Serological Patterns Research Articles

Clinical and laboratory characteristics in juvenile-onset systemic lupus erythematosus across age groups.

BackgroundSystemic lupus erythematous (SLE) is a systemic autoimmune/inflammatory condition. Approximately 15–20% of patients develop symptoms before their 18th birthday and are diagnosed with juvenile-onset SLE (JSLE). Gender distribution, clinical presentation, disease courses and outcomes vary significantly between JSLE patients and individuals with adult-onset SLE. This study aimed to identify age-specific clinical and/or serological patterns in JSLE patients enrolled to the UK JSLE Cohort Study.MethodsPatient records were accessed and grouped based on age at disease-onset: pre-pubertal (≤7 years), peri-pubertal (8–13 years) and adolescent (14–18 years). The presence of American College of Rheumatology (ACR) classification criteria, laboratory results, disease activity [British Isles Lupus Assessment Group (BILAG) and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K) scores] and damage [Systemic Lupus International Collaborating Clinics (SLICC) damage index] were evaluated at diagnosis and last follow up.ResultsA total of 418 JSLE patients were included in this study: 43 (10.3%) with pre-pubertal disease onset; 240 (57.4%) with peri-pubertal onset and 135 (32.3%) were diagnosed during adolescence. At diagnosis, adolescent JSLE patients presented with a higher number of ACR criteria when compared with pre-pubertal and peri-pubertal patients [pBILAG2004 scores: 9(4–20] vs. 7(3–13] vs. 7(3–14], respectively, p = 0.015] with increased activity in the following BILAG domains: mucocutaneous (p = 0.025), musculoskeletal (p = 0.029), renal (p = 0.027) and cardiorespiratory (p = 0.001). Furthermore, adolescent JSLE patients were more frequently ANA-positive (p = 0.034) and exhibited higher anti-dsDNA titres (p = 0.001). Pre-pubertal individuals less frequently presented with leukopenia (p = 0.002), thrombocytopenia (p = 0.004) or low complement (p = 0.002) when compared with other age groups. No differences were identified in disease activity (pBILAG2004 score), damage (SLICC damage index) and the number of ACR criteria fulfilled at last follow up.ConclusionsDisease presentations and laboratory findings vary significantly between age groups within a national cohort of JSLE patients. Patients diagnosed during adolescence exhibit greater disease activity and “classic” autoantibody, immune cell and complement patterns when compared with younger patients. This supports the hypothesis that pathomechanisms may vary between patient age groups.

Fever in the returned traveller: the utility of the Platelia Dengue NS1 antigen enzyme immunoassay for the diagnosis of dengue in a non-endemic setting

Investigating fever in the returned traveller can be difficult and costly. Dengue is one of the most frequently reported aetiologies. NS1 is a non-structural dengue virus protein detectable during acute infection. The aim of this report is to describe the utility of the Platelia Dengue NS1 antigen enzyme immunoassay (EIA) for detection of dengue in a non-endemic region compared to a composite gold standard of contemporaneous molecular testing and seroconversion. We performed a retrospective analysis of all dengue serology tests from 6 February 2012 to 5 December 2018. Dengue serology and in-house flavivirus molecular results were identified using the laboratory information management system. Dengue serology was performed using the Bio-Rad Platelia Dengue NS1 antigen EIA, and Abbott Panbio Dengue IgG and IgM EIA. True positive NS1 result was defined as positive molecular test within one week of the positive NS1 result or seroconversion within 120 days. NS1 negative samples that remained negative to all dengue markers on repeat more than 10 and up to 120 days after were labelled as true negatives. More than 75% of cases had a serology pattern consistent with primary dengue. Sensitivity and specificity of NS1 Ag EIA was 96.4% (95% CI 92.3-98.7%) and 98.4% (95% CI 94.5-99.8%), respectively. Performance was poorer in serotype 4 infections (sensitivity 50%). Platelia Dengue NS1 antigen EIA test performance in the returned traveller cohort fulfils the remit as a single diagnostic test for acute dengue infection.

Circulating Antibodies against Epstein-Barr Virus (EBV) and p53 in EBV-Positive and -Negative Gastric Cancer.

