Developing a Prospective Gestational Lyme Disease Study

Lyme disease in pregnancy is understudied. The few available reports of Borrelia infection during pregnancy collecting clinical outcomes, with or without confirmed fetal infection both in utero and neonatal, are limited to case reports and small series. Population-based studies are not available. We propose a prospective study of Borrelia infection during pregnancy based in obstetrical practices in both endemic and nonendemic areas, with long term follow-up of pregnancy outcomes and development assessment of offspring infected or exposed to Borrelia in utero using current serological, microscopic, culture, and molecular techniques. In addition to detection of Borrelia burgdorferi sensu stricto, additional Borrelia species and other pathogens known to be transmitted by ticks will be tested. Serial biospecimens including maternal and cord blood, maternal peripheral blood mononuclear cells and urine, and, when clinically indicated, amniotic fluid, chorionic villi, intrauterine cord blood, will be collected with clinical data, imaging, and for infections treatment medications. Offspring will be followed until age 5 years with annual developmental assessments to assess pregnancy outcomes. The study will require parallel development of a biorepository with strategies for management, data security and data sharing. A public-private partnership will be required to support the study.

Establishing a Pregnancy Lyme Disease Biobank

Availability of relevant biological samples supports both basic science research and patient-centered clinical studies. Establishing a biorepository faces challenges at multiple levels. These tasks include defining mission definition and scope; selection of subjects and sample types; recruitment strategies; timing of collection in the patient's journey; sample logistics and processing; determining what clinical data to collect; ensuring sample integrity on transport, processing, and storage; defining governance structures and oversight responsibilities; clarifying sample provenance and ownership; establishing procedures for sample and data access; selecting testing to be performed routinely versus upon request, and management of results; data security; funding sources; and regulatory compliance. Establishing and maintaining a biorepository therefore requires careful planning, diligent and sustained execution, technical and financial resources, stakeholder support, and flexible and resilient management to respond to changing environments and needs.

Dr. Naides replies

We thank Dr. Russell for raising the issue of reporting the false positivity rate of antinuclear antibody (ANA) indirect immunofluorescent assay (IFA) testing.1 It is difficult, however, for a laboratory to state a false positive rate, per se, as the determination of “falseness” is dependent on clinical evaluation that is typically not available to most laboratories.

Highlights of the 33rd annual scientific meeting of the Association of Medical Laboratory Immunologists (AMLI)

The annual meeting of the Association of Medical Laboratory Immunologists (AMLI) was convened virtually over the month of August. Prior to the emergence of the COVID-19 pandemic, AMLI's scientific committee had chosen the following topics as the focus of its 2020 meeting: Histocompatibility Testing and Transplant Immunology; Secondary Immunodeficiency and Immunotherapy Monitoring; ANA Update; and Emerging Infectious Diseases and New Algorithms for Testing. Given the central role of the discipline in the evaluation of the host response to infection, it was apt to add a separate session on antibody testing for SARS-CoV-2 infections to the original program. The current report provides an overview of the subjects discussed in the course of this meeting.

Prevalence and significance of serum 14-3-3η in juvenile idiopathic arthritis

BACKGROUND

Prompt diagnosis of juvenile idiopathic arthritis (JIA) is important to avoid long term complications. Elevated serum 14-3-3η levels improve the diagnostic sensitivity of rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibody in adult rheumatoid arthritis (RA), and have been associated with more severe phenotype. We investigated the prevalence and clinical significance of serum 14-3-3η in different types of JIA.

METHODS

JIA patients (n = 151) followed by the Pediatric Rheumatology Core at Children's Hospital of Los Angeles were categorized into 5 groups: polyarticular JIA RF+ (PJIA RF+; n = 39), PJIA RF- (n = 39), psoriatic arthritis (PsA; n = 19), enthesitis-related arthritis (ERA; n = 18), and oligoarticular JIA (OJIA [control group]; n = 36). RF, CCP antibody, and 14-3-3η were measured for all patients. 14-3-3η serum levels > 0.2 ng/mL were considered positive. Disease activity was assessed by the Juvenile Arthritis Disease Activity Score-71 (JADAS-71).

RESULTS

Elevated 14-3-3η levels were detected in 34/151 (23%) patients, and across all groups tested. Most patients with 14-3-3η had titers ≥4 times above the cutoff value. The majority (22, 65%) of 14-3-3η-positive patients were also positive for RF or CCP antibodies, 16 (47%) were positive for all 3, and 12 (35%) were single-positive for 14-3-3η. The highest prevalence of 14-3-3η was in PJIA RF+ patients (49%), followed by OJIA (22%). Positivity for 14-3-3η was not significantly associated with disease activity or age at diagnosis.

CONCLUSION

Serum 14-3-3η can be detected in all forms of JIA tested but appears to be most common in PJIA RF+. 14-3-3η does not appear to correlate with disease activity in JIA.

The Development of New Diagnostic Tests for Neurologic Disorders in the Commercial Laboratory Environment

Development of new diagnostic tests in a commercial laboratory for neurologic disorders is challenging. Development occurs in a highly regulated environment. Relevant research infrastructure may not be readily available in-house and may require outsourcing with additional management and costs. Clinically characterized specimens for validation of biomarkers for esoteric diseases may be difficult to acquire, and market size may be difficult to predict. More common diseases with heterogeneous subsets may require better clinical definition. Absence of guidelines may delay health provider acceptance of novel testing. Regulatory agency approval and categorization of tests affects validation requirements and impacts market acceptance and reimbursement.

The rapid Bethesda assay is equivalent to the standard Bethesda assay for detection of factor IX inhibitors in patients with severe haemophilia B

INTRODUCTION

The time-dependent nature of factor VIII (FVIII) inhibitors is well described, and the standard FVIII Bethesda assay used to measure inhibitors incorporates a 2-hour incubation. Despite case reports and reviews describing the immediate-acting nature of factor IX (FIX) inhibitors, many coagulation laboratories continue to use a traditional prolonged incubation for FIX Bethesda assays. To our knowledge, a comprehensive evaluation of the FIX Bethesda assay without incubation has not been reported.

AIM

The goal of this study was to evaluate the performance of a rapid FIX Bethesda (ie no incubation) compared with the standard Bethesda assay (2-hour incubation).

