Case Report: Dynamic overlap of melanoma, sarcoidosis, and targeted therapy for BRAF-mutant melanoma

Targeted therapies, including BRAF and MEK inhibitors, are valuable treatment options for patients with unresectable or metastatic BRAF V600-mutant melanoma. With the improvement in survival seen with modern melanoma therapeutics, clinicians are learning the variable patterns associated with extended clinical courses. Sarcoidosis is characterized by non-caseating granulomatous inflammation of unknown etiology, often presenting with cutaneous, lung, or lymph node involvement. There is a known association between sarcoidosis and melanoma, and sarcoidosis is increasingly seen and described in the setting of anti-melanoma therapy. The challenge for clinicians is to differentiate between sarcoid-related and malignancy-related findings, which may follow a variable course over years. We present two cases of BRAF and MEK inhibitor-related sarcoidosis in patients with melanoma and review the literature. The dynamic nature of the clinical and radiographic findings impacted patient management and clinical decisions for years of their treatment course.

Relevance of the Updated Recursive Partitioning Analysis (U-RPA) Classification in the Contemporary Care of Patients with Brain Metastases

Patients with brain metastases (BMETS) need information about the prognosis and potential value of treatment options to make informed therapeutic decisions, but tools to predict survival in contemporary practice are scarce. We propose an Updated Recursive Partitioning Analysis (U-RPA) instrument to predict survival and benefit from brain-directed treatment (BDT) of contemporary patients. This was a retrospective analysis of patients with BMETS treated between 2017 and 2019. With survival as the primary endpoint, we calculated the U-RPA and generated estimates using Kaplan-Meier curves and hazard ratios. Of 862 eligible patients, 752 received BDT and 110 received best supportive care (BSC). Median overall survival with BDT and BSC was 9.3 and 1.3 months, respectively. Patients in RPA class 1, 2A, 2B and 3 who underwent BDT had median survival of 28.1, 14.7, 7.6 and 3.3 months, respectively. The median survival for patients in RPA 3 who received BDT (n = 147), WBRT (n = 79) and SRS (n = 54) was 3.3, 2.9 and 4.1 months, respectively. The U-RPA defines prognosis estimates, independent of tumor type and treatment modality, which can assist to make value-based care treatment decisions. The prognosis for patients in U-RPA class 2B and 3 remains poor, with consideration for early palliative care involvement in these cases.

Multicenter Experience with Neoadjuvant Therapy in Melanoma Highlights Heterogeneity in Contemporary Practice

OBJECTIVE

To determine the feasibility and impact of neoadjuvant therapy (NT) in patients who present with advanced melanoma amenable to surgical resection.

SUMMARY BACKGROUND DATA

Given current effective systemic therapy for melanoma, the use of NT is being explored in patients with advanced melanoma with disease amenable to surgical resection.

METHODS

Prospective data from 3 institutions was obtained in patients with clinically evident Stage III/IV melanoma who underwent NT. The primary objective was to compare recurrence-free survival between patients who had pathologic complete response (pCR) to those with persistent disease.

RESULTS

NT was offered to 45 patients, with 43 patients initiating various NT regimens including PD-1 antagonist (PD-1) therapy (N = 16), PD-1 plus ipilimumab (N = 10), BRAF/MEK inhibitor therapy (N = 14), a combination of those three (N = 1), and talimogene laherparepvec (TVEC) (N = 2). Thirty-two (74.1%) patients underwent surgery whereas 11 patients did not undergo surgery for these reasons: clinical CR (N = 7), progressive disease not amenable to resection (N = 3), and ongoing therapy (N = 1). 12 of 32 patients (37.5%) had pCR with these therapies: PD-1 (N = 4), PD-1 plus ipilimumab (N = 2), BRAF/MEK (N = 4), combination (N = 1), and TVEC (N = 1). At median follow-up of 16.4 months there was only 1 recurrence in the pCR group and patients with a pCR had significantly improved recurrence-free survival compared to patients without pCR (p = 0.004).

CONCLUSIONS

Despite variability in NT regimens across institutions, NT for melanoma is feasible and associated with improved prognosis in patients who achieve a pCR. Maximizing rates of pCR could improve prognosis for patients with advanced melanoma.

PD-L1 and MHC Class I Expression in High-grade Ovarian Cancers, Including Platinum-resistant Recurrences Treated With Checkpoint Inhibitor Therapy

Immune-modulating therapies targeting the programmed cell death-1/programmed cell death ligand-1 (PD-L1) immunosuppressive system have been used successfully in many solid tumor types. There is evidence that biomarkers such as PD-L1 and major histocompatibility complex (MHC) class I help identify candidates for anti-programmed cell death-1/PD-L1 checkpoint inhibition, though the evidence is limited in ovarian malignancies. PD-L1 and MHC Class I immunostaining was performed on pretreatment whole tissue sections in 30 cases of high-grade ovarian carcinoma. The PD-L1 combined positive score was calculated (a score of ≥1 is considered positive). MHC class I status was categorized as an intact or subclonal loss. In patients who received immunotherapy, drug response was assessed using RECIST criteria. PD-L1 was positive in 26 of 30 cases (87%; combined positive score: 1 to 100). Seven of 30 patients showed subclonal loss of MHC class I (23%), and this occurred in both PD-L1 negative (3/4; 75%) and PD-L1 positive (4/26; 15%) cases. Only 1 of 17 patients who received immunotherapy in the setting of a platinum-resistant recurrence responded to the addition of immunotherapy, and all 17 died of disease. In the setting of recurrent disease, patients did not respond to immunotherapy regardless of PD-L1/MHC class I status, suggesting that these immunostains may not be effective predictive biomarkers in this setting. Subclonal loss of expression of MHC class I occurs in ovarian carcinoma, including in PD-L1 positive cases, suggesting that the 2 pathways of immune evasion may not be mutually exclusive and that it may be important to interrogate MHC class I status in PD-L1 positive tumors to identify additional immune evasion mechanisms in these tumors.

Phase I/II clinical trial of a helper peptide vaccine plus PD-1 blockade in PD-1 antibody-naïve and PD-1 antibody-experienced patients with melanoma (MEL64)

BACKGROUND

A vaccine containing 6 melanoma-associated peptides to stimulate helper T cells (6MHP) is safe, immunogenic, and clinically active. A phase I/II trial was designed to evaluate safety and immunogenicity of 6MHP vaccines plus programmed death 1 (PD-1) blockade.

PARTICIPANTS AND METHODS

Participants with advanced melanoma received 6MHP vaccines in an incomplete Freund's adjuvant (6 vaccines over 12 weeks). Pembrolizumab was administered intravenously every 3 weeks. Tumor biopsies at baseline and day 22 were analyzed by multiplex immunohistochemistry. Primary end points were safety (Common Terminology Criteria for Adverse Events V.4.03) and immunogenicity (ex vivo interferon-γ ELISpot assay). Additional end points included changes in the tumor microenvironment (TME) and clinical outcomes.

RESULTS

Twenty-two eligible participants were treated: 6 naïve to PD-1 antibody (Ab) and 16 PD-1 Ab-experienced. Median follow-up was 24.4 months. Most common treatment-related adverse events (any grade) included injection site reactions, fatigue, anemia, lymphopenia, fever, elevated aspartate aminotransferase, pruritus, and rash. Treatment-related dose-limiting toxicities were observed in 3 (14%) participants, which did not cross the study safety bound. A high durable T cell response (Rsp) to 6MHP was detected in only one participant, but twofold T cell Rsps to 6MHP were detected in 7/22 (32%; 90% CI (16% to 52%)) by week 13. Objective clinical responses were observed in 23% (1 complete response, 4 partial responses), including 4/6 PD-1 Ab-naïve (67%) and 1/16 PD-1 Ab-experienced (6%). Overall survival (OS) was longer for PD-1 Ab-naïve than Ab-experienced participants (HR 6.3 (90% CI (2.1 to 28.7)). In landmark analyses at 13 weeks, OS was also longer for those with T cell Rsps (HR 6.5 (90% CI (2.1 to 29.2)) and for those with objective clinical responses. TME evaluation revealed increased densities of CD8+ T cells, CD20+ B cells, and Tbet+ cells by day 22.

