Emerging and re-emerging pediatric viral diseases: a continuing global challenge

The twenty-first century has been marked by a surge in viral epidemics and pandemics, highlighting the global health challenge posed by emerging and re-emerging pediatric viral diseases. This review article explores the complex dynamics contributing to this challenge, including climate change, globalization, socio-economic interconnectedness, geopolitical tensions, vaccine hesitancy, misinformation, and disparities in access to healthcare resources. Understanding the interactions between the environment, socioeconomics, and health is crucial for effectively addressing current and future outbreaks. This scoping review focuses on emerging and re-emerging viral infectious diseases, with an emphasis on pediatric vulnerability. It highlights the urgent need for prevention, preparedness, and response efforts, particularly in resource-limited communities disproportionately affected by climate change and spillover events. Adopting a One Health/Planetary Health approach, which integrates human, animal, and ecosystem health, can enhance equity and resilience in global communities. IMPACT: We provide a scoping review of emerging and re-emerging viral threats to global pediatric populations This review provides an update on current pediatric viral threats in the context of the COVID-19 pandemic This review aims to sensitize clinicians, epidemiologists, public health practitioners, and policy stakeholders/decision-makers to the role these viral diseases have in persistent pediatric morbidity and mortality.

Retrospective Review of Blood Culture-Confirmed Cases of Enteric Fever in Navi Mumbai, India: 2014-2018

India has one of the highest estimated burdens of enteric fever globally. Prior to the implementation of Typbar-TCV typhoid conjugate vaccine (TCV) in a public sector pediatric immunization campaign in Navi Mumbai, India, we conducted a retrospective review of blood culture-confirmed cases of typhoid and paratyphoid fevers to estimate the local burden of disease. This review included all blood cultures processed at a central microbiology laboratory, serving multiple hospitals, in Navi Mumbai (January 2014-May 2018) that tested positive for either Salmonella Typhi or Salmonella Paratyphi A. Of 40,670 blood cultures analyzed, 1,309 (3.2%) were positive for S. Typhi (1,201 [92%]) or S. Paratyphi A (108 [8%]). Culture positivity was highest in the last months of the dry season (April-June). Our findings indicate a substantial burden of enteric fever in Navi Mumbai and support the importance of TCV immunization campaigns and improved water, sanitation, and hygiene.

Population structure and antimicrobial resistance patterns of Salmonella Typhi and Paratyphi A amid a phased municipal vaccination campaign in Navi Mumbai, India

We performed whole-genome sequencing of 174 Salmonella Typhi and 54 Salmonella Paratyphi A isolates collected through prospective surveillance in the context of a phased typhoid conjugate vaccine introduction in Navi Mumbai, India. We investigate the temporal and geographical patterns of emergence and spread of antimicrobial resistance. We evaluated the relationship between the spatial distance between households and genetic clustering of isolates. Most isolates were non-susceptible to fluoroquinolones, with nearly 20% containing ≥3 quinolone resistance-determining region mutations. Two H58 isolates carried an IncX3 plasmid containing blaSHV-12, associated with ceftriaxone resistance, suggesting that the ceftriaxone-resistant isolates from India independently evolved on multiple occasions. Among S. Typhi, we identified two main clades circulating (2.2 and 4.3.1 [H58]); 2.2 isolates were closely related following a single introduction around 2007, whereas H58 isolates had been introduced multiple times to the city. Increasing geographic distance between isolates was strongly associated with genetic clustering (odds ratio [OR] = 0.72 per km; 95% credible interval [CrI]: 0.66-0.79). This effect was seen for distances up to 5 km (OR = 0.65 per km; 95% CrI: 0.59-0.73) but not seen for distances beyond 5 km (OR = 1.02 per km; 95% CrI: 0.83-1.26). There was a non-significant reduction in odds of clustering for pairs of isolates in vaccination communities compared with non-vaccination communities or mixed pairs compared with non-vaccination communities. Our findings indicate that S. Typhi was repeatedly introduced into Navi Mumbai and then spread locally, with strong evidence of spatial genetic clustering. In addition to vaccination, local interventions to improve water and sanitation will be critical to interrupt transmission. IMPORTANCE Enteric fever remains a major public health concern in many low- and middle-income countries, as antimicrobial resistance (AMR) continues to emerge. Geographical patterns of typhoidal Salmonella spread, critical to monitoring AMR and planning interventions, are poorly understood. We performed whole-genome sequencing of S. Typhi and S. Paratyphi A isolates collected in Navi Mumbai, India before and after a typhoid conjugate vaccine introduction. From timed phylogenies, we found two dominant circulating lineages of S. Typhi in Navi Mumbai-lineage 2.2, which expanded following a single introduction a decade prior, and 4.3.1 (H58), which had been introduced repeatedly from other parts of India, frequently containing "triple mutations" conferring high-level ciprofloxacin resistance. Using Bayesian hierarchical statistical models, we found that spatial distance between cases was strongly associated with genetic clustering at a fine scale (<5 km). Together, these findings suggest that antimicrobial-resistant S. Typhi frequently flows between cities and then spreads highly locally, which may inform surveillance and prevention strategies.