METHODS

The analysis used a Bethesda assay configured for either immediate testing or a 2-hour incubation. Samples from 14 haemophilia B patients with inhibitors and 9 non-human controls were tested.

RESULTS

The two assays yielded similar performance overall. The average per cent difference in inhibitor titre between the rapid and standard FIX Bethesda assay was -3% (range -15% to +13%; P = .175) for patient samples and -2% (range -17% to +14%; P = .376) for controls.

CONCLUSION

The rapid Bethesda assay showed good agreement with the standard Bethesda assay for determination of inhibitor levels in patients with severe haemophilia B. The rapid assay allows for faster assessment of inhibitors in patients with severe haemophilia B and has the potential to improve the ability of the coagulation laboratory to perform testing from a logistical viewpoint. Further studies involving larger numbers of patients would be important to confirm our findings.

Antinuclear Antibodies Testing Method Variability: A Survey of Participants in the College of American Pathologists' Proficiency Testing Program

OBJECTIVE

This study was conducted to determine the spectrum of laboratory practices in antinuclear antibody (ANA) test target, performance, and result reporting.

METHODS

A questionnaire on ANA testing was distributed by the Diagnostic Immunology and Flow Cytometry Committee of the College of American Pathologists (CAP) to laboratories participating in the 2016 CAP ANA proficiency survey.

RESULTS

Of 5847 survey kits distributed, 1206 (21%) responded. ANA screening method varied: 55% indirect immunofluorescence assay, 21% ELISA, 12% multibead immunoassay, and 18% other methods. The name of the test indicated the method used in only 32% of laboratories; only 39% stated the method used on the report. Of 644 laboratories, 80% used HEp-2 cell substrate, 18% HEp-2000 (HEp-2 cell line engineered to overexpress SSA antigen, Ro60), and 2% other. Slides were prepared manually (67%) or on an automated platform (33%) and examined by direct microscopy (84%) or images captured by an automated platform (16%). Only 50% reported a positive result at the customary 1:40 dilution. Titer was reported to endpoint routinely by 43%, only upon request by 23%, or never by 35%. Of the laboratories, 8% did not report dual patterns. Of those reporting multiple patterns, 23% did not report a titer with each pattern.

CONCLUSION

ANA methodology and practice, and test naming and reporting varies significantly between laboratories. Lack of uniformity in testing and reporting practice and lack of transparency in communicating the testing method may misdirect clinicians in their management of patients.

Parvovirus B19V Nonstructural Protein NS1 Induces Double-Stranded Deoxyribonucleic Acid Autoantibodies and End-Organ Damage in Nonautoimmune Mice

Background

Viral infection is implicated in development of autoimmunity. Parvovirus B19 (B19V) nonstructural protein, NS1, a helicase, covalently modifies self double-stranded deoxyribonucleic acid (dsDNA) and induces apoptosis. This study tested whether resulting apoptotic bodies (ApoBods) containing virally modified dsDNA could induce autoimmunity in an animal model.

Methods

BALB/c mice were inoculated with (1) pristane-induced, (2) B19V NS1-induced, or (3) staurosporine-induced ApoBods. Serum was tested for dsDNA autoantibodies by Crithidia luciliae staining and enzyme-linked immunosorbent assay. Brain, heart, liver, and kidney pathology was examined. Deposition of self-antigens in glomeruli was examined by staining with antibodies to dsDNA, histones H1 and H4, and TATA-binding protein.

Results

The B19V NS1-induced ApoBod inoculation induced dsDNA autoantibodies in a dose-dependent fashion. Histopathological features of immune-mediated organ damage were evident in pristane-induced and NS1-induced ApoBod groups; severity scores were higher in these groups than in staurosporine-treated groups. Tissue damage was dependent on NS1-induced ApoBod dose. Nucleosomal antigens were deposited in target tissue from pristane-induced and NS1-induced ApoBod inoculated groups, but not in the staurosporine-induced ApoBod inoculated group.

Conclusions

This study demonstrated proof of principle in an animal model that virally modified dsDNA in apoptotic bodies could break tolerance to self dsDNA and induce dsDNA autoantibodies and end-organ damage.

Reference intervals for lymphocyte subsets in preterm and term neonates without immune defects

BACKGROUND

In 6.5 years of newborn screening for severe combined immunodeficiency in California, 3,252,156 infants had DNA from dried blood spots (DBSs) assayed for T-cell receptor excision circles. Infants with T-cell receptor excision circle values of less than a designated cutoff on a single DBS, 2 DBS samples with insufficient PCR amplification, or known genetic risk of immunodeficiency had peripheral blood complete blood counts and lymphocyte subsets assayed in a single flow cytometry laboratory. Cases in which immune defects were ruled out were available for analysis.

OBJECTIVE

We sought to determine reference intervals for lymphocyte subsets in racially/ethnically diverse preterm and term newborns who proved to be unaffected by any T-lymphopenic immune disorder.

METHODS

Effective gestational age (GA) was defined as GA at birth plus postnatal age at the time of sample collection. After determining exclusion criteria, we analyzed demographic and clinical information, complete and differential white blood cell counts, and lymphocyte subsets for 301 infants, with serial measurements for 33 infants. Lymphocyte subset measurements included total T cells, helper and cytotoxic T-cell subsets, naive and memory phenotype of each T-cell subset, B cells, and natural killer cells.

RESULTS

Reference intervals were generated for absolute numbers and lymphocyte subsets from infants with effective GAs of 22 to 52 weeks. Sex and ethnicity were not significant determinants of lymphocyte subset counts in this population. Lymphocyte counts increased postnatally.

CONCLUSION

This study provides a baseline for interpreting comprehensive lymphocyte data in preterm and term infants, aiding clinicians to determine which newborns require further evaluations for immunodeficiency.

Newborn Screening for Severe Combined Immunodeficiency and T-cell Lymphopenia in California, 2010-2017

OBJECTIVES

Newborn screening for severe combined immunodeficiency (SCID) was instituted in California in 2010. In the ensuing 6.5 years, 3 252 156 infants in the state had DNA from dried blood spots assayed for T-cell receptor excision circles (TRECs). Abnormal TREC results were followed-up with liquid blood testing for T-cell abnormalities. We report the performance of the SCID screening program and the outcomes of infants who were identified.