CONCLUSIONS

Treatment with the 6MHP vaccine plus pembrolizumab was safe, increased intratumoral lymphocytes, and induced T cell Rsps associated with prolonged OS. The low T cell Rsp rate in PD-1 Ab-experienced participants corroborates prior murine studies that caution against delaying cancer vaccines until after PD-1 blockade. The promising objective response rate and OS in PD-1 Ab-naïve participants support consideration of a larger study in that setting.

Outcomes From Cytotoxic Chemotherapy Following Progression on Immunotherapy in Metastatic Melanoma: An Institutional Case-Series

Introduction

The role of chemotherapy in the management of advanced melanoma is limited due to low response rates and short survival. Improved outcomes to chemotherapy administered after immunotherapy for metastatic melanoma and other solid tumors have been reported. We studied the outcomes of subjects treated at the University of Virginia (UVA) with chemotherapy following progression on prior systemic immunotherapy and compared the results with the existing literature.

Materials and Methods

Subjects were identified through an institutional database of patients treated with immunotherapy at UVA. Demographic, pathologic and clinical factors were collected, along with dates of therapy, investigator-assessed best response as per Response Evaluation Criteria for Solid Tumors version 1.1 and dates of death or last follow up. Kaplan-Meier survival estimates and log-rank tests were used to perform time to event analysis of progression free survival and overall survival.

Results

Forty-five patients were identified who met the inclusion criteria including 24 men and 21 women with a median age of 61 years. All patients had received at least one line of immunotherapy including 64.4% with prior anti-PD1 treatment. The cytotoxic chemotherapy regimens used included carboplatin with paclitaxel (55.6%), temozolomide (31.1%) and nab-paclitaxel (13.3%). The overall response rate for cytotoxic chemotherapy 22.2% and the disease control rate was 35.6%. The median progression-free survival was 1.7 months and median overall survival was 4.7 months. Nineteen (42.2%) patients survived greater than 6 months and seven (15.5%) patients survived over 12 months. Fourteen patients were able to proceed to further therapy.

Discussion

Our results reveal that receipt of immunotherapy prior to chemotherapy for metastatic melanoma does not appear to improve the benefit of chemotherapy. The palliation of symptoms, maintenance of performance status and disease control may be valuable for some patients during this time of robust research and discovery for metastatic melanoma.

Multiple evanescent white dot syndrome-like reaction associated with ipilimumab and nivolumab immune checkpoint inhibitor therapy for metastasis of choroidal melanoma

PURPOSE

To present a rare case of multiple evanescent white dot syndrome (MEWDS)-like presentation associated with immune checkpoint inhibitor therapy for metastatic choroidal melanoma.

OBSERVATIONS

A 67-year-old non-myopic Caucasian female presented with bilateral worsening vision, flashes, and floaters after receiving two doses of ipilimumab and nivolumab for metastatic class 2 peripheral choroidal melanoma. Fundus imaging of the right eye revealed hypopigmented, extra-foveal scattered chorioretinal lesions with foveal granularity. Fluorescein angiogram and autofluorescence of the right eye demonstrated corresponding hyperfluorescent and hyperautofluorescent lesions in a wreath-like configuration. Optical coherence tomography of the right eye revealed subretinal fluid. Due to concurrent systemic side effects, checkpoint inhibitor therapy was paused and the patient was started on oral prednisone. At her one month follow up visit, her vision in her right eye returned to baseline and subretinal fluid resolved.

CONCLUSIONS

This is the first reported case of a MEWDS-like chorioretinopathy after two cycles of ipilimumab/nivolumab therapy for metastatic choroidal melanoma. As immune checkpoint inhibitor therapy is still an evolving field, more research is needed to characterize ocular side effect profiles of these agents.

A phase 1 study of NY-ESO-1 vaccine + anti-CTLA4 antibody Ipilimumab (IPI) in patients with unresectable or metastatic melanoma

Ipilimumab (IPI) can enhance immunity to the cancer-testis antigen NY-ESO-1. A clinical trial was designed to assess safety, immunogenicity, and clinical responses with IPI + NY-ESO-1 vaccines and effects on the tumor microenvironment (TME). Patients with measurable NY-ESO-1⁺ tumors were enrolled among three arms: A) IPI + NY-ESO-1 protein + poly-ICLC (pICLC) + incomplete Freund’s adjuvant (IFA); B) IPI + NY-ESO-1 overlapping long peptides (OLP) + pICLC + IFA; and C) IPI + NY-ESO-1 OLP + pICLC. Clinical responses were assessed by irRC. T cell and Ab responses were assessed by ex vivo IFN-gamma ELIspot and ELISA. Tumor biopsies pre- and post-treatment were evaluated for immune infiltrates. Eight patients were enrolled: 5, 2, and 1 in Arms A-C, respectively. There were no DLTs. Best clinical responses were SD (4) and PD (4). T-cell and antibody (Ab) responses to NY-ESO-1 were detected in 6 (75%) and 7 (88%) patients, respectively, and were associated with SD. The breadth of Ab responses was greater for patients with SD than PD (p = .036). For five patients evaluable in the TME, treatment was associated with increases in proliferating (Ki67⁺) CD8⁺ T cells and decreases in RORγt⁺ CD4⁺ T cells. T cell densities increased for those with SD. Detection of T cell responses to NY-ESO-1 ex vivo in most patients suggests that IPI may have enhanced those responses. Proliferating intratumoral CD8⁺ T cells increased after vaccination plus IPI suggesting favorable impact of IPI plus NY-ESO-1 vaccines on the TME.

List of Abbreviations: Ab = antibody; CTCAE = NCI Common Terminology Criteria for Adverse Events; DHFR/DHRP = dihydrofolate reductase; DLT = Dose-limiting toxicity; ELISA = enzyme-linked immunosorbent assay; IFA = incomplete Freund’s adjuvant (Montanide ISA-51); IFNγ = Interferon gamma; IPI = Ipilimumab; irRC = immune-related response criteria; mIFH = multispectral immunofluorescence histology; OLP = NY-ESO-1 overlapping long peptides; PBMC = peripheral blood mononuclear cells; PD = Progressive disease; pICLC = poly-ICLC (Hiltonol), a TLR3/MDA-5 agonist; RLT = Regimen-limiting Toxicity; ROI = regions of interest; RT = room temperature; SAE = serious adverse event; SD = stable disease; TEAE = treatment-emergent adverse events; TLR = toll-like receptor; TME = tumor microenvironment; TRAE = treatment-related adverse events.

Trial to evaluate the immunogenicity and safety of a melanoma helper peptide vaccine plus incomplete Freund's adjuvant, cyclophosphamide, and polyICLC (Mel63)

Background

Peptide vaccines designed to stimulate melanoma-reactive CD4⁺ T cells can induce T cell and antibody (Ab) responses, associated with enhanced overall survival. We hypothesized that adding toll-like receptor 3 agonist polyICLC to an incomplete Freund’s adjuvant (IFA) would be safe and would support strong, durable CD4⁺ T cell and Ab responses. We also hypothesized that oral low-dose metronomic cyclophosphamide (mCy) would be safe, would reduce circulating regulatory T cells (T-regs) and would further enhance immunogenicity.

