Mucosal-associated invariant T cell deficiency in systemic lupus erythematosus.

Mucosal-associated invariant T (MAIT) cells contribute to protection against certain microorganism infections and play an important role in mucosal immunity. However, the role of MAIT cells remains enigmatic in autoimmune diseases. In this study, we examined the level and function of MAIT cells in patients with rheumatic diseases. MAIT cell, cytokine, and programmed death-1 (PD-1) levels were measured by flow cytometry. Circulating MAIT cell levels were significantly reduced in systemic lupus erythematosus (SLE) and rheumatoid arthritis patients. In particular, this MAIT cell deficiency was more prominent in CD8(+) and double-negative T cell subsets, and significantly correlated with disease activity, such as SLE disease activity index and 28-joint disease activity score. Interestingly, MAIT cell frequency was significantly correlated with NKT cell frequency in SLE patients. IFN-γ production in MAIT cells was impaired in SLE patients, which was due to an intrinsic defect in the Ca(2+)/calcineurin/NFAT1 signaling pathway. In SLE patients, MAIT cells were poorly activated by α-galactosylceramide-stimulated NKT cells, thereby showing the dysfunction between MAIT cells and NKT cells. Notably, an elevated expression of PD-1 in MAIT cells and NKT cells was associated with SLE. In rheumatoid arthritis patients, MAIT cell levels were significantly higher in synovial fluid than in peripheral blood. Our study primarily demonstrates that MAIT cells are numerically and functionally deficient in SLE. In addition, we report a novel finding that this MAIT cell deficiency is associated with NKT cell deficiency and elevated PD-1 expression. These abnormalities possibly contribute to dysregulated mucosal immunity in SLE.

Analysis of predictors influencing indeterminate whole-blood interferon-gamma release assay results in patients with rheumatic diseases.

Triggers of indeterminate results from interferon-gamma release assays (IGRA) in patients with rheumatic diseases are still elusive. The aim of the present study was to describe predictors of indeterminate results from IGRA in the field of rheumatology. This cross-sectional study was retrospectively performed by using a database of patients with a request for QuantiFERON-TB Gold-In Tube test (QFT-GIT) for screening of latent tuberculosis infection. The study cohort included 631 patients with rheumatic diseases. All variables influencing indeterminate QFT-GIT results were investigated by logistic regression analysis. The overall frequency of indeterminate IGRA results was 6.8 % (43/631). Those with indeterminate results were more likely to be aged ≥70 years, female, visitors in winter, suffering from systemic lupus erythematosus (SLE), and using sulfasalazine or a tumor necrosis factor (TNF)-α inhibitor. In addition, a longer incubation time of >6 h increased the odds ratio of indeterminate IGRA results. In contrast, the automated ELISA processor, ankylosing spondylitis, and the use of a non-steroidal anti-inflammatory drug decreased the likelihood of indeterminate IGRA results. Lymphopenia, thrombocytopenia, anemia, and hypoalbuminemia were significantly associated with indeterminate IGRA results. Multivariate analysis revealed that SLE, use of sulfasalazine or a TNF-α inhibitor, and a manual ELISA system were significantly independent predictors of indeterminate IGRA results. The proportion of indeterminate results in patients with rheumatic diseases is not infrequent. Careful attention to the pre-analytical conditions should minimize the indeterminate results. Automation of the ELISA process seems to be a promising solution to decrease the rate of indeterminate response.

Circulating mucosal-associated invariant T cell levels and their cytokine levels in healthy adults.

Mucosal-associated invariant T (MAIT) cells have been reported to play an antimicrobial role in infectious diseases. However, little is known about age- and gender-related changes in circulating MAIT cell level and function in healthy population. The purposes of this study were to examine the level and cytokine production of circulating MAIT cells and their subsets in healthy adults and to investigate potential relationships between clinical parameters and MAIT cell levels or their subset levels. One hundred thirty-three healthy subjects were enrolled in this study. MAIT cells, their subset, and cytokine levels were measured by flow cytometry. Circulating MAIT cell levels were found to vary widely (0.19% to 21.7%) in the study subjects and to be significantly lower in elderly subjects (age, 61-92 years) than in young subjects (age, 21-40 years) (p<0.0005). No significant difference was found in the circulating MAIT cell levels between male and female subjects. A linear regression analysis revealed that circulating MAIT cell levels declined annually by 3.2% among men and 1.8% among women, respectively. Notably, the proportion of CD4+ MAIT cells increased with age, whereas that of CD8+ MAIT cells decreased with age. In addition, the production of interleukin (IL)-4 by MAIT cells was found to be significantly increased in elderly subjects and the ratio of interferon (IFN)-γ/IL-4 was lower as compared with young subjects, showing a Th1 to Th2 shift in cytokine profile in elderly subjects. Our data suggest that aging is associated with a reduction in circulating MAIT cells, accompanied with alterations in subset composition and cytokine profile.

