Low Titers Research Articles

Composition of the neutralising antibody response predicts risk of BK virus DNAaemia in recipients of kidney transplants

BK polyomavirus (BKV) DNAaemia occurs in 10% of recipients of kidney transplants, contributing to premature allograft failure. Evidence suggests disease is donor derived. Hypothetically, recipient infection with a different BKV serotype increases risk due to poorer immunological control. Thus, understanding the composition and activity of the humoral anti-BKV responses in donor/recipient (D/R) pairs is critical. Using 224 paired pre-transplant D/R samples, BKV VP1 genotype-specific pseudoviruses were employed to define the breadth of the antibody response against different serotypes (ELISA) and, to characterise specific neutralising activity (nAb) using the 50% inhibitory concentration (LogIC50). Mismatch (MM) ratios were calculated using the ratio of recipient ELISA or nAb reactive BKV serotypes relative to the number of donor reactive serotypes. BKV DNAaemia was observed in 28/224 recipients of kidney transplants. These recipients had lower nAb titres against all the serotypes, with median logIC50 values of 1.19-2.91, compared to non-viraemic recipients' median logIC50 values of 2.13-3.30. nAb D/R MM ratios >0.67 associated with significantly higher risk of BKV viraemia, with an adjusted odds ratio of 5.12 (95% CI 2.07 to 13.04; p<0.001). Notably, a mismatch against donor serotype Ic and II associated with adjusted odds ratios of 8.12 (95% CI 2.10 to 35.61; p=0.002) and 4.52 (95% CI 1.19 to 19.23; p=0.03) respectively. 21 recipients demonstrated broadly neutralising responses against all the serotypes, none of whom developed BKV DNAaemia post-transplant. In contrast, there was poor concordance with PsV-specific ELISA data that quantified the total antibody response against different serotypes. BKV nAb mismatch predicts post-transplant BKV DNAaemia. Specific mismatches in nAb, rather than total seroreactivity, are key indicators of BKV risk post-transplant. This has the potential to risk-stratify individuals and improve clinical outcomes by influencing the frequency of monitoring and individualised tailoring of immunosuppression. Furthermore, detailed examination of individuals with broadly neutralising responses may provide future therapeutic strategies. The research was funded by St. Peters Trust, Royal Free Hospital Charity and Wellcome Trust (grant numbers RFCG1718/05, SPT97 and 204870/Z/WT_/Wellcome Trust/United Kingdom).

Abstract 4136984: Low Occurence of Fetal Extranodal Findings and AV Interval Prolongation in Prospectively Followed High Titer Anti-Ro Pregnancies

. Background: Third-degree atrioventricular block (AVB) is the most common manifestation of Anti-Ro antibody associated fetal cardiac disease. Extranodal findings of isolated cardiac echogenicity, valvulitis with insufficiency and AV interval prolongation have been reported but not described in large prospective series. Aims: To report the occurrence and outcomes of extranodal findings in subjects followed prospectively since 2020 in STOP BLOQ (Surveillance and Treatment to Prevent Fetal AV block Likely to Occur Quickly) and the Registry for Neonatal Lupus (RNL). Methods: We reviewed fetal echo reports from pregnant STOP BLOQ and RNL Anti-Ro antibody subjects. Pregnancies with high (&gt;1000 EU for anti-Ro52 or 60) antibody titers measured in a core research lab underwent surveillance with home fetal heart rate monitoring (FHRM) 3x/day and weekly or bi-weekly fetal echos from 17- 26 gestational weeks. Low titer subjects underwent echo or no surveillance based on local site protocol. We evaluated cardiac function, effusions, cardiac echogenicity and its location, any tricuspid (TV) or mitral (MV) insufficiency trivial or &gt;trivial) and AV conduction times (&lt;150, 150-170 or &gt;170 ms) Results: Echo reports were available in 622 prospectively followed pregnancies (376 high (40/376 with a previously affected child) and 246 low-titer pregnancies. All had subjectively normal ventricular function and none had effusions. Seven fetuses, 2 low and 5 high titer at 19 (range 16.7-21.7) weeks demonstrated cardiac echogenicity (n=6), AV or semilunar valve insufficiency (n=2) or AV interval 150-170 ms (n=2) (Table). Subjects 1 and 2, both high titer and treated with prophylactic Plaquenil (400 mg/d before 10 gestational weeks), had prior fetal AVB. Subject #1 had normal AV conduction but MV and TV echogenicity and moderate insufficiency of both valves which resolved in days after IVIG and dexamethasone (dex) treatment, but 3° AVB developed at 19 weeks after dex wean. Subjects 2-7 received no treatment and extranodal findings did not progress to cardiac dysfunction or AVB. During the same time period, 10 high titer subjects developed 2° or 3° AVB. Conclusion: Anti-Ro associated extranodal findings are rare, occurring in 1% of pregnancies overall and in 5% of pregnancies with a previously affected child. Unlike AVB, extranodal findings can occur in low titer pregnancies. The role of treatment for isolated extranodal findings in the absence of cardiac dysfunction is unclear.

