Faculty Bibliography

The feasibility of fidaxomicin versus vancomycin and metronidazole (conventional therapy) was assessed in 59 transplant recipients with 61 episodes of Clostridium difficile-associated diarrhea (CDAD). Overall clinical cure was achieved in 86% of episodes, and in 7% of episodes, infection recurred. Fidaxomicin was well tolerated. Clinical cures were not significantly different compared with conventional therapy (67% versus 89%, respectively; P = 0.06). Univariate analysis of predictors for lack of clinical cure included continued use of broad-spectrum systemic antibiotics (P = 0.026) and prior diagnosis of CDAD (95% confidence interval, 1.113 to 19.569; odds ratio, 4.667; P = 0.041). New-onset vancomycin-resistant Enterococcus (VRE) colonization was not noted after fidaxomicin therapy alone. However, this occurred in 10 of 28 patients (36%) following conventional therapy, and 2 of 3 patients with subsequent bacteremia died.

Response to systemic antifungal therapy alone remains disproportionately less satisfactory in immunosuppressed transplant and oncology patients. As insight in fungal immunopathogenesis forges ahead, interventions for boosting immune functions along with antimicrobial drugs has shown promise in preclinical experiments. The clinical experience with immunotherapy for invasive mold disease is limited. Most studies have involved small numbers of patients at a single institution or data collected retrospectively. An overview of various facts of immune modulatory drug intervention is presented, including major considerations in antifungal immunotherapy in immunosuppressed patients. Patients in whom immunotherapy is being considered must be critically evaluated to identify the underlying immune defects, including treatment-induced immunosuppression. Antifungal immunotherapy is appealing; however, before routine clinical use is recommended, well-designed prospective comparative clinical trials are urgently needed.

BACKGROUND: Cancer patients can exhibit negligible responses to prophylactic vaccinations, including influenza vaccination. To help address this issue, we developed in vitro and in vivo models of dendritic cell (DC) immunotherapy for the prevention of influenza virus infection. METHODS: Human cord blood (CB)-derived or mouse splenocyte-derived DCs were loaded with purified recombinant hemagglutinin (rHA). T-cell responses to HA-loaded CB-derived DCs were determined by ELISpot. Protective efficacy was determined by vaccination of BALB/c mice with a single injection of 10(6) autologous DCs. DC migration to peripheral lymphoid organs was verified by carboxyfluorescein succinimidyl ester staining, and HA-specific antibody titers were determined by enzyme-linked immunosorbent assay. Mice were then challenged intranasally with BALB/c-adapted A/New Caledonia influenza virus derived from four consecutive lung pool passages. Antigen-presenting cell (APC) dysfunction was modeled using the MAFIA transgenic system, in which the Csf1r promoter conditionally drives AP20178-inducible Fas. RESULTS: CB-derived human DCs were able to generate de novo T-cell responses against rHA, as determined by a system of rigorous controls. Mice vaccinated intraperitoneally developed HA titers detectable at serum dilutions of >1:1000. HA seroconverters survived virus challenge, whereas unvaccinated controls and vaccinated nonseroconverters lost weight and died. Furthermore, use of a model of APC-specific immunosuppression revealed that DC vaccination could generate HA-specific antibody titers under conditions in which protein vaccination could not. CONCLUSIONS: The model demonstrates that DC immunotherapy for the prevention of influenza is feasible, and studies are underway to determine whether populations of immunosuppressed individuals might ultimately benefit from the procedure.

Background/Aims: Adding granulocyte macrophage colony-stimulating factor (GM-CSF) may improve the response to antifungal therapy in immunosuppressed patients with invasive fungal disease (IFD). Methods: We retrospectively assessed 66 patients in whom GM-CSF was given during antifungal therapy. Results: Severe neutropenia (77%) and refractory/relapsed cancer (65%) were common in the group. Prior to GM-CSF therapy, 15% of patients received high-dose corticosteroids for a median of 30 +/- 16 days [median cumulative dose (c.d.) 1,184 +/- 1,019 mg], and 9 received steroids during GM-CSF therapy for a median of 16 +/- 12 days (median c.d. 230 +/- 1,314 mg). Mild toxic effects were noted in 9% of patients; there were no cases of cardiopulmonary toxicity. All-cause deaths were observed in 68% of patients and 48% died of progressive IFD. High-dose corticosteroids prior to GM-CSF (OR 24; 95% CI 2.21-264.9; p