Prevalence of viral infection markers by polymerase chain reaction amplification and interferon-alpha measurements among patients undergoing lumbar puncture in an emergency department

Optimal combination of early biomarkers for infection and sepsis diagnosis in the emergency department: The BIPS study

OBJECTIVE

To define the best combination of biomarkers for the diagnosis of infection and sepsis in the emergency room.

METHODS

In this prospective study, consecutive patients with a suspicion of infection in the emergency room were included. Eighteen different biomarkers measured in plasma, and twelve biomarkers measured on monocytes, neutrophils, B and T-lymphocytes were studied and the best combinations determined by a gradient tree boosting approach.

RESULTS

Overall, 291 patients were included and analysed, 148 with bacterial infection, and 47 with viral infection. The best biomarker combination which first allowed the diagnosis of bacterial infection, included HLA-DR (human leukocyte antigen DR) on monocytes, MerTk (Myeloid-epithelial-reproductive tyrosine kinase) on neutrophils and plasma metaloproteinase-8 (MMP8) with an area under the curve (AUC) = 0.94 [95% confidence interval (IC95): 0.91;0.97]. Among patients in whom a bacterial infection was excluded, the combination of CD64 expression, and CD24 on neutrophils and CX3CR1 on monocytes ended to an AUC = 0.98 [0.96;1] to define those with a viral infection.

CONCLUSION

In a convenient cohort of patients admitted with a suspicion of infection, two different combinations of plasma and cell surface biomarkers were performant to identify bacterial and viral infection.

Monitoring Disease Activity in Systemic Lupus Erythematosus With Single-Molecule Array Digital Enzyme-Linked Immunosorbent Assay Quantification of Serum Interferon-α

OBJECTIVE

No simple or standardized assay is available to quantify interferon-α (IFNα) in routine clinical practice. Single-molecule array (Simoa) digital enzyme-linked immunosorbent assay (ELISA) technology enables direct IFNα quantification at attomolar (femtogram per milliliter [fg/ml]) concentrations. This study was undertaken to assess IFNα digital ELISA diagnostic performances to monitor systemic lupus erythematosus (SLE) activity.

METHODS

IFNα concentrations in serum samples from 150 consecutive SLE patients in a cross-sectional study were determined with digital ELISA and a functional biologic activity assay (bioassay). According to their Safety of Estrogens in Lupus Erythematosus National Assessment version of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) flare composite scores, patients were divided into groups with inactive SLE (SLEDAI score of <4 or clinical SLEDAI score of 0) or active SLE (SLEDAI score of ≥4 or clinical SLEDAI score of >0), and into groups with no flare or mild/moderate flare or severe flare.

RESULTS

Based on serum samples from healthy blood donors, the abnormal serum IFNα level threshold value was 136 fg/ml. Next, using receiver operating characteristic curves for an SLE patient series that was widely heterogeneous in terms of disease activity and organ involvement, the threshold IFNα value associated with active disease was determined to be 266 fg/ml. The digital ELISA-assessed serum IFNα level was a better biomarker of disease activity than the Farr assay because its specificity, likelihood ratio for positive results, and positive predictive value better discerned active SLE or flare from inactive disease. The digital ELISA was more sensitive than the bioassay for detecting low-abnormal serum IFNα concentrations and identifying patients with low disease activity.

CONCLUSION

Direct serum IFNα determination with a highly sensitive assay might improve monitoring of clinical SLE activity and selection of the best candidates for anti-IFNα treatment.

Viral meningitis: current issues in diagnosis and treatment

PURPOSE OF REVIEW

The purpose of this review is to give an overview of viral meningitis and then focus in on some of the areas of uncertainty in diagnostics, treatment and outcome.

