Search

A variety of ingenious methods have been devised to challenge and incite episodes of acute allergic rhinitis in susceptible individuals. These methods teach us much about basic mechanisms involved in the disease. There is some danger in using them for efficacy trials because antihistamines are only partially effective treatment for hay fever and the challenge administered could easily overcome the degree of protection. Additional studies may lead to a better understanding of the factors involved in challenges and hence, their usefulness in clinical testing. The out-patient trial design is successful in demonstrating efficacy in 40 to 60 per cent of trials. The field trial is 70 to 90 percent accurate in its findings. The clinical design of antihistamine trials has improved remarkably in the past 10 years. Because of the nature of the disadvantages discussed throughout this report, I would doubt that further improvements in design will occur in future years unless a substitute is found for subjective evaluations.

Azelastine, a novel antiallergic medication, was compared with chlorpheniramine maleate and placebo for efficacy and safety in the treatment of spring allergic rhinitis in a multicenter, double-blind, multiple-dose, parallel-groups study. One hundred fifty-five subjects participated. Subjects ranged in age from 18 to 60 years of age and had at least a 2-year history of spring allergic rhinitis, confirmed by positive skin test to spring aeroallergens. Medications were given four times daily; the azelastine groups received 0.5, 1.0, or 2.0 mg in the morning and evening with placebo in the early and late afternoon; the chlorpheniramine group received 4.0 mg four times daily. Daily subject symptom cards were completed during a screening period to assess pretreatment symptoms and during a 4-week treatment period while subjects received study medications. Individual symptoms, total symptoms, and major symptoms were compared to determine efficacy of medication. Elicited, volunteered, and observed adverse experiences were recorded for each subject and compared among groups. Vital signs, body weights, serum chemistry values, complete blood cell counts, urine studies, and electrocardiograms were obtained for each subject and compared among groups. Symptoms relief in the group receiving the highest concentration of azelastine (2.0 mg twice daily) was statistically greater than in the placebo group during all weeks of the study. Lower doses of azelastine were statistically more effective than placebo only during portions of the first 3 weeks of the study. In contrast, although the chlorpheniramine group did have fewer symptoms than the placebo group during the study, the difference never reached statistical significance during any week of the study. There were no serious side effects in any of the treatment groups. Drowsiness and altered taste perception were increased significantly over placebo only in the high-dose azelastine group. Azelastine appears to be a safe, efficacious medication for seasonal allergic rhinitis.

Two in vitro systems of measuring total IgE and specific IgE antibodies were compared using serum of patients suspected of having allergic rhinitis due to inhalation of grass pollen. One in vitro system was the Phadebas PRIST and RAST. The accuracy of these tests has been well defined and they were used as the standard. The Acti*Tip Allerg*E and Allerg*ENS system is a new technique utilizing a similar solid-phase immunologic methodology with an enzyme-based detection system. It has some advantages primarily related to the mechanics of performing the test and marked reduction in time for obtaining results. The correlation between the Phadebas and Acti*Tip systems was highly significant for measuring total IgE and specific IgE antibodies for grasses in serum.

Antihistamine therapy reduces hay fever symptoms 50–60% within 5 hours after the first dose. Treatment for 9 days maintains but does not reduce symptoms further. Patients treated with placebo for 8 days and then treated with chlorpheniramine obtained as much relief by the 5th hour after treatment as those treated with chlorpheniramine for 9 days. Increasing the dose of any antihistamine we tested over that necessary for maximal relief produces no greater benefit. Antihistamine treatment doses currently recommended may be greater than necessary for most patients. Antihistamines do not reduce nasal congestion and are not decongestants.

Oxymetazoline (Afrin) and pseudoephedrine (Sudafed) were compared by rhinomanometric measurements using nasal airflow, a parameter of nasal airway patency, and therefore airway congestion. Oxymetazoline had a more rapid onset and duration of action, greater improvement in airway patency, and longer action than pseudoephedrine, the best of the oral decongestants. The decongestive effect was more reliable for oxymetazoline with 28 of 29 subjects experiencing some degree of decongestion compared to 21 of 30 for pseudoephedrine. Utilizing a combination of oral and topical decongestants may result in the most logical regimen for treatment of nasal congestion. Oxymetazoline is the drug of choice for night time decongestion.

Injections of aqueous ragweed extract are generally not thought to be capable of sensitizing ragweed-negative skin reactors. A review of our passive transfer recipients showed that of 22 recipients challenged with aqueous ragweed extract on more than two occasions, 3 developed positive ragweed skin tests. One of these recipients became sensitized and lost the sensitivity in time only to become sensitized again when challenged on one occasion.

