Secondary Intention Healing After Debridement for Bilateral Periorbital Necrotizing Fasciitis.

A 75-year-old male with a history of poorly controlled diabetes, hypertension, coronary artery disease, chronic obstructive pulmonary disease, and obesity presented with severe bilateral periorbital edema with necrosis and purulent discharge. Although hemodynamically stable, laboratory markers indicated systemic toxicity. Imaging showed bilateral periorbital edema extending into the frontal scalp, temporal fossa, and right orbit. Suspected to have necrotizing fasciitis, the patient underwent urgent debridement of bilateral upper and lower eyelids and was found to have postseptal extension of necrosis into the right orbit. During his hospitalization, he was treated with broad-spectrum antimicrobials and underwent a second surgery for exploration and debridement. The patient was lost to follow-up and found to have healed by secondary intention without any surgical reconstruction. Our case demonstrates not only a rare case of necrotizing fasciitis involving all 4 eyelids, but also an exceptional cosmetic and functional result after secondary intention healing.

Fatal Oedipism: A Case Report and Literature Review.

PURPOSE: To describe a unique case of a fatal self-enucleation and review previously published cases. METHODS: The authors describe a unique case of a complete unilateral self-enucleation while under the influence of drugs, which resulted in severe intracranial hemorrhages, right internal carotid artery opacification, and death. A literature review was performed by searching articles published before January 2023 in the Pubmed/MEDLINE database using the keywords "auto-enucleation or self-enucleation." Cases of self-inflicted damage to the globe without severing any connections were excluded. RESULTS: A literature review identified a total of 54 articles and 75 patients who had self-enucleated at least one globe completely (84.0%). Their average age was 37 years and 50.7% were male. At the time of auto-enucleation, 64.0% of these patients had known psychiatric disorders, and 28.0% were found to be under the influence of illicit drugs or alcohol. Auto-enucleation resulted in intracranial complications in 26.7% of cases. There has been 1 prior case, which, like the authors' case, resulted in death due to intracranial complications. However, this occurred in a patient who partially enucleated one eye after a self-inflicted injury to the fellow eye. The current case is unique as these complications resulted from a complete unilateral auto-enucleation. CONCLUSIONS: The severity of this case's presentation and outcome highlights the importance of prompt neuroimaging and a thorough assessment. Prompt psychiatric assessment and treatment are also required.

Effects of Smoking on Outcomes of Thyroid Eye Disease Treated with Teprotumumab: A Retrospective Cohort Study.

Introduction: Smoking has been demonstrated to worsen the disease process and conventional treatment outcomes of thyroid eye disease. However, the effects of smoking on outcomes of thyroid eye disease treated with the novel therapeutic teprotumumab are currently unknown. Our study compares response to teprotumumab treatment between smokers and non-smokers with thyroid eye disease. Methods: A single-center, retrospective cohort study was conducted. Inclusion criteria were patients diagnosed with thyroid eye disease who had started or completed therapy with teprotumumab at the time of our data collection. Main outcome measures included reduction in clinical activity score, diplopia, and proptosis. Results: All smokers had type 2 thyroid eye disease prior to treatment and demonstrated less improvement in diplopia, proptosis, and overall clinical activity score compared to non-smokers with thyroid eye disease. There was no significant difference between smokers and non-smokers in baseline variables (sex, thyroid stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), number of infusions completed). Data analysis revealed a statistically significant difference in proptosis reduction between non-smokers and smokers. Conclusions: Smoking is a modifiable risk factor which portends a worse response to treatment of thyroid eye disease with teprotumumab.

Diffusion-Weighted Imaging of the Orbit: A Case Series and Systematic Review.

