Comprehensive evaluation of cytomorphologic, histologic, and molecular features of DICER1-altered thyroid lesions on FNA: A multipractice experience

BACKGROUND

DICER1 mutations, though infrequent, are encountered on preoperative molecular testing of indeterminate adult and pediatric thyroid fine-needle aspiration (FNA) specimens. Yet, published cytomorphologic features of DICER1-altered thyroid lesions are limited. Cytomorphological features of DICER1-altered thyroid lesions were examined in a multipractice FNA cohort with clinical, radiological, and histologic data.

METHODS

The cohort comprised 18 DICER1-altered thyroid FNAs, with 14 having slides available and eight having corresponding surgical resections. Smears, ThinPrep, and formalin-fixed cell block slides were reviewed and correlated with histology, when available. Clinical and radiologic data were obtained from the medical record.

RESULTS

Most DICER1-altered FNAs were classified as atypia of undetermined significance (94.4%). DICER1 mutations occurred in codons 1709 (50%), 1810 (27.8%), and 1813 (22.2%). One patient had an additional DICER1 p.D1822N variant in both of their FNAs. Lesions were often hypoechoic (35.3%) and solid (47.1%) on ultrasound. Notable cytomorphologic features include mixed but prominent microfollicular or crowded component, variable colloid, and insignificant nuclear atypia. On resection (n = 10), histologic diagnoses ranged from benign follicular adenoma and low-risk follicular thyroid carcinoma to high-grade follicular-derived nonanaplastic thyroid carcinoma. Subcapsular infarct-type change was the most common histologic change. There was no evidence of recurrence or metastasis in eight patients on limited follow-up.

CONCLUSION

DICER1-altered thyroid lesions occurred frequently in young females and FNAs show RAS-like cytomorphology including crowded, mixed macro-/microfollicular pattern, and bland nuclear features. On resection, DICER1-altered thyroid lesions include benign (50%), low-risk lesions (30%), or high-risk malignancies (20%).

Preliminary Investigation into the Prevalence of G6PD Deficiency in a Pediatric African American Population Using a Near-Patient Diagnostic Platform

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is prevalent in the African American population. We identified eighteen G6PD-deficient samples (9%) in a study of residual, de-identified whole blood specimens from 200 African American pediatric patients using a point-of-care instrument. This highlights the possibility of a rapid time to result for G6PD testing, which can be valuable in some clinical scenarios.

Comparison of Mid-turbinate Nasal Swabs, Saliva and Nasopharyngeal Swabs for SARSCoV-2 Reverse Transcription Polymerase Chain Reaction Testing in Pediatric Outpatients

CONTEXT.–

Diagnostic testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in symptomatic and asymptomatic children remains integral to care, particularly for supporting return to and attendance in schools. The concordance of SARS-CoV-2 detection in children using various specimen types has not been widely studied.

OBJECTIVE.–

To compare three sample types for SARS-CoV-2 PCR testing in children collected and tested at a single facility.

DESIGN.–

We prospectively recruited 142 symptomatic and asymptomatic children into a sample comparison study performed in a single healthcare system. Each child provided self-collected saliva, and a trained healthcare provider collected a mid-turbinate nasal swab and nasopharyngeal (NP) swab. Specimens were assayed within 24 hours of collection using reverse transcriptase-polymerase chain reaction (RT-PCR) to detect SARS-CoV-2 on a single testing platform.

RESULTS.–

Concurrently collected saliva and mid-turbinate swabs had >95% positive agreement with NP swabs when obtained within 10 days of symptom onset. Positive agreement of saliva and mid-turbinate samples collected from children with symptom onset >10 days prior, or without symptoms, was 82% compared to NP swab samples. Cycle threshold (Ct) values for mid-turbinate nasal samples more closely correlated with Ct values from NP samples than saliva sample Ct values.

CONCLUSIONS.–

These findings suggest that all three sample types from children are useful for SARS-CoV-2 diagnostic testing by RT-PCR, and that concordance is greatest when the child has symptoms of coronavirus disease 2019 (COVID-19) within the past 10 days. This study provides scientific justification for utilizing sample types other than the NP swab for SARS-CoV-2 testing in pediatric populations.

Extensive Perivillous Fibrin and Intervillous Histiocytosis in a SARS-CoV-2 Infected Placenta From an Uninfected Newborn: A Case Report Including Immunohistochemical Profiling

Placental infection by SARS-CoV-2 with various pathologic alterations reported. Inflammatory findings, such as extensive perivillous fibrin deposition and intervillous histiocytosis, have been postulated as risk factors for fetal infection by SARS-CoV-2. We describe the placental findings in a case of a 31-year-old mother with SARS-CoV-2 infection who delivered a preterm female neonate who tested negative for SAR-CoV2 infection. Placental examination demonstrated a small for gestational age placenta with extensive intervillous histiocytosis, syncytiotrophoblast karyorrhexis, and diffuse intervillous fibrin deposition. Immunohistochemical staining demonstrated infection of the syncytiotrophoblasts by SARS-CoV-2 inversely related to the presence of intervillous histiocytes and fibrin deposition. Our case demonstrates that despite extensive placental pathology, no fetal transmission of SARS-CoV-2 occurred, as well as postulates a relationship between placental infection, inflammation, and fibrin deposition.

Autopsy Study of Calretinin Immunohistochemistry in the Anorectal Canal in Young Infants and Potential Implications for Rectal Biopsy Approach in the Neonatal Period

BACKGROUND

Absent submucosal ganglion cells in biopsies 1-3 cm above the pectinate line establishes the pathologic diagnosis of Hirschsprung Disease (HD). Calretinin stains both ganglion cells and their mucosal neurites and has gained importance in HD diagnosis. Absent calretinin positive mucosal neurites in biopsies at the appropriate level above the pectinate line is highly specific for HD. Whether this applies to lower biopsies is uncertain. To address this, we studied anorectal canal autopsy specimens from infants.

METHODS

We performed an autopsy study of infant anorectal canal specimens to describe calretinin staining in this region. Calretinin staining was correlated with histologic and gross landmarks.

RESULTS

In all 15 non-HD specimens, calretinin positive mucosal neurites were present in glandular mucosa up to the anorectal line where neurites rapidly diminished. Age range was preterm 26 weeks to 3 months.

CONCLUSIONS

Calretinin positive mucosal neurites are present in glandular mucosa up to the anorectal line in young infants. This is potentially important regarding neonatal HD biopsy level and diagnosis. Positive calretinin staining at the anorectal line favors normal innervation making HD unlikely. Absent calretinin positive neurites in glandular mucosa is worrisome for HD in young infants, regardless of location.

