Examination of Prognostic Factors in Anti-Melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis.

OBJECTIVE: This study investigated the prognostic factors of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (MDA5-DM). METHODS: This study analysed 34 MDA5-DM cases (20 and 14 in the survival and death groups, respectively) encountered at Kurume University between 2008 and 2021. The clinical, physiological, and computed tomography findings, pulmonary function, and serological results were retrospectively evaluated for each MDA5-DM case during the first visit and throughout the next 12 weeks. RESULTS: In the death group, the mean age of patients was higher (47.6 vs. 61.8 years), while the duration from symptom onset to consultation was shorter (110 vs. 34.9 days). During the first visit, the death group demonstrated a significantly higher serum C-reactive protein (CRP) level (0.52 vs. 1.99) and a significantly lower albumin level (3.23 vs. 2.63) than the survival group; this persisted throughout the next 12 weeks. Poor prognosis was associated with CRP and albumin levels above 0.19 mg/dL and below 2.3 g/dL, respectively, 4 weeks after starting treatment. CONCLUSION: Four weeks after beginning treatment, serum CRP and albumin levels of patients with MDA5-DM can be used to evaluate treatment response and predict prognosis.

Mast cells can produce transforming growth factor ß1 and promote tissue fibrosis during the development of Sjögren's syndrome-related sialadenitis.

OBJECTIVES: This study investigated the associations of mast cells with immune-mediated inflammation and fibrosis in patients with primary Sjögren's syndrome (pSS); it also explored the underlying pathophysiology of pSS-related sialadenitis. METHODS: Twenty-two patients with pSS and 10 patients with sicca (control individuals) underwent labial salivary gland biopsies. Sections were subjected to staining and immunofluorescence analyses. HMC-1 human mast cells were cocultured with fibroblasts in vitro; fibroblasts were also grown in HMC-1 conditioned medium. mRNA levels of collagen Type I (Col1a) and transforming growth factor (TGF)ß1 were analysed in cultured cells. RESULTS: Mast cell numbers in labial salivary glands were significantly greater in patients with pSS than in control individuals. In salivary glands from patients with pSS, mast cell number was significantly correlated with fibrosis extent; moreover, mast cells were located near fibrous tissue and expressed TGFß1. Col1a and TGFß1 mRNAs were upregulated in cocultured fibroblasts and HMC-1 cells, respectively. Fibroblasts cultured in HMC-1 conditioned medium exhibited upregulation of Col1a mRNA; this was abrogated by TGFß1 neutralizing antibodies. CONCLUSIONS: Mast cell numbers were elevated in patients with pSS-related sialadenitis; these cells were located near fibroblasts and expressed TGFß1. TGFß1 could induce collagen synthesis in fibroblasts, which might contribute to fibrosis.

Possible Roles of tRNA Fragments, as New Regulatory ncRNAs, in the Pathogenesis of Rheumatoid Arthritis.

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.

MEFV E148Q variant is more associated with familial Mediterranean fever when combined with other non-exon 10 MEFV variants in Japanese patients with recurrent fever.

OBJECTIVE: To investigate the genetic characteristics of one of the MEFV gene variants, p.Glu148Gln (E148Q), in patients with familial Mediterranean fever (FMF) and examine its significance in Japanese patients with recurrent fever. METHODS: The clinical phenotype and genomic variants of systemic autoinflammatory diseases (SAIDs), including MEFV, were analyzed in 211 Japanese patients with recurrent fever. Genetic analysis was performed via next-generation sequencing of exons, including exon-intron boundaries. RESULTS: Twelve patients met the diagnostic criteria for SAIDs other than FMF. Considering 199 patients with recurrent fever, 137 cases (68.8%) were clinically diagnosed with FMF. Although Bonferroni-adjusted p-value did not reach significance level, the group containing heterozygous E148Q and other variants tended to be at higher risk of developing the FMF phenotype (nominal p = .036) than the group with heterozygous E148Q only. Comparison between the group with heterozygous E148Q and other variants and the heterozygous group containing non-E148Q showed no statistically significant difference in FMF phenotype expression (nominal p = 1.00). CONCLUSION: Patients with heterozygous E148Q and other variants exhibited higher expression of FMF phenotype than those with heterozygous E148Q only, and suggested that other variants than E148Q as well as exon 10 variants might contribute to the FMF phenotype.

