Zika virus infection in pregnant travellers and impact on childhood neurodevelopment in the first two years of life: A prospective observational study.

BACKGROUND: The emergence of Zika virus (ZIKV) represents a threat with consequences on maternal and children's health. We aimed to assess the clinical and epidemiological characteristics of pregnant women returning from ZIKV affected areas, and the effects of maternal ZIKV infection on birth outcomes and children's health. METHODS: This was a hospital-based prospective observational study conducted at the Hospital Clínic of Barcelona and Hospital Sant Joan de Déu, Barcelona, Spain, from January 2016 to February 2020. RESULTS: One hundred and ninety-five pregnant women who had travelled to ZIKV affected areas during pregnancy were recruited. Four women (2.1%) had a confirmed ZIKV infection, 40 women (20.5%) a probable infection, and 151 (77.4%) were negative for ZIKV. Among the ZIKV confirmed cases, a pregnant woman suffered a miscarriage, highly plausible to be associated with ZIKV infection. Brain cysts and microcalcifications were detected in 7% of fetuses or infants from women with confirmed or probable ZIKV infection. Neurodevelopmental delay in the language function was found in 33.3% out of the 21 children evaluated. CONCLUSIONS: These findings contribute to the understanding of ZIKV prevalence estimates, and the impact of maternal ZIKV infection on pregnancy outcomes and children's health. Results highlight the importance of long-term surveillance in pregnant travellers and their children.

Identification of Immunological Parameters as Predictive Biomarkers of Relapse in Patients with Chronic Myeloid Leukemia on Treatment-Free Remission.

BCR-ABL is an aberrant tyrosine kinase responsible for chronic myeloid leukemia (CML). Tyrosine kinase inhibitors (TKIs) induce a potent antileukemic response mostly based on the inhibition of BCR-ABL, but they also increase the activity of Natural Killer (NK) and CD8+ T cells. After several years, patients may interrupt treatment due to sustained, deep molecular response. By unknown reasons, half of the patients relapse during treatment interruption, whereas others maintain a potent control of the residual leukemic cells for several years. In this study, several immunological parameters related to sustained antileukemic control were analyzed. According to our results, the features more related to poor antileukemic control were as follows: low levels of cytotoxic cells such as NK, (Natural Killer T) NKT and CD8±TCRγß+ T cells; low expression of activating receptors on the surface of NK and NKT cells; impaired synthesis of proinflammatory cytokines or proteases from NK cells; and HLA-E*0103 homozygosis and KIR haplotype BX. A Random Forest algorithm predicted 90% of the accuracy for the classification of CML patients in groups of relapse or non-relapse according to these parameters. Consequently, these features may be useful as biomarkers predictive of CML relapse in patients that are candidates to initiate treatment discontinuation.

Cytotoxic cell populations developed during treatment with tyrosine kinase inhibitors protect autologous CD4+ T cells from HIV-1 infection.

Tyrosine kinase inhibitors (TKIs) are successfully used in clinic to treat chronic myeloid leukemia (CML). Our group previously described that CD4+ T cells from patients with CML on treatment with TKIs such as dasatinib were resistant to HIV-1 infection ex vivo. The main mechanism for this antiviral activity was primarily based on the inhibition of SAMHD1 phosphorylation, which preserves the activity against HIV-1 of this innate immune factor. Approximately 50% CML patients who achieved a deep molecular response (DMR) may safely withdraw TKI treatment without molecular recurrence. Therefore, it has been speculated that TKIs may induce a potent antileukemic response that is maintained in most patients even one year after treatment interruption (TI). Subsequent to in vitro T-cell activation, we observed that SAMHD1 was phosphorylated in CD4+ T cells from CML patients who withdrew TKI treatment more than one year earlier, which indicated that these cells were now susceptible to HIV-1 infection. Importantly, these patients were seronegative for HIV-1 and seropositive for cytomegalovirus (CMV), but without CMV viremia. Although activated CD4+ T cells from CML patients on TI were apparently permissive to HIV-1 infection ex vivo, the frequency of proviral integration was reduced more than 12-fold on average when these cells were infected ex vivo in comparison with cells isolated from untreated, healthy donors. This reduced susceptibility to infection could be related to an enhanced NK-dependent cytotoxic activity, which was increased 8-fold on average when CD4+ T cells were infected ex vivo with HIV-1 in the presence of autologous NK cells. Enhanced cytotoxic activity was also observed in CD8 + T cells from these patients, which showed 8-fold increased expression of TCRγδ and more than 18-fold increased production of IFNγ upon activation with CMV peptides. In conclusion, treatment with TKIs induced a potent antileukemic response that may also have antiviral effects against HIV-1 and CMV, suggesting that transient use of TKIs in HIV-infected patients could develop a sustained antiviral response that would potentially interfere with HIV-1 reservoir dynamics.

