Immunotherapy for asthma: unfavorable studies.

INTRODUCTION: Many studies have demonstrated efficacy of immunotherapy (IT) for asthma. Two meta-analyses reached the same conclusion. Because some studies failed to demonstrate efficacy, it is instructive to review reasons why that may have been the case. METHODS: Two meta-analyses were used to identify studies that did and did not demonstrate efficacy. These were reviewed to identify the sources of variability. RESULTS: Most studies are able to demonstrate a treatment effect of IT although they have wide confidence intervals. The studies were heterogeneous with respect to selection of subjects, underlying populations, the main treatment protocol, concomitant treatments, the duration of treatment and followup, and the effect of the protocol on concurrent treatment. There were also problems with the blinding. In most cases, it was difficult to determine how the doses of extract given compared between studies. CONCLUSIONS: Studies that fail to demonstrate a treatment effect of IT may do so for many reasons. Given the heterogeneity of IT clinical trials as a group, it is not surprising that variable results occur. The use of multiple studies in a meta-analysis with its underlying assumption of homogeneity is problematic.

Immunotherapy for inhalant allergies. Guidelines for why, when, and how to use this treatment.

Great-grandma was probably on the right track when she said, "A little dirt won't hurt you. It builds immunity." In fact, some evidence suggests that our "hygienic" environment may be increasing our vulnerabilities to some maladies, especially allergic disorders. Although the principles of immunotherapy have been known for nearly a century, guidelines for its use are still evolving. In this article, Dr Portnoy discusses the role of immunotherapy in patients with symptoms triggered by airborne allergens.

The role and abatement of fungal allergens in allergic diseases.

Sensitivity to a variety of fungi is known to be a factor in allergic rhinitis and asthma. In this review methods for measuring exposure to fungi in the indoor environment are evaluated. A variety of markers for the presence of fungi are also described in addition to their known relationship to either toxic or adverse immunologic effects. Key studies documenting the clinical effects of different types of fungi are also reviewed, as well as a description of abatement methods that either have been successful or need further investigation. Although many studies have shown an association between exposure to fungi and allergic disease, in many cases a direct cause-and-effect relationship has not been established. Improved knowledge of the epidemiology and mechanisms behind fungal-induced human disease will hopefully establish this causal link and suggest methods for reducing morbidity.

Algorithm for the diagnosis and management of asthma: a practice parameter update: Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology, and the Joint Council of Allergy, Asthma and Immunology.

This algorithm on the diagnosis and treatment of asthma is intended to complement and update the previously published Practice Parameters for the Diagnosis and Treatment of Asthma. Both documents were developed by the Joint Task Force on Practice Parameters, representing the AAAAI, ACAAI, and the JCAAI. The authors of this asthma algorithm have attempted to include all the elements essential for the diagnosis and care of patients with asthma. Every effort was made to keep the algorithm clear and concise, yet thorough and complete (Fig 1). Each component of the algorithm is elaborated further in a brief annotation. For further discussion, the reader is referred to the more extensive Practice Parameters for the Diagnosis and Treatment of Asthma.

Alpha-2A-interferon for treatment of bronchiolitis caused by respiratory syncytial virus.

Alpha-2a-interferon (IFN) has been shown to provide important local defense against some viral infections. In vitro, IFN inhibits the growth of respiratory syncytial virus in bovine monolayer cultures, but respiratory syncytial virus is known to be a poor inducer of IFN in infected infants. When IFN was administered by daily intramuscular injection in a double blind, placebo-controlled study of 22 infants with bronchiolitis caused by respiratory syncytial virus, there was no statistically significant difference in clinical course, duration of oxygen requirement or physical assessment between the treatment and control groups. Likewise viral isolation showed no difference between the groups. Further studies are needed to determine whether higher dosing or aerosol or other alternative route of delivery of IFN might lead to therapeutic benefit.

Normal cerebrospinal fluid values in children: another look.

Cerebrospinal fluid samples sterile for virus and bacteria from 371 patients who had no evidence of CNS pathology were examined. The patients were divided into five age categories. The white blood cell polymorphonuclear, and mononuclear cell counts were evaluated. The frequency distributions for these cell counts were markedly skewed, so values were calculated as percentiles for each age group. WBC values were highest for CSF obtained from patients in younger age categories, but 25% of patients from all age categories had two or three WBCs in their CSF. Patients from all but the 3- to 6-month category had three polymorphonuclear cells in their CSF 5% of the time. There was no significant difference in CSF WBC count between patients who had seizures and those who did not. Knowledge of normal values in different age groups is needed for the interpretation of CSF findings, but it should be used in conjunction with other clinical and laboratory findings.

Effects of denervation and tenotomy on the gastrocnemius muscle in the frog: a histologic and histochemical study.

The effects of denervation on the gastrocnemius muscle of the frog were studied by histologic and histochemical methods. Thirteen Rana pipiens underwent unilateral sciatic neurotomy and were sacrificed weekly as long as 46 days. Of the three normal populations of muscle fibers, the small fibers underwent atrophy, the intermediate sized fibers remained unchanged in size, and the large fibers either did not change or underwent hypertrophy between 21 and 46 days. Necrosis of muscle fibers did not occur. Histochemical stains showed persistence of the normal pattern after denervation. The small fibers continued to have a high concentration of both oxidative and glycolytic enzyme activity (NADH-TR, SDH, phosphorylase), and the large fibers continued to have a low concentration of these enzymes. Depletion of glycogen stores was seen with PAS. Hypertrophic muscle fibers had mostly subsarcolemmal nuclei and few internal nuclei, suggesting that they may be physiologically tonic rather than twitch fibers. Achilles tenotomy at the time of denervation prevented the hypertrophy of large fibers. Abnormal inclusions have been demonstrated in mammalian muscle following tenotomy alone, but were not seen in the frog.