Clinical phenotypes and genetic analyses for diagnosis of systemic autoinflammatory diseases in adult patients with unexplained fever.

OBJECTIVE: To make an accurate diagnosis of systemic autoinflammatory diseases (SAIDs), clinical and genetic analyses were performed in patients with unexplained fever. METHODS: The clinical phenotype and genomic variants of 11 genes responsible for SAIDs were analyzed in 179 Japanese patients with unexplained fever. Genetic analysis was performed by next generation sequencing (NGS) on exons including exon-intron boundaries. RESULTS: Three cases met the diagnostic criteria for SAIDs other than familial Mediterranean fever (FMF). Considering 176 patients with unexplained fever, 43 cases (24.0%) were clinically diagnosed as FMF. Gene variants were found in 53 cases (30.1%) when searching for variants in the 10 disease genes other than the MEFV gene. Among them, the most frequently-identified genes were NLRP3, NOD2, NLRP12, NLRC4, and PLCG2, which accounted for 14, 7, 17, 7, and 6 cases, respectively. These variants were less than 1% of healthy individuals or novel variants, but not regarded as pathogenic since the patients did not meet the diagnostic criteria of SAIDs caused by their identified variants clinically. CONCLUSION: Twenty four percent of Japanese patients with unexplained fever were clinically diagnosed as FMF in this study. Low frequency but not pathogenic variants in genes other than MEFV were identified in 30.1% of the cases. It is not clear how much these gene variants contribute to the inflammatory phenotypes; therefore, further analysis would uncover their autoinflammatory phenotypes that cause fever.

ISSAID/EMQN Best Practice Guidelines for the Genetic Diagnosis of Monogenic Autoinflammatory Diseases in the Next-Generation Sequencing Era.

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.

Intracellular Dynamics and Fate of a Humanized Anti-Interleukin-6 Receptor Monoclonal Antibody, Tocilizumab.

Tocilizumab (TCZ), a humanized anti-interleukin-6 (IL-6) receptor (IL-6R) monoclonal antibody, abrogates signal transducer protein gp130-mediated IL-6 signaling by competitively inhibiting the binding of IL-6 to the receptor, and shows clinical efficacy in autoimmune and inflammatory diseases. Despite accumulating evidence for therapeutic efficacy, the behavior and fate of TCZ at the cellular level remain largely unknown. To address this, we evaluated the endocytosis and intracellular trafficking of IL-6R in HeLa cells. The results of our study provide evidence that IL-6R is constitutively internalized from the cell surface by ligand or TCZ binding and the expression of gp130 in an independent manner and is targeted via endosomes without being significantly directed to the recycling pathway to, and degraded in, lysosomes. Furthermore, the cytoplasmic tail of IL-6R is required for constitutive endocytosis of the receptor, which is mediated by the clathrin and AP-2 complex. We further demonstrate that FcRn, whose function is to regulate the serum persistence of IgG, is confined primarily to early/recycling endosomes and rapidly transits between these compartments and late endosomes/lysosomes without being degraded. Importantly, the expression of FcRn induces the segregation of TCZ from IL-6R, resulting in extensive colocalization of TCZ and FcRn in IL-6R-depleted endosomal compartments. Collectively, our results suggest that FcRn can accelerate the retrieval of the internalized TCZ, not only from endosomes but also from lysosomes. Our findings provide new insight into the mechanism by which the antibody internalized into cells is rescued from lysosomal degradation and into how its serum levels are maintained.

An autopsy case of refractory vasculo-Behçet's disease.

Pulmonary vascular involvement in Behçet's disease is a rare complication with a poor prognosis. We present an autopsy case of vasculo-Behçet's disease complicated by pulmonary hemorrhage, possibly caused by rupture of pulmonary artery aneurysms. The patient was treated with a combination of high-dose steroids and pulse cyclophosphamide, but he died from massive hemoptysis. This case highlights the need for potent new therapies for patients with vasculo-Behçet's disease refractory to conventional immunosuppressive therapy, such as a combination of steroids and cyclophosphamide.

Successful treatment of macrophage activation syndrome in a patient with dermatomyositis by combination with immunosuppressive therapy and plasmapheresis.