Association study of the candidate gene for knee osteoarthritis in Koreans.

The aim of this study was to examine a single-nucleotide polymorphism (SNP) rs7639618 of double von Willebrand factor (DVWA) gene for the association with osteoarthritis (OA) susceptibility in Korean cohort. The study was a part of the Korean cohort study. Two thousand four hundred sixty-two subjects aged 50 years and older who were derived from the cohort and who were assessed for OA at the knee were genotyped. The anteroposterior extended-view weight-bearing radiographs of the knees were obtained. Of the subjects, 725 subjects had radiographic OA. Genomic DNA was extracted from peripheral blood using a QIAamp DNA Blood Mini Kit (Qiagen, Valencia, CA). Genotyping was performed using High Resolution Melt or the Taq-Man allelic discrimination assay and the Rotor-Gene 6000 (Corbett Research, Sydney,Australia). Associations were tested by calculating the odds ratios (ORs) and 95% confidence intervals (95% CIs), using logistic regression analysis with adjustments for age, gender, and body mass index (BMI). The mean age of the OA patients (females: 554 subjects, 76.4%) was 67.4 (7.9) years. The intraobserver agreement was high for the identification of osteophytes (κ: 0.80) and joint space narrowing (κ: 0.70). There was no significant difference (all P values > 0.05) in the genotype or allele frequencies between the patients with OA and healthy controls. There was also no significant difference when the cases were adjusted by age, gender, and BMI. The associations of DVWA SNPs with OA were noted in previous studies and were not found in the Korean OA cohort.

Age- and gender-related differences in circulating natural killer T cells and their subset levels in healthy Korean adults.

Natural killer T (NKT) cells have been reported to play crucial roles in a variety of diseases, including infectious diseases, autoimmunity, and cancers. Previous studies have reported wide age- and/or sex-related variations in circulating NKT cell levels in healthy subjects, but reported results are discrepant. In this study, the authors examined NKT cell levels in the peripheral blood of healthy Korean subjects and investigated potential relationships between clinical parameters and NKT cells and their subset levels. One hundred and thirty-eight age- and sex-matched healthy subjects were enrolled in this study. NKT cell and NKT subset levels were measured by flow cytometry. Circulating NKT cell levels were found to vary widely (0.01-5.15%) in the study subjects and to be lower in men than in women (P<0.05). Notably, gender-related differences in NKT cell levels were more prominent in elderly subjects (P<0.05). Furthermore, alterations in NKT subset compositions were found in elderly men, in whom the proportion of CD4+ NKT cells was elevated and that of double-negative NKT cells was reduced. Our data suggest that circulating NKT cells and NKT subset levels are affected by age and gender in the Korean population.

Natural killer T cell deficiency in active adult-onset Still's Disease: correlation of deficiency of natural killer T cells with dysfunction of natural killer cells.

OBJECTIVE: To examine the levels and functions of natural killer (NK) and natural killer T (NKT) cells, investigate relationships between NK and NKT cells, and determine the clinical relevance of NKT cell levels in patients with adult-onset Still's disease (AOSD). METHODS: Patients with active untreated AOSD (n = 20) and age- and sex-matched healthy controls (n = 20) were studied. NK and NKT cell levels were measured by flow cytometry. Peripheral blood mononuclear cells were cultured in vitro with α-galactosylceramide (αGalCer). NK cytotoxicity against K562 cells and proliferation indices of NKT cells were estimated by flow cytometry. RESULTS: Percentages and absolute numbers of NKT cells were significantly lower in the peripheral blood of AOSD patients than in that of healthy controls. Proliferative responses of NKT cells to αGalCer were also lower in patients, and this was found to be due to proinflammatory cytokines and NKT cell apoptosis. In addition, NK cytotoxicity was found to be significantly lower in patients than in healthy controls, but NK cell levels were comparable in the 2 groups. Notably, this NKT cell deficiency was found to be correlated with NK cell dysfunction and to reflect active disease status. Furthermore, αGalCer-mediated NK cytotoxicity, showing the interaction between NK and NKT cells, was significantly lower in AOSD patients than in healthy controls. CONCLUSION: These findings demonstrate that NK and NKT cell functions are defective in AOSD patients and suggest that these abnormalities contribute to innate immune dysfunction in AOSD.