METHODS

Data that were reviewed and analyzed included demographics, nursery summaries, TREC and lymphocyte flow-cytometry values, and available follow-up, including clinical and genetic diagnoses, treatments, and outcomes.

RESULTS

Infants with clinically significant T-cell lymphopenia (TCL) were successfully identified at a rate of 1 in 15 300 births. Of these, 50 cases of SCID, or 1 in 65 000 births (95% confidence interval 1 in 51 000-1 in 90 000) were found. Prompt treatment led to 94% survival. Infants with non-SCID TCL were also identified, diagnosed and managed, including 4 with complete DiGeorge syndrome who received thymus transplants. Although no cases of typical SCID are known to have been missed, 2 infants with delayed-onset leaky SCID had normal neonatal TREC screens but came to clinical attention at 7 and 23 months of age.

CONCLUSIONS

Population-based TREC testing, although unable to detect immune defects in which T cells are present at birth, is effective for identifying SCID and clinically important TCL with high sensitivity and specificity. The experience in California supports the rapid, widespread adoption of SCID newborn screening.

The role of the laboratory in the expanding field of neuroimmunology: Autoantibodies to neural targets

Accelerated identification of autoantibodies associated with previously idiopathic neurological disease has provided insights into disease mechanisms, enhanced understanding of neurological function, and opportunities for improved therapeutic interventions. The role of the laboratory in the expanding field of neuroimmunology is critical as specific autoantibody identification provides guidance to clinicians in diagnosis, prognosis, tumor search strategies, and therapeutic interventions. The number of specific autoantibodies identified continues to increase and newer testing strategies increase efficiencies in the laboratory and availability to clinicians. The need for broadly targeted efficient testing is underscored by the variability in clinical presentation and tumor associations attributable to a specific autoantibody, and conversely the various autoantibody specificities that can be the cause of a given clinical presentation. While many of the antineural antibodies were first recognized in the setting of neoplastic disease, idiopathic autoimmune neurological disease in the absence of underlying tumor is increasingly recognized. Appropriation of therapeutic modalities used to treat autoimmune disease to treat these autoantibody mediated neurological diseases has improved patient outcomes. Interaction between clinicians and laboratorians is critical to our understanding of these diseases and optimization of the clinical benefits of our increasing knowledge in neuroimmunology.

Infection Control Measures for Human Parvovirus Bl9 in the Hospital Setting

A human parvovirus was first discovered serendipitously in blood from asymptomatic donors in 1975' and designated B19 because of the location of the original positive serum in a test panel. Subsequently, the newly discovered virus was determined to be the etiologic agent of most cases of transient aplastic crisis in the setting of chronic hemolytic anemia and of the childhood exanthem erythema infectiosum, or fifth disease. While erythema infectiosum with its classic “slapped-cheek” rash is a childhood illness, “fifth disease” in the adult should not be overlooked. At least 40% of adults lack serological evidence of past human parvovirus B19 infection and are at risk. Adults tend to have a more subtle rash, often lacking the “slapped cheeks,” and tend to have a more severe constitutional, flu-like illness with prominent joint symptoms. While the arthralgia and arthritis of adult “fifth disease” are often self-limiting, they may become chronic and lead to an arthropathy that meets American College of Kheumatology criteria for a diagnosis of rheumatoid arthritis. The arthropathy has been reported to persist up to five years, the longest follow-up now available (A. Wolf; MD, personal communication, August 27, 1987).

Variability in Testing for Antineutrophil Cytoplasmic Antibodies: A Survey of Participants in the College of American Pathologists Proficiency Testing Program

CONTEXT

-Variability in testing for antineutrophil cytoplasmic antibodies (ANCAs) contributes to confusion and controversy related to testing for vasculitis and other ANCA-associated diseases.

OBJECTIVES

-To survey laboratory testing practices regarding ANCA testing and to investigate differences in testing algorithms.

DESIGN

-Supplemental questions were sent to the 333 laboratories participating in the College of American Pathologists proficiency testing program for ANCA as part of the Special Immunology S2 Survey.

RESULTS

-A total of 315 laboratories submitted responses to the supplemental questions. Only 88 of 315 participants (28%) reported using a combination of indirect immunofluorescence (IFA) and enzyme immunoassay (EIA) techniques as recommended by current guidelines, with a few additional labs using IFA and multiplex bead assay as an acceptable alternative to EIA. Other labs reported using only IFA, EIA, or multiplex bead assays.

CONCLUSIONS

-A wide variety of testing algorithms are in use for ANCA testing despite evidence to suggest that a combination of IFA and EIA testing provides the most comprehensive information. Laboratories should inform clinicians clearly about testing practices and utility of testing in specific disease states.

Newborn screening for severe combined immunodeficiency in 11 screening programs in the United States

IMPORTANCE

Newborn screening for severe combined immunodeficiency (SCID) using assays to detect T-cell receptor excision circles (TRECs) began in Wisconsin in 2008, and SCID was added to the national recommended uniform panel for newborn screened disorders in 2010. Currently 23 states, the District of Columbia, and the Navajo Nation conduct population-wide newborn screening for SCID. The incidence of SCID is estimated at 1 in 100,000 births.

OBJECTIVES

To present data from a spectrum of SCID newborn screening programs, establish population-based incidence for SCID and other conditions with T-cell lymphopenia, and document early institution of effective treatments.

DESIGN

Epidemiological and retrospective observational study.

SETTING

Representatives in states conducting SCID newborn screening were invited to submit their SCID screening algorithms, test performance data, and deidentified clinical and laboratory information regarding infants screened and cases with nonnormal results. Infants born from the start of each participating program from January 2008 through the most recent evaluable date prior to July 2013 were included. Representatives from 10 states plus the Navajo Area Indian Health Service contributed data from 3,030,083 newborns screened with a TREC test.

MAIN OUTCOMES AND MEASURES

Infants with SCID and other diagnoses of T-cell lymphopenia were classified. Incidence and, where possible, etiologies were determined. Interventions and survival were tracked.

RESULTS

Screening detected 52 cases of typical SCID, leaky SCID, and Omenn syndrome, affecting 1 in 58,000 infants (95% CI, 1/46,000-1/80,000). Survival of SCID-affected infants through their diagnosis and immune reconstitution was 87% (45/52), 92% (45/49) for infants who received transplantation, enzyme replacement, and/or gene therapy. Additional interventions for SCID and non-SCID T-cell lymphopenia included immunoglobulin infusions, preventive antibiotics, and avoidance of live vaccines. Variations in definitions and follow-up practices influenced the rates of detection of non-SCID T-cell lymphopenia.

