Using stable isotopes in hummingbird breath to estimate reliance on supplemental feeders

Understanding the ecological consequences of supplemental feeding to both hummingbirds and the plants they pollinate is complicated by logistical challenges associated with assessing relative dietary resource use with commonly applied observational methods. Here, we describe the results of research conducted to assess the relative use of feeder and flower nectar by Broad-tailed (Selasphorus platycercus) and Rufous hummingbirds (Selasphorus rufus) using two distinct methodological variations to measure the δ¹³C values of exhaled CO₂. Because of the relatively quick time in which both species switch from exogenous to endogenous resources to fuel metabolism, our experiment allowed us to assess resource use at two timescales. Our results suggest variability in the relative contributions of the two dietary sources within and among species and timescales, with most birds employing a mixture of feeder and flower sugars as fuel sources. This diversity in relative resource use may mitigate potential negative effects of supplemental feeding on hummingbirds and their plant symbionts.

POS1234 DMARD DISRUPTION, INCREASED DISEASE ACTIVITY, AND PROLONGED SYMPTOM DURATION AFTER ACUTE COVID-19 AMONG PATIENTS WITH RHEUMATIC DISEASE: A PROSPECTIVE STUDY

Background

Systemic autoimmune rheumatic disease (SARD) patients may be at risk for disease flare and prolonged symptom duration after COVID-19, perhaps related to DMARD disruption and immune activation.

Objectives

To describe DMARD disruption and identify differences in SARD activity among patients with and without prolonged COVID-19 symptom duration.

Methods

We identified all SARD patients with confirmed COVID-19 at the Mass General Brigham healthcare system in Boston, USA; prospective recruitment is ongoing. Surveys were used to collect demographics, clinical characteristics, DMARD disruption, COVID-19 course, and SARD disease activity before and after COVID-19. The survey included validated instruments measuring disease activity, pain, fatigue, functional status, and respiratory quality of life. Prolonged symptom duration was defined as COVID-19 symptoms lasting ≥28 days. We compared differences in patient-reported measures between those with and without prolonged symptoms.

Results

We analyzed survey responses from 174 COVID-19 survivors with SARDs (mean age 52±16 years, 81% female, 80% White). The most common SARDs were RA (40%) and SLE (14%). Fifty-one percent of the 127 respondents on any DMARD reported a disruption to their regimen at COVID-19 onset (Figure 1). Among individual DMARDs, 56-77% were reported to have any change, except for hydroxychloroquine (23%) and rituximab (46%). SARD flare after COVID-19 was reported by 41% of respondents (Table 1). Patient global assessment of SARD activity was worse after COVID-19 (mean 7.6±2.3 before vs. 6.6±2.9 after COVID-19, p<0.001). Prolonged symptom duration was reported by 45% of participants. Those with prolonged symptoms had a higher initial COVID-19 symptom count (median 7 vs. 4, p<0.001) and were more likely to be hospitalized for COVID-19 (28% vs. 17%, p=0.001). Respondents experiencing prolonged symptom duration had higher disease activity on RAPID3 (p=0.007) as well as more pain (p<0.001) and fatigue (p=0.03) compared to those without prolonged symptoms.

Table 1.

Acute COVID-19 course, SARD flare/activity, and patient-reported outcomes among COVID-19 survivors with SARDs.

All COVID-19 survivors with SARDs (n=174)Prolonged symptom duration ≥28 days (n=78)No prolonged symptom duration/(n=96)p-value (prolonged vs. not)Acute COVID-19 courseCOVID-19 symptom duration, days, median [IQR]14 [9, 29]46 [30, 65]11 [7, 14]<0.0001Initial symptom count, median [IQR]6 [3, 8]7 [6, 9]4 [2, 7]<0.001Hospitalized, n (%)38 (22)22 (28)16 (17)0.001SARD flare/activitySelf-reported SARD flare after COVID-19, n (%)71 (41)38 (49)33 (34)0.15Disease activity by RAPID3, median [IQR]9 [4, 14]11.2 [6, 16]7 [3, 13]0.0067RAPID3 categorical score, n (%)0.13Remission (0)11 (7)4 (5)7 (7)Near remission (0.3-1.0)23 (14)5 (7)18 (19)Low severity (1.3-2.0)26 (15)10 (14)16 (17)Moderate severity (2.3-4.0)55 (33)27 (36)28 (29)High severity (4.3-10.0)54 (32)28 (38)26 (27)Patient-reported outcomesPain by SF-MPQ, median [IQR]2 [1, 2]2 [1, 2]1 [0, 2]0.0008Fatigue by FSI, median [IQR]53 [27, 84]66 [31, 91.5]43 [26, 76]0.031mHAQ, median [IQR]0.125 [0, 0.38]0.25 [0, 0.75]0.125 [0, 0.38]0.11Respiratory quality of life by SGRQ, global [IQR]15 [4, 29]16 [4, 36]10 [4, 26]0.49

RAPID3, Routine Assessment of Patient Index Data 3; SF-MPQ, Short-form McGill Pain Questionnaire; FSI, Fatigue Symptom Inventory; mHAQ, modified Health Assessment Questionnaire; SGRQ, Saint George’s Respiratory Questionnaire.

Figure 1.

Frequency of baseline DMARD use and proportion with any disruption at COVID-19 onset.

Conclusion

DMARD disruption, SARD flare, and prolonged symptoms were common in this prospective study of COVID-19 survivors with SARDs. Those with prolonged COVID-19 symptom duration, defined as ≥28 days, had higher SARD activity, more pain, and more fatigue compared to those without prolonged symptoms. These findings suggest that post-acute sequelae of COVID-19 may have a large impact on underlying SARD activity and quality of life.

