The assessment of microbial infection in children with autism spectrum disorders and genetic folate cycle deficiency.

BACKGROUND: The results of disparate clinical studies indicate abnormally frequent cases of certain microorganisms in children with autism spectrum disorders (ASD). However, these data require clarification and systematization. The study aims to study the structure of the microbial profile in children with ASD and genetic folate cycle deficiency (GFCD) and consider differences in diagnostic approaches for identifying microorganisms of different types. METHODS: The study analyzed medical data from 240 children (187 boys and 63 girls) with GFCD aged 2 to 9 years. The children had clinical manifestations of ASD (the study group, SG). The control group (CG) included 53 clinically healthy children (37 boys and 16 girls) of the same age but without GFCD. Both groups of children were tested on active herpetic infections (HSV-1/2, VZV, EBV, CMV, HHV-6, HHV-7, HHV-8), ТТV, Streptococcus pyogenes, Candida albicans, Borrelia burgdorferi, Mycoplasma pneumoniae, Chlamydia pneumoniae, Yersinia enterocolitica, Toxoplasma gondii, congenital CMV neuroinfection and postnatal HSV-1/2 encephalitis. The testing used diagnostic methods specified in PubMed-indexed studies. RESULTS: In the SG, TTV was found in 196 children (82%), HHV-7 - in 172 (72%), HHV-6 - in 162 (68%), EBV - in 153 (64%), Streptococcus pyogenes - in 127 (53%), Candida albicans - in 116 (48%), Borrelia - in 107 (45%), Mycoplasma pneumoniae - in 94 (39%), Chlamydia pneumoniae - in 85 (35%), Yersinia entеrocolitica - in 71 (30%), Toxoplasma gondii - in 54 (23%), congenital CMV neuroinfection - in 26 (11%), and postnatal HSV-1/2 encephalitis - in 11 children (5% of cases) (p < p0.05; Z < Z0.05). In the SG, there was a higher microbial load in older children (p < p0.05; Z < Z0.05). No gender differences were found. CONCLUSIONS: The study described and characterized a specific abnormal microbial spectrum with a predominance of viral opportunistic agents in children with ASD associated with GFCD.

Clinical, Viral and Genetic Characteristics of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) in Shanghai, China.

DRESS is one of the most severe drug reactions. The aim of this retrospective study was to summarize the clinical presentation, genetic predisposition and prognostic factors of DRESS. A total of 52 patients with DRESS, who were inpatients at a medical referral centre in Shanghai, China, from January 2011 to December 2016, were analysed retrospectively. All the patients had skin eruption, 83% had liver involvement, and ≤10% had other organ involvement. Mean cost of hospitalization was US$5,511±3,050. The 3 most common causative agents were allopurinol (18/52; 35%), salazosulphapyridine (11/52; 21%) and carbamazepine (5/52; 10%). HLA-B*5801 and HLA-B*1302 were associated with allopurinol-induced DRESS. HLA-B*1301 was related to salazosulphapyridine-induced DRESS. The mortality rate was 6% (3/52). Epstein-Barr virus DNA was found in 10 patients (19%) and indicated a poor prognosis. Human herpes virus 6 DNA was detected in 17 patients (33%) and was associated with autoimmune sequelae. Due to its high medical cost and sometimes poor prognosis, prevention of DRESS should be a high priority.

Multicenter external quality assessment of molecular methods for detection of human herpesvirus 6.