Experimental in vivo models for understanding inter-molecular interactions and preventing multifactor disease development

The increased spontaneous fragility in the centromere regions of the chromosomes predisposes to abnormal cellular division due to abnormal interaction with the mitotic spindle, which leads to number chromosomal aberrations. The abnormal structure of the microtubule-associated proteins (MAPs) could also be among the internal factors, predisposing to these pathologies. On the other hand, the increased frequency of the spontaneous chromosomal fragility suggests abnormal structure of the respective chromosomal/chromatin components and thus an increased risk about gene mutations and structural chromosomal aberrations. The spontaneous chromosomal fragility was tested by light microscopy observation of metaphases from peripheral blood lymphocytes of 8 patients with polygene pathologies (neoplasms, neuro-degenerative diseases, and neuro-psychiatric disorders) and of 18 healthy controls. In the tested patients was established significantly higher frequency of the spontaneous chromosomal fragility, including in the centromere chromosomal regions, compared to the controls. Different inter-molecular interactions, which could prevent the pathology appearance, were investigated by appropriate experimental in vivo models. As a whole, in the most cases, the presented data showed significantly lower average titers of anti-ganglioside antibodies and gangliosides in the samples from myocardium and liver than in the samples from brain and pancreas. By taking into consideration that the myocardium and liver are known as the most enriched of GSH anatomic organs, the presented data could be explained with the literature messages of higher amounts of de novo-synthesized free GSH tri-peptide in the same two organs. Moreover, a possibility about the production of antibodies/immunoglobulins by non-lymphoid types of cells, tissues, and organs in appropriate conditions was shown. Because the so-produced antibodies are out of the germinative centers in the specialized lymphoid tissues and organs, the control of their functions by small ions and molecules as gangliosides is very important. In the current study, the attention was particularly directed to the iteractions with the participation of gangliosides, the reduced form of the tri-peptide glutathione (GSH), and the protein HACE1. Besides the tumor-suppressor activity of protein HACE1, also its neuroprotective influence was proven, namely by interactions with specific molecules.

Genomic Comparisons Revealed the Key Genotypes of Streptomyces sp. CB03234-GS26 to Optimize Its Growth and Relevant Production of Tiancimycins

Strain robustness and titer improvement are major challenges faced in the industrial development of natural products from Streptomyces. Tiancimycins (TNMs) produced by Streptomyces sp. CB03234 are promising anticancer payloads for antibody-drug conjugates, but further development is severely limited by the low titer of TNMs. Despite many efforts to generate various TNMs overproducers, the mechanisms underlying high TNMs production remain to be explored. Herein, genome resequencing and genomic comparisons of different TNMs overproducers were conducted to explore the unique genotypes in CB03234-GS26. Four target genes were selected for further bioinformatic analyses and genetic validations. The results indicated that the inactivation of histidine ammonia-lyase (HAL) showed the most significant effect by blocking the intracellular degradation of histidine to facilitate relevant enzymatic catalysis and thus improve the production of TNMs. Additionally, the potassium/proton antiporter (P/PA) was crucial for intracellular pH homeostasis, and its deficiency severely impaired the alkaline tolerance of the cells. Subsequent pan-genomic analysis suggested that HAL and P/PA are core enzymes that are highly conserved in Streptomyces. Therefore, HAL and P/PA represented novel targets to regulate secondary metabolism and enhance strain robustness and could become potential synthetic biological modules to facilitate development of natural products and strain improvement in Streptomyces.

Hemagglutination-Inhibition Antibodies and Protection against Influenza Elicited by Inactivated and Live Attenuated Vaccines in Children.

Hemagglutinin (HA)-inhibiting antibodies contribute to the immune defense against influenza infection. However, there are insufficient data on the extent of correlation between vaccine-elicited HA antibodies and protection in children against different influenza strains, particularly when comparing live attenuated influenza vaccines (LAIV) versus inactivated influenza vaccines (IIV). We measured postvaccination hemagglutination-inhibition (HAI) titers in 3-15-year-old participants of a cluster-randomized controlled trial of trivalent LAIV(3) versus IIV(3) in Canadian Hutterite colonies. We assessed HAI titers as predictors of symptomatic, reverse transcription polymerase chain reaction (RT-PCR)-confirmed influenza over 3 influenza seasons using Cox proportional hazards regression models with vaccine type as a covariate. For each log2 unit increase in postvaccination HAI against A/H1N1 in 2013-2014, A/H3N2 2014-2015, and B/Yamagata in 2013-2014 (each the predominant circulating strain for the respective influenza season), the reduction in the risk of confirmed influenza was equal to 29.6% (95% confidence interval [CI], 17.1%-39.5%), 34.8% (95% CI, 17.2%-47.9%), and 31.8% (95% CI, 23.8%-38.5%), respectively. No reduction in the risk of influenza was observed with B/Yamagata-specific HAI titers in 2012-2013, which was dominated by a mixture of Yamagata and Victoria strains. Despite the overall lower HAI titers in the LAIV3 group, both H1N1 and H3N2 HAI titers were associated with protection against subtype matched influenza. Both LAIV3- and IIV3-elicited HA antibodies are associated with protection against influenza infection in seasons when the vaccine strains match the circulating influenza strain subtypes, supporting the use of HAI as a correlate of protection for both vaccine types in children.