Immune cells and bone formation in ankylosing spondylitis.

OBJECTIVES: The aims of this study were to examine immune cell proportions in peripheral blood of patients with ankylosing spondylitis (AS) and to investigate relationships between immune cells, level of bone formation related molecules, and radiographic changes. METHODS: Forty-nine AS patients and 53 age- and sex-matched healthy controls (HCs) were enrolled in this study. Clinical parameters were extensively evaluated in the study subjects. CD4+ T-cells, CD8+ T-cells, CD56+ T-cells, natural killer cells, and natural killer T (NKT) cells in peripheral blood were measured by flow cytometry. Serum levels of Dickkopf-1 and bone morphogenic proteins were determined using enzyme linked immunosorbent assays. Modified Stokes AS spinal scores were used to assess radiographic changes. RESULTS: Patients were found to have a significantly higher percentages of CD56+T-cells than healthy controls (median 1.31% vs. 0.53%, p<0.001), whereas percentages of peripheral blood natural killer T (NKT) cell were lower in patients than in controls (median 0.07 % vs. 0.10%, p=0.010). Moreover, mean CD 56+T to NKT cell ratio was markedly higher in patients. Although no significant correlations were observed between the immune cell percentages and bone formation-related molecule levels, interestingly, patients with a higher CD56+T to NKT cell ratio at baseline were found to develop greater radiographic changes (r=0.79, p=0.007, age and disease duration adjusted) during 3 years of radiographic follow-up. CONCLUSIONS: An altered T-cell compartment, particularly with respect to CD56+ T and NKT cells, was observed in AS patients and could contribute to radiographic changes in AS.

Dysfunction of natural killer T cells in patients with active Mycobacterium tuberculosis infection.

Natural killer T (NKT) cells are known to play a protective role in the immune responses of mice against a variety of infectious pathogens. However, little is known about the detailed information of NKT cells in patients with Mycobacterium tuberculosis infection. The aims of this study were to examine NKT cell levels and functions in patients with active M. tuberculosis infection, to investigate relationships between NKT cell levels and clinical parameters, and to determine the mechanism responsible for the poor response to α-galactosylceramide (α-GalCer). NKT cell levels were significantly lower in the peripheral blood of pulmonary tuberculosis and extrapulmonary tuberculosis patients, and the proliferative responses of NKT cells to α-GalCer were also lower in patients, whereas NKT cell levels and responses were comparable in latent tuberculosis infection subjects and healthy controls. Furthermore, this NKT cell deficiency was found to be correlated with serum C-reactive protein levels. In addition, the poor response to α-GalCer in M. tuberculosis-infected patients was found to be due to increased NKT cell apoptosis, reduced CD1d expression, and a defect in NKT cells. Notably, M. tuberculosis infection was associated with an elevated expression of the inhibitory programmed death-1 (PD-1) receptor on NKT cells, and blockade of PD-1 signaling enhanced the response to α-GalCer. This study shows that NKT cell levels and functions are reduced in M. tuberculosis-infected patients and these deficiencies were found to reflect the presence of active tuberculosis.

Detection of HTLV-1 in the labial salivary glands of patients with Sjögren's syndrome: a distinct clinical subgroup?

OBJECTIVE: To examine whether patients with Sjögren's syndrome (SS) can be distinguished based on the expression of human T cell lymphotrophic virus type I (HTLV-1) and, if so, whether the subgroups differ in their clinical features and serological measures. METHODS: Polymerase chain reaction (PCR) and nested PCR were used to amplify viral DNA from peripheral blood mononuclear cells (PBMC) in 53 patients with SS, using primers from the HTLV-1 pX, p19, pol, and tax regions. Minor salivary gland biopsy specimens from 33 patients with SS were examined for the presence of HTLV-1 p19 or tax proteins immunohistochemically. The sociodemographic, glandular, and extraglandular manifestations, and laboratory findings including autoantibodies, complement, and immunoglobulin levels, were analyzed. RESULTS: The HTLV-1 tax gene was detected in PBMC samples from 2 of 53 patients (3.8%), whereas the HTLV-1 pX, p19, and pol genes were not expressed. As well, 100% of PBMC samples from 4 family members of patients in whom the tax gene was detected also expressed the tax gene. Immunohistochemical staining for HTLV-1 p19 and tax was seen in 10 out of 33 (30.3%) patients with SS each. Overall, 14 (42.4%) patients expressed HTLV-1 p19 or tax proteins, and they had lower rheumatoid factor and C3 levels (p = 0.015 and p = 0.005, respectively) and higher lymphocyte counts (p = 0.016). The prevalence of glandular and extraglandular manifestations did not differ between the HTLV-1-positive and negative patients. CONCLUSION: Our findings suggest that HTLV-1 in the salivary glands is involved in the pathogenesis of a subpopulation of SS, and HTLV-1-associated SS might have different immunological patterns than idiopathic SS.

