Temporal gamma-interferon administration for allergies

Methods for the treatment of allergic reactions are provided, wherein a pharmaceutically effective dose of gamma interferon is administered to a patient within a predetermined temporal period prior to or following exposure to an allergen.

BACKGROUND OF THE INVENTION 
This invention relates to methods for ameliorating allergic immune 
responses. Particularly, according to this invention, natural or 
recombinant gamma interferons are administered within a predetermined 
temporal period prior to suppress a patient's allergic immune response. 
Allergy is a hypersensitivity or altered reactivity to an antigen 
(allergen) that can result in pathologic reactions upon the exposure of a 
sensitized host to that particular antigen. Although the mechanisms 
involved in the induction and control of allergic reactions are not 
completely understood, they have been classified into four types. These 
include immediate hypersensitivity reactions (Type I), toxic effects of 
anticell and antitissue antibodies (Type II), toxic effects of complexes 
between antibody and antigen (Type III), and delayed hypersensitivity 
(cell-mediated) reactions (Type IV). 
In Type I, or immediate-type reactions, a variety of immunologic mechanisms 
may operate, but it is generally believed that they have a mediation 
pathway that involves the release of pharmacologically active substances 
from mediator cells. The antibody which is responsible for immediate 
hypersensitivity belongs to the IgE class of immunoglobulin. IgE 
antibodies bind to receptors on mediator cells such as mast cells and 
basophils. Once the IgE antibody is bound to the receptor, an allergen may 
bind to the antibody, causing the mediator cell to release granules which 
contain the pharmacologically active substances which lead to an allergic 
response. 
These immediate-type reactions are triggered primarily by ingestants (food 
and drugs), injectants (drugs and vaccines) and inhalants (airborne 
organic and inorganic substances). Symptoms include hay fever, food 
allergies, asthma, anaphylaxis, and urticaria. Delayed-type 
hypersensitivity may be triggered by the same kinds of antigens, however 
the increased reactivity to these specific antigens is mediated not by 
antibodies but by T-cells. This type of reaction is seen in some 
autoimmune diseases, and allergic contact dermatitis. 
Current therapy of allergic hypersensitivity centers on avoiding offending 
allergens when feasible, use of appropriate drugs to counteract the 
symptoms, and immunotherapy. The first approach is not always practicable, 
and the second is only useful on a short-term basis. Additionally, the 
effectiveness of drugs such as antihistamines can be limited by side 
effects such as drowsiness and impaired mental acuity. Similarly, the use 
of corticosteroids may be limited by the appearance of local and/or 
systemic toxicity. The use of parenteral immunotherapy has been limited by 
the potential for systemic allergic reactions including anaphylaxis, as 
well as the amount of time to reach maintenance doses and the overall 
duration of the therapy. 
As an alternative therapeutic approach, it has been suggested to interfere 
in vivo with the stimuli that act on the B lymphocytes that are essential 
for the production of IgE. The literature demonstrating this approach are 
inconclusive, because the studies involve inducing polyclonal responses 
rather than clearly antigen-specific IgE responses. Finkelman et al., J. 
Immunol 141:2335 (1988); Finkelman et al., J. Immunol. 137:2878 (1986); 
Katona et al., J. Immunol. 140:3206 (1988); Finkelman et al., J. Immunol 
142:403 (1989). 
Several in vitro studies have suggested that gamma interferon inhibits the 
production of IgE and thus may suppress an allergic response. See, for 
example, Coffman et al., J. Immunol. 136:949 (1986); Snapper et al., 
Science 236:944 (1987); Coffman et al., Immune Regulation by Characterized 
Polypeptides, Alan R. Liss, Inc. 523-532 (1987); DeFrance et al., J. Exp. 
Med. 165:1459 (1987); and Hudak et al., PNAS 84:4606 (1987). These in vivo 
studies share the same basic defect as the in vivo studies discussed 
above, in that the involve polyclonal responses rather than clearly 
antigen-specific IgE responses. For example, in an in vivo study, 
Finkelman et al., J. Immunol. 140:1022 (1988) demonstrate that gamma 
interferon may suppress the polyclonal, anti-immunoglobulin, immune 
response in mice stimulated by the injection of a goat antibody to mouse 
IgD, which by itself induces large increases in levels of serum IgE and 
increases in other immunoglobulins. 
A few studies have proposed to treat allergies by administering gamma 
interferon to a patient in the course of an allergic response, however 
these studies are anecdotal, and either inconclusive or contradictory. 
