Human leucocyte antigens and Japanese patients with polymyalgia rheumatica: the protective effect of DRB1*09:01.

OBJECTIVE: The hallmarks of the chronic inflammatory disease polymyalgia rheumatica (PMR) include pain, and morning stiffness in areas of the neck, shoulder and pelvic girdle. The human leucocyte antigen (HLA) gene was reported to be an important risk factor for PMR, but it has not been analysed precisely, especially in populations other than Europeans. METHODS: Genotyping of DRB1 and DQB1 was performed in Japanese PMR patients (n=270) and controls (n=413). Associations between allele carrier and genotype frequencies were determined for PMR. RESULTS: DRB1*04:05 was associated with a predisposition to PMR (p=0.0006, Pc=0.0193, OR 1.85, 95% CI 1.31 to 2.62). DRB1*09:01 was associated with protection against PMR (p=1.46×10-5, Pc=0.0004, OR 0.40, 95% CI 0.26 to 0.61). A shared epitope (SE) associated with PMR (p=3.07×10-6, OR 2.11, 95% CI 1.54 to 2.88). DQB1*03:03 (p=0.0010, Pc=0.0140, OR 0.52, 95% CI 0.35 to 0.77) was associated with protection against PMR and DQB1*04:01 (p=0.0009, Pc=0.0140, OR 1.82, 95% CI 1.28 to 2.58) was associated with predisposition to PMR. A gene dosage effect was observed for DRB1*09:01 and DQB1*03:03, but not for DRB1*04:05, SE or DQB1*04:01. Haplotype and logistic regression analyses suggested a protective effect for DRB1*09:01. CONCLUSION: This study is the first to demonstrate predisposing associations of DRB1*04:05, SE, and DQB1*04:01, and protective associations of DRB1*09:01 and DQB1*03:03 with PMR in Japanese patients. Our data indicate HLA has predisposing and protective effects on the pathogenesis of PMR.

The contributions of deleterious rare alleles in NLRP12 and inflammasome-related genes to polymyalgia rheumatica.

Polymyalgia rheumatica (PMR) is a chronic inflammatory disease characterized by arthralgia and myalgia of the shoulder and hip girdles, and fever. PMR is linked to autoimmune diseases and autoinflammatory disorders. Exome sequencing has revealed the roles of rare variants in some diseases. Causative genes for monogenic autoinflammatory disorders might be candidate genes for the selective exome analysis of PMR. We investigated rare variants in the coding and boundary regions of candidate genes for PMR. Exome sequencing was performed to analyze deleterious rare variants in candidate genes, and the frequencies of the deleterious rare alleles in PMR were compared with those of Japanese population controls. Deleterious rare alleles in the NLRL12 gene were associated with PMR (P = 0.0069, Pc = 0.0415, odds ratio [OR] 4.49, 95% confidence interval [CI] 1.79-11.27). A multigene analysis demonstrated the deleterious rare allele frequency of the candidate genes for autoinflammatory disorders was also increased in PMR (P = 0.0016, OR 3.69, 95%CI 1.81-7.54). The deleterious rare allele frequencies of the candidate genes including NLRP12 were increased in PMR patients, showing links to autoinflammatory disorders in the pathogenesis of PMR.

Trends in Treatment for Patients with Late-onset Rheumatoid Arthritis in Japan: Data from the NinJa Study.

OBJECTIVES: To investigate trends in the treatment of patients with late-onset rheumatoid arthritis (LORA) using data from the National Database of Rheumatic Diseases in Japan (NinJa). METHODS: Patients registered in the NinJa were classified according to disease onset: at <65 years (young-onset rheumatoid arthritis [YORA]); at 65-74 years (early LORA); and at ≥75 years (late LORA). Chronological changes in the treatment and disease activity were compared. RESULTS: A total of 7,178, 13,171, 15,295, and 15,943 patients were evaluated in 2010, 2013, 2016, and 2019, respectively. In all groups, the use of methotrexate gradually decreased, whereas that of biological/targeted synthetic disease-modifying antirheumatic drugs (DMARDs) increased; the use of tumor necrosis factor inhibitors (TNFi) decreased, whereas that of non-TNFi increased. LORA was characterized by more single DMARD use, and less methotrexate and biological/targeted synthetic DMARD use. TNFi and interleukin-6 inhibitors were used less frequently, whereas abatacept was utilized more frequently in late versus early LORA. Conventional synthetic DMARD (excluding methotrexate) and glucocorticoid use was higher in late versus early LORA. CONCLUSIONS: This analysis revealed chronological changes in the treatment of LORA in Japan. Differences between early and late LORA suggest that patients are not a homogeneous population.