CONCLUSIONS AND RELEVANCE

Newborn screening in 11 programs in the United States identified SCID in 1 in 58,000 infants, with high survival. The usefulness of detection of non-SCID T-cell lymphopenias by the same screening remains to be determined.

Serum 14-3-3η is a Novel Marker that Complements Current Serological Measurements to Enhance Detection of Patients with Rheumatoid Arthritis

Objective.

Serum 14-3-3η is a novel joint-derived proinflammatory mediator implicated in the pathogenesis of rheumatoid arthritis (RA). In our study, we assessed the diagnostic utility of 14-3-3η and its association with standard clinical and serological measures.

Methods.

A quantitative ELISA was used to assess 14-3-3η levels. Early (n = 99) and established patients with RA (n = 135) were compared to all controls (n = 385), including healthy subjects (n = 189). The sensitivity, specificity, positive and negative predictive values of 14-3-3η, and the likelihood ratios (LR) for RA were determined through receiver-operator curve analysis. The incremental value of adding 14-3-3η to anticitrullinated protein antibody (ACPA) and rheumatoid factor (RF) in diagnosing early and established RA was assessed.

Results.

Serum 14-3-3η differentiated established patients with RA from healthy individuals and all controls (p < 0.0001). A serum 14-3-3η cutoff of ≥ 0.19 ng/ml delivered a sensitivity and specificity of 77% and 93%, respectively, with corresponding LR positivity of 10.4. At this cutoff in early RA, 64% of patients with early RA were positive for 14-3-3η, with a corresponding specificity of 93% (LR+ of 8.6), while 59% and 57% were positive for ACPA or RF, respectively. When ACPA, RF, and 14-3-3η positivity were used in combination, 77 of the 99 patients (78%) with early RA were positive for any 1 of the 3 markers. Serum 14-3-3η did not correlate with C-reactive protein, erythrocyte sedimentation rate, or Disease Activity Score, but patients who were 14-3-3η-positive had significantly worse disease.

Conclusion.

Serum 14-3-3η is a novel RA mechanistic marker that is highly specific, associated with worse disease, and complements current markers, enabling a more accurate diagnosis of RA.

Human parvovirus B19 induced apoptotic bodies contain altered self-antigens that are phagocytosed by antigen presenting cells

Human parvovirus B19 (B19V) from the erythrovirus genus is known to be a pathogenic virus in humans. Prevalence of B19V infection has been reported worldwide in all seasons, with a high incidence in the spring. B19V is responsible for erythema infectiosum (fifth disease) commonly seen in children. Its other clinical presentations include arthralgia, arthritis, transient aplastic crisis, chronic anemia, congenital anemia, and hydrops fetalis. In addition, B19V infection has been reported to trigger autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. However, the mechanisms of B19V participation in autoimmunity are not fully understood. B19V induced chronic disease and persistent infection suggests B19V can serve as a model for viral host interactions and the role of viruses in the pathogenesis of autoimmune diseases. Here we investigate the involvement of B19V in the breakdown of immune tolerance. Previously, we demonstrated that the non-structural protein 1 (NS 1) of B19V induces apoptosis in non-permissive cells lines and that this protein can cleave host DNA as well as form NS1-DNA adducts. Here we provide evidence that through programmed cell death, apoptotic bodies (ApoBods) are generated by B19V NS1 expression in a non-permissive cell line. Characterization of purified ApoBods identified potential self-antigens within them. In particular, signature self-antigens such as Smith, ApoH, DNA, histone H4 and phosphatidylserine associated with autoimmunity were present in these ApoBods. In addition, when purified ApoBods were introduced to differentiated macrophages, recognition, engulfment and uptake occurred. This suggests that B19V can produce a source of self-antigens for immune cell processing. The results support our hypothesis that B19V NS1-DNA adducts, and nucleosomal and lysosomal antigens present in ApoBods created in non-permissive cell lines, are a source of self-antigens.

The putative metal coordination motif in the endonuclease domain of human Parvovirus B19 NS1 is critical for NS1 induced S phase arrest and DNA damage

The non-structural proteins (NS) of the parvovirus family are highly conserved multi-functional molecules that have been extensively characterized and shown to be integral to viral replication. Along with NTP-dependent helicase activity, these proteins carry within their sequences domains that allow them to bind DNA and act as nucleases in order to resolve the concatameric intermediates developed during viral replication. The parvovirus B19 NS1 protein contains sequence domains highly similar to those previously implicated in the above-described functions of NS proteins from adeno-associated virus (AAV), minute virus of mice (MVM) and other non-human parvoviruses. Previous studies have shown that transient transfection of B19 NS1 into human liver carcinoma (HepG2) cells initiates the intrinsic apoptotic cascade, ultimately resulting in cell death. In an effort to elucidate the mechanism of mammalian cell demise in the presence of B19 NS1, we undertook a mutagenesis analysis of the protein's endonuclease domain. Our studies have shown that, unlike wild-type NS1, which induces an accumulation of DNA damage, S phase arrest and apoptosis in HepG2 cells, disruptions in the metal coordination motif of the B19 NS1 protein reduce its ability to induce DNA damage and to trigger S phase arrest and subsequent apoptosis. These studies support our hypothesis that, in the absence of replicating B19 genomes, NS1-induced host cell DNA damage is responsible for apoptotic cell death observed in parvoviral infection of non-permissive mammalian cells.

Parvovirus B19 nonstructural protein-induced damage of cellular DNA and resultant apoptosis

Parvovirus B19 is a widespread virus with diverse clinical presentations. The viral nonstructural protein, NS1, binds to and cleaves the viral genome, and induces apoptosis when transfected into nonpermissive cells, such as hepatocytes. We hypothesized that the cytotoxicity of NS1 in such cells results from chromosomal DNA damage caused by the DNA-nicking and DNA-attaching activities of NS1. Upon testing this hypothesis, we found that NS1 covalently binds to cellular DNA and is modified by PARP, an enzyme involved in repairing single-stranded DNA nicks. We furthermore discovered that the DNA nick repair pathway initiated by poly(ADPribose)polymerase and the DNA repair pathways initiated by ATM/ATR are necessary for efficient apoptosis resulting from NS1 expression.