Macrophage activation syndrome (MAS), also known as secondary hemophagocytic lymphohistiocytosis, is mediated by cytokine overproduction from excessive activation of T lymphocytes and macrophages. We present a dermatomyositis patient with MAS, caused by hypercytokinemia. The combination of tacrolimus and plasma exchange therapy was effective in this case for treating MAS. This combination therapy is especially useful for MAS refractory to steroids.

Serum interferon-α is a useful biomarker in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis.

OBJECTIVE: We have tried to clarify the clinical importance of the measurement of serum type-I interferon (IFN) in patients with anti-melanoma differentiation-associated gene 5 Ab (MDA5 Ab)-positive dermatomyositis (DM). METHODS: We studied 30 patients with DM: 10 were anti-MDA5 Ab-positive and 20 were anti-MDA5 Ab-negative. At each patient's initial visit, serum IFN-α, IFN-ß, interleukin 18 (IL-18), ferritin, and the titer of anti-MDA5 Ab were measured using enzyme-linked immunosorbent assays (ELISAs). The associations between the IFNs and with the other variables were examined. RESULTS: Rapidly progressive interstitial lung disease (RPILD) was confirmed in 10 patients, most of whom were complicated in the anti-MDA5 Ab-positive DM patients. The presence of clinically amyopathic dermatomyositis (CADM) as well as the serum concentrations of IFN-α and ferritin was significantly higher in the anti-MDA5 Ab-positive DM patients. Serum concentration of IL-18 did not differ between anti-MDA5 Ab-positive and anti-MDA5 Ab-negative groups; however, a positive correlation was found between IFN-α and IL-18 in the anti-MDA5 Ab-positive DM patients (r = 0.8139, p = 0.0146). CONCLUSION: Serum IFN-α can be used as a useful biomarker in patients with anti-MDA5 Ab-positive DM, which may reflect the presence of RPILD.

[Pathogenesis and Clinical Examination of Autoinflammatory Syndrome].

Autoinflammatory syndrome is characterized by: 1) episodes of seemingly unprovoked inflammation, 2) the absence of a high titer of autoantibodies or auto-reactive T cells, and 3) an inborn error of innate immunity. In this decade, many autoinflammatory syndromes have been reported in Japan, and so many Japanese physicians have become aware of this syndrome. Monogenic autoinflammatory syndromes present with excessive systemic inflammation including fever, rashes, arthritis, and organ-specific inflammation and are caused by defects in single genes encoding proteins that regulate innate inflammatory pathways. The main monogenic autoinflammatory syndromes are familial Mediterranean fever (FMF), TNF receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), cryopyrin-associated periodic syndrome (CAPS), Blau syndrome, and syndrome of pyogenic arthritis with pyoderma gangrenosum and acne (PAPA). We diagnosed these syndromes as clinical manifestations and performed genetic screening. Many serum cytokines are elevated in patients with autoinflammatory syndrome, but this is not disease-specific. The pathogeneses of many autoinflammatory syndromes are known to be related to inflammasomes, which are multiprotein complexes that serve as a platform for caspase 1 activation and interleukin-1ß(IL-1ß) and IL-18 maturation. Especially, NLRP3 inflammasomes may play a crucial role in the initiation and progression of FMF and CAPS. Recently, it was reported that NETs (neutrophil extracellular traps) derived from neutrophils may also play an important role in the pathogenesis of FMF. In the future, we hope to discover new clinical examinations which can provide evidence of inflammasome activation independent of genetic screening. In this issue, I introduce autoinflammatory syndromes and discuss the pathogenesis and clinical examination of these syndromes.

[Diagnosis and Clinical Examination of Autoinflammatory Syndrome].

Autoinflammatory syndrome is characterized by: 1) episodes of seemingly unprovoked inflammation, 2) the absence of a high titer of autoantibodies or auto-reactive T cells, and 3) an inborn error of innate immunity. In this decade, many autoinflammatory syndromes have been reported in Japan, and so many Japanese physicians have become aware of this syndrome. Monogenic autoinflammatory syndromes present with excessive systemic inflammation including fever, rashes, arthritis, and organ-specific inflammation and are caused by defects in single genes encoding proteins that regulate innate inflammatory pathways. The main monogenic autoinflammatory syndromes are familial Mediterranean fever (FMF), TNF receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), cryopyrin-associated periodic syndrome (CAPS), Blau syndrome, and pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome. We diagnosed these syndromes as clinical manifestations and performed genetic screening. Many serum cytokines are elevated in patients with autoinflammatory syndrome, but this is not disease-specific. The pathogeneses of many autoinflammatory syndromes are known to be related to inflammasomes, which are multiprotein complexes that serve as a platform for caspase 1 activation and interleukin-1ß (IL-1ß) and IL-18 muturation. Especially, NLRP3 inflammasomes may play a crucial role in the intiation and progression of FMF and CAPS. In the future, we hope to discover new clinical examinations which can provide evidence of inflammasome activation independent of genetic screening. In this issue, I introduce autoinflammatory syndromes and discuss the diagnosis and clinical examination of these syndromes.

