John M. Fahrenholz

Natural history and clinical features of aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a clinical syndrome characterized by chronic rhinosinusitis, nasal polyposis, asthma and precipitation of asthma, and rhinitis attacks after ingestion of aspirin (ASA) and most other nonsteroidal antiinflammatory drugs (NSAIDs). Although precipitation of asthma attacks by ingestion of ASA and other NSAIDs is considered a hallmark of the syndrome, the respiratory mucosal inflammatory disease process begins and continues in the absence of ongoing or even intermittent exposure to ASA or NSAIDs. The typical patient with AERD is an adult who develops refractory chronic rhinitis in the third or fourth decade of life. The chronic rhinitis evolves into chronic eosinophilic rhinosinusitis with associated nasal polyposis. Anosmia appears in most patients. CT of the sinuses most often demonstrates pansinusitis and patients often undergo multiple sinus operations resulting in only limited temporary benefit. During the evolution of the sinus disease persistent asthma develops. Finally, if patients are exposed to ASA or NSAIDs acute respiratory reactions begin to occur. Despite subsequent avoidance of ASA and other NSAIDs, the respiratory mucosal inflammatory disease persists, often requiring systemic corticosteroids for control of both upper- and lower-respiratory tract symptoms. Adequate control of asthma can often only be accomplished with the simultaneous control of the associated rhinosinusitis. With few exceptions, once AERD develops it remains for the remainder of the patient’s life.

Estrogen and progesterone decrease let-7f microRNA expression and increase IL-23/IL-23 receptor signaling and IL-17A production in patients with severe asthma

BACKGROUND Women have an increased prevalence of severe asthma compared with men. IL-17A is associated with severe asthma and requires IL-23 receptor (IL-23R) signaling, which is negatively regulated by let-7f microRNA. OBJECTIVE We sought to Determine the mechanism by which 17β-estradiol (E2) and progesterone (P4) increase IL-17A production. METHODS IL-17A production was determined by using flow cytometry in TH17 cells from women (n = 14) and men (n = 15) with severe asthma. Cytokine levels were measured by using ELISA, and IL-23R and let-7f expression was measured by using quantitative PCR in TH17-differentiated cells from healthy women (n = 13) and men (n = 14). In sham-operated or ovariectomized female mice, 17β-E2, P4, 17β-E2+P4, or vehicle pellets were administered for 3 weeks before ex vivo TH17 cell differentiation. Airway neutrophil infiltration and CXCL1 (KC) expression were also determined in ovalbumin (OVA)-challenged wild-type female recipient mice with an adoptive transfer of OVA-specific TH17 cells from female and male mice. RESULTS In patients with severe asthma and healthy control subjects, IL-17A production was increased in TH17 cells from women compared with men. IL-23R expression was increased and let-7f expression was decreased in TH17-differentiated cells from women compared with men. In ovariectomized mice IL-17A and IL-23R expression was increased and Let-7f expression was decreased in TH17 cells from mice administered 17β-E2+P4 compared with those administered vehicle. Furthermore, transfer of female OVA-specific TH17 cells increased acute neutrophil infiltration in the lungs of OVA-challenged recipient mice compared with transfer of male OVA-specific TH17 cells. CONCLUSIONS 17β-E2+P4 increased IL-17A production from TH17 cells, providing a potential mechanism for the increased prevalence of severe asthma in women compared with men.

Mechanisms of allergy and clinical immunologyEstrogen and progesterone decrease let-7f microRNA expression and increase IL-23/IL-23 receptor signaling and IL-17A production in patients with severe asthma

BACKGROUND Women have an increased prevalence of severe asthma compared with men. IL-17A is associated with severe asthma and requires IL-23 receptor (IL-23R) signaling, which is negatively regulated by let-7f microRNA. OBJECTIVE We sought to Determine the mechanism by which 17β-estradiol (E2) and progesterone (P4) increase IL-17A production. METHODS IL-17A production was determined by using flow cytometry in TH17 cells from women (n = 14) and men (n = 15) with severe asthma. Cytokine levels were measured by using ELISA, and IL-23R and let-7f expression was measured by using quantitative PCR in TH17-differentiated cells from healthy women (n = 13) and men (n = 14). In sham-operated or ovariectomized female mice, 17β-E2, P4, 17β-E2+P4, or vehicle pellets were administered for 3 weeks before ex vivo TH17 cell differentiation. Airway neutrophil infiltration and CXCL1 (KC) expression were also determined in ovalbumin (OVA)-challenged wild-type female recipient mice with an adoptive transfer of OVA-specific TH17 cells from female and male mice. RESULTS In patients with severe asthma and healthy control subjects, IL-17A production was increased in TH17 cells from women compared with men. IL-23R expression was increased and let-7f expression was decreased in TH17-differentiated cells from women compared with men. In ovariectomized mice IL-17A and IL-23R expression was increased and Let-7f expression was decreased in TH17 cells from mice administered 17β-E2+P4 compared with those administered vehicle. Furthermore, transfer of female OVA-specific TH17 cells increased acute neutrophil infiltration in the lungs of OVA-challenged recipient mice compared with transfer of male OVA-specific TH17 cells. CONCLUSIONS 17β-E2+P4 increased IL-17A production from TH17 cells, providing a potential mechanism for the increased prevalence of severe asthma in women compared with men.