Epstein-Barr virus (EBV)-positive gastric cancers have clinicopathologic differences from EBV-negative tumors and lack TP53 mutation. Serologic profiles may inform viral contribution to carcinogenesis. We compared humoral responses of EBV-positive (n = 67) and EBV-negative (n = 137) patients with gastric cancer from the International EBV-Gastric Cancer Consortium. Serum antibodies against four EBV proteins, nuclear (EBNA), viral capsid (VCA), early-diffuse (EA-D), and Zta replication activator (ZEBRA), and to p53 were assessed by multiplex assays. OR of antibody level tertiles (T1-T3) were adjusted by logistic regression. We also conducted a meta-analysis of reported anti-p53 seropositivity in gastric cancer. Consistent with EBV's ubiquity, 99% of patients were seropositive for anti-EBNA and 98% for anti-VCA, without difference by tumor EBV status. Seropositivity varied between patients with EBV-positive and EBV-negative tumors for anti-EA-D (97% vs. 67%, respectively, P < 0.001) and anti-ZEBRA (97% vs. 85%, respectively, P = 0.009). Adjusted ORs (vs. T1) for patients with EBV-positive versus EBV-negative tumors were significantly elevated for higher antibodies against EBNA (2.6 for T2 and 13 for T3), VCA (1.8 for T2 and 2.4 for T3), EA-D (6.0 for T2 and 44 for T3), and ZEBRA (4.6 for T2 and 12 for T3). Antibodies to p53 were inversely associated with EBV positivity (3% vs. 15%; adjusted OR = 0.16, P = 0.021). Anti-p53 prevalence from the literature was 15%. These serologic patterns suggest viral reactivation in EBV-positive cancers and identify variation of p53 seropositivity by subtype. Anti-EBV and anti-p53 antibodies are differentially associated with tumor EBV positivity. Serology may identify EBV-positive gastric cancer for targeted therapies.

Isolated Anti-HBc: Significance and Management.

Hepatitis B virus (HBV) infection is prevalent worldwide and is associated with dramatic levels of morbidity and mortality. Isolated anti-HBc (IAHBc) is a particular serological pattern that is commonly found in immunocompromised patients. There is ongoing debate regarding the management of patients with IAHBc. Herein, we summarize the current guidelines and the newest evidence. The frequency of IAHBc is variable, with a higher prevalence in some populations, such as persons living with HIV and others immunocompromised patients. The risk of HBV reactivation depends on host factors (including immunosuppression) and viral factors. It is now well established that immunocompromised patients can be classified into three groups for risk according to the type of immunosuppression and/or treatment. In patients at high risk, HBV therapy has to be considered systematically. In patients at moderate risk, the decision is based on the level of HBV DNA (preemptive treatment or monitoring and vaccination). In patients with low risk, HBV vaccination is another possible approach, although further studies are needed to assess the type of preemptive strategy.

Patterns of hepatitis B virus exposure and associated predictors in Vietnam: A crosssectional study

Objective: To examine the magnitude of isolated anti-HBc and other HBV serological patterns and associated predictors among adults seeking general health check-up at a large health center in Vietnam.Methods: All 564 outpatients seeking general health checkup between January 2016 and December 2016 were asked to undertake HBV surface antigen, surface antibody, IgG and IgM core antibody (anti-HBc total), platelet counts, and liver function testing. An administered questionnaire was used to collect information regarding demography, in-house sources of infection, lifestyle, health condition and treatment, and HBV vaccination. Results: Male gender (P=0.043), age (P=0.000), living in urban areas (P=0.040), HBV vaccination status (P=0.033), and ALT (P=0.040) were associated with isolated anti-HBc. HBV infection was associated with HBV vaccination status (P=0.001), ALT levels (P=0.010), AST levels (P=0.020), and platelet counts (P=0.007). Past/resolved HBV infection was associated with AST levels (P=0.005), ALT levels (P=0.014), and age (P=0.000). Conclusions: Isolated anti-HBc is quite prevalent. Predictors of isolated anti-HBc include male gender, living in rural areas, and HBV non-vaccination. The prevalence of isolated anti-HBc also increases with age. To timely detect occult HBV infection and prevent transmission, anti-HBc testing should be included in the health check-up for high risk individuals and screening program where HBV nucleic acid test is not available. To prevent transmission, clinicians need to pay more attention on those who are at risk of having isolated anti-HBc and closely follow-up patients with isolated anti-HBc and educate them about the prevention of HBV infection.

Clinical characteristics and association analysis of persistent low-level HBsAg expression in a physical examination population with HBV infection.