PURPOSE: To describe the findings of diffusion-weighted imaging (DWI) for a series of orbital lesions and provide a systematic review of relevant literature. METHODS: A retrospective review of 20 patients with orbital lesions who underwent MRI with DWI at two academic institutions between 2015 and 2020 was performed. Lesion diagnosis was histopathologically confirmed except a presumed cavernous hemangioma. Echoplanar diffusion-weighted images had been acquired using 2 or 3 b values (b=0 and 1000 or b=0, 500, and 1000) at 1.5T or 3T. Lesions with significant artifacts were excluded. DWI sequences were analyzed by neuro-radiologists blinded to the diagnosis. Mean ADC values of lesions were calculated from a single region of interest. An independent two-tailed t test was used to compare categories of lesions with p < 0.05 considered significant. A systematic review of the literature was performed. RESULTS: Our study included 21 lesions. ADC values were significantly lower for malignant lesions (0.628 ± 0.125 × 10 -3 mm 2 /s) than inflammatory lesions (1.167 ± 0.381 × 10 -3 mm 2 /s) ( p < 0.001). ADC values were significantly lower for orbital lymphoma (mean 0.621 ± 0.147 × 10 -3 mm 2 /s) than idiopathic orbital inflammation (mean 1.188 ± 0.269 × 10 -3 mm 2 /s) with no overlap ( p < 0.001). CONCLUSIONS: Orbital malignancies demonstrated lower ADC values, while inflammatory processes demonstrated higher ADC values, except IgG4-related disease. DWI and ADC values differentiated idiopathic orbital inflammation from orbital lymphoma. This study highlights the role of DWI in evaluating orbital pathology.

Efficacy of vaccination against equine herpesvirus type 1 (EHV-1) infection: Systematic review and meta-analysis of randomised controlled challenge trials.

BACKGROUND: Equid herpesvirus type 1 (EHV-1) infection can cause a range of disease syndromes of variable severity that can result in a lethal outcome and restriction of horse movements, especially in the case of outbreaks involving neurological disease. Vaccination is one of the tools used to control the infection. It is widely known that vaccination is not completely effective in ensuring protection against disease caused by this virus. In fact, the real efficacy of vaccination against EHV-1 related disease has not been measured and no systematic reviews exist on this topic. OBJECTIVES: To perform a systematic review and meta-analysis on the efficacy of commercial or candidate vaccines against EHV-1 in randomised controlled trials (RCT) all of which involved experimental challenge of the test subjects. STUDY DESIGN: Systematic review and meta-analysis. METHODS: RCTs were searched using the search algorithm (([equid herpesvirus* OR equine herpesvirus* OR EHV-1]) AND vaccin*) AND (trial OR experimental OR challenge) on PubMed, Science Citation Index Expanded, Scopus, and CAB Abstracts. Where appropriate, meta-analysis was performed using RevMan 5.4. RESULTS: Eight studies were selected and were analysed for their respective characteristics and possible shortcomings. The results of RCTs revealed that there was a general improvement in the clinical and virological outcomes of EHV-1 infection following vaccination, but that the effects were very slight. The reduced beneficial effect is probably amplified by the paucity of detailed data reported in the studies that did not allow for the comparison of parameters in many of the cases analysed. MAIN LIMITATIONS: The remarkable heterogeneity and the poor quality of reporting of the selected studies. CONCLUSIONS: Meta-analysis has shown that EHV-1 vaccination generally results in a slight improvement in clinical and virological outcomes, although not to a significant extent. The cumulative results have probably been affected by the lack of information on some parameters not systematically reported in the studies. An improvement in the standard of reporting and better standardisation of the data collected would likely have improved the quality of each study and enabled more effective comparison of the studies with each other.

Pediatric cavernous sinus and superior ophthalmic vein thrombophlebitis complicated by peri-venous orbital abscesses.