Comparison of the sedating effects of levocetirizine and cetirizine: a randomized, double-blind, placebo-controlled trial

BACKGROUND Compared with placebo, levocetirizine has been found to be less sedating than cetirizine in separate trials. However, whether levocetirizine is less sedating than its parent drug cetirizine has not yet been studied in a randomized trial. OBJECTIVE To determine whether levocetirizine is less sedating than cetirizine. METHODS We conducted a randomized, double-blind, crossover, placebo-controlled trial examining sedation and allergy symptoms in patients with perennial allergic rhinitis who had previously reported significant sedation with cetirizine. Enrollment ran from January 28, 2009, to February 25, 2009. All patients completed the study by April 17, 2009. Thirty patients enrolled, and 29 patients completed the study (1 patient did not return her questionnaire). In a double-blind fashion, the 29 study participants received levocetirizine, 5 mg daily for 1 week, cetirizine, 10 mg daily for 1 week, and an equivalent placebo pill for 1 week in randomized order with washout periods before each treatment arm. At the end of each washout period and each treatment period, participants completed a 1-page questionnaire. This questionnaire included questions about sedation or sleepiness in the form of a modified Epworth Sleepiness Scale, a Likert scale measuring general or global sedation, and allergy symptoms as measured by the total rhinitis symptom score. RESULTS Sedation as measured by both the modified Epworth Sleepiness Scale and the Likert scale was not significantly different between the levocetirizine and cetirizine treatments. CONCLUSIONS In patients with a perceived history of sedation with cetirizine, most were able to tolerate levocetirizine. However, this controlled trial also suggests that many of these patients would tolerate cetirizine if given in a masked manner. Therefore, patients with a history of mild to moderate sedation with cetirizine are unlikely to experience a different sedation profile with levocetirizine.

Accidental needle sticks, the Occupational Safety and Health Administration, and the fallacy of public policy

BACKGROUND Current Occupational Safety and Health Administration (OSHA) guidelines mandate the use of safety needles when allergy injections are given. Safety needles for intradermal testing remain optional. Whether safety needles reduce the number of accidental needle sticks (ANSs) in the outpatient setting has yet to be proven. OBJECTIVE To determine the rate of ANSs with new (safety) needles vs old needles used in allergy immunotherapy and intradermal testing. METHODS Allergy practices from 22 states were surveyed by e-mail. RESULTS Seventy practices (28%) responded to the survey. Twice as many ANSs occurred in practices giving immunotherapy when using new needles vs old needles (P < .01). The rate of ANSs was roughly the same for intradermal testing with new needles vs old needles. CONCLUSIONS These findings further question whether OSHAs guidelines for safety needle use in outpatient practice need revision and if allergy practices might be excluded from the requirement to use safety needles.

Safety of multiple aeroallergen rush immunotherapy using a modified schedule.

Rush immunotherapy (RIT) accelerates the build-up phase of traditional IT. The biggest potential benefit of using RIT is decreased time to symptomatic improvement. However, aeroallergen RIT carries an increased risk of systemic reaction (SR) compared with traditional IT. This study was designed to assess the safety of a modified 1-day multiple aeroallergen RIT protocol. A retrospective chart review was performed of 138 patients from an outpatient, university-based allergy practice who underwent RIT between November 2007 and February 2011. The RIT protocol consisted of eight injections over 5 hours, and stopped at one 10-fold dilution below the maintenance vial. All patients were premedicated on the same day of RIT with prednisone and histamine 1 and 2 receptor blockers. Primary end point observed was rate of SR. One hundred thirty-eight patients received a total of 2911 RIT injections. Thirty- eight patients (28%) had SRs. The SR rate per injection was 1.3%. Most of the reactions (82%) occurred after the last dose of the protocol. No patients with SR had severe anaphylaxis requiring emergency department support or hospitalization. The post-RIT SR rate was within the range seen with traditional IT. Well-controlled asthmatic patients were not at increased risk of SR compared with nonasthmatic patients. Modification of RIT to end at one 10-fold dilution below the maintenance vial for multiple aeroallergen RIT did not significantly decrease the SR rate compared with other protocols that end at the maintenance vial. Unlike hymenoptera RIT, aeroallergen RIT continues to be associated with a high risk of SR compared with traditional IT.

Use of olopatadine ophthalmic solution and reactivity of histamine skin testing.