Acute episodes of allergic rhinitis were produced in the laboratory with quantitated challenges of ragweed pollen. Nasal congestion caused by ragweed inhalation was measured objectively as often as every two minutes during an episode of hay fever. Challenges given one hour daily on four successive days decreased the nasal threshold for allergic rhinitis more than fivefold. This effect is called "priming of the end organ." The priming effect was readily reversed by stopping challenges for several days. It was shown that environmental exposure during the ragweed pollinating season also primed ragweed-sensitive individuals. Reversibility of the priming effect required weeks after seasonal pollen exposure had ceased. In four subjects challenged during the season, the pollen dose which caused an acute episode of allergic rhinitis varied according to skin-sensitizing antibody titer; the higher the titer, the greater the susceptibility. In six ragweed-sensitive subjects tested, neither hay fever symptoms nor nasal congestion followed placebo challenges.

The titers of skin sensitizing antibody of the sera of untreated hay fever patients differ significantly from those of the sera of persons who react to intracutaneous tests with ragweed pollen extract but who do not have clinical hay fever.

Eosinophilia of some degree is associated with many allergic conditions, but the function of the eosinophil in these conditions is not known. This report describes a morphological change, vacuoles in the eosinophil, previously unrecognized in human beings in vivo. Vacuolizaton of the eosinophil occurred more frequently in symptomatic asthmatic patients. It was also found in other allergic conditions such as allergic rhinitis and serum sickness. In a large control population of hospitalized patients, vacuolization of eosinophils was often found associated with those illnesses in which tissue damage played an important role, such as myocardial infarction. In a control group of student nurses, vacuolization of eosinophils was observed only in those patients who had active allergic disease. In a group of healthy nonallergic subjects such eosinophils were rarely seen. The meaning of vacuolization was not established. One hypothesis suggested by the findings is that vacuoles repesent phagocytized foreign protein. In allergic individuals, the protein could be either antigen-antibody complexes or antigen.

1. 1. The severity of hay fever varied according to the titer of skin-sensitizing antibody, the group of patients showing the highest titers of antibody reporting the most symptoms and those with the lowest titers the fewest symptoms. 2. 2. Clinical symptoms were more directly related to the titers of skin-sensitizing antibody than to the type of injection therapy administered. 3. 3. Sex of the patient is not a determinant in the severity of hay fever symptoms.

The “priming effect” has been defined as an increase in reactivity of the nasal membrane following repeated exposures to pollen. Priming is reversible in days to weeks, depending on the degree of exposure to antigen. Additional characteristics of the priming effect were determined by administering ragweed pollen to only one nostril. Such challenges caused unilateral allergic rhinitis. When unilateral challenges were repeated daily they eventually caused priming or a hyperreactivity of the challenged nostril only; the resistance of the contralateral nostril was unchanged. These findings suggest that the priming effect is related to a local change in the challenged tissue rather than a systemic change. After one nostril was primed by repeated daily exposures to ragweed pollen, sorrel pollen—an antigen to which the patient had a positive skin test but which did not provoke symptoms during normal environmental exposure—was administered on the same day to both the primed and unprimed nostrils. Severe rhinitis occurred in the primed nostril during minimal exposure to this antigen; no symptoms occurred in the unprimed nostril despite a tenfold increase in the pollen dose. Evidence is presented indicating little or no cross-reactivity between ragweed and sorrel. These findings suggest that priming is nonspecific.

Skin-sensitizing antibody in low titer was present in the lacrimal secretion of 2 out of 7 atopic individuals whose sera showed a high skin-sensitizing antibody titer. Blocking antibody to ragweed was not found in the lacrimal secretion of one treated patient who had an elevated serum blocking antibody titer. Serum protein components found in tears were albumin and beta-2A globulin.

Titers of SSA decreased in 10 of 21 previously untreated patients with hay fever after treatment with injections of aqueous extract for 13 to 48 months. Quantity of antigen injected did not appear to influence the change in titer. Patients with the highest titers before treatment changed least after therapy. All patients with the lowest pretreatment titers showed significant declines in titer after treatment. Fifteen subjects did not receive injections of extract. Titers did not change in 12 and increased in 3 during a period of 2 to 3 years. Titers of SSA were determined in 2 other groups of patients. In one group, treated with aqueous extracts for many years, titers did not change during one additional year of therapy. The average of this group's first titers was low and suggested that previous therapy had caused a decrease in titer during early years of treatment. Forty other patients received repository injections of extract for 3 consecutive years. No difference existed between the average titers of pre- and postreatment sera. Titers of 5 patients in this group increased significantly. Results suggest that aqueous injection therapy frequently causes a decrease in SSA, "hyposensitization." One hypothesis to explain hyposensitization is that injected antigen suppresses antibody synthesis. Hyposensitization may be analagous to partial immune tolerance.