Comparison between rheumatoid arthritis with malignant lymphoma and other malignancies: Analysis of a National Database of Rheumatic Disease in Japan.

BACKGROUND: The background status and the current treatment options of patients with rheumatoid arthritis (RA) who develop malignant lymphoma (ML) and other malignancies are unclear. This study investigated the differences in background factors between ML and other malignancies that occur in RA patients and post-malignancy treatment. METHODS: We identified 935 RA patients with new-onset malignancies among 110,571 person-years registered in the National Database of Rheumatic Disease in Japan from 2012 to 2018. Analysis cohorts 1 and 2 included 597 and 490 patients with available data for 1 year before and after the development of malignancies, respectively. Factors associated with the development of ML were longitudinally evaluated by multiple logistic regression analyses. RESULTS: Of the 935 patients (mean age 70.5, standard deviation 9.9), 15.5% had ML; this was comparable to the rate of lung cancer (14.3%). In cohort 1, methotrexate (MTX), biological disease-modifying anti-rheumatic drugs (bDMARDs), and non-steroidal anti-inflammatory drugs (NSAIDs) were used in 74.4%, 23.4%, and 56.7% of ML and in 56.8%, 25.4%, and 35.3% of other malignancies 1 year before the occurrence of malignancies. Clinical disease activity index (CDAI) and C-reactive protein were similar between the two groups. Multivariable analysis showed that MTX use (odds ratio [OR]: 2.22, 95% CI [confidence interval]: 1.32-3.73, p=0.003) and NSAID use (OR: 2.51, 95% CI: 1.58-3.98, p <0.001) were significantly associated with the development of ML versus other malignancies. However, this association was not observed with bDMARDs. In cohort 2, one year after the development of malignancies, MTX was used in none of ML and 41.8% of patients who developed other malignancies. In both malignancy groups, approximately 15% of patients received bDMARDs and 50% received glucocorticoids. IL-6 inhibitors were preferentially prescribed in patients with ML versus those with other malignancies. At year 1, CDAI remission was achieved in 37.3% and 31.1% of patients in the ML and other malignancy groups, respectively. CONCLUSION: Patients receiving long-term treatment with MTX and NSAIDs may be at a relatively high risk of developing ML. The treatment landscape after developing malignancies differed considerably between patients with ML and other malignancies, and different treatment strategies should be established.

Association of a Single Nucleotide Variant in TERT with Airway Disease in Japanese Rheumatoid Arthritis Patients.

Interstitial lung disease and airway disease (AD) are often complicated with rheumatoid arthritis (RA) and have a poor prognosis. Several studies reported genetic associations with interstitial lung disease in RA. However, few genetic studies have examined the susceptibility to AD in RA patients. Here, we investigated whether single nucleotide variants susceptible to idiopathic pulmonary fibrosis might be associated with interstitial lung disease or AD in Japanese RA patients. Genotyping of rs2736100 [C/A] in TERT and rs1278769 [G/A] in ATP11A was conducted in 98 RA patients with usual interstitial pneumonia, 120 with nonspecific interstitial pneumonia (NSIP), 227 with AD, and 422 without chronic lung disease using TaqMan assays. An association with AD in RA was found for rs2736100 (p = 0.0043, Pc = 0.0129, odds ratio [OR] 1.40, 95% confidence interval [CI] 1.11-1.77). ATP11A rs1278769 was significantly associated with NSIP in older RA patients (>65 years, p = 0.0010, OR 2.15, 95% CI 1.35-3.40). This study first reported an association of rs2736100 with AD in RA patients and ATP11A rs1278769 with NSIP in older RA patients.

