Establishing correlates of maternal-fetal cytomegalovirus transmission-one step closer through predictive modeling.

BACKGROUND: Determinants of maternal-fetal cytomegalovirus (CMV) transmission and factors influencing the severity of congenital CMV (cCMV) infection are not well understood. METHODS: We conducted a descriptive, multi-center study in pregnant women ≥18 years old with primary CMV infection and their newborns (NCT01251744) to explore maternal immune responses to CMV and determine potential immunologic/virologic correlates of cCMV following primary infection during pregnancy. We developed alternative approaches looking into univariate/multivariate factors associated with cCMV, including a participant clustering/stratification approach and an interpretable predictive model-based approach using trained decision trees for risk prediction (post-hoc analyses). RESULTS: Pregnant women were grouped in three distinct clusters with similar baseline characteristics, particularly gestational age at diagnosis. We observed a trend for higher viral loads in urine and saliva samples from mothers of infants with cCMV versus without cCMV. When using a trained predictive-model approach that accounts for interaction effects between variables, anti-pentamer IgG antibody concentration and viral load in saliva were identified as biomarkers jointly associated with the risk of maternal-fetal CMV transmission. CONCLUSION: We identified biomarkers of CMV maternal-fetal transmission. After validation in larger studies, our findings will guide the management of primary infection during pregnancy and the development of vaccines against cCMV.

The human cytomegalovirus (CMV) is common and usually causes no symptoms in healthy individuals. However, CMV infections can be life-threatening in individuals with improperly functioning or immature immune systems, such as fetuses. Women can become infected with CMV for the first time (primary infection) during pregnancy. If CMV is transmitted from mother to fetus before the second trimester, the infant can suffer from severe disorders such as hearing loss and delayed development. We aimed to identify characteristics of pregnant women with a primary CMV infection that may increase the likelihood of transmitting CMV to the fetus. We considered demographical, clinical, and behavioral characteristics, as well as immune responses and the quantity of virus detected in the women's blood, urine, saliva, and vaginal mucus. Because we could not identify one single characteristic that could predict a high risk of CMV transmission, we developed new data analysis models to study how they can be combined. We found that antibodies targeting a pentameric antigen of the virus envelope and the presence of virus in saliva can together predict the risk of CMV transmission from mother to fetus. Our results can help improve the care of CMV-infected pregnant women and the design of CMV vaccines.

Incidence of Cytomegalovirus Primary and Secondary Infection in Adolescent Girls: Results From a Prospective Study.

Developing a vaccine to prevent congenital cytomegalovirus (CMV) infection and newborn disability requires an understanding of infection incidence. In a prospective cohort study of 363 adolescent girls (NCT01691820), CMV serostatus, primary infection, and secondary infection were determined in blood and urine samples collected at enrollment and every 4 months for 3 years. Baseline CMV seroprevalence was 58%. Primary infection occurred in 14.8% of seronegative girls. Among seropositive girls, 5.9% had ≥4-fold increase in anti-CMV antibody, and 23.9% shed CMV DNA in urine. Our findings provide insights on infection epidemiology and highlight the need for more standardized markers of secondary infection.

Cytomegalovirus (CMV) can be passed from a woman to her unborn baby during pregnancy, which can result in disabilities in the baby. This can happen after a first infection with the virus during pregnancy, after a subsequent infection with a different strain ("reinfection"), or after "reactivation", which means that a virus present from a previous infection becomes active again. Vaccinating adolescent girls against CMV may be a future strategy to help prevent CMV infection during pregnancy. To provide information to design trials evaluating a CMV vaccine, it is important to know how common primary/secondary CMV infection is in adolescent girls and if this can be measured with available tools. We followed adolescent girls living in Finland, Mexico or the United States for three years. At study start, 58% of these girls showed evidence of previous CMV infection. During the three-year follow-up, a first CMV infection occurred in 15% of girls, and reinfection or reactivation in 6% to 24% of girls (depending on the method used). The obtained estimates of CMV infection rates in adolescent girls provide valuable information for future studies to evaluate CMV vaccines, but standardized markers for secondary infection are needed.