RECENT FINDINGS

Bacterial meningitis has been declining in incidence over recent years. Over a similar time period molecular diagnostics have increasingly been used. Because of both of these developments viral meningitis is becoming relatively more important. However, there are still many unanswered questions. Despite improvements in diagnostics many laboratories do not use molecular methods and even when they are used many cases still remain without a proven viral aetiology identified. There are also no established treatments for viral meningitis and the one potential treatment, aciclovir, which is effective in vitro for herpes simplex virus, has never been subjected to a clinical trial.

SUMMARY

Viruses are in increasingly important cause of meningitis in the era of declining bacterial disease. The exact viral aetiology varies according to age and country. Molecular diagnostics can not only improve the rate of pathogen detection but also reduce unnecessary antibiotics use and length of hospitalization. Further research is required into treatments for viral meningitis and the impact in terms of longer term sequelae.

[Clinical, epidemiological and etiological studies of adult aseptic meningitis: Report of 11 cases with varicella zoster virus meningitis]

We treated 11 cases (52.7 ± 14.9 years, all male) with varicella zoster virus (VZV) meningitis and 437 cases with adult aseptic meningitis from 2004 to 2016. The incidence rate of adult VZV meningitis in the cases with aseptic meningitis was 2.5%. Herpes zoster infections are reported to have occurred frequently in summer and autumn. VZV meningitis also occurred frequently in the similar seasons, in our patients. The diagnoses were confirmed in 9 cases with positive VZV-DNA in the cerebrospinal fluid and in 2 cases with high VZV-IgG indexes (> 2.0). For diagnosis confirmation, the former test was useful for cases within a week of disease onset, and the latter index was useful for cases after a week of disease onset. Zoster preceded the meningitis in 8 cases, while the meningitis preceded zoster in 1 case, and 2 cases did not have zoster (zoster sine herpete). Two patients were carriers of the hepatitis B virus, 1 patient was administered an influenza vaccine 4 days before the onset of meningitis, and 1 patient was orally administered prednisolone for 2 years, for treatment. Their immunological activities might have been suppressed. The neurological complications included trigeminal neuralgia, facial palsy (Ramsay Hunt syndrome), glossopharyngeal neuralgia, and Elsberg syndrome. Because the diseases in some patients can become severe, they require careful treatment.

[Aseptic meningitis in an adult population. Etiology and utility of molecular techniques in the clinical management of patients]

OBJECTIVE

This study describes the epidemiological, clinical and microbiological features of acute aseptic meningitis (AAM) in an adult population, and evaluates the impact of microbiological results on the clinical management of patients.

PATIENTS AND METHODS

Cases of AAM were prospectively collected between 2007 and 2010 among immunocompetent patients over 14 years-old. Enteroviruses and herpes viruses were determined using nucleic acids detection in CSF. Demographic and clinical data were retrospectively collected from medical records.

RESULTS

A total of 94 patients were included, of whom 84 were diagnosed with viral meningitis (VM). The annual incidence of VM ranged from 2.4 to 15.3 cases per 100,000 inhabitants. An aetiological diagnosis was obtained in 76.2% of the patients with VM, 55 enterovirus, 4 HSV-2, 3 VZV, one HSV-1, and one EBV. Forty five per cent of patients were admitted to hospital and 65.8% of them received antibiotic treatment. A positive result prompted immediate discharge of 80% of inpatients and discontinuation of antibiotic therapy in 94.1% of them. The median duration of admission to hospital in these patients was 2.8±2.9 days. Patients without available results during admission completed the antibiotic treatment, and the median hospital stay was 11.6±4.6 days.

CONCLUSIONS

The annual incidence of AAM is variable. Enteroviruses were the main aetiological agent. Molecular tests revealed the aetiology in 76.2% of cases. Almost half of the patients required hospitalisation, and in these cases a positive result can lead to the immediate discharge of patients, and the diagnostic and therapeutic interventions can be reduced.