Participants and methods

An adaptive design based on toxicity and durable CD4+ T cell immune response (dRsp) was used to assign participants with resected stage IIA-IV melanoma to one of four study regimens. The regimens included a vaccine comprising six melanoma peptides restricted by Class II MHC (6MHP) in an emulsion with IFA alone (Arm A), with IFA plus systemic mCy (Arm B), with IFA+ local polyICLC (Arm C), or with IFA+ polyICLC+ mCy (Arm D). Toxicities were recorded (CTCAE V.4.03). T cell responses were measured by interferon γ ELIspot assay ex vivo. Serum Ab responses to 6MHP were measured by ELISA. Circulating T-regs were assessed by flow cytometry.

Results

Forty-eight eligible participants were enrolled and treated. Early data on safety and dRsp favored enrollment on arm D. Total enrollment on Arms A-D were 3, 7, 6, and 32, respectively. Treatment-related dose-limiting toxicities (DLTs) were observed in 1/7 (14%) participants on arm B and 2/32 (6%) on arm D. None exceeded the 25% DLT threshold for early closure to enrollment for any arm. Strong durable T cell responses to 6MHP were detected ex vivo in 0%, 29%, 67%, and 47% of participants on arms A-D, respectively. IgG Ab responses were greatest for arms C and D. Circulating T-regs frequencies were not altered by mCy.

Conclusions

6MHP vaccines administered with IFA, polyICLC, and mCy were well tolerated. The dRsp rate for arm D of 47% (90% CI 32 to 63) exceeded the 18% (90% CI 11 to 26) rate previously observed with 6MHP in IFA alone. Vaccination with IFA+ polyICLC (arm C) also showed promise for enhancing T cell and Ab responses.

Severe combined cardiac and neuromuscular toxicity from immune checkpoint blockade: an institutional case series

Background

Immune checkpoint inhibition is part of standard systemic management for many advanced malignancies. Toxicities from this treatment approach are unpredictable, though usually reversible with management per established guidelines. Some patients suffer major morbidity and treatment-related mortality from these agents in an unpredictable manner. Cardiac and neurologic complications are rare, but can result in serious clinical consequences.

Methods

We describe the presentation, management, and outcomes of eight sequential cases of combined cardiac and neurologic toxicities resulting in severe illness and demonstrating lack of rapid response to immunosuppression.

Results

Our cohort consisted of six males and two females with an average age of 73.5 years (61–89 years). There were four patients with melanoma, and one patient each with urothelial carcinoma, renal cell carcinoma, breast cancer, and non-small cell lung cancer. Four patients received combination immunotherapy and four patients received monotherapy. The median time to presentation from treatment initiation was 27 days (11–132 days). All patients had a cardiovascular and neurologic toxicity, and most had hepatitis and myositis. The cardiac signs and symptoms were the prominent initial features of the clinical presentation. Each patient was managed by a multidisciplinary team and received a range of immunosuppressive agents. All patients died as a consequence of the immune related adverse events.

Conclusions

The evaluation of patients with cardiac adverse events from immunotherapy, should include assessment of overlapping toxicities such as myasthenia gravis and myositis. Providers should be aware of the potential for an extended duration of disability and slow improvement for certain toxicities as these expectations may factor prominently in goals of care decisions.

A multipeptide vaccine plus toll-like receptor agonists LPS or polyICLC in combination with incomplete Freund's adjuvant in melanoma patients

BACKGROUND

Cancer vaccines require adjuvants to induce effective immune responses; however, there is no consensus on optimal adjuvants. We hypothesized that toll-like receptor (TLR)3 agonist polyICLC or TLR4 agonist lipopolysaccharide (LPS), combined with CD4 T cell activation, would support strong and durable CD8⁺ T cell responses, whereas addition of an incomplete Freund's adjuvant (IFA) would reduce magnitude and persistence of immune responses.

PATIENTS AND METHODS

Participants with resected stage IIB-IV melanoma received a vaccine comprised of 12 melanoma peptides restricted by Class I MHC (12MP), plus a tetanus helper peptide (Tet). Participants were randomly assigned 2:1 to cohort 1 (LPS dose-escalation) or cohort 2 (polyICLC). Each cohort included 3 subgroups (a-c), receiving 12MP + Tet + TLR agonist without IFA (0), or with IFA in vaccine one (V1), or all six vaccines (V6). Toxicities were recorded (CTCAE v4). T cell responses were measured with IFNγ ELIspot assay ex vivo or after one in vitro stimulation (IVS).

RESULTS

Fifty-three eligible patients were enrolled, of which fifty-one were treated. Treatment-related dose-limiting toxicities (DLTs) were observed in 0/33 patients in cohort 1 and in 2/18 patients in cohort 2 (11%). CD8 T cell responses to 12MP were detected ex vivo in cohort 1 (42%) and in cohort 2 (56%) and in 18, 50, and 72% for subgroups V0, V1, and V6, respectively. T cell responses to melanoma peptides were more durable and of highest magnitude for IFA V6.

CONCLUSIONS

LPS and polyICLC are safe and effective vaccine adjuvants when combined with IFA. Contrary to the central hypothesis, IFA enhanced T cell responses to peptide vaccines when added to TLR agonists. Future studies will aim to understand mechanisms underlying the favorable effects with IFA.

TRIAL REGISTRATION

The clinical trial Mel58 was performed with IRB (#15781) and FDA approval and is registered with Clinicaltrials.gov on April 25, 2012 (NCT01585350). Patients provided written informed consent to participate. Enrollment started on June 24, 2012.

Quantitative Spatial Profiling of PD-1/PD-L1 Interaction and HLA-DR/IDO-1 Predicts Improved Outcomes of Anti-PD-1 Therapies in Metastatic Melanoma

Purpose: PD-1/L1 axis-directed therapies produce clinical responses in a subset of patients; therefore, biomarkers of response are needed. We hypothesized that quantifying key immunosuppression mechanisms within the tumor microenvironment by multiparameter algorithms would identify strong predictors of anti-PD-1 response.Experimental Design: Pretreatment tumor biopsies from 166 patients treated with anti-PD-1 across 10 academic cancer centers were fluorescently stained with multiple markers in discovery (n = 24) and validation (n = 142) cohorts. Biomarker-positive cells and their colocalization were spatially profiled in pathologist-selected tumor regions using novel Automated Quantitative Analysis algorithms. Selected biomarker signatures, PD-1/PD-L1 interaction score, and IDO-1/HLA-DR coexpression were evaluated for anti-PD-1 treatment outcomes.Results: In the discovery cohort, PD-1/PD-L1 interaction score and/or IDO-1/HLA-DR coexpression was strongly associated with anti-PD-1 response (P = 0.0005). In contrast, individual biomarkers (PD-1, PD-L1, IDO-1, HLA-DR) were not associated with response or survival. This finding was replicated in an independent validation cohort: patients with high PD-1/PD-L1 and/or IDO-1/HLA-DR were more likely to respond (P = 0.0096). These patients also experienced significantly improved progression-free survival (HR = 0.36; P = 0.0004) and overall survival (HR = 0.39; P = 0.0011). In the combined cohort, 80% of patients exhibiting higher levels of PD-1/PD-L1 interaction scores and IDO-1/HLA-DR responded to PD-1 blockers (P = 0.000004). In contrast, PD-L1 expression was not predictive of survival.Conclusions: Quantitative spatial profiling of key tumor-immune suppression pathways by novel digital pathology algorithms could help more reliably select melanoma patients for PD-1 monotherapy. Clin Cancer Res; 24(21); 5250-60. ©2018 AACR.