Purpose: This case report documents a 13-year-old male with bilateral cavernous sinus thrombosis and left superior ophthalmic vein thrombosis secondary to sphenoid sinusitis who subsequently developed peri-venous orbital abscesses. Observations: Although the patient initially improved clinically with intravenous antibiotic therapy and therapeutic anticoagulation, his symptoms returned and repeat imaging demonstrated two well-circumscribed, rim-enhancing lesions in the left orbit concerning for abscesses. Surgical intervention revealed that these purulent collections were contiguous with the superior and inferior ophthalmic veins with the superior collection also containing hemorrhagic material. Despite aggressive management, the abscess in the inferolateral orbit recurred, requiring repeat surgical intervention. The patient was ultimately discharged on parenteral antibiotics and anticoagulation, and on outpatient follow-up, there was no evidence of recurrence. Conclusions and Importance: This case report describes a pediatric patient with bilateral cavernous sinus thrombosis who developed the rare complication of multiple peri-venous orbital abscesses despite appropriate treatment with antibiotics. The patient's complex clinical course highlights the importance of prompt repeat imaging and possible surgical intervention upon clinical changes, especially in patients with infections from the Streptococcus milleri group.

Identification of a Ruminant Origin Group B Rotavirus Associated with Diarrhea Outbreaks in Foals.

Equine rotavirus group A (ERVA) is one of the most common causes of foal diarrhea. Starting in February 2021, there was an increase in the frequency of severe watery to hemorrhagic diarrhea cases in neonatal foals in Central Kentucky. Diagnostic investigation of fecal samples failed to detect evidence of diarrhea-causing pathogens including ERVA. Based on Illumina-based metagenomic sequencing, we identified a novel equine rotavirus group B (ERVB) in fecal specimens from the affected foals in the absence of any other known enteric pathogens. Interestingly, the protein sequence of all 11 segments had greater than 96% identity with group B rotaviruses previously found in ruminants. Furthermore, phylogenetic analysis demonstrated clustering of the ERVB with group B rotaviruses of caprine and bovine strains from the USA. Subsequent analysis of 33 foal diarrheic samples by RT-qPCR identified 23 rotavirus B-positive cases (69.69%). These observations suggest that the ERVB originated from ruminants and was associated with outbreaks of neonatal foal diarrhea in the 2021 foaling season in Kentucky. Emergence of the ruminant-like group B rotavirus in foals clearly warrants further investigation due to the significant impact of the disease in neonatal foals and its economic impact on the equine industry.

Efficacy of vertical lid split versus lateral canthotomy and cantholysis in the management of orbital compartment syndrome.

Purpose: To compare the efficacy of the vertical lid split (VLS) to the standard lateral canthotomy and cantholysis (LC/C) for orbital compartment syndrome (OCS) in the cadaveric model.Methods: Simulated OCS was achieved in seven fresh frozen cadaveric orbits. Orbital pressure (OP) was monitored in one control orbit and six interventional orbits. Initial OP was recorded before three right orbits underwent lateral canthotomy with superior and inferior cantholysis, and three left orbits underwent vertical lid split of the upper and lower eyelids. In all 7 orbits, OP was recorded for a total of 16 min. The main outcome measure was the amount of OP reduction at timed intervals.Results: Beginning OP in the control orbit was 109 mmHg, and average initial OP of the LC/C and VLS orbits were 90 and 103 mmHg, respectively. The control orbit maintained high OP without intervention. One minute after LC/C, OP decreased an average of 58.7 mmHg (65.2%; range 48-65 mmHg). One minute following VLS, OP decreased an average of 63 mmHg (61.0%; range 39-102 mmHg). At 16 min, OP reduction in the LC/C orbits averaged 65.3 mmHg (72.6%; range 56-71 mmHg), and OP reduction in the VLS orbits averaged 78 mmHg (75.5%; range 54-121 mmHg). Both interventions produced a comparable reduction in OP.Conclusions: Vertical lid split was found to be as effective as LC/C in reducing OP. The technical simplicity of the VLS lends itself well to utilization by physicians who are unfamiliar with eyelid surgery.

Equine arteritis virus long-term persistence is orchestrated by CD8+ T lymphocyte transcription factors, inhibitory receptors, and the CXCL16/CXCR6 axis.

