Persistent Titers Research Articles

Leptospirosis in the Platypus (Ornithorhynchus anatinus) in Australia: Who Is Infecting Whom?

The platypus (Ornithorhynchus anatinus) is an amphibious, egg-laying mammal of high conservation value that is found only in Australia. The zoonotic bacterium Leptospira interrogans serovar Hardjo was discovered in platypuses in prior studies, but little is known about its epidemiology. Samples in the Platypus Serum Bank were tested in 2023 and the results were combined with historical records. Antibodies against L. interrogans serovar Hardjo were found in 50% of 464 serum samples from 411 platypuses collected from 14 river basins in southeastern Australia between 1981 and 2012; prevalence remained high over three decades in the Shoalhaven River population. Seroprevalence increased with age, suggesting environmental exposure. Individual platypuses had persistent titres, some for six years. Seropositive females lactated, juveniles were recruited into the population, and there were no reports of clinical leptospirosis. Three necropsied platypuses were seropositive and had mild nephritis with leptospires in the renal tubules. The high seroprevalence, persistent titres, lack of disease, mild renal lesions, and renal colonisation suggest the platypus may be a maintenance host. Sympatric cattle had L. interrogans serovar Hardjo titres, but the spatial association with seropositive platypuses was statistically weak. Other mammalian wildlife species and sheep also have L. interrogans serovar Hardjo titres; therefore, a complex ecological network must be considered. A landscape-wide study is recommended to properly assess transmission pathways and confirm who is infecting whom.

Circulating anti-nuclear autoantibodies in COVID-19 survivors predict long COVID symptoms.

Autoimmunity has been reported in patients with severe coronavirus disease 2019 (COVID-19). We investigated whether anti-nuclear/extractable-nuclear antibodies (ANAs/ENAs) were present up to a year after infection, and if they were associated with the development of clinically relevant post-acute sequalae of COVID-19 (PASC) symptoms. A rapid-assessment line immunoassay was used to measure circulating levels of ANAs/ENAs in 106 convalescent COVID-19 patients with varying acute phase severities at 3, 6 and 12 months post-recovery. Patient-reported fatigue, cough and dyspnoea were recorded at each time point. Multivariable logistic regression model and receiver operating curves were used to test the association of autoantibodies with patient-reported outcomes and pro-inflammatory cytokines. Compared to age- and sex-matched healthy controls (n=22) and those who had other respiratory infections (n=34), patients with COVID-19 had higher detectable ANAs at 3 months post-recovery (p<0.001). The mean number of ANA autoreactivities per individual decreased between 3 and 12 months (from 3.99 to 1.55) with persistent positive titres associated with fatigue, dyspnoea and cough severity. Antibodies to U1-snRNP and anti-SS-B/La were both positively associated with persistent symptoms of fatigue (p<0.028, area under the curve (AUC) 0.86) and dyspnoea (p<0.003, AUC=0.81). Pro-inflammatory cytokines such as tumour necrosis factor (TNF)-α and C-reactive protein predicted the elevated ANAs at 12 months. TNF-α, D-dimer and interleukin-1β had the strongest association with symptoms at 12 months. Regression analysis showed that TNF-α predicted fatigue (β=4.65, p=0.004) and general symptomaticity (β=2.40, p=0.03) at 12 months. Persistently positive ANAs at 12 months post-COVID are associated with persisting symptoms and inflammation (TNF-α) in a subset of COVID-19 survivors. This finding indicates the need for further investigation into the role of autoimmunity in PASC.

Pathogenesis of the obstetric antiphospholipid syndrome: the key role of beta 2 glycoprotein I

Antiphospholipid syndrome (APS) is defined by recurrent pregnancy morbidity and/or vascular thrombosis associated with the persistent presence of antibodies against anionic phospholipid-binding proteins. Beta 2 glycoprotein I (β2GPI) and prothrombin (PT) are the major antigens for antiphospholipid antibodies (aPL) detectable by functional coagulation [lupus anticoagulant (LA)] or solid-phase assays [anti-β2GPI-dependent cardiolipin (aCL) and anti-β2GPI]. β2GPI-dependent aPL are responsible for the positivity of the three classification laboratory criteria. While medium/high titers of antibodies against β2GPI are risk factors for both the vascular and the obstetric manifestations of APS, persistent low titers are also associated with pregnancy complications. There is evidence from animal models of aPL-dependent fetal loss and from in vitro systems that β2GPI-dependent aPL can be pathogenic. β2GPI is physiologically found in large quantities at the placental level being available for the specific antibodies circulating in the maternal blood. Once bound to the protein, the antibodies trigger a local inflammation via the activation of the complement cascade and affect trophoblast and decidual function. The final result is represented by defective placentation, while thrombotic events are apparently less important. β2GPI is a pleiotropic molecule with scavenging properties towards several molecules including apoptotic material and displays anti-oxidant activity. These functions may explain the β2GPI placental localization in an area of intensive tissue remodeling and low oxygen tension. Since β2GPI interacts also with the complement and the coagulation cascade, its binding with specific antibodies may affect the physiology of placentation in several ways.

