Adopting the International Consensus on ANA Patterns (ICAP) classification for reporting: the experience of Italian clinical laboratories

The indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) is still considered the reference method to detect anti-nuclear antibodies (ANA) because of its high sensitivity and represents a relevant tool for the diagnosis of autoimmune rheumatic diseases. During the last decade, the International Consensus on ANA Patterns (ICAP) initiative promoted harmonization and understanding of HEp-2 IFA staining pattern nomenclature, as well as promoting their use in patient care by providing interpretation for HEp-2 IFA test results. In conjunction with a nationwide survey on the evolution of autoantibody diagnostics in autoimmune rheumatic diseases, we focused on the adherence of the Italian laboratories to the ICAP nomenclature analyzing its lights and shadows. The recent ICAP-oriented report, largely used today among Italian laboratories, also represents a further step in harmonizing and improving communication with the clinicians, adding value to laboratory findings and helping with critical clinical decisions.

Unique miRomics Expression Profiles in Tannerella forsythia-Infected Mandibles during Periodontitis Using Machine Learning

T. forsythia is a subgingival periodontal bacterium constituting the subgingival pathogenic polymicrobial milieu during periodontitis (PD). miRNAs play a pivotal role in maintaining periodontal tissue homeostasis at the transcriptional, post-transcriptional, and epigenetic levels. The aim of this study was to characterize the global microRNAs (miRNA, miR) expression kinetics in 8- and 16-week-old T. forsythia-infected C57BL/6J mouse mandibles and to identify the miRNA bacterial biomarkers of disease process at specific time points. We examined the differential expression (DE) of miRNAs in mouse mandibles (n = 10) using high-throughput NanoString nCounter® miRNA expression panels, which provided significant advantages over specific candidate miRNA or pathway analyses. All the T. forsythia-infected mice at two specific time points showed bacterial colonization (100%) in the gingival surface, along with a significant increase in alveolar bone resorption (ABR) (p < 0.0001). We performed a NanoString analysis of specific miRNA signatures, miRNA target pathways, and gene network analysis. A total of 115 miRNAs were DE in the mandible tissue during 8 and 16 weeks The T. forsythia infection, compared with sham infection, and the majority (99) of DE miRNAs were downregulated. nCounter miRNA expression kinetics identified 67 downregulated miRNAs (e.g., miR-375, miR-200c, miR-200b, miR-34b-5p, miR-141) during an 8-week infection, whereas 16 upregulated miRNAs (e.g., miR-1902, miR-let-7c, miR-146a) and 32 downregulated miRNAs (e.g., miR-2135, miR-720, miR-376c) were identified during a 16-week infection. Two miRNAs, miR-375 and miR-200c, were highly downregulated with >twofold change during an 8-week infection. Six miRNAs in the 8-week infection (miR-200b, miR-141, miR-205, miR-423-3p, miR-141-3p, miR-34a-5p) and two miRNAs in the 16-week infection (miR-27a-3p, miR-15a-5p) that were downregulated have also been reported in the gingival tissue and saliva of periodontitis patients. This preclinical in vivo study identified T. forsythia-specific miRNAs (miR-let-7c, miR-210, miR-146a, miR-423-5p, miR-24, miR-218, miR-26b, miR-23a-3p) and these miRs have also been reported in the gingival tissues and saliva of periodontitis patients. Further, several DE miRNAs that are significantly upregulated (e.g., miR-101b, miR-218, miR-127, miR-24) are also associated with many systemic diseases such as atherosclerosis, Alzheimer's disease, rheumatoid arthritis, osteoarthritis, diabetes, obesity, and several cancers. In addition to DE analysis, we utilized the XGBoost (eXtreme Gradient boost) and Random Forest machine learning (ML) algorithms to assess the impact that the number of miRNA copies has on predicting whether a mouse is infected. XGBoost found that miR-339-5p was most predictive for mice infection at 16 weeks. miR-592-5p was most predictive for mice infection at 8 weeks and also when the 8-week and 16-week results were grouped together. Random Forest predicted miR-592 as most predictive at 8 weeks as well as the combined 8-week and 16-week results, but miR-423-5p was most predictive at 16 weeks. In conclusion, the expression levels of miR-375 and miR-200c family differed significantly during disease process, and these miRNAs establishes a link between T. forsythia and development of periodontitis genesis, offering new insights regarding the pathobiology of this bacterium.

Oral Spirochete Treponema denticola Intraoral Infection Reveals Unique miR-133a, miR-486, miR-126-3p, miR-126-5p miRNA Expression Kinetics during Periodontitis

miRNAs are major regulators of eukaryotic gene expression and host immunity, and play an important role in the inflammation-mediated pathways in periodontal disease (PD) pathogenesis. Expanding our previous observation with the global miRNA profiling using partial human mouth microbes, and lack of in vivo studies involving oral spirochete Treponema denticola-induced miRNAs, this study was designed to delineate the global miRNA expression kinetics during progression of periodontitis in mice infected with T. denticola by using NanoString nCounter® miRNA panels. All of the T. denticola-infected male and female mice at 8 and 16 weeks demonstrated bacterial colonization (100%) on the gingival surface, and an increase in alveolar bone resorption (p < 0.0001). A total of 70 miRNAs with at least 1.0-fold differential expression/regulation (DE) (26 upregulated and 44 downregulated) were identified. nCounter miRNA expression profiling identified 13 upregulated miRNAs (e.g., miR-133a, miR-378) and 25 downregulated miRNAs (e.g., miR-375, miR-34b-5p) in T. denticola-infected mouse mandibles during 8 weeks of infection, whereas 13 upregulated miRNAs (e.g., miR-486, miR-126-5p) and 19 downregulated miRNAs (miR-2135, miR-142-3p) were observed during 16 weeks of infection. One miRNA (miR-126-5p) showed significant difference between 8 and 16 weeks of infection. Interestingly, miR-126-5p has been presented as a potential biomarker in patients with periodontitis and coronary artery disease. Among the upregulated miRNAs, miR-486, miR-126-3p, miR-126-5p, miR-378a-3p, miR-22-3p, miR-151a-3p, miR-423-5p, and miR-221 were reported in human gingival plaques and saliva samples from periodontitis and with diabetes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed various functional pathways of DE miRNAs, such as bacterial invasion of epithelial cells, Ras signaling, Fc gamma R-mediated phagocytosis, osteoclast differentiation, adherens signaling, and ubiquitin mediated proteolysis. This is the first study of DE miRNAs in mouse mandibles at different time-points of T. denticola infection; the combination of three specific miRNAs, miR-486, miR-126-3p, and miR-126-5p, may serve as an invasive biomarker of T. denticola in PD. These miRNAs may have a significant role in PD pathogenesis, and this research establishes a link between miRNA, periodontitis, and systemic diseases.

Analytical aspects of the antinuclear antibody test by HEp-2 indirect immunofluorescence: EFLM report on an international survey

OBJECTIVES

Detection of antinuclear antibodies (ANA) by indirect immunofluorescence assay using HEp-2 cells (HEp-2 IFA) is used to screen for various autoimmune diseases. HEp-2 IFA suffers from variability, which hampers harmonization.

METHODS

A questionnaire was developed to collect information on HEp-2 IFA methodology, computer-assisted diagnosis (CAD) systems, training, inter-observer variability, quality assessment, reagent lot change control, and method verification. The questionnaire was distributed to laboratories by Sciensano (Belgium), national EASI groups (Italy, Croatia, Portugal, Estonia, Greece) and ICAP (worldwide). Answers were obtained by 414 laboratories. The results were analysed in the framework of the recent EFLM/EASI/ICAP ANA recommendations (companion paper).

RESULTS

Laboratories used either HEp-2, HEp-2000, or HEp-20-10 cells and most laboratories (80%) applied the same screening dilution for children and adults. The conjugate used varied between laboratories [IgG-specific (in 57% of laboratories) vs. polyvalent]. Sixty-nine percent of CAD users reviewed the automatic nuclear pattern and 53% of CAD users did not fully exploit the fluorescence intensity for quality assurance. Internal quality control was performed by 96% of the laboratories, in 52% of the laboratories only with strongly positive samples. Interobserver variation was controlled by 79% of the laboratories. Limited lot-to-lot evaluation was performed by 68% of the laboratories. Method verification was done by 80% of the respondents.

CONCLUSIONS

Even though many laboratories embrace high-quality HEp-2 IFA, substantial differences in how HEp-2 IFA is performed and controlled remain. Acting according to the EFLM/EASI/ICAP ANA recommendations can improve the global performance and quality of HEp-2 IFA and nurture harmonization.

Detection of antinuclear antibodies: recommendations from EFLM, EASI and ICAP

OBJECTIVES

Antinuclear antibodies (ANA) are important for the diagnosis of various autoimmune diseases. ANA are usually detected by indirect immunofluorescence assay (IFA) using HEp-2 cells (HEp-2 IFA). There are many variables influencing HEp-2 IFA results, such as subjective visual reading, serum screening dilution, substrate manufacturing, microscope components and conjugate. Newer developments on ANA testing that offer novel features adopted by some clinical laboratories include automated computer-assisted diagnosis (CAD) systems and solid phase assays (SPA).

METHODS

A group of experts reviewed current literature and established recommendations on methodological aspects of ANA testing. This process was supported by a two round Delphi exercise. International expert groups that participated in this initiative included (i) the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group "Autoimmunity Testing"; (ii) the European Autoimmune Standardization Initiative (EASI); and (iii) the International Consensus on ANA Patterns (ICAP).

RESULTS

In total, 35 recommendations/statements related to (i) ANA testing and reporting by HEp-2 IFA; (ii) HEp-2 IFA methodological aspects including substrate/conjugate selection and the application of CAD systems; (iii) quality assurance; (iv) HEp-2 IFA validation/verification approaches and (v) SPA were formulated. Globally, 95% of all submitted scores in the final Delphi round were above 6 (moderately agree, agree or strongly agree) and 85% above 7 (agree and strongly agree), indicating strong international support for the proposed recommendations.