Cryptococcal meningitis is a cause for cross-reactivity in cerebrospinal fluid assays for anti-Histoplasma, anti-Coccidioides and anti-Blastomyces antibodies.

BACKGROUND/OBJECTIVES: Antibody detection is commonly used for diagnosis of histoplasmosis, and cross-reactions have been recognised due to endemic mycoses but not cryptococcosis. We observed cross-reactions in an anti-Histoplasma antibody enzyme immunoassay (EIA) in the cerebrospinal fluid (CSF) from a patient with cryptococcal meningitis and sought to assess the risk of cross-reactive anti-Histoplasma antibodies in persons with cryptococcal meningitis. METHODS: An anti-cryptococcal antibody EIA was developed to measure CSF antibody response in HIV-infected subjects from Kampala, Uganda and previously healthy, HIV-negative subjects at the National Institutes of Health (NIH) with cryptococcal meningitis. Specimens were tested for cross-reactivity in assays for IgG anti-Histoplasma, anti-Blastomyces and anti-Coccidioides antibodies. RESULTS: Among 61 subjects with cryptococcal meningitis (44 Kampala cohort, 17 NIH cohort), elevated CSF anti-cryptococcal antibody levels existed in 38% (23/61). Of the 23 CSF specimens containing elevated anti-cryptococcal antibodies, falsely positive results were detected in antibody EIAs for histoplasmosis (8/23, 35%), coccidioidomycosis (6/23, 26%) and blastomycosis (1/23, 4%). Overall, 2% (2/81) of control CSF specimens had elevated anti-cryptococcal antibody detected, both from Indiana. CONCLUSIONS: Cryptococcal meningitis may cause false-positive results in the CSF for antibodies against Histoplasma, Blastomyces and Coccidioides. Fungal antigen testing should be performed to aid in differentiating true- and false-positive antibody results in the CSF.

Spinal Arachnoiditis as a Complication of Cryptococcal Meningoencephalitis in Non-HIV Previously Healthy Adults.

BACKGROUND: Cryptococcus can cause meningoencephalitis (CM) among previously healthy non-HIV adults. Spinal arachnoiditis is under-recognized, since diagnosis is difficult with concomitant central nervous system (CNS) pathology. METHODS: We describe 6 cases of spinal arachnoiditis among 26 consecutively recruited CM patients with normal CD4 counts who achieved microbiologic control. We performed detailed neurological exams, cerebrospinal fluid (CSF) immunophenotyping and biomarker analysis before and after adjunctive immunomodulatory intervention with high dose pulse corticosteroids, affording causal inference into pathophysiology. RESULTS: All 6 exhibited severe lower motor neuron involvement in addition to cognitive changes and gait disturbances from meningoencephalitis. Spinal involvement was associated with asymmetric weakness and urinary retention. Diagnostic specificity was improved by MRI imaging which demonstrated lumbar spinal nerve root enhancement and clumping or lesions. Despite negative fungal cultures, CSF inflammatory biomarkers, sCD27 and sCD21, as well as the neuronal damage biomarker, neurofilament light chain (NFL), were elevated compared to healthy donor (HD) controls. Elevations in these biomarkers were associated with clinical symptoms and showed improvement with adjunctive high dose pulse corticosteroids. CONCLUSIONS: These data suggest that a post-infectious spinal arachnoiditis is an important complication of CM in previously healthy individuals, requiring heightened clinician awareness. Despite microbiological control, this syndrome causes significant pathology likely due to increased inflammation and may be amenable to suppressive therapeutics.

Paradoxical Immune Responses in Non-HIV Cryptococcal Meningitis.

