Differences in the transcriptome response in the gills of sea lamprey acutely exposed to 3-trifluoromethyl-4-nitrophenol (TFM), niclosamide or a TFM:niclosamide mixture

Sea lamprey (Petromyzon marinus) control in the Laurentian Great Lakes of North America makes use of two pesticides: 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide, which are often co-applied. Sea lamprey appear to be vulnerable to these agents resulting from a lack of detoxification responses with evidence suggesting that lampricide mixtures produce a synergistic effect. However, there is a lack of information pertaining to the physiological responses of sea lamprey to niclosamide and TFM:niclosamide mixtures. Here, we characterized the transcriptomic responses of the sea lamprey to TFM, niclosamide, and a TFM:niclosamide (1.5 %) mixture in the gill. Along with a control, larval sea lamprey were exposed to each treatment for 6 h, after which gill tissues were extracted for measuring whole-transcriptome responses using RNA sequencing. Differential gene expression patterns were summarized, which included identifying the broad roles of genes and common expression patterns among the treatments. While niclosamide treatment resulted in no differentially expressed genes, TFM- and mixture-treated fish had several differentially expressed genes that were associated with the cell cycle, DNA damage, metabolism, immune function, and detoxification. However, there was no common differential expression among treatments. For the first time, we characterized the transcriptomic response of sea lamprey to niclosamide and a TFM:niclosamide mixture and identified that these agents impact mRNA transcript abundance of genes associated with the cell cycle and cellular death, and immune function, which are likely mediated through mitochondrial dysregulation. These results may help to inform the production of more targeted and effective lampricides in sea lamprey control efforts.

Episcleritis and periorbital edema secondary to VEXAS syndrome

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a newly described autoinflammatory entity caused by a UBA-1 gene mutation. Among the most frequent symptoms it produces fever, cytopenias, polychondritis, pulmonary infiltrates and up to 40% ocular involvement such as periorbital edema, uveitis, episcleritis, scleritis and retinal vasculitis. Patients respond to high doses of corticosteroids, however, many end up being refractory to them and to the classic immunosuppressants. We described the case of a 77-year-old male patient with ocular involvement in the form of episcleritis and periorbital edema who was later diagnosed with VEXAS Syndrome. The patient, after failing treatment with immunosuppressants, is currently receiving treatment with oral steroids and tocilizumab. Ophthalmologist must be aware of the ophthalmological affectation of autoinflammatory diseases and especially of this new entity described as the VEXAS Syndrome.

Improved cytosine base editors generated from TadA variants

Cytosine base editors (CBEs) enable programmable genomic C·G-to-T·A transition mutations and typically comprise a modified CRISPR-Cas enzyme, a naturally occurring cytidine deaminase, and an inhibitor of uracil repair. Previous studies have shown that CBEs utilizing naturally occurring cytidine deaminases may cause unguided, genome-wide cytosine deamination. While improved CBEs that decrease stochastic genome-wide off-targets have subsequently been reported, these editors can suffer from suboptimal on-target performance. Here, we report the generation and characterization of CBEs that use engineered variants of TadA (CBE-T) that enable high on-target C·G to T·A across a sequence-diverse set of genomic loci, demonstrate robust activity in primary cells and cause no detectable elevation in genome-wide mutation. Additionally, we report cytosine and adenine base editors (CABEs) catalyzing both A-to-I and C-to-U editing (CABE-Ts). Together with ABEs, CBE-Ts and CABE-Ts enable the programmable installation of all transition mutations using laboratory-evolved TadA variants with improved properties relative to previously reported CBEs.

Transcriptomic impacts and potential routes of detoxification in a lampricide-tolerant teleost exposed to TFM and niclosamide

Sea lamprey (Petromyzon marinus) control in the Laurentian Great Lakes of North America often relies on the application of 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide mixtures to kill larval sea lamprey. Selectivity of TFM against lampreys appears to be due to differential detoxification ability in these jawless fishes compared to bony fishes, particularly teleosts. However, the proximate mechanisms of tolerance to the TFM and niclosamide mixture and the mechanisms of niclosamide toxicity on its own are poorly understood, especially among non-target fishes. Here, we used RNA sequencing to identify specific mRNA transcripts and functional processes that responded to niclosamide or a TFM:niclosamide mixture in bluegill (Lepomis macrochirus). Bluegill were exposed to niclosamide or TFM:niclosamide mixture, along with a time-matched control group, and gill and liver tissues were sampled at 6, 12, and 24 h. We summarized the whole-transcriptome patterns through gene ontology (GO) term enrichment and through differential expression of detoxification genes. The niclosamide treatment resulted in an upregulation of several transcripts associated with detoxification (cyp, ugt, sult, gst), which may help explain the relatively high detoxification capacity in bluegill. Conversely, the TFM:niclosamide mixture resulted in an enrichment of processes related to arrested cell cycle and growth, and cell death alongside a diverse detoxification gene response. Detoxification of both lampricides likely involves the use of phase I and II biotransformation genes. Our findings strongly suggest that the unusually high tolerance of bluegill to lampricides is due to these animals having an inherently high capacity and flexible detoxification response to such compounds.

Variation in the Transcriptome Response and Detoxification Gene Diversity Drives Pesticide Tolerance in Fishes

Pesticides are critical for invasive species management but often have negative effects on nontarget native biota. Tolerance to pesticides should have an evolutionary basis, but this is poorly understood. Invasive sea lamprey (Petromyzon marinus) populations in North America have been controlled with a pesticide lethal to them at lower concentrations than native fishes. We addressed how interspecific variation in gene expression and detoxification gene diversity confer differential pesticide sensitivity in two fish species. We exposed sea lamprey and bluegill (Lepomis macrochirus), a tolerant native species, to 3-trifluoromethyl-4-nitrophenol (TFM), a pesticide commonly used in sea lamprey control. We then used whole-transcriptome sequencing of gill and liver to characterize the cellular response in both species. Comparatively, bluegill exhibited a larger number of detoxification genes expressed and a larger number of responsive transcripts overall, which likely contributes to greater tolerance to TFM. Understanding the genetic and physiological basis for pesticide tolerance is crucial for managing invasive species.