CONCLUSIONS

These recommendations are an important step to achieve high quality ANA testing.

Anti-dense fine speckled 70 (DFS70) autoantibodies: correlates and increasing prevalence in the United States

Objective

Recent studies report high-titer anti-dense fine speckled 70 (DFS70) autoantibodies in persons with inflammatory conditions, but the clinical significance remains unclear. Our goals were to estimate anti-DFS70 autoantibody prevalence, identify correlates, and assess time trends.

Methods

Serum antinuclear antibodies (ANA) were measured by indirect immunofluorescence assay on HEp-2 cells in 13,519 participants ≥12 years old from three time periods (1988-1991, 1999-2004, 2011-2012) of the National Health and Nutrition Examination Survey. ANA-positive participants with dense fine speckled staining were evaluated for anti-DFS70 antibodies by enzyme-linked immunosorbent assay. We used logistic models adjusted for survey-design variables to estimate period-specific anti-DFS70 antibody prevalence in the US, and we further adjusted for sex, age, and race/ethnicity to identify correlates and assess time trends.

Results

Women were more likely than men (odds ratio (OR)=2.97), black persons were less likely than white persons (OR=0.60), and active smokers were less likely than nonsmokers (OR=0.28) to have anti-DFS70 antibodies. The prevalence of anti-DFS70 antibodies increased from 1.6% in 1988-1991 to 2.5% in 1999-2004 to 4.0% in 2011-2012, which corresponds to 3.2 million, 5.8 million, and 10.4 million seropositive individuals, respectively. This increasing time trend in the US population (P<0.0001) was modified in some subgroups and was not explained by concurrent changes in tobacco smoke exposure. Some, but not all, anti-DFS70 antibody correlates and time trends resembled those reported for total ANA.

Conclusion

More research is needed to elucidate anti-DFS70 antibody triggers, their pathologic or potentially protective influences on disease, and their possible clinical implications.

Specific microRNA Signature Kinetics in Porphyromonas gingivalis-Induced Periodontitis

Porphyromonas gingivalis is one of the major bacteria constituting the subgingival pathogenic polymicrobial milieu during periodontitis. Our objective is to determine the global microRNA (miRNA, miR) expression kinetics in 8- and 16-weeks duration of P. gingivalis infection in C57BL/6J mice and to identify the miRNA signatures at specific time-points in mice. We evaluated differential expression (DE) miRNAs in mandibles (n = 10) using high-throughput NanoString nCounter® miRNA expression panels. The bacterial colonization, alveolar bone resorption (ABR), serum immunoglobulin G (IgG) antibodies, and bacterial dissemination were confirmed. In addition, all the infected mice showed bacterial colonization on the gingival surface, significant increases in ABR (p < 0.0001), and specific IgG antibody responses (p < 0.05-0.001). The miRNA profiling showed 26 upregulated miRNAs (e.g., miR-804, miR-690) and 14 downregulated miRNAs (e.g., miR-1902, miR-1937a) during an 8-weeks infection, whereas 7 upregulated miRNAs (e.g., miR-145, miR-195) and one downregulated miR-302b were identified during a 16-weeks infection. Both miR-103 and miR-30d were commonly upregulated at both time-points, and all the DE miRNAs were unique to the specific time-points. However, miR-31, miR-125b, miR-15a, and miR-195 observed in P. gingivalis-infected mouse mandibles were also identified in the gingival tissues of periodontitis patients. None of the previously identified miRNAs reported in in vitro studies using cell lines (periodontal ligament cells, gingival epithelial cells, human leukemia monocytic cell line (THP-1), and B cells) exposed to P. gingivalis lipopolysaccharide were observed in the in vivo study. Most of the pathways (endocytosis, bacterial invasion, and FcR-mediated phagocytosis) targeted by the DE miRNAs were linked with bacterial pathogen recognition and clearance. Further, eighteen miRNAs were closely associated with the bacterial invasion of epithelial cells. This study highlights the altered expression of miRNA in gingiva, and their expression depends on the time-points of infection. This is the first in vivo study that identified specific signature miRNAs (miR-103 and miR-30d) in P. gingivalis invasion of epithelial cells, establishes a link between miRNA and development of periodontitis and helping to better understand the pathobiology of periodontitis.

Anti-Ro52 Autoantibody Is Common in Systemic Autoimmune Rheumatic Diseases and Correlating with Worse Outcome when Associated with interstitial lung disease in Systemic Sclerosis and Autoimmune Myositis

This review highlights the 30 plus years research progress since the discovery of autoantibody to Ro52/TRIM21 in patients with systemic lupus erythematosus (SLE) and Sjögren's syndrome (SjS). After the initial expression cloning of the Ro52 cDNA, it has taken many years to the current understanding in the interesting biological function of Ro52 as an E3 ubiquitin ligase and its role in innate immune clearance of intracellular IgG-bound complex. Early observations show that anti-Ro52, mostly associated with anti-SS-A/Ro60 and/or anti-SS-B/La, is commonly found in SLE (40-70%), SjS (70-90%), neonatal lupus erythematosus (NLE, 75-90%), and subacute cutaneous lupus erythematosus (50-60%). Anti-Ro52 has long been postulated to play a direct pathogenic role in congenital heart block in NLE as well as in the QT interval prolongation in some adults. The widespread availability of the anti-Ro52 assay has led to the detection of anti-Ro52 in other diseases including autoimmune hepatitis (20-40%), systemic sclerosis (10-30%), and autoimmune myositis (20-40%). More than ten studies have pointed to an association of anti-Ro52 with interstitial lung disease and, more importantly, correlating with poor outcome and worse survival. Other studies are implicating an interesting role for anti-Ro52 in the diagnosis of certain cancers. Future studies are needed to examine the mechanism in the pathogenesis of anti-Ro52 and carefully documenting its causal relationships in different disease conditions.

Fusobacterium is enriched in oral cancer and promotes induction of programmed death-ligand 1 (PD-L1)

Recently, increased number of studies have demonstrated a relationship between the oral microbiome and development of head and neck cancer, however, there are few studies to investigate the role of oral bacteria in the context of the tumor microenvironment in a single head and neck subsite. Here, paired tumor and adjacent normal tissues from thirty-seven oral tongue squamous cell carcinoma (SCC) patients were subjected to 16S rRNA gene sequencing and whole exome sequencing (WES), in addition to RNA sequencing for tumor samples. We observed that Fusobacterium was significantly enriched in oral tongue cancer and that Rothia and Streptococcus were enriched in adjacent normal tissues. A decrease in alpha diversity was found in tumor when compared to adjacent normal tissues. While increased Fusobacterium in tumor samples was not associated with changes in immune cell infiltration, it was associated with increased PD-L1 mRNA expression. Therefore, we examined the effects of Fusobacterium on PD-L1 expression in head and neck SCC cell lines. We demonstrated that infection with Fusobacterium species can increase both PD-L1 mRNA and surface PD-L1 protein expression on head and neck cancer cell lines. The correlation between Fusobacterium and PD-L1 expression in oral tongue SCC, in conjunction with the ability of the bacterium to induce PD-L1 expression in vitro suggests a potential role for Fusobacterium on modulation of the tumor immune microenvironment in head and neck cancer.

Expanded assessment of xenobiotic associations with antinuclear antibodies in the United States, 1988-2012

BACKGROUND

The prevalence of autoimmunity in the U.S. has increased recently for undetermined reasons. Little is known about associations between autoimmunity and environmental causes.

OBJECTIVES

In a large representative sample of the U.S. population, we expanded our prior exploratory study of how exposures to selected xenobiotics and dioxin-like (DL) mixtures relate to antinuclear antibodies (ANA), the most common biomarker of autoimmunity.

METHODS

We analyzed cross-sectional data on 12,058 participants aged ≥ 12 years from three time periods of the National Health and Nutrition Examination Survey between 1988 and 2012, of whom 14% were ANA-positive. We used lognormal regression models and censored-data methods to estimate ANA associations with xenobiotic concentrations overall and in sex, age, and race/ethnicity subgroups. Our analyses adjusted for potential confounders and appropriately handled concentrations below detection limits.

RESULTS

Observed ANA associations were positive for most DL compounds and nonDL polychlorinated biphenyls (PCBs), negative for most phthalates, and mixed for other xenobiotic classes. After correcting for multiple comparisons, some associations remained statistically significant. In subgroup analyses, the most significant finding was a positive ANA association with N-acetyl-S-(2-hydroxy-3-butenyl)-L-cysteine (MHB2) in males, followed by positive associations with 2,2',3,5'-tetrachlorobiphenyl (PCB 44), 2,2',4,5'-tetrachlorobiphenyl (PCB 49), and 2,2',3,4',5',6-hexachlorobiphenyl (PCB 149) in 12-19 year-olds, and with 3,4,4',5-tetrachlorobiphenyl (PCB 81), 2,2',3,3',4,4',5,5',6-nonachlorobiphenyl (PCB 206), and N-acetyl-S-(phenyl)-L-cysteine (PMA) in Mexican Americans. Negative associations were found with mono-benzyl phthalate (MBzP) in 20-49 year-olds and mono-n-butyl phthalate (MnBP) in 12-19 year-olds. In overall analyses, combining stratum-specific results across race/ethnicity strata revealed a positive ANA association with PCB 81 and a negative ANA association with N-acetyl-S-(2-hydroxyethyl)-L-cysteine (HEMA).

DISCUSSION

This study identified potential associations between ANA and various xenobiotics. Further investigation to confirm these observations and elucidate effects of certain xenobiotics on immune regulation could have important mechanistic, preventive, and treatment implications for a variety of immune-mediated disorders.