Associations of HLA Polymorphisms with Chronic Kidney Disease in Japanese Rheumatoid Arthritis Patients.

OBJECTIVES: The prevalence of chronic kidney disease (CKD) was reported to be higher in rheumatoid arthritis (RA) patients than in normal healthy individuals. Human leukocyte antigen (HLA) was associated with RA or CKD. Few studies on the association of HLA with CKD in RA have been reported. Here, we investigated the association of HLA polymorphisms with CKD in Japanese RA patients. METHODS: HLA-DRB1 genotyping was conducted in 351 Japanese RA patients with CKD (estimated glomerular filtration rate [eGFR] lower than 60 [mL/min/1.73 m2]) and 959 without CKD (eGFR equal to or higher than 60 [mL/min/1.73 m2]). Associations of allele carrier frequencies of DRB1 with CKD were examined in the RA patients. RESULTS: There was an association of DRB1*13:02 with CKD in RA, but this did not achieve statistical significance (p = 0.0265, odds ratio [OR] 1.70, pc = 0.7412, 95% confidence interval [CI] 1.09-2.64). The DR6 serological group was associated with CKD in RA (p = 0.0008, OR 1.65, 95% CI 1.24-2.20). A gene-dosage effect of DR6 was not detected. Logistic regression analysis showed that the association of DR6 with CKD in RA was independent of clinical characteristics. CONCLUSIONS: The present study first revealed the independent predisposing association of DR6 with CKD in Japanese RA patients, although DR6 is known to be protective against RA. Our data suggest direct or indirect roles of HLA for the development of CKD in RA, but the mechanisms are not clear.

Comprehensive evaluation of the influence of sex differences on composite disease activity indices for rheumatoid arthritis: results from a nationwide observational cohort study.

BACKGROUND: The effects and their magnitudes of sex on disease activity indices for rheumatoid arthritis are not clear. We aimed to comprehensively evaluate the influence of sex on disease activity indices in the real-world setting using a large observational database. METHODS: We analyzed 14,958 patients registered in the National Database of Rheumatic Diseases in Japan (NinJa) in 2017. We evaluated the sex differences in the 28-joint disease activity score (DAS28) using erythrocyte sedimentation rate (ESR), DAS28 using C-reactive protein (DAS28-CRP), Simplified Disease Activity Index (SDAI), and Clinical Disease Activity Index by disease activity category using Cliff's delta and regression analysis. Differences in the share of components of indices were evaluated using permutational multivariate analysis of variance. Correction equations were constructed to estimate the number of misclassification in male patients who achieve DAS28-ESR remission. RESULTS: DAS28-ESR showed higher values in female patients than male patients in remission despite no obvious difference in other indices or disease activity categories. Among the components of DAS28-ESR, only ESR was higher in female patients than male patients in remission. In DAS28-CRP and SDAI, 28-tender joint count was higher and CRP was lower in female patients than male patients. In addition, the profiles in the components were different between female and male patients, especially among those with high disease activity. Using correction equations, almost 12% of male patients with DAS28-ESR remission were estimated to be misclassified, mainly due to differences in ESR. CONCLUSION: Among the disease activity indices, significant sex difference was observed only in DAS28-ESR remission. The degree of misclassification in DAS28-ESR remission would be unignorable.

Antibodies against Serum Anti-Melanoma Differentiation-Associated Gene 5 in Rheumatoid Arthritis Patients with Chronic Lung Diseases.