Programmatic Effectiveness of a Pediatric Typhoid Conjugate Vaccine Campaign in Navi Mumbai, India

BACKGROUND

The WHO recommends vaccines for prevention and control of typhoid fever, especially where antimicrobial-resistant typhoid circulates. In 2018 the Navi Mumbai Municipal Corporation (NMMC), implemented a TCV campaign. The campaign targeted all children aged 9-months through 14-years within NMMC boundaries (∼320,000 children) over 2 vaccination phases. The phase 1 campaign occurred from July 14-August 25, 2018 (71% coverage, ∼113,420 children). We evaluated the phase 1 campaign's programmatic effectiveness in reducing typhoid cases at the community level.

METHODS

We established prospective, blood culture-based surveillance at 6 hospitals in Navi Mumbai, offering blood cultures to children presenting with fever ≥ 3 days. We employed a cluster-randomized (by administrative boundary) test-negative design to estimate the effectiveness of the vaccination campaign on pediatric typhoid cases. We matched test-positive, culture-confirmed typhoid cases with up to 3 test-negative, culture-negative controls by age and date of blood culture and assessed community vaccine campaign phase as an exposure using conditional logistic regression.

RESULTS

Between September 1, 2018-March 31, 2021, we identified 81 typhoid cases and matched these with 238 controls. Cases were 0.44 times as likely to live in vaccine campaign communities (programmatic effectiveness, 56%, 95%CI: 25%-74%, p=0.002). Cases ≥ 5-years-old were 0.37 times as likely (95% CI: 0.19-0.70; p-value = 0.002) and cases during the first year of surveillance were 0.30 times as likely (95% CI: 0.14-0.64; p-value = 0.002) to live in vaccine campaign communities.

CONCLUSIONS

Our findings support the use of TCV mass vaccination campaigns as effective population-based tools to combat typhoid fever.

Chronic Salmonella Typhi carriage at sites other than the gallbladder

Typhoid fever caused by infection with Salmonella enterica subspecies enterica serotype Typhi (S. Typhi), an important public health problem in many low- and middle-income countries, is transmitted by ingestion of water or food contaminated by feces or urine from individuals with acute or chronic S. Typhi infection. Most chronic S. Typhi carriers (shedding for ≥12 months) harbor infection in their gallbladder wherein preexisting pathologies, particularly cholelithiasis, provide an environment that fosters persistence. Much less appreciated is the existence of non-gallbladder hepatobiliary chronic S. Typhi carriers and urinary carriers. The former includes parasitic liver flukes as a chronic carriage risk factor. Chronic urinary carriers typically have pathology of their urinary tract, with or without renal or bladder stones. Even as the prevalence of multidrug-resistant and extensively drug-resistant S. Typhi strains is rising, global implementation of highly effective typhoid vaccines is increasing. There is also renewed interest in identifying, monitoring, and (where possible) treating chronic carriers who comprise the long-term reservoir of S. Typhi.

Point-of-Care Ultrasound by Nonexpert Operators Demonstrates High Sensitivity and Specificity in Detecting Gallstones: Data from the Samoa Typhoid Fever Control Program

Approximately 90% of chronic typhoid carriers with persistent Salmonella enterica serovar Typhi (S. Typhi) gallbladder infection have gallstones. In Samoa, where typhoid fever has been endemic for many decades, risk factors predisposing to the development of gallstones are increasing among adults. The Samoa Typhoid Fever Control Program dispatches a "Typhoid Epidemiologic SWAT Team" to perform a household investigation of every blood culture-confirmed case of acute typhoid fever. Investigations include screening household contacts to detect chronic carriers. Following limited training, two nonexpert ultrasound operators performed point-of-care ultrasound (POCUS) on 120 Samoan adults from August to September 2019 to explore the feasibility of POCUS to detect individuals with gallstones during household investigations and community screenings. POCUS scans from 120 Samoan adults in three cohorts (28 food handlers, two typhoid cases and their 18 household contacts, and 72 attendees at an ambulatory clinic) were reviewed by a board-certified radiologist who deemed 96/120 scans (80%) to be interpretable. Compared with the radiologist (gold standard), the nonexpert operators successfully detected 6/7 Samoans with gallstones (85.7% sensitivity) and correctly identified 85/89 without gallstones (95.5% specificity). The proportion (24/120) of uninterpretable scans from this pilot that used minimally trained clinicians (who are neither radiologists nor ultrasound technicians) indicates the need for additional training of POCUS operators. Nevertheless, this pilot feasibility study engenders optimism that in the Samoan setting nonexperts can be trained to use POCUS to diagnose cholelithiasis, thereby helping (along with stool cultures and Vi serology) to identify possible chronic S. Typhi carriers.