1.1. The intracutaneous skin test tends to vary directly with the skin-sensitizing antibody titer. However, individual variations are so great that titer cannot be determined from the skin test. 2.2. The doses of aqueous ragweed extract tolerated by patients vary inversely with the skin-sensitizing antibody titer. 3.3. Development of blocking antibody increases the tolerance for injected extracts. 4.4. Patients with high titers of skin-sensitizing antibody are more likely to have constitutional reactions to emulsions of ragweed pollen extract even with lower doses of antigen. The titer of skin-sensitizing antibody is a helpful guide in determining the dose of emulsified pollen extract to be used. 5.5. Prolonged treatment with injections of aqueous ragweed extract is accompanied by a decrease in the titer of skin-sensitizing antibody. This decrease is greatest between the first and fifth year of treatment but continues up to 20 years. Comparative studies of untreated patients and of patients who, after 1 or 2 years of treatment, were untreated for an average of 9 years suggest that this decrease in titer of skin-sensitizing antibody results directly from the treatment and not from the increasing age of the patient or duration of hay fever.

It is noted that sera of 5 of 11 patients who have been treated with 5,000 or 10,000 PNU of ragweed extract in mineral oil emulsions contained an anaphylactic type of antibody (or antibodies) capable of inducing passive cutaneous anaphylaxis in guinea pig skin.

Terfenadine is the first of a new class of non-sedating H1 antihistamines. It differs from chlorpheniramine in its lower anticholinergic activity in rabbit salivation tests. In animal model distribution studies, the drug is not found in the brain. In most clinical studies sedation attributed to terfenadine was on the order of that observed with placebo. Clinical trials of efficacy show that at best terfenadine is slightly less effective than or as effective as chlorpheniramine.

In a double-blind study, a timed-release tablet containing carbinoxamine maleate 8 mg and pseudoephedrine hydrochloride 120 mg was compared with placebo for the treatment of signs and symptoms of nasal allergy. Ninety-four adults with rhinitis caused by grass or ragweed allergy were paired according to severity of symptoms and nasal congestion, then assigned randomly to drug or placebo. After baseline measurements were taken, three doses of drug or placebo were given at 12-hour intervals. The active drug was significantly better than placebo in relieving the following symptoms: nasal congestion, nose blowing, sneezing, nasal pruritus, rhinorrhea, ophthalmic pruritus, and sniffles. Improvement over baseline in mean total nasal air flow also was greater in subjects given active drug. The incidence of nonspecific symptoms, including possible drug side effects, was similar between groups. We conclude that the timed-release tablet is safe and effective therapy for the treatment of signs and symptoms of nasal allergy.

Azelastine is capable of interfering with a wide variety of mediators of airway hyperreactivity and provides significant protection and bronchodilation in allergic hay fever and allergic asthma, respectively. Clinical studies have shown that azelastine produces clinically significant bronchodilation of long duration in moderate to severe reversible lower airway disease. In addition, azelastine has been shown to have an effect on the upper airways by effective symptom relief in patients with seasonal allergic rhinitis; furthermore, azelastine affords protection against exercise and allergen provocation.

Pseudoephedrine and triprolidine, administered every 6 hours as a combination, made separate and distinct contributions to the treatment of allergic rhinitis. Furthermore, the combination was perceived by the patients as being clinically superior to either of its components or placebo.

This report describes an instrument which measures the effective cross-sectional area of the nasal airway. The patient breathes into a mask which extends from the upper lip to the forehead and across the cheeks laterally. Two openings in the mask system permit air to flow: one is the nasal airway (N a ) and the other an opening to the atmosphere (M a ), which can be varied. Pharyngeal pressure (P p ) and mask pressure (M p ) are recorded continuously during normal respiration. N a can be calculated in square millimeters by the empirical formula Na=2.5 (Ma) (Mp)Pp. This device offers a number of advantages over previously described instruments. The nose itself is not physically touched. All variables, such as pressures and the opening from the mask to the atmosphere, can be measured with existing equipment. An airway measurement can be made with each inspiration, and patients can be followed for prolonged periods without discomfort. The patient's effort in breathing need not be constant nor must it be strenuous, permitting measurements in the physiologic range.