Chronic lung diseases (CLD), including interstitial lung disease (ILD) and airway diseases (ADs), are common complications of rheumatoid arthritis (RA). Rheumatoid factor (RF) and anti-citrullinated peptide antibodies are reported to be associated with CLD in RA patients. The presence of anti-melanoma differentiation-associated gene 5 (MDA5) antibodies (Abs) is associated with clinically amyopathic dermatomyositis developing into rapidly progressive ILD. However, few studies on anti-MDA5 Abs in RA have been published. Here, we analyzed the association of anti-MDA5 Abs with CLD complications in RA. Anti-MDA5 Abs were quantified in sera from RA patients with or without CLD. Anti-MDA5 Ab levels were higher in RA patients with ADs than without (mean ± SDM, 4.4 ± 2.4 vs. 4.0 ± 4.2, p = 0.0001). AUC values of anti-MDA5 Ab and RF ROC curves were similar in RA patients with or without CLD (0.578, 95%CI 0.530-0.627 and 0.579, 95%CI 0.530-0.627, respectively, p = 0.9411). Multiple logistic regression analysis of anti-MDA5 Abs and clinical characteristics yielded an MDA5-index with a higher AUC value than anti-MDA5 Ab alone (0.694, 95%CI 0.648-0.740, p = 5.08 × 10-5). Anti-MDA5 Abs were associated with ADs in RA patients and could represent a biomarker for CLD, similar to RF. The involvement of anti-MDA5 Abs in the pathogenesis of ADs in RA is proposed.

Associations of HLA Polymorphisms with Anti-SARS-CoV-2 Spike and Neutralizing Antibody Titers in Japanese Rheumatoid Arthritis Patients Vaccinated with BNT162b2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019. Anti-SARS-CoV-2 spike (S) and neutralizing antibodies (Abs) are measured to evaluate the efficacy of vaccines. Human leukocyte antigen (HLA) may be associated with vaccine efficacy. Here, we investigated the association of HLA polymorphisms with the production of anti-SARS-CoV-2 S or neutralizing Abs in vaccinated rheumatoid arthritis (RA) patients in Japan. Genotyping of DRB1 and DQB1 was conducted in 87 Japanese RA patients vaccinated with BNT162b2. Associations of allele or haplotype carrier frequencies with anti-SARS-CoV-2 S or neutralizing Abs were examined. DRB1*12:01 was significantly positively associated with the production of S Ab (p = 0.0225, odds ratio [OR] 6.08, 95% confidence interval [CI] 1.32-28.03). The DQB1*03:01 allele carrier frequency tended to be higher in high responders of S Ab. Allele carrier frequencies of DRB1*15:01 (p = 0.0102, OR 9.26, 95% CI 1.65-52.01) and DQB1*06:02 (p = 0.0373, OR 7.00, 95% CI 1.18-41.36) were higher in responders of neutralizing Ab. Haplotype and two-locus analyses of DRB1 and DQB1 suggested that DRB1 alleles were the primary drivers of these associations. Logistic regression analysis showed associations of these alleles independent of clinical characteristics. Independent associations were found between HLA alleles and anti-SARS-CoV-2 Ab production by vaccinated RA patients.

Association of a FAM13A variant with interstitial lung disease in Japanese rheumatoid arthritis.

BACKGROUND: Interstitial lung disease (ILD) occasionally occurs in rheumatoid arthritis (RA) and confers a dismal prognosis. We previously reported that a single-nucleotide variant (SNV) of MUC5B was associated with ILD in RA. However, the pathogenesis of ILD in Japanese patients with RA could not be explained solely by this SNV because its frequency is extremely low in the Japanese population. Here, we examined whether a different idiopathic pulmonary fibrosis susceptibility SNV might be associated with ILD in Japanese patients with RA. METHODS: Genotyping of rs2609255 (G/T) in FAM13A was conducted in 208 patients with RA with ILD and 420 without chronic lung disease using TaqMan assays. RESULTS: A significant association with usual interstitial pneumonia (UIP) in RA was detected for rs2609255 under the allele model (p=0.0092, Pc=0.0276, OR 1.53, 95% CI 1.12 to 2.11) and recessive model for the G allele (p=0.0003, Pc=0.0009, OR 2.63, 95% CI 1.59 to 4.32). FAM13A rs2609255 was significantly associated with UIP in male patients with RA (p=0.0043, OR 3.65, 95% CI 1.52 to 8.73) under the recessive model. CONCLUSIONS: This study is the first to document an association of rs2609255 with ILD in Japanese patients with RA, implicating it in the pathogenesis of UIP, though studies on the function of rs2609255 are warranted.