Durable protection against the SARS-CoV-2 Omicron variant is induced by an adjuvanted subunit vaccine.

Despite the remarkable efficacy of COVID-19 vaccines, waning immunity and the emergence of SARS-CoV-2 variants such as Omicron represents a global health challenge. Here, we present data from a study in nonhuman primates demonstrating durable protection against the Omicron BA.1 variant induced by a subunit SARS-CoV-2 vaccine comprising the receptor binding domain of the ancestral strain (RBD-Wu) on the I53-50 nanoparticle adjuvanted with AS03, which was recently authorized for use in individuals 18 years or older. Vaccination induced neutralizing antibody (nAb) titers that were maintained at high concentrations for at least 1 year after two doses, with a pseudovirus nAb geometric mean titer (GMT) of 1978 and a live virus nAb GMT of 1331 against the ancestral strain but not against the Omicron BA.1 variant. However, a booster dose at 6 to 12 months with RBD-Wu or RBD-β (RBD from the Beta variant) displayed on I53-50 elicited high neutralizing titers against the ancestral and Omicron variants. In addition, we observed persistent neutralization titers against a panel of sarbecoviruses, including SARS-CoV. Furthermore, there were substantial and persistent memory T and B cell responses reactive to Beta and Omicron variants. Vaccination resulted in protection against Omicron infection in the lung and suppression of viral burden in the nares at 6 weeks after the final booster immunization. Even at 6 months after vaccination, we observed protection in the lung and rapid control of virus in the nares. These results highlight the durable and cross-protective immunity elicited by the AS03-adjuvanted RBD-I53-50 nanoparticle vaccine.

Inactivation rate of African swine fever virus by a formaldehyde-based product.

African swine fever (ASF) is an important transboundary animal disease with a high mortality rate. The high African swine fever virus (ASFV) titers in the excretion of infected wild boar possibly contaminate the feed ingredient. Once contaminated, it could support persistent residual titer of the ASFV. The chemical inactivation of imported feed ingredients is a precautionary risk management measure to restrict the import risk of ASFV through international trade. The log ASFV titers were linearly reduced as a function of the inactivation time after exposure to 0.03%, 0.05%, 0.1%, and 0.2% formaldehyde-based product (FBP). A four-log reduction of ASFV titer was achieved after exposure to 0.2% FBP and 0.03%-0.1% FBP for 30-min and 60-min inactivation times, respectively. The decimal reduction time or D value is defined as the time required to inactivate the virus titer by 1 log. The ASFV inactivation rate from the independent experiment of FBP concentration was converted to a D value. The observed mean D0.2%, D0.1%, D0.05%, and D0.03% of FBP were 13.4, 44.9, 45.0, and 45.3 min per log reduction of ASFV, respectively. The interpretation of D0.2% of FBP is that the ASFV titer is inactivated by 1 log after being exposed to 0.2% FBP for every 13.4 min. A more effective chemical has a lower D value because of a shorter inactivation time required to achieve the same 1-log reduction. In addition, the hypothetical inactivation time by any chemical additive is scenario-specific and is calculated by the product of D value (at a certain concentration) and log titers of residual ASFV. This study introduces the concept and application of the D value to compare the virucidal activity of chemicals and to determine the hypothetical inactivation time of chemicals depending on the chemical concentration including the virus titer in the feed.