SARS-CoV-2 Neutralization Resistance Mutations in Patient with HIV/AIDS, California, USA

We report persistent severe acute respiratory syndrome coronavirus 2 infection in a patient with HIV/AIDS; the virus developed spike N terminal domain and receptor binding domain neutralization resistance mutations. Our findings suggest that immunocompromised patients can harbor emerging variants of severe acute respiratory syndrome coronavirus 2.

Tenacious Endemic Typhoid Fever in Samoa

Background

Typhoid fever has been endemic on the island nation of Samoa (2016 population, 195 979) since the 1960s and has persisted through 2019, despite economic development and improvements in water supply and sanitation.

Methods

Salmonella enterica serovar Typhi isolates from the 2 hospitals with blood culture capability and matched patient demographic and clinical data from January 2008 through December 2019 were analyzed. Denominators to calculate incidence by island, region, and district came from 2011 and 2016 censuses and from 2017–2019 projections from Samoa’s Bureau of Statistics. Data were analyzed to describe typhoid case burden and incidence from 2008 to 2019 by time, place, and person.

Results

In sum, 53–193 blood culture-confirmed typhoid cases occurred annually from 2008 to 2019, without apparent seasonality. Typhoid incidence was low among children age < 48 months (17.6–27.8/10⁵), rose progressively in ages 5–9 years (54.0/10⁵), 10–19 years (60.7–63.4/10⁵), and 20–34 years (61.0–79.3/10⁵), and then tapered off; 93.6% of cases occurred among Samoans < 50 years of age. Most typhoid cases and the highest incidence occurred in Northwest Upolu, but Apia Urban Area (served by treated water supplies) also exhibited moderate incidence. The proportion of cases from short-cycle versus long-cycle transmission is unknown. Samoan S. Typhi are pansusceptible to traditional first-line antibiotics. Nevertheless, enhanced surveillance in 2019 detected 4 (2.9%) deaths among 140 cases.

Conclusions

Typhoid has been endemic in Samoa in the period 2008–2019. Interventions, including mass vaccination with a Vi-conjugate vaccine coadministered with measles vaccine are planned.

Miliary pattern on chest imaging as a presentation of EGFR-negative primary lung adenocarcinoma

A 64-year-old African American man, with a history of prostate adenocarcinoma treated in 2009 and a greater than 50-pack-year tobacco smoking history, presented with 2-3 weeks of non-productive cough, frontal headache and generalised myalgias and arthralgias. CT was positive for diffuse, miliary opacities in bilateral lung fields. He was diagnosed with stage four lung adenocarcinoma, negative for epidermal growth factor receptor (EGFR) gene mutation. The patient was unable to tolerate therapy and passed away approximately 4 months after his diagnosis. Previous case reports and research have suggested an association between EGFR gene mutation and miliary patterned lung metastases in non-small cell lung cancer. This case suggests that the mechanism by which miliary patterned metastases occur is more complex than purely mutation of the EGFR gene. Further study may elucidate novel molecular targets for treatment, especially in patients with rapidly progressive disease such as the patient we describe.

Female Anopheles gambiae antennae: increased transcript accumulation of the mosquito-specific odorant-binding-protein OBP2

Background

New interventions are required to optimally and sustainably control the Anopheles sp. mosquitoes that transmit malaria and filariasis. The mosquito olfactory system is important in host seeking (transmission) and mate finding (reproduction). Understanding olfactory function could lead to development of control strategies based on repelling parasite-carrying mosquitoes or attracting them into a fatal trap.

Findings

Our initial focus is on odorant binding proteins with differential transcript accumulation between female and male mosquitoes. We report that the odorant binding protein, OBP2 (AGAP003306), had increased expression in the antennae of female vs. male Anopheles gambiae sensu stricto (G3 strain). The increased expression in antennae of females of this gene by quantitative RT-PCR was 4.2 to 32.3 fold in three independent biological replicates and two technical replicate experiments using A. gambiae from two different laboratories. OBP2 is a member of the vast OBP superfamily of insect odorant binding proteins and belongs to the predominantly dipteran clade that includes the Culex oviposition kairomone-binding OBP1. Phylogenetic analysis indicates that its orthologs are present across culicid mosquitoes and are likely to play a conserved role in recognizing a molecule that might be critical for female behavior.