Certain patients with hepatitis B virus (HBV) infection present with persistently low levels of serum hepatitis B surface antigen (HBsAg) and have been indicated to have low rates of HBV nucleic acid replication. To explore the serological and molecular epidemiological characteristics of HBV population with low-level HBsAg in the present study, associated serum markers and virologic genotype detection were performed accordingly. Determination of HBV markers was performed using a chemiluminescence immunoassay from which 2,544 out of 45,256 adults who underwent routine health examination were tested positive for HBsAg. HBV DNA was detected by real-time fluorescent quantitative PCR. The patients were divided into low-level and high-level groups, according to their HBsAg levels (cut-off value, 10 IU/ml). The prevalence and levels of HBsAg positivity and HBV DNA in patients with HBV infection were analyzed by age, sex, serological pattern and clinical type. The fibrosis status of patients with low-level HBsAg was assessed by determining the aspartate aminotransferase-to-platelet ratio (APRI), and sequencing was employed to determine serotypes and genotypes. HBV-infected patients with low-level HBsAg (<10 IU/ml) accounted for 15.41% of the 2,544 HBsAg-positive patients, and the prevalence of HBsAg positivity exhibited a tendency to increase with age. The male-to-female ratio was ~1.9:1, and the average age was 54.98±16.28 years among HBV-infected patients with low-level HBsAg. The major serological pattern and clinical types were HBsAg/antibody against hepatitis Be antigen (anti-HBe)/antibody against hepatitis B core antigen (anti-HBc)-positive (94.90%) and chronic asymptomatic (ASC) (97.95%), respectively. HBV DNA exhibited a low-level of replication and the prevalence of HBV DNA positivity assessed by the routine method and by the enrichment method was 27.74% (97/392) and 45.92% (180/392), respectively. No significant differences among the age groups were identified in the different HBsAg level groups (P>0.05). The prevalence of HBV DNA positivity was associated with HBsAg only in patients with serological pattern HBV-M2 (HBsAg/anti-HBe/anti-HBc-positive) in the low-level HBsAg group (odds ratio: 1.30; 95% CI: 1.15–1.47; P<0.05). The APRI had no association with age, HBsAg, HBV DNA level or liver function index in ASC patients in the low-level HBsAg group (P>0.05). The prevalence of the serotype adw and genotype B was 85.53 and 89.47%, respectively. Further improvement in the systematic study of populations with low-level HBsAg has important clinical and epidemiological significance for improving the detection of HBV serological markers, elucidating the mechanisms leading to low-level HBsAg, overcoming immune tolerance to eliminate HBV infection and preventing HBV transmission.

846. Postnatally Acquired Zika Virus (ZIKV) Infection in Infants and Young Children in Guatemala: Serologic and Neurodevelopmental (ND) Evaluation

BackgroundDiagnosing ZIKV infection in children in dengue (DENV) endemic regions is challenging. The kinetics and effects of maternal Ab on infant infection responses remain unknown, as do the ND effects of ZIKV acquired in early life.MethodsThis is a population-based prospective cohort study in infant–mother pairs and children <5 years in a rural DENV endemic area of Guatemala evaluating the incidence and ND outcomes of postnatally cquired ZIKV infection. Subjects were followed 1 year for symptoms of flavivirus-like illness (FLI), serologic and virologic evidence of ZIKV or DENV infection and ND outcomes. ZIKV and DENV neutralizing antibodies (NAb) were measured at enrollment and longitudinally. Subjects were classified as ZIKV- or DENV-infected based on NAb. Specimens from acute illnesses were tested for viral RNA by rRT-PCR. ND was assessed at enrollment and longitudinally using an adapted Mullen Scales of Early Learning (MSEL).ResultsIn total, 1,371 subjects (374 children 1–5 years, 500 infants, 497 mothers) were enrolled from June 2017 to July 2018. Among 1,335 evaluable subjects, 7.6% (101) had serologic evidence of recent ZIKV infection (NAb >500 or >100 and DENV-neg); 13.2% (176) were DENV-pos only; 44.8% (598) were ZIKV-neg (NAb15 −<100) or low (<500) ZIKV and DENV NAb, suggesting prior flavivirus infection or cross-reactivity (Figures 1 and 2). ZIKV infection alone was more prevalent in children 1–5 years, while infants’ serologic pattern was similar to that of their mothers. One child ZIKV seroconverted. In 391 FLI episodes (67 children 1–5 years and 215 infants with fever, rash, myalgia, and conjunctivitis; 109 mothers with fever, myalgia, and joint pain), acute DENV infections, but not ZIKV, were identified by rRT-PCR. MSEL scores were similar to US norms in infants <12 m (composite mean 94.8, SD 11.9), but lower in children 1–5 years in all domains (mean 75.1, SD 17.4, P < 0.0001) (Figure 3).ConclusionSerologic evidence of recent ZIKV infection, but no acute ZIKV, was documented in young children in Guatemala. Infant seroreactivity derives from prior maternal infection and DENV cross-reactivity. Observed substantial differences in ND scores between infants and children 1–5 years challenge the ability to isolate the potential effects of ZIKV infection in early life. NIAID Contract HHSN272201300015I Task Order HHSN27200013. FMM and EJA Co-PIs. DisclosuresFlor M. Munoz, MD, Biocryst: Grant/Research Support; CDC: Research Grant; Moderna: Other Financial or Material Support, Safety Monitoring Board Member/Chair; NIH: Research Grant; Novavax: Research Grant; UP to Date: Author and Editor: Royalties, Other Financial or Material Support.