Disclosure of Interests

Michael Di Iorio: None declared, Claire Cook: None declared, Kathleen Vanni: None declared, Naomi Patel Consultant of: Receives consulting fees from FVC Health unrelated to this work., Kristin D’Silva: None declared, Xiaoqing Fu: None declared, Jiaqi Wang: None declared, Lauren Prisco: None declared, Emily Kowalski: None declared, Alessandra Zaccardelli: None declared, Lily Martin: None declared, Grace Qian: None declared, Tiffany Hsu: None declared, Zachary Wallace Consultant of: Receives consulting fees from Viela Bio, Zenas BioPharma, and MedPace unrelated to this work., Grant/research support from: Receives research support from Bristol-Myers Squibb and Principia/Sanofi., Jeffrey Sparks Consultant of: Receives consultant fees from AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Gilead, Inova Diagnostics, Janssen, Optum, and Pfizer unrelated to this work., Grant/research support from: Receives research support from Bristol Myers Squibb.

OP0251 IMPACT OF INTERSTITIAL LUNG DISEASE ON SEVERE COVID-19 OUTCOMES FOR PATIENTS WITH RHEUMATOID ARTHRITIS: A MULTICENTER STUDY

Background

RA has been associated with poor COVID-19 outcomes, but few studies have investigated outcomes in RA features such as interstitial lung disease.

Objectives

To assess COVID-19 outcomes in patients with RA overall, and those with and without ILD, compared to general population comparators.

Methods

A multicenter, retrospective cohort study was conducted at Mayo Clinic (19 hospitals and affiliated outpatient centers in 4 states) and Mass General Brigham (14 hospitals and affiliated outpatient centers in New England). Consecutive patients with RA meeting ACR/EULAR criteria and a positive COVID-19 test from March 1, 2020 through June 6, 2021 were matched 1:5 on age, sex, race, and COVID-19 test date with general population comparators without RA. RA features assessed included: RA-ILD per Bongartz criteria [1], duration, rheumatoid factor (RF), cyclic citrullinated peptide antibody (CCP), bone erosions, and treatments. The primary outcome was a composite of hospitalization or death following COVID-19 diagnosis. We used multivariable Cox regression to investigate the association of RA, and features such as ILD, with COVID-19 outcomes compared to matched comparators.

Results

We analyzed 582 patients with RA and 2892 comparators without RA, all with COVID-19. Mean age was 62 years, 51% were female, and 79% were White. Mean RA duration was 11 years, 67% were seropositive (52% RF+ and 54% CCP+), 27% had bone erosions, 28% were on steroids, and 79% were on DMARDs. 50/582 (9%) patients with RA had ILD.

The COVID-19 hospitalization or death rate for RA patients was higher than comparators (3.0 per 1,000 days [95% CI 2.5-3.6] vs. 1.9 per 1,000 days [95% CI 1.7-2.1], respectively). Overall, RA patients had a 53% higher risk of hospitalization or death than comparators after adjustment (95% CI 1.20-1.94).

Among those with RA-ILD, the hospitalization or death rate was significantly higher than comparators (10.9 [95% CI 6.7-15.2] vs. 2.5 per 1,000 days [1.8-3.2], respectively). RA-ILD was associated with nearly 3-fold higher risk for hospitalization or death than comparators (multivariable HR 2.84 [95% CI 1.64-4.91], Table 1). There was a significant interaction between RA/comparator status and presence/absence of ILD for risk of severe COVID-19 (p<0.001, Figure 1). The elevated risk for severe COVID-19 was similar for RA subgroups defined by serostatus or bone erosions.

Table 1.

Frequencies, proportions, and hazard ratios for COVID-19 outcomes, comparing all RA patients, and subgroups with or without RA-ILD, to matched comparators.

COVID-19 OutcomesAll RA Patients (n=582)RA-ILD (n=50)RA Patients without ILD (n=532)Comparators (n=2,892)Hospitalization, n (%)121 (21)24 (48)97 (18)402 (14)Unadjusted HR (95% CI)1.58 (1.27, 1.96)2.65 (1.71, 4.09)1.43 (1.12, 1.82)Ref.Adjusted* HR (95% CI)1.45 (1.14, 1.83)2.35 (1.38, 4.00)1.31 (1.00, 1.70)Ref.Death, n (%)26 (4)9 (18)17 (3)63 (2)Unadjusted HR (95% CI)1.72 (0.98, 3.01)5.88 (2.07, 16.71)1.13 (0.56, 2.29)Ref.Adjusted* HR (95% CI)1.24 (0.66, 2.32)13.94 (4.30, 45.18)0.75 (0.35, 1.63)Ref.Hospitalization or death, n (%)126 (22)25 (50)101 (19)419 (14)Unadjusted HR (95% CI)1.66 (1.33, 2.07)3.01 (1.93, 4.70)1.47 (1.14, 1.89)Ref.Adjusted* HR (95% CI)1.53 (1.20, 1.94)2.84 (1.64, 4.91)1.34 (1.02, 1.77)Ref.

*Adjusted for age, sex, race, and smoking

Figure 1.

Multivariable hazard ratios for the composite outcome of hospitalization or death from COVID-19, comparing all RA and subgroups by serostatus, bone erosions, and ILD to matched comparators without RA.