Conclusions

OBP2 has increased mRNA transcript accumulation in the antennae of female as compared to male A. gambiae. This molecule and related molecules may play an important role in female mosquito feeding and breeding behavior. This finding may be a step toward providing a foundation for understanding mosquito olfactory requirements and developing control strategies based on reducing mosquito feeding and breeding success.

Consultations after elimination of payments for evaluation and management consultation codes

A consultation service provides expert opinion or advice at the request of another provider. The Centers for Medicare and Medicaid Services (CMS) eliminated reimbursement for the outpatient and inpatient consultation codes traditionally used to report these services (CPT 99241-99245 and 99251-99255, respectively), and private payers are likely to follow suit. CMS has instead mandated that these services are mapped to new or established visit codes for outpatients (99201-99205 or 99212-99215) and to initial or subsequent hospital services codes for inpatients (99221-99223 or 99231-99233). This article reviews appropriate medical consultation and provides specific guidance for the reporting of these services to CMS and other payers not reimbursing consultation codes.

Circulating brain-reactive autoantibodies and behavioral deficits in the MRL model of CNS lupus

Brain-reactive autoantibodies (BRAA) are hypothesized to play a role in the neuropsychiatric manifestations that accompany systemic lupus erythematosus (SLE). The present study tests the proposed relation between circulating BRAA and behavioral deficits in lupus-prone MRL/lpr mice. Two age-matched cohorts born at different times were used to test the relationship in the context of altered disease severity. Significant correlations between autoimmunity and behavior were detected in both cohorts. These results are the first to report correlations between behavior and autoantibodies to integral membrane proteins of brain, supporting the hypothesis that BRAA contribute to the behavioral dysfunction seen in lupus.

Higher dimensional (Hi-D) separation strategies dramatically improve the potential for cancer biomarker detection in serum and plasma

The plasma proteome has a wide dynamic range of protein concentrations and is dominated by a few highly abundant proteins. Discovery of novel cancer biomarkers using proteomics is particularly challenging because specific biomarkers are expected to be low abundance proteins with normal blood concentrations of low nanograms per milliliter or less. Conventional, one- and two-dimensional proteomic methods including 2D PAGE, 2D DIGE, LC-MS/MS, and LC/LC-MS/MS do not have the capacity to consistently detect many proteins in this range. In contrast, new higher dimensional (Hi-D) separation strategies, utilizing more than two dimensions of fractionation, can profile the low abundance proteome.

B and T cells in the brains of autoimmune mice

Systemic lupus erythematosus (SLE) is an autoimmune disorder that can involve the central nervous system (CNS). Recently, we reported the presence of autoantibodies bound to the brain tissue of murine models of lupus; MRL/lpr and BXSB. We postulated that the source of these autoantibodies was in part due to in situ production, caused by the entry of B and T cells. Frozen brain sections of MRL/lpr and BXSB at 1 and 4 months of age were stained for CD3 (T cells) and CD19 (B cells) markers using an immunofluorescent antibody binding assay. Confocal fluorescence microscopy showed both CD3(+) and CD19(+) cells at 4 months of age only in MRL/lpr mice. There were no lymphocytes seen in the other autoimmune model, BXSB. Results suggest a difference in the mechanisms by which autoantibodies access the brain in these two autoimmune models of lupus.

Immunoglobulin binding to brain in autoimmune mice

Brain-reactive autoantibodies (BRAA) are thought to play an important role in central nervous system (CNS) manifestations of systemic lupus erythematosus (SLE). Previous studies have shown the existence of BRAA in human and murine SLE. This study was undertaken to establish and characterize the presence of autoantibody binding to brain of autoimmune mice. Laser confocal microscopy was performed on frozen brain sections to detect the presence of immunoglobulin (Ig) in the brain of MRL/lpr and BXSB mice and compare that to control strains of MRL/mp and C57BL/6 mice. There was a dramatic increase in fluorescence in the brains of MRL/lpr and BXSB at 4 months of age. There was little or no Ig detected in the brains of control mice. This increase in presence of Ig in the autoimmune mouse brain was paralleled by an increase in the serum titers of BRAA and anti-DNA autoantibodies as determined by ELISA. These studies provide another link between the existence of brain-reactive autoantibodies and altered CNS functioning.