The fungus Cryptococcus is a major cause of meningoencephalitis in HIV-infected as well as HIV-uninfected individuals with mortalities in developed countries of 20% and 30%, respectively. In HIV-related disease, defects in T-cell immunity are paramount, whereas there is little understanding of mechanisms of susceptibility in non-HIV related disease, especially that occurring in previously healthy adults. The present description is the first detailed immunological study of non-HIV-infected patients including those with severe central nervous system (s-CNS) disease to 1) identify mechanisms of susceptibility as well as 2) understand mechanisms underlying severe disease. Despite the expectation that, as in HIV, T-cell immunity would be deficient in such patients, cerebrospinal fluid (CSF) immunophenotyping, T-cell activation studies, soluble cytokine mapping and tissue cellular phenotyping demonstrated that patients with s-CNS disease had effective microbiological control, but displayed strong intrathecal expansion and activation of cells of both the innate and adaptive immunity including HLA-DR+ CD4+ and CD8+ cells and NK cells. These expanded CSF T cells were enriched for cryptococcal-antigen specific CD4+ cells and expressed high levels of IFN-γ as well as a lack of elevated CSF levels of typical T-cell specific Th2 cytokines -- IL-4 and IL-13. This inflammatory response was accompanied by elevated levels of CSF NFL, a marker of axonal damage, consistent with ongoing neurological damage. However, while tissue macrophage recruitment to the site of infection was intact, polarization studies of brain biopsy and autopsy specimens demonstrated an M2 macrophage polarization and poor phagocytosis of fungal cells. These studies thus expand the paradigm for cryptococcal disease susceptibility to include a prominent role for macrophage activation defects and suggest a spectrum of disease whereby severe neurological disease is characterized by immune-mediated host cell damage.

Performance of the Cryptococcal Antigen Lateral Flow Assay in Non-HIV-Related Cryptococcosis.

The cryptococcal antigen lateral flow assay (CrAg LFA) was evaluated for the diagnosis of cryptococcosis in HIV-negative patients. The sensitivity was excellent, suggesting that this assay can replace conventional testing based on latex agglutination (LA). CrAg LFA and LA titers were correlated but were not directly comparable, with implications for conversion between assays.

Cerebrospinal fluid markers reveal intrathecal inflammation in progressive multiple sclerosis.

OBJECTIVE: The management of complex patients with neuroimmunological diseases is hindered by an inability to reliably measure intrathecal inflammation. Currently implemented laboratory tests developed >40 years ago either are not dynamic or fail to capture low levels of central nervous system (CNS) inflammation. Therefore, we aimed to identify and validate biomarkers of CNS inflammation in 2 blinded, prospectively acquired cohorts of untreated patients with neuroimmunological diseases and embedded controls, with the ultimate goal of developing clinically useful tools. METHODS: Because biomarkers with maximum utility reflect immune phenotypes, we included an assessment of cell specificity in purified primary immune cells. Biomarkers were quantified by optimized electrochemiluminescent immunoassays. RESULTS: Among markers with cell-specific secretion, soluble CD27 is a validated biomarker of intrathecal T-cell activation, with an area under the receiver operating characteristic curve of 0.97. Comparing the quantities of cerebrospinal fluid (CSF) immune cells and their respective cell-specific soluble biomarkers (released by CSF cells as well as their counterparts in CNS tissue) provided invaluable information about stationary CNS immune responses, previously attainable via brain biopsy only. Unexpectedly, progressive and relapsing-remitting multiple sclerosis (MS) patients have comparable numbers of activated intrathecal T and B cells, which are preferentially embedded in CNS tissue in the former group. INTERPRETATION: The cell-specific biomarkers of intrathecal inflammation may improve diagnosis and management of neuroimmunological diseases and provide pharmacodynamic markers for future therapeutic developments in patients with intrathecal inflammation that is not captured by imaging, such as in progressive MS.

Enzyme immunoassay versus latex agglutination cryptococcal antigen assays in adults with non-HIV-related cryptococcosis.

