Current practice in diagnosis and treatment of acute graft-versus-host disease: results from a survey among German-Austrian-Swiss hematopoietic stem cell transplant centers.

To assess current clinical practice in diagnosis and treatment of acute graft-versus-host disease (aGVHD), we performed a survey among German, Austrian, and Swiss allogeneic hematopoietic stem cell transplantation (allo-HSCT) centers. Thirty-four of 72 contacted centers (47%) completed both the diagnostic and therapeutic sections of the survey, representing 65% of allo-HSCT activity within the participating countries in 2011. Three pediatric centers answered as requested only the diagnostic part of the survey. In the presence of diarrhea and decreased oral intake after engraftment, only 4 centers (12%) do not perform any endoscopy before the start of immunosuppressive treatment. In case of a skin rash with the differential diagnosis of drug reaction, only 12 centers (35%) perform a skin biopsy up front, whereas 19 do so after failure of systemic steroids. In the presence of rapidly increasing cholestasis occurring without any other signs of aGVHD, 11 centers (32%) perform a liver biopsy up front and 14 only after failure of steroid treatment, whereas 9 centers do not perform a liver biopsy at all. Twenty centers (59%) use a percutaneous approach, 12 a transvenous approach, and 1 mini-laparoscopy for liver biopsies. First-line treatment of cutaneous aGVHD stage 1 consists of topical treatment alone in 17 of 31 responding centers (61%), whereas isolated cutaneous aGVHD stage III is treated with systemic steroids (prednisolone below 0.5 mg/kg/day n = 2, 0.5 to 1.0 mg/kg/day n = 10, above 1.0 to 2.5 mg/kg/day n = 19) without or with topical agents (steroids n = 10; calcineurin inhibitors n = 3). In gastrointestinal manifestations of aGVHD, 9 centers (29%) add topical to systemic steroids, and 3 consider topical steroids as the only treatment for mild gastrointestinal and cutaneous aGVHD. The choice of agent for second-line treatment as well as the sequence of administration are extremely heterogeneous, most likely due to a lack of convincing data published. Most frequently used are mycophenolate mofetil (n = 14) and extracorporeal photopheresis (n = 10). Our survey also demonstrates that clinicians chose salvage therapies for steroid-refractory aGVHD based on their centers' own clinical experience.

(Oligo)mannose functionalized hydroxyethyl starch nanocapsules: en route to drug delivery systems with targeting properties.

Hydroxyethyl starch nanocapsules (NCs) are potentially interesting hydrophilic drug delivery carriers, since they do not show non-specific interactions with the living cells. Only the presence of a targeting agent on their surface allows them to target specifically the desired site of action. In this paper, we report the synthesis and cell uptake of crosslinked hydroxyethyl starch (HES) NCs decorated with (oligo)mannose, which is an effective targeting agent for macrophage and dendritic cells. The crosslinked HES NCs were prepared via the interfacial polyaddition of HES with 2,4-toluene diisocyanate (TDI) in inverse (water-in-oil) miniemulsion and then functionalized with (oligo)mannose following two different strategies. To compare the activity and availability of a targeting agent, different types of mannose molecules such as α-d-mannopyranosylphenyl isothiocyanate, 3-O-(α-d-mannopyranosyl)-d-mannose and α3,α6-mannotriose were used for the functionalization of NCs. The availability of the mannose was unambiguously assessed by interaction with a fluorescent lectin. Moreover, the accessibility of the pilot molecule was improved by the presence of a PEG linker at the surface of the NCs. To simulate in vivo conditions, where proteins interact with nanoparticles with a possible hindrance of the accessibility to the targeting agent, the mannosylated NCs were first incubated with human serum before interaction with the fluorescent lectin. Enhancement of uptake into dendritic cells demonstrates the targeting ability in in vitro studies.

Recovery of varicella-zoster virus-specific T cell immunity after T cell-depleted allogeneic transplantation requires symptomatic virus reactivation.

Reactivated varicella-zoster virus (VZV) infection causes herpes zoster and commonly occurs after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Because VZV-specific T cell immunity is essential to prevent virus reactivation, we developed an interferon-gamma enzyme-linked immunosorbent spot (ELISPOT) assay for the sensitive detection of VZV-reactive T cells at the single-cell level ex vivo. We used this assay to monitor the frequency of VZV-reactive T cells in 17 seropositive patients during the first year after T cell-depleted allo-HSCT. The patients did not receive anti-herpesvirus prophylaxis after stem cell engraftment. Independent of the magnitude of transferred donor immunity, VZV-reactive T cell numbers decreased to low levels (median, 2/mL; range, 0 to 35/mL) in peripheral blood early after transplantation. Only patients with subsequent zoster (n = 5) exhibited a dramatic boost in VZV-reactive T cells (median, 366/mL; range, 158 to 756/mL), which was induced by the reactivation event. The postzoster VZV-reactive T cell levels were similar to those seen in healthy virus carriers. In contrast, antiviral T cell levels remained low in patients without VZV disease. Our results demonstrate that VZV-specific T cell immunity recovered efficiently during zoster in T cell-depleted allo-HSCT recipients. It did not reconstitute spontaneously in nonzoster patients, even in the absence of antiviral prophylaxis. Prospective studies should investigate whether VZV vaccination can substitute for natural resensitization by virus disease.