Understanding the pathophysiology of rheumatoid arthritis (RA) has led to the successful development of molecule-targeted drugs for the treatment of RA. However, some RA patients are refractory to ...these treatments, suggesting that the pathological mechanism of the disease is not entirely understood. Genome and transcriptome analysis is essential for understanding the unknown pathophysiology of human diseases. Rapid and more comprehensive gene analysis technologies have revealed notable changes in the expression of coding RNA and non-coding RNA in RA patients. This review focuses on the current state of non-coding RNA research in relation to RA, especially on tRNA fragments. Interestingly, it has been found that tRNA fragments repress translation and are antiapoptotic. The association between tRNA fragments and various diseases has been studied, and this article reviews the possible role of tRNA fragments in RA.
Abstract
Background
Monogenic autoinflammatory diseases are caused by pathogenic variants in genes that regulate innate immune responses, and are characterized by sterile systemic inflammatory ...episodes. Since symptoms can overlap within this rapidly expanding disease category, accurate genetic diagnosis is of the utmost importance to initiate early inflammation-targeted treatment and prevent clinically significant or life-threatening complications. Initial recommendations for the genetic diagnosis of autoinflammatory diseases were limited to a gene-by-gene diagnosis strategy based on the Sanger method, and restricted to the 4 prototypic recurrent fevers (MEFV, MVK, TNFRSF1A, and NLRP3 genes). The development of best practices guidelines integrating critical recent discoveries has become essential.
Methods
The preparatory steps included 2 online surveys and pathogenicity annotation of newly recommended genes. The current guidelines were drafted by European Molecular Genetics Quality Network members, then discussed by a panel of experts of the International Society for Systemic Autoinflammatory Diseases during a consensus meeting.
Results
In these guidelines, we combine the diagnostic strength of next-generation sequencing and recommendations to 4 more recently identified genes (ADA2, NOD2, PSTPIP1, and TNFAIP3), nonclassical pathogenic genetic alterations, and atypical phenotypes. We present a referral-based decision tree for test scope and method (Sanger versus next-generation sequencing) and recommend on complementary explorations for mosaicism, copy-number variants, and gene dose. A genotype table based on the 5-category variant pathogenicity classification provides the clinical significance of prototypic genotypes per gene and disease.
Conclusions
These guidelines will orient and assist geneticists and health practitioners in providing up-to-date and appropriate diagnosis to their patients.
Thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly (TAFRO) syndrome is a systemic inflammatory disorder characterized by the above-mentioned symptoms. Because of the similarity ...in phenotypes between TAFRO syndrome and decompensated liver cirrhosis, an accurate diagnosis is often difficult. We herein report a 62-year-old Japanese patient with TAFRO syndrome who was misdiagnosed with intractable ascites associated with liver cirrhosis. Improvement of symptoms after treatment with prednisolone was associated with interleukin-6 rather than C-reactive protein. The pathogenesis of TAFRO syndrome, which has similar clinical manifestations to liver cirrhosis, remains unclear, and our findings may help elucidate the concept of this condition.
We herein report an unusual case of granulomatosis with polyangiitis (GPA) in a 65-year-old man in whom relapsed disease manifested as an anterior cheek nodule. Magnetic resonance imaging indicated ...the differential diagnoses of the subcutaneous nodule in the patient's anterior cheek to be inflammatory granulomatous lesions with GPA, malignancy, or infectious disease. A histopathological examination ruled out malignancy and infectious diseases, and necrotizing vasculitis was suspected. The subcutaneous nodule was successfully treated using rituximab, suggesting that it was associated with GPA, secondary to vasculitis. Clinicians should be aware of the possibility of such a rare manifestation of GPA.