Genetic association analysis of GDF5 and ADAM12 for knee osteoarthritis.

OBJECTIVES: To examine two single-nucleotide polymorphisms (SNPs) for their association with knee osteoarthritis (OA) susceptibility in Korean cohort. METHODS: Two thousand four hundred and sixty-two subjects aged 50 years and older were assessed for OA at the knee, were genotyped with two SNPs (GDF5; rs143383 and ADAM12; rs3740199). Radiographs were read by two examiners that used an atlas of radiographic features to obtain a global Kellgren/Lawrence (K/L) score. Genomic DNA was extracted from peripheral blood using a QIAamp DNA Blood Mini Kit. GDF5 genotyping was performed by high resolution melting analysis. ADAM12 genotyping was performed by TaqMan assay. The allele frequencies were assessed by counting alleles. Associations were tested by calculating the odds ratios (ORs) and 95% confidence intervals (95% CIs), using logistic regression analysis with adjustments for age, gender and body mass index (BMI). RESULTS: Of this cohort, 725 subjects had radiographic OA (defined as a K/L score of ≥ 2). The mean age of the OA patients (females: 76.4%) was 67.4 (7.9) years. In GDF5, we observed a T-allele frequency of 74.1% in our controls, compared with that of 73.7% in patients (P = 0.72; OR 0.97, 95% CI; 0.83-1.13). In ADAM12, the frequency of G-allele in the case (54.6%) versus the control (55.0%) was calculated (P = 0.94, OR 1.01, 95% CI; 0.88-1.15). There was no significant difference in the genotype frequencies between the patients and healthy controls. CONCLUSION: The associations of two SNPs with OA that were noted in previous studies, were not found in the Korean OA cohort.

Bone destruction by receptor activator of nuclear factor κB ligand-expressing T cells in chronic gouty arthritis.

INTRODUCTION: The purpose of this study was to analyze the cellular expressions of pro-resorptive cytokines in gouty tophus tissues, to determine the capacity of monosodium urate monohydrate (MSU) crystals to induce these cytokines, and to understand the mechanisms of bone destruction in chronic gout. METHODS: Fourteen fixed, paraffin-embedded, uninfected tophus samples were analyzed immunohistochemically. Peripheral blood mononuclear cells (PBMCs) were cultured in vitro with MSU crystals, and gene expression was assessed by reverse transcription-polymerase chain reaction. In vitro osteoclastogenesis was performed using PBMCs and synovial fluid mononuclear cells (SFMCs). RESULTS: CD4+ T cells, CD8+ T cells, CD20+ B cells and mast cells infiltrated tophus tissues. Tartrate-resistant acid phosphatase (TRAP)+ osteoclasts were present around tophi and in osteolytic lesions. Interleukin (IL)-1, IL-6 and tumor necrosis factor (TNF)-alpha were produced from infiltrated mononuclear cells, whereas receptor activator of nuclear factor κB ligand (RANKL) was strongly expressed in T cells. However, osteoprotegerin (OPG) was not or was weakly expressed in tophus tissues. MSU crystals induced the expressions of IL-1, IL-6, TNF-alpha and RANKL in PBMCs, but inhibited OPG expression. In addition, the pro-resorptive cytokines were highly expressed in SFMCs of gouty arthritis patients. Furthermore, in vitro osteoclastogenesis was enhanced in SFMC cultures, but inhibited in T cell-depleted SFMC cultures. CONCLUSIONS: Our study demonstrates that RANKL-expressing T cells and TRAP+ osteoclasts are present within gouty tophus tissues, and that infiltrating cells express pro-resorptive cytokines. Furthermore, our data show that MSU crystals have the potential to induce pro-resorptive cytokines, and T cells are involved in osteoclastogenesis in chronic gout.

Numerical and functional deficiencies of natural killer T cells in systemic lupus erythematosus: their deficiency related to disease activity.