The International Consensus on ANA Patterns (ICAP) in 2021-The 6th Workshop and Current Perspectives

The establishment of the International Consensus on ANA Patterns (ICAP) in 2014-2015 was welcomed by members of the medical community as a significant improvement in guiding harmonization of ANA test interpretation and reporting. In the subsequent years, several itinerant meetings and continuous interaction with the community contributed to disseminate the ICAP harmonization on the immunofluorescence patterns observed in the indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) and to promote progressive improvement in the classification of HEp-2 IFA patterns. The 6th ICAP Workshop was held in person on September 6, 2021 as a satellite meeting of the 15th Dresden Symposium on Autoantibodies. This article summarizes the major discussions at the meeting as well as outlining the current plans for the ICAP committee.

Strong Association of the Myriad Discrete Speckled Nuclear Pattern With Anti-SS-A/Ro60 Antibodies: Consensus Experience of Four International Expert Centers

Introduction

The morphological patterns in indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) reflect the autoantibodies in the sample. The International Consensus on ANA Patterns (ICAP) classifies 30 relevant patterns (AC-0 to AC-29). AC-4 (fine speckled nuclear pattern) is associated to anti-SS-A/Ro, anti-SS-B/La, and several autoantibodies. Anti-SS-A/Ro samples may contain antibodies to Ro60 and Ro52. A variation of AC-4 (herein designated AC-4a), characterized by myriad discrete nuclear speckles, was reported to be associated with anti-SS-A/Ro. The plain fine speckled pattern (herein designated AC-4b) seldom was associated with anti-SS-A/Ro. This study reports the experience of four expert laboratories on AC-4a and AC-4b.

Methods

Anti-Ro60 monoclonal antibody A7 was used to investigate the HEp-2 IFA pattern. Records containing concomitant HEp-2 IFA and SS-A/Ro tests from Durand Laboratory, Argentina (n = 383) and Fleury Laboratory, Brazil (n = 144,471) were analyzed for associations between HEp-2 IFA patterns and disease-associated autoantibodies (DAA): double-stranded DNA, Scl-70, nucleosome, SS-B/La, Sm, and U1-RNP. A total of 381 samples from Dresden Technical University (TU-Dresden), Germany, were assayed for HEp-2 IFA and DAA.

Results

Monoclonal A7 recognized Ro60 in Western blot and immunoprecipitation, and yielded the AC-4a pattern on HEp-2 IFA. Analyses from Durand Laboratory and Fleury Laboratory yielded compatible results: AC-4a was less frequent (8.9% and 2.7%, respectively) than AC-4b (26.1% and 24.2%) in HEp-2 IFA-positive samples. Reactivity to SS-A/Ro occurred in 67.6% and 96.3% of AC-4a-pattern samples against 23% and 6.8% of AC-4b pattern samples. Reciprocally, AC-4a occurred in 24% and 47.1% of anti-SS-A/Ro-positive samples, and in 3.8% and 0.1% of anti-SS-A/Ro-negative samples. Data from TU-Dresden show that the AC-4a pattern occurred in 69% of 169 anti-SS-A/Ro-monospecific samples (62% of all anti-SS-A/Ro-positive samples) and in 4% of anti-SS-A/Ro-negative samples, whereas anti-SS-A/Ro occurred in 98.3% of AC-4a samples and in 47.9% of AC-4b samples. In all laboratories, coexistence of anti-SS-B/La, but not other DAA, in anti-SS-A/Ro-positive samples did not disturb the AC-4a pattern. AC-4a was predominantly associated with anti-Ro60 antibodies.

Conclusions

This study confirms the association of AC-4a pattern and anti-SS-A/Ro in opposition to the AC-4b pattern. The results of four international expert laboratories support the worldwide applicability of these AC-4 pattern variants and their incorporation into ICAP classification under codes AC-4a and AC-4b, respectively. The AC-4 pattern should be maintained as an umbrella pattern for cases in which one cannot discriminate AC-4a and AC-4b patterns. The acknowledgment of the AC-4a pattern should add value to HEp-2 IFA interpretation.

How to report the antinuclear antibodies (anti-cell antibodies) test on HEp-2 cells: guidelines from the ICAP initiative

Results of the anti-nuclear antibodies-indirect immunofluorescence assay (anti-cell antibodies test) on HEp-2 cell substrates should be communicated to clinicians in a standardized way, adding value to laboratory findings and helping with critical clinical decisions. This paper proposes a test report based on the practices informed by 118 laboratories in 68 countries, with recommendations from the International Consensus on ANA Patterns (ICAP) group. Major focus is placed on the report format containing endpoint titers, immunofluorescence patterns together with anti-cell (AC) nomenclature, remarks on follow-up or reflex testing, and possible other autoantibody associations. ISO 15,189 directives were integrated into the test report. Special situations addressed include serum screening dilutions and endpoint titers, relevance of immunofluorescence patterns with special attention to cytoplasmic patterns, mixed and compound patterns, and how to report different titers corresponding to multiple patterns or autoantibodies in the same sample. This paper suggests a subtitle for the HEp-2-IIFA, namely anti-cell antibodies test, which could gradually substitute the original outdated ANA nomenclature. This ICAP pro forma report represents a further step in harmonizing the way relevant clinical information could be provided by laboratories.

Subgingival microbiome of deep and shallow periodontal sites in patients with rheumatoid arthritis: a pilot study

Background

Subgingival microbiome in disease-associated subgingival sites is known to be dysbiotic and significantly altered. In patients with rheumatoid arthritis (RA), the extent of dysbiosis in disease- and health-associated subgingival sites is not clear.

Methods

8 RA and 10 non-RA subjects were recruited for this pilot study. All subjects received full oral examination and underwent collection of subgingival plaque samples from both shallow (periodontal health-associated, probing depth ≤ 3mm) and deep subgingival sites (periodontal disease-associated, probing depth ≥ 4 mm). RA subjects also had rheumatological evaluation. Plaque community profiles were analyzed using 16 S rRNA sequencing.

Results

The phylogenetic diversity of microbial communities in both RA and non-RA controls was significantly higher in deep subgingival sites compared to shallow sites (p = 0.022), and the overall subgingival microbiome clustered primarily according to probing depth (i.e. shallow versus deep sites), and not separated by RA status. While a large number of differentially abundant taxa and gene functions was observed between deep and shallow sites as expected in non-RA controls, we found very few differentially abundant taxa and gene functions between deep and shallow sites in RA subjects. In addition, compared to non-RA controls, the UniFrac distances between deep and shallow sites in RA subjects were smaller, suggesting increased similarity between deep and shallow subgingival microbiome in RA. Streptococcus parasanguinis and Actinomyces meyeri were overabundant in RA subjects, while Gemella morbillorum, Kingella denitrificans, Prevotella melaninogenica and Leptotrichia spp. were more abundant in non-RA subjects.

Conclusions

The aggregate subgingival microbiome was not significantly different between individuals with and without rheumatoid arthritis. Although the differences in the overall subgingival microbiome was driven primarily by probing depth, in contrast to the substantial microbiome differences typically seen between deep and shallow sites in non-RA patients, the microbiome of deep and shallow sites in RA patients were more similar to each other. These results suggest that factors associated with RA may modulate the ecology of subgingival microbiome and its relationship to periodontal disease, the basis of which remains unknown but warrants further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01597-x.

The antinuclear antibody HEp-2 indirect immunofluorescence assay: a survey of laboratory performance, pattern recognition and interpretation

Background

To evaluate the interpretation and reporting of antinuclear antibodies (ANA) by indirect immunofluorescence assay (IFA) using HEp-2 substrates based on common practice and guidance by the International Consensus on ANA patterns (ICAP).

Method

Participants included two groups [16 clinical laboratories (CL) and 8 in vitro diagnostic manufacturers (IVD)] recruited via an email sent to the Association of Medical Laboratory Immunologists (AMLI) membership. Twelve (n = 12) pre-qualified specimens were distributed to participants for testing, interpretation and reporting HEp-2 IFA. Results obtained were analyzed for accuracy with the intended and consensus response for three main categorical patterns (nuclear, cytoplasmic and mitotic), common patterns and ICAP report nomenclatures. The distributions of antibody titers of specimens were also compared.

Results

Laboratories differed in the categorical patterns reported; 8 reporting all patterns, 3 reporting only nuclear patterns and 5 reporting nuclear patterns with various combinations of other patterns. For all participants, accuracy with the intended response for the categorical nuclear pattern was excellent at 99% [95% confidence interval (CI): 97–100%] compared to 78% [95% CI 67–88%] for the cytoplasmic, and 93% [95% CI 86%–100%] for mitotic patterns. The accuracy was 13% greater for the common nomenclature [87%, 95% CI 82–90%] compared to the ICAP nomenclature [74%, 95% CI 68–79%] for all participants. Participants reporting all three main categories demonstrated better performances compared to those reporting 2 or less categorical patterns. The average accuracies varied between participant groups, however, with the lowest and most variable performances for cytoplasmic pattern specimens. The reported titers for all specimens varied, with the least variability for nuclear patterns and most titer variability associated with cytoplasmic patterns.

Conclusions

Our study demonstrated significant accuracy for all participants in identifying the categorical nuclear staining as well as traditional pattern assignments for nuclear patterns. However, there was less consistency in reporting cytoplasmic and mitotic patterns, with implications for assigning competencies and training for clinical laboratory personnel.

Fusobacteria modulate oral carcinogenesis and promote cancer progression

Background: Evidence suggest periodontal bacterial infection can contribute to oral cancer initiation and progression.

Aim: To investigate the effects of periodontal bacteria on oral cancer cell behavior using a cell-based system and a mouse carcinogenesis model.

