Claudia Honsig

Human cytomegalovirus (HCMV) replication is limited by HCMV-specific natural killer (NK) cell response. Distinct genetic polymorphisms, which are potentially involved in antiviral NK cell response, have been described. Here, the association between polymorphisms at IgG1 genetic marker 3/17, FcγRIIIα/CD16a 158V/F, NKG2Cwt/del, CD226/rs727088, and rs763361, respectively, and HCMV viremia and disease were investigated in 98 lung transplant recipients (LTRs), within 9 months after stop of posttransplant HCMV prophylaxis. From all variants, only the NKG2Cwt/wt genotype was significantly associated with freedom from HCMV viremia (P = .0002) and disease (P = .02), compared with the NKG2Cwt/del genotype. Thus, LTRs expressing the homozygous NKG2C wild type seem to have a selective advantage in HCMV defense.

Invasive infections caused by filamentous fungi constitute a leading cause of morbidity and mortality in immunocompromised patients. Rapid and reliable identification of filamentous fungi is essential for the early initiation of appropriate treatment. In the present study, 230 filamentous fungi isolates identified by conventional methods were investigated using MALDI-TOF MS (Bruker Daltonics, Bremen, Germany) in combination with the Filamentous Fungi Library 3.0 provided by the manufacturer. Three different sample preparation methods were applied as recommended by the manufacturer and identification rates were compared using the criteria provided by the manufacturer. Application of the more time-consuming sample preparation methods clearly improved identification at the species level. Thus, the identification rate increased from 48.9% using the simplest method to 76.1% with the most laborious procedure. Misidentifications did not occur. Furthermore, the reliability of an in-house threshold for species identification was investigated. The reduced threshold increased the rate of isolates correctly identified at the species level by up to 86.4%. As no misidentification was made at the genus level and only one misidentification of minor significance occurred at the species level, this threshold could be validated for routine use in our laboratory. In conclusion, regarding the high identification rates achieved, this commercial platform proved suitable for implementation in routine diagnosis.

Infection with human cytomegalovirus (HCMV) is associated with substantial morbidity in immunosuppressed patients and after congenital infections. Therefore, development of a vaccine against HCMV is a main public health priority. Revealing the complex interaction between HCMV and host responses, is of utmost importance for understanding viral pathogenesis and for vaccine design. The present data contribute to the understanding of HCMV-specific host immune responses and reveal specifically the interaction between HLA-E and the virus-encoded UL40 peptide, which further leads to a potent NK cell response. We demonstrate that this interaction is a key factor for reduction of virus replication in immunosuppressed patients. We further show that distinct naturally occurring HCMV-UL40 variants reduce the activation of a specific subpopulation of host NK cells and thereby are associated with high-level viremia in the patients. These findings will allow the characterization of patients at risk for severe HCMV infection and contribute to strategies for HCMV vaccine development.

The aim of this retrospective study was the identification of clinically useful viral determinants for the prediction of hepatitis B surface antigen (HBsAg) seroclearance and sustained virological response in hepatitis B virus/human immunodeficiency virus (HBV-/HIV)-coinfected patients receiving HBV-active combined antiretroviral therapy (cART). Quantification of HBsAg, HBeAg and HBV DNA before and after initiation of HBV-active cART in a cohort of 59 HIV-/HBV-coinfected patients was performed. Calculations of receiver operating characteristics (ROC) and Kaplan-Meier analysis were used for the identification of predictors of HBsAg seroclearance for HBeAg-positive [HBeAg(+); n = 36] and HBeAg-negative [HBeAg(-);n = 23] patients. HBeAg(+) patients with an HBsAg on-treatment decline ≥ 1 log IU/mL per year achieved higher HBsAg loss rates (P = 0.0294), whereas the quantification of HBeAg had no predictive value for HBsAg seroclearance. Among HBeAg(-) patients, a pretreatment baseline cut-off level of HBsAg ≤ 100 IU/mL was highly predictive for HBsAg seroclearance. No significant influence of the HBV genotype on HBsAg seroclearance was observed among the entire cohort. Quantitative determination of HBsAg provides a clinically useful viral parameter for the prediction of HBsAg seroclearance both in HBeAg(+) and HBeAg(-) HIV-/HBV-coinfected patients receiving HBV-active cART.