Leptin-producing monocytes in the airway submucosa may contribute to asthma pathogenesis.

BACKGROUND: Obesity leads to an increase in the incidence and severity of asthma. Adipokines, such as leptin, secreted by adipocytes induce systemic inflammation, causing airway inflammation. We previously reported that leptin activates both inflammatory and structural cells, including lung fibroblasts. However, little is known about the differential leptin expression and responsiveness to leptin in asthmatic individuals and healthy controls (HC). In this study, we investigated the expression and origin of leptin in asthmatic airways. We also compared the effect of leptin on asthmatic and HC fibroblasts. METHODS: Lung specimens from asthmatic and non-asthmatic patients were analyzed by immunohistochemical staining using anti-leptin and anti-CD163 antibodies. Leptin mRNA and protein levels in human monocytes were detected by real-time PCR and western blotting and ELISA, respectively. We used flow cytometry to analyze asthmatic and HC lung fibroblasts for leptin receptor (Ob-R) expression. Further, we determined cytokine levels using cytometric bead array and ELISA and intracellular phosphorylation of specific signaling molecules using western blotting. RESULTS: Asthma specimens displayed accumulation of leptin-positive inflammatory cells, which were also positive for CD163, a high-affinity scavenger receptor expressed by monocytes and macrophages. Leptin expression was observed at both transcript and protein levels in human blood-derived monocytes. No significant differences were observed between asthmatic and HC lung fibroblasts in Ob-R expression, cytokine production, and intracellular phosphorylation of p38 mitogen-activated protein kinase. CONCLUSIONS: Our findings reveal similar responsiveness of control and asthmatic fibroblasts to leptin. However, the accumulation of inflammatory leptin-producing monocytes in the airway may contribute to the pathogenesis of asthma.

Factors associated with impaired physical function in elderly rheumatoid arthritis patients who had achieved low disease activity.

OBJECTIVE: We aimed to investigate factors associated with impaired physical function (defined as HAQ Disability Index [HAQ-DI] >0.5) of old-old (aged 75-84) patients with rheumatoid arthritis (RA). METHODS: Data from 15,185 RA patients in the National Database of Rheumatic Disease in Japan were extracted from 2017 to 2018. We enrolled 3,708 patients aged 55-84 in simplified disease activity index (SDAI) ≤11 and Steinbrocker stage I/II. Factors associated with HAQ-DI >0.5 were analyzed by multivariable logistic regression. RESULTS: About half of the old-old patients received methotrexate, which was lower than middle-aged (55-64) and young-old patients (65-74). The proportion of glucocorticoids in the old-old patients was highest among the three groups, and biological disease-modifying anti-rheumatic drugs were similarly used. The prevalence of HAQ-DI >0.5 was significantly higher in old-old patients with low disease activity than in those with remission. The same was true in the middle-aged and young-old patients. Multivariable analysis showed age, higher SDAI, glucocorticoid use, and methotrexate non-use were significantly associated with HAQ-DI >0.5 in the old-old patients. CONCLUSIONS: SDAI remission was an ideal goal for old-old patients in terms of physical function. Glucocorticoids and a low proportion of methotrexate use may influence the physical function of old-old patients.