Equine arteritis virus (EAV) has the unique ability to establish long-term persistent infection in the reproductive tract of stallions and be sexually transmitted. Previous studies showed that long-term persistent infection is associated with a specific allele of the CXCL16 gene (CXCL16S) and that persistence is maintained despite the presence of local inflammatory and humoral and mucosal antibody responses. Here, we performed transcriptomic analysis of the ampullae, the primary site of EAV persistence in long-term EAV carrier stallions, to understand the molecular signatures of viral persistence. We demonstrated that the local CD8+ T lymphocyte response is predominantly orchestrated by the transcription factors eomesodermin (EOMES) and nuclear factor of activated T-cells cytoplasmic 2 (NFATC2), which is likely modulated by the upregulation of inhibitory receptors. Most importantly, EAV persistence is associated with an enhanced expression of CXCL16 and CXCR6 by infiltrating lymphocytes, providing evidence of the implication of this chemokine axis in the pathogenesis of persistent EAV infection in the stallion reproductive tract. Furthermore, we have established a link between the CXCL16 genotype and the gene expression profile in the ampullae of the stallion reproductive tract. Specifically, CXCL16 acts as a "hub" gene likely driving a specific transcriptional network. The findings herein are novel and strongly suggest that RNA viruses such as EAV could exploit the CXCL16/CXCR6 axis in order to modulate local inflammatory and immune responses in the male reproductive tract by inducing a dysfunctional CD8+ T lymphocyte response and unique lymphocyte homing in the reproductive tract.

Post-operative epiphora following the transcutaneous medial canthal incision.

PURPOSE: The safety profile of the transcutaneous medial canthal incision for access to the medial orbit is assessed with a focus on the risk of post-operative iatrogenic epiphora. METHODS: A retrospective chart review of patients undergoing medial orbitotomy via the transcutaneous medial canthal incision was performed. Patients with a minimum of 3 months of follow-up were included and post-operative complications were assessed and characterized. RESULTS: One-hundred-fifty patients were included in the study. A total of 4 complications were identified, including one each of the following: nasolacrimal duct obstruction, hypertrophic scar, suture granuloma and soft tissue infection. Only the nasolacrimal duct obstruction required surgical intervention. DISCUSSION: Access to the medial orbit has been achieved through a variety of approaches, each with their own benefits and risk profile. The transcaruncular approach has increased in usage as a means to avoid a visible cutaneous scar and decrease the risk of iatrogenic epiphora, however, there are specific patients who may have relative contraindications to this approach. The current study demonstrates the low risk profile of the transcutaneous medial canthal incision, specifically the minimal risk of iatrogenic damage to the nasolacrimal outflow system. This approach is another useful tool which orbit surgeons should be familiar with to offer as an option to patients requiring medial orbitotomy.

Intracapsular hemorrhage rates in non-fixated nylon sheet orbital implants for orbital fracture management.

PURPOSE: To examine the incidence of intracapsular hemorrhage in orbital fracture repair with non-fixated nylon sheet implants. METHODS: A retrospective chart review of 227 patients presenting from January 2013 to December 2016 for orbital fracture repair with nylon sheet implants. RESULTS: Of the 331 orbital fractures repaired over 4 years, a total of 227 met inclusion criteria. The average implant thickness was 0.38 mm and no implants were fixated. Four total implants (1.8%) were removed due to complications; one each secondary to exploration for ongoing postoperative diplopia, immediate post-operative orbital hemorrhage, a cystic mass anterior to the implant, and pain. There were no cases of intracapsular hemorrhage nor infection for any of the 227 patients over 4 years. CONCLUSIONS: To the authors knowledge, this represents the largest case series to date to assess the rate of intracapsular hemorrhage in non-fixated nylon sheet orbital implants. In the 227 cases reviewed over a 4-year period, there were no cases of intracapsular hemorrhage. This suggests a much lower complication rate than previously reported. PRéCIS: A case series of 227 patients who underwent orbital fracture repair with non-fixated nylon sheet implants.

Intrahost Selection Pressure Drives Equine Arteritis Virus Evolution during Persistent Infection in the Stallion Reproductive Tract.