Comparative study of neutralizing antibodies titers in response to different types of COVID-19 vaccines among a group of egyptian healthcare workers

BackgroundDefining the protective thresholds against the severe-acute-respiratory-syndrome-related corona virus-2 pandemic is a crucial challenge. To reduce the risks of severe disease, hospitalization, and death, various COVID-19 vaccines have been rapidly developed.Aim of the workThis study aimed to assess the impact of three common COVID-19 vaccine types; two mRNA COVID-19 vaccines: (Pfizer/BioNTech’s BNT162b2 and Moderna’s mRNA-1273), one adenoviral vector vaccine: Oxford/AstraZeneca’s ChAdOx1, and one inactivated vaccine (Sinovac Biotech/China’s Sinovac) on the level of neutralizing antibodies, considering factors such as vaccine type, demographic characteristics, and hybrid immunity. We conducted a direct comparative analysis involving 300 healthcare workers, both with and without prior SARS-CoV-2 infection (B.1, C.36.3, and AY.32 (Delta) variants). Neutralizing antibodies levels were measured at baseline (before vaccination), before the second dose, and six months after the second dose.ResultsThe results showed a significant increase in neutralizing antibodies levels after complete vaccination with all vaccine types. Among healthcare workers, those vaccinated with mRNA vaccines (Moderna or Pfizer) exhibited the highest neutralizing antibodies titers, followed by AstraZeneca, and finally Sinovac with the lowest titer. On studying the effect of previous COVID-19 infection after vaccination, no significant difference in neutralizing antibodies levels was observed between healthcare workers vaccinated with mRNA or AstraZeneca vaccines, both with prior COVID-19 infection, following the first and six months after the second dose.ConclusionThese findings suggest that individuals with prior COVID-19 may only require a single dose of mRNA or AstraZeneca vaccines to achieve a similar level of immunization as those without prior COVID-19 who completed the vaccination program.HighlightsThere is a significant increase in neutralizing antibodies levels after complete vaccination against COVID-19Vaccination with mRNA vaccines exhibits the highest neutralizing antibodies titers.Vaccination with Sinovac exhibits the lowest neutralizing antibodies titers.Graphical abstract

Different patterns of longitudinal changes in antinuclear antibodies titers in children with systemic lupus erythematosus and Sjögren's syndrome.

to investigate the trend of autoantibody titers during a 2-year follow-up in pediatric systemic lupus erythematosus (pSLE) and pediatric Sjögren's syndrome (pSS). Autoantibodies testing was performed every 3-4 months during 2 years from disease onset in a cohort of children with pSLE and pSS. We enrolled 21 children with pSLE and 22 children with pSS. All pSLE patients at 2 years showed ANA titers significantly lower compared to disease onset. Eleven patients (73%) were still ANA positive at 2 years, while 4 (26%) became ANA negative. At diagnosis, 12 (80%) patients showed a homogeneous pattern, while 3 (20%) patients showed a speckled pattern. The latter remained ANA positive with the same pattern; only 2 patients with a homogenous pattern converted to speckled, 4 patients with a homogeneous pattern became ANA negative. ANA negative pSLE patients showed lower levels of interferon score compared to ANA positive patients. Anti-dsDNA titers declined equally in the two groups. All patients with pSS, at disease onset, were ANA and anti-Ro positive and 14 (66%) were anti-La positive. After 2 years of follow-up, 100% remained ANA positive but showed significant lower titers. During follow-up anti-Ro and anti-La titers remained stable. different patterns in changes of ANA and ENA titers in pSLE and pSS were shown. At 2 years of follow-up, all pSLE patients had a lower ANA titer and 26% became negative; however, all pSS patients remained both ANA and ENA positive. This evidence may be due to different pathogenetic pathways in SLE and pSS.

Significance of HBsAg Expression in Placental Tissue with Serum Positivity in Hepatitis B Virus-infected Mother

Introduction: Hepatitis B virus infection in fetal and newborn may result from the intrauterine vertical transmission. The purpose of our study is to determine the association between HBsAg expression in the placental and HBsAg serum in pregnant women. Methods: Total 67 placental tissues and serum were obtained from HBV-infected mothers. This study was conducted in various hospitals in Makassar, Indonesia from December 2017 until August 2018. Maternal serum and placental tissues were tested by ELISA and Immunohistochemistry staining. Results: 67 samples from placental tissues and serum were categorized into two different levels of serum titer and staining positivity. Twenty nine samples (43.3%) were categorized in low titer of HBsAg positive serum and 38 samples (56.7%) in high titer of HBsAg positive serum. From the total of 67 placental samples, 43 (64.2%) samples had positive expression of HBsAg immunohistochemistry staining and 24 (34.8%) samples had negative expressions. Conclusions: There was a significant correlation between the expressions of HBsAg in the placental tissues and serum titers of HBV-infected mothers that is important in predicting the risk of transplacental transmission. The results of this study can be used as guidelines for the prevention and therapeutic approach of mother-to-child HBV infection.

