Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Class of 2012 Abstract / Specific Aims: To compare and evaluate the therapies prescribed, the incidence of adverse drug events, and the time to clinical cure in transplant patients with a cytomegalovirus (CMV) infection at an academic medical center before and during the foscarnet nationwide shortage. Methods: This study was a retrospective chart review to compare CMV treatment prescribed and clinical outcomes in pediatric and adult transplant patients at an academic medical center. Transplant patients were evaluated over a 16 month time period between December 2009 and March 2011. The average dose (mg/kg) and prevalence ganciclovir, foscarnet, and cidofovir prescribed in transplant patients with CMV infection were evaluated. Additionally, the incidence of adverse drug events including acute renal dysfunction and myelosuppression were characterized. Main Results: There were 30 subjects diagnosed with CMV disease during the evalutaion period. Of all of the patients treated for CMV before the shortage, 79% received ganciclovir, 43% received foscarnet, and 21% received cidofovir. Following the shortage in September 2010, the usage of the antiviral agents changed to 100%, 25%, and 13% respectively. Overall the usage of ganciclovir increased while the usage of foscarnet decreased when there was a shortage of medication. Conclusions: The antiviral prescribing patterns changed significantly during the foscarnet shortage. The average dose and incidence of ganciclovir increased which likely contributed to serious adverse events. Due to the limited amount of patients treated for CMV and the short time frame, clinical cure could not be determined at this time. Drug shortages are a serious problem and significantly influence patient outcomes.

Cytomegalovirus (CMV) is an important antenatal infection that is prevalent in the developing world. The disabling and potentially fatal effects of CMV acquisition or reactivation during pregnancy on the developing foetus and or neonate are known but, factors predisposing pregnant women to CMV are not well studied. CMV has a wide host cell tropism that includes gut epithelial cells. CMV infection in the gut epithelial cells results in a leaky gut and potential gut microbial dysbiosis. In this study, we set out to determine the prevalence of CMV infection as well as factors associated with CMV reactivation in a cohort of pregnant Zimbabwean women. We also aimed to determine the role of CMV infection and CMV susceptibility host genetics on gut bacterial profiles. Seroprevalence of CMV was determined using the enzyme-linked immunosorbent assay. A high prevalence of previous exposure to CMV, as denoted by the presence of anti-CMV IgG antibodies in participants' sera, was observed. Anti-CMV IgM antibodies that denote active CMV infection were detected in the sera of 4.6% (n=35/524) study participants. Prevalence of CMV was also determined using real time PCR, CMV reactivation was higher (6.7%) when using PCR than when using immunological assays (4.6%). The presence of CMV DNA was significantly associated with HIV positivity (p=0.04). PCR is the gold standard for CMV diagnosis, thus, CMV DNA positivity was used to denote CMV infection status in this thesis. The second objective was to determine if the differential effect of CMV acquisition or reactivation among HIV infected participants was due to variability in plasma efavirenz containing antiretroviral therapy (ART) exposure. Efavirenz (EFV) plasma concentrations were determined using high performance liquid chromatography (HPLC). Single nucleotide polymorphisms (SNPs) in the CYP2B6 gene, which encodes the main EFV metabolizing enzyme were genotyped. Carriers of CYP2B6 poor metaboliser (PM) genotypes (c.516T/T and c.983T/C) had significantly higher mean plasma EFV concentration compared to carriers of CYP2B6 fast metabolizer genotypes (i.e., c.516G/G and c.983T/T). CYP2B6 PM genotype carriers were significantly less likely to be positive for CMV DNA when compared with fast metabolizer genotype carriers (pC (p=0.002), TLR7 rs179008A>C (pC (p=0.003). In contrast, presence of the IL6 rs10499563T>C polymorphism was inversely correlated with CMV infection (p=0.002). The reported genetic variants are reported to modulate proteins involved in immune responses against viral infections, thus, their association with susceptibility to CMV infection. Such findings may assist in the designing of a muchneeded candidate CMV vaccine. Lastly, we set out to determine the possible role of CMV infection in shaping gut microbiota profiles. We report on a significant difference (p=0.001) in the beta diversity of gut bacterial profiles between HIV- and age-matched CMV-infected (cases) and CMVuninfected (controls) participants. Using linear discriminant analysis (LDA) effect size (LefSe), significant differences in the relative abundance of specific bacterial taxa were observed between cases and controls (p2). Significantly lower abundance of Lactobacillus reuteri and Roseburia, genera associated with lower microbial translocation was observed in cases than controls. Lower relative abundance of Lactobacillus and Roseburia, is consistent with microbial translocation and heightened inflammation, respectively, hence higher likelihood of microbial translocation and inflammation occurring in cases than controls. Furthermore, Prevotella copri, a species that has been association with cytokine release and chronic inflammation was significantly more abundant in cases than controls. CMV is a known chronic inflammatory condition, and this study provides further confirmation through the higher relative abundance of P.copri in cases than controls. Biomarker identification has proven to be a successful means of translating molecular data into clinical practice, such as vaccine development in the case of CMV infection. Overall, this study reports the possible interaction of various host factors in facilitating CMV acquisition or reactivation during pregnancy. In the setting of HIV-CMV coinfection, our findings emphasise on the need for genotype guided drug dosage to achieve therapeutic EFV so as to maintain the balance between host and coinfecting microbes in HIV management. Comprehensive genotype guided drug dosage, if taken as a once-off test should be affordable especially in resource-limited settings. This is particularly important in pregnant women who are at a risk of vertically transmitting infection to the immunologically immature foetus and or neonate. Data from this study may assist in curbing the host associated challenges in designing an effective CMV vaccine. Moreover, the biomarkers reported may assist in diagnosis and management of potential CMV acquisition or reactivation during pregnancy. However, bigger prospective, functional studies would be needed to confirm the exact roles of the biomarkers identified in this study in the diagnosis, prognosis and therapeutics of CMV infection.