Quantitative spatial profiling of PD-1/PD-L1 interaction and HLA-DR/IDO1 to predict outcomes to anti-PD-1 in metastatic melanoma (MM)

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Background: Although PD-1/L1 axis directed therapies induce durable responses in some mm patients (pts), biomarkers of response remain elusive. We hypothesized that quantifying key immune suppression mechanisms within the tumor microenvironment would provide superior predictors of response to anti-PD-1 compared with single marker assessment. Methods: Pre-treatment tumor biopsies from 124 mm pts treated with anti-PD-1 at 7 academic centers were fluorescently stained with multiple immune markers in discovery (n = 24) and validation (n = 100) cohorts. Selected biomarker signatures, PD-1/PD-L1 interaction score (proportion of PD-1+ cells co-localized with PD-L1) and IDO1/HLA-DR co-expression were evaluated for anti-PD-1 treatment response and survival. Slides were imaged using Vectra; biomarker positive cells and their co-localization were objectively quantified in pathologist-selected regions using novel Automated Quantitative Analysis (AQUA) algorithms. Results: In the discovery cohort, high levels of PD-1/PD-L1 interaction score and/or IDO1/HLA-DR coexpression was strongly positively associated with response to anti-PD-1 (p = 0.0005). In contrast, other individual biomarkers (PD-1, PD-L1, CD8) were not associated with response or survival (p > 0.10). This finding was replicated in the validation cohort: pts with high PD-1/PD-L1 and/or IDO1/HLA-DR were more likely to respond to treatment (p = 0.009). These pts also experienced a three-fold increase in progression free survival (hazards ratio (HR) = 0.33; p = 0.003) and overall survival (HR = 0.34; p = 0.004). Multivariate analyses revealed that these findings were independent of BRAF mutation, stage, LDH and prior therapy. In the combined cohort (n = 124), 80% of responding pts had higher levels of PD-1/PD-L1 interaction scores and/or IDO1/HLA-DR. In contrast, PD-L1 expression alone (≥1% or ≥50%) was not predictive of PFS or OS (p > 0.1). Conclusions: This novel multiplexed method profiling key tumor-immune suppression pathways identified mm pts likely to respond to anti-PD-1 therapy. This method could help stratify patients for PD-1 monotherapy and be useful in guiding future clinical trials.

Sarcoidosis in the setting of combination ipilimumab and nivolumab immunotherapy: a case report & review of the literature

BACKGROUND

We report a case of sarcoidosis in a patient with metastatic melanoma managed with combination ipilimumab/nivolumab. Sarcoid development has been linked with single agent immunotherapy but, to our knowledge, it has not been reported with combination ipilimumab/nivolumab treatment. This case raises unique management challenges for both the melanoma and the immunotherapy-related toxicity.

CASE PRESENTATION

A 46 year old Caucasian female with M1c-metastatic melanoma was managed with ipilimumab/nivolumab combination. Patient experienced response in baseline lesions but developed new clinical and radiographic findings. Biopsy of new lesions at two different sites both demonstrated tumefactive sarcoidosis. Staining of the biopsy tissue for PD-L1 expression demonstrated strong PD-L1 staining of the histiocytes and lymphocytes within the granulomas. Monotherapy nivolumab was continued without progression of sarcoid findings or clinical deterioration.

CONCLUSIONS

Tissue biopsy for evaluation of new lesions on immunotherapy is an important step to help guide decision making, as non-melanoma lesions can mimic disease progression.

Family history of lung cancer in never smokers with non-small-cell lung cancer and its association with tumors harboring EGFR mutations

INTRODUCTION

Inherited susceptibility to lung cancer is understudied. Never smokers are an important subgroup of patients enriched for tumors harboring oncogene aberrations in the EGFR and ALK genes. We aimed to better characterize the incidence of family history of lung cancer among never smokers with NSCLC.

METHODS

Clinicopathologic data, tumor genotype, family history of cancer, and specifically family history of lung cancer from 230 consecutive never smokers was retrospectively compiled and analyzed.

RESULTS

In our cohort, the median age was 56 years, 67% were women, 75% were white, 59% had advanced NSCLC and 87% had adenocarcinoma histology. In these tumors, 98/230 (42%) had an EGFR mutation, 17/155 (11%) had KRAS mutations and 27/127 (21%) had an ALK translocation. Family history of any cancer was common (57%) and specific family history of lung cancer was present in 42/230 cases (18%). The percentage of cases with family history of lung cancer was higher in the EGFR mutated versus EGFR wild-type NSCLCs. Out of the cases with a family history of any cancer, 22/53 (41.5%) EGFR mutated, 1/5 (20%) KRAS mutated and 3/19 (15.5%) ALK translocated cohorts had a family history of lung cancer. The ratio of family history of lung cancer to family history of cancer was significantly higher in the EGFR mutated cohort when compared to the ALK translocated plus KRAS mutated cohorts (p=0.039).

CONCLUSIONS

Family history of lung cancer is common in never smokers with NSCLC, and there seems to be a particular link in families in which the proband has an EGFR mutated tumor when compared to ALK translocated or KRAS mutated tumors. Further study of families with EGFR-mutated NSCLC may yield insights into the pathogenesis of this tumor type.

Case series of treatment approaches in fit nonagenarians with stage IV non-small-cell lung cancer

An increasing number of nonagenarians are treated for non-small-cell lung cancer (NSCLC); however guidelines and case series describing the care of very elderly patients with advanced NSCLC are not available. Medical records of patients treated at Beth Israel Deaconess Medical Center between 2007 and 2009 who had NSCLC were reviewed, and those with stage IV NSCLC and age 90 or older were included in this case series. Three successive fit nonagenarians were identified out of the one hundred and one cases with stage IV NSCLC, and their clinical course was summarized. The first case depicts a conservative approach (best supportive care), while the later cases describe the use of platinum-based (carboplatin-pemetrexed) and anti-epidermal growth factor targeted therapies. This series illustrates the diversity of approaches now available and the evolving treatment paradigm as it applies to fit elderly with NSCLC, including nonagenarians. It also emphasizes the importance of considering performance status rather than biologic age when making treatment decisions.

Genotype-driven therapies for non-small cell lung cancer: focus on EGFR, KRAS and ALK gene abnormalities

Non-small cell lung cancers (NSCLCs) are heterogeneous cancers. In 2004, the identification of epidermal growth factor receptor (EGFR) somatic mutations provided the first glimpse of a clinically relevant NSCLC oncogene. Approximately 70% of NSCLCs with EGFR mutations (exon 19 deletions or the exon 21 L858R) attain responses to EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, with improved response rate (RR), progression-free survival (PFS) and in some reports overall survival (OS) when compared with EGFR wildtype (WT) cases. Three randomized trials of gefitinib versus chemotherapy (IPASS, WJTOG3405, NEJ002) in stage IV NSCLC have consistently demonstrated better RR and PFS (hazard ratios of 0.48 [IPASS], 0.49 [WJTOG3405] and 0.30 [NEJ002]) for EGFR-mutated NSCLCs treated with gefitinib. Novel irreversible EGFR TKIs (afatinib, XL647, PF00299804) show similar activity in EGFR-mutated patients. A translocation involving the anaplastic lymphoma kinase (ALK) gene with EML4, identified in 2007, is the most recent oncogene found in NSCLC. Crizotinib (PF02341066), an ALK TKI, has shown impressive activity against ALK translocated NSCLC in an expanded cohort of a phase I trial (NCT00585195). Over 80 patients have been treated and the RR is ∼60% with the 6-month PFS rate exceeding 70%. A registration phase III trial of crizotinib versus second-line chemotherapy (pemetrexed/docetaxel) is underway (PROFILE 1007, NCT00932893). KRAS, EGFR mutations and ALK translocations are mutually exclusive and few EGFR WT NSCLCs respond to EGFR TKIs. The promising results of EGFR and ALK TKIs in molecular subgroups of NSCLCs herald a new age of drug and clinical trial development for patients with NSCLC.