HLA-B*15 Is Associated With SARS-CoV-2 Infection in a Brazilian Population.

Studies have suggested an association between polymorphisms in class I genes of the major histocompatibility complex, specifically the human leukocyte antigen (HLA), and susceptibility to SARS-CoV-2. To explore this, 135 individuals with positive serological tests for SARS-CoV-2 were recruited. All the samples were collected before the advent of vaccines, avoiding immunization effects. Participants were divided into high and low neutralizing antibody titer groups, and polymorphisms in HLA-A, HLA-B, and HLA-DRB1 genes were examined using PCR-SSO. Allele prevalence in the study population was compared to the National Bone Marrow Volunteer Donors Register (REDOME) in São Paulo and between the high and low titer groups within the study population. Results indicated that the HLA-B*15 polymorphism was more prevalent in the COVID-19 positive group compared to the control population (COVID-19 = 0.1370; Control = 0.0875; p = 0.0067). The HLA-B*18 polymorphism was less prevalent in the COVID-19 group (COVID-19 = 0.0185; Control = 0.0534; p = 0.0064). Additionally, the HLA-A*30 polymorphism was more prevalent in the high titer group within the (high = 0.10937; low = 0.02816; p = 0.0125). Other polymorphisms showed no significant differences. These findings align with international studies, suggesting these genes plays a role in COVID-19 pathophysiology, however, further research is required to fully understand their impact.

IGLON5 Frequency in Idiopathic REM Sleep Behavior Disorder: A Multicenter Study.

Idiopathic/isolated REM sleep behavior disorder (iRBD) has been strongly linked to neurodegenerative synucleinopathies such as Parkinson disease, dementia with Lewy bodies, and multiple system atrophy. However, there have been increasing reports of RBD as a presenting feature of serious and treatable autoimmune syndromes, particularly IGLON5. This study's objective was to investigate the frequency of autoantibodies in a large cohort of participants with iRBD. Participants were enrolled in the North American Prodromal Synucleinopathy cohort with polysomnography-confirmed iRBD, free of parkinsonism and dementia. Plasma samples were systematically screened for the autoantibodies IGLON5, DPPX, LGI1, and CASPR2 using plasma IgG cell-based assay. Positive or equivocal results were confirmed by repeat testing, plus tissue-based indirect immunofluorescence assay for IGLON5. Of 339 samples analyzed, 3 participants (0.9%) had confirmed positive IGLON5 autoantibodies in the cell-based assay, which were confirmed by the tissue-based assay. An additional participant was positive for CASPR2 with low titer by cell-based assay only (of lower clinical certainty). These cases exhibited a variety of symptoms including dream enactment, cognitive decline, autonomic dysfunction, and motor symptoms. In 1 IGLON5 case and the CASPR2 case, evolution was suggestive of typical synucleinopathy, suggesting the possibility that findings were incidental. However, 2 participants with IGLON5 died before diagnosis was clinically suspected, with a final clinical picture highly suggestive of autoimmune disease. Our finding that nearly 1% of a large iRBD cohort may have a serious but potentially treatable autoantibody syndrome has important clinical implications. In particular, it raises the question of whether autoantibody testing for IGLON-5-IgG should be widely implemented for participants with iRBD, considering the difficulty in diagnosis of autoimmune diseases, their response to treatment, and the potential for rapid disease progression. However, any routine testing protocol will also have to consider costs and potential adverse effects of false-positive findings. NCT03623672.

Assessing humoral immunity in daily practice: A retrospective study in a pediatric tertiary center

The evaluation of humoral immunity is usually performed through the assessment of serum immunoglobulin levels, vaccine titer responses, and B-cell enumeration and phenotyping. We performed a retrospective study assessing humoral immunity in 469 pediatric patients referred at the Sainte-Justine University Hospital Center. Almost half of the patients had at least one abnormal humoral immunological parameter at their evaluation, with low vaccine response titer to protein antigen being the most frequent. Fifteen patients (3.2 %) had a proven monogenic IEI, and 21 patients (4.5 %) required Ig replacement. Besides the infectious burden, hypoIgG remains the only parameter associated with Ig replacement therapy after the age of 6 years. Low antibody titers against conjugate vaccines had low sensitivity and positive predictive values for starting Ig replacement. Our study highlights the challenge of evaluating the humoral function in the pediatric population with suspected IEI with significant age and sex-dependent variability between parameters.