Next, the IL-1β secretion from macrophages derived from monocytes in vitro (peripheral blood–derived macrophages PB-MPs) was evaluated. Because TcdA stimulation alone did not induce IL-1β secretion ...from PB-MPs (data not shown), PB-MPs were primed with LPS before TcdA stimulation. ...by examining both cell types from the same patients, we revealed the overall picture of the cytokine responses of monocytes and macrophages from patients with FMF. Induced pluripotent stem cell (iPSC) technology provides the opportunity to analyze the effect of genetic variants free from the influence of medication or differences in genetic background. ...we evaluated whether macrophages derived from patients' iPSCs (iPSC-derived macrophages iPS-MPs) recapitulated the phenotype of PB-MPs from patients with FMF. iPSC lines from 3 patients with FMF with the M694I and E148Q MEFV variants were established (patients 6-8; see Fig E2 and Table E1 in this article's Online Repository at www.jacionline.org) and differentiated into iPS-MPs (see Fig E3 in this article's Online Repository at www.jacionline.org). iPS-MPs with the M694I mutation recapitulated the enhanced pyrin inflammasome activation of PB-MPs, leading to increased IL-1β secretion (Fig 2, A), ASC speck formation (Fig 2, B), and cell death, which was dependent on MEFV expression (see Fig E4 in this article's Online Repository at www.jacionline.org). ...we applied our newly established method to 2 additional MEFV variants, T577N and N679H, which were identified in 2 families in which autoinflammatory disease with dominant inheritance was suspected.
Nakajo-Nishimura syndrome (NNS) is a disorder that segregates in an autosomal recessive fashion. Symptoms include periodic fever, skin rash, partial lipomuscular atrophy, and joint contracture. Here, ...we report a mutation in the human proteasome subunit beta type 8 gene (PSMB8) that encodes the immunoproteasome subunit β5i in patients with NNS. This G201V mutation disrupts the β-sheet structure, protrudes from the loop that interfaces with the β4 subunit, and is in close proximity to the catalytic threonine residue. The β5i mutant is not efficiently incorporated during immunoproteasome biogenesis, resulting in reduced proteasome activity and accumulation of ubiquitinated and oxidized proteins within cells expressing immunoproteasomes. As a result, the level of interleukin (IL)-6 and IFN-γ inducible protein (IP)-10 in patient sera is markedly increased. Nuclear phosphorylated p38 and the secretion of IL-6 are increased in patient cells both in vitro and in vivo, which may account for the inflammatory response and periodic fever observed in these patients. These results show that a mutation within a proteasome subunit is the direct cause of a human disease and suggest that decreased proteasome activity can cause inflammation.
Objective Familial Mediterranean Fever (FMF) is the most frequent autoinflammatory syndrome, and its frequency is reported to be increasing in Japan. We studied the clinical features and genetic ...background of patients with FMF in our hospital. Methods We analyzed the clinical features and genomic variants of MEFV, as well as 10 genes related to other autoinflammatory syndromes, in 22 Japanese patients with FMF. A genetic analysis was performed with a next generation sequencer. Results The patients were classified into the typical FMF (n=16) and atypical FMF (n=6) groups. Fever, abdominal pain, thoracic pain, and arthralgia were observed in 22, 12, 8, and 10 patients, respectively. MEFV variants were found in 19 patients (86.4%). Two cases had no MEFV variants and one case only had a variant in the 3′ untranslated region (3′-UTR) of MEFV. Genomic variants were found in genes other than MEFV in 7 patients (31.8%); however, none met the diagnostic criteria for autoinflammatory syndromes with disease-related gene variants, and all were classified as typical FMF. Moreover, none of the 6 patients with atypical FMF had any variants among the 10 disease-related genes. All cases in which the onset occurred before 20 years of age were classified as typical FMF. Conclusion The clinical features of FMF recorded in our hospital coincided with those from the Japanese national epidemiological survey of FMF in Japan. More than 30% of the patients with FMF had non-MEFV genes, related to other autoinflammatory syndromes, thereby suggesting that variants of these genes may act as a disease-modifier in FMF.
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