Silver ion microplates for immunoassays

Microplate wells can be coated with silver ions using glutaraldehyde as a spacer molecule and thiourea as a complexing ligand. Microwells containing surface silver ions are shown to immobilize biotin-labeled horseradish peroxidase (HRP) in active form, while showing very little affinity for the unlabeled enzyme. These plates can also immobilize biotin-labeled antibodies that exhibit bioactivity after immobilization. Silver ions are needed for the complexation of the biotinylated enzyme or antibody because microwells modified to contain surface amine or thiourea molecules do not immobilize appreciable amounts of the labeled proteins. A maximum surface coverage for biotin-labeled HRP of 40 ng/cm2 and an immobilization binding constant of Km = 8 x 10(9)/M are determined from serial dilutions in a microplate. Detection of as little as 6.7 fmol HRP is achieved using antibodies immobilized on the silver ion-modified microplates. Active antibody surface densities were estimated to be between 130 and 260 nm2/antibody molecule. Background binding of HRP to the modified silver ion microplates was very low, allowing for reasonably accurate detection between 10(-14) and 10(-11) mol HRP.

A comparison of silver ion to streptavidin coated microplates

Direct comparisons are made between covalently linked streptavidin and silver ion coated microplates. Both coatings can immobilize biotinylated molecules. Silver ion coated microplate wells can immobilize 1.8 times higher amounts of biotin labeled horseradish peroxidase. The quantitation range and capacity for the capture of horseradish peroxidase using biotin labeled horseradish peroxidase are also greater for silver ion coated microplates. Approximately twice as many anti-horseradish peroxidase antibodies can be immobilized per well using silver ion coated microplates. Higher capacities are presumed to be due to the smaller footprint of silver ions as compared to streptavidin. A direct comparison between the two coatings for a beta-galactosidase ELISA showed that while the silver ion coated microplates gave higher readings, the streptavidin coated microplates exhibited smaller well-to-well variation. However, higher well to well variation for the silver microplates is attributed to the high density of anti-beta-galactosidase antibodies on the microplates and the weak binding of clone GAL-13 to beta-galactosidase, rather than the silver coating. These studies suggest silver ion coated microplates are a desirable alternative to streptavidin plates for quantitative immunoassays.

The immune system can affect learning: chronic immune complex disease in a rat model

Evidence is presented that the immune system can affect central nervous system functioning, leading to changes in learning. Immune complex disease is induced in rats and their behavior tested using a Lashley maze. Significant differences in behavior were found between the animals with high disease activity and those with low disease activity and the non-disease controls. These changes were not due to uremia and are most likely due to the immune response. There is some evidence immune complex deposits in the choroid plexus may play some role, but not the sole or major role in the behavioral changes. This provides a model by which immunologic processes can cause neuropsychiatric manifestations in autoimmune diseases like lupus, as well as showing that immune processes can affect behavioral functioning.

Characterization of murine brain-reactive monoclonal IgG autoantibodies

A diversity of brain-reactive autoantibodies (BRAA) is found in the sera and cerebrospinal fluid in elevated amounts in systemic lupus erythematosus (SLE) and correlates with some CNS manifestations of both human and murine SLE. In order to test the hypothesis that BRAA mediate the CNA manifestations, we are developing a library of brain-reactive monoclonal autoantibodies (BRMA) from autoimmune mice for characterization. We have recently reported on the production of BRMA of the IgM class from unimmunized autoimmune mice. In the current study we extend our investigations and report on the production and characterization of two BRMA of the IgG class. These antibodies react against integral brain membrane antigens of approximately 58, 32, and 30 kDa by immunoblot. Reactivity to such antigens is also found in a majority of the autoimmune murine serum samples tested, but not in nonautoimmune mice. These IgG BRMA show reactivity to cell bodies of the cerebral cortex, hippocampus, and hypothalamus of murine brain but not to fiber tracts. They also react with an integral thymus membrane antigen, but not to antigens of other tissues tested. Because of their properties, BRMA such as those characterized here are likely to be of pathogenic significance in CNS involvement in SLE.

Nanometer spatial resolution achieved in hard x-ray imaging and Laue diffraction experiments

Tapered glass capillaries have successfully condensed hard x-ray beams to ultrasmall dimensions providing unprecedented spatial resolution for the characterization of materials. A spatial resolution of 50 nanometers was obtained while imaging a lithographically prepared gold pattern with x-rays in the energy range of 5 to 8 kiloelectron volts. This is the highest resolution scanning x-ray image made to date with hard x-rays. With a beam 360 nanometers in diameter, Laue diffraction was observed from the smallest sample volume ever probed by x-ray diffraction, 5 x 10(-3) cubic micrometers.