Australian Patent Application AU-A-48412/85 describes the administration 
of a gamma interferon to a patient with a food allergy. The patient 
received subcutaneous injections of 0.1.times.million I.U. of a gamma 
interferon formulation once a week for four weeks. It is stated that the 
patient's allergy was resolved after the first injection and this 
improvement lasted for six months after the last injection. The protocol 
does not indicate whether or how the patient's reaction to the antigen was 
challenged, or how recently before the treatment the patient had been 
exposed to the antigen. 
PCT Application WO 87/01288 also claims the use of gamma interferon for 
treatment of allergies. This application appears to present the same study 
as Parkin et al., Br. Med. J. [Clin. Res.] 294:1185 (1987). They describe 
the administration of 10 and 3,000 micrograms/M.sup.2 of gamma interferon 
to AIDS patients. While some of the patients found their allergic symptoms 
were apparently ameliorated, these patients also developed increased 
immediate and delayed hypersensitivity to common allergens. It is also 
indicated that other individuals in the study developed different allergic 
sensitivities over the course of the treatment. The observations are 
anecdotal, and the study provides little specific information on the 
challenge with the target antigen. 
Two recent clinical trials of gamma interferon administration for allergies 
reveal contradictory data. In an anecdotal report, Boguniewicz et al., J. 
Allergy and Clin. Immunol 83:307 (100) (1989) disclose the treatment of 14 
atopic dermatitis patients with gamma interferon. No placebo controls were 
included. Symptoms appeared somewhat ameliorated in some of the patients, 
serum IgE did not decrease, and spontaneous IgE production of peripheral 
blood lymphocytes decreased. 
A more extensive published trail of gamma interferon with allergic patients 
is described in Li et al., J. Allergy and Clin. Immunol. 83:307 (543) 
(1989), which documents the double-blind, placebo-controlled trial of 
recombinant gamma interferon with forty-five adults having documented 
ragweed hay fever. This study seems to indicate that gamma interferon had 
little or no effect. There were no sinificant differences between the 
control and treated groups in mean weekly symptom scores, supplemental 
medication scores or hay fever scores, and preliminary inspection of the 
weekly IgE antibody measurements to crude ragweed extract suggested no 
marked differences among the groups. 
In all of these studies, the dosages of gamma interferon and method and 
timing of its administration vary widely, as do the results. There remains 
a need for a treatment for allergies which avoids the disadvantages of the 
conventional methods and the inconsistencies of published methods of using 
gamma interferon, and yet provides effective treatment for allergic 
hypersensitivity. 
It is an object of this invention to provide an effective therapy for 
patients suffering from allergies. 
It is a further object of this invention to provide a means of preventing 
the occurrence of allergic reactions. 
It is another object of this invention to increase the therapeutic efficacy 
of gamma interferon in vivo. 
SUMMARY OF THE INVENTION 
The objects of this invention are accomplished by a method comprising 
treating a patient known to be susceptible to an allergic response by the 
administration of a pharmaceutically effective dose of gamma interferon to 
the patient within a predetermined temporal period prior to or following 
exposure to an allergen, which period is sufficient to suppress the 
allergic response in the patient upon subsequent exposure to the allergen. 
Surprisingly, this method of administration was found to result in 
consistent suppression of IgE response. 
In one embodiment, gamma interferon was administered to an animal model for 
hyperimmunoglobulinemia E concurrent with or within approximately 3 days 
following exposure to the allergen, with a resulting suppression of IgE 
titer. 
Gamma interferon may be administered along with additional anti-allergy 
therapeutic agents such as antihistamines or corticosteroids. It may also 
be administered along with a substance synergistic with gamma interferon 
in immunomodulatory assays, or which has synergistic anti-tumor or 
anti-viral effects, such as TNF-.alpha. or TNF-.beta..

DETAILED DESCRIPTION 
As used herein, "gamma interferon" refers variously to all forms of gamma 
interferon as are known to be biologically active in accepted of gamma 
interferon assays, such as by inhibition of encephalomyocarditis virus 
replication in A549 cells (human lung carcinoma cell line), induction of 
class II antigens, heat lability, other antiviral and antitumor assays, or 
neutralization by antibodies having immunoreactivity for gamma interferon 
but not alpha- or beta-interferon, and is meant to include gamma 
interferon in a mature, pro, met or des (1-3) form, whether in the form of 
natural human gamma interferon, recombinant human gamma interferon, or 
related gamma interferon substances (e.g., non-human gamma interferons). A 
complete description of the preparation of recombinant human gamma 
interferon including its DNA and amino acid sequences is shown in U.S. 
Pat. No. 4,762,791. Amino acid, glycosylation and other variants or 
derivatives are included within this definition. It is expected that other 
variants and derivatives will become available in the future, and these 
are to be considered to fall within the scope of this invention. 
It is currently believed that gamma interferon serves to down-regulate 
Interleukin-4, which is in turn involved in the up-regulation of IgE. 