POS0244 ASSOCIATION OF PROTEINASE 3 GENE (PRTN3) Val119Ile POLYMORPHISM (SNP rs351111) WITH RISK OF RELAPSE AMONG HOMOZYGOUS PATIENTS WITH PR3 ANCA-ASSOCIATED VASCULITIS

Background

The frequency of the proteinase 3 gene (PRTN3) polymorphisms in patients with ANCA-associated vasculitis (AAV) is not well characterized. We hypothesize that PRTN3 gene polymorphisms induce allosteric changes in PR3 conformation which may alter its interaction with ligands and PR3-ANCA during inflammation with potential implications for disease presentation and clinical outcomes.

Objectives

To analyze the association of PRTN3 Val119Ile polymorphism (SNP rs351111) with risk of relapse risk among homozygous patients with PR3 ANCA-associated vasculitis.

Methods

DNA variant calling for SNP rs351111 (chr.19:844020, c.355G>A) in PRTN3 gene assessed the allelic frequency in patients with PR3-AAV included in the Rituximab versus Cyclophosphamide (RAVE) trial. This was followed by RNA-seq variant calling to characterize the mRNA expression. We compared clinical presentation and outcomes between patients homozygous for PR3-Ile119 or PR3-Val119.

Results

Serum samples for DNA calling were available in 188 of the 197 patients with AAV in the RAVE cohort. 75 PR3-AAV patients had the allelic variant: 13 patients were homozygous for PR3-Ile119 and 62 patients were heterozygous PR3-Val119Ile with an allele frequency threshold of 29.3 – 55.1% of reads (Figure 1A and 1B). RNA-seq was available for 89 patients and the mRNA corresponding to the allelic variant was found in 35 PR3-AAV patients: 13 patients were homozygous for PR3-Ile119 and 22 patients were heterozygous PR3-Val119Ile with an allele frequency threshold of 11.1 – 62.8% of reads (Figure 1A and 1C). The agreement between the DNA calling results and the mRNA expression of the 86 patients that overlapped was 100%. We found an additional homozygous patient for PR3-Val119 in which blood was not available for DNA calling. We compared the clinical presentation and outcomes of 74 patients with PR3-AAV: 13 homozygous for PR3-Ile119 and 51 homozygous for PR3-Val119 (Table 1). The frequency of severe flares at 18 months in homozygous PR3-Ile119 was ≥ 2x higher when compared with homozygous PR3-Val119 (46.2% vs. 19.6%, p=0.048). We found no differences in clinical presentation.

Figure 1.

RAVE trial population distribution according to the zygosity status for PRTN3 gene (PR3 and MPO-ANCA patients) and DNA or RNA variant calling (panel A). Allelic frequency for rs351111, chr.19:844020 (c.355G>A) in PRTN3 among patients with AAV (PR3 and MPO-ANCA) in the DNA (panel B) and RNA (panel C) variant calling.

Table 1.

Outcomes of patients with PR3-ANCA according with PRTN3 zygosity.

PR3-ANCA (n=64)Homozygous PR3-Val119(n=51)HomozygousPR3-Ile119(n=13)p-value Remission, n (%)45 (88.2)13 (100)0.194 Complete remission, n (%)36 (70.6)10 (76.9)0.650 Any flare 18 months, n (%)30 (58.8)7 (53.8)0.746 Severe Relapse* 18 months, n (%)10 (19.6)6 (46.2)0.048

* Relapse was considered “Severe” if Birmingham Vasculitis Activity Score for Wegener’s Granulomatosis (BVAS/WG) > 3 or one major item as per the RAVE trial definition.

Abbreviations: ANCA - anti-neutrophil cytoplasmic antibody; Ile – isoleucine; n- number; PR3 - proteinase 3; Val - valine.

Conclusion

In patients with PR3-AAV the presence of PRTN3 Val119Ile polymorphism was associated with higher frequency of severe relapse. Further studies are necessary to understand the association of this observation with the risk of severe relapse.

References

[1]Stone JH et al N Engl J Med 2010; 363:221-232

Disclosure of Interests

None declared

POS0802 18F-FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY AS A PREDICTOR OF ANGIOGRAPHIC PROGRESSION OF DISEASE IN LARGE-VESSEL VASCULITIS

Background:

Giant cell arteritis (GCA) and Takayasu’s arteritis (TAK) are the two main forms of large-vessel vasculitis (LVV). Although angiography is essential to detect vascular disease in patients with LVV, there is limited prospective data characterizing change in arterial lesions over time, and factors that predict angiographic change remain unknown.

Objectives:

The objectives of this study were to: 1) describe longitudinal change in angiographic studies in patients with GCA and TAK and 2) determine whether FDG-PET activity predicts angiographic progression of disease.

Methods:

Patients with GCA or TAK were recruited into a prospective, observational cohort. All patients underwent baseline magnetic resonance (MR) or computed tomography (CT) angiography and a follow-up study (same modality) ≥6 months after baseline per a standardized imaging protocol. For patients who had multiple angiograms, the baseline and most recent images were compared. Arterial lesions, defined as stenosis, occlusion, or aneurysm, were evaluated by visual inspection in 4 segments of the aorta and 13 branch arteries by a single reader blinded to clinical status. On follow up angiography, the development of new lesions in these same territories was recorded, and existing lesions were characterized as improved, worsened, or unchanged by visual inspection, with confirmation by an independent reader.

All patients underwent FDG-PET on the same date as angiography. Qualitative assessment of FDG uptake was performed in each corresponding arterial territory evaluated by angiography. Active vasculitis was defined as greater FDG uptake in the arterial wall compared to the liver by visual inspection.