Effects of peripheral cytokine injections on multiple unit activity in the anterior hypothalamic area of the mouse

The brain and the immune system interact in a bidirectional manner. This study on neuroimmune circuitry investigated the hypothesis that circulating cytokines act as messengers in the communication from the immune system to the brain and that the anterior hypothalamus is an integral part of this pathway. It was predicted that, following tail vein injections in mice, the cytokines interleukin-1 beta (IL-1 beta), interleukin-2 (IL-2), and interleukin-6 (IL-6) would alter electrical activity in the anterior hypothalamus. Differential electrodes were used to record multiple unit activity, at 5-min intervals, immediately before and for 60 min following injections. IL-1 beta and IL-2 decreased activity in the lateral margin of the anterior hypothalamus. IL-2-responsive neurons seemed to be localized to this area, while IL-1 beta-sensitive neurons showed a larger area of distribution. A significant response following IL-6 administration was not demonstrated. The observed changes in electrical activity support the concept of the hypothalamus as a sensory integration site for the immune system. Alternative models for the mechanism of cytokine signaling are discussed.

Anti-brain antibodies in the sera of rheumatoid arthritis patients: relation to disease activity and psychological status

Auto-antibodies reactive with brain are known to occur in various immunological disorders. Their significance with respect to disease activity, neurological manifestations, or psychological status is, however, not known. In previous studies it was found that there were antibodies reactive with brain in the sera of patients with rheumatoid arthritis (RA). The present study sought to confirm and extend our previous findings and determine the significance of these antibodies with respect to disease activity. It also investigated a possible connection between psychological function in RA and these auto-antibodies. Sera drawn from 14 RA patients, at bi-weekly intervals over 3 months, showed the presence of antibodies against transmembrane proteins from murine brain. These antibodies correlated positively with rheumatoid factor and joint swelling. There was a trend toward a correlation between depression and daily mood scores and the number of antibodies reactive with brain. In addition, a correlation between cognitive coping styles in RA patients and auto-antibodies was found. There was also evidence for a sub-population of pathogenic antibodies.

Brain reactive monoclonal auto-antibodies: production and characterization

To determine the role of auto-antibodies in the pathogenesis of neuropsychiatric manifestations of systemic lupus erythematosus (NP-SLE), it will be necessary to characterize the diversity of auto-antibodies that exist. This can be done by producing a library of monoclonal, brain-reactive auto-antibodies. From such a library the antigens to which the antibodies bind, and whether there are any interesting relations between these antigens, can be determined. Behavioral effects can also be investigated. Toward these ends, brain-reactive monoclonal auto-antibodies (BRMA) were produced. The production and characterization of two monoclonal antibodies is presented in this study.

Detection of brain-reactive autoantibodies in the sera of autoimmune mice using ELISA

There are considerable problems with developing an assay to detect the often small quantities of autoantibodies which react against antigens in a heterogeneous and complex mixture from a source such as brain. An indirect enzyme-linked immunosorbent assay (ELISA) has been developed which can detect naturally occurring autoantibodies in serum that are reactive with integral brain membrane antigens. Sera were collected from autoimmune BXSB and NZB mice and non-autoimmune C57BL/6 mice at various ages and were assayed for the presence of brain-reactive autoantibodies (BRAAs). It is shown that this technique provides a highly sensitive, specific, and rapid assay for detecting BRAAs in serum. It shows that integral membrane antigens from whole brain can be isolated and used to detect and quantitate antibodies in the sera of autoimmune and non-autoimmune mice. The data also confirm studies, using different techniques, showing higher levels of autoantibodies to brain in autoimmune as compared to non-autoimmune mice. There are numerous potential applications for this ELISA, such as in rapidly screening large numbers of samples of biological fluids, tracking autoimmune disease progression over time, detecting small quantities of antibody against brain antigens, and as an assay system for investigating the role of BRAAs in the pathogenesis of immune mediated CNS disease.

Brain specific autoantibodies in murine models of systemic lupus erythematosus

Autoantibodies which bind to integral membrane proteins of brain were tested for their ability to bind to cross-reactive antigens on non-neural tissue. Both brain specific autoantibodies and antibodies which bind to cross-reactive antigens were found. There were two types of brain reactive autoantibodies which could not be adsorbed by non-neural tissue. One type was adsorbable by crude cell membrane preparations of brain. The second type was reactive against integral membrane proteins of brain, but not adsorbable by any of the crude membrane preparations tested. Autoantibodies of the first type reacted against integral membrane proteins with apparent molecular weights of 75, 70, 62, 50, 27, 24 and 20 kDa, as determined by gel electrophoresis and immunoblotting. As in previous studies, a diversity of brain reactive autoantibodies were found. The greatest numbers and strongest banding patterns were seen in the autoimmune strains of mice. The non-autoimmune strain displayed these autoantibodies at much lower levels. These results are the first to find brain specific autoantibodies, from autoimmune mice, against integral brain membrane antigens. The data support the idea that there is a sub-population of brain reactive autoantibodies which are involved in the pathogenesis of neuropsychiatric manifestations in immunologic disorders, particularly systemic lupus erythematosus.