CoVac501, a self-adjuvanting peptide vaccine conjugated with TLR7 agonists, against SARS-CoV-2 induces protective immunity

Safe, effective, and economical vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to achieve adequate herd immunity and end the pandemic. We constructed a novel SARS-CoV-2 vaccine, CoVac501, which is a self-adjuvanting peptide vaccine conjugated with Toll-like receptor 7 (TLR7) agonists. The vaccine contains immunodominant peptides screened from the receptor-binding domain (RBD) and is fully chemically synthesized. It has been formulated in an optimized nanoemulsion formulation and is stable at 40 °C for 1 month. In non-human primates (NHPs), CoVac501 elicited high and persistent titers of protective neutralizing antibodies against multiple RBD mutations, SARS-CoV-2 original strain, and variants (B.1.1.7 and B.1.617.2). Specific peptides booster immunization against the B.1.351 variant has also been shown to be effective in improving protection against B.1.351. Meanwhile, CoVac501 elicited the increase of memory T cells, antigen-specific CD8+ T-cell responses, and Th1-biased CD4+ T-cell immune responses in NHPs. Notably, at an extremely high SARS-CoV-2 challenge dose of 1 × 107 TCID50, CoVac501 provided near-complete protection for the upper and lower respiratory tracts of cynomolgus macaques.

Safety and efficacy of avalglucosidase alfa versus alglucosidase alfa in patients with late-onset Pompe disease (COMET): a phase 3, randomised, multicentre trial

Pompe disease is a rare, progressive neuromuscular disorder caused by deficiency of acid α-glucosidase (GAA) and accumulation of lysosomal glycogen. We assessed the safety and efficacy of avalglucosidase alfa, a recombinant human GAA enzyme replacement therapy specifically designed for enhanced mannose-6-phosphate-receptor targeting and enzyme uptake aimed at increased glycogen clearance, compared with the current approved standard of care, alglucosidase alfa, in patients with late-onset Pompe disease. We did a randomised, double-blind, phase 3 trial at 55 sites in 20 countries. We enrolled individuals (aged ≥3 years) with enzymatically confirmed late-onset Pompe disease who had never received treatment. We used a centralised treatment allocation system to randomly allocate participants to either avalglucosidase alfa or alglucosidase alfa. Participants and investigators were unaware of their treatment allocation. The primary outcome measure was change from baseline to week 49 in upright forced vital capacity percent (FVC%) predicted. We used a hierarchical fixed sequential testing strategy, whereby non-inferiority of avalglucosidase alfa compared with alglucosidase alfa was assessed first, with a non-inferiority margin of 1·1. If non-inferiority was seen, then superiority was tested with a 5% significance level. The key secondary objective was effect on functional endurance, measured by the 6-minute walk test (6MWT). Safety was assessed, including treatment-emergent adverse events and infusion-associated reactions. The modified intent-to-treat population was the primary analysis population for all efficacy analyses. The safety population was the analysis population for safety analyses. This trial is registered with ClinicalTrials.gov, NCT02782741. We report results of the 49-week primary analysis period. Between Nov 2, 2016, and March 29, 2019, 100 participants were randomly allocated avalglucosidase alfa (n=51) or alglucosidase alfa (n=49). Treatment with avalglucosidase alfa resulted in a least-squares mean improvement in upright FVC% predicted of 2·89% (SE 0·88) compared with 0·46% (0·93) with alglucosidase alfa at week 49 (difference 2·43% [95% CI -0·13 to 4·99]). Non-inferiority was shown because the lower bound of the 95% CI for the difference far exceeded the predefined non-inferiority margin but did not exclude 0 (p=0·0074). Superiority was not reached (p=0·063), so formal testing was stopped, as per the testing hierarchy. Improvements were also seen in the 6MWT with avalglucosidase alfa compared with alglucosidase alfa, with greater increases in distance covered (difference 30·01 m [95% CI 1·33 to 58·69]) and percent predicted (4·71% [0·25 to 9·17]). Treatment-emergent adverse events potentially related to treatment were reported in 23 (45%) of 51 participants in the avalglucosidase alfa group and in 24 (49%) of 49 in the alglucosidase alfa group, and infusion-associated reactions were reported in 13 (26%) participants in the avalglucosidase alfa group and 16 (33%) in the alglucosidase alfa group. Of the five trial withdrawals, all in the alglucosidase alfa group, four were due to adverse events, including two infusion-associated reactions. Serious treatment-emergent adverse events were reported in eight (16%) participants who received avalglucosidase alfa and in 12 (25%) who received alglucosidase alfa. One participant treated with alglucosidase alfa died because of acute myocardial infarction determined to be unrelated to treatment. Antidrug antibody responses were similar in both groups. High and persistent titres (≥12 800) and neutralising antibodies were more common with alglucosidase alfa (in 16 [33%] participants) than with avalglucosidase alfa (ten [20%]). We consider that this study provides evidence of clinically meaningful improvement with avalglucosidase alfa therapy over alglucosidase alfa in respiratory function, ambulation, and functional endurance, with no new safety signals reported. An open-label extended-treatment period is ongoing to confirm the long-term safety and efficacy of avalglucosidase alfa, with the aim for this therapy to become the new standard treatment in late-onset Pompe disease. Sanofi Genzyme.