Therefore, compositions which have the effect of down-regulating 
Interleukin-4, and compositions which are synergistic with gamma 
interferon in immunomodulatory assays, are encompassed within the scope of 
this invention. 
TNF, as employed herein, refers, in general to the various forms of TNF 
which exhibit one or more biologic properties of tumor necrosis such as 
tumor cell lysis, inhibition of infectious agents, class II antigen 
induction and neutralization by antibody to TNF-.alpha. or TNF-.beta. 
(lymphotoxin) but not by antibodies to other cytokines. It is believed 
that TNF is synergistic with gamma interferon in anti-tumor or antiviral 
assays for gamma interferon, and may therefore be desirably administered 
along with gamma interferon in the practice of this invention. 
The formulations may contain agents such as antihistamines and 
corticosteroids previously suggested for use in allergy treatment. Gamma 
interferon also is suitably formulated together with known agents in order 
to modify or enhance the half-life or therapeutic activity of the 
interferon. 
Gamma interferon is placed into sterile, isotonic formulations together 
with required cofactors. The formulation of gamma interferon is preferably 
liquid, and is ordinarily a physiologic salt solution or dextrose 
solution, together with conventional stabilizers and/or incipients. The 
composition may also be provided as lyophilized powder. Saline is a 
suitable carrier, although other conventional parenteral solutions or 
buffers are usable. 
In a pharmacologic sense, in the context of the the present invention, a 
therapeutically effective amount of gamma interferon refers to that amount 
effective to suppress the production of IgE by the B lymphocytes. The 
therapeutically effective dosage of gamma interferon to be administered to 
a human patient generally will range from about 5.times.10.sup.5 to 
5.times.10.sup.6 units per dose, although the dose of the gamma interferon 
administered will be dependent upon the species of the patient, the 
properties of the gamma interferon employed, e.g. its activity and 
biological half-like, the concentration of the interferon in the 
formulation, the rate of dosage, the clinical tolerance of the patients 
involved, the pathological condition of the patients and the like, as is 
well within the skill of the physician. It will be appreciated that the 
practitioner will adjust the therapeutic dose in line with clinical 
experience for any given gamma interferon. 
In the practice of the invention, compositions which include a 
therapeutically effective amount of gamma interferon are administered to 
patients known to be susceptible to an allergic immune response. 
Accordingly, in the practice of this invention, the gamma interferon, 
alone or with other agents as described above, is administered to a 
patient within a predetermined temporal period prior to or preferably, 
following the exposure to an allergen, which period is sufficient to 
suppress the allergic response in the patient upon subsequent exposure to 
the allergen. 
It will be understood that the critical aspect of this invention resides in 
appreciating that the time of administration of gamma interferon in 
relation to intentional or adventitious exposure to allergen is 
determinative of whether the IgE response to the allergen will be 
up-regulated or down-regulated. For each animal species and man the 
critical period may vary from that shown herein for a murine model, i.e. 
it may be greater or longer than 3 days, or it may have a more narrow 
window of efficacy, e.g. 1-2 days. 
The exact administration parameters suitable for any given patient or 
animal species will be determined by routine experimentation. Typically, 
the patient is first exposed to allergen, e.g. by subcutaneous, oral, or 
inhalation administration, and thereafter gamma interferon is administered 
in single or clustered doses at a predetermined time. The patient is 
observed for symptoms of hyperallergic response and for IgE induction. If 
the initial study is unsuccessful another point, usually single, of 
temporal administration is chosen and the process repeated with that 
variable. It is believed that the temporal effect will be largely constant 
within a given species, and may be constant among species. 
It is envisioned that the gamma interferon is administered as substantially 
a single dose, although multiple dosages are within the scope of this 
invention. Injections may be intraperitoneal, intracutaneous, 
subcutaneous, intravenous, and intramuscular. It is presently preferred to 
administer the gamma interferon in an aerosol suitable for inhalation. 
In one preferred embodiment, a patient who has been exposed to an allergen 
on at least two prior occasions is exposed again to that allergen, with 
that exposure being concurrent with or followed within up to about three 
days by administration of gamma interferon. 
In other embodiments, a patient who has been exposed to an allergen on at 
least one prior occasion is exposed again to that allergen, with the 
patient receiving an administration of gamma interferon within a temporal 
period extending from about 4 days prior and 4 days subsequent to the 
allergen exposure. 
This invention encompasses the predetermined exposure of the patient to an 
allergen, including by administration of that allergen to the patient. 
Thus it may be seen that the method of this invention may be utilized 
concurrently with standard desensitization therapy. 
It is also envisioned that the method of this invention may be repeated a 
plurality of times from about four to six weeks apart. 