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a reproductive and respiratory disease of horses. Following natural infection, 10 to 70% of infected stallions can become carriers of EAV and continue to shed virus in the semen. In this study, sequential viruses isolated from nasal secretions, buffy coat cells, and semen of seven experimentally infected and two naturally infected EAV carrier stallions were deep sequenced to elucidate the intrahost microevolutionary process after a single transmission event. Analysis of variants from nasal secretions and buffy coat cells lacked extensive positive selection; however, characteristics of the mutant spectra were different in the two sample types. In contrast, the initial semen virus populations during acute infection have undergone a selective bottleneck, as reflected by the reduction in population size and diversifying selection at multiple sites in the viral genome. Furthermore, during persistent infection, extensive genome-wide purifying selection shaped variant diversity in the stallion reproductive tract. Overall, the nonstochastic nature of EAV evolution during persistent infection was driven by active intrahost selection pressure. Among the open reading frames within the viral genome, ORF3, ORF5, and the nsp2-coding region of ORF1a accumulated the majority of nucleotide substitutions during persistence, with ORF3 and ORF5 having the highest intrahost evolutionary rates. The findings presented here provide a novel insight into the evolutionary mechanisms of EAV and identified critical regions of the viral genome likely associated with the establishment and maintenance of persistent infection in the stallion reproductive tract.IMPORTANCE EAV can persist in the reproductive tract of infected stallions, and consequently, long-term carrier stallions constitute its sole natural reservoir. Previous studies demonstrated that the ampullae of the vas deferens are the primary site of viral persistence in the stallion reproductive tract and the persistence is associated with a significant inflammatory response that is unable to clear the infection. This is the first study that describes EAV full-length genomic evolution during acute and long-term persistent infection in the stallion reproductive tract using next-generation sequencing and contemporary sequence analysis techniques. The data provide novel insight into the intrahost evolution of EAV during acute and persistent infection and demonstrate that persistent infection is characterized by extensive genome-wide purifying selection and a nonstochastic evolutionary pattern mediated by intrahost selective pressure, with important nucleotide substitutions occurring in ORF1a (region encoding nsp2), ORF3, and ORF5.

Masquerading dacryocystitis.

Intravascular papillary endothelial hyperplasia (IPEH), otherwise known as Masson's tumor, is a benign lesion of the skin with no known malignant transformations reported. It is considered a non-neoplastic lesion, as it is reactive to some vascular insult, usually a thrombus in a vein leading to vascular endothelial cell proliferation. Masson's tumor typically presents as a slow-growing, indolent lesion commonly affecting the head, neck and arms with a female predominance. It comprises ~2% of all malignant and non-malignant vascular tumors of the skin and subcutaneous tissue. We are presenting the first case of Masson's tumor of the right medial canthal subcutaneous tissue, masquerading as dacryocystitis.

Downregulation of MicroRNA eca-mir-128 in Seminal Exosomes and Enhanced Expression of CXCL16 in the Stallion Reproductive Tract Are Associated with Long-Term Persistence of Equine Arteritis Virus.

Equine arteritis virus (EAV) can establish long-term persistent infection in the reproductive tract of stallions and is shed in the semen. Previous studies showed that long-term persistence is associated with a specific allele of the CXCL16 gene (CXCL16S) and that persistent infection is maintained despite the presence of a local inflammatory and humoral and mucosal antibody responses. In this study, we demonstrated that equine seminal exosomes (SEs) are enriched in a small subset of microRNAs (miRNAs). Most importantly, we demonstrated that long-term EAV persistence is associated with the downregulation of an SE-associated miRNA (eca-mir-128) and with an enhanced expression of CXCL16 in the reproductive tract, a putative target of eca-mir-128. The findings presented here suggest that SE eca-mir-128 is implicated in the regulation of the CXCL16/CXCR6 axis in the reproductive tract of persistently infected stallions, a chemokine axis strongly implicated in EAV persistence. This is a novel finding and warrants further investigation to identify its specific mechanism in modulating the CXCL16/CXCR6 axis in the reproductive tract of the EAV long-term carrier stallion.IMPORTANCE Equine arteritis virus (EAV) has the ability to establish long-term persistent infection in the stallion reproductive tract and to be shed in semen, which jeopardizes its worldwide control. Currently, the molecular mechanisms of viral persistence are being unraveled, and these are essential for the development of effective therapeutics to eliminate persistent infection. Recently, it has been determined that long-term persistence is associated with a specific allele of the CXCL16 gene (CXCL16S) and is maintained despite induction of local inflammatory, humoral, and mucosal antibody responses. This study demonstrated that long-term persistence is associated with the downregulation of seminal exosome miRNA eca-mir-128 and enhanced expression of its putative target, CXCL16, in the reproductive tract. For the first time, this study suggests complex interactions between eca-mir-128 and cellular elements at the site of EAV persistence and implicates this miRNA in the regulation of the CXCL16/CXCR6 axis in the reproductive tract during long-term persistence.