Skin Erosions in a Newborn.

Skin Erosions in a Newborn.

Antiphospholipid Antibody Assays in 2021: Looking for a Predictive Value in Addition to a Diagnostic One.

Antiphospholipid antibodies (aPL) are mandatory for the diagnosis but are also a risk factor for the antiphospholipid syndrome (APS) clinical manifestations. Lupus anticoagulant (LA), anticardiolipin (aCL), and anti-beta2 glycoprotein I (β2GPI) assays are the formal laboratory classification/diagnostic criteria. Additional nonclassification assays have been suggested; among them, antiphosphatidylserine-prothrombin (aPS/PT) and antidomain 1 β2GPI antibodies are the most promising ones although not yet formally accepted. aPL represent the example of a laboratory test that moved from dichotomous to quantitative results consistent with the idea that reporting quantitative data offers more diagnostic/prognostic information for both vascular and obstetric manifestations. Although the general rule is that the higher the aPL titer, the higher the test likelihood ratio, there is growing evidence that this is not the case for persistent low titers and obstetric events. LA displays the highest diagnostic/prognostic power, although some isolated LAs are apparently not associated with APS manifestations. Moreover, isotype characterization is also critical since IgG aPL are more diagnostic/prognostic than IgA or IgM. aPL are directed against two main autoantigens: β2GPI and PT. However, anti-β2GPI antibodies are more associated with the APS clinical spectrum. In addition, there is evidence that anti-β2GPI domain 1 antibodies display a stronger diagnostic/prognostic value. This finding supports the view that antigen and even epitope characterization represents a further step for improving the assay value. The strategy to improve aPL laboratory characterization is a lesson that can be translated to other autoantibody assays in order to improve our diagnostic and prognostic power.

Management of patients with chronic lymphocytic leukemia during the SARS-CoV-2 pandemic.

Oncohematological patients are prone to develop infections due to immunosuppression caused by the disease and chemo-immunotherapy. The aim of this review was to outline the details of the management of patients with chronic lymphocytic leukemia (CLL) during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Patients with CLL often exhibit inadequate humoral and cellular immune responses to various infections and vaccinations. Patients under the ‘watch and wait’ strategy have a lower risk of infections, including with SARS-CoV-2, compared with those undergoing therapeutic interventions, but they still have a higher risk than age-matched controls. Patients with CLL have a high risk of developing severe forms of coronavirus disease-2019 (COVID-19), particularly if they are undergoing chemo-immunotherapy. The total anti-SARS-CoV-2 antibody titer demonstrates a slower increase in patients with CLL infected with the virus, and the antibody levels tend to decrease after reaching a maximum level sooner than in healthy individuals. This leads to a late negativation of the PCR tests and a longer duration of hospitalization. In total, ~1/3 of patients with CLL do not develop a persistent titer of antiviral antibodies, and this is associated with the presence of hypogammaglobulinemia. It appears that patients with CLL have the worst outcomes amongst patients with malignant hemopathies and SARS-CoV-2 infection. Bruton tyrosine kinase inhibitors reduce the hyperinflammatory status of patients with CLL with COVID-19, which is accompanied by decreased levels of serum inflammatory markers, ferritin and D-dimer, and serum levels of pro-inflammatory cytokines, but they increase the risk of infections and impaired humoral immunity. An abrupt discontinuation of these may promote the rapid decompensation of CLL, which may even mimic the clinical manifestations of COVID-I9, including a significant increase in cytokine release. In conclusion, therapeutic decisions must be personalized to each patient with CLL and each at risk patient must be quarantined during the SARS-CoV-2 pandemic to reduce their risk of contraction.