Results:

At the baseline visit, there were 248 arterial lesions (21%) out of 1162 arterial territories evaluated from 70 patients with LVV (TAK=38; GCA=32). Baseline characteristics were as follows: Age [TAK=29.5 years (18.4-39.5), GCA=69.6 years (60.7-75.5)], Female gender [TAK=30 patients (79%), GCA=23 patients (72%)], Disease duration [TAK=2.2 years (0.6-5.5), GCA=0.7 years (0.1-2.6)], Active clinical disease [TAK=17 patients (45%), GCA=20 patients (63%)].

Over 1.6 years (1.0-2.7) of median follow-up, no angiographic change was observed in 1,132 (97%) arterial territories. New lesions developed in 8 arterial territories, exclusively in 5 patients with TAK. Arterial lesions improved in 16 territories (GCA = 7, TAK = 9) and worsened in 6 territories (GCA = 1, TAK = 5). Patients with angiographic improvement were initially imaged earlier in the disease course compared to patients with new/worsening lesions (median 1.1 vs 16.4 months, p=0.09). Patients with angiographic improvement had significantly lower acute phase reactants at follow-up compared to patients with new/worsening arterial lesions [median ESR 3.0 (2.0-15.0) vs. 27.0 (7.3-39) mm/h, p<0.01; median CRP 0.7 (0.3-1.4) vs. 6.1 (3.1-19.6) mg/L, p<0.01]. Seventy-nine percent of patients with new/worsening arterial lesions had received increased treatment over the follow-up interval compared to 100% patients with improved arterial lesions, p=0.09.

FDG-PET activity was evaluated in 1091/1162 (94%) of corresponding arterial territories. PET activity in an arterial territory at baseline was significantly associated with change in that arterial territory (either new/worsening or improvement) on follow-up angiography (p<0.01) (FIGURE 1). PET activity had a sensitivity of 80% and specificity of 74% for predicting change in arterial lesions. Most arterial territories without PET activity at baseline remained unchanged over time by angiography, yielding a negative predictive value of 99%. (FIGURE 1).

Conclusion:

Development of new arterial lesions is infrequent in LVV. Change in arterial lesions is dynamic, and improvement can occur. FDG-PET activity predicts change in angiographic lesions, and lack of PET activity is strongly associated with stable angiographic disease. These data may inform guideline recommendations for imaging monitoring in LVV.

Figure 1.

Disclosure of Interests:

None declared

POS1373 DEFINING EAR CHONDRITIS: DATA FROM 685 PATIENTS WITH RELAPSING POLYCHONDRITIS

Background:

Ear chondritis is often considered the pathognomonic feature of relapsing polychondritis (RP). Although painful redness and swelling of the pinna and a resultant cauliflower ear are universally recognized as chondritis, the complete spectrum of symptoms associated with ear chondritis have not been well described.

Objectives:

The study objective was to seek patient input to help characterize ear chondritis An online survey was administered in English or Spanish to participants with self-reported RP.

Methods:

Participants were asked questions about their ear pain, including quality, location, duration, aggravating/alleviating factors, timing of onset and duration. Participants were included who reported age ≥ 18 years, a diagnosis of RP confirmed by a physician, and sufficient symptoms to meet McAdams or Damiani’s diagnostic criteria. Participants were categorized as having “typical ear chondritis” if they reported ear pain localized to the pinna with associated redness and swelling. Atypical presentations of ear chondritis were also considered.

Results:

A total of 685 participants from five continents completed the survey. Among them, 659 met inclusion criteria for subsequent analysis. Most participants were female (n=574; 87%), white (n=548; 83%) and from the United States (n=484;74%). The median age was 50 years (interquartile range = 41-58). In total, 593 (90%) patients reported ear pain, 227 (38%) had “typical ear chondritis”, and 98 (16%) had cauliflower ear.

Ear pain was most commonly described as burning (n=334, 56%) or throbbing (n=295, 50%). The most common location of pain was the pinna (n=373, 63%). Participants reported ear redness (n=454, 60%) and swelling (n=405, 62%). Some patients experienced only ear redness without swelling (n=286, 48%) or only ear swelling without redness (n=71, 12%). The most common aggravating factors were minor trauma (n=371, 62%) and stress (n=358, 60%). The most common alleviating factor was avoidance of touching the ear (n=374, 63%). Pain was most frequently reported during the daytime (n=355, 60%) and most likely to occur in either ear at different times (n=310, 52%). Onset could be gradual (n=198, 33%) or sudden (n=155, 26%). Pain typically lasted a few hours (n=175, 30%) or 2-3 days (n=130, 22%). The majority of patients who had pinna pain also had pain in other parts of the ear (e.g. mastoid process, inner ear, whole ear) at some point (n=394, 67%). In patients with cauliflower ear, the most common location of pain was the pinna (n=57, 58%) followed by pain inside the ear (n=53, 54%). Most participants reported at least two different types of pain (n=420, 64%).

Conclusion:

Ear chondritis in patients with RP has a wide range of clinical presentations and characteristics beyond the typical triad of redness, swelling, and pain localized to the pinna. The description of pain often significantly varies within the same patient. Knowledge of the various distinct characteristics of ear involvement in RP may help physicians recognize and monitor the disease more effectively.

Disclosure of Interests:

None declared

OP0090 CLASSIFICATION OF PATIENTS WITH RELAPSING POLYCHONDRITIS BASED ON SOMATIC MUTATIONS IN UBA1

Background:

Somatic mutations in ubiquitin activating enzyme 1 (UBA1) cause a newly defined syndrome known as VEXAS. [1] More than fifty percent of patients currently identified with VEXAS meet diagnostic criteria for relapsing polychondritis (RP).

Objectives:

To determine the prevalence VEXAS within a cohort of patients with RP, to compare their clinical, laboratory, and immunologic features and to develop a clinical algorithm to inform genetic screening for VEXAS among patients with RP.

Methods:

Exome and targeted sequencing of the UBA1 gene was performed in a prospective observational cohort of patients with RP. Clinical and immunological characteristics of patients with RP were compared based on presence or absence of UBA1 mutations. Random forest was used to derive a clinical algorithm to identify patients with UBA1 mutations. Immune populations were quantified by multipanel flow cytometry. Categorical and continuous variables were compared using the chi square or Kruskal-Wallis test. P<0.05 defined statistical significance.