Endoscopically assisted Crawford tube placement results in shorter general anesthesia times in pediatric patients.

BACKGROUND: Crawford tube placement is commonly used to achieve patency of nasolacrimal ducts for epiphora secondary to nasolacrimal duct obstruction. The nasal passages of pediatric patients are narrower than adults, and the result is a relatively higher risk of intranasal complications (e.g., synechiae, bleeding) with Crawford tube placement. There is evidence that general anesthesia may negatively affect the neurocognitive function and behavioral development of children, which prompts efforts to decrease operation times for potential health benefits and also potentially to reduce health care costs. Analysis of research reports supports the use of nasal endoscopy to reduce intranasal complications with Crawford tube placement; however, no publications currently address the effect of nasal endoscopy concurrent with Crawford tube placement on operative times on pediatric patients or the resulting effects on health care costs. OBJECTIVE: To determine the difference in procedure time and cost between Crawford tubes placed traditionally and those placed with endoscopic assistance in pediatric patients. METHODS: A chart review was performed from January 1, 2011 to December 31, 2016 for cases using CPT codes 68815 or 31231. Within this group of patients, the patient in whom nasal endoscopy was performed were placed in the "endoscopic" group and the patients without endoscopy were placed in the "traditional" group. Procedure times were noted, and the t-test was performed to examine for any statistically significant difference in operative times. Estimates of anesthesia cost savings were made. We identified 24 patients in the traditional group and 7 patients in the endoscopic group. RESULTS: The average operative time for the traditional group was 27.3 minutes compared with 14.0 minutes for the endoscopic group (p = 0.02). The cost comparison data revealed no significant difference with the traditional group averaging $9369 per procedure and the endoscopic group averaging $8891 (p = 0.51). CONCLUSION: An endoscopically assisted Crawford tube placement resulted in patients who had less time under general anesthesia compared with the traditional technique at no difference in cost.

Surgical preferences in the management of recalcitrant endophthalmitis.

To assess the practice patterns of current members of the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) in the treatment of medically refractive endophthalmitis (MRE). A 17-question survey included the procedure of choice for MRE, the preferred type of orbital implant, the timing of implant placement, and the incidence of postoperative complications. 107 ASOPRS members participated in the study. In the setting of MRE, 72% preferred evisceration versus 28% who preferred enucleation. Fifty-nine percent of responders preferred enucleation if the MRE extended to orbital tissues versus 27% who would eviscerate. Among those that would place an orbital implant at the initial surgery, 65% would do so during an enucleation and 58% would do so during an evisceration. If an orbital implant was placed at the initial surgery, 52% of responders preferred a silicone implant, while 17% preferred hydroxyapatite implant. A minority of responders (6%) reported "yes" to ever having infectious complications after primary enucleation, compared to 10% after primary evisceration. Overall, 12% of responders noted more frequent complications (other than infectious) when an enucleation was performed compared to 5% for eviscerations. Current opinions on the surgical management of MRE show a trend toward evisceration, with 65% of ASOPRS respondents placing an orbital implant at the time of an enucleation and 58% at the time of an evisceration. Enucleation was preferred when involvement of orbital tissues was apparent. Both evisceration and enucleation remain a viable treatment option for MRE. The most appropriate initial approach is best determined by careful patient selection and informed decision-making by the patient.