Correlation of SARS-CoV-2 Subgenomic RNA with Antigen Detection in Nasal Midturbinate Swab Specimens

Among symptomatic outpatients, subgenomic RNA of severe acute respiratory syndrome coronavirus 2 in nasal midturbinate swab specimens was concordant with antigen detection but remained detectable in 13 (82.1%) of 16 nasopharyngeal swab specimens from antigen-negative persons. Subgenomic RNA in midturbinate swab specimens might be useful for routine diagnostics to identify active virus replication.

Multidisciplinary assessment of the Abbott BinaxNOW SARS-CoV-2 point-of-care antigen test in the context of emerging viral variants and self-administration

While there has been significant progress in the development of rapid COVID-19 diagnostics, as the pandemic unfolds, new challenges have emerged, including whether these technologies can reliably detect the more infectious variants of concern and be viably deployed in non-clinical settings as "self-tests". Multidisciplinary evaluation of the Abbott BinaxNOW COVID-19 Ag Card (BinaxNOW, a widely used rapid antigen test, included limit of detection, variant detection, test performance across different age-groups, and usability with self/caregiver-administration. While BinaxNOW detected the highly infectious variants, B.1.1.7 (Alpha) first identified in the UK, B.1.351 (Beta) first identified in South Africa, P.1 (Gamma) first identified in Brazil, B.1.617.2 (Delta) first identified in India and B.1.2, a non-VOC, test sensitivity decreased with decreasing viral loads. Moreover, BinaxNOW sensitivity trended lower when devices were performed by patients/caregivers themselves compared to trained clinical staff, despite universally high usability assessments following self/caregiver-administration among different age groups. Overall, these data indicate that while BinaxNOW accurately detects the new viral variants, as rapid COVID-19 tests enter the home, their already lower sensitivities compared to RT-PCR may decrease even more due to user error.

OncoKids: A Comprehensive Next-Generation Sequencing Panel for Pediatric Malignancies

The OncoKids panel is an amplification-based next-generation sequencing assay designed to detect diagnostic, prognostic, and therapeutic markers across the spectrum of pediatric malignancies, including leukemias, sarcomas, brain tumors, and embryonal tumors. This panel uses low input amounts of DNA (20 ng) and RNA (20 ng) and is compatible with formalin-fixed, paraffin-embedded and frozen tissue, bone marrow, and peripheral blood. The DNA content of this panel covers the full coding regions of 44 cancer predisposition loci, tumor suppressor genes, and oncogenes; hotspots for mutations in 82 genes; and amplification events in 24 genes. The RNA content includes 1421 targeted gene fusions. We describe the validation of this panel by using a large cohort of 192 unique clinical samples that included a wide range of tumor types and alterations. Robust performance was observed for analytical sensitivity, reproducibility, and limit of detection studies. The results from this study support the use of OncoKids for routine clinical testing of a wide variety of pediatric malignancies.

Comparison of Alere i Strep A Rapid Molecular Assay With Rapid Antigen Testing and Culture in a Pediatric Outpatient Setting

OBJECTIVES

Group A Streptococcus (GAS) is the most common bacterial cause of pediatric acute pharyngitis, and its quick identification is important for subsequent treatment. We sought to determine whether molecular GAS-based testing can successfully replace GAS antigen testing and subsequent culture in a pediatric urgent care center.

METHODS

We tested 160 patient oropharyngeal samples by a rapid antigen GAS test, the Alere i Strep A test, and throat culture in a pediatric urgent care setting and calculated basic statistical metrics.

RESULTS

The sensitivity and specificity of the molecular test were 98% and 100%, respectively, compared with culture. There was a 9% false-positive rate with the rapid antigen-based testing.

CONCLUSIONS

The Alere test is sufficiently sensitive and specific for definitive GAS testing in a pediatric urgent care setting. This implementation has enabled us to provide definitive patient results at the time of each patient encounter.

Validation of an Enclosed Blood Collection System in a Pediatric Laboratory

Background

Preanalytical, analytical, and postanalytical issues are often magnified in pediatric laboratories, and traditional vacuum-based blood tubes can contribute to some of these issues. Because of this, we investigated adopting an enclosed blood collection system that can perform vacuum or gentle aspiration blood collection, eliminating syringes, transfer device, and transfer steps, as well as potentially minimizing preanalytical error in the pediatric laboratory. We embarked on a validation of this tube system, in comparison with our current collection tubes, across most in-house tests at a large pediatric hospital.

Methods

Twenty adult volunteers were recruited. Blood was drawn into lithium heparin, serum, EDTA, and citrate tubes of each commercial tube type for comparison. For some tests, remnant blood from pediatric syringe draws was used when available. Samples were then processed and analyzed across all general areas of the clinical laboratory, and correlations of the results from the 2 tube systems were performed.

Results

Across 95 tests in the core laboratory and blood bank, almost all demonstrated clinically acceptable comparisons, with most R values >0.90. Only 3 of 95 tests demonstrated clinically significant differences between the tube systems.

Conclusions

Our validation of the enclosed blood collection system demonstrated acceptable results when compared with our current collection tubes. Additionally, with some minor modifications, our automated instruments could utilize ultralow-volume tubes from the enclosed blood collection system for direct tube sampling, which is impossible using our current small-volume tubes with our main chemistry analyzer.

The Impact of Disruption of the Care Delivery System by Commercial Laboratory Testing in a Children's Health Care System

CONTEXT.—

Disruption of outpatient laboratory services by routing the samples to commercial reference laboratories may seem like a cost-saving measure by the payers, but results in hidden costs in quality and resources to support this paradigm.

OBJECTIVE.—

To identify differences when outpatient tests are performed at the Children's Healthcare of Atlanta (Children's) Hospital lab compared to a commercial reference lab, and the financial costs to support the reference laboratory testing.

DESIGN.—

Outpatient testing was sent to 3 different laboratories specified by the payer. Orders were placed in the Children's electronic health record, blood samples were drawn by the Children's phlebotomists, samples were sent to the testing laboratory, and results appeared in the electronic health record. Data comparing the time to result, cancelled samples, and cost to sustain the system of ordering and reporting were drawn from multiple sources, both electronic and manual.