No description available.

No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 6 uppsatser.

Thesis (Ph. D.)--University of Virginia, 2008. / Includes bibliographical references. Also available online through Digital Dissertations.

AIDS-related human cytomegalovirus (HCMV) retinitis remains the leading cause of blindness among untreated HIV/AIDS patients worldwide. Understanding the pathogenesis of this disease is essential for developing new, safe, and effective treatments for its prevention or management, yet much remains unknown about the virologic and immunologic mechanisms contributing to its pathology. To study such mechanisms, we use a well-established, reproducible, and clinically relevant animal model with retrovirus-induced murine acquired immunodeficiency syndrome (MAIDS) that mimics in mice the symptoms and progression of AIDS in humans. Over 8 to 12 weeks, MAIDS mice become susceptible to experimental murine cytomegalovirus (MCMV) retinitis. We have found in this model that MCMV infection significantly stimulates ocular suppressor of cytokine signaling (SOCS)1 and SOCS3, host proteins which dampen immune-related signaling by cytokines, including antiviral interferons. Herein we investigated virologic and/or immunologic mechanisms involved in this stimulation and how virally-modulated SOCS1 and/or SOCS3 proteins may contribute to MCMV infection or experimental MAIDS-related MCMV retinitis. Through pursuit of two specific aims, we tested the central hypothesis that MCMV stimulates and employs SOCS1 and/or SOCS3 to induce the onset and development of MCMV retinal disease. MCMV-related SOCS1 and SOCS3 stimulation in vivo occurred with intraocular infection, was dependent on method and stage of immune suppression and severity of ocular pathology, was associated with stimulation of SOCS-inducing cytokines, and SOCS1 and SOCS3 were differentially sensitive to antiviral treatment. In vitro studies further demonstrated that SOCS1 and SOCS3 stimulation during MCMV infection occurred with expected immediate early kinetics, required viral gene expression in cell-type-dependent and virus origin-dependent patterns of expression, and displayed differential sensitivity to antiviral treatment. These data suggest that SOCS1 and SOCS3 are stimulated by divergent virologic, immunologic, and/or pathologic mechanisms during MCMV infection, and that they contribute to the pathogenesis of retinal disease, revealing new insights into the pathophysiology of AIDS-related HCMV retinitis.

Human cytomegalovirus (HCMV) coexists indefinitely in infected individuals through a poorly characterized latent infection in hematopoietic cells. We previously demonstrated a requirement for UL138 in promoting a latent infection in CD34+ hematopoietic progenitor cells (HPCs). UL138 is encoded on three co-terminal transcripts of, 1.7-, 2.7-, and 3.6-kilobases. Interestingly, the UL138 protein product (pUL138) is necessary but insufficient for HCMV latency. The mechanisms by which pUL138 contributes to the latent infection are unknown, however other viral determinants are required for the latent infection. We identified 3 novel proteins pUL133, pUL135, and pUL136 encoded on the UL138 transcripts. Similar to pUL138, pUL133, pUL135, and pUL136 are Golgi localized type I transmembrane proteins expressed with early kinetics during productive infection. We have named these UL138 related proteins, CLAMPs for HCMV Latency Associated Membrane Proteins. Through a systematic immunoprecipitation analysis, we identified interactions between the CLAMPs and characterized an interaction between pUL133 and pUL138. Further, we mapped the interacting region to a specific domain in the C-terminal, cytosolic tail of pUL138. Additionally, we show that each of the CLAMPs has the ability to self-associate. The localization of the CLAMPs to the Golgi suggests that these proteins likely promote HCMV latency through a novel mechanism involving Golgi functions. Additionally, through a Y2H screen of a human bone marrow cDNA library, we identified an interaction between pUL138 and the heat shock protein 40 (Hsp40) variant MRJ. We confirmed this interaction in mammalian cells and mapped the pUL138 region responsible for this interaction to a domain in the cytoplasmic tail of pUL138. We also demonstrated additional MRJ interactions with pUL133 and pUL136. Importantly, pUL138 specifically interacts with Hsp40 variants during productive infection. Preliminary data suggest that HCMV infection up regulates MRJ mRNA expression and recombinant viruses lacking pUL138 show a disproportionate up regulation of MRJ. pUL138 is the first HCMV protein demonstrated to promote a latent infection. While the mechanisms by which pUL138 contributes to latency remain unknown, the interaction with other CLAMPs and with MRJ, suggest that pUL138 may cooperate with other CLAMPs to modulate the cellular stress response at the Golgi to promote HCMV latency.