Second primary ipsilateral breast cancer with contralateral axillary involvement: a case report and literature review

After breast-conserving surgery for an initial breast cancer, the incidence of lymphatic drainage to sites other than the ipsilateral axilla, such as the contralateral axilla, increases significantly at the time of a second primary ipsilateral breast cancer. Given the likelihood of altered lymphatic drainage, and in the absence of distant metastatic sites, consideration should be given to treating patients with a second primary ipsilateral breast cancer and contralateral axillary lymph node involvement with curative intent. This clinical issue may become more common as the incidence of second primary ipsilateral breast cancer would be expected to increase due to widespread adoption of breast-conserving surgery, improved prognosis for patients with an initial early-stage breast cancer, and highly sensitive screening modalities such as magnetic resonance imaging.

Cryptorchidism in North American cattle: breed predisposition and clinical findings

The authors analyzed data collected over 26 years from 143 cryptorchid bulls admitted to 23 North American veterinary schools. Breed was found to be a risk factor. The medical records of 41 cryptorchid cattle were also obtained, and the physical examination findings, method of diagnosis, and surgical management were recorded. Polled Hereford and Shorthorn cattle were at significantly greater risk for cryptorchidism; however, polled cattle were not at an increased risk for cryptorchidism. Cryptorchidism was most commonly diagnosed by external palpation of the superficial inguinal rings and by palpation per rectum. Unilateral cryptorchidism appears to be more common than bilateral cryptorchidism. The incidence of cryptorchidism was 69% for the left testis and 31% for the right testis. Sixty-six percent of the retained testes were located in the inguinal canal. Cryptorchidectomy was performed through an inguinal, paramedian or flank approach in 26 bulls. Cryptorchidism appears to be rare in bovine bulls admitted to North American veterinary schools, with 1.7 cases per 1,000 bull admissions. We suggest that cryptorchidism be considered an inherited trait in the Shorthorn and Polled Hereford breeds.

HIV-associated bladder cancer: a case series evaluating difficulties in diagnosis and management

BACKGROUND

Chronic human immunodeficiency virus (HIV) infection is associated with an increased incidence of Non-Acquired Immunodeficiency Syndrome (non-AIDS) defining cancers. To date, only a limited number of cases of bladder cancer have been linked with HIV infection. We sought to describe the clinical characteristics of HIV-associated bladder cancer.

METHODS

A retrospective study was performed involving HIV-positive patients with bladder cancer, combining cases from multiple institutions with published case reports. Data regarding patient demographics, HIV status, clinical presentation, pathology, cancer treatment, and outcome were analyzed using descriptive statistics.

RESULTS

Eleven patients were identified with a median age of 55 years (range, 33-67). The median CD4+ count at cancer diagnosis was 280 cells/mm3 (range, 106-572 cells/mm3). Six patients (55%) had a known risk factor for bladder cancer, and nine (82%) presented with hematuria. Ten patients had transitional cell carcinoma, and most had superficial disease at presentation. Treatment included mainly transurethral resection of bladder tumor followed by a combination of local and systemic therapies. One patient received intravesical bacillus Calmette-Guèrin (BCG) without complication. Several patients (55%) were alive following therapy, although many (64%) suffered from local relapse and metastatic disease.

CONCLUSION

Bladder cancer is part of the growing list of cancers that may be encountered in patients living longer with chronic HIV-infection. Our patients presented at a younger age and with only mild immunosuppression, however, they experienced an expected course for their bladder cancer. Hematuria in an HIV-infected patient warrants a complete evaluation.

Human immunodeficiency virus--associated renal cell carcinoma: a transatlantic case series

OBJECTIVE

The spectrum of diseases associated with human immunodeficiency virus (HIV) infection has changed dramatically following the introduction of highly active antiretroviral therapy (HAART). Non-AIDS-defining cancers, including renal cell carcinoma (RCC), are being recognized increasingly in this population. Our aim was to describe the risk factors, clinical findings, pathology, and response to therapy of RCC in patients infected with HIV.

PATIENTS AND METHODS

We identified 9 men with HIV infection who developed RCC. Data regarding their HIV status, RCC risk factors, clinical presentation, and pathology were collected. A detailed retrospective chart review focusing on the course of their malignancy, response to therapy, and outcome was performed.

RESULTS

Renal cell carcinoma was diagnosed in patients with a median age of 48 years, and most had a history of tobacco use. No association between HIV-related immunosuppression (mean CD4 count, 301 cells/mm3) and the development, clinical presentation, pathology, or behavior of RCC was identified. Long-term survival correlated with early nephrectomy, and the use of interleukin-2 therapy for advanced RCC was not additive. A total of 5 patients died, 1 from a pulmonary embolism and 4 from disseminated RCC.

CONCLUSION

Renal cell carcinoma should be included in the expanding array of non-AIDS-defining malignancies that develop during the course of HIV infection. Acknowledging the inherent limitations of our small study, these data show that the clinical presentation and behavior of RCC in patients with HIV appear similar to that of the HIV-negative population and that chronic immunosuppression plays a lesser role than age and exposure to risk factors in this setting.

Serious infection from Staphylococcus aureus in 2 HIV-infected patients receiving fusion inhibitor therapy

Fusion inhibitors are novel antiretroviral agents, administered as subcutaneous injections, approved for use in treatment-experienced HIV-infected patients. HIV-infected patients are at increased risk for Staphylococcus aureus colonization, specifically with methicillin-resistant S aureus (MRSA), and subsequent systemic infection. We present the cases of 2 patients without a history of MRSA infection in whom a series of severe S aureus infections developed after fusion inhibitor therapy.

Fibrosarcoma over the tarsal groove of a 14-month-old Quarter horse

A 14-month-old male Quarter horse was presented for evaluation of a grade 3 out of 5 (grade 0 = sound; grade 5 = non-weight bearing) right rear lameness. A firm, 8 x 16 cm mass was palpable at the caudal medial aspect of the distal tibia and proximal tarsal region of the right hind limb. A percutaneous needle aspirate contained mesenchymal cells that were moderate to large in size with single, oblong nuclei. Differential diagnoses included fibrous hyperplasia, fibroma, or well-differentiated fibrosarcoma. Excisional biopsy for both definitive diagnosis and treatment was offered and selected by the owner. A fibrosarcoma was confirmed by histological examination of the mass. One and a half years after resection signs of lameness or evidence of regrowth of the mass were not evident.

The effect of intra-articular methylprednisolone acetate and exercise on equine carpal subchondral and cancellous bone microhardness

Dorsal carpal osteochondral injury is a major cause of lameness in horses undergoing high intensity training. Intra-articular corticosteroid treatment is used commonly to manage exercise-associated articular pain, but its use remains highly controversial in the equine athlete. This project, therefore, aimed to compare the mechanical properties of intra-articular MPA and diluent-treated middle carpal subchondral and cancellous bone in horses undergoing a short-term treadmill exercise programme. It was hypothesised that subchondral and cancellous bone mechanical properties are influenced by intra-articular administration of methylprednisolone acetate (MPA). Eight 2-year-old female horses had MPA or diluent administered into contralateral middle carpal joints at 14 day intervals, for a total of 4 treatments per horse. Horses underwent a standard treadmill exercise protocol until euthanasia (Day 70). Standard sites were located on the dorsal aspect of third, radial and intermediate carpal bones. Osteochondral samples from each test site were divided into subchondral bone and cancellous bone portions. These were dried, resin-embedded and gold-coated. Microhardness measurements were obtained at each test site. No significant effect of intra-articular treatment was detected. At each site, cancellous bone trabecular struts had an 18-19% higher microhardness value than the overlying subchondral bone. These findings indicate that intra-articular administration of MPA at this dose has no effect on subchondral or cancellous bone adaptation to short-term exercise and, therefore, on the propensity of carpal bones to injury. Further investigation into the calcified cartilage layer, effect of different corticosteroid preparations and diffusion of medication are required.