RESULTS.—

The median time from phlebotomy to result was 0.7 hours for testing at the Children's lab and 20.72 hours for the commercial lab. The median time from result posting to caregiver acknowledgment was 5.4 hours for the Children's lab and 18 hours for the commercial lab. The commercial lab cancelled 2.7% of the tests; the Children's lab cancelled 0.8%. The financial cost to support online ordering and reporting for testing performed at commercial labs was approximately $640,000 per year.

CONCLUSIONS.—

Tangible monetary costs, plus intangible costs related to delayed results, occur when the laboratory testing system is disrupted.

Testing implications of varying targets for Bordetella pertussis: comparison of the FilmArray Respiratory Panel and the Focus B. pertussis PCR assay

BACKGROUND

The FilmArray Respiratory Panel (RP) detects multiple pathogens, including Bordetella pertussis. The multiplex PCR system is appropriate for a core laboratory or point of care due to ease of use. The purpose of this study is to compare the analytical sensitivity of the FilmArray RP, which targets the promoter region of the B. pertussis toxin gene, with the Focus real-time PCR assay, which targets the insertion sequence IS481.

METHODS

Seventy-one specimens from patients aged 1 month to 18 years, which had tested positive for B. pertussis using the Focus assay, were analysed using the FilmArray RP.

RESULTS

Forty-six specimens were positive for B. pertussis by both the Focus and the FilmArray RP assays. Twenty-five specimens were negative for B. pertussis using the FilmArray RP assay, but positive using the Focus assay.

CONCLUSIONS

The FilmArray RP assays will detect approximately 1/3 less cases of B. pertussis than the Focus assay.

Impact of a rapid respiratory panel test on patient outcomes

CONTEXT

Evolution of polymerase chain reaction testing for infectious pathogens has occurred concurrent with a focus on value-based medicine.

OBJECTIVE

To determine if implementation of the FilmArray rapid respiratory panel (BioFire Diagnostics, Salt Lake City, Utah) (hereafter RRP), with a shorter time to the test result and expanded panel, results in different outcomes for children admitted to the hospital with an acute respiratory tract illness.

DESIGN

Patient outcomes were compared before implementation of the RRP (November 1, 2011, to January 31, 2012) versus after implementation of the RRP (November 1, 2012, to January 31, 2013). The study included inpatients 3 months or older with an acute respiratory tract illness, most admitted through the emergency department. Testing before RRP implementation used batched polymerase chain reaction analysis for respiratory syncytial virus and influenza A and B, with additional testing for parainfluenza 1 through 3 in approximately 11% of patients and for human metapneumovirus in less than 1% of patients. The RRP tested for respiratory syncytial virus, influenza A and B, parainfluenza 1 through 4, human metapneumovirus, adenovirus, rhinovirus/enterovirus, and coronavirus NL62.

RESULTS

The pre-RRP group had 365 patients, and the post-RRP group had 771 patients. After RRP implementation, the mean time to the test result was shorter (383 minutes versus 1119 minutes, P < .001), and the percentage of patients with a result in the emergency department was greater (51.6% versus 13.4%, P < .001). There was no difference in whether antibiotics were prescribed, but the duration of antibiotic use was shorter after RRP implementation (P = .003) and was dependent on receiving test results within 4 hours. If the test result was positive, the inpatient length of stay (P = .03) and the time in isolation (P = .03) were decreased after RRP implementation compared with before RRP implementation.

CONCLUSIONS

The RRP decreases the duration of antibiotic use, the length of inpatient stay, and the time in isolation.

Monocytopenia as a diagnostic clue to pediatric B-lymphoblastic leukemia with rare circulating blasts

B-lymphoblastic leukemia/lymphoma (B-LL) is the most common childhood cancer. Circulating blasts in the peripheral blood may be rare (≤1%) and missed, even when flow cytometric immunophenotyping is performed, leading to a false-negative report. The records from all patients with a new diagnosis of B-LL between January 2009 and December 2011 at our institution were reviewed. Of 130 cases with peripheral blood flow cytometry, 15 had a blast count of ≤1%, with 14 having electronic files for gating monocytes. The percentage of monocytes by flow cytometry and absolute monocyte counts (AMCs) were compared with peripheral blood samples that were negative by flow cytometry, sent due to cytopenia of at least 1 lineage (n  =  39). The monocytes from the patients with leukemia averaged 0.8% and were statistically fewer than the negative controls, which averaged 7.1% (P < 0.001). Eleven of the 14 (79%) patients with leukemia had monocytes <1%, compared to only 3 (8%) of the negative controls. The AMCs were also significantly lower (P < 0.001), with 93% of the leukemia group having an AMC <100 cells/µL, compared to only 28% of the negative controls. In patients with cytopenias, percentage of monocytes may be an important diagnostic clue in determining the presence of occult leukemia. If flow cytometry is performed, acquisition of more than the standard 10,000 events is necessary to adequately assess for leukemia. If monocytes are <1% by flow cytometry in the setting of cytopenias, bone marrow examination is recommended, even with negative peripheral blood flow cytometry.

Placental pathology suggesting that preeclampsia is more than one disease

OBJECTIVE

Our purpose was to evaluate the placental pathology in women with preeclampsia occurring at varying gestational ages.

STUDY DESIGN

This was a secondary analysis of a prospective observational study of placentas from prespecified complicated pregnancies routinely submitted for standardized examination. For this study, a database of placental diagnoses from liveborn singleton gestations without major malformations was linked to a computerized obstetric database. The rates of standardized placental findings including vascular (atherosis, infarction) and nonvascular (hyperplasia) changes were evaluated according to gestational age at diagnosis of preeclampsia.

RESULTS

Between Jan. 1, 2001, and Sept. 30, 2007, a total of 7122 women with pregnancies complicated by preeclampsia were delivered at our hospital. Of these, 1210 (17%) had placental examinations. Within this cohort, 209, 355, and 646 women were diagnosed with preeclampsia at gestations of 24(0/67) to 33(6/7), 34(0/7) to 36(6/7), and 37(0/7) weeks or longer, respectively. Placental findings revealed hypoplasia was significantly associated with preeclampsia early in the third trimester, and histological evidence of placental vascular lesions was significantly increased at gestations of 24(0/67) to 33(6/7) weeks (53%) compared with 34% and 26% at 34(0/7) to 36(6/7) and 37 weeks or longer, respectively (P < .001).

CONCLUSION

The placentas of women with preeclampsia onset before 34 weeks' gestation were significantly different from those with preeclampsia at term. The former group demonstrated placental findings predominantly consistent with insufficiency because of vascular abnormalities. Such differing placental findings support the hypothesis that preeclampsia is a different disease, depending on the gestational age at diagnosis.