We compared paired enzyme immunoassay (EIA) and latex agglutination (LA) assay results with 185 blood and 164 cerebrospinal fluid (CSF) samples from 44 and 33 non-HIV cryptococcosis patients, respectively. The LA assay cutoff of 1:256 in the blood and 1:32 in the CSF was most highly predictive of a positive EIA result. The EIA missed 18.4% detected by the LA assay in the blood samples and 7.8% detected by the LA assay in the CSF samples. We note here the improved sensitivity of the LA assay over the EIA in non-HIV patients.

Geoclimatic influences on invasive aspergillosis after hematopoietic stem cell transplantation.

BACKGROUND: Aspergillus species are ubiquitous. We hypothesized that climatic variables that affect airborne mold counts affect the incidence of invasive aspergillosis (IA). METHODS: Patients who received hematopoietic stem cell transplants (HSCTs) in geographically and climatically diverse regions (Seattle, WA, and Houston, TX) were examined. Cumulative incidence function, Kaplan-Meier analysis, and Cox proportional hazards regression were performed to examine the association between IA and season. Poisson regression analysis was performed to evaluate the seasonal patterns in IA rates and association with spore counts and climate. RESULTS: In Seattle, the 3-month incidence of IA was 4.6% (5.7% in allograft recipients and 0.8% in autograft recipients). During the 10-year study period, there was a decrease in the incidence of IA among allogeneic HSCT recipients, corresponding to decreased risks during the nonsummer months; receipt of HSCTs during the summer months was associated with an increased hazard for IA (hazard ratio, 1.87; 95% confidence interval, 1.25-2.81) after adjustment for other known risks. The person-month IA rate in Seattle was positively associated with environmental spore counts, which increased with high temperature and low precipitation. No seasonal effect on IA was observed in Houston, where total spore counts were lower and not variable by climate. CONCLUSIONS: Climatic variables differentially affect airborne spore counts and IA risk in geographically disparate centers.

Spatio-temporal and healthcare trends of non-endemic, invasive fungal infections in the United States, National Hospital Discharge Survey--1996 to 2006.

Non-endemic, invasive fungal infections (IFI) remain a major cause of morbidity and mortality but their healthcare epidemiologic patterns require further elucidation. The 1996-2006 records in the National Hospital Discharge Survey (NHDS) of a hospitalized sub-cohort of HIV, hematologic malignancy, and transplant patients were analyzed. The objective was to determine independent predictors of non-endemic IFI, apart from other known predisposing host factors. Population-weighted, univariate analyses identified potential variables to include in multivariate models. Risk ratios for IFI using logistic regression and calculated incidence rate ratios (IRR) for IFI-associated mortality using a discrete, proportional hazards model were estimated. A total of 372 IFI hospital discharges, with a case-fatality proportion of 11.7% were identified. There was a significant trend toward increasing IFI hospitalizations (86.2%) in smaller hospitals (< 500 beds). Most IFIs occurred during the spring (37.6%, P = 0.01) and in the Midwest and South (41%) sections of the US, and lasted more than 7 days (61.7%, P < 0.0001). However, multivariable analysis revealed that the risk for IFI hospitalization was greatest during the autumn in the Midwest (RR=6.25 [1.57-24.9], P = 0.009) and in the Northeast (RR=8.14 [2.03-32.6], P = 0.003). Transfer from another healthcare facility conferred over a 3-fold increase risk (RR = 3.38 [2.30-4.97]) whereas a clinician referral reduced the risk by 36% (RR=0.64 [0.44-0.88]). The IFI-related mortality rate was least for the young, regardless of area and season (IRR(0-14years) = 0.155 [0.044-0.550]). Maintaining a steady rate over the past decade, non-endemic IFI hospitalizations exhibit a significant differential distribution in time and space. Prevention efforts that incorporate these trends may lessen IFI healthcare burden.

Audiologic and Otologic Complications of Cryptococcal Meningoencephalitis in Non-HIV Previously Healthy Patients.