Parvovirus B19 genotype specific amino acid substitution in NS1 reduces the protein's cytotoxicity in culture

A clinical association between idiopathic liver disease and parvovirus B19 infection has been observed. Fulminant liver failure, not associated with other liver-tropic viruses, has been attributed to B19 in numerous reports, suggesting a possible role for B19 components in the extensive hepatocyte cytotoxicity observed in this condition. A recent report by Abe and colleagues (Int J Med Sci. 2007;4:105-9) demonstrated a link between persistent parvovirus B19 genotype I and III infection and fulminant liver failure. The genetic analysis of isolates obtained from these patients demonstrated a conservation of key amino acids in the nonstructural protein 1 (NS1) of the disease-associated genotypes. In this report we examine a conserved residue identified by Abe and colleagues and show that substitution of isoleucine 181 for methionine, as occurs in B19 genotype II, results in the reduction of B19 NS1-induced cytotoxicity of liver cells. Our results support the hypothesis that in the setting of persistent B19 infection, direct B19 NS1-induced cytotoxicity may play a role in idiopathic fulminant liver failure.

Musculoskeletal complaints and serum autoantibodies associated with chronic hepatitis C and nonalcoholic fatty liver disease

We sought to compare the musculoskeletal symptoms and immune markers found in chronic hepatitis C (HCV) and nonalcoholic fatty liver disease (NAFLD). Patients with HCV or NAFLD answered a questionnaire and donated serum for autoantibody testing. Univariate analysis between the HCV and NAFLD groups revealed joint pain in 67% of the HCV group and 65% of the NAFLD group. Those with joint pain reported inflammatory characteristics that were similar between the groups. The presence of a positive rheumatoid factor and cryoglobulins was higher in the HCV group, however both groups had a similar prevalence of a low positive antinuclear antibody (ANA). We conclude that the NAFLD group reported a higher amount of joint pain and inflammatory joint symptoms than anticipated. We were unable to determine a variable that predicted the presence of joint pain. Therefore, more investigation is needed to determine whether these findings are due to liver disease alone.

Ceramide recruits and activates protein kinase C zeta (PKC zeta) within structured membrane microdomains

We have previously demonstrated that hexanoyl-D-erythro-sphingosine (C(6)-ceramide), an anti-mitogenic cell-permeable lipid metabolite, limited vascular smooth muscle growth by abrogating trauma-induced Akt activity in a stretch injury model of neointimal hyperplasia. Furthermore, ceramide selectively and directly activated protein kinase C zeta (PKC zeta) to suppress Akt-dependent mitogenesis. To further analyze the interaction between ceramide and PKC zeta, the ability of ceramide to localize within highly structured lipid microdomains (rafts) and activate PKC zeta was investigated. Using rat aorta vascular smooth muscle cells (A7r5), we now demonstrate that C(6)-ceramide treatment results in an increased localization and phosphorylation of PKC zeta within caveolin-enriched lipid microdomians to inactivate Akt. In addition, ceramide specifically reduced the association of PKC zeta with 14-3-3, a scaffold protein localized to less structured regions within membranes. Pharmacological disruption of highly structured lipid microdomains resulted in abrogation of ceramide-activated, PKC zeta-dependent Akt inactivation, whereas molecular strategies suggest that ceramide-dependent PKC zeta phosphorylation of Akt3 at Ser(34) was necessary for ceramide-induced vascular smooth muscle cell growth arrest. Taken together, these data demonstrate that structured membrane microdomains are necessary for ceramide-induced activation of PKC zeta and resultant diminished Akt activity, leading to vascular smooth muscle cell growth arrest.

Apoptosis of liver-derived cells induced by parvovirus B19 nonstructural protein

Parvovirus B19 has been implicated in some cases of acute fulminant non-A, non-B, non-C, non-G liver failure. Our laboratory previously demonstrated that B19 infection of hepatocytes induces apoptosis and that the B19 viral nonstructural protein, NS1, may play a critical role. To study the involvement of NS1 in apoptosis of liver cells, we generated a fusion protein of NS1 with enhanced green fluorescent protein (eGFP) in a system allowing for inducible gene expression. Transfection of the liver-derived cell line HepG2 with the eGFP/NS1 vector allowed expression of the fusion protein, which was visualized by fluorescence microscopy and demonstrated by immunoblotting. The fusion protein localized to discrete domains in the nucleus. Transfection of HepG2 cells with the eGFP/NS1 vector led to apoptosis of 35% of transfected cells, a sevenfold increase over cells transfected with the parent eGFP expression vector. Mutation of the eGFP/NS1 vector to eliminate the nucleoside triphosphate-binding site of NS1 significantly decreased apoptosis, as did treatment of transfected cells with inhibitors of caspase 3 or 9. Neutralization of tumor necrosis factor alpha or Fas ligand had no effect on apoptosis. These results demonstrate that NS1 is sufficient to induce apoptosis in liver-derived cells and that it does so through the initiation of an intrinsic caspase pathway.

Viral Arthritis

The role of viruses in the development of acute and chronic arthritis is complex, because viruses are ubiquitous, and all human beings are occasionally afflicted by viral infections. In general, most viral infections are acute and self-limiting and survive by infecting one susceptible host, then moving on to another. Some viruses establish prolonged latency in the host after acute infection, whereas other agents produce chronic infections following the primary stage. The mechanisms whereby these infections produce arthritis are diverse and still poorly understood, but are clearly influenced by both host and viral factors. This review addresses these and other common forms of viral arthritis, such as that caused by parvovirus B19.