Results:

Seven of 92 patients with RP (7.6%) were confirmed to have UBA1 mutations (VEXAS-RP). Six additional patients with VEXAS-RP from other cohorts were included for subsequent analyses. Patients with VEXAS-RP were all male, older at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. Patients with RP as compared with VEXAS-RP had a significantly higher prevalence of airway chondritis, costochondritis and tenosynovitis/arthralgias. (Table). Mortality was significantly greater in VEXAS-RP than RP (27% vs 2% p=0.01). Maximum ESR, CRP, and mean corpuscular volume (MCV) values were significantly greater in VEXAS-RP. Absolute monocyte, lymphocyte, and platelet counts were significantly lower in VEXAS-RP. A decision tree based on male sex, MCV>100 fl and Platelet count<200 K/ul classified between VEXAS-RP and RP with 100% sensitivity and 96% specificity.

Table 1.

Clinical Characteristics of patients with RP vs VEXAS-RP

All Patientsn=98RPn=85VEXAS-RPn=13p valueDemographic CharacteristicsRace, White n (%)90 (92)77 (91)13 (100)0.59Sex, Male n (%)26 (27)13 (15)13 (100)<0.0001Age, Symptom onset, years, Median (IQR)38 (30-47)37 (28-43)56 (54-64)<0.0001Clinical SymptomsFever n (%)33 (34)20 (24)13 (100)<0.0001Ear chondritis n (%)61 (62)48 (56)13 (100)0.0015Nose chondritis n (%)83 (85)71 (84)12 (92)0.68Airway chondritis n (%)37 (38)37 (44)0 (0)0.0015Tenosynovitis/arthalgias n (%)83 (85)77 (91)6 (46)0.0005Skin involvement n (%)33 (34)22 (2611 (85)<0.0001Laboratory ValuesESR, mm/hr, median (IQR)12 (6-22)11 (5-19)66.5 (42-110)<0.0001CRP, mg/L, median (IQR)2.9 (0.8-9.6)1.9 (0.6-6.3)17.7 (9.6-99.5)<0.0001Platelet count (k/uL)246(201-299)258 (227-312)145 (100-169)<0.0001MCV fL93.05 (90-98)92.2 (89-95)105 (102-115)<0.0001Absolute lymphocyte count1.6 (1.1-2.3)1.78(1.4-2.4)0.92 (0.5-1.2)<0.0001CT scan abnormalitiesPulmonary infiltrates n (%)16 (16.33)6 (7.06)10 (77)<0.0001ComplicationsDeath n (%)6 (6)3 (4)3 (23)0.029Unprovoked DVT12 (12)4 (5)8 (62)<0.0001

N number; IQR = interquartile range

Conclusion:

Mutations in UBA1 are causal for disease in a subset of patients with RP. These patients are defined by disease onset in the fifth decade of life or later, male sex, ear/nose chondritis and hematologic abnormalities. Early identification is important in VEXAS given the associated high mortality rate.

References:

[1]Beck DB, Ferrada MA, Sikora KA, Ombrello AK, Collins JC, Pei W, Balanda N, Ross DL, Ospina Cardona D, Wu Z et al: Somatic Mutations in UBA1 and Severe Adult-Onset Autoinflammatory Disease. N Engl J Med 2020, 383(27):2628-2638.

Disclosure of Interests:

None declared

SAT0251 ANGIOGRAPHIC PROGRESSION OF DISEASE IN LARGE-VESSEL VASCULITIS

Background:

Angiography is essential to detect vascular disease in patients with large-vessel vasculitis (LVV). Guidelines differ on the role of periodic angiography to monitor patients with LVV, in part because there is limited prospective data characterizing the natural history of angiographic disease. Development of new areas of arterial damage, even in periods of apparent clinical remission, has been reported in LVV; however, whether this is a common or rare phenomenon is unknown.

Objectives:

To characterize angiographic progression of disease over time in Takayasu’s arteritis (TAK) compared to giant cell arteritis (GCA).

Methods:

Patients with GCA or TAK were recruited into a prospective, observational cohort. Patients fulfilled the 1990 American College of Rheumatology (ACR) Classification Criteria for TAK or modified 1990 ACR Criteria for GCA. All patients underwent baseline magnetic resonance angiography (MRA) and a follow-up MRA at least one year after baseline per a standardized imaging protocol. The presence of angiographic lesions, defined as stenosis, occlusion, or aneurysm, was evaluated by visual inspection by a single reader who was blinded to clinical status. Angiographic lesions were evaluated in 4 segments of the aorta and in 13 branch arteries. On follow up angiography, the development of new lesions was recorded, and existing lesions were characterized as improved, worsened, or unchanged.

Results:

782 arterial territories were evaluated from 46 patients with LVV (TAK=28; GCA=18). Baseline characteristics were as follows: Age [TAK=24.8 years (18.6-34.9), GCA=64.8 years (57.8-73.9)], Female gender [TAK=21 patients (78%), GCA=16 patients (84%)], Disease duration [TAK=2.3 years (0.6-4.9), GCA 1.2 years (0.4-2.9)], Active clinical disease [TAK=12 patients (44%), GCA 12 patients (63%)]. The median time from initial MRA to follow up MRA was 2.4 years (1.5-3.1) for GCA and 1.6 years (1.3-3.3) for TAK.

There were 159 territories affected at the baseline visit in 41 patients [TAK: 108 territories in 26 patients, GCA: 51 territories in 15 patients]. The development of new territory involvement was infrequent and only occurred in patients with TAK (8 new lesions out of 352 baseline unaffected territories (2.3%) in 5 patients).

At follow up, existing arterial lesions improved in 25 (15.7%) territories, worsened in 6 (3.8%) territories, and stayed the same in 128 (80.5%) territories. There were no significant differences in angiographic progression of disease between the two diseases: improved - TAK 19 (17.6%), GCA 6 (11.8%); worsened - TAK 5 (4.6%), GCA 1 (1.9%); unchanged - TAK 84 (77.8%), GCA 44 (86.3%). Change in the branch arteries was more dynamic than change in the aorta(Figure).