Comparative evaluation of tests for detection of parvovirus B19 IgG and IgM.

The aim of this study was to evaluate enzyme immunoassays (EIA) (Euroimmun, Lübeck, Germany) and chemiluminiscent immunoassays (CLIA) (Diasorin, Saluggia, Italy) in their application to detect B19V-IgM and -IgG. For this purpose, one hundred and ninety samples were studied. Of them, 101 came from recent infection cases (B19V-specific IgM (86) and/or PCR (87), 42 from past infections, 18 from non-infected, and 29 from other viral recent infections (Epstein-Barr virus, measles, and rubella). Samples were characterized by capture (for IgM), or indirect (for IgG) EIA (Biotrin, Dublin, Ireland); indeterminate samples were classified by indirect immunofluorescence (IIF) (Biotrin). All the samples were used for testing IgM assays, and all but the cases from other viral infections were used for IgG tests. For IgM, CLIA, and EIA identified 76 and 62 of 86 IgM positives, respectively (sensitivity 88.4% and 72.1%). Considering B19V IgM negative samples, negative result was obtained in 95 and 92 of 104, being the specificity values of CLIA and EIA 91.3% and 88.5%, respectively. For IgG, CLIA and EIA identified correctly 114 and 115 of the 122 positive samples (sensitivity 93.4% and 94.3%, respectively), and 39 and 36 of 39 negative samples (specificity 100% and 92.3%). As conclusion, CLIA methods can be used in clinical laboratories as adequate alternatives to the well-established Biotrin EIAs.

Longitudinally extensive varicella-zoster virus myelitis in a patient with multiple sclerosis.

STUDY DESIGN: Case report. OBJECTIVE: To report this rare varicella-zoster virus (VZV) complication in a patient with multiple sclerosis. SUMMARY OF BACKGROUND DATA: Longitudinally extensive transverse myelitis is a spinal cord lesion that extends over 3 or more vertebral segments. A common feature in neuromyelitis optica, longitudinally extensive transverse myelitis can also occur in several other diseases. METHODS: A 15-year-old boy with relapsing-remitting multiple sclerosis, who has been treated with immunomodulators for 6 months, developed a subacute left brachiocrural hemiparesis with ipsilateral decreased sensation in the trunk and limbs. This was interpreted as a new relapse and was treated consequently. During the evolution, the patient developed a cutaneous rash in the left C8 metameres, followed by asymmetric tetraparesis. RESULTS: Magnetic resonance imaging demonstrated an extensive cervical-thoracic myelopathy. Cerebrospinal fluid analysis revealed 17 leukocytes per microliter (95% mononuclear), protein 41 mg/dL, and negative VZV-DNA by polymerase chain reaction, but elevated anti-VZV immunoglobulin G cerebrospinal fluid/serum index, with a normal albumin cerebrospinal fluid/serum index, all of which were consistent with intrathecal synthesis of anti-VZV antibody. We were able to rule out all other causes included in the differential diagnosis, namely, vascular disease, tumor, and autoimmune conditions, especially those associated with neuromyelitis optica spectrum disorders. CONCLUSION: Awareness of the potentially varied presentation of VZV myelitis can enable earlier recognition and specific treatment.

[Performance of the VIDAS automated immunoassay for the determination of Epstein-Barr virus serological status]. / Evaluación del sistema VIDAS para estudio de marcadores serológicos de infección por el virus Epstein Barr.

