Jan M. Agosti

Transfer of allergen-specific IgE-mediated hypersensitivity with allogeneic bone marrow transplantation

We investigated whether allergen-specific IgE-mediated hypersensitivity is transferred by bone marrow transplantation. Twelve patients, 14 to 47 years of age, undergoing allogeneic bone marrow transplantation for the treatment of hematologic cancer were selected, along with their donors, by a screening questionnaire for a history of atopy in the donor. We evaluated these donor-recipient pairs before transplantation and at several points afterward for immediate skin-test reactivity to 17 allergens. For allergens for which pretransplantation skin tests had been positive in the donors and negative in the recipients, 20 of 46 post-transplantation skin tests were positive in 8 of the 11 recipients who survived for more than one year after transplantation. For allergens for which both donors and recipients had had negative skin tests before transplantation, only 6 of 256 tests (2.3 percent) were positive in the recipients after transplantation. Long-term transfer of donor-derived mite-specific IgE was demonstrated by radioallergosorbent testing in two recipients. Seven recipients either acquired or had an exacerbation of allergic rhinitis, and two recipients without a history of asthma had asthma one year after transplantation. We conclude that allergen-specific IgE-mediated hypersensitivity is adoptively transferred by bone marrow transplantation from donor to recipient by B cells with allergen-specific memory.

Effects of Anti‐inflammatory Agents on Serum Levels of Calcitonin Precursors during Human Experimental Endotoxemia

Calcitonin precursor (CTpr) levels are both markers and mediators of inflammation. The duration of their elevation after intravenous endotoxin challenge and the effects of anti-inflammatory therapies were studied in 52 subjects. CTpr levels maximized at 24 h in all subjects. At 7 days (n=4), after levels of acute-phase cytokines and C-reactive protein had normalized, CTpr levels remained 2-4-fold above baseline levels. The elimination half-life of CTpr levels ranged from 26.9 to 45.7 h. At 24 h, endotoxin and ibuprofen (compared with endotoxin alone) increased CTpr levels approximately 2-fold (P=.03), whereas soluble tumor necrosis factor receptor blunted the increase in CTpr levels by 2-3-fold (P=.0015). However, soluble interleukin-1 receptor failed to alter the increase in CTpr levels. Thus, the fact that anti-inflammatory agents may alter CTpr levels resulting from a single stimulus must be considered when CTpr is used as a clinical marker. Of importance, this study reveals that anti-inflammatory agents may modulate the CTpr level, which is a potential toxic mediator of inflammation.

Hepatitis B immunization of healthy elderly adults: relationship between naïve CD4+ T cells and primary immune response and evaluation of GM-CSF as an adjuvant.

The efficacy of granulocyte–macrophage colony-stimulating factor (GM-CSF) to enhance the primary immune response to hepatitis B vaccine was studied in healthy elderly with young volunteers included as controls in this double-blind, placebo-controlled trial of GM-CSF as an immune adjuvant. Na¨ıve T-helper cells (CD4+CD45RA+) were determined at baseline. Forty-five healthy elderly (average age, 74 years) and 37 healthy young controls (average age, 28 years) were randomized. Hepatitis B vaccine was administered at 0, 1, and 6 months. GM-CSF as a single injection of either 80 μg or 250 μg with the first and second doses of hepatitis B vaccine. In this trial GM-CSF did not enhance antibody responses. However, the antibody responses were dramatically different between these two groups: 35/35 young developed a protective titer versus 19/45 elderly (P < 0.0001). In addition, the mean logarithm of anti-hepatitis B antibody level in the 35 young who completed the study was 3.17 (log mIU/ml) but only 2.21 in the 19 elderly responders (P < 0.0001). Na¨ıve T-helper cells differed significantly between the two groups: the mean percentage of CD4+CD45RA+ T cells was 47.9% versus 35.0% (P < 0.0001) in the young and elderly volunteers respectively. Na¨ıve T cells also differed significantly between elderly who did or did not respond to HBV (39.9% vs. 31.7%, P = 0.039). Using linear regression, age, and percent na¨ıve, CD4 T cells were determined to significantly influence the anti-hepatitis B antibody response, but sex and dose of GM-CSF did not. For a two-parameter model: logarithm of antibody titer = (−0.038 × age in years) + (0.031 × % na¨ıve CD4T cells) + 2.68; adjusted r2 = 0.605 and P < 0.0001. However, age had a larger effect than na¨ıve CD4 T cells, i.e., in comparing young and elderly groups the log antibody titer decreased by 1.73 due to the increase in age but only 0.40 due to the decrease in na¨ıve CD4 T cells. Thus, there was a large effect of age that could not be explained by the quantitative change in the na¨ıve T-helper cells.