An immunologic basis for placental insufficiency in fetal growth restriction

OBJECTIVE

We sought to determine whether chronic villitis, an immunologic disease of the placenta, was related to fetal growth restriction.

METHODS

Beginning in October 1999, a protocol was instituted that required placentas of high-risk births be submitted for standardized histological examination. Chronic villitis was diagnosed when a lymphohistiocytic infiltrate involving placental villi was present and was graded according to the extent and location of the infiltrate. Fetal growth restriction was defined as weight less than 3rd, 5th, and 10th percentiles. Placental hypoplasia was defined as weight less than 10th percentile.

RESULTS

In the 10,204 placental examinations that were performed, low-grade and high-grade chronic villitis was associated with hypoplastic placentas and fetal growth restriction. Infants with placentas with low-grade and high-grade chronic villitis were more likely to require cesarean delivery for nonreassuring fetal heart rate compared with controls (27% and 25% versus 21%; p < 0.05). Fetal acidemia (umbilical artery pH < 7.0) was associated with high-grade chronic villitis compared with controls (4% versus 2%; p < 0.05).

CONCLUSION

Chronic villitis was associated with anatomic and functional placental insufficiency manifested as placental hypoplasia, growth restriction, increased risk of cesarean for nonreassuring fetal heart rate, and fetal acidemia. These findings support an immunologic basis for fetal growth restriction.

A lean laboratory: operational simplicity and cost effectiveness of the Luminex xTAG™ respiratory viral panel

During certain months of the year, viral respiratory infections lead to a dramatic increase in pediatric emergency room visits and hospital admissions. Rapid identification of the infectious organism results in timely treatment and reductions in hospital cost and length of stay. Before the introduction of molecular testing to the virology laboratory, diagnosis relied on the standard methods of immunofluorescence and culture. These tests can be labor-intensive and costly. Recent studies have demonstrated the higher sensitivity, faster turnaround, and broader diagnostic spectrum provided by multiplexed RT-PCR assays. Data comparing the laboratory cost and labor efficiency of the tests are lacking. To address this issue, we chose to implement the principles of operational workflow analysis using lean methodology to critically evaluate the potential advantages of a multiplexed RT-PCR assay both in terms of workflow and cost effectiveness. Our results indicated that the implementation of the Luminex xTAG Respiratory Viral Panel (RVP) resulted in a standardized workflow with decreased requirements in laboratory cost as well as improvement in efficiency. In summary, we demonstrate that, in our laboratory, the Luminex xTAG RVP is more operationally streamlined and cost-effective than standard viral direct fluorescent antibody and culture. Further studies are needed to highlight additional benefits of the test, including shortened hospital stay and improved patient outcome.

Teaching Pediatric Laboratory Medicine to Pathology Residents

Context.—Laboratory data are essential to the medical care of fetuses, infants, children, and adolescents. However, the performance and interpretation of laboratory tests on specimens from these patients, which may constitute a significant component of the workload in general hospitals and integrated health care systems as well as specialized perinatal or pediatric centers, present unique challenges to the clinical pathologist and the laboratory. Therefore, pathology residents should receive training in pediatric laboratory medicine.

Objective.—Children's Health Improvement through Laboratory Diagnostics, a group of pathologists and laboratory scientists with interest and expertise in pediatric laboratory medicine, convened a task force to develop a list of curriculum topics, key resources, and training experiences in pediatric laboratory medicine for trainees in anatomic and clinical pathology or straight clinical pathology residency programs and in pediatric pathology fellowship programs.

Data Sources.—Based on the experiences of 11 training programs, we have compiled a comprehensive list of pediatric topics in the areas of clinical chemistry, endocrinology, hematology, urinalysis, coagulation medicine, transfusion medicine, immunology, microbiology and virology, biochemical genetics, cytogenetics and molecular diagnostics, point of care testing, and laboratory management. This report also includes recommendations for training experiences and a list of key texts and other resources in pediatric laboratory medicine.

Conclusions.—Clinical pathologists should be trained to meet the laboratory medicine needs of pediatric patients and to assist the clinicians caring for these patients with the selection and interpretation of laboratory studies. This review helps program directors tailor their curricula to more effectively provide this training.

Unusual immunophenotype of CD8+ T cells in familial hemophagocytic lymphohistiocytosis

Familial hemophagocytic lymphohistiocytosis (FHL) is an inherited, fatal disorder of infancy. We report here a 17-day-old female infant who presented with high fever, hepatosplenomegaly, hypertriglyceridemia, hypofibrinogenemia, thrombocytopenia, and liver failure. Leukocytosis was detected with circulating “atypical” lymphoid cells. Flow cytometric studies revealed expanded subpopulations of CD8+ T cells with unusual immunophenotypic features, including a subset that lacked CD5 expression. A liver biopsy showed hemophagocytic lymphohistiocytosis with exuberant infiltrates of CD8+ T cells that lacked perforin. Mutational studies revealed a 666C→A (H222Q) missense mutation in the perforin gene. T-cell receptor studies on flow-sorted T-cell subpopulations revealed no evidence of monoclonality. Analysis of T-cell receptor excision circle levels indicated long proliferative history in the aberrant CD8+ T-cell subsets. This case provides an instructive example of uncontrolled reactive proliferation of CD8+ T cells in FHL, resulting in atypical morphology and unusual immunophenotypic features that might suggest malignancy in other clinical settings.

Dysmorphic villi mimicking partial mole in a case with del(18)(q21)

In this article, we report the histopathologic findings in a placenta from an early second trimester abortion. The placental villi showed prominent scalloping with many intravillous trophoblastic pseudoinclusions and mild trophoblastic hyperplasia, mimicking the morphology of partial hydatidiform mole. The placental karyotype was 46,XY,del(18)(q21). These histopathologic changes have been previously described in numerical chromosomal aberrations like triploidy, tetraploidy, and trisomies, but not in structural chromosomal abnormalities.