Equine Arteritis Virus Elicits a Mucosal Antibody Response in the Reproductive Tract of Persistently Infected Stallions.

Equine arteritis virus (EAV) has the ability to establish persistent infection in the reproductive tract of the stallion (carrier) and is continuously shed in its semen. We have recently demonstrated that EAV persists within stromal cells and a subset of lymphocytes in the stallion accessory sex glands in the presence of a significant local inflammatory response. In the present study, we demonstrated that EAV elicits a mucosal antibody response in the reproductive tract during persistent infection with homing of plasma cells into accessory sex glands. The EAV-specific immunoglobulin isotypes in seminal plasma included IgA, IgG1, IgG3/5, and IgG4/7. Interestingly, seminal plasma IgG1 and IgG4/7 possessed virus-neutralizing activity, while seminal plasma IgA and IgG3/5 did not. However, virus-neutralizing IgG1 and IgG4/7 in seminal plasma were not effective in preventing viral infectivity. In addition, the serological response was primarily mediated by virus-specific IgM and IgG1, while virus-specific serum IgA, IgG3/5, IgG4/7, and IgG6 isotype responses were not detected. This is the first report characterizing the immunoglobulin isotypes in equine serum and seminal plasma in response to EAV infection. The findings presented herein suggest that while a broader immunoglobulin isotype diversity is elicited in seminal plasma, EAV has the ability to persist in the reproductive tract, in spite of local mucosal antibody and inflammatory responses. This study provides further evidence that EAV employs complex immune evasion mechanisms during persistence in the reproductive tract that warrant further investigation.

Retrospective chart review of the use of imaging and biopsy in the diagnosis of optic nerve sheath meningiomas and intra-conal orbital lymphomas at a single institution.

Optic nerve sheath meningiomas (ONSM) and intra-conal orbital lymphomas are common entities on the differential of a retrobulbar optic nerve involving space-occupying lesion. In this study, we compare the pre-surgical diagnosis, based on clinical presentation and neuroimaging, to the surgical pathology results of intra-conal orbital lymphomas and ONSM. This is an IRB approved retrospective chart review of orbital lymphomas and optic nerve sheath meningiomas biopsied by a single surgeon over a 4-year period at a single institution. Pre-surgical diagnosis and surgical pathology were compared. Fifteen cases of orbital lymphoma were identified. Fourteen were excluded based on extra-conal location. The single histologically confirmed intra-conal orbital lymphoma had a pre-surgical diagnosis of ONSM. Four cases of optic nerve sheath meningioma were identified. Three of the 4 cases of histologically confirmed ONSM had a pre-surgical diagnosis of ONSM. One of the 4 had a pre-surgical diagnosis of lymphoma. Diagnosis based on surgical pathology differed from the pre-surgical diagnosis in 2 out of 5 cases showing that clinical diagnosis does not always correlate with histologic diagnosis. Although both diseases are typically managed with radiation therapy, the treatment dosage and systemic disease implications are very different. These findings emphasis the importance of biopsy in the diagnosis of orbital lesions surrounding the optic nerve.

Equine Arteritis Virus Has Specific Tropism for Stromal Cells and CD8+ T and CD21+ B Lymphocytes but Not for Glandular Epithelium at the Primary Site of Persistent Infection in the Stallion Reproductive Tract.