Anti-SARS-CoV-2 Spike Antibody Titers and Neutralizing Antibodies in Vaccinated Rheumatoid Arthritis Patients.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A serological test is used to assess the efficacy of vaccination. It has been reported that anti-SARS-CoV-2 spike (S) and neutralizing antibody (Ab) levels are lower following vaccination in patients with rheumatic disease. Here, we investigated anti-SARS-CoV-2 S and neutralizing Abs in vaccinated rheumatoid arthritis (RA) patients in Japan. Anti-SARS-CoV-2 S and neutralizing Abs were quantified in 101 RA patients and 117 controls. Anti-SARS-CoV-2 S Ab levels were lower in RA patients than both earlier after vaccination in controls (mean RA 324.1 ± 591.8 SDM vs. control 1216.6 ± 854.4 [U/mL], p < 0.0001) and later after vaccination (324.1 ± 591.8 vs. 582.0 ± 415.6 [U/mL], p = 0.0002). The interval between vaccination of the RA patients and serum collection was longer than for controls early after vaccination (142.1 ± 31.6 vs. 98.3 ± 11.2 [days], p < 0.0001), but shorter than the later sample from the controls (142.1 ± 31.6 vs. 257.3 ± 11.2 [days], p < 0.0001). Importantly, anti-SARS-CoV-2 neutralizing Ab titers in RA patients were higher than in either early or later control samples (10.7 ± 4.9 vs. 8.6 ± 6.6 [%], p = 0.0072, and 10.7 ± 4.9 vs. 3.1 ± 3.7 [%], p < 0.0001, respectively). Anti-SARS-CoV-2 S Ab titers in vaccinated RA patients were lower than in controls, but they were influenced by other clinical manifestations. Anti-SARS-CoV-2 neutralizing Ab levels were independently increased in RA.

Clinical variables, including novel joint index, associated with future patient-physician discordance in global assessment of rheumatoid arthritis (RA) disease activity based on a large RA database in Japan.

BACKGROUND: Discordance between patient global assessment (PGA) and physician global assessment (PhGA) of rheumatoid arthritis (RA) disease activity is mainly determined by pain and functional disabilities. This study aimed to investigate the shift in PGA-PhGA discordance and the variables associated with future positive discordance (PGA > PhGA) based on the NinJa database in Japan. METHODS: We examined 7557 adults with RA registered in both NinJa 2014 and 2018, with a discordance cutoff of 3 on a 10-cm scale. The affected joint distribution was investigated using the joint indices x, y, and z, which were calculated as indices for the upper joint, lower joint, and large joint involvement, respectively. The variables in NinJa 2014 that were associated with positive discordance in NinJa 2018 were examined using binary stepwise logistic regression analysis. RESULTS: Due to the small number of patients with RA categorized as having negative discordance (PGA < PhGA), we focused on patients with RA categorized as having either concordance or positive discordance. Logistic regression analysis revealed that positive discordance in NinJa 2018 was associated with age, pain, modified Health Assessment Questionnaire (mHAQ) score, corticosteroid use, and existent positive discordance and was inversely associated with C-reactive protein (CRP) and x at baseline (NinJa 2014). The same findings were observed when patients with RA were divided based on the discordance status at baseline. Persistence (positive discordance to positive discordance) was associated with pain and mHAQ scores but inversely associated with CRP. CONCLUSIONS: Positive discordance may persist. Circumventing this requires adequate management of pain and functional impairment.

Predisposition of HLA-DRB1*04:01/*15 heterozygous genotypes to Japanese mixed connective tissue disease.

Mixed connective tissue disease (MCTD) is a rare systemic autoimmune disease characterized by the production of anti-U1 ribonucleoprotein antibodies and systemic symptoms similar to those of some other autoimmune diseases. HLA-DRB1 polymorphisms are important genetic risk factors for MCTD, but precise associations of DRB1 genotypes with MCTD have not been reported in Japanese people. Genotyping of HLA-DRB1 and -DQB1 was performed in Japanese MCTD patients (n = 116) and controls (n = 413). Associations of specific allele carriers and genotype frequencies with MCTD were analyzed.The following alleles were found to be associated with predisposition to MCTD: HLA-DRB1*04:01 (P = 8.66 × 10-6, Pc = 0.0003, odds ratio [OR] 7.96, 95% confidence interval [CI] 3.13‒20.24) and DRB1*09:01 (P = 0.0189, Pc = 0.5468, OR 1.73, 95% CI 1.12‒2.67). In contrast, the carrier frequency of the DRB1*13:02 allele (P = 0.0032, Pc = 0.0929, OR 0.28, 95% CI 0.11‒0.72) was lower in MCTD patients than in controls. The frequencies of heterozygosity for HLA-DRB1*04:01/*15 (P = 1.88 × 10-7, OR 81.54, 95% CI 4.74‒1402.63) and DRB1*09:01/*15 (P = 0.0061, OR 2.94, 95% CI 1.38‒6.25) were also higher in MCTD patients. Haplotype and logistic regression analyses suggested a predisposing role for HLA-DRB1*04:01, DQB1*03:03, and a protective role for DRB1*13:02. Increased frequencies of HLA-DRB1*04:01/*15 and DRB1*09:01/*15 heterozygous genotypes were found in Japanese MCTD patients.