Synergistic effects of Lianhuaqingwen in combination with Oseltamivir and Baloxavir against seasonal influenza virus: in vitro and in vivo assessment

Ethnopharmacological relevanceLianhuaqingwen (LH), a traditional Chinese medicine, presents a broad-spectrum antiviral effect and has been widely used to treat influenza. Given the potential rise of drug-resistant influenza viruses, it is necessary to develop new antiviral drugs and explore combination therapies involving LH in tandem with existing antivirals such as Oseltamivir acid (Osel) or Baloxavir (Bal). These multidrug combinations could help effectively control the seasonal influenza epidemics and reduce the disease burden. Aim of the studyThis study aimed to evaluate the antiviral effects of LH, alone and in combination with Osel or Bal, against human seasonal influenza viruses in vitro and in vivo models. Materials and methodsThe antiviral efficacy of LH alone and LH in combination with Osel/Bal against seasonal influenza A viruses (IAVs) (H1N1 and H3N2 subtypes) and influenza B viruses (IBVs) (BV- and BY-lineages) was assessed in vitro using MDCK cells. The median effective concentration (EC50) was determined, and the drug synergies were analyzed. Additionally, the antiviral activity of LH monotherapy and LH + Osel/Bal combination therapy were evaluated in vivo using an H1N1-infected BABL/c mouse model by monitoring changes in body weight, survival rate, lung viral titer, pathological damage, and inflammatory reaction. ResultsIn vitro, LH alone and in combination with Osel/Bal exhibited antiviral activity against both IAVs and IBVs. The addition of LH to Osel/Bal improved the therapeutic efficacy compared to Osel/Bal alone. In vivo, LH monotherapy reduced body weight loss and increased the survival rates of H1N1-infected mice. LH in combination with Osel/Bal resulted in lower virus titers, more effective relief of pathological damage, and comparable low expression of inflammatory factors in the lungs of H1N1-infected mice compared to the use of Osel/Bal alone. Transcriptomic analysis of the lungs revealed that LH+Osel/Bal significantly increased the expression of genes associated with antiviral and anti-inflammatory effects. ConclusionsThis study evaluated the antiviral effects of LH monotherapy and combination therapy with Osel/Bal against human seasonal influenza viruses in vitro and in vivo models. The results suggest that combining LH with Osel or Bal could enhance the antiviral efficiency for influenza viruses compared to the monotherapy using any of these three drugs.

OA08 Ocrelizumab in pregnancy in a patient with juvenile onset systemic lupus erythematosus

Abstract Introduction Juvenile-onset systemic lupus erythematosus (jSLE) is a multisystem autoimmune disease that results in increased disease activity compared to adult-onset SLE. jSLE in pregnancy results in a greater incidence of disease flares as well as adverse pregnancy outcomes. Management of SLE in pregnancy is particularly difficult due to lack of safety data for immunosuppressant medications and is therefore limited. Ocrelizumab is a humanised monoclonal antibody that selectively targets CD20 B cells and is approved for the treatment of multiple sclerosis. Despite never being trialled in a patient with active SLE in pregnancy, this case demonstrates its use with a successful outcome. Case description An 18-year-old female was diagnosed at age 14 with juvenile onset systemic lupus erythematosus with the presence of a photosensitive malar rash, arthralgia, alopecia, aphthous ulcers and headache. At the time of diagnosis her investigations revealed ANA 1:5120 with homogenous pattern, high dsDNA, low C3 and C4, thrombocytopenia, antibodies to Smith, Ro, RNP, anti-Rib-P, strongly positive lupus anticoagulant antibodies and low titre anti-cardiolipin IgG and IgM. Previous treatment included methotrexate, mycophenolate mofetil and cyclosporin which were discontinued either due to patient choice, inefficacy or adverse reaction. Azathioprine was contraindicated due to low TMPT. Rituximab was trialled and although effective had to be stopped due to adverse reaction. Unfortunately, she experienced a primigravida pregnancy loss at 15-20 weeks secondary to active SLE and pre-eclampsia. Shortly after this, she developed a rare case of anti-fascin antibody neuropathy and was treated with ocrelizumab. Six months later during her second pregnancy, she was treated with hydroxychloroquine 400 mg, aspirin 150 mg, folic acid 5 mg and low molecular weight heparin prophylaxis which were continued throughout the pregnancy. Due to concerns of active lupus at 13 weeks due to facial rash and fatigue, prednisolone was commenced at 10 mg daily and continued. After careful consideration, Ocrelizumab was given in the second trimester at 17 and 19 weeks’ gestation. Following this, symptoms remained under control and disease activity was low with normal C3/C4 and dsDNA levels without significant proteinuria. A newborn baby was delivered at 38 weeks by caesarean section without complication or foetal abnormalities. Both the mother and baby remain under close follow- up but have not demonstrated adverse outcomes at 3 months postpartum. Discussion This case demonstrates the use of Ocrelizumab in the second trimester of a high-risk pregnancy complicated by active jSLE. At present, there is no license for use of Ocrelizumab in SLE and no safety data on its use in pregnancy. However, there was a good outcome for this patient which resulted in no antenatal or postpartum complications and the successful birth of a healthy newborn without foetal abnormalities. Ocrelizumab is used for the treatment of early relapsing-remitting multiple sclerosis (RRMS) and is increasingly used by neurologists in women of childbearing age despite being unlicensed for use in pregnancy. Concerns of its use in pregnancy surround B cell depletion in the neonate which while tends to be transient, causes significant concern regarding long term immunological development and response to vaccination. B cell depleting therapies are widely used in the context of active and refractory SLE and therefore use of Ocrelizumab has been evaluated in cases of SLE in two phase III clinical trials. The first study examined the efficacy of Ocrelizumab in SLE without renal involvement (BEGIN) and the second recruited patients with lupus nephritis (BELONG). The BEGIN study was terminated early due to lack of response and the BELONG study was terminated due to a significant increase in serious infections (in the Ocrelizumab plus mycophenolate treatment group). However, results on disease activity were positive with complete renal response being achieved non-statistically more frequently in the Ocrelizumab treated patients versus placebo. Real world evidence shows the importance of achieving disease control in SLE around pregnancy to prevent adverse outcomes. The decision for the use of Ocrelizumab therefore needs to be balanced carefully against potential harm to the baby either from direct foetal exposure to the drug, or from gestation in an immunocompromised mother. Key learning points • Pre-pregnancy counselling is of paramount importance in severe cases of active SLE and when possible, pregnancy should be postponed in these instances until disease activity is stabilised with contraception counselling offered to those on teratogenic immunosuppressive agents. • A multidisciplinary approach to the management of complex SLE in pregnancy in essential with obstetrician, midwife, maternal medicine physician and rheumatologist input. • The benefit of potentially life-saving immunosuppressive treatment should be carefully balanced against the poor outcomes of active SLE in pregnancy and decisions should be made on a case-by-case basis.