Enzyme linked fluorescent assays (VIDAS EBV VCA IgM, VIDAS EBV VCA/EA IgG and VIDAS EBV EBNA IgG (Biomérieux, France) were evaluated to determine markers for infection of Epstein Barr virus, as well as to establish antibody profiles, compared with immunofluorescence assays as reference. The assays evaluated showed good values for sensitivity, specificity and agreement, making them useful for their application in clinical laboratories.

Seroprevalence of antibodies to the influenza A (H1N1) virus among healthcare workers prior to the 2009 pandemic peak.

OBJECTIVE: Our aim was to study the proportion of healthcare workers with a positive serology for Influenza A(H1N1)2009 without having flu, in a Spanish hospital at the beginning of the pandemic. METHODS: A survey study carried out during August 2009 (before the peak of the pandemic in Spain) in the Hospital Costa del Sol, a second level hospital with almost 300 beds in the South of Spain. The participants were workers in the following hospital units: Emergencies, Medical Area (Internal Medicine, Chest Diseases), Surgical Area (General Surgery and Anaesthesia) of any professional category. A study was made of the proportion of healthcare workers in our hospital with positive serology for the new influenza A (H1N1)2009 virus, as determined by the haemagglutination inhibition technique (≥1/40). The subjects completed a health status questionnaire, and provided a blood sample for serology testing. RESULTS: A total of 239 workers participated, of whom 25.1% had positive serology. The hospital area in which most individuals had positive serology was the Emergency Department (36.6%), while the professional category in which most individuals with a positive serology worked was that of the orderlies (41.7%). CONCLUSION: Around 25% of healthcare workers in our hospital had positive serology before the peak of the pandemic, none of them had received vaccine for Influenza A (H1N1) 2009 or had been diagnosed of influenza previously.

Evaluation of four commercial systems for the diagnosis of Epstein-Barr virus primary infections.

To compare the performance of four diagnostic commercial systems for Epstein-Barr virus (EBV) serology (for IgM and IgG virus capsid antigen [VCA] and EBV nuclear antigen [EBNA] antibodies), a collection of 125 samples from clinically suspected infectious mononucleosis cases was studied. Indirect immunofluorescence (IIF) for VCA IgM and IgG antibodies and anticomplement immunofluorescence for EBNA antibodies (Meridian Bioscience Inc.) were used as reference methods. By these methods, the cases were classified EBV primary infection (presence of IgM to VCA or IgG to VCA in the absence of EBNA antibodies; n = 82), EBV past infection (presence of VCA IgG and EBNA antibodies in the absence of VCA IgM; n = 26), or no infection (negative for the three markers; n = 17). The following systems were tested: two chemiluminescent immunoassays (CLIAs; the Liason [CLIA-L; DiaSorin] and the Immulite 2000 [CLIA-I; Siemens]), immunofiltration (IF; All.Diag), and an enzyme-linked immunosorbent assay (ELISA; DiaSorin). In the IgM assays, sensitivities ranged from 67.1% (ELISA) to 92.2% (CLIA-L) and specificities ranged from 93.8% (CLIA-L) to 100% (IF). In the VCA IgG assays, sensitivities varied from 79.4% (IF) to 94.4% (CLIA-I) and specificities varied from 94.4% (IF and CLIA-L) to 100% (CLIA-I and ELISA). In EBNA assays, sensitivities ranged from 78.1% (IF) to 93.8% (CLIA-I) and specificities ranged from 32.3% (CLIA-L) to 91.4% (IF). In relation to EBV profiles, the corresponding figures for sensitivity (in detecting primary infection) for IF, CLIA-L, CLIA-I, and ELISA were 92.7%, 93.8%, 89%, and 89.6%, respectively, and those for specificity (to exclude primary recent infection) were 90.7%, 94.6%, 97.7%, and 95.2%, respectively. Although there were limitations in some individual markers, especially CLIA-L for EBNA IgG, the systems evaluated appear to be useful for diagnosis of EBV infection.

Immune response during adverse events after 17D-derived yellow fever vaccination in Europe.