Phase III study of granulocyte-macrophage colony-stimulating factor in advanced HIV disease: effect on infections, CD4 cell counts and HIV suppression.

ObjectiveTo evaluate the effect of adjuvant granulocyte-macrophage colony-stimulating factor (GM-CSF) (sargramostim, yeast-derived recombinant human GM-CSF) on incidence and time to opportunistic infection or death, plasma HIV-RNA, and CD4 cell count in patients with advanced HIV disease. MethodsThis Phase III randomized, double-blind, placebo-controlled trial enrolled subjects with CD4 cell counts ⩽ 50 × 106/l or ⩽ 100 × 106/l with a prior AIDS-defining illness on stable antiretroviral therapy. Subjects were stratified by baseline HIV-RNA level (⩾ or < 30 000 copies/ml) and randomized to receive subcutaneous injections of GM-CSF 250 μg or placebo three times per week for 24 weeks. Subjects were permitted to continue on blinded drug for up to 20 months. Subjects were evaluated for infections, plasma HIV-RNA, lymphocyte counts, changes in antiretroviral therapy, toxicity, and survival. ResultsThree-hundred and nine subjects received at least one dose of study drug, 70% completed 24 weeks of therapy. Groups were well matched at baseline. Significant increases in CD4 cell and neutrophil counts were observed at 1, 3, and 6 months in the GM-CSF group. GM-CSF significantly reduced the incidence of overall infections (78% placebo versus 67% GM-CSF;P = 0.03) and delayed time to first infection (56 days placebo versus 97 days GM-CSF;P = 0.04). No statistical difference in cumulative opportunistic infections was observed between groups; however, among subjects without an opportunistic infection prior to study, the GM-CSF group demonstrated a trend towards fewer subjects with an opportunistic infection on study (26% placebo versus 8% GM-CSF;P = 0.08). Change in HIV-RNA was not significantly different between groups, but significantly fewer GM-CSF subjects with baseline viral load < 30 000 copies/ml had changes in antiretroviral therapy for increased viral load (42% placebo versus 21% GM-CSF;P = 0.01). In patients with HIV-RNA levels below the limit of detection at baseline, more GM-CSF patients maintained an undetectable viral load at 24 weeks (54% placebo versus 83% GM-CSF;P = 0.02). GM-CSF was well tolerated. ConclusionsGM-CSF significantly increased CD4 cell count and decreased virological breakthrough and overall infection rate in subjects with advanced HIV disease.

A Randomized, Placebo-Controlled Trial of Granulocyte-Macrophage Colony-Stimulating Factor and Nucleoside Analogue Therapy in AIDS

Preliminary preclinical and clinical data suggest that granulocyte-macrophage colony-stimulating factor (GM-CSF) may decrease viral replication. Therefore, 105 individuals with AIDS who were receiving nucleoside analogue therapy were enrolled in a placebo-controlled, double-blind study and were randomized to receive either 125 microgram/m(2) of yeast-derived, GM-CSF (sargramostim) or placebo subcutaneously twice weekly for 6 months. Subjects were evaluated for toxicity and disease progression. A significant decrease in mean virus load (VL) was observed for the GM-CSF treatment group at 6 months (-0.07 log(10) vs. -0.60 log(10); P=.02). More subjects achieved human immunodeficiency virus (HIV)-RNA levels <500 copies/mL at >/=2 evaluations (2% on placebo vs. 11% on GM-CSF; P=.04). Genotypic analysis of 46 subjects demonstrated a lower frequency of zidovudine-resistant mutations among those receiving GM-CSF (80% vs. 50%; P=.04). No difference was observed in the incidence of opportunistic infections (OIs) through 6 months or survival, despite a higher risk for OI among GM-CSF recipients. GM-CSF reduced VL and limited the evolution of zidovudine-resistant genotypes, potentially providing adjunctive therapy in HIV disease.

Granulocyte Macrophage Colony-Stimulating Factor as an Adjuvant for Hepatitis B Vaccination of Healthy Adults

Granulocyte macrophage colony-stimulating factor (GM-CSF) has shown promise as an adjuvant to improve the kinetics and magnitude of the immune response after vaccination. It was hypothesized that GM-CSF given intramuscularly (IM) with hepatitis B vaccine would result in increased seroconversion rates and antibody titers. In total, 108 healthy volunteers (18-45 years old) received recombinant hepatitis B vaccine IM at 0, 1, and 6 months and were randomized to receive either concurrent GM-CSF (80 or 250 microgram) or placebo IM with the first two vaccinations. The percentages of subjects achieving a protective level of antibody at day 56 were 58.3%, 58.8%, and 58.3% in the placebo and 80- and 250-microgram GM-CSF arms, respectively. The geometric mean titers of antibody measured on days 28, 56, and 189 were not statistically different between arms. GM-CSF given immediately before recombinant hepatitis B vaccination was safe and well tolerated but did not appear to provide significant adjuvant activity at this dose.

