Topical Use of Antibodies for Prevention or Treatment of Pseudomonas Infections

This disclosure is concerned generally with the prevention or treatment of infections and specifically with the topical application of antibodies to prevent or treat infections.

Various antibody preparations have long been used to prevent or treat infections, and the preparations have been administered intramuscularly (IM) and intravenously (IV). In addition, there have been reports of topical administration of immunoglobulins to treat infections. See, for example, the topical use of immunoglobulins against viruses, Akerfeldt et al., Biochemical Pharmacology, Vol. 22, pp 2911-2917, Pergamon Press, 1973. See also the intranasal use against group A streptococci, Bessen et al., J. Exp. Med., Vol. 167, pp 1945-1950, June, 1988; the use of anti-RSV, Hemming et al. Antimicrobial Agents and Chemotherapy, pp 1269-1276, Aug. 1988; and use of antibodies against Mycoplasma pulmonis, Taylor et al., Immunology, 43, pp 519 et seq., 1981. See, also, recently issued U.S. Pat. No. 4,800,078 to G. Prince et al. (aerosol application of anti-RSV antibodies). To date, however, we are unaware of the topical application of antibody preparations to prevent or treat infections of Pseudomonas aeruginosa.

Nosocomial pneumonia is a common infection in the debilitated intensive care unit (ICU) patients. P. aeruginosa infection is a frequent cause of nosocomial pneumonia, and mortality associated with P. aeruginosa infection is approximately 70%. This death rate is about twice as high as that seen with other common ICU respiratory pathogens such as Staphylococcus, Klebsiella and Serratia.

Since the publication of the article by Kohler and Milstein, "Continuous Cultures of Fused Cells Secreting Antibody of Predefined Specificity," Nature 256:495-497 (1975), the production of monoclonal antibodies has become known and attention has been given to tailor-making high titer antibody preparations directed to a very specific antigen or a few antigens of a specific pathogen. This is being done with the hope that a highly effective prophylactic or therapeutic product will be possible for use against a very specific infection.

To avoid confusion regarding terminology, antibodies made from single cells such as the hybridomas of Kohler et al. or the later transformed cells of others (e.g. U.S. Pat. No. 4,446,465 to M. Lostrom) are all referred to as monoclonal antibodies, even if several different such antibodies are combined in a so-called cocktail (e.g. as in U.S.S.N. 734,624 filed May 15, 1985, now U.S. Pat. No. 4,834,975 filed in the name of A. Siadak et al.) describing a collection of monoclonal antibodies that bind to different antigenic determinants of P. aeruginosa. Plasma derived (Pd) antibodies are referred to as polyclonal, to describe both their wide variety and their plasma source. This also distinguishes them from monoclonal antibodies (MAbs).

By their very nature, each monoclonal antibody is directed against and binds with a single epitope on a micro-organism or other antigen. Depending upon the nature and site of the epitope, the antibody may be defined as protective or not protective.

We have found that topical application of antibodies such as intravenous IgM or IgG (IGIV) or high titered Pseudomonas intravenous IgG (Ps. IGIV) to the respiratory tract is highly effective in reducing mortality associated with such infections (e.g. P. aeruoinosa pneumonia). Our invention is especially useful when the Pseudomonas antibodies are of the IgM type which, because of their size, are difficult to deliver to the lungs via conventional systemic routes. Details of our findings are described below.

Our method of preventing or treating an infection in a mammal caused by P. aeruginosa comprises the step of topically applying to the site of infection in the mammal a preparation comprising antibodies that can bind to an antigen of the organism, the amount of antibodies being sufficient to prevent or treat the infection. In one preferred embodiment, an antibody preparation having a relatively high titer of antibodies to P. aeruoinosa of at least five times the normal or average titer (at least about 1 1600) is applied intranasally to treat a P. aeruginosa pneumonia. Such preparation is described by Collins and Roby, U.S. Pat. No. 4,801,450, for example, and incorporated herein by reference thereto. In another embodiment, the antibodies are administered in the form of an aerosol to the mammal's lungs. A preferred dosage for polyclonal antibody preparations ranges from about 2 mg/kg to about 100 mg/kg of body weight of the mammal, and the antibodies are part of an immune serum globulin (ISG) having an ISG content ranging from about 0.5 to about 17% on a wt/wt basis in water. A preferred dosage for monoclonal antibody preparations ranges from about 0.02 mg/kg to about 1.0 mg/kg of body weight. The antibody preparations of this disclosure may be available in a liquid form or a freeze dried form which can be reconstituted with an appropriate diluent. As used herein, the term topical, or its equivalent, means the application of antibodies to lung and airway mucosa by application via the respiratory tract (e.g. inhalation via a nebulizer or injection via a tracheal tube or bronchoscope, etc.).

As used herein, the term protective or its equivalent means capable of reducing cumulative mortality in infected animals and/or reducing bacterial inoculum within the lungs.

The term pathogen or its equivalent means a bacterium capable of causing infection in a suitable host.

Antibody preparation or its equivalent means a composition comprising antibodies from any source (e.g. plasma or monoclonal antibodies) and capable of protective binding with antigens of P. aeruoinosa bacteria.

Our invention is illustrated with the following examples showing the intranasal application of a high titer Ps. ISG (Ps. IGIV), a conventional IGIV, a serum IgM preparation and human IgM monoclonal antibodies.

A 50 .mu.l volume of 5% IGIV (Gamimune.RTM.-N) or Ps. IGIV (Ps. titer at least about 1:1600) was applied to the nares of anesthetized mice. Because mice are obligate nasal breathers, the majority of the IGIV solution was aspirated into the lungs. Twenty minutes later 50 .mu.l of Pseudomonas aeruginosa inoculum was applied to the nares; this was also aspirated into the lungs. Data in the following Tables indicate this treatment and similar treatment using monoclonal antibodies were highly effective in promoting survival in infected mice.

In yet another experiment, we found that a plasma derived IgM preparation was similarly protective, as shown in Table 6, below. The plasma IgM was prepared in accordance with commonly assigned patent application Ser. No. 203,377, filed in names of Collins et al. and entitled, Therapeutic IgM Concentrates. The actual plasma derived IgM product consisted of about 0.8% wt/vol protein solution, containing about 95% IgM with trace amounts of IgA and IgG antibodies. The solution was at pH 4.8 and included 0.25 M glycine as a stabilizer.

Our data indicate that topical immunoglobulin is highly effective in preventing mortality associated with Pseudomonas pneumonia. For prevention of Pseudomonas pneumonia in high-risk hospital patients, immunoglobulin could easily be administered by aerosol (via nebulizer). Similarly, topical immunoglobulin may be useful in preventing recurrent pneumonia in patients with cystic fibrosis whose lungs are chronically colonized with P. aeruginosa. Furthermore, serum immunoglobulin or monoclonal antibodies, could be specifically formulated with suitable pharmaceutically acceptable excipients for aerosol administration.

It is thought that a topical or aerosol administration of antibodies specific to P. aeruginosa would be similarly effective using a wide variety of excipients or vehicles to assure even and non-detrimental distribution of the antibody preparation. These could be readily formulated by those skilled in the art.

As noted above, our method is especially advantageous in administering antibodies of the IgM type directly to the lung. Also, our method permits ease of use, and less antibody is needed since it is not delivered systemically. In addition, our method avoids trauma, prevents sepsis or injuries associated with venipuncture, is faster and can be used in cases where an IV administration is very difficult (in cases of collapsed veins or for obese people whose veins are difficult to find).

Given the above disclosure, it is thought that variations will occur to those skilled in the art. Accordingly, it is intended that the invention disclosed here should be limited only by the following claims.