Induction of accessory cell function of human alveolar macrophages by inhalation of human natural interleukin-2

Pharmacokinetics of inhaled nanotherapeutics for pulmonary delivery

Pulmonary delivery of lipid-based nanotherapeutics by inhalation presents an advantageous alternative to oral and intravenous routes of administration that avoids enzymatic degradation in gastrointestinal tract and hepatic first pass metabolism and also limits off-target adverse side effects upon heathy tissues. For lung-related indications, inhalation provides localized delivery in order to enhance therapeutic efficacy at the site of action. Optimization of physicochemical properties, selected drug and inhalation format can greatly influence the pharmacokinetic behavior of inhaled nanoparticle systems and their payloads. The present review analyzes a wide range of nanoparticle systems, their formulations and consequent effect on pharmacokinetic distribution of delivered active components after inhalation.

Therapeutic approaches in metastatic renal cell carcinoma: local immunotherapy

Since 1990, aerosol interleukin (IL)-2 has been used to treat pulmonary metastatic renal cell carcinoma (pmRCC). Inhalation therapy deposits a drug into the airways to achieve a high, local, clinical effect while avoiding serious systemic side effects. We report three studies to describe safety and efficacy of aerosol IL-2 in patients with pmRCC. In a multicenter study, 24 patients received exclusive inhalation (study I) of natural IL-2 (three dose levels, 48 weeks) and response and toxicity were evaluated. The survival of high-risk patients (study II) with mainly inhaled IL-2 (n=94) was compared with that of patients receiving systemic IL-2 (n=103). In ten patients we analyzed in detail lung function and markers of airway inflammation before and during inhalational IL-2 therapy (study III). Study I: The response of exclusive inhalation was 33.3% at 3 months and 16.7% at 6 months. Treatment was well tolerated, cough being the most frequent adverse event. Study II: The probabilities of survival at 5 years were 21% for the inhalational group and 0% for the systemic group. Study III: Inhaled IL-2 induced a moderate decline of forced expiratory volume (FEV), while exhaled nitric oxide (NO) and sputum eosinophils rose accompanied by moderate cough and dyspnea. In conclusion, inhalational IL-2 combines good efficacy and improves tolerability. This is especially important for patients who are not able to benefit from systemic IL-2 therapy. Whether the local eosinophilic response additionally supports the antitumor effect remains a challenging question.

Inhalational interleukin-2 liposomes for pulmonary metastases: a phase I clinical trial

The lung is a common site of both metastases and primary neoplasia. This phase I study was designed to test the feasibility and toxicity of administering interleukin (IL)-2 liposomes by aerosol to patients with pulmonary metastases. The goal was to test whether IL-2 liposomes could be given by aerosol using biologically effective but non-toxic doses in an outpatient setting. Liposomes containing IL-2 or placebo (buffer) were synthesized and mixed to provide a constant lipid dose, and were nebulized using a Puritan twin jet nebulizer and a standard compressor. The liposome-containing mist was inhaled for about 20 min 3 times a day in order to selectively stimulate immune function within the lung and to avoid systemic toxicity. The dose chosen was based on canine efficacy and toxicity studies that used bronchoalveolar lavage to demonstrate increased cell numbers and activation of mononuclear cells after inhalation of nebulized IL-2 liposomes. Nine patients were treated in three cohorts of three patients at 1.5, 3.0 and 6.0 x 10(6) IU of IL-2 3 times a day. No significant toxicity was observed. We conclude that the delivery of IL-2 liposomes by inhalation is well tolerated. Further studies of inhalational IL-2 liposomes to determine efficacy as an anti-cancer therapy are warranted.

Accessory function and costimulatory molecule expression of alveolar macrophages in patients with pulmonary tuberculosis

An effective immune response against M. tuberculosis requires a coordinated interaction of alveolar macrophages (AM) and lymphocytes. Secondary signals, such as accessory function (AF) of antigen presenting cells and interaction of costimulatory molecules are also important for T cell activation. In the present study we determined the AF and the expression of CD11a, CD54, CD58, CD80, CD86 and HLA-DR costimulatory molecules by AMs lavaged from patients with pulmonary tuberculosis and controls. We hypothesized that alterations in AF and costimulatory molecule expression may influence the presentation of tuberculosis. Therefore these parameters were also correlated with the radiographic extension of the disease. AMs of patients with tuberculosis exhibited an increased AF and a significantly increased expression of co-stimulatory molecules compared with controls. Furthermore, we observed that the expression of CD54 (ICAM-1) decreased with the course of the disease. We conclude that the infection by M. tuberculosis results in an increased AF of AMs and the activity of AMs remains uninfluenced by the extension of the disease. Clear-cut changes of patterns of costimulatory molecule expression by AMs could not be observed with the progression of tuberculosis.