Conclusion

We confirmed that RA was associated with severe COVID-19 outcomes compared to the general population. We found evidence that ILD may be an effect modifier for the relationship between RA and severe COVID-19 outcomes, but RA subgroups defined by serostatus and bone erosions had similarly elevated risk. These findings suggest that ILD or its treatment may be a major contributor to severe COVID-19 outcomes in RA.

References

[1]Bongartz, T, et al, Arthritis Rheum. 2010 Jun;62(6):1583-91.

Disclosure of Interests

None declared

AB0624 Patients with vasculitis have a high prevalence of coronary microvascular dysfunction

Background

Vasculitides are a heterogenous group of diseases characterized by intense vessel wall inflammation, endothelial injury, and systemic inflammation. Several vasculitides are associated with high risk of cardiovascular (CV) disease, an important source of morbidity and mortality in this population. This excess CV risk is attributed both to a high burden of traditional risk factors and to inflammation, but this remains poorly studied. Indeed, inflammation is a known risk factor for CV disease and implicated in coronary microvascular dysfunction (CMD) which may precede obstructive coronary artery disease (CAD).

Objectives

We sought to assess whether vasculitis is associated with CMD in the absence of obstructive CAD.

Methods

We retrospectively identified subjects with systemic vasculitis who underwent symptom prompted rest/stress myocardial perfusion PET. Patients with an abnormal myocardial perfusion study (summed stress score ≥3) or LVEF<40% were excluded. Controls were identified from the same population and matched on age, gender and cardiovascular risk factors (CAD, hypertension, dyslipidemia, diabetes mellitus, and obesity). Coronary flow reserve (CFR), was calculated as the ratio of myocardial blood flow (ml/min/g) at peak stress compared to rest. CMD was defined as CFR <2.

Results

We studied 26 vasculitis cases and 66 matched controls. The most common vasculitides were giant cell arteritis (38%), ANCA-associated vasculitis (31%), and Takayasu’s arteritis (12%). Median (IQR) time between diagnosis and PET was 6.5 (2.9, 14.2) years. Seven (27%) cases had active vascultis at the time of PET. Cases and controls were well-matched on age, sex, and CV risk factors (Table 1). Despite a similar prevalence of CV risk factors, coronary flow reserve (reflected by CMD) was abnormal in 38% of vasculitis cases compared to 15% of controls (p=0.004). The mean [SD] CFR was 19% lower in vasculitis cases vs controls (2.11 [0.5] versus 2.6 [0.7], p=0.003).

Table 1.

The presence of coronary microvasculature dysfunction in patients with systemic vasculitis without obstructive coronary artery disease

Cohort characteristicsVasculitis (n=26)Control (n=66)P-valueAge at PET, years62 (18)61 (17)0.24Time from Vasculitis Diagnosis to PET, years (median, IQR)6.5 (2.9, 14.2)n/aFemale, n (%)18 (72%)43 (65%)0.99Vasculitis CharacteristicsLarge Vessel (e.g., giant cell arteritis, Takayasu’s), n(%)13 (50%)n/an/aMedium Vessel (e.g., polyarteritis nodosa, Kawasaki’s arteritis), n(%)2 (8%)n/an/aSmall Vessel (e.g., ANCA-associated vasculitis, Henoch-Schonlein Purpura), n(%)11 (42%)n/an/aCardiovascular Risk FactorsAt DiagnosisAt PETAt PETHypertension, n (%)12 (46%)20 (71%)47 (80%)0.47Obesity, n (%)3 (12%)2 (32%)2 (32%)0.84Diabetes, n (%)3 (12%)5 (20%)13 (20%)0.99Dyslipidemia, n (%)4 (15%)15 (58%)40 (61%)0.99Known CAD, n (%)0 (0%)1 (4%)1 (2%)0.48Imaging FindingsRest myocardial blood flow, ml/min/g1.0 (0.3)1.0 (0.3)0.8Stress myocardial blood flow, ml/min/g2.1 (0.6)2.6 (1.0)0.008Coronary Flow Reserve, ml/min/g*2.1 (0.5)2.6 (0.7)0.003Coronary Microvasculature Dysfunction** (CMD), n (%)10 (38%)11 (15%)0.004

Conclusion

Patients with systemic vasculitis, even in the absence of obstructive CAD, have a high prevalence of CMD compared with non-vasculitis patients. These differences were observed despite matching cases and controls on traditional CV risk factors, highlighting the importance of other factors, such as inflammation and vasculitis treatments on CMD and CV disease in this population. CMD is a known independent risk factor for CV mortality. Future prospective studies are needed to understand the relationship between vasculitis, systemic inflammation, and CMD.

Disclosure of Interests

None declared

Thank you for biting: dispersal of beneficial microbiota through 'antagonistic' interactions

Multicellular organisms harbor populations of microbial symbionts; some of these symbionts can be dispersed through the feeding activities of consumers. Studies of consumer-mediated microbiota dispersal generally focus on pathogenic microorganisms; the dispersal of beneficial microorganisms has received less attention, especially in the context of 'antagonistic' trophic interactions (e.g., herbivory, parasitism, predation). Yet, this 'trophic transmission' of beneficial symbionts has significant implications for microbiota assembly and resource species (e.g., prey) health. For example, trophic transmission of microorganisms could assist with environmental acclimatization and help resource species to suppress other consumers or competitors. Here, we highlight model systems and approaches that have revealed these potential 'silver-linings' of antagonism as well as opportunities and challenges for future research.