Methods: Oral cancer cell lines were polyinfected with four periodontal bacteria. Cytokine levels and relative changes in oncogene mRNA expression were determined post-infection. Oral tumours in mice induced by 4-nitroquinoline-1-oxide (4NQO) were compared with and without administrating periodontal bacteria.

Results: Polyinfected oral cancer cells had upregulated MMP1, MMP9, and IL-8. The expression of cell survival markers MYC, JAK1, and STAT3 and epithelial-mesenchymal transition markers ZEB1 and TGF-β were also significantly elevated. Monoinfections showed F. nucleatum alone had comparable or greater effects than the four bacteria together. Fusobacterial culture supernatant, primarily LPS, was sufficient to induce IL-8 secretion, demonstrating that direct contact of live Fusobacteria with cancer cells might not be required to exert changes in cancer cell behaviour. In the 4NQO-induced oral tumour model, mice infected with bacteria developed significantly larger and more numerous lesions compared to those not infected.

Conclusion: This study demonstrated that Fusobacteria could potentially enhance cancer cell invasiveness, survival, and EMT when presented in the oral tumour microenvironment.

Abbreviations: 4NQO, 4-nitroquinoline-1-oxide; ELISA, enzyme-linked immunosorbent assay; EMT, epithelial–mesenchymal transition; IL-8, interleukin-8; JAK1, Janus kinase 1; LPS, lipopolysaccharide; MMP, matrix metalloproteinase; OSCCs, oral squamous cell carcinomas; PK, proteinase K; PMB, Polymyxin B; qRT-PCR, quantitative real-time polymerase chain reaction; STAT3, signal transducer and activator of transcription 3; TGF-β, transforming growth factor beta; ZEB1, zinc finger E-Box binding homeobox 1

Current laboratory and clinical practices in reporting and interpreting anti-nuclear antibody indirect immunofluorescence (ANA IIF) patterns: results of an international survey

Background

The International Consensus on Antinuclear Antibody (ANA) Patterns (ICAP) has recently proposed nomenclature in order to harmonize ANA indirect immunofluorescence (IIF) pattern reporting. ICAP distinguishes competent-level from expert-level patterns. A survey was organized to evaluate reporting, familiarity, and considered clinical value of ANA IIF patterns.

Methods

Two surveys were distributed by European Autoimmunity Standardization Initiative (EASI) working groups, the International Consensus on ANA Patterns (ICAP) and UK NEQAS to laboratory professionals and clinicians.

Results

438 laboratory professionals and 248 clinicians from 67 countries responded. Except for dense fine speckled (DFS), the nuclear competent patterns were reported by > 85% of the laboratories. Except for rods and rings, the cytoplasmic competent patterns were reported by > 72% of laboratories.

Cytoplasmic IIF staining was considered ANA positive by 55% of clinicians and 62% of laboratory professionals, with geographical and expertise-related differences.

Quantification of fluorescence intensity was considered clinically relevant for nuclear patterns, but less so for cytoplasmic and mitotic patterns. Combining IIF with specific extractable nuclear antigens (ENA)/dsDNA antibody testing was considered most informative.

Of the nuclear competent patterns, the centromere and homogeneous pattern obtained the highest scores for clinical relevance and the DFS pattern the lowest. Of the cytoplasmic patterns, the reticular/mitochondria-like pattern obtained the highest scores for clinical relevance and the polar/Golgi-like and rods and rings patterns the lowest.

Conclusion

This survey confirms that the major nuclear and cytoplasmic ANA IIF patterns are considered clinically important. There is no unanimity on classifying DFS, rods and rings and polar/Golgi-like as a competent pattern and on reporting cytoplasmic patterns as ANA IIF positive.

Anti-DFS70 Antibodies Among Patient and Healthy Population Cohorts in China: Results From a Multicenter Training Program Showing Spontaneous Abortion and Pediatric Systemic Autoimmune Rheumatic Diseases Are Common in Anti-DFS70 Positive Patients

Objective

Anti-DFS70 antibodies correlating with the nuclear dense fine speckled (DFS) pattern in the HEp-2 indirect immunofluorescence assay (IFA) are less common in patients with systemic autoimmune rheumatic disease (SARD) than in healthy subjects and their clinical associations remain elusive. We hosted a multi-center HEp-2 IFA training program to improve the ability of clinical laboratories to recognize the DFS pattern and to investigate the prevalence and relevance of anti-DFS70 antibodies.

Methods

DFS pattern sera identified by HEp-2 IFA in 29 centers in China were redirected to a central laboratory for anti-DFS70 testing by line immunoblot assay (LIA), enzyme-linked immunosorbent assay (ELISA), and IFA with HEp-2 ELITE/DFS70-KO substrate. Anti-extractable nuclear antigen antibodies were measured by LIA and the clinical relevance was examined in adult and pediatric patients.

Results

HEp-2 IFA positive rate and DFS pattern in positive sera were 36.2% (34,417/95,131) and 1.7% (582/34,417) in the patient cohort, and 10.0% (423/4,234) and 7.8% (33/423) in a healthy population, respectively. Anti-DFS70 prevalence among sera presenting the DFS pattern was 96.0, 93.7, and 49.6% by ELISA, LIA, and HEp-2 ELITE, respectively. 15.5% (52/336) of adult and 50.0% (20/40) of pediatric anti-DFS70 positive patients were diagnosed with SARD. Diseases most common in anti-DFS70 positive patients were spontaneous abortion (28.0%) in adults and juvenile idiopathic arthritis (22.5%) in pediatric patients.

Conclusion

Accurate DFS pattern identification increased the detection rate of anti-DFS70 antibodies by ELISA and LIA. Anti-DFS70 antibodies are remarkably high in cases of spontaneous abortion and in pediatric SARD patients, but not prevalent in adult SARD patients.

Anti-rods/rings autoantibody and IMPDH filaments: an update after fifteen years of discovery

Autoantibodies to unknown subcellular rod and ring-shaped structures were first discovered in sera from hepatitis C patients in 2005. Early studies showed a strong association between these anti-rods/rings antibodies (anti-RR) and the standard of care interferon-α plus ribavirin combination therapy (IFN/RBV), suggesting that anti-RR are drug-induced autoantibodies. In the context of hepatitis C, anti-RR have been linked with relapse from or lack of response to IFN/RBV in some patient cohorts. However, examples of anti-RR in other diseases and healthy individuals have also been reported over the years, although anti-RR remains a rare autoantibody response in general. The advent of new direct-acting antiviral drugs for chronic hepatitis C and studies of anti-RR from different parts of the world are also beginning to change the perception of anti-RR. The nucleotide biosynthetic enzyme inosine monophosphate dehydrogenase (IMPDH) has been identified as the major autoantigen recognized by anti-RR. Coincidentally, the assembly of IMPDH into micron-scale rod and ring-shaped structures was discovered around the same time as anti-RR. Knowledge of the fundamental biological properties and cellular functions of these structures, referred to as "IMPDH filaments" by cell biologists, has advanced in parallel to anti-RR antibodies. Recent studies have revealed that IMPDH filament assembly is a mechanism to prevent feedback inhibition of IMPDH and is therefore important for the increased nucleotide production required in hyperproliferating cells, like activated T cells. Fifteen years later, we review the history and current knowledge in both the anti-RR autoantibody and IMPDH filament fields. TAKE-HOME MESSAGE: Anti-rods/rings are recognized as an example of a drug-induced autoantibody in hepatitis C patients treated with interferon and ribavirin, although new studies suggest anti-rods/rings may be detected in other contexts and may depend on unknown environmental or genetic factors in different populations. Recent data suggest that the assembly of IMPDH into rod and ring structures, the targets of anti-rods/rings autoantibody, is a mechanism for hyperproliferating cells, like activated T cells, to maintain increased guanine nucleotide levels to support rapid cell division.

Establishment of international autoantibody reference standards for the detection of autoantibodies directed against PML bodies, GW bodies, and NuMA protein

Objectives:

Reference materials are important in the standardization of autoantibody testing and only a few are freely available for many known autoantibodies. Our goal was to develop three reference materials for antibodies to PML bodies/multiple nuclear dots (MND), antibodies to GW bodies (GWB), and antibodies to the nuclear mitotic apparatus (NuMA).

Methods:

Reference materials for identifying autoantibodies to MND (MND-REF), GWB (GWB-REF), and NuMA (NuMA-REF) were obtained from three donors and validated independently by seven laboratories. The sera were characterized using indirect immunofluorescence assay (IFA) on HEp-2 cell substrates including two-color immunofluorescence using antigen-specific markers, western blot (WB), immunoprecipitation (IP), line immunoassay (LIA), addressable laser bead immunoassay (ALBIA), enzyme-linked immunosorbent assay (ELISA), and immunoprecipitation–mass spectrometry (IP-MS).

Results:

MND-REF stained 6–20 discrete nuclear dots that colocalized with PML bodies. Antibodies to Sp100 and PML were detected by LIA and antibodies to Sp100 were also detected by ELISA. GWB-REF stained discrete cytoplasmic dots in interphase cells, which were confirmed to be GWB using two-color immunofluorescence. Anti-Ge-1 antibodies were identified in GWB-REF by ALBIA, IP, and IP-MS. All reference materials produced patterns at dilutions of 1:160 or greater. NuMA-REF produced fine speckled nuclear staining in interphase cells and staining of spindle fibers and spindle poles. The presence of antibodies to NuMA was verified by IP, WB, ALBIA, and IP-MS.

Conclusions:

MND-REF, GWB-REF, and NuMA-REF are suitable reference materials for the corresponding antinuclear antibodies staining patterns and will be accessible to qualified laboratories.

Increasing Prevalence of Antinuclear Antibodies in the United States

OBJECTIVE

Growing evidence suggests increasing frequencies of autoimmunity and certain autoimmune diseases, but findings are limited by the lack of systematic data and evolving approaches and definitions. This study was undertaken to investigate whether the prevalence of antinuclear antibodies (ANA), the most common biomarker of autoimmunity, changed over a recent 25-year span in the US.