Eculizumab for Refractory Thrombosis in Antiphospholipid Syndrome

Introduction:Antiphospholipid syndrome (APS) is characterized by arterial and/or venous thrombosis in the presence of antiphospholipid antibodies. Recently, derangement in the complement pathway has been implicated in APS pathophysiology. Refractory cases of APS with recurrent and potentially fatal thrombosis have prompted use of the monoclonal antibody eculizumab, which inhibits generation of the terminal complement complex. We present the successful use of eculizumab in controlling and preventing recurrent thrombosis in a refractory case of APS. Case Description:An 18-year-old female received a diagnosis of antiphospholipid syndrome after developing extensive unprovoked deep vein thrombosis of axillary, inferior vena caval and brachiocephalic veins. Thrombophilia evaluation revealed triple positivity for lupus anti-coagulant (LA), beta-2 glycoprotein I (GP) IgG 84.9 SGU Units, IgM 76.5 SMU Units, IgA 66.7 SAU Units and strongly positive anti-cardiolipin (aCL) antibodies (each &amp;gt;&amp;gt;40U/mL) with persistent positive titers after 12 weeks of initial evaluation. She was refractory with trials of multiple anticoagulants alone and with antiplatelet and adjunctive therapies. Anticoagulants used were enoxaparin, fondaparinux, apixaban, rivaroxaban, and warfarin; antiplatelet agents used were aspirin and clopidogrel; and adjunctive therapies included hydroxychloroquine, immunosuppression with steroids and rituximab, and plasmapheresis. Despite these interventions, she continued to develop recurrent thrombosis of subclavian, femoral, common femoral, iliac, popliteal and saphenous veins. She additionally developed a potentially life-threatening hepatic infarction and pulmonary embolism, and 6 weeks of plasma exchange failed to decrease antiphospholipid antibody titers. Following this event, eculizumab (600mg weekly x 4 weeks, followed by 900mg once on week 5, followed by 900mg every 2 weeks) was initiated in combination with fondaparinux, aspirin, clopidogrel, and hydroxychloroquine. She has remained on this regimen with additional anticoagulation and antiplatelet therapy without recurrence of thrombosis over the subsequent year. Discussion:Recent evidence has shown complement activation playing a role in pathophysiology of antiphospholipid syndrome. This is thought to occur through C3 and C5a causing platelet and endothelial activation, leading to microvascular thrombosis. Histological evidence of such processes is supported by the demonstration of anti-beta-2 GP1 IgG-C5b-9 immune complexes in microvascular organ thrombi in individuals with APS leading to thrombotic microangiopathy and multiorgan failure. Such evidence of complement induced thrombosis in antiphospholipid syndrome led us to use eculizumab following failure of available therapies including anticoagulation, antiplatelet therapy, immune modulation and plasmapheresis in a potentially life-threatening event. Absence of recurrent thrombotic events over approximately one year with eculizumab combined with anticoagulation and antiplatelet therapy highlights the potential role of complement inhibition in preventing thrombosis in APS. While the role of complement in thrombosis continues to be elucidated, we have observed no decline in antiphospholipid antibody levels in a span of one year in our patient. Importantly, there has been no recurrent thrombosis during this time. Our case suggests that eculizumab may have a role as a therapeutic option in refractory thrombosis in APS. Chronology of Events:Eculizumab initiated on 9/5/2019. No evidence of venous or arterial thrombosis since 10/2019 to present. Figure Disclosures Tarantino: Pfizer:Other;Genentech:Membership on an entity's Board of Directors or advisory committees;Octapharma:Membership on an entity's Board of Directors or advisory committees;Dova:Membership on an entity's Board of Directors or advisory committees;CDC:Membership on an entity's Board of Directors or advisory committees;Grifols:Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Amgen:Membership on an entity's Board of Directors or advisory committees;Biomarin:Membership on an entity's Board of Directors or advisory committees;NovoNordisk:Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau;Takeda:Research Funding;HRSA:Membership on an entity's Board of Directors or advisory committees;Spark:Membership on an entity's Board of Directors or advisory committees;Sobi:Membership on an entity's Board of Directors or advisory committees.McCrae:Rigel:Consultancy;Novartis:Honoraria;Momenta Pharmaceuticals:Consultancy;Dova:Consultancy.Chaturvedi:Sanofi:Honoraria, Membership on an entity's Board of Directors or advisory committees;Alexion:Honoraria, Membership on an entity's Board of Directors or advisory committees.Roberts:Octapharma:Consultancy, Speakers Bureau;uniQure:Consultancy;Sanofi:Consultancy, Speakers Bureau;Novo Nordisk:Consultancy, Speakers Bureau;Pfizer:Consultancy;Takeda:Consultancy, Research Funding, Speakers Bureau. OffLabel Disclosure: eculizumab for treatment of refractory thrombosis in antiphospholipid syndrome