Varicella zoster virus meningitis with hypoglycorrhachia in the absence of rash in an immunocompetent woman

We report varicella-zoster virus (VZV) meningitis in a healthy adult woman with no antecedent rash and with hypoglycorrhachia. Cerebrospinal fluid (CSF) examination revealed the presence of VZV DNA, anti-VZV immunoglobulin G (IgG) antibody, and intrathecal production of anti-VZV IgG antibody.

Aseptic meningitis caused by reactivation of varicella-zoster virus in two immunocompetent patients

Varicella-zoster virus (VZV) may be a more frequent causative factor of aseptic meningitis than previously anticipated. Here we present 2 cases of reactivation of VZV in immunocompetent individuals, resulting in meningitis and affection of multiple cranial nerves, and discuss the incidence, clinical spectrum, pathogenesis, diagnostics and options for treatment.

Identifying low-risk patients for bacterial meningitis in adult patients with acute meningitis

OBJECTIVE

To derive and validate a clinical prediction model with high sensitivity for differentiating aseptic meningitis (AM) patients from bacterial meningitis (BM) patients.

METHODS

We developed the model using the derivation cohort in a community rural hospital in Okinawa and assessed its performance using the validation cohort in a metropolitan urban hospital in Tokyo. There were 66 (39.5%) and 5 (17.9%) adult patients with BM among the derivation (n=167) and the validation cohort (n=28), respectively. Recursive partitioning analysis was used to determine the important classification variables and to develop a sensitive model to safely exclude BM.

RESULTS

The model produced high- and low-risk groups based on the following: 1) Gram stain, 2) CSF neutrophil percent < or =15%, 3) CSF neutrophil count < or =150 cells/mm(3), and, 4) mental status change. Among the derivation cohort, there were 65 patients with BM in the high-risk group (n=76), while only one patient with BM was noted (sensitivity, 99%) in the low-risk group (n=91). Among the validation cohort, there were 5 patients with BM in the high-risk group (n=7), while no patient was classified with BM (sensitivity, 100%) in the low-risk group (n=21).

CONCLUSION

This simple and sensitive model might be useful to safely identify low-risk patients for BM who would not require antibiotic treatment.

Herpes zoster and meningitis resulting from reactivation of varicella vaccine virus in an immunocompetent child

Herpes zoster complicated by meningitis has been mainly reported in immunocompromised patients after reactivation of wild-type varicella-zoster virus. We present one of the first cases of aseptic meningitis after herpes zoster caused by reactivation of vaccine-type varicella-zoster virus in an immunocompetent child. We also highlight the increasing role of both wild-type and vaccine strains of varicella-zoster virus as a cause of viral meningoencephalitis and the use of appropriate laboratory tools to rapidly and accurately identify the virus in order to provide prompt patient care and management.

Progressive multifocal leukoencephalopathy – the importance of early diagnosis illustrated in four cases

Progressive multifocal leukoencephalopathy (PML) is a rare, deadly demyelinating disease of the central nervous system, which is caused by a reactivation of the DNA polyomavirus JC and occurs in immunosuppressed individuals. So far, only 25 cases have been described in patients with SLE and none survived without antiviral therapy and only two cases in RA. We present four additional cases from a defined area, three in SLE, of which one survived without antiviral therapy, and one case in RA, also surviving after reduction of immunosuppressive treatment. In three of these cases, diagnosis could only be confirmed by stereotactical brain biopsy, including the two surviving cases. Thus, this article illustrates the difficulty in diagnosing progressive multifocal leukoencephalopathy, the need for brain biopsy in many cases, the importance of reduced immunosuppression as early as possible and the severe damage progressive multifocal leukoencephalopathy can cause. Furthermore, progressive multifocal leukoencephalopathy might be much more common in SLE than expected with 1 case in 800 patient-years.

Accuracy of the cerebrospinal fluid results to differentiate bacterial from non bacterial meningitis, in case of negative gram-stained smear

OBJECTIVE

The aim of this study was to evaluate the usefulness of various laboratory results for differential diagnosis of bacterial (BM) and nonbacterial meningitis (NBM) with negative initial Gram stain.