POS1428 VALIDATION OF ANCA-ASSOCIATED VASCULITIS AS THE CAUSE OF END-STAGE RENAL DISEASE IN THE UNITED STATES RENAL DATA SYSTEM

Background:

Glomerulonephritis and other renal manifestations are common in ANCA-associated vasculitis (AAV). Renal involvement in AAV is associated with adverse outcomes, including end-stage renal disease (ESRD) in up to 25% of patients (1). The United States Renal Data System (USRDS), a national registry of ESRD patients, represents a unique nationwide data source for studying AAV patients with ESRD. Prior research has assessed how often patients with ESRD attributed to AAV have biopsy-proven glomerulonephritis in USRDS (2), but the validity of the diagnosis of AAV as the cause of ESRD in the USRDS remains unknown.

Objectives:

We aim to validate the diagnosis of AAV as the primary cause of ESRD listed in USRDS.

Methods:

We identified all patients in the Mass General Brigham (MGB) healthcare system with a billing code for advanced chronic kidney disease or end-stage renal disease or procedure code for dialysis or renal transplantation. We identified all MGB patients fulfilling these criteria to records in the USRDS by name, sex, date of birth, and social security number. From this cohort of patients, we identified those with AAV or related diagnoses listed as the primary disease causing ESRD (ICD9: 446.0, 446.4 or ICD10: M31.3X, M31.7). Two authors reviewed medical records to collect information on whether or not a physician had diagnosed AAV, details of AAV history, renal and non-renal biopsies, and antineutrophil cytoplasmic antibody (ANCA) tests. Discrepancies were resolved through consensus. Details regarding initial ESRD onset date were obtained from the USRDS. To calculate the positive predictive value (PPV) for AAV as the primary cause of ESRD a definite physician diagnosis of AAV (a diagnosis confirmed by two physicians based on available data) in the MGB medical record was used as the gold standard. To calculate sensitivity, we linked the Partners (MGB) AAV Cohort to USRDS records using the same methods. A diagnosis code of AAV as the cause of ESRD was considered a true positive and a diagnosis code for other types of nephritis was considered a false negative.

Results:

We identified 89 USRDS records linked to MGB medical records in which the primary cause of ESRD was attributed to AAV. Of these, 85 were confirmed to be true cases of AAV after medical record review (PPV=96%) (Table 1). Among the cases classified as AAV, 84 (99%) had a positive ANCA test, which was predominantly MPO/P-ANCA (47, 55%); 36 (42%) had a renal biopsy, all of which were supportive of the diagnosis. The majority of cases were identified as AAV by ICD9 or 10 codes for Wegener’s granulomatosis (446.4 or M313.1). Within the Partners (MGB) AAV cohort linked to USRDS records, 33 (55%) of 60 identified cases had AAV listed as the cause of ESRD; in the remainder, ESRD was attributed to non-specific nephritis codes.

Table 1.

AAV and non-AAV patients in the USRDS with ESRD due to AAV (N=89)

Physician-Diagnosed AAV(N=85)ANCA type n (%)84 (98.8)MPO/P-ANCA+47 (55.3)PR3/C-ANCA+33 (38.8)Renal biopsy n (%)36 (42.4)Pauci-Immune Glomerulonephritis n (%)16 (44%)Non-renal biopsy n (%) Yes10 (11.8) No74 (87.1)Years from AAV diagnosis to ESRD median [IQR]1 [0, 6]Principal diagnosis code (ICD9/ICD10) n (%) Wegener’s granulomatosis (446.4, 446.4B, or M313.1)81 (95.3)

Conclusion:

We found that the diagnosis of AAV as the primary cause of ESRD in the USRD had a high PPV, suggesting accurate classification of ESRD due to AAV in the USRDS, but that sensitivity was moderate. These findings support the past and future use of the USRDS for research with ESRD attributed to AAV.

References:

[1]Moiseev S, Novikov P, Jayne D, Mukhin N. End-stage renal disease in ANCA-associated vasculitis. Nephrol Dial Transplant. 2017;32(2):248-53.

[2]Layton JB, Hogan SL, Jennette CE, Kenderes B, Krisher J, Jennette JC, et al. Discrepancy between Medical Evidence Form 2728 and renal biopsy for glomerular diseases. Clin J Am Soc Nephrol. 2010;5(11):2046-52.

Disclosure of Interests:

None declared

POS1174 HYPERINFLAMMATION AND CLINICAL OUTCOMES FOR PATIENTS WITH SYSTEMIC RHEUMATIC DISEASES HOSPITALIZED FOR COVID-19: A COMPARATIVE COHORT STUDY

Background:

COVID-19 can induce a hyperinflammatory state resulting in cytokine storm, which can lead to poor outcomes. Patients with systemic rheumatic diseases may be at increased risk for respiratory failure with COVID-19. Therefore, we investigated the relationship between rheumatic disease, hyperinflammation, and clinical outcomes among hospitalized COVID-19 patients.

Objectives:

To compare laboratory values, hyperinflammation, and clinical outcomes of hospitalized COVID-19 rheumatic patients and matched comparators.

Methods:

We performed a comparative cohort study of patients with polymerase chain reaction (PCR)-confirmed COVID-19 requiring hospitalization between 3/1/20-7/7/20 at a large health care system. We compared each systemic rheumatic disease case to up to 5 matched (by age, sex, and date of +SARS-CoV-2 PCR) comparators without systemic rheumatic disease. We extracted laboratory values from their hospitalization to compare peaks/troughs of individual laboratory results by case status and derived the COVID-19-associated hyperinflammation score (cHIS), a composite of 6 laboratory domains (0-6, ≥2 indicating hyperinflammation), as previously developed1. We used multivariable logistic regression to estimate ORs for COVID-19 outcomes by hyperinflammation and case status.