Detection of SARS-CoV-2 Nucleocapsid, Spike, and Neutralizing Antibodies in Vaccinated Japanese.

Serological detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N), spike (S), and neutralizing antibodies (Abs) is commonly undertaken to evaluate the efficacy of vaccination. However, the relative efficiency of different SARS-CoV-2 Ab detection systems has not been extensively investigated. Here, we evaluated serological test systems in vaccinated Japanese. SARS-CoV-2 N, S, and neutralizing Abs in sera of 375 healthy subjects a mean 253 days after vaccination were assessed. The sensitivity of Elecsys Anti-SARS-CoV-2 S (Roche S) and Anti-SARS-CoV-2 S IgG (Fujirebio S) was 100% and 98.9%, respectively, with a specificity of 100% for both. The sensitivity of Anti-SARS-CoV-2 neutralizing Ab (MBL Neu) was 2.7%, and the specificity was 100%. Fujirebio S correlated with Roche S (rho = 0.9182, p = 3.97 × 10-152). Fujirebio S (rho = 0.1295, p = 0.0121) and Roche S (rho = 0.1232, p = 0.0170) correlated weakly with MBL Neu. However, Roche S did correlate with MBL Neu in patients with COVID-19 (rho = 0.8299, p = 1.01 × 10-12) and in healthy subjects more recently after vaccination (mean of 90 days, rho = 0.5306, p = 0.0003). Thus, the Fujirebio S and Roche S results were very similar, but neither correlated with neutralizing antibody titers by MBL Neu at a later time after vaccination.

Lack of Association of rs12702634 in RPA3-UMAD1 With Interstitial Lung Diseases in Japanese Rheumatoid Arthritis Patients.

Background: Rheumatoid arthritis (RA) is occasionally complicated with interstitial lung disease (ILD). A recent genome-wide association study of ILD in RA reported an association with the polymorphism rs12702634 in RPA3-UMAD1. We conducted an association study of this variant with ILD in Japanese RA patients to replicate this association. Methods: Genotyping of rs12702634 was performed in 175 RA with ILD and 411 RA without chronic lung disease. Results: No association was detected for rs12702634 with ILD in RA (P = .6369, odds ratio [OR] 1.13, 95% confidence interval [CI] 0.72-1.78). Meta-analysis of these data combined with the data from the recent report showed no significant association (P = .0996, OR 1.52, 95% CI 0.92-2.49). Conclusions: The present study demonstrated no association of RPA3-UMAD1 rs12702634 with ILD in RA, suggesting the heterogeneity of the disease.

Detection of Anti-SARS-CoV-2 Nucleocapsid and Spike Antibodies in Patients with Coronavirus Disease 2019 in Japan.

OBJECTIVES: Coronavirus Disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Serological testing for anti-SARS-CoV-2 nucleocapsid (N) antibodies (Abs) and anti-SARS-CoV-2 spike (S) Abs is performed to detect prior COVID-19 infection. It is still controversial which antibodies are the most sensitive and specific, and which can be detected earliest after infection. Here, we evaluated the results of serological tests of anti-SARS-CoV-2 N and S Abs in Japan. METHODS: Symptomatic COVID-19 patients (n = 84) and control patients with rheumatoid arthritis (n = 93) were recruited at Tokyo National Hospital. Anti-SARS-CoV-2 N and S Abs were measured by commercial electrochemiluminescence immunoassays. RESULTS: The fraction of patients positive for anti-SARS-CoV-2 N and S Abs was highest >14 days after symptom onset. The frequency of anti-SARS-CoV-2 S Ab positivity at this time (80.4%) tended to be slightly but not significantly lower than anti-SARS-CoV-2 N Ab positivity (84.8%). Optimized cut-off levels for anti-SARS-CoV-2 N and S Ab positivity were lower than the manufacturer's recommended cut-off levels. Using multiple linear regression analyzes with anti-SARS-CoV-2 N and S Abs, we created an Ab-index with high sensitivity. CONCLUSION: To increase the sensitivity of serological diagnostic tests for COVID-19, it is suggested that both anti-SARS-CoV-2 N and S Abs should be measured and cut-off levels decreased.