2311 Syphilis Hepatitis Presenting as a Mimic of Primary Biliary Cholangitis

INTRODUCTION: Primary Biliary Cholangitis (PBC) is a progressive cholestatic liver disease defined by autoimmune destruction of intrahepatic bile ducts. Patients typically present with a cholestatic liver injury pattern. Anti-mitochondrial antibody (AMA) is present in 95% of PBC diagnoses thus, an AMA titer of 1:40 in addition to alkaline phosphatase (ALP) greater than 1.5 times the upper limit of normal is diagnostic of PBC (1). Syphilis is a sexually transmitted infectious disease caused by transmission of Treponema pallidum. The highest risk populations are men who have sex with men (MSM) and persons living with HIV. Syphilis has been further associated with HIV infection considering shared risk factors and transmission routes. While the staged progression of syphilis is well-documented, not all presentations are readily observed by clinicians considering the variability of the disease. One variation that is sparingly seen is syphilis presenting as acute hepatitis. CASE DESCRIPTION/METHODS: A 54 year-old man living with HIV presented to University of Kentucky Hospital with one week of abdominal pain, vomiting, and a diffuse non-pruritic rash. Upon admission he was noted to have a cholestatic liver injury pattern. Laboratory evaluation revealed AST 91, ALT 120, ALP 832, total bilirubin 6.4, and CD4 count 336. The acute hepatitis panel was negative. Abdominal CT and ultrasound failed to demonstrate biliary ductal dilation. Further investigation revealed an RPR titer 1:256 and an anti-mitochondrial M2 antibody IgG of 83.5U. The patient was treated for syphilis with doxycycline due an allergy to penicillin. Subsequently there was complete resolution of the cholestatic liver injury and a final diagnosis of syphilis hepatitis. DISCUSSION: In this report, we present a case of syphilis that presented similar to PBC with a consistent serologic pattern and a positive AMA. Other reports have recognized syphilis as a reversible cause of cholestatic liver injury. One study in particular, recognized a high false positive AMA rate in patients with syphilis (2). As, syphilis is a easily targeted cause of liver injury, we suggest testing high-risk patients with a presumed diagnosis of PBC.

Clinical Practice Guidance for Management of Anti HBc Positive Patients

Hepatitis B core antibody (Anti HBc) is currently considered the most sensitive serological marker for a patient’s history of hepatitis B virus (HBV) infection given its long-term persistence in the bloodstream. The serological pattern of isolated Anti HBc (IAHBc) has been of clinical interest over the past several years.,Thegrowing data of IAHBcsuggestingit as a marker for occult HBV infection (OBI). Occult HBV infection defined as HBV DNA detection in serum or the liver by sensitive diagnostic tests in HBsAg negative individuals with or without serologic markers of previous viral exposure. OBI is especially concerned in blood transfusion (BT), organ donation and reactivation of HBV infection following immunosuppressive therapy. HBV reactivation depends on viral and host factors. The important clinical implications of IAHBcis in the setting of co-infection with hepatitis C virus (HCV), reactivation risk of HBV during directly acting anti viral (DAA) therapy in HCV infection which may lead to progression of liver disease and hepatocellular carcinoma (HCC). Antiviral prophylaxis has been recommended in moderate to high risk of reactivation prior to immunosuppressive and biologics. The main goal of therapy is to improve survival and quality of life by preventing disease progression and to prevent consequent development of HCC. It is proposed to perform Anti-HBc test as a screening test prior to blood transfusion, HBVvaccination, DAA and immunosuppressive therapy in addition to HBsAg screening test.&#x0D; J Bangladesh Coll Phys Surg 2019; 37(4): 196-201

Coexistence of low levels of HBsAg and high levels of anti-HBs may increase risk of hepatocellular carcinoma in chronic hepatitis B patients with high HBV load

ObjectiveThe clinical significance of coexistence of HBsAg/anti-HBs in chronic hepatitis B (CHB) patients remains controversial. This study was aimed to assess the association of this serological pattern with hepatocellular carcinoma (HCC) in patients with CHB. MethodsIn this cross-section study, 206 CHB patients with coexistence of HBsAg/anti-HBs and 206 CHB patients with HBsAg alone were included to evaluate the risk of HCC development by logistic regression analysis. In addition, a retrospective cohort of 260 patients with CHB was recruited to estimate the cumulative incidence of HCC by Kaplan–Meier analysis. ResultsThe serological pattern of coexistence of HBsAg/anti-HBs, with high levels of (“High”) HBsAg/low levels of (“Low”) anti-HBs, were considered as independent risk factors for HCC. In particular, patients with “High” HBsAg/“High” anti-HBs [odds ratio (OR), 4.295; 95% confidence interval (CI), 1.104–16.699; p = 0.035] and “Low” HBsAg/ “High” anti-HBs (OR, 3.207; 95%CI, 1.299–7.919; p = 0.012) exhibited significantly higher risk for HCC development. However, only “Low” HBsAg /“High” anti-HBs might increase risk of HCC in CHB patients with high HBV load (logrank p < 0.001) in our cohort study. ConclusionThe coexistence of “Low” HBsAg /“High” anti-HBs might increase the risk of HCC development in CHB patients with high HBV load, which reflected that the long-term interaction between immune response and virus might lead to the development of HCC. The identification of the patients with poor prognosis will help clinicians to refine the therapeutic decisions and individualize follow-up strategies.