Results:

We identified 57 hospitalized rheumatic disease cases (mean age 67 years, 67% female) and 232 matched comparators hospitalized with PCR-confirmed COVID-19. Among cases, 26 (46%) had rheumatoid arthritis and 14 (25%) had systemic lupus erythematosus. Most cases (34, 60%) had active rheumatic disease. At baseline, 15 (27%) of cases were treated with biologic DMARDs, and 32 (56%) were using glucocorticoids. We analyzed 39,900 total laboratory results (median 85 per patient). Cases had higher peak neutrophil-to-lymphocyte ratio (9.6 vs 7.8, p=0.02), LDH (421 vs 345 U/L, p=0.04), creatinine (1.2 vs 1.0 mg/dL, p=0.01), and BUN (31 vs 23 mg/dL, p=0.03) than comparators but similar peak CRP (149 vs 116 mg/L, p=0.11, Figure 1). Cases had higher peak median cHIS (3 vs 2, p=0.01). Peak cHIS ≥2 had higher odds of intensive care unit (ICU) admission (OR 3.45, 95%CI 1.98-5.99), mechanical ventilation (OR 66.0, 95%CI 9.0-487.8), and mortality (OR 16.4, 95%CI 4.8-56.4) compared to cHIS <2 (Table 1). Cases had increased risk of ICU admission (OR 2.0, 95%CI 1.1-3.7) and mechanical ventilation (OR 2.7, 95%CI 1.4-5.2) than comparators.

Table 1.

Associations of peak cHIS and systemic rheumatic disease with COVID-19 hospitalization outcomes

Intensive care unit admissionMechanical ventilationDeath%Adjusted OR (95%CI)%Adjusted OR (95%CI)%Adjusted OR (95%CI)Hospitalization outcomes by hyperinflammation on cHIS1cHIS <2 (n=112)21%1.0 (Ref)1%1.0 (Ref)3%1.0 (Ref)cHIS ≥2 (n=177)48%3.5 (2.0-6.0)37%66.2 (9.0-487.8)27%16.4 (4.8-56.4)Hospitalization outcomes by rheumatic disease statusComparators (n=232)30%1.0 (Ref)19%1.0 (Ref)16%1.0 (Ref)Rheumatic cases (n=57)51%1.87 (1.03-3.40)39%2.46 (1.30-4.67)21%1.32 (0.61-2.88)

Matching factors: age, sex, and date of +PCR.

1Adjusted for age, sex, and case status.

2Adjusted for race, smoking, comorbidities, and body mass index.

cHIS, COVID-19-associated hyperinflammation score; CI, confidence interval; OR, odds ratio; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Conclusion:

Patients with systemic rheumatic disease hospitalized for COVID-19 had higher risk for hyperinflammation, kidney injury, and mechanical ventilation than non-rheumatic comparators. We validated the cHIS in our cohort, which was strongly associated with poor COVID-19 outcomes. These findings highlight that hospitalized patients with rheumatic diseases may be vulnerable to poor COVID-19 outcomes.

References:

[1]Webb BJ et al. Clinical criteria for COVID-19-associated hyperinflammatory syndrome. Lancet Rheumatol. 2020 Dec;2(12):e754-e763.

Disclosure of Interests:

Tiffany Hsu: None declared, Kristin D’Silva: None declared, Naomi Serling-Boyd: None declared, Jiaqi Wang: None declared, Alisa Mueller: None declared, Xiaoqing Fu: None declared, Lauren Prisco: None declared, Lily Martin: None declared, Kathleen Vanni: None declared, Alessandra Zaccardelli: None declared, Claire Cook: None declared, Hyon Choi Consultant of: Dr. Choi reports consultancy fees from Takeda, Selecta, GlaxoSmithKline, and Horizon, Grant/research support from: Dr. Choi reports research support from AstraZeneca., Yuqing Zhang: None declared, Ellen Gravallese: None declared, Zachary Wallace Consultant of: Dr. Wallace reports consulting fees from Viela Bio and MedPace., Grant/research support from: Dr. Wallace reports research support from Bristol-Myers Squibb and Principia., Jeffrey Sparks Consultant of: Dr. Sparks reports consultancy fees from Bristol-Myers Squibb, Gilead, Inova, Janssen, Optum, and Pfizer., Grant/research support from: Dr. Sparks reports research support from Amgen and Bristol-Myers Squibb.

Prolonged SARS-CoV-2 Illness in a Patient Receiving Ocrelizumab for Multiple Sclerosis

We describe a case of prolonged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a patient receiving ocrelizumab for multiple sclerosis. Viral RNA shedding, signs, and symptoms persisted for 69 days with resolution after administration of convalescent plasma and antiviral therapy. This case suggests risk for persistent SARS-CoV-2 infection in patients treated with anti-CD-20 monoclonal antibodies and supports a role for humoral immunity in disease resolution.