Improvement in angiographic disease was observed in 8 (17%) patients (TAK=6, GCA=2). Worsening of disease was seen in 3 (7%) patients (TAK=2, GCA=1). In 5 (11%) patients (TAK=5, GCA=0), there were areas of improvement and other areas of worsening disease within the same patient.

Conclusion:

Dynamic change in arterial lesions is observed in patients with TAK and GCA. Improvement and worsening of arterial lesions can be observed over time, even within the same patient. This observation suggests that both local factors at the level of the artery and systemic factors (e.g. treatment response) are likely associated with angiographic progression. The development of new angiographic lesions was infrequent, and only occurred in patients with TAK. These data may inform future guideline recommendations for angiographic monitoring in LVV.

References:

N/A

Figure.

Disclosure of Interests:

None declared

OP0144 EFFECT OF TOCILIZUMAB ON VASCULAR INFLAMMATION BY 18F-FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY: A PROSPECTIVE, LONGITUDINAL STUDY

Background:

Two randomized controlled trials have demonstrated clinical efficacy of tocilizumab for the treatment of giant cell arteritis (GCA)(1, 2). In these trials, clinical and laboratory measures were used to define the outcome measures. The direct effect of tocilizumab on vascular inflammation remains poorly characterized.

Objectives:

To prospectively evaluate vascular inflammation as measured by18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in a longitudinal cohort of patients with GCA treated with tocilizumab over a several year follow-up period.

Methods:

Patients with GCA were recruited into a prospective, observational cohort. All patients fulfilled modified 1990 American College of Rheumatology (ACR) Classification Criteria for GCA. All patients underwent FDG-PET computed tomography (CT) prior to initiation of tocilizumab. A single reader reviewed all PET scans, blinded to clinical data. Qualitative assessment of FDG uptake relative to liver uptake by visual assessment (scale 0-3) was assessed in 9 arterial territories. A summary score, PET Vascular Activity Score (PETVAS), was calculated (scale 0-27).

Patients underwent imaging at 6-12 month intervals per a standardized imaging protocol. In a subset of patients in whom tocilizumab was discontinued due to established remission, a repeat FDG-PET scan was obtained within 6 months of drug discontinuation.

Change in PET activity over time was measured by linear regression. PET activity during established remission was compared to PET activity after discontinuation of tocilizumab. For some patients, tocilizumab was added to the existing treatment regimen without a substantive change in concomitant glucocorticoid dose. In a secondary analysis, patients were stratified by prednisone dosing (high dose prednisone >10mg/day prednisone, low dose prednisone ≤10mg/day prednisone during the imaging interval) to determine if tocilizumab had an effect on vascular inflammation independent of glucocorticoids.

Results:

22 patients were included in the study. All patients had clinically active disease at baseline with median baseline PETVAS 24.5 (23-27). There was a significant reduction in PETVAS over 2 years follow up (p<0.01 for linear trend) (Figure). Of note, there was continued progressive improvement in PETVAS in both year 1 and year 2 of treatment. Eight patients received concomitant high dose glucocorticoids and 14 patients remained on low dose glucocorticoids with the addition of tocilizumab. In patients who only received low dose prednisone, significant reduction in PETVAS was still observed with addition of tocilizumab (PETVAS 25.5 to 19.5, p=0.04). In a subset of 5 patients who discontinued tocilizumab due to established remission [median PETVAS 19 (17.5-22) at time of remission], a repeat FDG-PET scan within 6 months after treatment discontinuation showed worsening PET activity in 4 out of 5 patients [median PETVAS 23 (20-23)]. Two of these patients subsequently experienced a clinical disease relapse.

Conclusion:

Tocilizumab was associated with improved vascular inflammation as assessed by FDG-PET. There was continued improvement of vascular inflammation at both year 1 and year 2 of treatment, and early evidence suggests a rebound of vascular inflammation when tocilizumab was discontinued. These data provide rationale for long-term tocilizumab therapy in patients with GCA and for consideration of FDG-PET as an outcome measure in future clinical trials.

References:

[1]Stone JH, et al. N Engl J Med 2017;377:317-28.

[2]Villiger PM, et al. Lancet 2016;387:1921-7.

Figure.

XXX

Disclosure of Interests:

None declared

THU0318 PATTERNS OF CLINICAL PRESENTATION IN TAKAYASU’S ARTERITIS

Background:

Takayasu’s arteritis (TAK) is a clinically heterogenous disease. Patterns of clinical presentation in TAK at diagnosis have not been well described, and a “triphasic pattern” of constitutional symptoms evolving into vascular inflammation and fibrosis has been reported but never systematically evaluated.

Objectives:

To describe patterns of clinical presentation in TAK at diagnosis and evaluate the presence of an antecedent triphasic disease pattern in patients with TAK who presented with a major ischemic event at diagnosis.

Methods:

Patients with TAK were prospectively recruited from the National Institutes of Health (NIH) and the Vasculitis Clinical Research Consortium (VCRC). All patients fulfilled the 1990 American College of Rheumatology (ACR) Classification Criteria for TAK. Based on clinical presentation at diagnosis, patients were divided into five groups from the different stages of the triphasic pattern of disease as follows: 1) constitutional symptoms (phase I), 2) carotidynia (phase II), 3) other vascular-associated symptoms (phase II), 4) major ischemic event (phase III) defined as CVA or TIA, retinal ischemia, MI, renovascular hypertension, or mesenteric ischemia, or 5) asymptomatic. Phase II was divided into two separate groups because patients with carotidynia reportedly have a higher rate of relapsing disease.

Associated clinical characteristics were evaluated in each group and differences among groups were assessed by chi square test and Kruskal-Wallis test, as appropriate. Preceding symptoms were also assessed to determine the presence of a triphasic disease pattern.

