Lowered Immune Cell Function in Liver Recipients Recovered From Posttransplant Lymphoproliferative Disease Who Developed Graft Tolerance

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Chronic benign neutropenia among Chinese children

Objective. To delineate the clinical behaviour of chronic benign neutropenia in Chinese children in Hong Kong. Design. Retrospective study. Setting. University teaching hospital, Hong Kong. Patients. All infants and children with absolute neutrophil count of 1.5 × 109 /L or lower for more than 3 months. Main outcome measures. Development of significant infection, and achievement of remission. Results. Twenty-four children with chronic benign neutropenia were identified between 1992 and 2001. Their median age of diagnosis was 9 months. The mean (standard deviation) initial absolute neutrophil count was 0.28 × 109 /L (0.24 × 109 /L). Twenty-three patients presented with infection. Of the 19 patients tested, four (21%) were positive for anti-neutrophil antibodies. Bone marrow examination was performed in 17 patients: nine had normal results, but six showed evidence of peripheral consumption, one showed late maturation arrest at band stage, and one showed phagocytosis of myeloid cells by histiocytes. The overall hospitalised infection rate was 51.6 episodes per 1000 patient-months. Ten percent of cases were considered 'significant' infections and required hospital admission with either surgical intervention or intravenous therapy (antibiotics or fluid replacement). In the first year of diagnosis, more than 80% of patients had their lowest absolute neutrophil count (mean, 0.16 × 109 /L; standard deviation, 0.11 × 109 /L). Granulocyte-colony stimulating factor was used to treat three patients and induced transient elevation of absolute neutrophil count in all three. The projected remission rate was 55.4% at 3 years. Even for those with persistent disease, there was significant recovery in absolute neutrophil count to a mean of 0.5 × 109 /L (P<0.01). Conclusions. Patients with chronic benign neutropenia experienced a relatively benign clinical course regardless of their remission status. Only a small proportion of patients developed significant infections. A multi-centre prospective study may help identify predictive factors of remission.published_or_final_versio

A Modified Protocol with Improved Detection Rate for Mis-Matched Donor HLA from Low Quantities of DNA in Urine Samples from Kidney Graft Recipients

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Identification of novel porcine and bovine parvoviruses closely related to human parvovirus 4

Human parvovirus 4 (PARV4), a recently discovered parvovirus found exclusively in human plasma and liver tissue, was considered phylogenetically distinct from other parvoviruses. Here, we report the discovery of two novel parvoviruses closely related to PARV4, porcine hokovirus (PHoV) and bovine hokovirus (BHoV), from porcine and bovine samples in Hong Kong. Their nearly full-length sequences were also analysed. PARV4-like viruses were detected by PCR among 44.4% (148/333) of porcine samples (including lymph nodes, liver, serum, nasopharyngeal and faecal samples), 13% (4/32) of bovine spleen samples and 2% (7/362) of human serum samples that were sent for human immunodeficiency virus and hepatitis C virus antibody tests. Three distinct parvoviruses were identified, including two novel parvoviruses, PHoV and BHoV, from porcine and bovine samples and PARV4 from humans, respectively. Analysis of genome pequences from seven PHoV strains, from three BHoV strains and from one PARV4 strain showed that the two animal parvoviruses were most similar to PARV4 with 61.5-63% nt identities and, together with PARV4 (HHoV), formed a distinct cluster within the family Parvoviridae. The three parvoviruses also differed from other parvoviruses by their relatively large predicted VP1 protein and the presence of a small unique conserved putative protein. Based on these results, we propose a separate genus, Hokovirus, to describe these three parvoviruses. The co-detection of porcine reproductive and respiratory syndrome virus, the agent associated with the recent 'high fever' disease outbreaks in pigs in China, from our porcine samples warrants further investigation. © 2008 SGM.published_or_final_versio