Proteasome assembly defect due to a proteasome subunit beta type 8 (PSMB8) mutation causes the autoinflammatory disorder, Nakajo-Nishimura syndrome.

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 ß5i in patients with NNS. This G201V mutation disrupts the ß-sheet structure, protrudes from the loop that interfaces with the ß4 subunit, and is in close proximity to the catalytic threonine residue. The ß5i 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.

Successful treatment of rectal ulcers in a patient with systemic lupus erythematosus using corticosteroids and tacrolimus.

Systemic lupus erythematosus (SLE) is frequently accompanied by gastrointestinal symptoms. Although all parts of the gastrointestinal tract may be affected, colonic involvement is quite rare. Colonic ulceration, particularly in the rectum, is associated with a high mortality rate in patients with SLE, despite immunosuppressive therapy. While a standard regimen for treating rectal ulcers as a complication of SLE has not been established, combination therapy with steroids and immunosuppressive agents is necessary because of the associated high mortality rate. In this report, we describe a patient with SLE whose condition was complicated with ulcerative lesions in the rectum and sigmoid colon; the lesions were successfully treated with a combination of corticosteroids and tacrolimus therapy. Tacrolimus could be a useful additional or alternative modality for treating rectal involvement in SLE.

Clinical, serologic and magnetic resonance imaging of 3 cases of inflammatory myopathy with abundant macrophages in the Japanese population.

We report the first 3 cases of inflammatory myopathy with abundant macrophages (IMAM) to be found in an Asian country. Diagnosis of IMAM was based on the infiltration of CD68+ macrophages into biopsied specimens, particularly the fascia. Proximal skeletal muscle symptoms and signs, elevation of creatine kinase, and myogenic changes in electromyography were found in all of the cases, and magnetic resonance imaging clearly revealed thickening of the fascia. Since dermatomyositis (DM)-specific skin alterations were not found, none of the patients in this study fulfilled Bohan and Peter's criteria for DM; however, anti-PL-7 antibody was detected in case number 1. In addition, CD20+ B-cell infiltration into the fascia was also detected in all of the cases, indicating further transition to DM. Severe illness, namely macrophage activation syndrome and acute respiratory distress syndrome, occurred in case 1 but was resolved with intensive combination therapy. The other 2 cases also required glucocorticoids to achieve remission.

Significant improvement in MRI-proven bone edema is associated with protection from structural damage in very early RA patients managed using the tight control approach.

OBJECTIVE: To identify the value of magnetic resonance imaging (MRI)-proven bone edema in patients with very early rheumatoid arthritis (RA). METHODS: All of the 13 patients included in the study were positive at entry for MRI-proven bone edema of the wrist and finger joints and anti-cyclic citrullinated peptide antibodies or IgM-rheumatoid factor. A tight control approach was applied for 12 months. Plain MRI and radiographs of both wrist and finger joints were examined every 6 months. MRI was scored by the RA MRI scoring (RAMRIS) technique and plain radiographs were scored using the Genant-modified Sharp score. Variables that were correlated with plain radiographic changes at 12 months were examined. RESULTS: Simplified disease activity index (SDAI) remission was achieved in 7 patients, and a significant reduction in the RAMRIS bone edema score, which declined to <33 % as compared with the baseline, was achieved in 8 out of 13 patients. Four patients showed plain radiographic progression while 9 patients did not. Significant reductions in the RAMRIS bone edema score (p = 0.007) and the time-integrated SDAI (p = 0.031) were the variables involved in plain radiographic progression. CONCLUSIONS: Improvement in bone edema may be associated with protection against structural damage in very early RA patients managed using the tight control approach.