OBJECTIVE: This study was designed to examine the frequency of natural killer T (NKT) cells and the response to α-galactosylceramide (α-GalCer) in SLE patients and to investigate the clinical relevance of NKT cell levels. METHODS: Patients with SLE (n = 128) and age- and sex-matched healthy controls (HCs) (n = 92) were enrolled in the study. NKT cell and CD1d levels were measured by flow cytometry. Gene expression was determined by RT-PCR, and cytokine secretion by multiple cytokine assay. Peripheral blood mononuclear cells (PBMCs) were cultured in vitro with α-GalCer. Proliferation indices of NKT cells were estimated by flow cytometry. RESULTS: Percentages and absolute numbers of NKT cells were significantly lower in the peripheral blood of SLE patients than in that of HCs, whereas CD1d levels in PBMCs were comparable between these two groups. Notably, this NKT cell deficiency was found to be correlated with SLEDAI. NKT cell proliferation was found to be impaired in SLE patients, and cytokine production by NKT cells in response to α-GalCer was diminished. This poor responsiveness to α-GalCer was found to be due to NKT cell dysfunction rather than to an abnormality in CD1d-expressing cells. CONCLUSIONS: Our data show that NKT cell levels and functions are defective in SLE patients. Furthermore, these deficiencies were found to reflect disease activity. It would appear that these NKT cell abnormalities could contribute to immune system dysregulation in SLE.

Development of antisynthetase syndrome in a patient with rheumatoid arthritis.

Rheumatoid arthritis (RA) and antisynthetase syndrome (ASS) are distinct clinical syndromes, and their co-occurrence is rarely encountered. The authors report the case of a 56-year-old female patient with RA of 3 years duration who suddenly developed ASS, and include a review of the literature. The patient was diagnosed with ASS based on; positivity for anti-histidyl-tRNA synthetase (Jo-1) antibody, interstitial lung disease, polyarthritis, and mechanic's hands. High-dose corticosteroid and pulse intravenous cyclophosphamide were used to control the ASS. This case demonstrates that ASS should be considered during clinical presentations due to its potential overlap with RA.

Phase II study of S-1 monotherapy in paclitaxel- and cisplatin-refractory gastric cancer.

PURPOSE: S-1 is a fourth-generation oral fluoropyrimidine that was developed to mimic the effects achieved with protracted continuous infusion of 5-fluorouracil (5-FU). This phase II study evaluated the efficacy and safety of S-1 salvage chemotherapy in patients with paclitaxel- and cisplatin-refractory gastric cancer. The primary end point was progression-free survival; secondary end points were overall survival, safety, and clinical benefit. METHODS: Patients were eligible for the study if they had histologically documented gastric adenocarcinoma previously treated with paclitaxel and cisplatin, age > or = 18 years, Eastern Clinical Oncology Group performance status < or =2, adequate organ function, and no evidence of gastrointestinal obstruction or passage disturbance. Patients were treated with a dose of S-1 based on body surface area (BSA) as follows: BSA < 1.25 m(2), 80 mg/day; 1.25 < or = BSA < 1.5 m(2), 100 mg/day; BSA > or= 1.5 m(2), 120 mg/day. The total dose was divided in two and administered twice daily for 4 weeks followed by a 2-week rest period. RESULTS: Of the 53 patients enrolled in this study, 49 were evaluable. A total of 190 chemotherapy cycles were administered, and the median number of cycles was 2. Five patients (9.4%) had a partial response, and 18 (34%) had stable disease. Median progression-free survival and overall survival were 4.9 and 10.4 months, respectively. Grade 3/4 hematological toxicities included neutropenia in six patients (11%) but no cases of febrile neutropenia were found. Most of the non-hematological toxicities were diarrhea, asthenia, and mucositis, but none reached grade 3 or grade 4 in severity. Improvement of pain was observed in 17 patients (32.1%). CONCLUSIONS: S-1 monotherapy provides active and safe salvage chemotherapy for patients with advanced gastric cancer who have been previously treated with paclitaxel and cisplatin.

Dermatomyositis associated with hepatitis B virus-related hepatocellular carcinoma.

Dermatomyositis (DM) is an idiopathic inflammatory myopathy (IIM) with typical cutaneous manifestations. It has been proposed that DM may be caused by autoimmune responses to viral infections, and previous studies have also shown that an association between DM and malignancy. However, chronic hepatitis B virus (HBV) infection associated with DM and hepatocellular carcinoma (HCC) is rarely encountered. The authors report a case of DM and HCC in a patient with a HBV infection. A 58-year-old man presented erythematous skin rashes on a sun-exposed area of 2 year's duration, and recent proximal muscle weakness. His medical history revealed that he had a chronic HBV infection. A diagnosis of DM relies on proximal muscle weakness, elevated muscle enzymes, myopathic changes (demonstrated by electromyography), muscle biopsy evidence of myositis, and its characteristic cutaneous findings. A Liver mass in the left lobe visualized by abdominal computed tomography was confirmed histologically as HCC. This case suggests that DM associated with HCC might be caused by a HBV infection.