Characterization of brain-reactive autoantibodies in murine models of systemic lupus erythematosus

Using the Western blot technique we analyzed the sera of five strains of mice that develop a disease like systemic lupus erythematosus (SLE), along with two normal strains, for their binding specificities against isolated mouse integral brain membrane proteins. This report describes the distribution and frequency of the more than 200 brain-reactive autoantibodies in the 126 animals tested and verifies the hypothesis of diversity in anti-brain antibodies produced during autoimmune conditions such as SLE. These results emphasize the importance of characterizing the brain-reactive autoantibodies in the sera or cerebrospinal fluid of SLE patients with central nervous system involvement.

Identification of autoantibody reactive integral brain membrane antigens. A two-dimensional analysis

A procedure to identify murine autoantibody reactive, integral membrane antigens of brain is described. This involved the isolation of integral membrane antigens from whole brain followed by two-dimensional (2D) gel electrophoretic separation and transfer to nitrocellulose (NC) membrane. A 2D 'map' was then constructed by an effective total protein staining procedure. This 'map' was subsequently compared with similar blots that were reacted with autoimmune sera, stained for immunoglobulin and the reactive antigens identified. Advantages of this procedure include economy in the reagents and sera used, not having to use radioactive substances and much shorter working time. This technique will permit the identification of brain reactive autoantibodies.

Characterization of cell surface antigens on the adrenergic neuroblastoma clone A2(1)

Neuroblastoma cell lines have been extensively used to identify the presence of brain reactive autoantibodies in the sera of patients with systemic lupus erythematosus (SLE) who have neuropsychiatric involvement and in the animal models (murine) of this disorder. In this study, a characterization of murine neuroblastoma cell surface antigens, from the adrenergic A2(1) cell line, have indicated both similarities and differences with the cell surface antigens of normal mouse brain. It has also shown that some of these antigens are nervous system specific, whereas others are not. These data indicate that a more precise definition of the antigens on the surface of neuroblastoma cells, with which anti-brain autoantibodies react, is necessary for an understanding of the neuropsychiatric manifestations associated with autoimmune diseases such as SLE.

Brain-reactive autoantibody levels in the sera of ageing autoimmune mice

Brain-reactive autoantibodies are thought to play an important role in mediating central nervous system (CNS) disorders in systemic lupus erythematosus (SLE). In this paper the developmental occurrence of these antibodies in the sera of autoimmune mice, i.e. NZB, NZB/W, MRL/l and BXSB mice were examined. All murine strains tested, whether autoimmune or not, showed some degree of serum reactivity toward brain antigens. Autoimmune mice, however, displayed higher levels of serum brain-reactive antibodies, and at earlier ages, than non-autoimmune mice. Immunofluorescence assays against brain sections and adsorption assays, with both neural and non-neural tissue, indicated a heterogeneity in the specificity of the populations of brain-reactive antibodies present. These studies provide an important step in characterizing the appearance and diversity of brain-reactive autoantibodies, with the goal of better understanding their significance and potential role in mediating CNS dysfunction in SLE.

Permeability of the blood cerebrospinal fluid barrier during acute immune complex disease

Changes in the permeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid (blood-CSF) barrier in rabbits were assessed by using a sensitive double isotope technique at different times after the induction of acute immune complex disease (AICD). Induction of AICD was done with a single large dose of bovine serum albumin, whereas controls received only saline. Animals were sacrificed 6, 9, 12, 15, and 18 days after induction. Extravasation of protein was measured by injecting rabbits i.v. with 131I-rabbit serum albumin (RSA) 24 hr before sacrifice. In order to correct for intravascular blood volume, 125I-RSA was injected 5 min before sacrifice. Extravascular blood equivalents (EVBE), a measure of barrier permeability, were elevated in the CSF of rabbits sacrificed on days 12 and 15. None of the brain regions from any of the animal groups showed any changes or significant differences from controls in EVBE values on these days. These results indicate that there was an increase in the permeability of the blood-CSF barrier to radiolabeled albumin but not in the BBB proper during the time that CSF IgG levels were elevated in AICD. The potential significance of these findings for the mechanisms mediating central nervous system involvement in systemic lupus erythematosus is discussed.