Follow-up Brucellacapt and Rose Bengal Tests in 110 Children with Brucellosis

Abstract Objective The interpretation of serologic tests in brucellosis can be difficult because of nonspecific symptoms and vague signs of disease, and limitations of serological tests to distinguish persistent and cleared infection. Here, we evaluated the role of Brucellacapt test in conjunction with Rose Bengal test (RBT) in the follow-up of children treated for brucellosis. Methods A total of 174 children diagnosed with brucellosis were included in the study. Data about demographic characteristics of patients, clinical and laboratory findings including Brucellacapt and RBT results, therapeutic approach, and response to treatment were collected from medical records. Results Of the 174 cases, 109 (62.6%) were boys and 65 (37.4%) were girls. The mean age of children at the diagnosis was 122 ± 54 months. Sixty-four cases were excluded from the study for loss to follow-up. The follow-up period for the remained 110 cases was 4.3 ± 2.9 months. Eleven cases (10%) had persistent illness, 7 (6.4%) had recurrence/relapse, and 92 had favorable outcome. During the follow-up, Brucellacapt titers did not drop under 1/320 in cases with persistent illness, and it increased again to 1/320 in cases with relapses at average 6.1 months after treatment. In 48 of cases with favorable outcome, Brucellacapt titers decreased to 1/160 in average 3.3 ± 1.8 months; in 35 cases, RBT became negative in average 3.8 ± 2.5 months, and there was no statistically significant difference between them (p = 0.241). In cases with higher Brucellacapt titers on admission, decrement of titers took longer time. Conclusion Persistent serological titers without clinical findings of brucellosis should not lead physician to prolong or repeat treatment because the decline in Brucellacapt titers and RBT negativity may be delayed in contrast to clinical recovery.

Outcomes From Re-Treatment and Cerebrospinal Fluid Analyses in Patients With Syphilis Who Had Serological Nonresponse or Lack of Seroreversion After Initial Therapy.

We conducted an observational study to determine whether patients with syphilis who do not demonstrate serological cure or lack of seroreversion in nontreponemal (NT) antibody titers after initial therapy benefit from re-treatment and cerebrospinal fluid (CSF) analysis. We enrolled patients with syphilis from sexually transmitted disease clinics in Guangzhou, China, who had persistent NT titers after therapy. Serological nonresponse was defined as a <4-fold decline in baseline NT titers after therapy. Lack of seroreversion was defined as demonstrating a ≥4-fold NT titer decline but without seroreversion to negative, or having persistent low-level titers (i.e., 1:1-1:2) after therapy. After consent, we abstracted medical record data regarding syphilis diagnoses, initial and re-treatment regimens, and serological outcomes. Nontreponemal titers were obtained from participants at enrollment and follow-up. We evaluated CSF findings among a subgroup of participants relative to re-treatment. From March 2012 to February 2016, we enrolled 135 HIV-negative patients with syphilis with persistent NT titers after initial therapy. Among 116 participants with ≥12 months of follow-up, 60 (52%) received re-treatment of syphilis. Overall, there were no significant differences in serological response between those who were re-treated and those who were not among serological nonresponders (29% vs. 27%; P = 1.0) or among participants without seroconversion (41% vs. 37%; P = 0.8). Of 60 participants who underwent CSF analyses, 8 (13%) had CSF abnormalities, but only 2 (3%) met the neurosyphilis criteria after re-treatment. Most HIV-negative patients with syphilis who have serological nonresponse or lack of seroreversion after therapy do not benefit from re-treatment in the short term, and neurosyphilis is uncommon.

Phylogenetic and Timescale Analysis of Barmah Forest Virus as Inferred from Genome Sequence Analysis.

Barmah Forest virus (BFV) is a medically important mosquito-borne alphavirus endemic to Australia. Symptomatic disease can be a major cause of morbidity, associated with fever, rash, and debilitating arthralgia. BFV disease is similar to that caused by Ross River virus (RRV), the other major Australian alphavirus. Currently, just four BFV whole-genome sequences are available with no genome-scale phylogeny in existence to robustly characterise genetic diversity. Thirty novel genome sequences were derived for this study, for a final 34-taxon dataset sampled over a 44 year period. Three distinct BFV genotypes were characterised (G1–3) that have circulated in Australia and Papua New Guinea (PNG). Evidence of spatio-temporal co-circulation of G2 and G3 within regions of Australia was noted, including in the South West region of Western Australia (WA) during the first reported disease outbreaks in the state’s history. Compared with RRV, the BFV population appeared more stable with less frequent emergence of novel lineages. Preliminary in vitro assessment of RRV and BFV replication kinetics found that RRV replicates at a significantly faster rate and to a higher, more persistent titre compared with BFV, perhaps indicating mosquitoes may be infectious with RRV for longer than with BFV. This investigation resolved a greater diversity of BFV, and a greater understanding of the evolutionary dynamics and history was attained.