Results:

A total of 275 patients with TAK were included (VCRC=208; NIH=67). Similar heterogeneity of clinical presentation was identified in each cohort: constitutional symptoms (8%), carotidynia (13-15%), other vascular symptoms (43-47%), major ischemic event (28-30%), and asymptomatic (2-6%). Frequency of male gender was more common in patients who presented with constitutional symptoms or were asymptomatic at diagnosis (p<0.01). Patients who presented with constitutional symptoms and major ischemic events were youngest at diagnosis. Patients in the asymptomatic group were oldest at diagnosis and often were not treated (p<0.01). Involvement of the abdominal vasculature was associated with major ischemic events and asymptomatic presentations. Major ischemic events after diagnosis were infrequent in the groups who did not present with a major ischemic event, occurring in 10-20% cases. Relapse (p<0.01) and recurrent pharyngitis preceding diagnosis (p<0.01) was most frequent in patients who presented with carotidynia.

A total of 79 patients [VCRC=59 patients, NIH=20 patients] presented with a major ischemic event. The majority of these patients (53%) reported symptoms of active disease prior to the major ischemic event. Few patients (19%) who presented with a major ischemic event reported a triphasic pattern of disease.

Conclusion:

There is heterogeneity in clinical presentation at the time of diagnosis in TAK and this heterogeneity can be used to group patients according to pattern of disease presentation. Patients do not necessarily progress sequentially through phases of disease, but the majority of patients presenting with a major ischemic event report some preceding symptoms. Data from this study demonstrate distinct subgroups within TAK and supports the concept that TAK is possibly a heterogenous collection of multiple diseases.

References:

N/A

Disclosure of Interests:

None declared

Evolutionary Dynamics of Sex Chromosomes of Paleognathous Birds

Standard models of sex chromosome evolution propose that recombination suppression leads to the degeneration of the heterogametic chromosome, as is seen for the Y chromosome in mammals and the W chromosome in most birds. Unlike other birds, paleognaths (ratites and tinamous) possess large nondegenerate regions on their sex chromosomes (PARs or pseudoautosomal regions). It remains unclear why these large PARs are retained over >100 Myr, and how this retention impacts the evolution of sex chromosomes within this system. To address this puzzle, we analyzed Z chromosome evolution and gene expression across 12 paleognaths, several of whose genomes have recently been sequenced. We confirm at the genomic level that most paleognaths retain large PARs. As in other birds, we find that all paleognaths have incomplete dosage compensation on the regions of the Z chromosome homologous to degenerated portions of the W (differentiated regions), but we find no evidence for enrichments of male-biased genes in PARs. We find limited evidence for increased evolutionary rates (faster-Z) either across the chromosome or in differentiated regions for most paleognaths with large PARs, but do recover signals of faster-Z evolution in tinamou species with mostly degenerated W chromosomes, similar to the pattern seen in neognaths. Unexpectedly, in some species, PAR-linked genes evolve faster on average than genes on autosomes, suggested by diverse genomic features to be due to reduced efficacy of selection in paleognath PARs. Our analysis shows that paleognath Z chromosomes are atypical at the genomic level, but the evolutionary forces maintaining largely homomorphic sex chromosomes in these species remain elusive.

Whole-Genome Analyses Resolve the Phylogeny of Flightless Birds (Palaeognathae) in the Presence of an Empirical Anomaly Zone

Palaeognathae represent one of the two basal lineages in modern birds, and comprise the volant (flighted) tinamous and the flightless ratites. Resolving palaeognath phylogenetic relationships has historically proved difficult, and short internal branches separating major palaeognath lineages in previous molecular phylogenies suggest that extensive incomplete lineage sorting (ILS) might have accompanied a rapid ancient divergence. Here, we investigate palaeognath relationships using genome-wide data sets of three types of noncoding nuclear markers, together totaling 20,850 loci and over 41 million base pairs of aligned sequence data. We recover a fully resolved topology placing rheas as the sister to kiwi and emu + cassowary that is congruent across marker types for two species tree methods (MP-EST and ASTRAL-II). This topology is corroborated by patterns of insertions for 4274 CR1 retroelements identified from multispecies whole-genome screening, and is robustly supported by phylogenomic subsampling analyses, with MP-EST demonstrating particularly consistent performance across subsampling replicates as compared to ASTRAL. In contrast, analyses of concatenated data supermatrices recover rheas as the sister to all other nonostrich palaeognaths, an alternative that lacks retroelement support and shows inconsistent behavior under subsampling approaches. While statistically supporting the species tree topology, conflicting patterns of retroelement insertions also occur and imply high amounts of ILS across short successive internal branches, consistent with observed patterns of gene tree heterogeneity. Coalescent simulations and topology tests indicate that the majority of observed topological incongruence among gene trees is consistent with coalescent variation rather than arising from gene tree estimation error alone, and estimated branch lengths for short successive internodes in the inferred species tree fall within the theoretical range encompassing the anomaly zone. Distributions of empirical gene trees confirm that the most common gene tree topology for each marker type differs from the species tree, signifying the existence of an empirical anomaly zone in palaeognaths.

Attenuated Fgf Signaling Underlies the Forelimb Heterochrony in the Emu Dromaius novaehollandiae

Powered flight was fundamental to the establishment and radiation of birds. However, flight has been lost multiple times throughout avian evolution. Convergent losses of flight within the ratites (flightless paleognaths, including the emu and ostrich) often coincide with reduced wings. Although there is a wealth of anatomical knowledge for several ratites, the genetic mechanisms causing these changes remain debated. Here, we use a multidisciplinary approach employing embryological, genetic, and genomic techniques to interrogate the mechanisms underlying forelimb heterochrony in emu embryos. We show that the initiation of limb formation, an epithelial to mesenchymal transition (EMT) in the lateral plate mesoderm (LPM) and myoblast migration into the LPM, occur at equivalent stages in the emu and chick. However, the emu forelimb fails to subsequently proliferate. The unique emu forelimb expression of Nkx2.5, previously associated with diminished wing development, initiates after this stage (concomitant with myoblast migration into the LPM) and is therefore unlikely to cause this developmental delay. In contrast, RNA sequencing of limb tissue reveals significantly lower Fgf10 expression in the emu forelimb. Artificially increasing Fgf10 expression in the emu LPM induces ectodermal Fgf8 expression and a limb bud. Analyzing open chromatin reveals differentially active regulatory elements near Fgf10 and Sall-1 in the emu wing, and the Sall-1 enhancer activity is dependent on a likely Fgf-mediated Ets transcription factor-binding site. Taken together, our results suggest that regulatory changes result in lower expression of Fgf10 and a concomitant failure to express genes required for limb proliferation in the early emu wing bud.