Severe complication after administration of formalin for treatment of progressive ethmoidal hematoma in a horse

Formalin was injected into an ethmoidal hematoma in an 18-year-old Arabian gelding. Abnormal neurologic signs were observed within minutes of the injection. The horse did not respond favorably to medical treatment of the neurologic signs and was euthanatized. Postmortem examination revealed erosion and necrosis of the ventral cribriform plate, which appeared to have allowed the injected formalin to reach the rostral portion of the frontal lobe of the brain. Endoscopy and radiography had been performed prior to euthanasia, but neither delineated the cribriform lesion. Before treating large progressive ethmoidal hematomas with formalin, it may be beneficial to perform computed tomography to assess the extent of damage caused by the lesion.

Esophagomyotomy and esophagopexy to create a diverticulum for treatment of chronic esophageal stricture in 2 horses

We report use of esophagomyotomy and esophagopexy to create a diverticulum for relief of chronic type I esophageal stricture in 2 horses. After esophagomyotomy, the mucosa was dissected free from the muscularis for approximately 180 degrees around the myotomy. Then, the tunica muscularis of esophagus was sutured to the sternocephalicus muscle ventrally and the periesophageal tissues dorsally to create a diverticulum without disruption of the esophageal mucosa. Clinical signs of esophageal stricture were relieved, and the horses were fed normal diets without further esophageal obstruction.

Determination of synovial fluid and serum concentrations, and morphologic effects of intraarticular ceftiofur sodium in horses

OBJECTIVES

To determine the serum and synovial fluid concentrations of ceftiofur sodium after intraarticular (IA) and intravenous (IV) administration and to evaluate the morphologic changes after intraarticular ceftiofur sodium administration.

STUDY DESIGN

Strip plot design for the ceftiofur sodium serum and synovial fluid concentrations and a split plot design for the cytologic and histopathologic evaluation.

ANIMALS

Six healthy adult horses without lameness.

METHODS

Stage 1: Ceftiofur sodium (2.2 mg/kg) was administered IV. Stage 2: 150 mg (3 mL) of ceftiofur sodium (pHavg 6.57) was administered IA into 1 antebrachiocarpal joint. The ceftiofur sodium was reconstituted with sterile sodium chloride solution (pH 6.35). The contralateral joint was injected with 3 mL of 0.9% sterile sodium chloride solution (pH 6.35). Serum and synovial fluid samples were obtained from each horse during each stage. For a given stage, each type of sample (serum or synovial fluid) was collected once before injection and 12 times after injection over a 24-hour period. All horses were killed at 24 hours, and microscopic evaluation of the cartilage and synovium was performed. Serum and synovial fluid concentrations of ceftiofur sodium were measured by using a microbiologic assay, and pharmacokinetic variables were calculated. Synovial fluid was collected from the active joints treated during stage 2 at preinjection and postinjection hours (PIH) 0 (taken immediately after injection of either the ceftiofur sodium or sodium chloride), 12, and 24, and evaluated for differential cellular counts, pH, total protein concentration, and mucin precipitate quality.

RESULTS

Concentrations of ceftiofur in synovial fluid after IA administration were significantly higher (P = .0001) than synovial fluid concentrations obtained after IV administration. Mean peak synovial fluid concentrations of ceftiofur after IA and IV administration were 5825.08 microg/mL at PIH .25 and 7.31 microg/mL at PIH 4, respectively. Mean synovial fluid ceftiofur concentrations at PIH 24 after IA and IV administration were 4.94 microg/mL and .12 microg/mL, respectively. Cytologic characteristics of synovial fluid after IA administration did not differ from cytologic characteristics after IA saline solution administration. White blood cell counts after IA ceftiofur administration were < or =3,400 cells/ML. The mean synovial pH of ceftiofur treated and control joints was 7.32 (range, 7.08-7.5) and 7.37 (range, 7.31-7.42), respectively. Grossly, there were minimal changes in synovium or cartilage, and no microscopic differences were detected (P = .5147) between ceftiofur-treated joints and saline-treated joints. The synovial half-life of ceftiofur sodium after IA administration joint was 5.1 hours.

CONCLUSIONS

Synovial concentrations after intraarticular administration of 150 mg of ceftiofur sodium remained elevated above minimal inhibitory concentration (MIC90) over 24 hours. After 2.2 mg/kg IV, the synovial fluid ceftiofur concentration remained above MIC no longer than 8 hours.

CLINICAL RELEVANCE

Ceftiofur sodium may be an acceptable broad spectrum antimicrobial to administer IA in septic arthritic equine joints.

Effects of external thermal manipulation on laminar temperature and perfusion scintigraphy of the equine digit

AIMS

To assess the effects of external thermal manipulation on the soft-tissue and vascular perfusion of the equine digit using nuclear scintigraphy and documented tissue temperatures.

METHODS

Six horses were used in a randomised crossover design. Each horse was treated with external heat (47 degrees C) or external cold (4 degrees C) applied to a digit for 30 minutes. The opposite front foot was untreated and used for control measurements. Nuclear scintigraphy was performed before, during, and after therapy to assess vascular and soft-tissue perfusion to the digit in response to therapy. Dorsal hoof wall laminar-tissue temperatures were recorded before, during, and after therapy using a thermistor.

RESULTS

Treatment with topical cold therapy significantly decreased soft-tissue perfusion of the digit to 80.5% of the pre-cooled values. Conversely, the application of external heat significantly increased soft-tissue perfusion of the digit 25.1% above the pre-heated values. Vascular perfusion showed similar, but not statistically significant trends. External cold application to the digit caused a significant mean decrease in laminar-tissue temperatures of 11.6 degrees C during therapy, while external heat application to the digit caused a significant mean increase in laminar-tissue temperatures of 3.9 degrees C.

CONCLUSION

The external application of heat and cold to the normal equine foot could effectively alter soft-tissue perfusion and laminar-tissue temperatures within 30 minutes of treatment. The application of hot water and ice water to the digit was a safe, well-tolerated, and economical therapy.

CLINICAL RELEVANCE

Cooling the foot could decrease enzymatic reactions associated with laminitis, and warming could increase local perfusion when desired.

Arthrodesis of the proximal interphalangeal joint affected with septic arthritis in 8 horses

Arthrodesis was performed to treat septic arthritis of the proximal interphalangeal joint of 8 horses. Records of the horses were reviewed to determine outcome and possible factors that influenced success or failure. All horses were female. Seven horses had 1 joint treated and 1 horse was treated for bilateral pelvic limb involvement. The duration of sepsis before surgery ranged from 1 to 66 days. Bone lysis and production was radiographically apparent in 7 horses before surgery. Six horses had multiple bacterial organisms cultured from bone or synovial tissues; 2 horses had single isolates identified. After aggressive curettage, arthrodesis was accomplished with 3 parallel screws in 1 horse, 2 divergent narrow dynamic compression plates in 3 horses, and a single broad dynamic compression plate in 4 horses. Casts were applied to all horses for 1 to 6 weeks. Four horses survived to successful brood mare status. Four horses were euthanized during hospitalization because of continued discomfort or complications of sepsis. Arthrodesis of the proximal interphalangeal joint affected with septic arthritis appears to be an acceptable alternative to euthanasia for some horses.

Effect of furosemide on pulmonary blood flow distribution in resting and exercising horses

We determined the spatial distribution of pulmonary blood flow (PBF) with 15-micron fluorescent-labeled microspheres during rest and exercise in five Thoroughbred horses before and 4 h after furosemide administration (0.5 mg/kg iv). The primary finding of this study was that PBF redistribution occurred from rest to exercise, both with and without furosemide. However, there was less blood flow to the dorsal portion of the lung during exercise postfurosemide compared with prefurosemide. Furosemide did alter the resting perfusion distribution by increasing the flow to the ventral regions of the lung; however, that increase in flow was abated with exercise. Other findings included 1) unchanged gas exchange and cardiac output during rest and exercise after vs. before furosemide, 2) a decrease in pulmonary arterial pressure after furosemide, 3) an increase in the slope of the relationship of PBF vs. vertical height up the lung during exercise, both with and without furosemide, and 4) a decrease in blood flow to the dorsal region of the lung at rest after furosemide. Pulmonary perfusion variability within the lung may be a function of the anatomy of the pulmonary vessels that results in a predominantly fixed spatial pattern of flow distribution.

