of KRAS mutations before anti-epidermal growth factor receptor therapy improves outcome in patients with metastatic colorectal cancer (CRC). We report here a novel reverse-hybridization (RH) assay to screen for KRAS mutations in formalin-fixed paraffin-embedded colorectal tissue samples. We combined mutant-enriched PCR based on peptide nucleic acid clamping and RH of amplification products to nitrocellulose test strips that contained a parallel array of oligonucleotide probes targeting 10 frequent mutations in codons 12 and 13 of the KRAS gene. DNA mixing experiments, which included eight different tumor cell lines with known KRAS mutations, were performed to examine the sensitivity of mutation detection. All KRAS mutations present in tumor cell lines were unambiguously identified by the RH assay with 1% of each cell line DNA diluted in normal DNA. RH was then used to screen for KRAS mutations in 74 colorectal tumor and 4 normal control samples. Twenty-six (35%) of the 74 tumor samples showed KRAS mutations. No mutation was found in the four samples of normal colorectal tissue. DNA sequencing without previous mutant enrichment, however, failed to detect four (15%) out of 26 KRAS-positive formalin-fixed paraffin-embedded samples (FFPE). This finding suggests that even after microdissection, mutant sequences in a given DNA isolate can be rare and more sensitive methods are needed for mutation analysis.The KRAS proto-oncogene (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog: Gene Bank Accession Number {"type":"entrez-nucleotide","attrs":{"text":"NM_033360","term_id":"575403058","term_text":"NM_033360"}}NM_033360) is one of the most prominent and most commonly mutated RAS family members in colorectal cancer (CRC). Oncogenic mutations of KRAS disrupt binding to GTP and allow it to remain in an active state.¹ The most common mutations in CRC and other cancer types affect codons 12 and 13, and to a lesser extend codon 61.^2,3,4 A link between the KRAS gene and an underlying epigenetic disorder in CRC was shown recently; KRAS mutations were associated with a subset of CRCs that exhibit methylation in multiple sets of genes and are referred to as CpG methylator phenotype. These tumors have distinct clinical, molecular and pathological features, and KRAS mutations in codon 12 and 13 were associated with so-called CpG methylator phenotype-low cases.^5,6 In another recent study, KRAS mutational status and methylation status were associated with decreased survival.⁷ The clinical implication of assessment of the KRAS mutation status in metastatic CRC was demonstrated very recently. The effect of antibody treatment of patients suffering from metastatic CRC with cetuximab was significantly enhanced as compared with standard chemotherapy alone when genomic DNA isolated from tumor tissue did not contain a KRAS mutation, whereas patients with KRAS mutations could not be shown to benefit from cetuximab treatment.⁸ Monoclonal antibodies such as cetuximab or panitumumab target the extracellular domain of the epidermal growth factor receptor thereby blocking ligand-induced epidermal growth factor receptor activation and subsequent signal transduction through pathways like the RAS/RAF/MAPK and P13/AKT cascades.^9,10 Results from recent randomized controlled trials suggest that patients with KRAS mutations in codons 12 and 13 do not benefit from these anti-epidermal growth factor receptor monoclonal antibody therapies,¹¹ and accurate treatment response prediction will spare the patient unnecessary treatment thereby focusing on more individualized therapy. Thus, reliable and sensitive determination of the KRAS mutation status becomes increasingly important in individual treatment decisions. Archival tissue of the primary tumor is easily accessible and is an important source for KRAS mutation testing. We developed a novel biomarker assay to detect KRAS mutations in archived formalin-fixed paraffin-embedded (FFPE) tissue. The test combines mutant-enriched PCR based on peptide nucleic acid clamping and reverse-hybridization (RH) to nitrocellulose test strips containing a parallel array of oligonucleotide probes targeting 10 mutations in codons 12 and 13 of the KRAS gene. Because mutations in codon 61 are extremely rare in CRC cases, these were not included in the assay.^2,3,4We then used the novel RH assay to screen for KRAS mutations in DNA extracted from FFPE tissue samples obtained from patients operated because of CRC.     