DESIGN AND SETTING

A prospective multicenter study was conducted in the emergency departments of 3 teaching hospitals.

PARTICIPANTS AND METHODS

Consecutive adult patients with a diagnosis of meningitis based on compatible clinical features and cerebrospinal fluid (CSF) culture findings with a CSF leukocyte count greater than 5/mm(3) were included in the study. Symptoms, examination findings, data from laboratory results, including CSF results and serum C-reactive protein (CRP) levels, and clinical outcome were assessed.

RESULTS

One hundred fifty-one patients (age, 35 +/- 15 years) with confirmed meningitis were admitted: 133 with NBM and 18 with BM. CRP and procalcitonin (PCT) levels, CSF white cell and absolute neutrophil counts, and CSF glucose/blood glucose and CSF protein levels were significantly higher in the BM group. However, as diagnostic indicators of BM, none of these variables except PCT was more efficient than that of the emergency physician. Values of the area under the receiver operating characteristic curve were 0.59 (95% confidence interval [CI], 0.21-0.82), 0.79 (95% CI, 0.47-0.92), 0.18 (95% CI, 0.0-0.43), 0.70 (95%CI, 0.30-0.89), 0.81 (95% CI, 0.58-0.92), and 0.98 (95% CI, 0.83-1.0) for CSF leukocyte count, percentage of CSF leukocyte, CSF/blood glucose ratio, CSF protein level, serum CRP, and serum PCT (P < .05 vs CRP), respectively.

CONCLUSION

CSF results have a modest role in distinguishing BM from NBM in a negative Gram stain for bacteria. PCT serum levels seem to be an excellent predictor of BM.

Main adult herpes virus infections of the CNS

Herpes viruses are widely involved in human infectious diseases, and some are life threatening, such as CNS infections. These manifestations vary according to the type of virus involved and the immune status of the patient. This article will review the clinical manifestations (encephalitis, myelitis, meningitis and postinfectious encephalomyelitis), the diagnostic strategies and the presently used drugs (acyclovir, valacyclovir, ganciclovir, valgancyclovir, foscarnet and cidofovir). The review will also discuss drugs that are currently in the pipeline and that could be used in the future.

Does serum alpha interferon measurement aid in the etiological diagnosis of febrile adult patients?

In febrile patients, distinguishing bacterial from viral infections is crucial for early treatment initiation and rational use of antibiotics. Raised interferon-alpha (IFN-alpha) levels in serum has been associated with a wide range of viral infections. We evaluated the effectiveness of IFN-alpha serum measurements for the etiological diagnosis of febrile patients. Adult patients who were attending the emergency department with body temperature above or equal to 38.5 degrees C were studied prospectively, followed-up until day 30, and classified by two independent experts (blind for IFN-alpha results) as having a bacterial/parasitic infection, viral infection, or other diagnosis. The results of IFN-alpha measurements in blood samples taken in the emergency room, were compared with expert diagnosis. Among 243 patients included, 167 had bacterial/parasitic infections (including 19 with viral co-infection), 59 had viral infections, and 36 other diagnoses. IFN-alpha assay had a sensitivity of 0.44 and a specificity of 0.92 for the diagnosis of viral infection. Among the 20 patients with acute viral infection according to the emergency physician diagnosis, 7 (35%) were given antibiotics, including four patients with raised IFN-alpha concentrations. It is concluded that in febrile patients, raised serum IFN-alpha level is highly specific of the viral etiology of fever but poorly sensitive. Reliable viral and bacterial biological markers are needed in order to improve rational use of antibiotics.

Comparative analysis of cytokine gene expression in cerebrospinal fluid of horses without neurologic signs or with selected neurologic disorders

OBJECTIVE

To determine gene transcription for cytokines in nucleated cells in CSF of horses without neurologic signs or with cervical stenotic myelopathy (CSM), West Nile virus (WNV) encephalitis, equine protozoal myeloencephalitis (EPM), or spinal cord trauma.