DDEL-07. A PHASE I STUDY EXAMINING THE FEASIBILITY OF INTERMITTENT CONVECTION-ENHANCED DELIVERY (CED) OF MTX110 FOR THE TREATMENT OF CHILDREN WITH NEWLY DIAGNOSED DIFFUSE MIDLINE GLIOMAS

Convection-enhanced delivery (CED, the infusion of drugs under controlled pressure to the brain parenchyma via targeted micro-catheters, allows accurate anatomical targeting and delivery of higher (therapeutic) drug concentrations through clinically relevant volumes of brain tissue or tumor. Histone deacetylase inhibitors have been found in vitro to be the most active agents against Diffuse Midline Gliomas (DMGs) Using a novel device (implantable subcutaneous pump connected with catheter directly implanted into the pons/thalamus) we are performing a Phase I safety study of repeated infusions of MTX110 (MTX110, Midatech) in a dose escalation manner. Eligible patients include 3–18 years of age with newly diagnosed DMGs following radiation therapy without evidence of hemorrhage or cysts with intact organ function. Patients undergo a tumor biopsy and a single catheter (Spetzler lumbar shunt catheter, Integra, Plainsboro, NJ) is placed stereotactically into the geometric center of the tumor. A second catheter is inserted subcutaneously with the distal tubing connected to the infusion pump, (SynchroMed II (Medtronic)), also inserted subcutaneously. The infusion pump is prefilled with MTX110 and administered using wireless N’Vison Clinical programmer into two 24-hour infusions, consisting of 20 hours of drug infusions at 0.2mL/hr. The pulse is completed 7 days later. This is a dose escalation study with the infusate consisting of gadolinium and MTX110 (30, 60, or 90 microM). The study describing the first use in children of this device for direct-to-tumor drug delivery is open to recruitment (January 2020) and the preliminary data will be available for presentation by June 2020.

Cook's Hernia: Renal Tumor Parasitic Vessels Herniating into Right Inguinal Canal

We report the incidental findings and management of a hernia whose contents included renal tumor parasitic vessels in a 52-year-old male who presented with a 22 cm large right renal tumor. His initial complaints were right sided fullness and hematuria. Incidentally on CT scan, the patient's large right renal mass was identified, as well as lower pole parasitic tumor vessels which were herniating into the patient's right inguinal canal. Parasitic tumor vessels are often found on larger obscure tumors. Few side effects or associated problems have been reported from issues with the parasitic vessels other than excessive bleeding. Never before, to our knowledge, has an inguinal hernia with renal mass parasitic vessels herniating into it been documented. We named the hernia after the general surgeon, Dr. Craig Cook, MD, FACS, who assisted during the open radical nephrectomy and who reduced and repaired the right inguinal hernia. We present a case presentation and treatment rationale for this tumor and associated parasitic vessels herniation, along with a brief re view of existing literature.

SUN-LB47 Extended Release Octreotide Pharmacokinetics in Healthy Subjects After Subcutaneous Injection of MTD201

An open-label, randomised, single-dose Phase I study in healthy subjects evaluated octreotide pharmacokinetics after deep-intramuscular (IM) or subcutaneous (SC) injection of MTD201 (30mg). All subjects received Sandostatin^® (100μg immediate release; SIR) by deep SC injection 24h before MTD201. MTD201 is manufactured by Q-Sphera™ printing technology to minimize particle size variation and afford simpler reconstitution and less painful injection via a 21G needle. Plasma octreotide concentrations were measured over 63 days to ascertain the potential for a 6- to 8-week dosing interval. MTD201 is being developed as a next generation long-acting somatostatin analogue for maintenance management of acromegaly and neuroendocrine cancer patients. Methods: 28 healthy subjects were randomised to two groups. The reference product SIR (100μg) was injected SC, followed 24 hours later by MTD201 administered by either IM (n=14, 38mm 21G needle) or SC (n=14, 16mm 21G needle) injection. MTD201 was resuspended in WFI to give a final injection volume of 1.5mL. Plasma samples for determination of octreotide and serum samples for IGF-1 and GH levels were drawn pre-dose and over the 63-days post-dosing. Injection site reactions and AEs were recorded, scored and compared across groups. Results: MTD201 was very well tolerated by both groups with 3 mild TEAEs observed per group. Transient and mild injection site reactions were similar after all treatments. Upon MTD201 injection, a low initial burst of octreotide (<1ng/mL) was followed by a sustained period of release that extended beyond the final sampling point at Day 63. C_max values of 5.42ng/mL (SC) and 3.68ng/mL (IM) were within the plasma exposure range reported for marketed octreotide products. Octreotide bioavailability was 47% (IM) and 62% (SC) relative to SIR. Sustained suppression of IGF-1 concentration was achieved throughout the study period to similar levels for both groups. Octreotide PK profiles and overall exposures were similar between groups, indicating that these routes may be interchangeable in clinical use.Conclusions: MTD201 (30mg) by either IM or SC injection produced continuous octreotide release over a period of at least 63 days at levels predicted to maintain efficacious plasma concentrations at steady state with a dosing interval of up to 8 weeks. Reduced plasma IGF-1 concentrations were maintained throughout the study period. Unlike marketed octreotide depot products, MTD201 can be simply and rapidly reconstituted in WFI to give a stable suspension injectable via 21G needle in a 1.5mL volume. MTD201 can be developed as an easy to inject SC or IM depot for acromegaly and NETs, with an expected dose interval of 8 weeks, and confirmed patient-centric advantages.

Determination of Glyphosate and Aminomethylphosphonic Acid in Crops by Capillary Gas Chromatography with Mass-Selective Detection: Collaborative Study

A collaborative study was conducted to validate a method for the determination of glyphosate and aminomethylphosphonic acid (AMPA) in crops. The analytes are extracted from crops with water, and the crude extracts are then subjected to a cation exchange cleanup. The analytes are derivatized by the direct addition of the aqueous extract into a mixture of heptafluorobutanol and trifluoroacetic anhydride. The derivatized analytes are quantitated by capillary gas chromatography with mass-selective detection (MSD). The collaborative study involved 13 laboratories located in 5 countries 12 laboratories returned valid data sets. The crops tested were field corn grain, soya forage, and walnut nutmeat at concentrations of 0.050, 0.40, and 2.0 mg/kg. The study used a split-level pair replication scheme with blindly coded laboratory samples. Twelve materials were analyzed, including 1 control and 3 split-level pairs for each matrix, 1 pair at each nominal concentration. For glyphosate, the mean recovery was 91%, the average intralaboratory variance, the repeatability relative standard deviation (RSDr), was 11%, and the interlaboratory variance, the reproducibility relative standard deviation (RSDR), was 16%. For AMPA, the mean recovery was 87%, the RSDr was 16%, and the RSDR was 25% at mg/kg levels.