Vancomycin-loaded titanium coatings with an interconnected micro-patterned structure for prophylaxis of infections: an in vivo study

Titanium (Ti) and its alloys are widely applied as orthopedic implants for hip and knee prostheses, fixation, and dental implants. However, Ti and its alloys are bioinert and susceptible to bacteria and biofilm formation. Thus, surface biofunctionalisation of Ti is essential for improving the biofunction of Ti. The current in vitro study indicated that calcium phosphate bone cement with vancomycin doped on micro-patterned Ti with a grid-like structure surface could preserve the property of inhibition of bacterial adhesion and biofilm formation while not affecting the osteogenic differentiation. The present study investigated whether the biological performance of the bactericidal effect is preserved in vivo. The rabbit osteomyelitis model with tibial medullary cavity placement of Ti rods was employed to analyze the antibacterial effect of vancomycin-loaded Ti coatings with interconnected micro-patterned structure (TV). Thirty female rabbits (N = 10) were used to establish the implant-associated infection. Prior to implanting the T0 and TV rods into the medullary cavity of the left tibia of the rabbits, 10⁶ CFU mL⁻¹ methicillin-resistant Staphylococcus aureus (MRSA) was injected into the medullary cavity of the left tibia of the rabbits. The sterile Ti rod (NT) was used as the blank control. After 3 weeks, bone pathology was evaluated using X-ray and micro-CT. The in vivo study proposed that TV has the potential for prophylaxis against MRSA infection. Thus, the interconnected micro-patterned structured Ti rods loaded with vancomycin could be applied for preventing Ti implant-associated infections.

Vancomycin-loaded titanium coatings with an interconnected micro-patterned structure for prophylaxis of titanium implant associated infection.     

Evaluating Potential Disease‐Mediated Protein‐Drug Interactions in Patients With Moderate‐to‐Severe Plaque Psoriasis Receiving Subcutaneous Guselkumab

This open‐label, multicenter, phase I therapeutic protein‐drug interaction study was designed to evaluate the potential effect of guselkumab, a fully human anti‐interleukin‐23 immunoglobulin G1 lambda monoclonal antibody, on the pharmacokinetics of a cocktail of representative cytochrome P450 (CYP) probe substrates (midazolam (CYP3A4), S‐warfarin (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), and caffeine (CYP1A2)). Fourteen participants with psoriasis received a single subcutaneous dose of guselkumab 200 mg on day 8 and an oral probe cocktail on days 1, 15, and 36. Blood samples were collected for measuring plasma concentrations of these probe substrates on days 1, 15, and 36. No consistent trends in observed maximum plasma concentration and area under the curve from time 0 to infinity values of each probe CYP‐substrate before (day 1) and after guselkumab treatment (days 15 and 36) could be identified in each individual patient, suggesting that the use of guselkumab in patients with psoriasis is unlikely to influence the systemic exposure of drugs metabolized by CYP isozymes (CYP3A4, CYP2C9, CYP2C19, CYP2D6, and CYP1A2). The probe cocktail was generally well‐tolerated when administered in combination with guselkumab in patients with psoriasis.Clinicaltrials.gov Identifiers: {"type":"clinical-trial","attrs":{"text":"NCT02397382","term_id":"NCT02397382"}}NCT02397382.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

☑ Therapeutic proteins (TPs) that modulate cytokine concentrations and activity can indirectly influence expression of cytochrome P450 (CYP) isoenzymes and may alter CYP‐mediated metabolism of concomitantly administrated small molecule drugs. An in vitro study ¹ and two phase I studies ² , ³ were previously conducted to assess if interleukin (IL)‐23 modulates the expression or activity of multiple CYP isoenzymes (including CYP1A2, 2C9, 2C19, 2D6, and 3A4). These results suggest that potential TP‐drug interactions between guselkumab and drugs metabolized by CYP450 could be low.

• WHAT QUESTION DID THIS STUDY ADDRESS?

☑ This phase I study evaluated whether treatment with guselkumab, which selectively binds and inhibits IL‐23, affects CYP450 isoenzyme activity in patients with moderate‐to‐severe psoriasis.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

☑ Subcutaneous administration of guselkumab to patients with psoriasis has no effect on the pharmacokinetics (PK) of the evaluated CYP substrates.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

☑ These results suggest that guselkumab can be used for the treatment of psoriasis without significant PK interactions with drugs metabolized by CYP3A4, CYP2C9, CYP2C19, CYP2D6, or CYP1A2.