1.1. Skin sensitizing antibody titers of patients having constitutional reactions to ragweed were significantly higher than those found in any group of skin test, positive, symptomatic or asymptomatic, treated or untreated patients. 2.2. Blocking antibody titers of patients who had constitutional reactions were lower than those found in the group of patients treated with high doses of aqueous extract and in patients who had received the ragweed emulsion, but were comparable to those found in patients receiving a similar amount of aqueous ragweed extract. 3.3. Hemagglutinating titers were similar in patients who had constitutional reactions and in those patients receiving low amounts of aqueous ragweed extract but were less than the post-repository group and the group treated with high doses of aqueous extract.

THE CLINICAL evaluation of the effectiveness and duration of sustained-action antihistamine and decongestant medications is difficult to accomplish because of the all-too-familiar phenomena of widely changing subjective symptoms and of rapidly changing environmental exposure to ever-varying allergens and/or irritants. In addition, final evaluation rests with the patient's subjective determinations or the physician's appraisal made from relatively meager observations. Using a new objective technique, the effect of a sustained-action antihistamine and decongestant medication (Allerest Time Capsules) was studied during environmental exposure to ragweed pollen. Method Six hospital employees who had ragweed hay fever were selected for testing on the basis of availability. All of these individuals performed their usual jobs in the hospital during the experiments. Tests were performed during the ragweed pollinating season. Because subjects were in the same general area, environmental ragweed pollen concentration was assumed to be the same for all. An increase or decrease in symptoms

One normal test subject was sensitized to ragweed pollen antigen emulsified in Freund's adjuvant. Immediate and delayed types of sensitivity were induced. The immediate type of sensitivity was recalled after each booster dose of antigen. Reappearance of the whealing skin reactions after a massive reinjection of antigen in emulsion was accompanied by a marked decrease of the delayed skin reactions. Serum antibodies were determined by various techniques, and the titers followed through 40 weeks.

C-reactive protein (CRP) is a complex glycoprotein found in serum. It is an abnormal, nonspecific, acute-phase protein seen in pregnancy and with tissue injury and necrosis. Sera from 4 groups of patients were studied for CRP. Thirteen per cent of an unselected control group had CRP. Sixty per cent of sera from pregnant patients contained CRP, but sustained increase with advancing pregnancy was not observed. Ninety-two per cent of patients receiving combination contraceptive preparations, 52 per cent receiving sequential contraceptive preparations, and 14 per cent receiving continuous low-dosage progestogen therapy without added estrogen developed CRP. CRP was present in the sera of some patients using intrauterine contraceptive devices (IUD's), and the number of positive reactions appeared to increase with the increased length of use of a device. These data could support a local biochemical contraceptive mechanism of action. Since CRP is apparently produced only by the liver, this study suggests that the IUD may, in addition, produce a systemic stimulus.

Most hypertension can be controlled if treatment is begun early and continued on a long-term basis. Forty-nine patients with blood pressures of 170/100 mm. Hg or greater were studied. All received reserpine; 39 who failed to exhibit an adequate response had hydrochlorothiazide added. Ten patients who did not respond to this combination were given hydralazine in addition; three had an excellent response, five good, one fair, and one none. No significant side-effects were caused by reserpine. Reactions to hydrochlorothiazide included nausea, lightheadedness, and mild skin rash. One patient had skin rash, joint pain, and an elevated blood urea nitrogen level due to hydralazine, which had to be discontinued. Patients who do not respond to this combination of drugs may improve with the use of ganglionic blocking agents or guanidine sulfate. Experience with the latter is too small to warrant evaluation.

The number of mast cells in the bronchial walls of patients who died of asthma was compared to that in walls of nonasthmatic patients. Mast cells are normal components of bronchial wall and contain chemical mediators which can cause changes in bronchial muscle tone and glandular secretion. Physiological amounts of mediator released by normal stimuli may constitute a local homeostatic mechanism for control of some bronchial functions. Unphysiological quantities released by abnormal stimuli could cause bronchospasm, secretion, and edema leading to obstruction typical of that found in asthma. Degranulated mast cells cannot be identified in tissue sections. There were fewer mast cells in bronchi of patients who died of asthma than in those of nonasthmatic patients, which suggests that marked degranulation of mast cells occurred, and is one mechanism associated with the pathophysiology of asthma.