OBJECTIVE: To identify audiologic and otologic outcomes in previously healthy non-HIV patients with cryptococcal meningoencephalitis (CM). STUDY DESIGN: Retrospective case review of a subset of patients recruited in a prospective observational study following previously healthy individuals who developed CM. SETTING: Tertiary referral center, National Institutes of Health Clinical Center. PATIENTS: Previously healthy adult patients with CM without immune suppressive therapy before disease onset. INTERVENTIONS: Diagnostic evaluations included audiometry, acoustic immittance, otoacoustic emissions, and auditory brainstem response studies, in addition to neurotologic assessment. RESULTS: Twenty-nine patients (58 years) underwent audiologic evaluation between 6 months and 3.5 years after CM diagnosis; 21 patients were seen for longitudinal assessment with an average duration of follow up of 20.3 months. Nearly three-quarters (73%) of the cohort presented with hearing loss, most commonly (90%) sensorineural in origin. The most frequent degree of loss was mild and then moderate, although some patients had severe or profound impairment. Hearing loss improved (43%) or remained stable (38%) in most cases. Ears with internal auditory canal enhancement on magnetic resonance imaging (MRI) had significantly more hearing loss than those without enhancement, although a similar finding was not observed with gyral enhancement or the presence of ependymitis or ventricular volume expansion. Hearing loss was not associated with reduced cerebrospinal fluid (CSF) glucose, CSF total protein, cryptococcal antigen, or total cell count. CONCLUSIONS: Hearing loss is a common manifestation of cryptococcal meningitis in previously healthy patients and may involve a cochlear or neural site of lesion, or both. Routine surveillance of hearing in patients is recommended, regardless of symptomatology, to ensure early and appropriate intervention and care.

Cryptococcal meningitis: epidemiology, immunology, diagnosis and therapy.

HIV-associated cryptococcal meningitis is by far the most common cause of adult meningitis in many areas of the world that have high HIV seroprevalence. In most areas in Sub-Saharan Africa, the incidence of cryptococcal meningitis is not decreasing despite availability of antiretroviral therapy, because of issues of adherence and retention in HIV care. In addition, cryptococcal meningitis in HIV-seronegative individuals is a substantial problem: the risk of cryptococcal infection is increased in transplant recipients and other individuals with defects in cell-mediated immunity, and cryptococcosis is also reported in the apparently immunocompetent. Despite therapy, mortality rates in these groups are high. Over the past 5 years, advances have been made in rapid point-of-care diagnosis and early detection of cryptococcal antigen in the blood. These advances have enabled development of screening and pre-emptive treatment strategies aimed at preventing the development of clinical infection in patients with late-stage HIV infection. Progress in optimizing antifungal combinations has been aided by evaluation of the clearance rate of infection by using serial quantitative cultures of cerebrospinal fluid (CSF). Measurement and management of raised CSF pressure, a common complication, is a vital component of care. In addition, we now better understand protective immune responses in HIV-associated cases, immunogenetic predisposition to infection, and the role of immune-mediated pathology in patients with non-HIV associated infection and in the context of HIV-associated immune reconstitution reactions.

Choroid Plexitis and Ependymitis by Magnetic Resonance Imaging are Biomarkers of Neuronal Damage and Inflammation in HIV-negative Cryptococcal Meningoencephalitis.

CNS cryptococcal meningoencephalitis in both HIV positive (HIV+) and HIV negative (HIV-) subjects is associated with high morbidity and mortality despite optimal antifungal therapy. We thus conducted a detailed analysis of the MR imaging findings in 45 HIV- and 11 HIV+ patients to identify imaging findings associated with refractory disease. Ventricular abnormalities, namely ependymitis and choroid plexitis were seen in HIV- but not in HIV+ subjects. We then correlated the imaging findings in a subset of HIV- subjects (n = 17) to CSF levels of neurofilament light chain (NFL), reflective of axonal damage and sCD27, known to best predict the presence of intrathecal T-cell mediated inflammation. We found that ependymitis on brain MRI was the best predictor of higher log(sCD27) levels and choroid plexitis was the best predictor of higher log(NFL) levels. The availability of predictive imaging biomarkers of inflammation and neurological damage in HIV- subjects with CNS cryptococcosis may help gauge disease severity and guide the therapeutic approach in those patients.