Parvovirus B19-induced apoptosis of hepatocytes

Parvovirus B19 (B19 virus) can persist in multiple tissues and has been implicated in a variety of diseases, including acute fulminant liver failure. The mechanism by which B19 virus induces liver failure remains unknown. Hepatocytes are nonpermissive for B19 virus replication. We previously reported that acute fulminant liver failure associated with B19 virus infection was characterized by hepatocellular dropout. We inoculated both primary hepatocytes and the hepatocellular carcinoma cell line Hep G2 with B19 virus and assayed for apoptosis by using annexin V staining. Reverse transcriptase PCR analysis and immunofluorescence demonstrated that B19 virus was able to infect the cells and produce its nonstructural protein but little or no structural capsid protein. Infection with B19 virus induced means of 28% of Hep G2 cells and 10% of primary hepatocytes to undergo apoptosis, which were four- and threefold increases, respectively, over background levels. Analysis of caspase involvement showed that B19 virus-inoculated cultures had a significant increase in the number of cells with active caspase 3. Inhibition studies demonstrated that caspases 3 and 9, but not caspase 8, are required for B19 virus-induced apoptosis.

Glycosphingolipid expression in acute nonlymphocytic leukemia: common expression of shiga toxin and parvovirus B19 receptors on early myeloblasts

Glycosphingolipids (GSLs) are complex macromolecules on cell membranes that have been shown to play a role in neutrophil differentiation, activation, phagocytosis, and adhesion to both microorganisms and vascular endothelium. Because GSLs are often cryptic antigens on cell membranes, little is known regarding GSL expression in early myelopoiesis. To study the latter, myeloblasts were collected from patients with acute nonlymphocytic leukemia (ANLL) who required therapeutic leukocytopheresis for hyperleukocytosis. The neutral GSLs were isolated and identified by high-performance thin-layer chromatography (HPTLC), HPTLC immunostaining, gas chromatography, nuclear magnetic resonance, and fast atom bombardment-mass spectrometry. Like mature peripheral blood neutrophils, myeloblasts expressed glucosylceramide, lactosylceramide, and the neolacto-family GSLs, lactotriaosylceramide and neolactotetraosylceramide. Unlike neutrophils and chronic myeloid leukemia, most ANLL samples also expressed the globo-series GSLs, globotriaosylceramide and globotetraosylceramide. Globo GSL expression was strongly associated with a myeloblastic (ANLL M0-M2) and monoblastic phenotype (M5). A weak association was also noted with expression of either lymphoid (P <.10) or early hematopoietic markers (terminal deoxynucleotidyl transferase [TdT], CD34; P <.10). Globo-positive ANLL samples bound both shiga toxin and parvovirus B19 on HPTLC immunostaining. Based on these findings, we propose that neolacto and globo GSLs are expressed during early myeloid differentiation. Globotriaosylceramide expression on myeloblasts, and possibly myeloid stem cells, may have important implications for the use of shiga toxin as an ex vivo purging agent in autologous stem cell transplantation. Expression of globotetraosylceramide, the parvovirus B19 receptor, on myeloblasts may also explain the association between B19 infection, aplastic anemia, and chronic neutropenia of childhood.

Induction of an invasive phenotype by human parvovirus B19 in normal human synovial fibroblasts

OBJECTIVE

To investigate the possible role of human parvovirus B19 as an etiologic agent in rheumatoid arthritis (RA), with particular emphasis on its ability to induce invasiveness in human synovial fibroblasts.

METHODS

We established an experimental in vitro system in which normal primary human synovial fibroblasts were treated with or without parvovirus B19-containing human sera for 7 days. The fibroblasts were then tested for their ability to degrade reconstituted cartilage matrix using a well-characterized cartilage invasion assay system.

RESULTS

Incubation with parvovirus B19-containing serum induced an invasive phenotype in normal human synovial fibroblasts. B19 serum-treated synovial fibroblasts exhibited an increase in invasion of up to 248% compared with the activity of fibroblasts in media alone, in contrast to B19-negative sera-treated synovial fibroblasts, which exhibited no significant change compared with that in media alone. In addition, preincubation of viremic serum with a neutralizing antibody to B19 abrogated the observed effect.

CONCLUSION

These results provide direct evidence regarding the ability of parvovirus B19 to induce invasive properties in normal human synovial fibroblasts. Parvovirus B19 has been proposed as an etiologic agent of RA, and our data provide the first biologic link between exposure to B19 and phenotypic changes in normal human synovial fibroblasts.

Human parvovirus B19 infection in acute fulminant liver failure

We previously reported detection of human parvovirus B19 DNA in livers from patients requiring transplantation for acute fulminant liver failure. In this study, we used immune adherence PCR (IA-PCR) to bind B19 virions in recipient native liver onto solid phase with specific monoclonal antibodies followed by PCR amplification of virion DNA. IA-PCR had sensitivity and specificity similar to conventional PCR. We examined liver tissue from 16 patients with non-A, non-B, non-C, non-E (NA-E) acute fulminant liver failure (AFLF) (6 of unknown etiology associated with aplastic anemia (AA), 4 of unknown etiology without AA; and 6 patients with AFLF of known etiology). IA-PCR detected B19 virions in 5 of 6 (83%) of livers from patients with idiopathic NA-E AFLF associated with AA and in 2 of 3 (75%) without AA, compared to 1 of 6 (17%) of livers from patients with AFLF of known etiology and to 6 of 34 (18%) of 34 control patients with chronic or neoplastic liver disease. Viral mRNA encoding the structural protein was detected in the liver tissue from three B19 IA-PCR positive patients with AFLF. Detection of B19 virions and mRNA for capsid proteins provided strong evidence for B19 infection during the course of NA-E AFLF and argues for involvement of B19 virus in liver injury.

Hepatitis E virus infection prevalence among selected populations in Iowa

BACKGROUND

HEV causes an enteric infectious disease endemic in developing areas with hot climate. A case of endogenous HEV infection has been reported in the US. Recently, HEV-like virus was isolated from swine in Iowa. Swine production is a major industry in Iowa with the potential for human exposure to swine in and around industrial and family farm operations.

OBJECTIVE

The study objective was to determine whether individuals in Iowa are exposed to HEV.

STUDY DESIGN

Anti-HEV antibody prevalence in four selected Iowa populations was determined. Sera were collected from 204 patients with non-A, non-B, non-C hepatitis (non-A-C); 87 staff members of the Department of Natural Resources (DRN); 332 volunteer blood donors in 1989; and 111 volunteer blood donors in 1998. All sera were tested for anti-human HEV IgM and IgG by ELISA with confirmation of positivity by a peptide neutralization test.

RESULTS

Both the patients with non-A, non-B, non-C hepatitis (4.9%) and the healthy field workers from the Iowa DNR (5.7%) showed significantly higher prevalence of anti-HEV IgG antibodies compared to normal blood donor sera collected in 1998 (P < 0.05).