Psoriasis is a chronic inflammatory disease affecting 1–3% of the world’s population. ⁴ Traditional systemic therapies for psoriasis have not fully met patients’ needs. ⁵ Highly effective antibody‐based or fusion protein‐based biologics targeting key inflammatory mediators have been developed for psoriasis treatment. ⁶ Based on their mechanisms of action, biological psoriasis therapies can be classified as: (i) T‐cell modulating agents, (ii) tumor necrosis factor (TNF)‐α antagonists, (iii) interleukin (IL)‐12/23 and/or IL‐23 inhibitors, and (iv) IL‐17 inhibitors. ⁴ , ⁷ Guselkumab (Tremfya, Janssen Research & Development, Spring House, PA) is a fully human immunoglobulin G1 lambda (IgG1λ) monoclonal antibody (mAb) that selectively binds and inhibits IL‐23, a critical driver of pathogenic T cells in chronic plaque psoriasis. Clinical trials have demonstrated that guselkumab had favorable efficacy and safety profiles for the treatment of moderate‐to‐severe plaque psoriasis. ⁸ , ⁹ , ¹⁰ As a fully human IgG1λ mAb, guselkumab is expected to be metabolized in the same manner as any other endogenous IgG antibody (degraded into small peptides and amino acids via catabolic pathways) and subject to similar routes for elimination. ¹¹ Therefore, the likelihood of direct therapeutic protein (TP)‐drug interaction occurring during co‐administration of guselkumab and other concomitant small molecule medications is assumed to be low. In line with this, clinically relevant information has been published about potential TP‐drug interactions, ¹² , ¹³ , ¹⁴ , ¹⁵ , ¹⁶ and supports that mAbs do not elicit a direct effect on the metabolic/clearance pathways of small molecular therapeutics. However, the immunomodulatory properties of mAbs may indirectly alter the clearance of certain small molecules through noncatabolic hepatic metabolism pathways. ¹⁴ , ¹⁵ An in vitro study ¹ using cryopreserved human hepatocytes to assess whether IL‐12 and/or IL‐23 modulate the expression or activity of multiple cytochrome P450 (CYP) enzymes (i.e., CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) suggested that TP‐drug interactions between guselkumab and CYP450 substrates are unlikely. However, in vitro studies may have limitations in predicting clinical interactions between TPs and small molecule drugs. ¹⁷ To confirm these findings, we conducted a phase I study in patients with moderate‐to‐severe plaque psoriasis to determine if blocking IL‐23 with guselkumab for treatment of psoriasis would clinically alter the metabolism of probe substrates metabolized by CYP isozymes (CYP3A4, CYP2C9, CYP2C19, CYP2D6, or CYP1A2).     

Genetic variant in microRNA-146a gene is associated with risk of rheumatoid arthritis

ObjectiveTo investigated the association between single nucleotide polymorphisms (SNPs) in microRNA-146a (miR-146a) gene and susceptibility of rheumatoid arthritis (RA).MethodsWe systemically extracted the genetic data of miR-146a from previous genome-wide association studies (GWASs) of RA. Subsequently, we performed a replication study in an independent Chinese cohort for selected variant. A meta-analysis combined the previous GWASs with the replication study was also conducted. The epigenetic annotation and cytokine assay were used for exploring potential variant function.ResultsThe extracted genetic association data from three previous GWASs showed that the allele T of functional SNP rs2431697 increased RA susceptibility. The significant association for the SNP was also found in the Chinese replication cohort (OR = 1.24, 95% CI = 1.06–1.46, p = 8.69E-03). The estimated effect size for this SNP was larger in Asian population than that in European population (Asian meta-analysis: OR = 1.15, 95% CI = 1.09–1.22, p = 4.37E-07; Tran-ethnic meta-analysis: OR = 1.07, 95% CI = 1.04–1.10, p = 1.79E-06). The cytokine assay also showed that the risk allele T of the SNP rs2431697 is inversely associated with plasma TNF-α levels in health controls (p = .016).ConclusionsIn summary, this study supports that genetic variant in miR-146a gene is associated with RA risk.

KEY MESSAGES

1. The association between SNPs in miR-146a gene and susceptibility of RA was unclear.
2. We investigated the genetic association using GWASs data and a replication study.
3. The SNP rs2431697 in miR-146a gene is associated with RA risk.