METHODS

Serum ANA were measured by standard indirect immunofluorescence assays on HEp-2 cells in 14,211 participants age ≥12 years from the National Health and Nutrition Examination Survey, with approximately one-third from each of 3 time periods: 1988-1991, 1999-2004, and 2011-2012. We used logistic regression adjusted for sex, age, race/ethnicity, and survey design variables to estimate changes in ANA prevalence across the time periods.

RESULTS

The prevalence of ANA was 11.0% (95% confidence interval [95% CI] 9.7-12.6%) in 1988-1991, 11.5% (95% CI 10.3-12.8%) in 1999-2004, and 15.9% (95% CI 14.3-17.6%) in 2011-2012 (P for trend < 0.0001), which corresponds to ~22 million, ~27 million, and ~41 million affected individuals, respectively. Among adolescents age 12-19 years, ANA prevalence increased substantially, with odds ratios (ORs) of 2.02 (95% CI 1.16-3.53) and 2.88 (95% CI 1.64-5.04) in the second and third time periods relative to the first (P for trend < 0.0001). ANA prevalence increased in both sexes (especially in men), older adults (age ≥50 years), and non-Hispanic whites. These increases in ANA prevalence were not explained by concurrent trends in weight (obesity/overweight), smoking exposure, or alcohol consumption.

CONCLUSION

The prevalence of ANA in the US has increased considerably in recent years. Additional studies to determine factors underlying these increases in ANA prevalence could elucidate causes of autoimmunity and enable the development of preventative measures.

Abstract A10: Fusobacteria upregulates PD-L1 in head and neck cancer cell lines: Potential mechanism for immune evasion

Objectives: Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide with a poor prognosis of ~40% at 5 years for HPV-negative disease. Recently, immune checkpoint inhibitors (specifically, anti-PD-1 checkpoint inhibitors that block the PD-L1/PD-1 immunosuppressive axis) have been approved as a treatment for patients with recurrent/metastatic HNSCC. However, most patients (&gt;80%) fail to respond to checkpoint inhibitors. PD-L1 expression on tumors plays an important role in immune evasion and can also influence response to checkpoint inhibitors. Tumor PD-L1 expression has been shown to correlate with checkpoint response. Factors that might affect PDL1 expression in HNSCC remain unclear. In this study, we explored the effect of periodontal bacteria, which has been associated with oral cancer, on PD-L1 expression in oral cancer cells.

Materials and Methods: 303 HNSCC were compared to 37 adjacent control tissues in the TCGA mRNA expression database (RNASeq V2); the analysis was done based on tumor types. RT-PCR and flow cytometry were used to measure the base line expression of PD-L1 in seven head and neck cancer cell lines and human oral tissues. OQ01, an oral cancer cell line, was infected with four periodontal bacteria (Tanneralla forsynthia, Treponema denticola, Porphyromonas gingivalis, and Fusobacterium nucleatum). OQ01 and RPMI2650 cells were infected with two different strains of Fusobacteria (F. periodonticum, F. vincentii). The relative changes in expression of PLD1 was measured using RT-PCR in cell lysate after RNA isolation. PD-L1 protein level on the cell surface was measured using flow cytometry.

Results: TCGA data analysis revealed that PDL1 was significantly (P&lt; 0.0005) elevated in total cancer tissues compared to total controls. In the same data analysis, PDL1 expression was significantly (P&lt; 0.05) elevated in oral cavity tumor compared to normal control. Expression of PD-L1 was variable among head and neck cancer patients and cell lines. Both F. nucleatum and P. gingivalis were able to enhance PD-L1 expression in OQ01 cells (10 and 15 fold, respectively). Two strains of Fusobacteria tested (F. periodonticum, F. vincentii) were also able to induce PD-L1 both at the mRNA (P&lt; 0.005 and P&lt; 0.05 respectively) and protein level in OQ01 and RPMI 2650 cells. Interestingly, the same strains of Fusobacteria enhanced MYC expression in OQ01 and RPMI 2650 cells. As a transcription factor MYC has been reported to regulate PDL1 transcription. These data along with our results suggest that Fusobacterial upregulation of PD-L1 expression might be through MYC enhanced expression.

Conclusions: This study revealed that Fusobacteria enhance PD-L1 expression on HNSCC cancer cell lines, possibly through upregulation of MYC. This may have implications on cancer cell immune evasion and checkpoint inhibitor treatment response.

Note: This abstract was not presented at the conference.

Citation Format: Amani Harrandah, Rekha Rani Grag, Yuk Pheel Park, Sasanka S. Chukkapalli, Nikhita Yadlapalli, Edward K. L. Chan, Natalie Silver. Fusobacteria upregulates PD-L1 in head and neck cancer cell lines: Potential mechanism for immune evasion [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr A10.

Reference standards for the detection of anti-mitochondrial and anti-rods/rings autoantibodies

Background:

Anti-mitochondrial antibodies (AMA) are found in >90% of primary biliary cholangitis patients. Anti-rods/rings antibodies (anti-RR) are most commonly associated with interferon-α and ribavirin treatment in hepatitis C patients. Clinical laboratories routinely screen for AMA and anti-RR using indirect immunofluorescence on HEp-2 cells (HEp-2-IFA). Therefore, we sought to establish reference materials for use in AMA and anti-RR testing.

Methods:

AMA-positive and anti-RR-positive human plasma samples (AMA-REF and RR-REF), identified as potential reference materials based on preliminary data, were further validated by multiple laboratories using HEp-2-IFA, immunoprecipitation (IP), western blotting, IP-western, line immunoassay (LIA), addressable laser bead immunoassay (ALBIA) and enzyme-linked immunosorbent assay (ELISA).

Results:

AMA-REF showed a strong positive cytoplasmic reticular/AMA staining pattern by HEp-2-IFA to ≥1:1280 dilution and positive signal on rodent kidney/stomach/liver tissue. AMA-REF reacted with E2/E3, E3BP, E1α and E1β subunits of the pyruvate dehydrogenase complex by IP and western blotting and was positive for AMA antigens by LIA, ALBIA and ELISA. RR-REF showed a strong positive rods and rings staining pattern by HEp-2-IFA to ≥1:1280 dilution. RR-REF reacted with inosine monophosphate dehydrogenase by IP, IP-western and ALBIA. RR-REF also produced a nuclear homogenous staining pattern by HEp-2-IFA, immunoprecipitated proteins associated with anti-U1RNP antibody and reacted weakly with histones, nucleosomes, Sm and nRNP/Sm by LIA.

Conclusions:

AMA-REF and RR-REF are useful reference materials for academic or commercial clinical laboratories to calibrate and establish internal reference standards for immunodiagnostic assays. AMA-REF and RR-REF are now available for free distribution to qualified laboratories through Plasma Services Group.

Ribavirin induces widespread accumulation of IMP dehydrogenase into rods/rings structures in multiple major mouse organs

Ribavirin (RBV) is a guanosine analogue triazole most commonly used in the treatment of chronic hepatitis C (HCV) infection. Although its mechanism of action is a matter of debate, several possibilities have been proposed, including depletion of guanine nucleotides through inhibition of inosine monophosphate dehydrogenase (IMPDH). IMPDH has been shown to assemble into micron-scale rod- and ring-shaped structures (rods/rings or RR), also called "IMPDH filaments," both in vitro and in vivo. Formation of RR structures can occur naturally, potentially to influence IMPDH activity, or when de novo guanosine monophosphate biosynthesis or IMPDH itself are inhibited by nutrient deprivation or drugs like RBV. Numerous studies have also reported the occurrence of autoantibodies targeting RR structures (anti-RR) in HCV patients previously treated or under treatment with interferon-α and ribavirin (IFN/RBV) combination therapy. For this brief study, we considered the strong association between RR autoantibodies and IFN/RBV treatment, and the lack of data assessing how RBV affects RR formation in a variety of tissues in vivo. First, RR structures formed in the spleen and pancreas of normal mice without any treatment. Then, in RBV-treated mice, we detected RR structures in a number of tissues, including stomach, liver, spleen, kidney, brain, skin, and cardiac and skeletal muscle. We made several intriguing observations: predominance of RR structures in the mucosa and submucosa layers of the stomach wall; a high proportion of RR-positive cells in the cerebral cortex, suggesting that RBV actually crosses the blood-brain barrier; and a higher ratio of rings to rods in the epidermis compared to the dermis layer of the skin. Screening for RR structures appears to be a useful method to track tissue penetration of RBV and the many RR-inducing drugs previously identified.

Immune Response-Dependent Assembly of IMP Dehydrogenase Filaments

Inosine monophosphate dehydrogenase (IMPDH) catalyzes the conversion of IMP to xanthosine monophosphate, the rate-limiting step in de novo guanosine monophosphate (GMP) synthesis. In cultured cells, IMPDH polymerizes into micron-scale filamentous structures when GMP synthesis is inhibited by depletion of purine precursors or by various drugs, including mycophenolic acid, ribavirin, and methotrexate. IMPDH filaments also spontaneously form in undifferentiated mouse embryonic stem cells and induced pluripotent stem cells, hinting they might function in various highly proliferative cell types. Therefore, we investigated IMPDH filament formation in human and murine T cells, which rely heavily on de novo guanine nucleotide synthesis to rapidly proliferate in response to antigenic challenge. We discovered extensive in vivo IMPDH filament formation in mature T cells, B cells, and other proliferating splenocytes of normal, adult B6 mice. Both cortical and medullary thymocytes in young and old mice also showed considerable assembly of IMPDH filaments. We then stimulated primary human peripheral blood mononuclear cells ex vivo with T cell mitogens phytohemagglutinin (PHA), concanavalin A (ConA), or antibodies to CD3 and CD28 for 72 h. We detected IMPDH filaments in 40–60% of T cells after activation compared to 0–10% of unstimulated T cells. Staining of activated T cells for the proliferation marker Ki-67 also showed an association between IMPDH filament formation and proliferation. Additionally, we transferred ovalbumin-specific CD4⁺ T cells from B6.OT-II mice into B6.Ly5a recipient mice, challenged these mice with ovalbumin, and harvested spleens 6 days later. In these spleens, we identified abundant IMPDH filaments in transferred T cells by immunofluorescence, indicating that IMPDH also polymerizes during in vivo antigen-specific T cell activation. Overall, our data indicate that IMPDH filament formation is a novel aspect of T cell activation and proliferation, and that filaments might be useful morphological markers for T cell activation. The data also suggest that in vivo IMPDH filament formation could be occurring in a variety of proliferating cell types throughout the body. We propose that T cell activation will be a valuable model for future experiments probing the molecular mechanisms that drive IMPDH polymerization, as well as how IMPDH filament formation affects cell function.