Longitudinal study of Mycobacterium avium ssp. paratuberculosis fecal shedding patterns and concurrent serological patterns in naturally infected dairy cattle

Mycobacterium avium ssp. paratuberculosis (MAP) is the etiological agent of paratuberculosis, a disease that affects ruminants worldwide. Despite global interest in the control of this disease, gaps exist in our knowledge of fecal shedding patterns and concurrent serological patterns. This longitudinal study in dairy cattle herds with high MAP seroprevalence in France aimed at accurately describing fecal shedding patterns over 1 year; relating those shedding patterns to individual animal characteristics (age, breed, parity); and exploring the association between fecal shedding patterns and serological patterns. To describe temporal fecal shedding patterns and continuity of shedding, along with the standard quantitative PCR (qPCR) threshold cycle we used a cutoff value that related to low or nonculturable fecal shedding. We also defined a threshold cycle indicative of shedding in high quantities to describe infection progression patterns. Twenty-one herds completed the study, and 782 cows were tested 4 times each. We obtained 4 sets of paired fecal qPCR and serum ELISA results from 757 cows. Although we targeted highly likely infectious animals, we found a large diversity of shedding patterns, as well as high variability between herds in the proportion of animals showing a given pattern. The fecal qPCR results of almost 20% of the final study sample were positioned at least once in the range that indicated low or nonculturable fecal shedding (between the adjusted and the standard cutoff value). Although these animals would typically be classified as non-shedders, they could be important to infection dynamics on the farm. Animals that shed at least twice consecutively and animals that shed in high quantities rarely reverted to negativity. Repeated fecal qPCR can be used to detect temporal fecal shedding traits, and the decision to cull an animal could practically be based on temporal, semiquantitative results. Overall, we found a mismatch between fecal shedding and ELISA seropositivity (637 animals were ELISA-negative 4 times, but only 13% of those animals were qPCR-negative 4 times). We found that having more than 2 ELISA-positive samples was strongly related to persistent and continuous shedding. We suggest that although serological testing is much less sensitive than qPCR, it can also be used, particularly over the course of multiple testing events, to identify animals that are most likely to contribute to the contamination of the farm environment.

Whole exome sequencing and pedigree analysis for a case with an ABw03 subtype

To explore the molecular basis for a blood donor with an ABO subtype. The proband and his family members were subjected to serological analysis. Their genotypes were determined by real-time PCR and sequencing of the coding regions of ABO gene. The proband was determined as an ABw subtype. By sequencing analysis, the proband was typed as A102/BW03. Compared with ABO*B.01, the proband was found to harbor a 721C>T variant (ABO*BW.03 allele) in exon 7 of the ABO gene, which caused substitution of Arginine at position 241 by Tryptophan resulting in a ABW phenotype. The blood type of the proband's sister was similar to that of the proband. The maternal serological pattern was B type, and the result of sequencing suggested that the genotype fit with B101/Bw03. The 721C>T in the exon 7 of the ABO glycosyltransferase gene probably underlies the Bw03 phenotype. The ABO*Bw.03 variant of the proband and his sister were inherited from their mother.