EP05 The wolf finds unusual prey

Abstract Background Systemic lupus erythematosus (SLE) or lupus (Latin for wolf) is a rare multi-system autoimmune disease that has usually presented by the fifth decade, with a seven-fold higher incidence in females, especially of Afro-Caribbean descent. It is a recognised cause of pyrexia of unknown origin (PUO) though infection and malignancy are far commoner causes. Lupus nephritis (LN) can be life-threatening and affects nearly one-third of patients. We highlight a surprising case of late-onset SLE in a 65-year-old Caucasian man that presented with PUO and early LN. Methods Our patient was known to have atrial fibrillation, hypertension and previous obstructing renal calculus and presented to the Emergency Department with two weeks of right flank pain and fevers. He required critical care admission due to haemodynamic instability. CT excluded obstructive uropathy but a complex right renal cyst was present with mild inflammatory stranding. Bloods showed new neutrophilia (8.31-9.50 x 109/L), anaemia (haemoglobin 93 g/L), thrombocytopenia (platelets 90 x 109/L) and acute kidney injury (creatinine 128 μmol/l from 90 μmol/l baseline). CRP persisted above 110 mg/L. Liver function and ferritin were normal. Despite escalation of antibiotics he remained febrile, creatinine peaked at 291 μmol/L with raised urine protein:creatinine ratio (PCR) of 384 mg/mmol. Repeated septic screens and blood-borne virus tests were negative. Further CT showed mild ascites and pleural effusions. Transthoracic echocardiogram revealed a small pericardial effusion only, and pleural aspirate was a transudate, without malignant cells. Results There was clinical improvement after three weeks despite persistent fevers and he was discharged. However, readmission within three days necessitated inotropic support. After stabilisation, he was transferred under Infectious Diseases in a tertiary hospital. Shortly afterwards, the autoimmune screen showed positive anti-nuclear antibody (ANA), with positive Crithidia luciliae IgG double-stranded DNA (dsDNA) and titres &amp;gt;379 IU/mL. Concurrent hypocomplementaemia (C3 0.22 g/L, C4 0.03 g/L) raised the possibility of LN with SLE and renal biopsy demonstrated class 3 LN. Prompt treatment with intravenous glucocorticoids and mycophenylate mofetil (MMF) resulted in an excellent recovery. Almost a year later, he is taking MMF 1g twice daily with prednisolone 10mg daily. His creatinine is stable at 110 μmol/L, urine PCR around 300 mg/mmol and complements have normalised, despite persistent dsDNA titre of 150 IU/mL. He continues driving taxis and reports a good quality of life. Conclusion There was low suspicion of SLE in this case given the absence of typical symptoms and considering his age, gender and ethnicity. A literature review of male patients with SLE suggested tendency for later-onset and a worse prognosis. There appears to be less LN but when present requires prompt immunosuppression as occurred in this case. Currently, the oldest documented male patient with both SLE and biopsy-proven LN at diagnosis was 74 years old. Disclosures M. Chakravorty None. R. Sandler None. A. El-Nayal None.

Safety and immunogenicity evaluation of Brucella abortus S 19 reduced dose vaccine in comparison with Brucella abortus S 19 standard dose vaccine in cattle

Bovine brucellosis, caused by Brucella abortus, is a serious zoonotic disease manifested by reproductive disorders in animals and results in huge economic losses to dairy farmers. This study was undertaken to evaluate the safety and immunogenicity of Brucella abortus S-19 reduced dose vaccine in comparison with Brucella abortus S-19 standard dose vaccine in 4-10 months old female cattle calves by measuring humoral immune responses and cell mediated immune responses. The humoral antibody responses in reduced dose group indicated absence of persistent antibody titres, whereas, those vaccinated withBrucella abortus S-19 standard dose vaccine showed persistence in antibody titres till day 240 with i-ELISA and day 150 with c-ELISA post vaccination. The IFN-γ responses in vaccinated groups were found to be diminishing till 3 years post vaccination. It is concluded that Brucella abortus S-19 reduced dose vaccine performed similar to that of Brucella abortus S-19 standard dose vaccine.