Prescription medication use and antinuclear antibodies in the United States, 1999-2004

BACKGROUND

Clinical reports link specific medications with the development of antinuclear antibodies (ANA), but population-based evidence is limited.

OBJECTIVE

The present study investigated associations between prescription medication use and ANA in a representative sample of the adult noninstitutionalized US population, first focusing on medications previously related to ANA and then considering all medications reported in the National Health and Nutrition Examination Survey (NHANES).

METHODS

Based on NHANES data (1999-2004) for 3608 adults (ages ≥18 years), we estimated odds ratios (ORs) and 95% confidence intervals (CIs) to assess associations between recent medication use and ANA (overall and in sex and age subgroups), adjusted for potential confounders and the survey sampling design.

RESULTS

We found no evidence that most medications previously associated with ANA in specific individuals were risk factors for ANA in the general population, although statistical power was limited for some medications. Overall, ANA were less prevalent in adults who recently used any prescription medications compared with those who did not (OR = 0.73; CI = 0.57,0.93), and likewise several classes of medications were inversely associated with ANA, including hormones (OR = 0.73; CI = 0.55,0.98), thiazide diuretics (OR = 0.43; CI = 0.24,0.79), sulfonylureas (OR = 0.41; CI = 0.19,0.89), and selective serotonin reuptake inhibitor antidepressants (OR = 0.65; CI = 0.42,0.98). Positive associations with ANA were seen for loop diuretics (OR = 1.72; CI = 1.03,2.88) in all adults, and for benzodiazepines (OR = 2.11; CI = 1.09,4.10) and bronchodilators (OR = 1.83; CI = 1.00,3.38) in older (ages ≥60) adults. Estrogens were positively associated with ANA in older women (OR = 1.80; CI = 1.00,3.23) but inversely associated with ANA in younger (ages 18-59) women (OR = 0.43; CI = 0.20,0.93). Regarding individual medications, ANA were positively associated with ciprofloxacin (OR = 4.23; CI = 1.21,14.8), furosemide (OR = 1.79; CI = 1.09,2.93), and omeprazole (OR = 2.05; CI = 1.03,4.10) in all adults, and with salmeterol (OR = 3.76; CI = 1.66,8.52), tolterodine (OR = 6.64; CI = 1.45,30.5), and triamterene (OR = 3.10; CI = 1.08,8.88) in older adults. Also, in younger adults, hydrochlorothiazide was inversely associated with ANA (OR = 0.44; CI = 0.20,0.98).

CONCLUSIONS

Our findings in the general population do not confirm most clinically reported positive associations between specific medications and ANA in some individuals. However, novel positive ANA associations with other medications, as well as unexplained inverse associations with certain classes of medications and overall medication use, deserve further research to clarify the possible roles of medications as risk and protective factors in the development of autoantibodies and autoimmune disease.

CD70 as a target for chimeric antigen receptor T cells in head and neck squamous cell carcinoma

OBJECTIVES

In accordance with the Precision Medicine Initiative, new treatment strategies for head and neck squamous cell carcinoma (HNSCC) are needed to yield better therapeutic outcomes. The purpose of this study was to establish and validate chimeric antigen receptor (CAR)-T cells targets in HNSCC.

METHODS

Putative CAR-T antigens were identified in The Cancer Genome Atlas database. To validate antigen suitability, quantitative RT-PCR, flow cytometry, and immunofluorescent staining were performed. A retroviral human CD70 CAR construct, using truncated CD27 conjugated with 4-1BB and CD3-zeta costimulatory molecules, was used to transduce activated human T cells to generate CD70 CAR-T cells. Cell-based cytotoxicity and cytokine ELISAs were used to measure efficacy of killing.

RESULTS

Nine potential CAR-T targets (CD276, EGFR, MICA, MICB, MAGE-A4, FAP, EPCAM, CD70, B4GALNT1) were identified based on their high expression in tumors compared to flanking control tissues. CD70 was selected for further proof-of-principle analysis based on its differential expression in several tumor subtypes, and showed substantial heterogeneity in individual tumors analyzed. Cell surface CD70 protein and CD70 mRNA were detected from low to high levels in established HNSCC cancer cell lines. CD70 was highly expressed in 4 of 21 tumor biopsies (19%), and 3 of 4 specimens showed strong CD70 expression on the tumor cell surface. CD70-specific CAR-T cells were generated and further demonstrated to recognize and kill CD70-positive HNSCC cells efficiently, but not CD70-negative cancer cells.

CONCLUSION

CD70-specific CAR-T cells specifically recognized and efficiently eliminated CD70-positive HNSCC cells. This study provides the basis for further investigation into CD70 and other CAR-T targets.

Antinuclear antibodies and mortality in the National Health and Nutrition Examination Survey (1999-2004)

OBJECTIVE

Recent studies suggest antinuclear antibodies (ANA) may be related to mortality risk, but evidence is sparse and inconclusive. Thus, we investigated ANA associations with all-cause and cause-specific mortality in U.S. adults.

METHODS

Our sample included 3357 adults (ages ≥20 years) from the 1999-2004 National Health and Nutrition Examination Survey with ANA measurements (1:80 dilution) and mortality data through 2011 (median follow-up: 9.4 years). We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) via weighted Cox regression to assess ANA associations with mortality from all causes, cardiovascular disease (CVD), and cancer. Models adjusted for age, sex, race/ethnicity, education, and obesity. Analyses examined mortality in the full sample and in subgroups based on self-reported histories of CVD and cancer, both overall and stratified by sex and age at enrollment.

RESULTS

Overall, ANA were not strongly associated with death from all causes (HR: 1.13; CI: 0.79, 1.60), from CVD (HR: 1.60; CI: 0.80, 3.20), or from cancer (HR: 1.58; CI: 0.75, 3.33), though all three HR estimates exceeded 1. In the subgroup with a history of cancer, ANA were associated with elevated all-cause mortality in men (HR: 2.28; CI: 1.01, 5.14) and in participants who enrolled at age ≥75 years (HR: 1.99; CI: 1.04, 3.80).

CONCLUSION

These findings suggest that ANA are not strongly associated with mortality in the general population. Longitudinal studies with repeated assessments are needed to understand the temporal relationship between ANA, aging-associated diseases, and mortality.

A Comprehensive Overview on Myositis-Specific Antibodies: New and Old Biomarkers in Idiopathic Inflammatory Myopathy

Autoantibodies specific for idiopathic inflammatory myopathy (myositis-specific autoantibodies (MSAs)) are clinically useful biomarkers to help the diagnosis of polymyositis/dermatomyositis (PM/DM). Many of these are also associated with a unique clinical subset of PM/DM, making them useful in predicting and monitoring certain clinical manifestations. Classic MSAs known for over 30 years include antibodies to Jo-1 (histidyl transfer RNA (tRNA) synthetase) and other aminoacyl tRNA synthetases (ARS), anti-Mi-2, and anti-signal recognition particle (SRP). Anti-Jo-1 is the first autoantibodies to ARS detected in 15-25 % of patients. In addition to anti-Jo-1, antibodies to seven other aminoacyl tRNA synthetases (ARS) have been reported with prevalence, usually 1-5 % or lower. Patients with any anti-ARS antibodies are associated with anti-synthetase syndrome characterized by myositis, interstitial lung disease (ILD), arthritis, Raynaud's phenomenon, and others. Several recent studies suggested heterogeneity in clinical features among different anti-ARS antibody-positive patients and anti-ARS may also be found in idiopathic ILD without myositis. Anti-Mi-2 is a classic marker for DM and associated with good response to steroid treatment and good prognosis. Anti-SRP is specific for PM and associated with treatment-resistant myopathy histologically characterized as necrotizing myopathy. In addition to classic MSAs, several new autoantibodies with strong clinical significance have been described in DM. Antibodies to transcription intermediary factor 1γ/α (TIF1γ/α, p155/140) are frequently found in DM associated with malignancy while anti-melanoma differentiation-associated gene 5 (MDA5; CADM140) are associated with clinically amyopathic DM (CADM) complicated by rapidly progressive ILD. Also, anti-MJ/nuclear matrix protein 2 (NXP-2) and anti-small ubiquitin-like modifier-1 (SUMO-1) activating enzyme (SAE) are recognized as new DM-specific autoantibodies. Addition of these new antibodies to clinical practice in the future will help in making earlier and more accurate diagnoses and better management for patients.