CONCLUSIONS

Human HEV or a HEV-like agent circulates in the Iowa geographical area. At-risk human populations with occupational exposure to wild animals and environmental sources of domestic animal wastes or with unexplained hepatitis have increased seroprevalence of HEV antibodies.

Infection with Parvovirus B19

Human parvovirus B19 is common and widespread. Major manifestations of B19 infection are transient aplastic crisis, erythema infectiosum, hydrops fetalis, acute and chronic rheumatoid-like arthropathy and, in the immunocompromised host, chronic or recurrent bone marrow infection. Less common presentations include skin eruptions, isolated cytopenias, vasculitis, hepatitis, and neuropathies. Increasing awareness of the clinical manifestations of B19 infection makes parvovirus B19 an emerging virus. B19 may persist in healthy or immunocompromised individuals. B19 has been suggested as a candidate agent in rheumatic diseases.

Rheumatic manifestations of parvovirus B19 infection

Human parvovirus B19 is an emerging DNA virus. B19 infection is common and widespread. Major manifestations of B19 infection are transient aplastic crisis, erythema infectiosum, hydrops fetalis, acute and chronic rheumatoid-like arthropathy, and, in the immunocompromised host, chronic or recurrent bone marrow suppression. A number of less common manifestations of B19 infection include various rash illnesses, neuropathies, and acute fulminant liver failure. Of rheumatologic interest, B19 infection must be differentiated from early presentation of more classic erosive rheumatoid arthritis and, in some cases, systemic lupus erythematosus. It is unlikely that B19 plays a role in classic erosive rheumatoid arthritis, but understanding pathogenesis of B19 arthropathy may provide insights into the mechanisms by which rheumatoid arthritis develops. Evidence for persistence of B19 infection suggests that human parvovirus B19 infection may serve as a model for the study of virus-host interactions and the role of viruses in the pathogenesis of rheumatic diseases.

Transient blood plasmacytosis in parvovirus B19 infection: a report of two cases

Two patients with sickle cell disease were diagnosed with aplastic crisis caused by acute parvovirus B19 infection. One patient also developed thrombocytopenia associated with hemophagocytic histiocytosis in the bone marrow biopsy. Both patients developed transient blood plasmacytosis and hypocomplementemia soon after admission to the hospital. Transient blood plasmacytosis may be an immunological response to acute parvovirus B19 infection.

Parvovirus B19 as a possible causative agent of fulminant liver failure and associated aplastic anemia

We recently observed that more than one third of pediatric patients who presented with non-A, non-B fulminant liver failure (FLF) also developed aplastic anemia (AA) either before or shortly after liver transplantation. Factors involved in the suppression of bone marrow could be the same as those causing hepatic failure. We considered parvovirus B19 a candidate etiologic agent because of the known tropism of B19 for erythroid precursors. Archived liver and serum from six patients undergoing liver transplantation for non-A, non-B, non-C FLF with associated AA were analyzed for the presence of B19 DNA and anti-B19 serology. An age- and gender-matched control group (N = 44) was analyzed in parallel. B19 DNA studies and anti-B19 serology were performed in a blinded fashion. B19 serologies were performed by antibody capture enzyme-linked immunosorbent assay (ELISA). B19 DNA was detected after polymerase chain reaction (PCR) amplification of target B19 DNA sequences in liver and serum. Liver tissue showed evidence of B19 DNA in four of six (66%) patients with FLF and associated AA. Two of 4 patients with cryptogenic FLF but without AA had B19 DNA detected in the liver tissue. Of the 34 remaining controls, only 5 (15%) showed evidence of B19 DNA in liver tissue (66% vs. 15%, P = .016). B19 DNA was not detected in any of the test or control sera. This study provides evidence to support the role of parvovirus B19 in the development of FLF and associated AA.

Multiple glycosphingolipids determine the tissue tropism of parvovirus B19

Infection with human parvovirus B19, the etiologic agent of fifth disease, is associated with numerous hematologic and nonhematologic complications. Recently, the receptor for parvovirus B19 was reported to be globoside (Gb4), a neutral glycosphingolipid (GSL) of red cell membranes. To ascertain if tissue Gb4 expression correlates with B19-associated disease, neutral GSLs from 16 human tissues were isolated and analyzed using high-performance thin-layer chromatography and immunostaining with anti-Gb4 monoclonal antibodies or B19 empty capsids. Gb4 was identified as a major neutral GSL in 11 tissues, especially in those of mesodermal origin. In addition to recognizing Gb4, B19 capsid bound to several tissue-specific GSLs, including two complex globo series GSLs (SSEA-3, SSEA-4) and paragloboside (neolactotetraglycosylceramide), as was demonstrated in red cell, granulocyte, kidney, liver, and bowel tissue. There was good correlation between tissue-neutral GSL expression, B19 capsid binding, and the tissue tropism observed clinically in B19 parvovirus-associated disease.

Viral arthritis including HIV

Viruses are attractive candidates for infectious etiologic agents or cofactors in the development of rheumatic diseases. The epidemic of HIV infection and the recognition of "emerging viruses" continues to fuel interest in the possible role of viruses in the pathogenesis of diseases without defined etiologies. During 1994, roles for parvovirus B19 in vasculitis and erosive rheumatoid arthritis were entertained. We were reminded that rubella infection may present with polyarthritis. Our understanding of the rheumatic disease manifestations of hepatitis C virus infection was broadened to include polyarthritis. A possible role for herpesviruses in Sjögren's syndrome continued to be explored without definite resolution. Paramyxoviruses were offered as an agent in the development of Paget's disease. The retroviruses continued to attract attention because of rheumatic disease syndromes in AIDS patients and the ability of retroviruses to latently infect the host and alter host immune responses. This review highlights efforts made in the past year to elucidate the role of viral infection in rheumatic disease.

Absence of parvovirus B19 infection in chronic fatigue syndrome

OBJECTIVE

To evaluate the presence of infection with parvovirus B19 in patients with chronic fatigue syndrome (CFS) who also had rheumatologic symptoms and mild hematologic abnormalities.