PS1114 PATIENTS WITH GAUCHER DISEASE SHOW AN IMMUNE‐DYSREGULATION PATTERN SECONDARY TO A DEFECT OF APOPTOSIS

Background:Gaucher Disease (GD) is a congenital disorder secondary to GBA1 gene mutations that cause a defective function of the catabolic enzyme β‐glucocerebrosidase (GBA) and a progressive accumulation of its substrate‐ glucocerebroside (GC) in various organs, in particular in mononuclear phagocite system. Bone infiltration, hepatosplenomegaly and cytopenia represent the most common features of the disease. Since clinical manifestation can be subdolous, in some cases, phenotype can overlap with Autoimmune Lymphoproliferative Sindrome (ALPS). Nonetheless, GD patients were also shown to have hyperinflammatory features‐ secondary to machrophages engorgement and actviation‐ and an aspecific impaiment involving B, T and NK cells. In addition, some patients also showed more specific ALPS‐like immune‐dyregulation features suggesting an underlying apoptosis defect.Aims:To evaluate specific ALPS‐like immunological and serological pattern (Double Negative T‐cells, TCR alfa/beta B220, B‐memory cells, T‐regs/HLA‐DR ratio, IL‐10, IL‐18,) in a cohort patients with GD and to test apoptosis pathway function in those showing ALPS‐like features.Methods:All patients were diagnosed with GD by enzyme assay on lymphocytes culture or fibroblasts and by characterization of pathogenetic variants of GBA1. Lymphocytes subsets and ALPS‐related serum biomarkers (IL‐10, IL‐18, sFAS, Vit.B12) were analyzed in 41 GD patients followed‐up at Istituto Giannina Gaslini. Furthermore, in those patients who showed an ALPS‐like phenotype, apoptosis function was analyzed after FAS–induced stimulation of EBV‐immortalized B‐cells and Western blot analysis of CASP10, CASP8, and PARP proteins.Results:10/41 (24%) patients showed an ALPS‐like immunological pattern which was more frequent in naïve patients (p = 0.003) and in patients with an earlier onset of the diesease (p = 0.010). EBV‐immortalized B‐cells of 7 out of these 10 patients were further studied and all of them showed a defective FAS‐induced apoptosis and caspases activation. Fig 1 shows apoptosis evalutation of the selected population.Summary/Conclusion:To the best of our knowledge, this study shows for the first time that untreated subjects with early‐onset GD present an immune‐dysregulation pattern secondary to a defect of apoptosis as seen in ALPS patients. These results suggest that diagnostic work‐up of both diseases must take into consideration their clinical and biochemical overlap. Further studies are needed to evaluate the potential role of cell‐membrane lipids impairment on FAS receptor structure as a cause of such defect.image

PS1115 THE RELATIONSHIP BETWEEN THE PRETREATMENT PNH CLONE SIZE AND CLINICAL COURSE IN PATIENTS WITH BONE MARROW FAILURE SYNDROMES: INTERIM ANALYSIS OF JAPANESE MULTICENTER PROSPECTIVE STUDY

Background: Gaucher Disease (GD) is a congenital disorder secondary to GBA1 gene mutations that cause a defective function of the catabolic enzyme β-glucocerebrosidase (GBA) and a progressive accumulation of its substrate- glucocerebroside (GC) in various organs, in particular in mononuclear phagocite system. Bone infiltration, hepatosplenomegaly and cytopenia represent the most common features of the disease. Since clinical manifestation can be subdolous, in some cases, phenotype can overlap with Autoimmune Lymphoproliferative Sindrome (ALPS). Nonetheless, GD patients were also shown to have hyperinflammatory features- secondary to machrophages engorgement and actviation- and an aspecific impaiment involving B, T and NK cells. In addition, some patients also showed more specific ALPS-like immune-dyregulation features suggesting an underlying apoptosis defect. Aims: To evaluate specific ALPS-like immunological and serological pattern (Double Negative T-cells, TCR alfa/beta B220, B-memory cells, T-regs/HLA-DR ratio, IL-10, IL-18,) in a cohort patients with GD and to test apoptosis pathway function in those showing ALPS-like features. Methods: All patients were diagnosed with GD by enzyme assay on lymphocytes culture or fibroblasts and by characterization of pathogenetic variants of GBA1. Lymphocytes subsets and ALPS-related serum biomarkers (IL-10, IL-18, sFAS, Vit.B12) were analyzed in 41 GD patients followed-up at Istituto Giannina Gaslini. Furthermore, in those patients who showed an ALPS-like phenotype, apoptosis function was analyzed after FAS–induced stimulation of EBV-immortalized B-cells and Western blot analysis of CASP10, CASP8, and PARP proteins. Results: 10/41 (24%) patients showed an ALPS-like immunological pattern which was more frequent in naïve patients (p = 0.003) and in patients with an earlier onset of the diesease (p = 0.010). EBV-immortalized B-cells of 7 out of these 10 patients were further studied and all of them showed a defective FAS-induced apoptosis and caspases activation. Fig 1 shows apoptosis evalutation of the selected population.Summary/Conclusion: To the best of our knowledge, this study shows for the first time that untreated subjects with early-onset GD present an immune-dysregulation pattern secondary to a defect of apoptosis as seen in ALPS patients. These results suggest that diagnostic work-up of both diseases must take into consideration their clinical and biochemical overlap. Further studies are needed to evaluate the potential role of cell-membrane lipids impairment on FAS receptor structure as a cause of such defect.

Serological evidence of Leishmania infection by employing ELISA and rapid tests in captive felids and canids in Brazil.