Equine arteritis virus (EAV) has a global impact on the equine industry as the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of equids. A distinctive feature of EAV infection is that it establishes long-term persistent infection in 10 to 70% of infected stallions (carriers). In these stallions, EAV is detectable only in the reproductive tract, and viral persistence occurs despite the presence of high serum neutralizing antibody titers. Carrier stallions constitute the natural reservoir of the virus as they continuously shed EAV in their semen. Although the accessory sex glands have been implicated as the primary sites of EAV persistence, the viral host cell tropism and whether viral replication in carrier stallions occurs in the presence or absence of host inflammatory responses remain unknown. In this study, dual immunohistochemical and immunofluorescence techniques were employed to unequivocally demonstrate that the ampulla is the main EAV tissue reservoir rather than immunologically privileged tissues (i.e., testes). Furthermore, we demonstrate that EAV has specific tropism for stromal cells (fibrocytes and possibly tissue macrophages) and CD8+ T and CD21+ B lymphocytes but not glandular epithelium. Persistent EAV infection is associated with moderate, multifocal lymphoplasmacytic ampullitis comprising clusters of B (CD21+) lymphocytes and significant infiltration of T (CD3+, CD4+, CD8+, and CD25+) lymphocytes, tissue macrophages, and dendritic cells (Iba-1+ and CD83+), with a small number of tissue macrophages expressing CD163 and CD204 scavenger receptors. This study suggests that EAV employs complex immune evasion mechanisms that warrant further investigation.IMPORTANCE The major challenge for the worldwide control of EAV is that this virus has the distinctive ability to establish persistent infection in the stallion's reproductive tract as a mechanism to ensure its maintenance in equid populations. Therefore, the precise identification of tissue and cellular tropism of EAV is critical for understanding the molecular basis of viral persistence and for development of improved prophylactic or treatment strategies. This study significantly enhances our understanding of the EAV carrier state in stallions by unequivocally identifying the ampullae as the primary sites of viral persistence, combined with the fact that persistence involves continuous viral replication in fibrocytes (possibly including tissue macrophages) and T and B lymphocytes in the presence of detectable inflammatory responses, suggesting the involvement of complex viral mechanisms of immune evasion. Therefore, EAV persistence provides a powerful new natural animal model to study RNA virus persistence in the male reproductive tract.

Allelic Variation in CXCL16 Determines CD3+ T Lymphocyte Susceptibility to Equine Arteritis Virus Infection and Establishment of Long-Term Carrier State in the Stallion.

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of horses and other equid species. Following natural infection, 10-70% of the infected stallions can become persistently infected and continue to shed EAV in their semen for periods ranging from several months to life. Recently, we reported that some stallions possess a subpopulation(s) of CD3+ T lymphocytes that are susceptible to in vitro EAV infection and that this phenotypic trait is associated with long-term carrier status following exposure to the virus. In contrast, stallions not possessing the CD3+ T lymphocyte susceptible phenotype are at less risk of becoming long-term virus carriers. A genome wide association study (GWAS) using the Illumina Equine SNP50 chip revealed that the ability of EAV to infect CD3+ T lymphocytes and establish long-term carrier status in stallions correlated with a region within equine chromosome 11. Here we identified the gene and mutations responsible for these phenotypes. Specifically, the work implicated three allelic variants of the equine orthologue of CXCL16 (EqCXCL16) that differ by four non-synonymous nucleotide substitutions (XM_00154756; c.715 A → T, c.801 G → C, c.804 T → A/G, c.810 G → A) within exon 1. This resulted in four amino acid changes with EqCXCL16S (XP_001504806.1) having Phe, His, Ile and Lys as compared to EqCXL16R having Tyr, Asp, Phe, and Glu at 40, 49, 50, and 52, respectively. Two alleles (EqCXCL16Sa, EqCXCL16Sb) encoded identical protein products that correlated strongly with long-term EAV persistence in stallions (P<0.000001) and are required for in vitro CD3+ T lymphocyte susceptibility to EAV infection. The third (EqCXCL16R) was associated with in vitro CD3+ T lymphocyte resistance to EAV infection and a significantly lower probability for establishment of the long-term carrier state (viral persistence) in the male reproductive tract. EqCXCL16Sa and EqCXCL16Sb exert a dominant mode of inheritance. Most importantly, the protein isoform EqCXCL16S but not EqCXCL16R can function as an EAV cellular receptor. Although both molecules have equal chemoattractant potential, EqCXCL16S has significantly higher scavenger receptor and adhesion properties compared to EqCXCL16R.