The mortality rate of alveolar hemorrhage following allogeneic hematopoietic stem cell transplantation is greater than 60% with supportive care and high dose steroids. We performed a retrospective cohort analysis to assess the benefits and risks of rFVIIa as a therapeutic adjunct for alveolar hemorrhage. From 2005 to 2012, 57 episodes of alveolar hemorrhage occurred in 37 patients. Fourteen episodes (in 14 patients) were treated with steroids alone and 43 episodes (in 23 patients) were treated with steroids and rFVIIa. The median (interquartile range) steroid dose was 1.9 mg/kg/d (0.8 – 3.5; methylprednisolone equivalents) and did not differ statistically between the two groups. The median rFVIIa dose was 41 μg/kg (39-62) and a median of 3 doses (2-17) was administered per episode. Concurrent infection was diagnosed in 65% of the episodes. Patients had moderately severe hypoxia (median PaO2/FiO2, 193 [141-262]); 72% required mechanical ventilation and 42% survived to extubation. The addition of rFVIIa did not alter time to resolution of alveolar hemorrhage (p = 0.50), duration of mechanical ventilation (p = 0.89), duration of oxygen supplementation (p = 0.55), or hospital mortality (p = 0.27). Four possible thrombotic events (9% of 43 episodes) occurred with rFVIIa. rFVIIa when used in combination with corticosteroids did not confer clear clinical advantages compared to corticosteroids alone. In patients with AH following hematopoietic stem cell transplant, clinical factors (i.e. worsening infection, multiple organ failure or recrudescence of primary disease) may be more important than the benefit of enhanced hemostasis from rFVIIa.

We have recently shown that donor CD4-enriched cells of Th2 cytokine phenotype, generated by treating mice in vivo with a combination of interleukin-2 (IL-2) and IL-4, prevent lipopolysaccharide-induced, tumor necrosis factor-alpha-mediated lethality during graft-versus-host reaction. To assess the potential regulatory role of such Th2-type cells in lethal graft-versus-host disease (GVHD) and graft rejection, we used a fully allogeneic murine transplant model using sublethally irradiated hosts (B6-->C3H, 500 cGy). Such recipients generated a strong host-versus-graft response, as reflected by their ability to reject T-cell-depleted inocula. The administration of T-cell-containing donor whole spleen inocula resulted in alloengraftment, but such recipients developed lethal GVHD. However, mice receiving sequential donor whole spleen (day 0) and CD4-enriched, Th2-type (day 1) populations engrafted, and had prolonged survival with protection from histologically defined tissue injury associated with GVHD. The findings in this fully allogeneic model thus extend our previous observations and indicate that the transfer of donor Th2-type cells may be an important strategy for regulating GVHD. Furthermore, the sequential “Th1(-)-->Th2-type” donor cell transfer described in this report represents a novel approach for abrogating graft rejection with concomitant control of GVHD and illustrates the importance of kinetics in the interaction of functionally distinct donor T-cell populations.

Recent investigations have demonstrated that adenoviral and lentiviral vectors encoding HER-2 can be utilized in cancer immunotherapy. However, it is not known whether both viral systems elicit a similar immune response. Here, we compare the immune response in mice induced by dendritic cells (DCs) infected with either recombinant adenovirus or lentivirus encoding rat HER-2 (rHER-2). Both vaccine types yielded similar control of tumor growth, but we found clear differences in their immune responses 10 days after DC immunization. Adenovirus rHER-2-transduced DCs elicited locally and systemically high frequencies of CD4+ and CD8+ T cells, while lentivirus rHER-2-transduced DCs predominantly led to CD4+ T-cell infiltration at the tumor site. Splenocytes from mice immunized with lentivirus rHER-2-transduced DCs secreted higher levels of interferon (IFN)-γ, mainly by CD4+ T cells, following stimulation by RM-1-mHER-2 tumors. In contrast, the adenovirus vaccinated group exhibited CD4+ and CD8+ T cells that both contributed to IFN-γ production. Besides an established cellular immune response, the rHER-2/DC vaccine elicited a significant humoral response that was highest in the adenovirus group. DC subsets and regulatory T cells in the spleen were also differentially modulated in the two vaccine systems. Finally, adoptive transfer of splenocytes from both groups of immunized mice strongly inhibited in vivo tumor growth. Our results suggest that not only the target antigen but also the virus system may determine the nature and magnitude of antitumor immunity by DC vaccination.