METHODS

Seven patients meeting the Centers for Disease Control and Prevention working case definition for CFS who also had mild leukopenia, thrombocytopenia, or anemia were studied. Bone marrow was aspirated from each patient, and examined for morphologic abnormalities, including features seen in marrow infections with parvovirus B19, as well as for parvoviral DNA, using polymerase chain reaction (PCR) amplification. Serum obtained at the time of marrow aspiration was also evaluated for parvoviral DNA, using the PCR method, and was examined for the presence of IgM and IgG antibodies to the virus.

RESULTS

No evidence of marrow involvement with parvovirus B19 was found in any patient. One patient had antibody evidence of a transient parvoviral infection, during which time an underlying thrombocytopenia worsened.

CONCLUSION

Despite examining a selected group of patients thought most likely to have parvoviral infection, based on clinical and hematologic measures, no evidence of clinically important parvoviral infection was noted. Thus, it seems unlikely that parvovirus B19 plays a role in CFS, even though it has been associated with fibromyalgia, a clinically similar syndrome.

Infection due to parvovirus B19 in patients infected with human immunodeficiency virus

Parvovirus B19 has been described as a cause of chronic anemia in immunosuppressed patients, including those infected with human immunodeficiency virus (HIV). In this study serological assays and the polymerase chain reaction (PCR) were used to establish the prevalence of both prior and active infection due to parvovirus B19 among a general population of 105 HIV-infected individuals (cohort I) and among 22 HIV-infected patients with anemia (cohort II). Eight individuals in cohort I (7.6%) had IgG antibodies to parvovirus B19, while none had B19-specific IgM antibodies. In cohort II, four patients (18.2%) had B19-specific IgG antibodies and none had IgM antibodies. Only one person in cohort I (0.95%) and one person in cohort II (4.5%) had evidence on PCR of persistent infection with parvovirus B19; both of these patients lacked IgG and IgM antibodies to parvovirus. Both individuals with B19 viremia were anemic and had CD4 lymphocyte counts suggesting advanced immunosuppression (< 50/mm3). The observed low prevalences of B19 seropositivity and active B19 infection differ from the rates documented in previous studies and indicate that infection with parvovirus B19 is uncommon in some groups of HIV-infected patients.

Viral infection including HIV and AIDS

Viruses have long been considered candidates for infectious etiologic agents or cofactors in the development of rheumatic diseases. The current epidemic of HIV infection and the recognition of "emerging viruses" has focused interest on the possible role of viruses in pathogenesis of diseases without defined etiology. Over the past year, the role of parvovirus B19 in chronic arthropathy was further defined. Additional data added to our understanding of the mechanisms by which rubella virus may cause chronic arthritis. We were reminded of the potential the togaviruses have to cause epidemics of febrile arthritis. The developing story of hepatitis C virus in essential mixed cryoglobulinemia encourages us to explore strategies for specific antiviral therapies. The members of the herpesvirus family came under scrutiny for their role in Sjögren's syndrome. The retroviruses continue to attract attention because of rheumatic disease syndromes in AIDS patients and the suggestion that still undefined retroviruses may play an etiologic role in rheumatoid arthritis. This review highlights efforts made in the past year to elucidate the role of viral infection in rheumatologic disease.

Established fibromyalgia syndrome and parvovirus B19 infection

OBJECTIVE

To determine the seroprevalence of prior and persistent parvovirus B19 (B19) infection in a group of patients with fibromyalgia (FS) compared with controls.

METHODS

Fifteen female patients with FS who recalled a viral prodrome (+VP) preceding the onset of FS symptoms and eleven patients with FS who did not recall any such illness (-VP) were selected from a referral practice. We excluded patients with FS who described a history of trauma prior to the onset of FS symptoms. Twenty-six female medical workers served as controls. Serum IgM and IgG anti-B19 antibodies were measured by ELISA: Polymerase chain reaction (PCR) products from serum were analyzed by dot blot hybridization for B19 DNA. Fisher's 2-tailed exact test was used to compare the proportion of positive serologies in each group.

RESULTS

No patient or control had positive IgM levels. For all patients with FS, the prevalence of prior B19 infection was comparable to that of healthy controls (11/26 vs 12/26, p = 1.00) and that of the general population. No significant difference was found in the prevalence of prior B19 infection in FS + VP and FS-VP patients (8/15 vs 3/11, p = 0.25). None of the patients or controls showed evidence for persistent B19 viremia, as determined by PCR analysis.

CONCLUSION

Our data do not suggest that B19 plays a pathogenic role in this population of patients with FS. Testing for IgM against B19 within 2-3 months of symptom onset may prove more helpful in further defining the role of B19 in FS.

Parvovirus B19 infection in human immunodeficiency virus type 1-infected persons failing or intolerant to zidovudine therapy

To determine the incidence of B19 infection in patients with AIDS who were being treated with dideoxyinosine, serial sera (n = 28) taken over a 2-year period from 14 individuals were analyzed with respect to anti-B19 serology and the presence of B19 DNA. All 14 individuals were anti-B19 IgM negative. Nine of 14 had B19 viremia by Southern analysis of polymerase chain reaction product. Five of 9 with B19 viremia had > or = 1 anti-B19 IgG-positive sample; none of 5 without viremia had anti-B19 IgG. Four of 9 viremic individuals had serially positive samples. All 4 had severe anemia (hemoglobin < 8.5 g/dL) while taking zidovudine. A fifth individual whose severe anemia resolved after zidovudine was discontinued did not have B19 viremia. Therefore, a significant proportion of this group of patients with AIDS who developed severe anemia while receiving zidovudine had persistent B19 infection. These results suggest that B19 infection should be considered in anemic patients with AIDS.

Viral infection including HIV and AIDS

Viruses have long been considered candidates for infectious etiologic agents or cofactors in the development of rheumatic diseases. The current epidemic of HIV infection has focused both scientific and lay interest on identifying such agents and understanding their role in precipitating and perpetuating disease. During 1992, the role of hepatitis C virus infection in cryoglobulinemia was further defined. Interest in members of the Herpesviridae family was raised. The potential for postvaccination rubella arthritis was popularized. Additional clinical presentations of parvovirus B19 infection were described. Studies in patients and in vitro continued to provide tantalizing clues to the possible role of retroviruses, both exogenous and endogenous, in rheumatic disease. This review highlights efforts made during the past year to elucidate the role of viral infection in rheumatologic disease.