Assessment of SARS-CoV-2 Immunity in Convalescent Children and Adolescents

Persistence of protective immunity for SARS-CoV-2 is important against reinfection. Knowledge on SARS-CoV-2 immunity in pediatric patients is currently lacking. We opted to assess the SARS-CoV-2 adaptive immunity in recovered children and adolescents, addressing the pediatrics specific immunity towards COVID-19. Two independent assays were performed to investigate humoral and cellular immunological memory in pediatric convalescent COVID-19 patients. Specifically, RBD IgG, CD4+, and CD8+ T cell responses were identified and quantified in recovered children and adolescents. SARS-CoV-2-specific RBD IgG detected in recovered patients had a half-life of 121.6 days and estimated duration of 7.9 months compared with baseline levels in controls. The specific T cell response was shown to be independent of days after diagnosis. Both CD4+ and CD8+ T cells showed robust responses not only to spike (S) peptides (a main target of vaccine platforms) but were also similarly activated when stimulated by membrane (M) and nuclear (N) peptides. Importantly, we found the differences in the adaptive responses were correlated with the age of the recovered patients. The CD4+ T cell response to SARS-CoV-2 S peptide in children aged <12 years correlated with higher SARS-CoV-2 RBD IgG levels, suggesting the importance of a T cell-dependent humoral response in younger children under 12 years. Both cellular and humoral immunity against SARS-CoV-2 infections can be induced in pediatric patients. Our important findings provide fundamental knowledge on the immune memory responses to SARS-CoV-2 in recovered pediatric patients

Preventing the next 'SARS' - European healthcare workers' attitudes towards monitoring their health for the surveillance of newly emerging infections: qualitative study

<p>Abstract</p> <p>Background</p> <p>Hospitals are often the epicentres of newly circulating infections. Healthcare workers (HCWs) are at high risk of acquiring infectious diseases and may be among the first to contract emerging infections. This study aims to explore European HCWs' perceptions and attitudes towards monitoring their absence and symptom reports for surveillance of newly circulating infections.</p> <p>Methods</p> <p>A qualitative study with thematic analysis was conducted using focus group methodology. Forty-nine hospital-based HCWs from 12 hospitals were recruited to six focus groups; two each in England and Hungary and one each in Germany and Greece.</p> <p>Results</p> <p>HCWs perceived risk factors for occupationally acquired infectious diseases to be 1.) exposure to patients with undiagnosed infections 2.) break-down in infection control procedures 3.) immuno-naïvety and 4.) symptomatic colleagues. They were concerned that a lack of monitoring and guidelines for infectious HCWs posed a risk to staff and patients and felt employers failed to take a positive interest in their health. Staffing demands and loss of income were noted as pressures to attend work when unwell. In the UK, Hungary and Greece participants felt monitoring staff absence and the routine disclosure of symptoms could be appropriate provided the effectiveness and efficiency of such a system were demonstrable. In Germany, legislation, privacy and confidentiality were identified as barriers.</p> <p>All HCWs highlighted the need for knowledge and structural improvements for timelier recognition of emerging infections. These included increased suspicion and awareness among staff and standardised, homogenous absence reporting systems.</p> <p>Conclusions</p> <p>Monitoring absence and infectious disease symptom reports among HCWs may be a feasible means of surveillance for emerging infections in some settings. A pre-requisite will be tackling the drivers for symptomatic HCWs to attend work.</p

ADAMTS13 mutational analysis in Chinese patients with chronic relapsing thrombotic thrombocytopenic purpura

Mutational analysis of ADAMTS13 gene was performed on three Chinese children with chronic relapsing thrombotic thrombocytopenic purpura, who all showed severe deficiency (<5% activity) of von Willebrand factor-cleaving protease (vWF-CP) and lack of inhibitors. In two patients, three new mutations, namely G194V, R349C and G1181R, were identified along with a fourth mutation A596V recently described in a French patient. No significant ADAMTS13 gene defect was detected in one patient, in whom the presence of low titer or non-neutralizing antibodies to vWF-CP was not excluded. The prevalence of G194V and G1181R mutations was 1.5% and 5.8% among normal Chinese subjects. They may constitute genetic susceptibility factors for thrombosis in the population.link_to_OA_fulltex