Loukoumasomes Are Distinct Subcellular Structures from Rods and Rings and Are Structurally Associated with MAP2 and the Nuclear Envelope in Retinal Cells

“Rods and rings” (RR) and loukoumasomes are similarly shaped, subcellular macromolecular structures with as yet unknown function. RR, so named because of their shape, are formed in response to inhibition in the GTP or CTP synthetic pathways and are highly enriched in the two key enzymes of the nucleotide synthetic pathway. Loukoumasomes also occur as linear and toroidal bodies and were initially inferred to be the same as RR, largely due to their shared shape and size and the fact that it was unclear if they shared the same subcomponents. In human retinoblastoma tissue and cells we have observed toroidal, perinuclear, macromolecular structures of similar size and antigenicity to those previously reported in neurons (neuronal-loukoumasomes). To further characterize the subcomponents of the retinal-loukoumasomes, confocal analysis following immunocytochemical staining for alpha-tubulin, beta-III tubulin and detyrosinated tubulin was performed. These studies indicate that retinal-loukoumasomes are enriched for beta-III tubulin and other tubulins associated with microtubules. Immunofluorescence together with the in situ proximity ligation assay (PLA), confirmed that beta-III tubulin colocalized with detyrosinated tubulin within loukoumasomes. Our results indicate that these tissues contain only loukoumasomes because these macromolecular structures are immunoreactive with an anti-tubulin antibody but are not recognized by the prototype anti-RR/inosine monophosphate dehydrogenase (IMPDH) antibody (It2006). To further compare the RR and retinal-loukoumasomes, retinoblastoma cells were exposed to the IMPDH-inhibitor ribavirin, a drug known to induce the formation of RR. In contrast to RR, the production of retinal-loukoumasomes was unaffected. Coimmunostaining of Y79 cells for beta-III tubulin and IMPDH indicate that these cells, when treated with ribavirin, can contain both retinal-loukoumasomes and RR and that these structures are antigenically distinct. Subcellular fractionation studies indicate that ribavirin increased the RR subcomponent, IMPDH, in the nuclear fraction of Y79 cells from 21.3 ± 5.8% (0 mM ribavirin) to 122.8 ± 7.9% (1 mM ribavirin) while the subcellular localization of the retinal-loukoumasome subcomponent tubulin went unaltered. Further characterization of retinal-loukoumasomes in retinoblastoma cells reveals that they are intimately associated with lamin folds within the nuclear envelope. Using immunofluorescence and the in situ PLA in this cell type, we have observed colocalization of beta-III tubulin with MAP2. As MAP2 is a microtubule-associated protein implicated in microtubule crosslinking, this supports a role for microtubule crosslinkers in the formation of retinal-loukoumasomes. Together, these results suggest that loukoumasomes and RR are distinct subcellular macromolecular structures, formed by different cellular processes and that there are other loukoumasome-like structures within retinal tissues and cells.

Differential capacity of therapeutic drugs to induce Rods/Rings structures in vitro and in vivo and generation of anti-Rods/Rings autoantibodies

Some HCV patients using ribavirin and interferon alpha (IFN-α) develop anti-rods and rings (RR) autoantibodies, the main target of which is inosine monophosphate dehydrogenase (IMPDH), the rate-determining enzyme in de novo GTP biosynthesis. In vitro inhibition of IMPDH by ribavirin induces RR formation. Here we investigate whether other commonly used drugs that interfere with GTP biosynthesis can induce RR structures in vitro and vivo and elicit generation of autoantibodies. HEp-2 cells treated for 24h with ribavirin, mycophenolic acid (MPA), azathioprine, methotrexate or acyclovir were positive for RR structures. However, adefovir, entecavir, tenofovir and lamivudine did not induce RR structures in these cells. Structures induced by ribavirin in HEp-2 cells are stable after 24h drug-washout, while structures induced by other drugs are relatively labile, disappearing within 2h. Looking at patients treated with these drugs, HCV patients treated with ribavirin (n=17) showed higher average percentage of RR-positive peripheral mononuclear cells than autoimmune patients treated with RR-inducing immunosuppressant drugs (n=21). Serum from 173 autoimmune patients who had been treated with MPA, azathioprine or methotrexate was tested for presence of anti-RR autoantibodies, and only one sample was found to be positive. Conversely, of 48 anti-RR autoantibody positive samples identified at Fleury Laboratories over 30months, 94% were from HCV patients treated with ribavirin plus IFN-α. These data indicate that RR structures can be induced by a variety of drugs in vitro and in vivo, but anti-RR autoantibody production is mostly restricted to HCV patients under ribavirin+IFN-α treatment.

Dr Eng M. Tan: a tribute to an enduring legacy in autoimmunity

At the age of ninety years, Dr Eng Meng Tan has had a remarkable impact on the accumulated knowledge of autoimmune diseases, including seminal findings in systemic lupus erythematosus (SLE) and a wide range of other autoimmune diseases. Dating to the first description of the Sm (Smith) autoantibody in SLE, his focus has been the use of autoantibodies as probes to identify and elucidate novel cellular molecules and then translating these discoveries into biomarkers and immunoassays for a wide range of these diseases and, later, cancer. He led efforts to standardize autoantibody nomenclature and testing protocols. Through his mentorship a great number of trainees and collaborators have had remarkably successful careers, and by that virtue he has garnered a remarkable continuing legacy.

MicroRNA-375 as a biomarker for malignant transformation in oral lesions

OBJECTIVE

Malignant transformation of oral premalignant lesions is the key process in the progression to oral squamous cell carcinoma (OSCC). Previously, we identified miR-7 and miR-21 as candidate oncogenes and miR-375 and miR-494 as candidate tumor suppressors in OSCC. We aim to evaluate these microRNAs as biomarkers of malignant transformation in oral premalignant lesions.

STUDY DESIGN

Formalin-fixed, paraffin-embedded samples from progressive premalignant lesions and paired sequential OSCC tumors at the same site were obtained from same patients (n = 31). Total RNA was extracted and analyzed for microRNA levels using real-time polymerase chain reaction.

RESULTS

MiR-375 expression in progressive lesions was clearly lower than in nonprogressive control lesions (average eightfold difference, P = .0004). Furthermore, the expression of miR-375 decreased significantly after the progression from premalignant lesion to OSCC (P < .0001). Receiver operating characteristic curve analysis revealed that miR-375 was able to differentiate between progressive and nonprogressive premalignant lesions (P < .0001).

CONCLUSIONS

MiR-375 downregulation in oral premalignant lesions is associated with a higher risk of malignant transformation.

'Rod and ring' formation from IMP dehydrogenase is regulated through the one-carbon metabolic pathway

'Rods and rings' (RRs) are conserved, non-membrane-bound intracellular polymeric structures composed, in part, of inosine monophosphate dehydrogenase (IMPDH), a key enzyme leading to GMP and GTP biosynthesis. RR formation is induced by IMPDH inhibitors as well as glutamine deprivation. They also form upon treatment of cells with glutamine synthetase inhibitors. We now report that depriving cells of serine and glycine promotes RR formation, and we have traced these effects to dihydrofolate reductase (DHFR) and serine hydroxymethyltransferase-2 (SHMT2), pivotal enzymes in one-carbon metabolism and nucleotide biosynthesis. RR assembly is likewise induced upon DHFR inhibition by methotrexate or aminopterin as well as siRNA-mediated knockdown of DHFR or SHMT2. Because RR assembly occurs when guanine nucleotide biosynthesis is inhibited, and because RRs rapidly disassemble after the addition of guanine nucleotide precursors, RR formation might be an adaptive homeostatic mechanism, allowing IMPDH to sense changes in the one-carbon folate pathway.

Periodontal bacterial colonization in synovial tissues exacerbates collagen-induced arthritis in B10.RIII mice

Background

It has been previously hypothesized that oral microbes may be an etiological link between rheumatoid arthritis (RA) and periodontal disease. However, the mechanistic basis of this association is incompletely understood. Here, we investigated the role of periodontal bacteria in induction of joint inflammation in collagen-induced arthritis (CIA) in B10.RIII mice.

Methods

CIA-prone B10.RIII mice were infected orally with a polybacterial mixture of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia for 24 weeks before induction of CIA. The ability of polybacterial mixture to colonize the periodontium and induce systemic response, horizontal alveolar bone resorption in infected B10.RIII mice was investigated. Arthritis incidence, severity of joint inflammation, pannus formation, skeletal damage, hematogenous dissemination of the infection, matrix metalloproteinase 3 (MMP3) levels, and interleukin-17 expression levels were evaluated.

Results

B10.RIII mice had gingival colonization with all three bacteria, higher levels of anti-bacterial immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies, significant alveolar bone resorption, and hematogenous dissemination of P. gingivalis to synovial joints. Infected B10.RIII mice had more severe arthritis, and higher serum matrix metalloproteinase 3 levels and activity. Histopathological analysis showed increased inflammatory cell infiltration, destruction of articular cartilage, erosions, and pannus formation. Additionally, involved joints showed had expression levels of interleukin-17.

Conclusion

These findings demonstrate that physical presence of periodontal bacteria in synovial joints of B10.RIII mice with collagen-induced arthritis is associated with arthritis exacerbation, and support the hypothesis that oral bacteria, specifically P. gingivalis, play a significant role in augmenting autoimmune arthritis due to their intravascular dissemination to the joints.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1056-4) contains supplementary material, which is available to authorized users.