Immunogenicity of imported foot-and-mouth vaccines in different species in Mongolia

Foot-and-mouth disease (FMD) is a high impact viral disease of livestock for which vaccines are extensively used in control. Mongolia has regular incursions of FMD virus that are typically limited to the eastern region although large epidemics are occasionally reported in the normally disease-free western areas. Vaccines are imported and form an important component of the control strategy. In 2015, post-vaccination monitoring guidelines were published by the FAO-OIE recommending approaches for assessing the appropriateness of imported vaccines including small-scale immunogenicity studies. This study used these recommended approaches to guide the use of vaccine adjuvant type and the need for a one or two dose primary course in the national control programme considering cattle, sheep and Bactrian camels and also whether these vaccines were appropriate for the FMD virus lineages considered high risk to Mongolia (A/ASIA/Sea-97; O/SEA/Mya-98; O/ME-SA/PanAsia; O/ME-SA/Ind-2001). The results of these immunogenicity studies indicated that in cattle and sheep, oil-adjuvanted vaccines led to higher and more persistent neutralisation titres that were satisfactory against the target lineages if a two-dose primary course was utilised. In contrast, aqueous-adjuvanted vaccines were associated with lower titres that likely required a booster after 3 months. Levels of antibodies in Bactrian camels were significantly lower although it is unknown how these may correlate with protection under experimental or field exposure conditions. The results of this study have implications for vaccine policy in Mongolia and suggest further studies on the role of Bactrian camels in the epidemiology of FMD are necessary to indicate if further research on FMD vaccines are needed in this species.

Placental site trophoblastic tumor as a rare cause of irregular bleeding in a female of reproductive age

Objective: A case of placental site trophoblastic tumor (PSTT) that presented with abnormal vaginal bleeding is reported because of its rarity. Case report: The patient presented with 8 weeks of amenorrhea, vaginal bleeding and a persistently low titer of β-human chorionic gonadotropin (βhCG). A large circumscribed mass in the uterus was revealed by ultrasound and magnetic resonance imaging. Hysteroscopic biopsy confirmed the presence of PSTT and a hysterectomy was subsequently performed. The patient is well after 6 months of follow up and her βhCG titer normalized. Conclusion: Rare forms of trophoblastic disease should be considered in the differential diagnosis of persistent bleeding and low titers of βhCG.

Interim Analysis of the Extension Study with rVIII-SingleChain in Previously Untreated Patients (PUPs) with Severe Hemophilia A (CSL627-3001)

Interim Analysis of the Extension Study with rVIII-SingleChain in Previously Untreated Patients (PUPs) with Severe Hemophilia A (CSL627-3001)

Propagations of grouper (Epinephelus sp.) viruses in a new fibroblast-like cell line from orange spotted grouper (E. coioides) brain

Viral nervous necrosis virus (VNNV) and both ranavirus-type and megalocytivirus-type grouper iridoviruses (GIV-R and GIV-M, respectively) are three main viral causative agents in grouper industry. Although many grouper cell lines have been developed, very few studies showed that these three grouper viruses could proliferate well in the same host cellular system. In this study, propagations of grouper original VNNV, GIV-R and GIV-M were carried out in a newly established grouper brain (GB11) cell line. The result showed that both GNNV and GIV-R could propagate efficiently in GB11 cells, whereas GIV-M could maintain persistently moderate propagations, which were evidenced strongly by cytopathic effect (CPE) observation, transmission electron micrographs analysis and persistent viral titer measurements. Western-blotting analysis showed that polyclonal antibodies against GNNV capsid protein and GIV-R major capsid protein, and a mouse monoclonal antibody against GIV-M could strongly recognize the corresponding infected GB11 cells with GNNV, GIV-R and GIV-M, respectively, which also supported that three grouper viruses could replicate well in GB11 cells. Artificial infection showed that GB11-cultured GNNV, GIV-R and GIM-M resulted in 73.3%, 93.3% and 100% cumulative mortalities (n = 30) in the same juvenile hybrid grouper (E. fuscoguttatus × E. lanceolatus) infection model, respectively. Moreover, the highly lethal infection of GB11-cultured GIV-M was confirmed furtherly by histopathology and immunohistochemistry analysis. Collectively, our study provides robust experimental evidences that GB11 is a potential cellular material suitable for the study of grouper original VNNV, GIV-R as well as GIV-M.