Susceptibility to Cryptococcal Meningoencephalitis Associated With Idiopathic CD4+ Lymphopenia and Secondary Germline or Acquired Defects.

Idiopathic CD4+ lymphopenia (ICL) predisposes to opportunistic infections (OIs) but can often remain asymptomatic and does not have a strong association with monogenic mutations. Likewise, cryptococcal meningoencephalitis, the most common OI in ICL, is not strongly associated with monogenic mutations. In this study, we describe 2 patients with ICL plus an additional immune defect: one from an E57K genetic mutation in the nuclear factor-κß essential modulator, and the other with acquired autoantibodies to granulocyte-macrophage colony-stimulating factor. Thus, these cases may exemplify a "multi-hit model" in patients with ICL who acquire OIs.

Combination Antifungal Therapy for Invasive Aspergillosis Revisited.

Invasive aspergillosis (IA) causes significant morbidity and mortality among immunocompromised hosts. Combination therapy with mold-active triazoles and echinocandins has been used with the hope of improving outcomes over monotherapy, especially in the setting of refractory disease. Herein, I update our prior systematic review and meta-analysis on combination therapy for salvage IA in the context of the recently published randomized clinical trial of combination therapy for primary IA. Clinicians should consider combination antifungals for IA in refractory disease despite immune reconstitution when there are concerns for resistance or pharmacokinetic variability.

Fighting the Monster: Applying the Host Damage Framework to Human Central Nervous System Infections.

The host damage-response framework states that microbial pathogenesis is a product of microbial virulence factors and collateral damage from host immune responses. Immune-mediated host damage is particularly important within the size-restricted central nervous system (CNS), where immune responses may exacerbate cerebral edema and neurological damage, leading to coma and death. In this review, we compare human host and therapeutic responses in representative nonviral generalized CNS infections that induce archetypal host damage responses: cryptococcal menigoencephalitis and tuberculous meningitis in HIV-infected and non-HIV-infected patients, pneumococcal meningitis, and cerebral malaria. Consideration of the underlying patterns of host responses provides critical insights into host damage and may suggest tailored adjunctive therapeutics to improve disease outcome.

Fungal Infections of the Central Nervous System.

PURPOSE OF REVIEW: This article summarizes current knowledge on the epidemiology, clinical presentations, diagnosis, and management of selected fungal infections of the central nervous system (CNS). Key syndromes, differential diagnoses, and therapeutic interventions according to host immune status and exposure are reviewed. RECENT FINDINGS: Advancements in imaging of the brain and spinal cord, and molecular DNA and antigen-based laboratory diagnostics afford improved sensitivity for CNS mycoses. Newer therapeutic strategies may improve outcomes if provided early and host immunosuppression is abrogated. Adjunctive corticosteroid use for disabling neuroinflammation and cerebral edema in the setting of microbiological control may be considered. In addition, nonspecific presentations and absence of fevers in patients without human immunodeficiency virus suggest that screening for Cryptococcus meningitis be performed in all patients with subcortical dementias using a simple CSF or serum antigen test. SUMMARY: CNS fungal infections comprise a wide spectrum of clinical syndromes, including abscesses, meningitis/meningoencephalitis, focal masses, stroke/vasculitides, immune reconstitution inflammatory syndrome (IRIS), and spinal pathologies such as arachnoiditis. The main etiologies include Aspergillus, Cryptococcus, Candida, Mucorales, dematiaceous molds, and dimorphic endemic fungi, with the route of acquisition being respiratory or traumatic inoculation with subsequent spread hematogenously or contiguously. Proper management focuses on early effective antifungal therapy and surgery for large or compressive mass lesions. While adjunctive recombinant cytokine or growth factor use has been supported in certain hosts with refractory infections, IRIS-like reactions may occur, suggesting alternative approaches such as high-dose pulse corticosteroids followed by taper.