Gut microbiome alteration in MORDOR I: a community-randomized trial of mass azithromycin distribution

The MORDOR I trial1, conducted in Niger, Malawi and Tanzania, demonstrated that mass azithromycin distribution to preschool children reduced childhood mortality1. However, the large but simple trial design precluded determination of the mechanisms involved. Here we examined the gut microbiome of preschool children from 30 Nigerien communities randomized to either biannual azithromycin or placebo. Gut microbiome γ-diversity was not significantly altered (P = 0.08), but the relative abundances of two Campylobacter species, along with another 33 gut bacteria, were significantly reduced in children treated with azithromycin at the 24-month follow-up. Metagenomic analysis revealed functional differences in gut bacteria between treatment groups. Resistome analysis showed an increase in macrolide resistance gene expression in gut microbiota in communities treated with azithromycin (P = 0.004). These results suggest that prolonged mass azithromycin distribution to reduce childhood mortality reduces certain gut bacteria, including known pathogens, while selecting for antibiotic resistance.

Performance measurement of a Canadian provincial tuberculosis programme: Manitoba, 2008-2012

BACKGROUND

Performance measurement assists tuberculosis (TB) programmes in understanding areas of strength and weakness, and planning for improvements. Canada currently does not have a national comprehensive system for the measurement and analysis of TB programme performance.

OBJECTIVE

To analyse the performance of a Canadian provincial TB programme using measures and targets based on those published by the US Centers for Disease Prevention and Control for 2015.

DESIGN

Using provincial surveillance data from the Canadian province of Manitoba, we analysed key programme performance outcome measures (treatment completion, early detection, human immunodeficiency virus [HIV] testing, paediatric TB, retreatment, and contact elicitation and assessment) for people diagnosed with TB between 2008 and 2010.

RESULTS

Significant outcome variation was found between Indigenous and non-Indigenous populations as well as within populations. The reporting rate of HIV testing was low. High rates of paediatric TB among Indigenous populations, particularly in rural areas, were found. Significantly better performance in HIV testing and reporting as well as in contact investigation was found for rural compared with urban Indigenous populations. Foreign-born persons had the lowest contact assessment rate.

CONCLUSION

This study of TB programme performance in Manitoba demonstrates the viability of the approach in the Canadian context, and could help to identify key areas for TB programme improvement.

SAT-432 MTD201 Has a Favourable 28-Day Sustained Release Profile Compared to Sandostatin LAR in Healthy Subjects

A double-blind, randomised, single-dose parallel group study was performed to compare the tolerability, pharmacokinetics and pharmacodynamics of MTD201 30 mg octreotide (test product) and Sandostatin LAR 30 mg (reference product) in healthy subjects. MTD201 uses Q-Sphera™ printing technology to precisely control microparticle size, which facilitates simpler reconstitution and injection using smaller needle size than Sandostatin LAR (SLAR) or Somatuline Autogel. MTD201 is being developed for acromegaly and NETs as an alternative to these existing long-acting treatments. Methods: 24 male and female healthy subjects were randomised to receive a single, 30mg i.m. injection of MTD201 (N=12) using a 21G needle or Sandostatin LAR (N=12) using the pre-packed 19G needle. Plasma samples for determination of octreotide, growth hormone (GH) and IGF-1 concentrations were obtained throughout the 63-day period after injection. The plasma GH response to a GHRH+arginine challenge, an accepted surrogate efficacy endpoint for somatostatin analogues, was performed 7 days before octreotide dosing and repeated 28- and 45-days post-dose. Additional data were collected to check for presence of anti-octreotide antibodies and injection site reactions were scored regularly for 7 days post-injection. Results: Both treatments were well tolerated, with AEs consistent with octreotide treatment. Overall plasma octreotide exposures for the test and reference drugs were comparable whilst subjects receiving MTD201 illustrated lower initial spike in plasma octreotide (burst; 0.12ng/mL and 0.99ng/mL for MTD201 and SLAR, respectively), a more linear, consistent profile, and lower variability across the intended dose interval (28 days). Both treatment groups showed detectable plasma octreotide levels up to the final PK sampling point of 63 days. GH and IGF-1 suppression were highly comparable across treatments, with ≈25% and ≈30% reductions from baseline for both groups, respectively. Injection site reactions were less frequent and of lower severity in subjects who received MTD201. Specifically, pain at the injection site was observed in 8% (MTD201) and 25% (SLAR) of subjects, and injection site tenderness in 8% (MTD201) and 83% (SLAR) of subjects. Conclusions: MTD201 produced a safe and effective sustained-release profile of octreotide, supporting a once-monthly treatment interval, as is indicated for SLAR. Therapeutic octreotide concentrations and GH/IGF-1 suppression comparable with SLAR were achieved. Combined with the other advantages for MTD201 regarding smaller needle size, simpler and more reliable reconstitution and injection, these results warrant further study in a suitably powered clinical trial to formally establish MTD201 as an alternative long-acting somatostatin analogue product.