The Safety and Efficacy of Granulocyte-Macrophage Colony-Stimulating Factor (Sargramostim) Added to Indinavir- or Ritonavir-Based Antiretroviral Therapy: A Randomized Double-Blind, Placebo-Controlled Trial

Sargramostim is a yeast-derived, recombinant human granulocyte-macrophage colony-stimulating factor with therapeutic potential in human immunodeficiency virus (HIV) infection. Its safety and activity when used in combination with protease inhibitors were evaluated in a randomized, double-blind trial in which 20 HIV-infected subjects on stable antiretroviral regimens, including indinavir or ritonavir, received sargramostim or placebo 3 times a week for 8 weeks. Analysis of HIV virus load excluded any 0. 5 log10 increase due to sargramostim (95% confidence interval, -0.68 to 0.44). Sargramostim was well tolerated, and inflammatory cytokines and surrogate markers of disease progression, such as serum levels of interleukin-10 and soluble tumor necrosis factor receptors types Iota and IotaIota, remained stable in subjects receiving sargramostim. Sargramostim treatment was associated with a trend toward decreased HIV RNA (>0.5 log10) and increased CD4+ cell count (>30%). These results became statistically significant only when subjects with baseline virus loads within the limits of detection or baseline CD4 cell count >50 were analyzed. No difference in indinavir pharmacokinetics was observed before or after sargramostim therapy.

NOVEL THERAPEUTIC APPROACHES FOR ALLERGIC RHINITIS

The last 2 decades have witnessed enormous changes in our understanding of allergic rhinitis. As we have begun to unravel the complex underlying immunologic and inflammatory pathophysiology of the disease, new therapeutic strategies as well as specific molecular and cellular constituents have emerged as potential targets for clinical intervention. These efforts also have shed light on the mechanisms by which current antiallergy medications act—or sometimes fail to be effective. 7,31,51,89 The similar pathophysiologic basis for allergic rhinitis and the often comorbid condition, asthma, was underscored in the recently published American Thoracic Society Workshop Summary on the Immunobiology of Asthma and Rhinitis: Pathogenic Factors and Therapeutic Options. 18 In his conclusion, workshop chair, Thomas Casale, 18 counsels readers to consider that “…allergic asthma and rhinitis represent a systemic disease affecting two organs, the lung and the nose. Asthma and allergic rhinitis share many of the same pathogenic factors, but they operate in different parts of the airway. Inflammatory cells and mediators are often the same, and there may be common alterations that occur in the immune system.” Thus, therapeutic strategies and potential therapeutic agents found to be beneficial in the treatment of one airway target may show similar effects in the other. For this reason, and because many of the therapies now being developed are at early stages in their evolution, physicians interested in rhinitis therapy also must examine what is known about these agents in asthma. One avenue of active research has been the role of leukotrienes and other mediators in the pathophysiology of asthma and rhinitis. Three leukotriene modifiers now have been approved for the treatment of asthma in the United States; their potential use in the treatment of rhinitis has been a focus of considerable speculation and investigation. An early “day in the park” study showed that with antileukotriene therapy, patients with rhinitis had demonstrable improvements in their rhinitic symptoms. 29 Roquet et al 83 reported that in the treatment of asthma, there was a synergistic effect when an antileukotriene agent and an antihistamine were used, compared with either drug alone. A product combining an antileukotriene with an antihistamine is currently under development. The most exciting developments, however, may be in the immunology arena. As described by Baraniuk elsewhere in this issue, the pathophysiology of allergic rhinitis is highly complex. Multiple interacting, interdependent, and redundant pathways and molecular and cellular constituents are involved in the pathogenesis of allergic rhinitis. Briefly, exposure of the nasal mucosa to allergen in a sensitized individual leads to the release and further production of inflammatory mediators and the release of cytokines. 5 These released cytokines activate endothelial cells, thereby inducing expression of adhesion receptors on the cell surface and initiating a cascade of events that facilitates transendothelial migration of inflammatory cells. T lymphocytes also are activated by these cytokines. Within a given tissue, specific patterns of cytokines are released, dependent on the dominant subset of local T lymphocytes. These, in turn, lead to the preferential activation and recruitment of specific inflammatory cells and the characteristic cellular inflammation observed in allergic rhinitis.