Bartonella endocarditis: lessons learnt from an African cohort

Abstract Background Bartonella (B) quintana endocarditis is a preventable, vector-borne, and important cause of blood culture-negative endocarditis (BCNE). The ESC guideline for the management of endocarditis recommends blood serology (IgG titer ≥800) and polymerase chain reaction (PCR) testing on both blood and valvular tissue for diagnosis. Access to these molecular technologies is limited in Africa and there is a paucity of B. quintana endocarditis research on the continent. Purpose Record the clinical picture and explore the risk factors for disease and the diagnostic utility of immunofluorescence (IFA) in PCR-proven cases with B. quintana endocarditis. Methods Data were analysed from a prospective observational cohort study of patients with infective endocarditis managed at our institution. All BCNE cases from October 2019 to January 2024 were evaluated to identify patients with PCR-proven B. quintana on valvular tissue. A commercially available IFA was used for blood serology testing. 16S rRNA PCR testing with sequencing was performed on valvular tissue. Results Thirty five of the 58 cases (60.3%) with BCNE were diagnosed with Bartonella endocarditis. A diagnosis of PCR-proven B. quintana endocarditis was made in 21 cases. Of these, seven patients (33.3%) were either homeless or lived in informal housing. Thirteen patients (61.9%) had an alcohol-use disorder. Four patients (19%) were Human Immunodeficiency (HIV) virus- positive. Eighteen patients (85.7%) reported the onset of symptoms more than two weeks before presentation. Common presenting symptoms were dyspnea (n=21;100%), loss of weight (n=10;47.6%) and fever (n=7;33.3%). Common clinical features were digital clubbing (n=17;80.9%), pallor (n=13; 61.9%), microscopic haematuria (n=12; 57.1%) and severe regurgitant lesions (n=21; 100%). Blood serology was available in 17 patients with an IgG titer (1≥256) in all patients apart from one (1:64). Only one case (5.8%) had an IgG titre ≥800. The most common isolated valve lesion on echocardiography was severe aortic regurgitation (n=10;47.6%). Surgical replacement and repair were performed in 17(80.9%) and 4(19%) patients respectively. The one-, three- and six-month mortality was 14%, 14 % and 14% respectively. No cases of relapse were reported. Discussion B.quintana is the most prevalent cause of BCNE in our centre. The typical clinical and echocardiographic profile was consistent with the reported literature of a destructive endocarditis in a patient with a low socioeconomic background. Despite this, the surgical outcome is fair and comparable to European data. The IFA used in this study is different to the assay referenced in the ESC guideline and may explain the relatively low serology titres observed (despite PCR-proven disease). Further study with the commercial IFA is needed to determine a cut-off titre that will give a comparable sensitivity to the referenced in-house IFA.Destructive aortic valve endocarditisResultant severe aortic regurgitation

Immunogenicity to Herpes Zoster recombinant subunit vaccine in immune-mediated rheumatic patients under treatment with JAK inhibitors.