BACKGROUND: In 1999-2000, reports of fatalities after vaccination with 17D-derived yellow fever vaccine (YEL) focused mainly on cases of YEL-associated adverse events (YEL-AEs) and YEL-associated viscerotropic disease (YEL-AVD). Here, we investigated 6 recent European cases to provide insight regarding immune response involvement and to identify potential risk factors. METHODS: Clinical, microbiological, molecular biological, and immunological assays were performed on serum from 6 patients with YEL-AEs, including 5 with YEL-AVD and 1 with YEL-associated neurotropic disease (YEL-AND). RESULTS: The levels of 3 liver enzymes associated with infection were clearly increased in all patients with YEL-AVD, but no elevations were observed in the patient with YEL-AND. In the patients with severe YEL-AVD, platelet counts were markedly reduced (< 100,000 cells/microL). The only patient with fatal YEL-AVD exhibited a cytokine profile comparable to that seen in YF: high levels of interleukin (IL)-6, IL-8, monocyte chemotactic protein (MCP)-1, monokine induced by interferon-gamma, and growth-related oncogene (GRO). The other patients with YEL-AVD exhibited similar but less severe cytokine profiles. The patient with YEL-AND exhibited a cytokine profile similar to that found in vaccinees without YEL-AEs: elevated levels of RANTES and low levels of GRO, MCP-1, transforming growth factor-beta1, and tumor necrosis factor-beta. CONCLUSIONS: On the basis of these results, we conclude that elevations in cytokine levels and reductions in platelet counts are suitable surrogate markers for patients likely to experience severe adverse reactions to YEL.

Detection of Chlamydophila pneumoniae IgG in paired serum samples: comparison of serological techniques in pneumonia cases.

Serological diagnosis of Chamydophila pneumoniae is usually undertaken by complement fixation test (CFT) or by microimmunofluorescence (MIF). A number of commercial methods for detecting C. pneumoniae-specific IgG have been developed. The aim of this study was to compare the performance characteristics of six methods for the diagnosis of pneumonia due to C. pneumoniae, including CFT (in house), MIF (Vircell, Spain), and four ELISAs (Medac, Germany; Savyon, Israel; Serion, Germany; and DRG, Germany). ELISA-Medac, ELISA-Savyon, ELISA-DRG and MIF use C. pneumoniae antigens while ELISA-Serion and CFT use Chlamydophila genus-specific antigen. Acute and convalescent samples from 85 pneumonia patients were studied. Using CFT, cases were initially classified as due to Chlamydophila (43 cases); to other agents (23 cases) (influenza A and B, Mycoplasma pneumoniae, respiratory syncytial virus, adenovirus and Legionella pneumophila); or as negative (19 cases). Cases were considered positive if they showed seroconversion, a significant rise in titer or high titer; and were finally classified as positive if they gave a positive result in at least three assays. Sensitivity values ranged from 87% to 97.8%; and specificity from 84.6% to 97.4%. In conclusion, the assays compared appear to be useful tools for the diagnosis of pneumonia due to Chlamydophila.

Comparison of commercial real-time PCR assays for quantification of Epstein-Barr virus DNA.

Clinical research suggests a role for viral load measurement in predicting and monitoring Epstein-Barr virus (EBV)-associated diseases. The aim of this study was to assess the performance of the recently commercially available quantitative assays for EBV based on real-time PCR: the RealArt EBV LC PCR kit and the LightCycler EBV quantification kit. A total of 87 samples were analyzed: 67 samples were obtained from transplant recipients and patients with EBV-associated diseases, 8 samples were obtained from the Quality Control for Molecular Diagnostics 2002 EBV Proficiency Program, and 12 negative qualitative nested PCR samples were used as negative controls. Inter- and intra-assay variabilities were determined by running replicates of two samples. All samples were run in a LightCycler instrument. The differences between positive and negative results were not considered statistically significant (P = 0.5355). There were no false-positive results using either method for nested PCR negative-control samples. The difference in viral load values using the two different methods was considered statistically significant (P < 0.01). The logarithmic linear correlation for both assays was low (r = 0.449) but significant (P < 0.01). The LightCycler EBV quantification kit showed a wider dispersal in results but produced substantially more-accurate melting temperature profile curves. The bias towards lower measurements was considerable in comparison with higher viral load. The differences in PCR efficiency and the presence of mutations could explain the disparity between the two methods. It was concluded that confidence intervals would be required to report the results rather than plain absolute values of viral load for patient monitoring.