The purpose of this study was to evaluate the performance of laboratories for the detection and quantification of human herpesvirus 6 (HHV-6) by an external quality assessment (EQA) evaluation. The HHV-6 EQA panel consisted of eight samples containing various concentrations of HHV-6 type A (strain GS) or type B (strain Z29), two samples containing other herpesviruses (i.e., human cytomegalovirus [HCMV] and Epstein-Barr virus [EBV]), and two HHV-6-negative samples. Panel samples were prepared in human plasma, heat inactivated, and lyophilized. Panel distribution, data management, and analysis were coordinated by Quality Control for Molecular Diagnostics (QCMD), Glasgow, United Kingdom. Fifty-one laboratories participated and submitted 57 data sets. Eleven (19.3%) data sets were generated using conventional in-house assays, 11 (19.3%) data sets using commercial real-time PCR assays, and 35 (61.4%) data sets using in-house real-time PCR assays. The presence of HHV-6 DNA at viral loads exceeding 6,000 copies/ml was detected by all participants, and over 80% of the participants still reported correct qualitative results for the sample containing just over 200 copies/ml. The false-positivity rate was 1.8% for both the negative samples and the samples containing HCMV or EBV DNA. The majority (23/33; 69.7%) of quantitative data sets were generated using in-house real-time PCR assays. The standard deviations of the geometric means of the samples ranged from 0.5 to 0.7 log(10). The results of this first international EQA demonstrate encouraging analytical sensitivity for the detection of HHV-6-DNA in human plasma, although we observed extensive interlaboratory variation of quantitative HHV-6 DNA results. Standardization needs to be improved to allow further elucidation of the clinical significance of HHV-6 loads.

Assessment of human herpesvirus-6 infection in mesenchymal stromal cells ex vivo expanded for clinical use.

Infection or reactivation of human herpesvirus (HHV)-6 represents a potentially serious complication (often involving the central nervous system) in patients receiving either solid organ or hematopoietic stem cell transplantation. The objective of this study was to assess the risk of HHV-6 infection/reactivation in mesenchymal stromal cells (MSCs). MSCs are multipotent cells displaying immunomodulatory properties that have been already successfully used in the clinical setting to enhance hematopoietic stem cell engraftment and to treat steroid-refractory acute graft-versus-host disease. We analyzed 20 samples of ex vivo expanded MSCs, at different passages of culture, isolated both from bone marrow and from umbilical cord blood. Through Western blotting and immunocytochemistry techniques, we investigated the presence of the HHV-6 receptor (CD46) on cell surface, whereas the presence of HHV-6 DNA was evaluated by nested polymerase chain reaction assay. All of the MSC samples tested were positive for the virus receptor (CD46), suggesting their potential susceptibility to HHV-6. However, none of the MSC samples derived from cultures, performed in the perspective of clinical use, was found to harbor HHV-6. This preliminary observation on a consistent number of MSC samples, some of them tested at late in vitro passages, indicates a good safety profile of the product in terms of HHV-6 contamination. Nevertheless, it remains important to set up in vitro experimental models to study MSCs' susceptibility to HHV-6 (and HHV-7) infection, to verify their capacity to integrate the virus into cellular DNA, and to investigate which experimental conditions are able to induce virus reactivation.

An assessment of herpesvirus co-infections in patients with CMV disease: correlation with clinical and virologic outcomes.

The effect of herpesvirus co-infections (HHV-6, HHV-7) on cytomegalovirus (CMV) disease and its response to therapy is unknown. We prospectively analyzed herpesvirus co-infections in transplant recipients with CMV disease. All patients received 3 weeks of antiviral therapy. Samples were collected at baseline (day 0) and then day 3, 7, 14 and 21 poststart of therapy. Viral load testing for CMV, HHV-6 and HHV-7 was done using quantitative PCR assays in 302 patients of whom 256 had documented symptomatic CMV viremia. In this subset, day 0 HHV-6 co-infection was present in 23/253 (9.1%) and HHV-7 in 17/253 (6.7%). Including those positive at any time point raised the prevalence to 79/256 (30.9%) for HHV-6 and 75/256 (29.3%) for HHV-7. Viral co-infection did not influence the response of CMV disease to antiviral therapy. Baseline CMV viral loads, time to eradication and risk of recurrence were similar in patients with and without HHV-6 or HHV-7 co-infection. Ganciclovir and valganciclovir had no clear effect on HHV-6 and HHV-7 viremia. In conclusion, herpesvirus co-infections are common in patients with CMV disease but with standard antiviral therapy, no clear clinical effects are discernable. Routine monitoring for viral co-infection in patients with CMV disease is not indicated.