Alpha-synuclein expression in the developing human brain

Alpha (alpha)-synuclein is a presynaptic protein, abnormal expression of which has been associated with neurodegenerative and neoplastic diseases. It is abundant in the developing vertebrate central nervous system (CNS), but less is known about its developmental expression in the human CNS. Immunohistochemical expression of alpha-synuclein was studied in 39 fetal, perinatal, pediatric, and adolescent brains. Perikaryal expression of alpha-synuclein is observed as early as 11-wk gestation in the cortical plate. Several discrete neuronal groups in the hippocampus, basal ganglia, and brain stem express perikaryal alpha-synuclein by 20-wk gestation, persisting through the first few years of life. In the cerebellum, alpha-synuclein is present by 21-wk gestation and persists into adult life as a coarse granular neuropil reaction product in the internal granular layer, and as a diffuse neuropil "blush" in the molecular layer. The germinal matrix, glia, endothelial cells, external granular layer, Pukinje cells, and dentate neurons are consistently negative for alpha-synuclein. We conclude that alpha-synuclein is expressed very early in human gestation, and that its distribution and temporal sequence of expression varies in discrete neuronal groups. Perikaryal alpha-synuclein starts disappearing from the neuronal cytosol in early childhood, and only the neuropil retains immunoreactivity into adulthood. The reappearance of alpha-synuclein in the adult neuronal cytosol in certain disease processes may represent reemergence of cues from an earlier developmental stage as part of a stress response.

Respiratory syncytial virus induces pneumonia, cytokine response, airway obstruction, and chronic inflammatory infiltrates associated with long-term airway hyperresponsiveness in mice

BACKGROUND

Respiratory syncytial virus (RSV) infection is associated with acute morbidity (e.g., pneumonia and airway obstruction [AO]) and long-term complications (e.g., airway hyperresponsiveness [AHR]). We present a comprehensive evaluation of the acute and chronic phases of RSV respiratory tract infection, using a mouse model.

METHODS

BALB/c mice were inoculated with RSV and monitored for 154 days. RSV loads and cytokines were measured in bronchoalveolar lavage (BAL) samples. Pneumonia severity was assessed using a standard histopathologic score, and pulmonary function was determined by plethysmography.

RESULTS

RSV-infected mice exhibited viral replication that peaked on day 4-5 and became undetectable by day 7. These mice developed acute pneumonia (peak days, 4-5) and chronic pulmonary inflammatory infiltrates that lasted up to 154 days after inoculation. BAL concentrations of tumor necrosis factor- alpha, interleukin (IL)-6, interferon- gamma, IL-4, IL-10, KC (an IL-8 homologue), MIG (CXCL9), RANTES, macrophage inflammatory protein-1 alpha, and eotaxin were significantly higher in RSV-infected mice than in control mice. RSV-infected mice developed acute AO during the first week of infection that persisted for 42 days. RSV-infected mice also showed significant AHR in response to methacholine up to 154 days.

CONCLUSION

This model provides a means to investigate the immunopathogenesis of RSV infection and its association with reactive airway disease.

Antimicrobial and immunologic activities of clarithromycin in a murine model of Mycoplasma pneumoniae-induced pneumonia

Because macrolide antibiotics are hypothesized to possess immunomodulatory activity independent of their antimicrobial activity, we evaluated the immunomodulatory effect of clarithromycin in a murine model of lung inflammation induced by either live or UV-killed Mycoplasma pneumoniae. BALB/c mice were intranasally inoculated once with live or UV-killed M. pneumoniae. Clarithromycin (25 mg/kg of body weight) or placebo was subcutaneously administered once daily in both groups of mice. In mice infected with live M. pneumoniae, clarithromycin treatment significantly reduced quantitative M. pneumoniae bronchoalveolar lavage (BAL) culture, pulmonary histopathologic scores (HPS), and airway resistance-obstruction (as measured by plethysmography) compared with placebo. Concentrations of tumor necrosis factor alpha, gamma interferon, interleukin-6 (IL-6), mouse KC (functional IL-8), JE/MCP-1, and MIP-1alpha in BAL fluid were also significantly decreased in mice infected with live M. pneumoniae given clarithromycin. In contrast, mice inoculated with UV-killed M. pneumoniae had no significant reduction in HPS, airway resistance-obstruction, or BAL cytokine or chemokine concentrations in response to clarithromycin administration. Clarithromycin therapy demonstrated beneficial effects (microbiologic, histologic, respiratory, and immunologic) on pneumonia in the mice infected with live M. pneumoniae; this was not observed in the mice inoculated with UV-killed M. pneumoniae.

Biochemical abnormality associated with Smith-Lemli-Opitz syndrome in an infant with features of Rutledge multiple congenital anomaly syndrome confirms that the latter is a variant of the former

We describe a female infant with morphologic features of Rutledge multiple-congenital-anomaly syndrome (RMCAS) and biochemical features of Smith-Lemli-Opitz syndrome (SLOS). She had microcephaly with hypoplastic cerebral frontal lobes and cerebellum, agenesis of the splenium of corpus callosum, abnormal facies including hypertelorism with bilateral inner epicanthal folds, a broad nasal bridge with slightly anteverted nares and patent choanae, low set ears and complex conchal formation, high-arched palate and thick maxillary alveolar ridges, and micrognathia. Her chest was broad, genitalia were ambiguous, and uterus was bicornuate. Skeletal abnormalities included a hypoplastic appendicular skeleton, post-axial hexadactyly of the right hand and the left foot, syndactyly of bilateral 2nd-3rd toes and left 5th-6th toes, right talipes varus and left talipes valgus, and fused L5-S1 vertebrae. Congenital heart disease consisted of hypoplastic left heart, coronary sinus agenesis, ostium secundum and ostium primum defects, and a thickened septum primum. The lungs were hypolobated and the kidneys manifested oligopapillary hypoplasia. Total colonic Hirschsprung disease was noted microscopically. Analysis of liver tissue taken at postmortem examination revealed the ratio of 7-dehydrocholesterol and cholesterol to be 143 (expected, 0.28 +/- 0.28). Although initially described as a distinct syndrome, RMCAS was merged with the severe form of SLOS, because of significantly overlapping features [Online Mendelian Inheritance in Man (OMIM) #268670]. The biochemical data showing an excess of 7-dehydrocholesterol and low cholesterol in the liver tissue of our case supports this viewpoint.