ANIMALS

41 horses (no neurologic signs [n = 12], CSM [8], WNV encephalitis [9], EPM [6], and spinal cord trauma [6]).

PROCEDURES

Total RNA was extracted from nucleated cells and converted into cDNA. Gene expression was measured by use of real-time PCR assay and final quantitation via the comparative threshold cycle method.

RESULTS

Cytokine genes expressed by nucleated cells of horses without neurologic signs comprised a balance between proinflammatory tumor necrosis factor-alpha (TNF-alpha), anti-inflammatory cytokines (interleukin [IL]-10 and transforming growth factor [TGF]-beta), and Th1 mediators (interferon [IFN]-gamma). Cells of horses with CSM mainly expressed genes for TNF-alpha, TGF-beta, and IL-10. Cells of horses with WNV encephalitis mainly expressed genes for IL-6 and TGF-beta. Cells of horses with EPM mainly had expression of genes for IL-6, IL-8, IL-10, TNF-alpha, IFN-gamma, and TGF-beta. Cells from horses with spinal cord trauma had expression mainly for IL-6; IFN-gamma; TGF-beta; and less frequently, IL-2, IL-10, and TNF-alpha. Interleukin-8 gene expression was only detected in CSF of horses with infectious diseases.

CONCLUSIONS AND CLINICAL RELEVANCE

Despite the small number of CSF samples for each group, results suggest distinct gene signatures expressed by nucleated cells in the CSF of horses without neurologic signs versus horses with inflammatory or traumatic neurologic disorders.

Interferon-alpha prevents apoptosis of endothelial cells after short-term exposure but induces replicative senescence after continuous stimulation

Although the antiangiogenic activity of type I interferons (IFN) is well known, the mechanism by which it occurs is unclear. In the present study, we have investigated effects of short-term and long-term IFN-alpha exposure on different types of endothelial cells (EC). Short-term IFN-alpha treatment resulted in a distinct reduction of apoptosis of serum and growth factor starved HUVEC and HDMEC. This was accompanied by a strong upregulation of the IFN inducible guanylate binding protein-1 (GBP-1) whereas no consistent regulation of several known antiapoptotic proteins was evident. Stable transfection of HUVEC with an expression vector for GBP-1 mimicked the protective effect of IFN-alpha, suggesting that GBP-1 may contribute to the inhibition of apoptosis. When IFN-alpha, together with serum and EC growth factors, was present continuously a decrease of population doublings by more than 40% was observed in both HDMEC and HCAEC. In addition, the cells displayed a senescent phenotype significantly earlier than control cells and showed an increased adherence for monocytes. Our findings suggest that the antiangiogenic effect of IFN-alpha is mediated by inducing EC senescence rather than EC apoptosis. Furthermore IFN-alpha released in chronic inflammatory conditions might contribute via its prosenescent activity to the pathogenesis of atherosclerosis.

Neurologic aspects of infections in international travelers

BACKGROUND

As international travel for business and pleasure becomes part of contemporary lifestyle, the clinician today is confronted with an increasing number of travelers returning ill with unfamiliar syndromes. The physician will encounter a myriad of patients with exotic infections, emerging infectious diseases, or resurgent Old-World infections.

REVIEW SUMMARY

This review article will discuss salient points of important infectious diseases associated with overseas travel, provide a syndromic approach to the traveler who returns with neurologic manifestations, and list resources for additional diagnostic, therapeutic, and preventive information.

CONCLUSIONS

As many of infections acquired in other countries can directly or indirectly affect the nervous system, the care of the ill traveler often falls into the hands of neurologists. The contemporary neurologist should therefore be knowledgeable of the clinical manifestations, potential complications, and appropriate management of region-specific infections.