Integrating natural history collections and comparative genomics to study the genetic architecture of convergent evolution

Evolutionary convergence has been long considered primary evidence of adaptation driven by natural selection and provides opportunities to explore evolutionary repeatability and predictability. In recent years, there has been increased interest in exploring the genetic mechanisms underlying convergent evolution, in part, owing to the advent of genomic techniques. However, the current 'genomics gold rush' in studies of convergence has overshadowed the reality that most trait classifications are quite broadly defined, resulting in incomplete or potentially biased interpretations of results. Genomic studies of convergence would be greatly improved by integrating deep 'vertical', natural history knowledge with 'horizontal' knowledge focusing on the breadth of taxonomic diversity. Natural history collections have and continue to be best positioned for increasing our comprehensive understanding of phenotypic diversity, with modern practices of digitization and databasing of morphological traits providing exciting improvements in our ability to evaluate the degree of morphological convergence. Combining more detailed phenotypic data with the well-established field of genomics will enable scientists to make progress on an important goal in biology: to understand the degree to which genetic or molecular convergence is associated with phenotypic convergence. Although the fields of comparative biology or comparative genomics alone can separately reveal important insights into convergent evolution, here we suggest that the synergistic and complementary roles of natural history collection-derived phenomic data and comparative genomics methods can be particularly powerful in together elucidating the genomic basis of convergent evolution among higher taxa. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.

Convergent regulatory evolution and loss of flight in paleognathous birds

A core question in evolutionary biology is whether convergent phenotypic evolution is driven by convergent molecular changes in proteins or regulatory regions. We combined phylogenomic, developmental, and epigenomic analysis of 11 new genomes of paleognathous birds, including an extinct moa, to show that convergent evolution of regulatory regions, more so than protein-coding genes, is prevalent among developmental pathways associated with independent losses of flight. A Bayesian analysis of 284,001 conserved noncoding elements, 60,665 of which are corroborated as enhancers by open chromatin states during development, identified 2355 independent accelerations along lineages of flightless paleognaths, with functional consequences for driving gene expression in the developing forelimb. Our results suggest that the genomic landscape associated with morphological convergence in ratites has a substantial shared regulatory component.

Izumo1 and Juno: the evolutionary origins and coevolution of essential sperm-egg binding partners

Reproductive proteins are among the most rapidly evolving classes of proteins. For a subset of these, rapid evolution is driven by positive Darwinian selection despite vital, well-conserved, reproductive functions. Izumo1 is the only essential sperm-egg fusion protein currently known on mammalian sperm, and its egg receptor (Juno; formerly Folr4) was recently discovered. Male knockout mice for Izumo1 and female knockout mice for Juno are both healthy but sterile. Here, both sperm-egg binding proteins are shown to be evolving under positive selection. Within mammals, coevolution of Izumo1 and Juno is also uncovered, suggesting that similar forces have shaped the evolutionary histories of these binding partners within Mammalia. Additionally, genomic analyses reveal an ancient origin for the Izumo gene family, initially reported as conserved exclusively in mammals. Newly identified Izumo1 orthologues could serve reproductive functions in birds, fish and reptiles. Surprisingly, these same analyses support Juno's presence in mammals alone, suggesting a recent mammalian-specific duplication and neofunctionalization of the ancestral folate receptor. Despite the indispensability of their reproductive interaction, and their apparent coevolution within Mammalia, this binding pair arose through strikingly different evolutionary forces.

Positive selection in the adhesion domain of Mus sperm Adam genes through gene duplications and function-driven gene complex formations

BACKGROUND

Sperm and testes-expressed Adam genes have been shown to undergo bouts of positive selection in mammals. Despite the pervasiveness of positive selection signals, it is unclear what has driven such selective bouts. The fact that only sperm surface Adam genes show signals of positive selection within their adhesion domain has led to speculation that selection might be driven by species-specific adaptations to fertilization or sperm competition. Alternatively, duplications and neofunctionalization of Adam sperm surface genes, particularly as it is now understood in rodents, might have contributed to an acceleration of evolutionary rates and possibly adaptive diversification.

RESULTS

Here we sequenced and conducted tests of selection within the adhesion domain of sixteen known sperm-surface Adam genes among five species of the Mus genus. We find evidence of positive selection associated with all six Adam genes known to interact to form functional complexes on Mus sperm. A subset of these complex-forming sperm genes also displayed accelerated branch evolution with Adam5 evolving under positive selection. In contrast to our previous findings in primates, selective bouts within Mus sperm Adams showed no associations to proxies of sperm competition. Expanded phylogenetic analysis including sequence data from other placental mammals allowed us to uncover ancient and recent episodes of adaptive evolution.

CONCLUSIONS

The prevailing signals of rapid divergence and positive selection detected within the adhesion domain of interacting sperm Adams is driven by duplications and potential neofunctionalizations that are in some cases ancient (Adams 2, 3 and 5) or more recent (Adams 1b, 4b and 6).