Visceral leishmaniasis (VL) is a zoonosis and the dog is considered the most important urban reservoir. Cases in cats have been reported, but little is known about Leishmania infection and disease in wild felids and canids kept in captivity in endemic areas. Thus, the serological pattern of wild felids and canids kept in captivity at the Belo Horizonte Zoological Garden was investigated using two primary antigens for conventional ELISA: k39 and rKDDR, as well as three serological rapid kits: Dual Path Platform (DPP®) immunochromatographic test, rKDDR Immunochromatographic assay and ELISA SNAP Leishmania IDEXX®. A total of 21 serum samples, 13 of wild felids and 8 wild canids of varying age and sex were evaluated. The results obtained in the tests were analyzed by agreement using Kappa coefficient, and between ELISA antigens all the analysis performed had showed significant agreement among both of them, as well between the three immunochromatographic tests. The results demonstrated that there is serological evidence of wild animals seropositive for Leishmania antibodies at the Belo Horizonte Zoological Garden, and that all the antigens and rapid tests used can be employed in serological screening for VL in wild felids and canids.

Sequence analysis of persistently low level expression of hepatitis B surface antigen S gene in patients with hepatitis B virus infection

Objective To reveal the characteristics of S gene sequence of hepatitis B surface antigen (HBsAg) in hepatitis B virus (HBV)-infected patients with low HBsAg level. Methods From February 2016 to December 2017, 1 308 serum samples of inactive HBsAg carriers were collected from the 903rd Hospital of PLA and Hangzhou Jianggan District People′s Hospital.The cases were divided into high-level group and low-level group according to the level of serum HBsAg (10 IU/mL) expression. The HBV S gene was sequenced in patients with low-level HBsAg expression. In addition, in patients with high-level HBsAg, 100 patients were randomly selected (stratified sampling) for HBV S gene sequencing based on the matching of age and serological pattern (hepatitis B e antigen [HBeAg] negative) of low-level HBsAg group. A comparative analysis was conducted between HBV S gene sequences from inactive HBsAg carrier in low HBsAg expression group and the HBV reference S gene sequences from inactive HBsAg carrier in high HBsAg expression group.The results of normal distribution data were expressed as Mean±SD, and analyzed using t-test. The results of non-normal distribution data were expressed by M(QR), and analyzed using Mann-Whitney U test.Chi-square test or Fisher exact test was used to compare continuous variables and classification variables between the two groups. Results There were 276 serum samples from the low level group and 1 032 serum samples from the high level group, including 257 HBsAg/HBeAg/anti-HBc-positive cases, 753 HBsAg/anti-HBe/anti-HBc-positive cases, and 22 HBsAg/anti-HBc-positive cases. Successful HBV S gene sequencing was performed on 126 out of 276 patients in the low-level HBsAg group. According to the age inthe low-level HBsAg group, 100 samples with negative HBeAg in the high-level HBsAg group were randomly selected, among which 94 patients were genotyped and hemotyped. The results showed that there were statistically significant differences in HBV serological markers, HBV DNA level and HBV genotype distribution between the high level group (94 cases) and the low level group (126 cases) (all P 0.05). For genotype B, 12 single point mutations and 4 dual co-mutations were found in low level group. Among them, one single point mutation (S210R) and 3 dual co-mutations (G44E/V+ T45P/I, G44E/V+ L49P/R and N40S+ I208T) were not hot spot mutations, while 2 dual co-mutations and 2 single point mutations were found in high level group. The difference between two groups was statistical significant (χ2=7.533, P=0.006). For genotype C, 5 single point mutations (T5A, A45T, T47A/K, Q101R and I126S/T) were found in low level group and 1 single point mutation (N3S) in high level group. The difference in mutation frequency between two groups were statistical significant (χ2=47.914, P=0.000). Conclusions Significant mutations in multiple regions and at multiple sites (including co-mutations) on both sides of the MHR may be one of the causes of low HBsAg expression level in this population. Key words: Hepatitis B surface antigens; Genotype; HBV markers; HBV DNA; S gene; Mutation site

Equine Rhinitis A Virus Infection at a Standardbred Training Facility: Incidence, Clinical Signs, and Risk Factors for Clinical Disease.

Respiratory disease is a common morbidity of young racehorses. Infections can lead to compromised welfare, and economic loss. Identification of risk factors for infection through clinical signs monitoring and collection of demographic, serologic, and contact network data can aid in the development of prevention and control strategies. The study objectives were to: (1) describe the transmission and clinical course of infectious respiratory disease in standardbred racehorses in a multi-barn training facility and, (2) identify demographic, serological, and contact network risk factors associated with Equine Rhinitis A virus (ERAV) respiratory disease. The study population included standardbred racehorses (age 1–5 years: n = 96) housed at a multi-barn training facility in southern Ontario. Clinical signs were monitored daily over a 41-day period in fall 2017. Descriptive statistics, including incidence rate, prevalence and incidence risk were calculated for the observed period. Associations between demographic, serologic, and contact pattern variables, and clinical disease status were investigated using multivariable logistic regression. Respiratory disease cases were characterized by mucopurulent discharge (100%), intermittent cough (37.7%), and ocular discharge (62.3%). Fever (>38.5°C) and inappetence were rarely reported (15.2 and 3.8%). Seroconversion to ERAV among cases was 75%. Total, and yearling-specific incidence risks were 52.5 and 87.9%. The cumulative incidence was 0.027 new cases/horse day. A negative association (OR = 0.011) between increasing age and respiratory disease was significant (p = < 0.001) in the final regression model. Yearling horses were at increased risk of infectious respiratory disease as demonstrated by the high yearling-specific incidence risk, and the negative association between age and infection. Disease control strategies, such as vaccination programs and isolation of new horses arriving from auction, should be targeted at young animals entering training facilities.