A re-evaluation of anti-NA-14 antibodies in patients with primary Sjögren's syndrome: Significant role of interferon-γ in the production of autoantibodies against NA-14

Novel autoantibodies against nuclear antigen of 14 kDa (NA-14)/Sjögren's syndrome nuclear antigen-1 (SSNA-1) are predominantly recognized in sera of patients with primary Sjögren's syndrome (pSS). However, the detailed characteristics of the anti-NA-14 antibody remain unknown. Here, we sought to clarify the characteristics of anti-SSNA-1/NA-14 antibodies and the mechanisms of autoantibody production using sera from patients with connective tissue diseases (including pSS), autoimmune sera reacting with standard autoantigens (SS-A/Ro and/or SS-B/La, ds DNA, Scl-70 and Jo-1), and normal healthy controls (NHCs). Anti-NA-14 antibodies were predominantly recognized in sera from patients with pSS and in autoimmune sera reacting with thSS-A/Ro and/or -SS-B/Lo. Indirect immunofluorescence analysis showed that NA-14 was strongly expressed in mitotic-phase cells. Patients with pSS having anti-NA-14 antibodies exhibited significant elevation of serum IP-10 and BAFF compared to that in patients with pSS without anti-NA-14 antibodies and NHCs. Thus, our data demonstrated that anti-NA-14 antibodies could be classified as novel autoantibodies reacting with mitosis-related autoantigens predominantly recognized in pSS. Moreover, interferon-γ played an important role in the production of anti-NA-14 autoantibodies as patients with pSS having anti-NA-14 antibodies exhibited increased serum levels of IP-10 and BAFF.

From autoantibody research to standardized diagnostic assays in the management of human diseases – report of the 12th Dresden Symposium on Autoantibodies

Testing for autoantibodies (AABs) is becoming more and more relevant, not only for diagnosing autoimmune diseases (AIDs) but also for the differentiation of defined AID subtypes with different clinical manifestations, course and prognosis as well as the very early diagnosis for adequate management in the context of personalized medicine. A major challenge to improve diagnostic accuracy is to harmonize or even standardize AAB analyses. This review presents the results of the 12th Dresden Symposium on Autoantibodies that focused on several aspects of improving autoimmune diagnostics. Topics that are addressed include the International Consensus on ANA Patterns (ICAP) and the International Autoantibody Standardization (IAS) initiatives, the optimization of diagnostic algorithms, the description and evaluation of novel disease-specific AABs as well as the development and introduction of novel assays into routine diagnostics. This review also highlights important developments of recent years, most notably the improvement in diagnosing and predicting the course of rheumatoid arthritis, systemic sclerosis, idiopathic inflammatory myopathies, and of autoimmune neurological, gastrointestinal and liver diseases; the potential diagnostic role of anti-DFS70 antibodies and tumor-associated AABs. Furthermore, some hot topics in autoimmunity regarding disease pathogenesis and management are described.

Report on the second International Consensus on ANA Pattern (ICAP) workshop in Dresden 2015

The second meeting for the International Consensus on Antinuclear antibody (ANA) Pattern (ICAP) was held on 22 September 2015, one day prior to the opening of the 12th Dresden Symposium on Autoantibodies in Dresden, Germany. The ultimate goal of ICAP is to promote harmonization and understanding of autoantibody nomenclature, and thereby optimizing ANA usage in patient care. The newly developed ICAP website www.ANApatterns.org was introduced to the more than 50 participants. This was followed by several presentations and discussions focusing on key issues including the two-tier classification of ANA patterns into competent-level versus expert-level, the consideration of how to report composite versus mixed ANA patterns, and the necessity for developing a consensus on how ANA results should be reported. The need to establish on-line training modules to help users gain competency in identifying ANA patterns was discussed as a future addition to the website. To advance the ICAP goal of promoting wider international participation, it was agreed that there should be a consolidated plan to translate consensus documents into other languages by recruiting help from members of the respective communities.

Single-cell antibody nanowells: a novel technology in detecting anti-SSA/Ro60- and anti-SSB/La autoantibody-producing cells in peripheral blood of rheumatic disease patients

Background

Anti-SSA/Ro60 and anti-SSB/La are essential serological biomarkers for rheumatic diseases, specifically Sjögren’s syndrome (SS) and systemic lupus erythematosus (SLE). Currently, laboratory detection technology and platforms are designed with an emphasis on high-throughput methodology; therefore, the relationship of sensitivity with specificity remains a significant area for improvement. In this study, we used single-cell antibody nanowells (SCAN) technology to directly profile individual B cells producing antibodies against specific autoantigens such as SSA/Ro60 and SSB/La.

Methods

Peripheral blood mononuclear cells were isolated using Ficoll gradient. Fluorescently labeled cells were added to fabricated nanowells and imaged using a high-speed epifluorescence microscope. The microengraving process was conducted using printed slides coated with immunoglobulins. Printed slides were hybridized with fluorescence-conjugated immunoglobulin G (IgG), SSA/Ro60, and SSB/La antigens. Microarray spots were analyzed for nanowells with single live B cells that produced antigen-specific autoantibodies.

Results

Our results indicate that SCAN can simultaneously detect high frequencies of anti-SSA/Ro60 and anti-SSB/La with a specific IgG isotype in peripheral blood mononuclear cells of patients, as well as measure their individual secretion levels. The data showed that patients with SS and SLE exhibited higher frequency and greater concentration of anti-SSA/Ro60- and anti-SSB/La-producing B cells in the IgG isotype. Furthermore, individual B cells of patients produced higher levels of IgG-specific anti-SSA/Ro60 autoantibody, but not IgG-specific anti-SSB/La autoantibody, compared with healthy control subjects.

Conclusions

These results support the application of SCAN as a robust multiparametric analytical bioassay that can directly measure secretion of autoantibody and accurately report antigen-specific, autoantibody-producing cells.

International consensus on ANA patterns (ICAP): the bumpy road towards a consensus on reporting ANA results

The International Consensus on ANA Patterns (ICAP) was initiated as a workshop aiming to thoroughly discuss and achieve consensus regarding the morphological patterns observed in the indirect immunofluorescence assay on HEp-2 cells. One of the topics discussed at the second ICAP workshop, and addressed in this paper, was the harmonization of reporting ANA test results. This discussion centered on the issue if cytoplasmic and mitotic patterns should be reported as positive or negative. This report outlines the issues that impact on two major different reporting methods. Although it was appreciated by all participants that cytoplasmic and mitotic patterns are clinically relevant, implications for existing diagnostic/classification criteria for ANA-associated diseases in particular hampered a final consensus on this topic. Evidently, a more concerted action of all relevant stakeholders is required. Future ICAP workshops may help to facilitate this action.

Report of the First International Consensus on Standardized Nomenclature of Antinuclear Antibody HEp-2 Cell Patterns 2014-2015

During the 12th International Workshop on Autoantibodies and Autoimmunity held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the international consensus on antinuclear antibody pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care.

Report of the First International Consensus on Standardized Nomenclature of Antinuclear Antibody HEp-2 Cell Patterns 2014-2015

During the 12th International Workshop on Autoantibodies and Autoimmunity held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the international consensus on antinuclear antibody pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care.

Assembly of IMPDH2-based, CTPS-based, and mixed rod/ring structures is dependent on cell type and conditions of induction

Inhibition of guanosine triphosphate (GTP) and cytidine triphosphate (CTP) biosynthetic pathways induces cells to assemble rod/ring (RR) structures, also named cytoophidia, which consist of the enzymes cytidine triphosphate synthase (CTPS) and inosine-5'-monophosphate dehydrogenase 2 (IMPDH2). We aim to explore the interaction of CTPS and IMPDH2 in the generation of RR structures. HeLa and COS-7 cells were cultured in normal conditions or in the presence of 6-diazo-5-oxo-L-norleucine (DON), ribavirin, or mycophenolic acid (MPA). Over 90% of DON-treated cells presented RR structures. In HeLa cells, 35% of the RR structures were positive for IMPDH2 alone, 26% were CTPS alone, and 31% were IMPDH2/CTPS mixed, while in COS-7 cells, 42% of RR were IMPDH2 alone, 41% were CTPS alone, and 10% were IMPDH2/CTPS mixed. Ribavirin and MPA treatments induced only IMPDH2-based RR. Cells were also transfected with an N-terminal hemagglutinin (NHA)-tagged CTPS1 construct. Over 95% of NHA-CTPS1 transfected cells with DON treatment presented IMPDH2-based RR and almost 100% presented CTPS1-based RR; when treated with ribavirin, over 94% of transfected cells presented IMPDH2-based RR and 37% presented CTPS1-based RR, whereas 2% of untreated transfected cells presented IMPDH2-based RR and 28% presented CTPS1-based RR. These results may help in understanding the relationship between CTP and GTP biosynthetic pathways, especially concerning the formation of filamentous RR structures.

Interleukin 1β-Responsive MicroRNA-146a Is Critical for the Cytokine-Induced Tolerance and Cross-Tolerance to Toll-Like Receptor Ligands

Unwarranted overproduction of cytokines, such as interleukin (IL)-1β, can cause moderate to severe pathological complications, and thus elaborate mechanisms are needed to regulate its onset and termination. One such, well-known, mechanism is endotoxin tolerance, generally described as controlling lipopolysaccharide Toll-like receptor 4 (LPS-TLR4) signaling. Similarly, cytokine-induced tolerance plays an important role in regulating an overactive cytokine response. In this report, the capability of IL-1β to induce tolerance and cross-tolerance to various inflammatory ligands was investigated. IL-1β-stimulated THP-1 monocytes showed a gradual increase of microRNA (miR)-146a, reaching 15-fold expression by 24 h. miR-146a upregulation induced tolerance toward subsequent challenges of IL-1β, LPS, peptidoglycan, Pam and flagellin in THP-1 cells. The induction of tolerance was dependent on the IL-1β priming dose and associated increase of miR-146a expression. Moreover, IL-1β-treated THP-1 cells showed sustained miR-146a upregulation that repressed IRAK1 and TRAF6 adaptor molecules. Transfection of miR-146a alone mimicked IL-1β-induced tolerance in monocytes, while cells transfected with miR-146a inhibitor increased chemokine production. A comparable cytokine response regulated by miR-146a was also detected in lung epithelial A549 cells, purified human monocytes and mouse peritoneal macrophages. Thus, our studies showed that miR-146a was crucial for monocytic cell-based IL-1β tolerance and cross-tolerance, and thus opens the way for future research in the development of therapeutics for inflammatory diseases.