Patients with immune-mediated rheumatic diseases (IMRDs) face an elevated risk of varicella-zoster virus infection (VZV), and herpes zoster (HZ). Treatment with immunosuppressors further increases the risk. A new recently approved adjuvant recombinant inactive vaccine, offers safe protection against HZ. However, limited data exist on the efficacy of this new vaccine in patients with IMRDs treated with JAK inhibitors. We aimed to characterize B cell and T cell immune responses elicited by the HZ recombinant subunit vaccine in patients with IMRDs under treatment with JAK inhibitors, and to identify factors that might be associated with reduced immunogenicity, and therefore reduced protection. We investigated humoral, and cellular CD4 and CD8 immune responses following a two-dose regimen of the recombinant inactive vaccine in 43 patients with rheumatic diseases treated with different JAK inhibitors. The responses were compared with age, gender and disease-matched healthy controls. Patients with IMRDs treated with JAK inhibitors showed reduced seroconversion rate (63% vs 100% and lower VZV IgG titers (1222 ± 411 vs 3048 ± 556, p< 0.0001) as compared with healthy controls. Functional T CD4 (IL-2 plus IFN-γ secretion) and T CD8 (Granzyme A and/or Granzyme B secretion) immune responses were also significantly diminished in IMRDs patients. Negative correlation was found between VZV antibody titers and age, specific treatments (baricitinib, tofacitinib, upadacitinib), cumulative methotrexate and glucocorticoid doses, history of multiple DMARDs, and treatment duration with JAK inhibitors. Functional T-CD4 responses but not functional T-CD8 responses also showed similar negative correlations. Positive associations were observed between functional T-CD4 and T-CD8 responses. Our study provides valuable insights into the immune responses elicited by the recombinant inactive vaccine in patients with IMRDs treated with JAK inhibitors. In these patients we have observed a broad impact on the adaptive humoral and cellular immune responses, suggesting a potential reduction in protection against herpes zoster infection and VHZ reactivation.

Serum interleukin-10 level is increased and correlated positively with disease severity in patients with dipeptidyl peptidase-4 inhibitor-related bullous pemphigoid.

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease with a linear deposit of autoantibodies at the epidermal basement membrane zone. It was reported that diabetes patients who took a dipeptidyl peptidase-4 inhibitor (DPP4i), an oral antidiabetic drug, had an increased incidence of BP. However, data on DPP4i-related BP are limited. In our study, we measured serum levels of various cytokines using LEGENDplex and assessed correlations of these serum levels with clinical severity and laboratory data. Serum samples obtained from BP patients who visited our hospital from June 2016 to February 2023 were collected in this study. Patients' background, characteristics, and clinical data were retrospectively collected from their charts. Serum samples from 27 patients with DPP4i-unrelated BP, 17 patients with DPP4i-related BP, and 13 healthy controls were analyzed. Patients with DPP4i-related BP had lower score of Bullous Pemphigoid Disease Area Index (BPDAI)-erythema/urticaria, lower number of circulating eosinophils, and lower titer of anti-BP180 antibody than patients with DPP4i-unrelated BP. The serum interleukin (IL)-6 level was significantly higher in patients with DPP4i-related BP than in healthy controls (P = 0.0037). The serum IL-10 level was significantly higher in patients with DPP4i-related BP than in patients with DPP4i-unrelated BP and in healthy controls (P = 0.0006, P = 0.0448), and was positively correlated with the BPDAI-blister/erosions score (r = 0.757, P = 0.001), BPDAI-erythema/urticaria score (r = 0.616, P = 0.013), and BPDAI-total score (r = 0.833, P < 0.001) in patients with DPP4i-related BP. In conclusion, patients with DPP4i-related BP had increased serum levels of IL-6 and IL-10 compared with healthy controls and positive correlations between the serum IL-10 level and BPDAI scores reflecting clinical severity, indicating that the serum IL-10 level is a potential objective biomarker of disease severity in patients with DPP4i-related BP.

Cellular and humoral immunity and IgG subclass distribution after omicron XBB.1.5 monovalent vaccination in Japan

BackgroundUp to seven doses of coronavirus disease 2019 (COVID-19) mRNA vaccines (BNT162b2) were administered to Japanese healthcare workers, until February 2024. The monovalent Omicron XBB.1.5 vaccine (hereafter called XBB.1.5 vaccine) was used for dose 7. ObjectiveAlthough the XBB.1.5 vaccine has been reported to induce a robust increase in neutralizing antibodies against the currently circulating Omicron variant BA.2.86, little is known about its serological effects in Japan, where the BNT162b2 mRNA vaccine is the most frequently administered in the world. Study designTwenty-five recipients of the XBB.1.5 vaccine, categorized as seronegative (n = 18) or seropositive (n = 7) based on their recent history of COVID-19, were analyzed. Neutralizing antibody titers against Omicron subvariants, receptor binding domain (RBD) IgG levels, IgG subclass distribution, and T-cell responses were assessed. ResultsWe found a significant increase in neutralizing antibody titers against XBB.1.5 and BA.2.86 variants following XBB.1.5 vaccination, particularly in seropositive individuals. No significant change in total RBD IgG levels was observed, indicating efficient induction of antibodies targeting regions outside the RBD by XBB.1.5 vaccination. IgG subclass analysis demonstrated no significant subclass switching after vaccination. T-cell responses against the virus were comparable between seropositive and seronegative groups. ConclusionsThe study suggests that XBB.1.5 vaccination enhances humoral immunity against Omicron variants without significant IgG subclass switching. However, some individuals with low pre-vaccination IgG titers did not exhibit increased antibody levels post-vaccination, raising concerns about potential immune tolerance.