Permeability of the blood cerebrospinal fluid barrier during acute immune complex disease

Changes in the permeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid (blood-CSF) barrier in rabbits were assessed by using a sensitive double isotope technique at different times after the induction of acute immune complex disease (AICD). Induction of AICD was done with a single large dose of bovine serum albumin, whereas controls received only saline. Animals were sacrificed 6, 9, 12, 15, and 18 days after induction. Extravasation of protein was measured by injecting rabbits i.v. with 131I-rabbit serum albumin (RSA) 24 hr before sacrifice. In order to correct for intravascular blood volume, 125I-RSA was injected 5 min before sacrifice. Extravascular blood equivalents (EVBE), a measure of barrier permeability, were elevated in the CSF of rabbits sacrificed on days 12 and 15. None of the brain regions from any of the animal groups showed any changes or significant differences from controls in EVBE values on these days. These results indicate that there was an increase in the permeability of the blood-CSF barrier to radiolabeled albumin but not in the BBB proper during the time that CSF IgG levels were elevated in AICD. The potential significance of these findings for the mechanisms mediating central nervous system involvement in systemic lupus erythematosus is discussed.

Prostatic acid phosphatase and sperm in the post-coital vagina

Sperm and prostatic acid phosphatase identified in vaginal fluid after an alleged sexual assault constitute important physical evidence useful in courts of law during rape trials. The purpose of this study was to define a normal and abnormal range for acid phosphatase in the post-coital vagina for our emergency department and to compare the sensitivity of acid phosphatase versus sperm in determining recent coitus. Vaginal swabs obtained from 90 patients were analyzed for acid phosphatase activity by the Sigma p-nitrophenyl phosphate technique. Swabs were stored in a bovine albumin preservative broth. Pap smears for sperm identification were also performed. Acid phosphatase values greater than 50, especially those greater than 138 Sigma units/cc, correlated with intercourse within the preceding 24 hours (P .005). Values greater than 20 but less than 50 correlated with intercourse within 48 hours (P .005). The presence or absence of sperm was found to be less sensitive, and correlated poorly with the time since intercourse [of 12 cases less than or equal to 24 hours, 11 were acid phosphatase-positive (91.7%) while seven were sperm-positive (58.4%)].

Suppression of water intake by immune complex formation in the hypothalamus. Implications for systemic lupus erythematosus

Immune complex formation in the perifornical region of the hypothalamus resulted in depressed water consumption in rats, but did not consistently alter body temperature. The antibody with an unrelated antigen did not affect water consumption or body temperature. These results support the notion that immune complex reactions within the central nervous system can alter behavior.

Ethanol-induced hypoglycemic coma in a child

Reported is a case of ethanol-induced hypoglycemic coma in a 33-month-old boy after accidental ingestion of ethanol. Blood glucose was 10 mg% and blood ethanol was 71 mg%. He responded promptly to an IV bolus of 50% dextrose. The pathophysiology and clinical presentation of this not uncommon metabolic disorder are discussed. A plan for early recognition and management is presented.

Simple apparatus for blocking small animal brains

A modification of previously described devices for blocking small animal brains is presented. The apparatus is easily constructed and allows for blocking at varous angles of both fixed and unfixed tissue of most small laboratory animals.

Chronic immune complex disease: behavioral and immunological correlates

Using a fear avoidance paradigm, behavioral effects were seen in Sprague-Dawley rats in which chronic immune complex disease was induced. These effects were related to changes in urine protein that developed during the course of the experiment. Experimental animals also had glomerular deposits of rat gamma globulin and BSA as determined by immunofluorescence; C3 deposits were observed in half of these animals. BSA and/or rat gamma-globulin, but not C3, was seen in the choroid plexus of half of the experimental animals. This is the first study to report behavioral changes associated with the induction of chronic immune complex disease in experimental animals.

A naturally occurring antibody in New Zealand mice cytotoxic to dissociated cerebellar cells

A spontaneously occurring antibody cytotoxic to dissociated cells of the neonate mouse cerebellum was found in the sera of some New Zealand (NZ) mice. No significant activity was found in the sera of six non-autoimmune mouse strains. The degree of cytotoxicity was similar towards both allogeneic and syngeneic cells. Absorption of the cytotoxic sera with brain and kidney homogenates removed the reactivity, while liver removed less reactivity. Absorptions with thymocytes and several other tissue homogenates and cells had no effect on the cytotoxicity levels, nor was there a correlation between the levels of thymocytotoxicity and cerebellar cell cytotoxicity. The antibody cytotoxic for cerebellar cells could not be demonstrated in the cerebrospinal fluid (CSF) of any mice examined, including a mouse with high serum cytotoxic levels. Gel filtration of reactive sera indicated that the antibody is of the IgM class.