The method of this invention may be used to treat patients, including cats, 
dogs, and humans. Patients having Acquired Immune Deficiency Syndrome 
ordinarily are excluded from the scope of this invention. According to 
this invention, patients from differing species are all treated by the 
pharmaceutically acceptable administration of gamma interferon in a 
pharmaceutically effective dosage and for a period of time sufficient to 
ameliorate and suppress the allergic response in the patient upon 
subsequent exposure to an antigen. 
In order that the invention described herein may be more fully understood, 
the following example is set forth. It should be understood that this 
example is for illustrative purposes only, and is not to be construed as 
limiting this invention in any manner. 
EXAMPLE 
Materials and Methods 
Immunizations: (C57BL/6.times.DBA/2) F.sub.1 (BDF.sub.1) mice were 
immunized by an intraperitoneal (ip) injection of 0.5 .mu.g DNP.sub.2 OA 
absorbed to 1 mg aluminum hydroxide gel (alum). Groups of mice were 
treated with 10.sup.5 units of recombinant murine gamma interferon by 
injecting 0.1 ml of the appropriate dilution ip, intramuscular (im), or 
intravenous (iv) as indicated in the individual experimental protocols. 
The experimental schedules for these experiments are shown in FIG. 1. 
Twenty-four animals were in each treatment group. 
Measurements of anti-DNP antibodies 
IgE: Anti-hapten IgE antibodies were titrated by passive cutaneous 
anaphylaxis (PCA) reactions in Sprague Dawley Rats. Twofold dilutions of 
the test mouse serum were injected intracutaneously and the reaction was 
elicited after a 4 hr sensitization period by an iv injection of 2.5 mg 
DNP.sub.6 -HSA (dinitrophenyl-human serum albumin) in 0.5 ml of 10% Evans 
Blue dye. 
IgG: IgG anti-DNP antibodies in the test mouse sera were measured by an 
ELISA (Enzyme-linked immunoassay) using serum of anti DNP-OA primed mice 
as a reference standard. The ELISA was set up in 96 well plates. Each well 
was coated with 0.1 ml of 2.5 .mu.g/ml DNP.sub.6 HSA for 24 hrs at 
4.degree. C. After blocking with 0.1% BSA, 0.1 ml of each test sera was 
added to the antigen coated plates in triplicate and the plates were 
incubated for 2 hrs at room temperature. The plates were washed 3x with 
PBS/0.02% Tween 20 and 0.1 ml of a 1:2000 dilution of rabbit anti-mouse 
IgG (Cappel Labs) was added to each well. Plates were again incubated 2 
hrs and washed. Next 0.1 ml of a 1:1600 dilution of Goat anti-Rabbit 
Horseradish peroxidase-conjugated antiserum was then added to each well 
for 1 hr at room temperature. After washing, 0.1 ml of 0.2 mg/ml OPD 
(orthophenyl diamine), 0.01% H.sub.2 O.sub.2 in 0.05M citrate buffer was 
added to each well, the reaction was stopped with 2M H.sub.2 SO.sub.4 
after 30 minutes, and the OD was read at 490 nm on a Microtect plate 
reader. 
Results 
Primary (1.degree.) Response 
As can be seen in FIG. 3A, the results of these experiments suggest that 
gamma interferon can augment the priming of an in vivo IgE response. This 
augmentation appears to be independent of the route (ip vs. im vs. iv) of 
injection or the number of doses (1, 2, or 3) of gamma interferon (FIG. 
3B). Furthermore, if animals receive a second challenge with the antigen, 
the secondary (2.degree.) IgE response is also enhanced compared to 
controls. 
Secondary (2.degree.)/Tertiary (3.degree.) Response 
The results of these experiments suggest that gamma interferon can suppress 
antigen (allergen) driven IgE responses when administered in close 
proximity to antigen challenge. As shown in FIG. 4, in the case of the 
2.degree. response, when gamma is administered before antigen boost (0-4 
days) or after boost (0-3 days), the IgE response to the antigen is 
significantly depressed compared to controls. In contrast, in the case of 
the 3.degree. response shown in FIG. 5A, only administration of gamma 
interferon, after the boost (1-3 days) significantly depresses IgE 
responses. The clinical significance of these findings is that gamma 
interferon, if administered at the proper time following antigen 
challenge, reduces levels of IgE and therefore decreases the symptoms 
mediated by IgE triggering of mast cell/basophil degranulation. In 
addition, since the IgG response to the antigen, shown in FIG. 5B and 
FIGS. 2A and 2B, is unaffected by this treatment, and allergen 
desensitization shots operate under the principle that these shots 
decrease IgE levels while increasing IgG levels, gamma interferon may be 
useful as an adjunct to this form of therapy.