Defining the structural basis for human alloantibody binding to human leukocyte antigen allele HLA-A*11:01

Our understanding of the conformational and electrostatic determinants that underlie targeting of human leukocyte antigens (HLA) by anti-HLA alloantibodies is principally based upon in silico modelling. Here we provide a biochemical/biophysical and functional characterization of a human monoclonal alloantibody specific for a common HLA type, HLA-A*11:01. We present a 2.4 Å resolution map of the binding interface of this antibody on HLA-A*11:01 and compare the structural determinants with those utilized by T-cell receptor (TCR), killer-cell immunoglobulin-like receptor (KIR) and CD8 on the same molecule. These data provide a mechanistic insight into the paratope−epitope relationship between an alloantibody and its target HLA molecule in a biological context where other immune receptors are concomitantly engaged. This has important implications for our interpretation of serologic binding patterns of anti-HLA antibodies in sensitized individuals and thus, for the biology of human alloresponses.

Sequence ambiguity determined from routine pol sequencing is a reliable tool for real-time surveillance of HIV incidence trends

Identifying individuals recently infected with HIV has been of great significance for close monitoring of HIV epidemic dynamics. Low HIV sequence ambiguity (SA) has been described as a promising marker of recent infection in previous studies. This study explores the utility of SA defined as a proportion of ambiguous nucleotides detected in baseline pol sequences as a tool for routine real-time surveillance of HIV incidence trends at a national level.A total of 353 partial HIV-1 pol sequences obtained from persons diagnosed with HIV infection in Slovenia from 2000 to 2012 were studied, and SA was reported as a percentage of ambiguous base calls. Patients were characterized as recently infected by examining anti-HIV serological patterns and/or using commercial HIV-1 incidence assays (BED and/or LAg-Avidity assay). A mean SA of 0.29%, 0.14%, and 0.19% was observed for infections classified as recent by BED, LAg, or anti-HIV serological results, respectively. Welch's t-test showed a significant difference in the SA of recent versus long-standing infections (p < 0.001). CD4+ T-cell counts ≤250 cells/mm3 significantly correlated with higher SA (p < 0.001), whereas the homo/bisexual transmission route significantly correlated with lower SA (p = 0.005). When the LAg-assay was used as an indicator of recent infection, a receiver operating characteristic curve with the largest area under the curve (0.896) was observed for SA (sensitivity and specificity of 79%), indicating the best correlation of the data. A reliable estimation of the trends of HIV incident infection could be inferred from measuring SA irrespective of the cutoff used; however, in Slovenia it seems that lower cutoffs are more appropriate.Our data suggest that SA could be used as a real-time surveillance tool for close monitoring of HIV incidence trends, especially in countries where baseline HIV resistance genotyping is performed routinely, rendering this approach cost-effective.

Clinical Implications of Concurrent HBsAg/HBsAb Positivity in Patients with Chronic Hepatitis B Infection

AIM: Concurrent positivity for HBsAg and HBs antibody, a phenomenon closely related to HBsAg escape mutants, is an unusual serological pattern in hepatitis B virus (HBV) infection. There is limited information on the clinical course of patients with this serological pattern. Here, we aimed to describe and compare clinical features of patients with chronic HBV infection presented simultaneous HBsAg+/HBsAb+. MATERIAL AND METHODS: This was a retrospective study on 309 patients with chronic HBV. The patients received either tenofovir, lamivudine, or no treatment based on the levels of liver enzymes. Serological profiles were recorded at and after six months of diagnosis. Statistical analysis was performed in SPSS 19. RESULTS: From 309 chronically HBsAg positive patients, 10 (3.2%) showed concurrent positivity for HBsAg and HBsAb in their sera. There were no statistically significant associations between this pattern with either gender, age, and HBeAg status. However, there was a close association between HBsAg+/HBsAb+ status with seropositivity for anti-HBeAg (P=0.05). There were also no significant differences between AST and ALT levels (neither at the diagnosis and nor at the end of six months of diagnosis) between the distinct serological patterns. CONCLUSION: It seems that patients with chronic HBV infection and persistent concurrent reactivity for HBsAg and HBsAb render comparable clinical course with those patients with single HBsAg positivity.