Evaluation of cytokine levels in response to mitogen among HIV-1-infected blood cells and their relationships to the number of T cells.

BACKGROUND: Human immunodeficiency virus-1 (HIV-1) infection causes loss and anergy of CD4+ and CD8+ T cells, leading to opportunistic infections, including tuberculosis (TB). QuantiFERON®-TB (QFT) is used as a diagnostic tool to detect TB, but it exhibits limited accuracy among subjects with low CD4+ T cell numbers, including HIV-1-infected individuals. The present study aimed to determine the effect of HIV-1 infection and patients' blood T cell numbers on cytokine production in response to mitogen (Mit) stimulation. METHODS: The number of CD4+ and CD8+ T cells in HIV-1-infected individuals was quantified. Levels of various cytokines in Mit-stimulated and un-stimulated (Nil) supernatants of QFT gold "in tube" were assessed using a MAGPIX System. The correlation between cytokine levels and CD4+/CD8+ T cell counts in response to Mit was analyzed. The cytokine levels were compared between HIV-1-infected and healthy subjects. RESULTS: HIV-1-infected individuals (110) and control subjects (27) were enrolled. Interferon (IFN)-γ, interleukin-1 receptor antagonist (IL-1RA), IL-6, IL-8, and regulated on activation, normal T cell expressed and secreted (RANTES) values in Mit-Nil tubes showed a significant correlation with CD4+ T cell counts, while IFN-γ, IL-6, and IFN-γ-induced protein 10 (IP-10) values in Mit-Nil tubes had significant correlation with CD8+ T cell counts. IL-1RA, IL-8, IP-10, platelet-derived growth factor (PDGF)-BB, and RANTES levels in Nil tubes were significantly higher in the HIV-1-infected group. IFN-γ, IL-2, IL-5, IL-6, IP-10, and macrophage inflammatory protein-1ß values in Mit-Nil tubes were significantly higher, and PDGF-BB and RANTES levels were significantly lower in the HIV-1-infected group. CONCLUSION: The functions of HIV-1-infected T cells and uninfected T cells, such as spontaneous and responsive cytokine production in response to Mit, were different. Our findings may be useful for developing new clinical tools for patients with low T cell counts. Additionally, the study provides new insights into the pathogenesis of HIV-1 infection.

Distal Interphalangeal Joint Involvement May Be Associated with Disease Activity and Affected Joint Distribution in Rheumatoid Arthritis.

We investigated the relationship between distal interphalangeal (DIP) joint involvement and disease activity in 10,038 patients with adult-onset rheumatoid arthritis (RA). The affected joint distribution was investigated using the joint indices (JI) x, y, and z, corresponding to the upper and lower joints, and the predominance of large-joint involvement, respectively. DIP joint involvement (defined by the presence of tenderness and/or swelling in DIP joints) was present in 206 (2.1%) of 10,038 patients with RA. Patients with RA exhibiting DIP joint involvement were significantly younger, and more frequently women. DIP joint involvement was positively associated with Disease Activity Score-28 using C-reactive protein, and clinical variables related to high RA disease activity, including JIs x and y, and was negatively associated with JI z. JI x was significantly higher than JI y in RA patients with DIP joint involvement. An odds ratio analysis revealed that small-to-medium sized and upper-extremity joints ranked first, second, and fourth among the eight variables significantly associated with DIP joint involvement. The correlation coefficients revealed that small-sized and upper-extremity joints ranked first and second among the five significant variables. DIP joint involvement, albeit rare, is significantly associated with high RA disease activity with predominance of small-sized and upper-extremity joints.