A retrospective analysis of left dorsal displacement of the large colon treated with phenylephrine hydrochloride and exercise in 12 horses (1996–98)

AIM

To review the outcome of cases of left dorsal displacement of the large colon (LDDLC) treated with phenylephrine HCl and mild exercise.

METHODS

Physical parameters, laboratory data, ultrasonographic findings and outcome were analysed in a retrospective study of 12 horses with a confirmed diagnosis of LDDLC which were treated with phenylephrine HCl and mild exercise.

RESULTS

Administration of phenylephrine HCl and mild exercise resulted in the resolution of LDDLC in 11 of 12 treated horses. One horse failed to resolve the entrapment and required surgical correction.

CONCLUSION

Administration of phenylephrine HCl appears to be an effective treatment for horses with confirmed diagnosis of LDDLC presented with mild to moderate colonic distention.

Evaluation of mild lameness in horses trotting on a treadmill by clinicians and interns or residents and correlation of their assessments with kinematic gait analysis

OBJECTIVE

To estimate sensitivity and accuracy of subjective evaluation of mild lameness in horses during treadmill locomotion and to correlate subjective evaluation with kinematic analysis.

ANIMALS

19 lame and 5 clinically normal horses.

PROCEDURE

Lameness was evaluated by subjective score and kinematic analysis before and after palmar digital nerve block (PDNB). Evaluations were made by 6 clinicians and 7 interns or residents. Within- and between-observer agreement analyses (kappa values) were calculated and compared, using a Student's t-test. Pearson's product-moment correlation coefficients were calculated between clinician's change in score and the change in kinematic variables after PDNB.

RESULTS

Within-observer agreement was within the range expected for conditions of moderate diagnostic difficulty. Within-observer agreement was higher for clinicians than for interns or residents. Between-observer agreement was acceptable for scores within 1 value of each other. Between-observer agreement of change in lameness score after PDNB was poor. When kinematic variables were ranked with each clinician's subjective change in score, only 2 were among the top 3 for the majority of clinicians. Asymmetry of vertical head movement between contralateral forelimb stance phases and the point of maximum hoof height during swing decreased as lameness subjectively improved.

CONCLUSION

Mild lameness may be difficult to evaluate during treadmill locomotion. Although clinicians were more repeatable in their subjective evaluation of lameness than interns or residents, they were not more reliable at detecting the true state of lameness.

CLINICAL RELEVANCE

Lack of agreement between clinician scoring of mild lameness emphasizes the need to use more objective measures for quantifying lameness.

Dental surgery in horses

Dental surgery is most often directed at removal of diseased or injured teeth by the least invasive method possible. Some procedures available can preserve traumatized or infected teeth. Complications of dental surgery are well documented and often encountered by veterinary surgeons. Principles of debridement, curettage, lavage and ventral drainage combined with appropriate medicinal management can reduce complications and lead to successful outcome after dental surgery.

Congenital dental disease of horses

Equine congenital dental deformities are not limited merely to those presented here; however, the examples discussed offer the reader an appreciation for the range of severity and complexity that may be found in affected horses. The veterinarian is obligated to provide the best possible care for the patient and to relieve animal suffering. The lack of definitive evidence for heritability of many of these defects can place the veterinarian in an untenable position, particularly when presented with literature that proclaims or suggests without evidence that a particular condition is inherited. In such cases, the veterinarian is encouraged to counsel owners, citing substantiated medical information, and to recommend that owners make the decision to eliminate the affected animals' ability to reproduce.

Quantification of exercise-induced pulmonary haemorrhage with bronchoalveolar lavage

Exercise-induced pulmonary haemorrhage (EIPH) causes serious economic losses in the horse racing industry. Endoscopic examination indicates that 40-90% of horses exhibit EIPH following sprint exercise, but the limitations of the endoscope prevent diagnosis in many horses. Bronchoalveolar lavage (BAL) was utilised to detect red blood cells (RBCs) in the terminal airways in 6 horses. Two lavages were performed at weekly intervals prior to exercise, one within 90 min after exercise, and 5 at weekly intervals after exercise. The horses were exercised strenuously at 12.5-14.6 m/s on a treadmill (3 degree incline). Heart rates ranged from 192-207 beats/min, and mean pulmonary arterial pressures (mPAP) ranged from 80-102 mmHg. Neither epistaxis nor endoscopic evidence of EIPH was seen in any of the 6 horses following exercise. However, the number of RBCs in the lavage fluid increased significantly over control values immediately after exercise in all horses but returned to control values by one week after exercise. Haemosiderophages in the BAL fluid did not increase until one week after exercise and remained elevated for 3 weeks after exercise. Twenty per cent of the total population of alveolar macrophages contained haemosiderin. A positive relationship occurred between the number of RBCs in the lavage fluid and mPAP; the amount of haemorrhage increased as the mPAP exceeded 80 to 90 mmHg. The results with BAL used as the diagnostic tool, suggest that all strenuously exercised horses may exhibit EIPH; the amount of haemorrhage appears to be associated with the magnitude of the high pulmonary arterial pressure.

The effects of intra-articular methylprednisolone and exercise on the mechanical properties of articular cartilage in the horse

INTRODUCTION

Intra-articular corticosteroids are widely used as anti-inflammatory agents for symptomatic management of arthritis, but their administration with concurrent exercise remains controversial. Biochemical and morphologic analysis of treated cartilage has revealed conflicting results, but previous biomechanical assessment has not been undertaken.

OBJECTIVE

To compare the biomechanical properties of intra-articular methylprednisolone acetate (MPA) and diluent treated cartilage in treadmill exercised horses.

METHODS

Eight 2-year-old female horses had MPA or diluent administered into contralateral middle carpal joints at 14 day intervals for a total of four treatments per horse. Horses underwent a standard treadmill exercise protocol until euthanasia (day 70). Standard sites were tested on the third, radial and intermediate carpal bones using an automated indentation apparatus to obtain the creep and recovery behavior of the articular cartilage. Using previously validated biphasic creep indentation methodology, aggregate modulus, Poisson's ratio, permeability, shear modulus, thickness, creep and recovery equilibrium times and percent recovery were obtained at each site. Results were analyzed using ANOVA and multiple comparisons of the means (P < 0.05).

RESULTS

Cartilage intrinsic material properties and thickness demonstrated significant differences between MPA and diluent treated joints. Diluent treated cartilage had a 97% increase in compressive stiffness modulus (P = 0.0001), was 121% more permeable (P = 0.0001), had 88% increase in shear modulus (P = 0.0001), and was 24% thicker (P = 0.0001) than MPA treated articular cartilage.

CONCLUSIONS

The findings indicate that repetitive intra-articular administration of MPA to exercising horses alters the mechanical integrity of articular cartilage, which could lead to early cartilage degeneration.

Development of interactive patient-based multimedia computer programs in veterinary orthopedic radiology

Three computerized multimedia programs on large and small animal veterinary orthopedic radiology were developed and implemented for the radiology curriculum as an alternative to traditional film-based laboratory learning. Programs utilized "hot words" (colored text words that displayed an overlaid image label that highlighted lesions) and interactive quizzes which responded appropriately to selected answers. "Hot words" helped students develop confidence in accurate lesion detection and the interactive quizzes transformed learning from a passive to an active process. Multiple examples were provided for reinforcement and concepts were incorporated from other clinical disciplines for curriculum integration. Programs were written using a presentation software program, Toolbook for DOS based platform, and contained radiographic images made by laser-scanning digitization. Multiple students could simultaneously access the programs through a network server. These pilot programs were implemented successfully and computerized multimedia presentation proved to be well suited to teaching radiology. Development of the programs required attention to a number of hardware, software, time and cost factors.