Monoclonal Membranous Glomerulopathy in a Patient with Positive Serology for Lupus Nephritis

Abstract Introduction/Objective Monoclonal membranous glomerulopathy (M-MGN) is a rare entity; only two reports are available in the literature. Monoclonal membranous glomerulopathy has been called either monoclonal immunoglobulin deposition disease associated with membranous features in a 3-patient small series report or membranous glomerulopathy with light chain restriction in another larger series with 28 cases. We report M-MGN in a patient with positive serology lupus. Methods/Case Report The patient was a 74-year-old man with hypertension and nephrotic range proteinuria (protein/creatinine ratio at 8.5). His serum creatinine remained normal at 0.6 mg/dL. The patient was positive for double-stranded DNA and ANA at low titer, but had reduced complement C3 and C4. Immunofixation was negative for monoclonal protein. The light microscopy of the renal biopsy revealed thickened loops of glomeruli with mild interstitial nephritis. Immunofluorescent studies showed a positive linear/granular pattern of IgG and lambda but negative kappa staining along the glomerular loops. Electron microscopy revealed smooth contoured stage 2 subepithelial deposits. An outside consultation confirmed our diagnosis and found IgG2 restriction in glomeruli. Electrophoresis revealed no monoclonal protein in the serum. Results (if a Case Study enter NA) NA Conclusion Our patient demonstrated M-MGN with mild interstitial nephritis; the latter may be related to his lupus status. As 30% of patients with M-MGN have either monoclonal serology or B-cell lymphoproliferative disorders, with most having a restricted IgG subtyping, a close follow-up and even chemotherapy for a B-cell clone should be considered.

Pediatric safety profile of low titer O whole blood with increasing Anti-A and Anti-B titers

Abstract Objectives To add additional evidence to the safety of using low-titer O whole blood (LTOWB) in the massively hemorrhaging pediatric population, even with increasing allowance of anti-A and anti-B titers, up to 200. Methods A retrospective review from December 2021 to March 2023 of the blood bank and surgical massive transfusion protocols was performed with IRB approval to identify patients less than 18 years old who had received LTOWB as part of trauma resuscitation. In addition to patient characteristics, volume of LTOWB and other components were assessed, as well as Day 1-3 of serum potassium, creatinine, and total bilirubin. Wilcoxon rank-sum tests were performed to compare continuous variables and Fisher’s exact tests were performed to compare categorical variables between group O blood groups patients and non-O blood group patients. Results Only ten patients were identified under 18 years of age who had received LTOWB during trauma resuscitation, with five being blood group O and five non-O. Patient characteristics were similar between the two groups; however, only 10% were female and 10% self-reported as Black or African American. Age in the non-O group was 15 +/- 3.0 and 16.2 +/- 1.3 in the O group, p=0.75. Weight was 56.16 kg +/- 7.17 in the non-O group and 64.02+/- 14.23 in the O group, p=0.35. LTOWB transfused was 10.46 mL/kg +/- 2.42 in the non-O group and 10.32 +/- 6.53 in the O group, p=0.25. Potassium, creatinine, and total bilirubin were similar on Days 1-3 in both groups, except a single high total bilirubin in the non-O group, and this value normalized on Day 3. Conclusion A small data set was extracted from the available massive transfusion protocol data, reflecting the small amount of pediatric patients requiring massive transfusion for trauma compared to adults. Moreover, the predominance of males requiring massive transfusion for trauma corresponds with general trauma trends in the United States. These data reflect and are similar to previous safety reviews of pediatric trauma patients receiving LTOWB. This retrospective review records, however, a time period when the titer of anti-A and anti-B had been relaxed to 200 (rather than 50 in previous studies). This study, although small, reflects an additional Level I trauma site delivering LTOWB at potentially higher titers without negative sequelae in potassium, creatinine, or total bilirubin. With upcoming randomized controlled trials, such as Massive Transfusion in Children (MATIC-2), these data continue to reassure that the practice of using LTOWB is likely safe during the resuscitation period.

LysoPE mediated by respiratory microorganism Aeromicrobium camelliae alleviates H9N2 challenge in mice

Influenza remains a severe respiratory illness that poses significant global health threats. Recent studies have identified distinct microbial communities within the respiratory tract, from nostrils to alveoli. This research explores specific anti-influenza respiratory microbes using a mouse model supported by 16S rDNA sequencing and untargeted metabolomics. The study found that transferring respiratory microbes from mice that survived H9N2 influenza to antibiotic-treated mice enhanced infection resistance. Notably, the levels of Aeromicrobium were significantly higher in the surviving mice. Mice pre-treated with antibiotics and then inoculated with Aeromicrobium camelliae showed reduced infection severity, as evidenced by decreased weight loss, higher survival rates, and lower lung viral titres. Metabolomic analysis revealed elevated LysoPE (16:0) levels in mildly infected mice. In vivo and in vitro experiments indicated that LysoPE (16:0) suppresses inducible nitric oxide synthase (INOS) and cyclooxygenase-2 (COX2) expression, enhancing anti-influenza defences. Our findings suggest that Aeromicrobium camelliae could serve as a potential agent for influenza prevention and a prognostic marker for influenza outcomes.