Giant cell tumor of the skin: a morphologic and immunohistochemical study of five cases

Giant cell tumor (GCT) of the skin is a rare entity that possesses similar gross and histologic features to GCT of bone. When located predominantly in the dermis GCT has been mistaken for benign fibrous histiocytoma and atypical fibroxanthoma. We report the clinical, morphologic, and immunohistochemical features of five cases of GCT of the skin. With one exception, all tumors are confined to the dermis. Patients' ages range from 6 to 78 years (median, 73 years) with a male to female ratio of 3:2. Gross and histologic features of the lesions are similar to those of GCT of bone (eg, brown fleshy tumor and a biphasic population of mononuclear cells admixed with osteoclast-like giant cells, respectively). The nuclei of the giant cells are similar to those of the mononuclear cells. A fascicular pattern with focal storiform arrangement of spindle neoplastic cells is noted in two cases. The osteoclast-like giant cells and some of the mononuclear cells are strongly positive for CD68, alpha-1-antitrypsin, and alpha-1-antichymotrypsin. Only the mononuclear cells express smooth muscle actin focally in one case. Both the osteoclast-like giant cells and the mononuclear cells are negative for cytokeratins (AE1/AE3 and CAM5.2) and S-100 protein in all cases. One patient developed lung metastases at presentation and local recurrence 4 months status post surgery. All patients are without evidence of disease 1 month to 12 years status post surgery. Cutaneous GCTs are low-grade sarcomas that can recur locally and infrequently metastasize. These tumors should be distinguished from a variety of cutaneous neoplasms that contain multinucleated giant cells.

Long-chain L-3-hydroxyacyl-coenzyme a dehydrogenase deficiency: a molecular and biochemical review

Since the first report of long-chain L-3-hydroxyacyl-coenzyme A dehydrogenase deficiency a little more than a decade ago, its phenotypic and genotypic heterogeneity in individuals homozygous for the enzyme defect has become more and more evident. Even more interesting is its association with pregnancy-specific disorders, including preeclampsia, HELLP syndrome (hemolysis, elevated liver enzymes, low platelets), hyperemesis gravidarum, acute fatty liver of pregnancy, and maternal floor infarct of the placenta. In this review we discuss the biochemical and molecular basis, clinical features, diagnosis, and management of long-chain L-3-hydroxyacyl-coenzyme A dehydrogenase deficiency.

Evidence for fatty acid oxidation in human placenta, and the relationship of fatty acid oxidation enzyme activities with gestational age

Fetal disorders of mitochondrial fatty acid oxidation have recently been associated with obstetric complications including pre-eclampsia, Hemolysis, Elevated Liver enzymes, Low Platelets (HELLP) syndrome, placental floor infarct, and Acute Fatty Liver of Pregnancy (AFLP). These diseases occur in about a third of the mothers who are heterozygous for a defect in long chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) enzyme and who bear a fetus homozygous for the defect. The mechanism of this association is not clearly understood. In this study, we provide evidence that the placenta may be the site of production of toxic intermediates of fatty acid metabolism, which accumulate to cause liver damage in the mother. We show that two critical enzymes of long chain fatty acid metabolism, long chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and short chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD), are active in the normal human placenta. There is an inverse correlation between the enzyme activity of both the enzymes and maternal gestational age during the second and third trimesters. We believe that the demonstration of fatty acid oxidation enzyme activity by the placenta is the first step towards assessing a possible role for fetal/placental fatty acid oxidation defects in the pathogenesis of a subset of pregnancy complications.

Mycoplasma pneumoniae induces chronic respiratory infection, airway hyperreactivity, and pulmonary inflammation: a murine model of infection-associated chronic reactive airway disease

Because chronic Mycoplasma pneumoniae respiratory infection is hypothesized to play a role in asthma, the potential of M. pneumoniae to establish chronic respiratory infection with associated pulmonary disease was investigated in a murine model. BALB/c mice were intranasally inoculated once with M. pneumoniae and examined at 109, 150, 245, 368, and 530 days postinoculation. M. pneumoniae was detected in bronchoalveolar lavage fluid by culture or PCR in 70 and 22% of mice at 109 and 530 days postinoculation, respectively. Lung histopathology was normal up to 368 days postinoculation. At 530 days, however, 78% of the mice inoculated with M. pneumoniae demonstrated abnormal histopathology characterized by peribronchial and perivascular mononuclear infiltrates. A mean histopathologic score (HPS) at 530 days of 5.1 was significantly greater (P < 0.01) than that for controls (HPS score of 0). Serum anti-M. pneumoniae immunoglobulin G was detectable in all of the mice inoculated with M. pneumoniae and was inversely correlated with HPS (r = -0.95, P = 0.01) at 530 days postinoculation. Unrestrained whole-body plethysmography measurement of enhanced pause revealed significantly elevated airway methacholine reactivity in M. pneumoniae-inoculated mice compared with that in controls at 245 days (P = 0.03) and increased airway obstruction at 530 days (P = 0.01). Murine M. pneumoniae respiratory infection can lead to chronic pulmonary disease characterized by airway hyperreactivity, airway obstruction, and histologic inflammation.

Mucositis in the oncology patient

Mucositis is a common side effect related to the treatment of cancer. Many agents have been tested for the prevention and management of mucositis, but the data regarding a number of the agents are conflicting. This article describes the incidence of mucositis in individuals with cancer and the various agents used in its prevention and management. Nurses play an important role in the management of patients with mucositis and in identifying agents that may decrease the patient's risk for mucositis and aid healing.

Prevalence and cellular reservoir of latent human herpesvirus 6 in tonsillar lymphoid tissue

There are few studies that examine prevalence, quantity, and cellular proclivity of latent human herpesvirus 6 (HHV-6) in healthy populations. We examined 69 tonsils with paired blood specimens from children without evidence of acute infection. By polymerase chain reaction (PCR), HHV-6 was detected at low levels in 100% of tonsils and 39% of blood samples (n = 27), suggesting that prevalence of latent HHV-6 infection is high in children and may be underestimated by PCR analysis of blood. Although HHV-6A and HHV-6B were detected, HHV-6B predominated, being found in 97% of samples (n = 67). Tonsil sections from 7 cases were examined by in situ hybridization using 2 HHV-6 probes and immunohistochemical analysis. Using both in situ hybridization and immunohistochemical analysis, all tissues revealed marked HHV-6-specific staining in the squamous epithelium of the tonsillar crypts and rare positive lymphocytes. We conclude that HHV-6 is present universally in tonsils of children, and tonsillar epithelium may be an important viral reservoir in latent infection.