Biomechanical comparison of the Herbert and AO cortical bone screws for compression of an equine third carpal bone dorsal plane slab osteotomy

OBJECTIVE

To assess feasibility of insertion of 4.5-mm Herbert cannulated bone screws (HS) using fluoroscopic guidance and compare the mechanical shear strength of these HS and 4.5-mm AO cortical bone screws (AO) for fixation of dorsal plane slab osteotomies in equine cadaver third carpal bones (C3).

ANIMALS OR SAMPLE POPULATION

Eight equine cadavers.

METHODS

Bone mineral composition and density of contralateral C3 were confirmed to be equivalent using dual-energy x-ray absorptiometry. A standard 10-mm C3 slab osteotomy was reduced using HS or AO instrumentation under fluoroscopic guidance. Specimens were loaded in shear until failure, using a materials testing apparatus.

RESULTS

HS and AO instrumentation allowed accurate reconstruction of the osteotomy, but there was difficulty encountered seating the HS proximal self-tapping threads. There was no significant difference in maximal load to failure, stiffness, or mode of failure of constructs created with the HS and AO screws.

CONCLUSIONS

Use of 4.5-mm HS for repair of C3 radial facet, dorsal plane slab fractures may result in a mechanically comparable fixation to a repair using a 4.5-mm AO. Equine dorsal C3 may be too dense, however, to allow placement of the proximal self tapping threads of the HS without potentially excessive application of torque to the screw itself.

CLINICAL RELEVANCE

Dorsal plane, radial facet slab fractures of the equine C3 are a significant clinical problem. Accurate reconstruction and stabilization are necessary for return to athletic function.

Effects of carbon dioxide insufflation combined with changes in body position on blood gas and acid-base status in anesthetized llamas (Llama glama)

OBJECTIVE

To study the combined effects of intra-abdominal CO2 insufflation with changes in body position during laparoscopy in xylazine-ketamine-halothane anesthetized llamas.

STUDY DESIGN

Prospective, controlled study.

ANIMALS

Nine castrated, male llamas weighing 114 +/- 23 kg, 3 to 13 years old.

METHODS

Three llamas (preliminary study [PS] group) were used to study the effect of right, lateral, dorsal, and left lateral recumbency on gas exchange and acid-base status. The other six (experimental study [ES] group) were used to study the combined effects of changes in body position and CO2 insufflation to an intraabdominal pressure of 10 to 12 mm Hg. Heart rate, respiratory rate, and indirect arterial blood pressures (systolic [SAP], mean [MAP], and diastolic [DAP]) were recorded every 5 minutes during anesthesia. Arterial blood gases (PaO2 and PaCO2) and acid-base status (pHa and HCO3-) were measured immediately after induction of anesthesia and before each change of position.

RESULTS

In the PS group, significant decreases in SAP, MAP and PaCO2 and increases in PaO2 and pHa were observed when the llamas were turned from right lateral to dorsal recumbency. Values for HCO3- were lower than the postinduction values, but they remained unaffected by the changes in position. In the ES group, values for MAP were significantly lower when the llamas were placed in dorsal and left lateral recumbency than those observed during right lateral recumbency. Arterial O2 tension during right lateral recumbency was lower but returned to preinsufflation values when the llamas were placed in the dorsal position. All llamas recovered uneventfully within 30 minutes after termination of anesthesia.

CONCLUSIONS

Insufflation of CO2 and changing body position induce minor and transient changes in cardiovascular and respiratory function.

CLINICAL RELEVANCE

Laparoscopy with mild intra-abdominal CO2 insufflation (10 to 12 mm Hg) can be used safely in spontaneously breathing llamas anesthetized with xylazine, ketamine, and halothane.

Diagnostic approach to exercise intolerance in racehorses

The diagnostic approach to the exercise intolerant racehorse depends on sound, fundamental steps to allow complete examination of the entire horse in a logical, time-efficient fashion. Availability of referral diagnostic modalities should not overshadow the need for collecting a clinical history or performing a complete physical examination. The diagnostic approach to exercise intolerance can be divided into a few basic steps. The first step, conducted without the horse, is a thorough discussion about the horse with the trainer and/or owner. Many clinical histories are complex and therefore following a predetermined pattern is helpful. Racing ability, general health history, historic problems with the major body systems including the musculoskeletal, respiratory, cardiovascular, and neurologic systems should be reviewed. The next step of the examination is conducted in the stall. A complete physical examination is required. The practitioner should pay close attention to the body systems that most frequently harbor causes of exercise intolerance. Before evaluating the horse for lameness, endoscopy of the upper airway should be performed. The final step is conducted outside the stall: completion of the lameness and neurologic examination or an exercise trial followed by further diagnostic tests such as a serum chemistry profile, bronchoalveolar lavage, or imaging studies. Decision for referral is best made after the physical examination is completed and capability for further diagnostics is exhausted.

Exercise intolerance in endurance horses

Endurance competition requires synchronism and development of metabolic and musculoskeletal systems. An understanding of the existence of performance-limiting factors may permit the detection of exercise intolerance that could lead to performance failure, fatigue, and exhaustion. New concepts for assessment of fitness have increased the understanding of individual capacities and deficiencies and the interaction of the different systems involved in exercise.

Skeletal origins of exercise intolerance in horses

Skeletal origins of exercise intolerance and performance failure can reside in multiple tissues. Diagnosis of injury that results in an ability to continue to exercise, yet inefficiently do so, requires familiarity with evaluation of subtle lameness and often with the specific demands of the different equine sports. Imaging is usually vital to diagnosis development and understanding of lesion influences on locomotion. Therapy is lesion dependent. Return to competitive exercise and performance is dictated by an understanding of skeletal tissue response to injury, rational progressive treatment, and a controlled reintroduction of exercise demands.

Pulmonary blood flow distribution in standing horses is not dominated by gravity

Recent studies using microspheres in dogs, pigs and goats have demonstrated considerable heterogeneity of pulmonary perfusion within isogravitational planes. These studies demonstrate a minimal role of gravity in determining pulmonary blood flow distribution. To test whether a gravitational gradient would be more apparent in an animal with large vertical lung height, we measured perfusion heterogeneity in horses (vertical lung height = approximately 55 cm). Four unanesthetized Thoroughbred geldings (422-500 kg) were studied awake in the standing position with fluorescent microspheres injected into a central vein. Between 1,621 and 2,503 pieces (1.3 cm3 in volume) were obtained from the lungs of each horse with spatial coordinates, and blood flow was determined for each piece. The coefficient of variation of blood flow throughout the lungs ranged between 22 and 57% among the horses. Considerable heterogeneity was seen in each isogravitational plane. The relationship between blood flow and vertical height up the lung was characterized by the slope and correlation coefficient of a least squares regression analysis. The slopes within each horse ranged from -0.052 to +0.021 relative flow units/cm height up the lung, and the correlation coefficients varied from 0.12 to 0.75. A positive slope, indicating that flow increased with vertical distance up the lung (opposite to gravity), was observed in three of the four horses. In addition, blood flow was uniformly low in three of the four horses in the most cranial portions of the lungs. We conclude that in lungs of resting unanesthetized horses, animals with a large lung height, there is no consistent vertical gradient to pulmonary blood flow and there is a considerable degree of perfusion heterogeneity, indicating that gravity alone does not play the major role in determining blood flow distribution.