A novel radiographic method to facilitate measurement of the tibial plateau angle in dogs

The tibial plateau levelling osteotomy (TPLO) is commonly performed for treatment of cranial cruciate ligament deficiency in dogs. In order to be performed as described, this procedure relies on consistent measurement of the tibial plateau angle (TPA) on radiographs. This prospective study compared two radiographic methods for subsequent TPA measurement with respect to measured angle and ease of determining landmarks for measurement as determined by four observers. One method was the accepted standard radiographic protocol outlined in the TPLO training seminars. The other method involved a novel split image radiographic protocol not yet described in the literature. Participants' subjective scores as to ease of identifying landmarks and determining TPA on radiographs for each method were evaluated. Inter-observer TPA measurement variability was also assessed for each method. The novel radiographic method was judged to be significantly better in terms of ease of measuring TPA. Inter-observer measurement variability was considered appropriate for recommending use of this novel method for radiographing patients for TPA measurements.

Randomised controlled trial of prophylactic antibiotic treatment for the prevention of endophthalmitis after open globe injury at Groote Schuur Hospital

BACKGROUND/AIMS

Most post-traumatic acute infectious endophthalmitis occur within a week of open globe trauma, necessitating early antibiotic prophylaxis. There are few randomised studies that demonstrate the benefits of prophylactic antibiotics. This randomised controlled non-inferiority trial was aimed at determining the incidence of post-traumatic endophthalmitis using established intravenous/oral prophylaxis and comparing this to the incidence using oral antibiotics only.

METHODS

All adult patients admitted with open globe injury were included. Those with proven endophthalmitis, high-risk features, who underwent primary evisceration and those allergic to the trial antibiotics were excluded. Patients were randomised to receive either intravenous cefazolin and oral ciprofloxacin or oral ciprofloxacin and oral cefuroxime for 3 days from admission. Acute endophthalmitis was the primary outcome. Patients completed the study if they were followed up for 6 weeks post injury.

RESULTS

Three hundred patients were enrolled, with 150 in each arm. There were 99 exclusions. Seven patients developed endophthalmitis despite prophylaxis-2.0% (three cases) in the intravenous and oral arm, compared with 2.7% (four cases) in the oral-only arm-this difference was not statistically significant (p=0.703).

CONCLUSIONS

The incidence of endophthalmitis with prophylaxis was 2-3%. Selected patients with open globe injuries (without high-risk features) may receive either intravenous cefazolin and oral ciprofloxacin, or oral cefuroxime and oral ciprofloxacin as prophylaxis against acute endophthalmitis-the latter regimen has the advantage of shortening patients' hospital stays and reducing costs. Non-inferiority study-design limitations should be taken into account, however.

Acute appendicitis in South Africa: a systematic review

BACKGROUND

Acute appendicitis is one of the most common surgical emergencies in the West. A large body of research is investigating the risk factors for disease and perforation. As South Africa has a social environment, health system structure, and population demography unique from developed nations, the findings may not be generalisable to this setting. A systematic review has not been performed for appendicitis research in South Africa. The objective of this review was to systematically examine the literature on appendicitis in South Africa.

METHOD

Published articles discussing appendicitis in South Africa up to March 2014 were identified using MEDLINE and EBMReviews. Research themes were analysed in the literature. Perforation rates, mortality, negative appendicectomy rates and gender differences were analysed from audits of patients undergoing appendicectomy for acute appendicitis.

RESULTS

Ten audits were included in the quantitative analysis. Some were excluded in the subgroup analyses. Negative appendicectomies occurred at a rate of 17% (580/3 354). Women were more likely to have a negative appendicectomy than men (28% vs. 9%, p < 0.01). The perforation rate for appendicectomy patients was 36% (970/2 688), and mortality rate was 1% (36/2 946). Research efforts focused on investigating differential incidence and outcomes between racial groups within the country.

CONCLUSION

Appendicitis trends in South Africa are consistent with those in developing regions. However, there is lack of research from the private sector. Further research is needed to investigate specific factors which delay care, outcomes and cost analyses for laparoscopic surgery, and the system strengthening of surgical services at district hospitals.

Influence of active recovery on professional rugby union player's ability to harness postactivation potentiation

AIM

After postactivation potentiation (PAP) has been induced, current research recommends that, on average, an 8 minute passive recovery period is applied before engaging in subsequent dynamic exercise. However, given the importance of maximizing time usage during the warm-up of elite athletes, it is likely that further exercise would be incorporated into this time frame. This study aimed to examine the effects of passive and active recovery on the ability to utilize PAP.

METHODS

In a randomised and counter balanced design, 36 professional rugby union players completed two experimental trials involving a baseline countermovement jump (CMJ), followed by a PAP stimulus (3 x 3 repetitions at 87% of 1-RM back squat) and CMJ retesting after 8 minutes of passive or active recovery. The active recovery involved subjects performing ballistic bench throws (1 x 3 repetitions at 30% 1-RM bench press) 4 minutes after the lower body PAP stimulus. Data presented as mean±SD.

RESULTS

Baseline peak power output (PPO) was not different between conditions (P=0.61). CMJ PPO increased from baseline under both conditions, however the delta (mean±SD; passive +161±127 vs. active +116±44 W; P=0.03) and % change (passive 3.3±2.8 vs. active 2.3±0.9 %; P=0.03) in PPO was greater after the passive recovery, when compared to the active recovery.

CONCLUSION

In conclusion, the passive and active recovery periods both led to increases in lower-body PPO, nevertheless, the passive recovery elicited the greatest performance changes. However, the active recovery is a more practical option for athletes, as it maximizes time usage during warm-up.