Elevated cytokine and chemokine levels and prolonged pulmonary airflow resistance in a murine Mycoplasma pneumoniae pneumonia model: a microbiologic, histologic, immunologic, and respiratory plethysmographic profile

Because Mycoplasma pneumoniae is hypothesized to play an important role in reactive airway disease/asthma, a comprehensive murine model of M. pneumoniae lower respiratory infection was established. BALB/c mice were intranasally inoculated once with M. pneumoniae and sacrificed at 0 to 42 days postinoculation. All mice became infected and developed histologic evidence of acute pulmonary inflammation, which cleared by 28 days postinoculation. By contrast, M. pneumoniae persisted in the respiratory tract for the entire 42 days studied. Tumor necrosis factor alpha, gamma interferon, interleukin-6 (IL-6), KC (functional IL-8), MIP-1alpha, and MCP-1/JE concentrations were significantly elevated in bronchoalveolar lavage samples, whereas IL-4 and IL-10 concentrations were not significantly elevated. Pulmonary airflow resistance, as measured by plethysmography, was detected 1 day postinoculation and persisted even after pulmonary inflammation had resolved at day 28. Serum anti-M. pneumoniae immunoglobulin G titers were positive in all mice by 35 days. This mouse model provides a means to investigate the immunopathogenesis of M. pneumoniae infection and its possible role in reactive airway disease/asthma.

Predictive value of quantitative PCR-based viral burden analysis for eight human herpesviruses in pediatric solid organ transplant patients

Human herpesviruses can cause significant morbidity and mortality in pediatric solid organ transplant recipients. It was hypothesized that viral burden quantification by polymerase chain reaction using an internal calibration standard could aid in distinguishing between viral disease and latency. Here we report the results of a 2-year prospective study of 27 pediatric solid organ (liver, kidney, or heart) transplant recipients in which multiple samples were analyzed for levels of all eight human herpesviruses by internal calibration standard-polymerase chain reaction. Herpes simplex viruses 1 and 2, varicella-zoster virus, and Kaposi's sarcoma-associated herpesvirus were not detected in any of these samples. Human herpesvirus types 6 and 7 were detected in half of the patients, but were present at low levels, similar to those found in reference populations. Epstein-Barr virus (EBV) and cytomegalovirus (CMV) were detected in 89% and 56% of the patients, respectively. Viral burden analysis suggested distinct patient populations for CMV, with a natural cutoff of 10,000 viral targets/ml blood strongly associated with disease. In some cases, a dramatic increase in CMV levels preceded clinical evidence of disease by several weeks. EBV viral burden was relatively high in the only patient presenting with an EBV syndrome. However, two other patients without evidence of EBV disease had single samples with high EBV burden. Rapid reduction in both EBV and CMV burden occurred with antiviral treatment. These data suggest that viral burden analysis using internal calibration standard-polymerase chain reaction for CMV, and possibly other herpesviruses, is an effective method for monitoring pediatric transplant patients for significant herpesvirus infection and response to therapy.

Cytomegalovirus and human herpesvirus 6, but not human papillomavirus, are present in neonatal giant cell hepatitis and extrahepatic biliary atresia

The purpose of our study was to confirm reports of an association of human papillomavirus (HPV) with neonatal giant cell hepatitis (GCH) and biliary atresia (BA), and to expand these studies to include cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 6 (HHV6), and parvovirus B19 (PVB19). Frozen hepatic tissue was available for polymerase chain reaction (PCR) analysis in 19 cases of GCH or BA and 8 controls. Nested PCR to detect HPV types 6, 16, 18, and 33 was followed by 32P hybridization with generic probes. PCR followed by hybridization with a digoxigenin-labeled probe was used for all other viruses. HPV, EBV, and PVB19 were not detected in cases or controls. Two cases of GCH and 1 case of BA were PCR positive for CMV; controls were negative. HHV6 was detected in 6 cases: 2 GCH, 2 BA, and 2 controls. We conclude that HPV is not associated with GCH or BA. Detection of CMV in BA and GCH confirms other reports of this association. HHV6 requires further study to determine the significance of a positive PCR test in the livers of infants.

Unusual bone marrow manifestations of parvovirus B19 infection in immunocompromised patients

Parvovirus B19 is responsible for a spectrum of disease in humans. The usual bone marrow findings in acute parvovirus infections are marked erythroid hypoplasia and occasional giant erythroblasts. Intranuclear inclusions in developing erythroid precursors are rarely described in children or adults with parvovirus infection, although abundant intranuclear inclusions are commonly observed in the placenta and other tissues in infected fetuses. In this study, 8 patients are reported in whom the first evidence of parvovirus infection was the recognition of numerous intranuclear inclusions in erythroid precursors on bone marrow biopsy sections. Six of the 8 patients had documented immunodeficiencies; 4 had acquired immune deficiency syndrome (AIDS), and 2 were on chemotherapy. Five of 7 patients were negative for immunoglobulin G (IgG) antiparvovirus antibodies, including all 4 with AIDS. Unlike the typical pattern in parvovirus infection, the bone marrow was hypercellular in most of the patients, and erythroid precursors were usually increased with the entire spectrum of normoblast maturation represented; abundant intranuclear inclusions were observed similar to the finding in fetuses. The inclusions were variably eosinophilic and compressed the chromatin against the nuclear membrane. In situ hybridization showed parvovirus B19 DNA in numerous erythroid precursors in all cases. The findings of erythroid maturation and abundant viral inclusions in these immunocompromised patients is consistent with the hypothesis that failure to produce effective IgG parvovirus neutralizing antibodies may lead to persistent infection through viral tolerance that allows erythroid development of infected cells past the pronormoblast stage. Identification of parvovirus inclusions in marrow biopsies and subsequent confirmation of infection by in situ hybridization can be important in the assessment of anemia in immunodeficient patients because serological studies for parvovirus B19 are frequently negative.

In utero development of hypertensive necrotizing pulmonary arterial lesions: report of a case associated with premature closure of the ductus arteriosus and pulmonary hypoplasia

Premature closure of the ductus arteriosus (PCDA) is an uncommon defect in which pulmonary hypertension (PH) has been documented by echocardiography in patients and by direct measurement after experimental PCDA in animals. The pulmonary vascular histology in human cases has received little attention but in the few recorded observations the vessels were either normal or showed increased muscularity. We report the case of a 31 week hydropic female stillborn monozygotic twin in whom postmortem examination disclosed PCDA and hypoplasia of the lungs. Atypical plexiform lesions with necrotizing pulmonary arteritis were present. These lesions represent vascular consequences of severe pulmonary hypertension produced by greatly enhanced blood flow through a restricted vascular bed resulting from the combined effects of these two abnormalities. The findings in this case of PCDA with presumed severe PH indicate that severe pulmonary vascular changes can develop in utero and that the interval of time needed for development of such chances in secondary PH is relatively short.