Histone deacetylase inhibitors induce remission in transgenic models of therapy-resistant acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is associated with chromosomal translocations, invariably involving the retinoic acid receptor alpha (RAR alpha) gene fused to one of several distinct loci, including the PML or PLZF genes, involved in t(15;17) or t(11;17), respectively. Patients with t(15;17) APL respond well to retinoic acid (RA) and other treatments, whereas those with t(11;17) APL do not. The PML-RAR alpha and PLZF-RAR alpha fusion oncoproteins function as aberrant transcriptional repressors, in part by recruiting nuclear receptor-transcriptional corepressors and histone deacetylases (HDACs). Transgenic mice harboring the RAR alpha fusion genes develop forms of leukemia that faithfully recapitulate both the clinical features and the response to RA observed in humans with the corresponding translocations. Here, we investigated the effects of HDAC inhibitors (HDACIs) in vitro and in these animal models. In cells from PLZF-RAR alpha/RAR alpha-PLZF transgenic mice and cells harboring t(15;17), HDACIs induced apoptosis and dramatic growth inhibition, effects that could be potentiated by RA. HDACIs also increased RA-induced differentiation. HDACIs, but not RA, induced accumulation of acetylated histones. Using microarray analysis, we identified genes induced by RA, HDACIs, or both together. In combination with RA, all HDACIs tested overcame the transcriptional repression exerted by the RAR alpha fusion oncoproteins. In vivo, HDACIs induced accumulation of acetylated histones in target organs. Strikingly, this combination of agents induced leukemia remission and prolonged survival, without apparent toxic side effects.

Trial of a two-channel hearing aid (low-frequency compression-high-frequency linear amplification) with school age children

OBJECTIVE

The study was designed to investigate the efficacy of a 2-channel hearing aid with low-frequency compression and high-frequency linear amplification on a group of school-age hearing aid wearers.

DESIGN

The study was a single-center, 2-way crossover design in which 25 children (age 6 to 15 yr) were fitted with 2-channel hearing aids for 12 wk and with their own (single-channel) hearing aids for 12 wk, refitted according to published protocols. Speech perception in quiet and in noise was measured at the end of each 12 wk period; in addition, questionnaires were given to teachers, parents, and children.

RESULTS

Two-channel hearing aids showed significantly higher mean scores for speech perception in noise and significantly higher composite questionnaire scores (reflecting aspects of satisfaction and benefit). Final choice of hearing aids at the end of the study by parents and children also favored the 2-channel device.

CONCLUSIONS

The 2-channel hearing aids appear to be an acceptable management option for audiometrically suitable children. The results provide support for the 2-channel design rationale and suggest the need for further trials.

Comparison of depression in the community-dwelling and assisted-living elderly

Depressive affect in assisted living (n = 351) and community dwelling (n = 102) elderly was compared by means of the state and trait forms of Set 1 of the Depression Adjective Check Lists (DACL). Four separate analyses of covariance (age as covariate) showed the main effects of living arrangement and form to be significant on each of the four lists. Assisted living and the state form were significantly higher. Sex was not significant on any of the lists, and none of the two-way and three-way interactions reached significance. Implications of the findings for program planning for the elderly in assisted living arrangements are discussed.

Depressive disorders: distinctions in children

OBJECTIVE

The present study examined the distinctions between major depression without dysthymia, dysthymia without major depression, and double depression in child psychiatry inpatients.

METHOD

Sixty-two child inpatients, with current diagnoses of major depression and/or dysthymia, and their mothers were interviewed with the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Epidemiologic Version and the Social Adjustment Inventory for Children and Adolescents.

RESULTS

Results suggest that the relationship between the three disorders is complex and varies according to the informant and the domain under examination. Externalizing disorders were present more often in the dysthymic group compared to the major depression and double depression groups. On the other hand, the major depression and double depression groups reported higher rates of depressive symptoms. Regarding social functioning, children with major depression appeared least impaired. Child report was found to be more sensitive to distinguishing between depressive syndromes, and parents reported the most depressive symptomatology.

CONCLUSION

It appears that the presence of major depression plays an important role in the expression of depressive symptomatology and comorbidity, whereas chronicity seems to be the determining factor in social functioning.

The utility of a DSM-III-R-based checklist in screening child psychiatric patients

The Stony Brook Child Psychiatric Checklist, a parent completed rating instrument based on DSM-III-R, was used as part of a psychiatric inpatient admission evaluation. Data were collected on 63 5- to 13-year-old children. Checklist endorsements were compared with the same parent's responses to the Kiddie-Schedule for Affective Disorders and Schizophrenia for School-aged Children-Epidemiologic Version structured interview for the most frequently occurring disorders. Sensitivity scores ranged from 0.69 to 0.93. Results suggest the checklist can be useful in alerting the clinician to diagnostic areas warranting further pursuit.

Secular trends in psychiatric diagnoses of suicide victims

Post-mortem psychiatric diagnoses are compared in two cohorts of male suicides from St. Louis (1956-1957) (Robins, 1981) and San Diego (1981-1982) (Rich et al., 1986). Similar structured interviews and diagnostic criteria had been used in both assessments. Substance/alcohol abuse has remained the major diagnosis in suicides under age 60. Rates of depressive disorder alone have decreased overall, due mostly to decreased rates in the elderly. Thus, depression occurs more frequently in younger ages. Comorbid depression and substance/alcohol abuse has also increased in younger ages. Implications in terms of the so-called 'cohort effect' are discussed.

Effects of cartoons on emotionally disturbed children's social behavior in school settings

Four classes of emotionally disturbed (ED) children (20 boys and 6 girls, age: M = 8.1 yr) were exposed to six aggressive and six control cartoons. Treatment effects were assessed using direct observations of five categories of behavior during lunch and recess for baseline and the two cartoon conditions. The results revealed significantly more nonphysical aggression following the control cartoons than during baseline across setting and more physical aggression following the control cartoons relative to the aggressive cartoon and baseline conditions in the recess setting. The findings are discussed with regard to their clinical implications and comparability with other field experiments.

Effects of viewing aggressive cartoons on the behavior of learning disabled children

Forty-six learning disabled children (M = 7.6 years) were exposed to six aggressive and six control cartoons in school. Treatment effects were assessed using direct observations of five categories of social behavior. There were no main effects for condition, and neither initial aggressiveness nor gender interacted significantly with condition for any of the behaviors. There was a significant interaction of condition with IQ: the low IQ group became significantly more physically aggressive following control compared with aggressive cartoons. The results from the present study are compared with the findings from other field experiments, and their clinical relevance is discussed.