Molecular abnormalities associated with secretory carcinomas of the breast

Secretory carcinomas (SCAs) represent a unique histological variant of invasive breast carcinomas, occurring predominantly in patients younger than 30 years of age. Data from limited series have shown SCAs to have a favorable prognosis in patients younger than 20 years of age, whereas the clinical course tends to parallel the more common in filtrating ductal carcinomas (IDCs) in patients older than 20 years. There are no reports on the molecular abnormalities associated with this unusual tumor. Microdissected archival formalin-fixed tissue from 10 SCAs collected from 2 institutions were used to determine the frequencies of allelic loss at 13 chromosomal regions with 19 microsatellite markers, using multiplex polymerase chain reaction (PCR)-based techniques. The results of loss of heterozygosity (LOH) and microsatellite alterations (MAs) analyses were compared with 20 cases of IDCs. P53 gene mutation analysis was also performed on the 10 SCAs using single-strand conformation polymorphism (SSCP) analysis, followed by sequencing of abnormal bands. LOH at multiple regions of chromosome 3p were the most common abnormality in both SCAs (55%) and IDCs (50%), followed by LOH at 17q21 (BRCA1 locus), 13q14 (retinoblastoma gene locus), and 8p21-23. No significant differences were seen in the frequencies of LOH at any chromosomal region except for 17p13 (p53 gene locus), where allelic losses were absent in SCAs, but evident in 46% of IDCs (P < .05). The 2 histological entities were similar in the fractional regional loss (FRL) index (0.26 v 0.24), fractional allelic loss (FAL) index (0.23 v 0.27), as well as in the frequency of MAs (0.015 v 0.005), P > .05. P53 gene missense mutation (G:C::A:T) was detected in 1 of 10(10%) SCAs. Based on the considerable similarities in the molecular abnormalities associated with both tumors, the formation of secondary lumina in both the in situ and the invasive components, as well as suggestions from limited series that the clinical behavior in adult patients parallels that of IDCs, SCA most likely reflects a secretory variant of IDCs.

Quantitation of 8 human herpesviruses in peripheral blood of human immunodeficiency virus-infected patients and healthy blood donors by polymerase chain reaction

Human herpesviruses are associated with morbidity and mortality in persons with compromised immune systems, including patients infected with human immunodeficiency virus (HIV). To investigate the basis for this association, the levels of all 8 human herpesviruses (herpes simplex virus, types 1 and 2, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, and human herpesvirus 6, human herpesvirus 7, and human herpesvirus 8) were measured with the quantitative polymerase chain reaction (PCR). Viral DNA was measured in the whole blood of 20 HIV-infected patients and compared with levels in 20 healthy blood donors. There was no significant difference in the frequency of virus detection of the 8 human herpesviruses between HIV-infected patients and healthy adults. These results indicate that HIV infection is not associated with a general increase in the circulating levels of human herpesviruses, and suggest that quantitative PCR analysis is superior to qualitative PCR analysis for detection of clinically relevant disease in HIV-infected patients.

Epidural analgesia and intrapartum fever: placental findings

OBJECTIVE

To assess whether epidural analgesia is associated with fever, independent of maternal infection, by evaluating the relationship between epidural analgesia and inflammation of the placenta.

METHODS

Placentas collected prospectively from women with singleton gestations, who delivered 6 hours or more after membrane rupture, were evaluated systematically for histologic inflammation by an investigator blinded to all clinical information. Maternal and neonatal markers of infection were assessed in the cohorts who did and did not receive epidural analgesia.

RESULTS

One hundred forty-nine consecutive placentas were analyzed, and 80 (54%) of these women received epidural analgesia. On univariate analysis, significant differences between epidural and no epidural groups were found with respect to maternal fever 38C or greater (46% versus 26%, P = .01), placenta inflammation (61% versus 36%, P = .002), and length of labor (11.8 hours versus 9.6 hours, P = .03). The combination of maternal fever plus placental inflammation was significantly more common in the epidural group (35% versus 17% P = .02). However, maternal fever in the absence of supporting evidence of infection, in the form of placental inflammation, was not increased after epidural analgesia (11% versus 9%, P = .61).

CONCLUSION

Epidural analgesia is associated with intrapartum fever, but only in the presence of placental inflammation. This suggests that the fever reported with epidural analgesia is due to infection rather than the analgesia itself.

Atherosis revisited: current concepts on the pathophysiology of implantation site disorders

There are two distinct histological manifestations of impaired placental implantation in humans--incomplete trophoblastic vascular invasion and atherosis. Both have been described to occur in pregnancies affected by a variety of disorders such as preeclampsia, fetal growth restriction, systemic lupus erythematosus, and diabetes. Our purpose was to integrate recent developments in the understanding of implantation site disorders into a pathophysiological scenario that interrelates these placentation disorders and associated pregnancy complications. Sources were identified from a MEDLINE search of English-language articles published from 1966 to 1997. Additional sources were identified from references cited in relevant reports. We selected articles relating to the following topics: atherosis, implantation site disorders, trophoblastic invasion, preeclampsia, fetal growth restriction, implantation site development, atherosclerosis, and endothelial activation-damage. A contemporary version of normal placentation, including vascular adaptation, was reviewed with comments on normal trophoblastic differentiation and vascular invasion. Specific abnormalities of the implantation site, including atherosis and incomplete trophoblastic invasion, were discussed in the context of placental site hypoperfusion and the association with pregnancy complications. It was concluded that atherosis and incomplete trophoblastic invasion may be both a consequence and a cause of placental site hypoperfusion resulting in the development of preeclampsia and a variety of other pregnancy disorders.

Human herpesvirus-6 and sudden death in infancy: report of a case and review of the literature

Investigation of sudden death in infancy is a vital function of the medical examiner's office. Surveillance of these cases may lead to recognition of new diseases or new manifestations of previously described diseases. Human herpesvirus-6 (HHV-6) is a relatively newly described virus that has been recognized as a cause of acute febrile illness in early childhood. While most cases are apparently self-limited, seven fatal cases have been reported. We present a case of a seven-month-old Latin American male with recent otitis media and vomiting who was found dead in bed. Autopsy revealed interstitial pneumonitis with an atypical polymorphous lymphocytic infiltrate in the liver, kidney, heart, spleen, lymph nodes, and bone marrow, associated with erythrophagocytosis. Polymerase chain reaction (PCR) analysis of formalin-fixed paraffin-embedded tissue was positive for HHV-6 and negative for Epstein-Barr virus (EBV) and cytomegalovirus (CMV). HHV-6 was also detected in the atypical lymphoid infiltrate by in-situ hybridization.