The significant morbidity of allergic rhinitis and allergic conjunctivitis necessitates that diagnosis must be as accurate as possible. However, the very drugs used to treat allergic symptoms have been found to suppress histamine-induced skin testing, making the diagnosis very challenging. Oral formulations of antihistamines are well known to diminish skin test reactivity, but ocular application has never been studied to our knowledge. This study was performed to evaluate whether olopatadine hydrochloride 0.2% ophthalmic solution suppressed histamine-induced wheals and flares on skin-prick testing. A randomized, double-blinded, placebo-controlled, single-center, cross-over pilot study was performed that compared histamine-induced wheal and flare areas after 7-10 days of treatment with both olopatadine 0.2% ophthalmic solution and artificial tears, allowing for a 7- to 10-day washout period between medications. From a total of 24 patients randomized, 21 subjects completed the study, 86% of whom were female. There were no statistically significant differences among both the wheal and the flare areas when comparing treatment with olopatadine and placebo, under the 5% significance level. Although characterized by a small sample size and a preponderance of female subjects, our data suggest that olopatadine does not suppress wheal and flare areas during allergy testing, and discontinuation in preparation for skin-prick testing does not appear to be necessary.

Diagnostic utility of concentrated Mus m 1 allergen extract in humans

There is growing evidence that the mouse allergen is a major causative factor for allergic rhinitis, conjunctivitis, and asthma in children and adults of urban and rural populations.1 Furthermore, exposure to mice by laboratory animal workers is associated with a high risk of developing occupational allergies.2 Our Allergy practice at Vanderbilt University has recognized a number of patients with poorly controlled allergies to the mice that they work with. This clinical observation prompted an investigation for a better diagnostic and therapeutic option for our patients. The major mouse allergens belong to the lipocalin family of proteins that are synthesized in the mouse liver and secreted in the urine. The major mouse allergen is known as Mus m 1 in the allergen nomenclature. Although detectable in serum and pelt extracts, Mus m 1 concentration is 10 times greater in mouse urine than serum.3 Yet, currently the only commercially available mouse extracts are mouse epithelial extracts which contain varying low concentrations of the major mouse allergen Mus m 1 (0.5–8 µg/mL).4 We hypothesized that a highly concentrated major mouse allergen extract suitable for mouse allergy testing in humans could be isolated from mouse urine. The purpose of the study was to develop a new method for preparing mouse urine allergen extract and assess its diagnostic properties in humans. Volunteers underwent skin prick testing and intranasal challenge with the mouse urine extract to determine the diagnostic performance. To our knowledge, this is the first study to determine the diagnostic performance of mouse urine extract. We asked ALK-Abello Laboratory (Round Rock, TX) to prepare a new mouse urine extract to use in our investigation. Mouse urine collected from male laboratory mice was stored frozen until tested for Mus m 1 (Indoor Biotechnologies, Charlottesville, NC). Urine, containing 2,000 to 3,000 µg/mL of Mus m 1 was dialyzed using 0.4% phenol in normal saline, and then diluted to a concentration of 100 µg/ml. The final extract contained 100 µg/mL of Mus m 1 in 50% glycerin, 0.9% NaCl and 0.4% phenol. Qualitative analysis of protein content in the new mouse urine extract and the commercial mouse epithelial extract (ALK-Abello) were analyzed by reversed-phase liquid chromatography-tandem mass spectrometry.5 Thirty nine healthy individuals (32 women, 7 men, age 18–60 years) with a history of mouse exposure were recruited from Vanderbilt University by means of mass e-mail and advertisement. Volunteers consented verbally and in writing to the protocol that was approved by the Vanderbilt University Committee for the Protection of Human Subjects. An Investigational New Drug agreement with the U.S. Food and Drug Administration for the use of mouse urine extract for skin testing and nasal provocations in humans was in place prior to initiation of the study. Subjects discontinued any medications that could interfere with testing at least 5 days prior to the study. Patients completed a questionnaire to assess mouse-related allergic symptoms and exposure. Volunteers then underwent skin prick testing with common aeroallergens (cat and dog hair, mixed mites, German cockroach, alternaria, cladosporium, Bermuda grass, Johnson grass, pecan pollen, oak, cedar, ragweed, mixed lambs quarter) and the commercial mouse epithelial extract (ALK-Abello). Subsequently, volunteers underwent titrated skin prick testing to the new mouse urine extract. Normal saline was added to the mouse urine extract containing 100 µg/mL of Mus m 1 to produce concentrations of extract ranging from 0.33 µg/mL to 100 µg/mL. Skin prick testing to the new mouse urine extract started at 0.33 µg/mL if positive to the commercial mouse epithelial extract or 1 µg/mL if the subject was negative to the commercial mouse epithelial extract in prior testing. Regardless of the starting point, the dose was then increased by ½ log increments until the subject was considered positive or reached the maximum concentration of 100 µg/mL. Allergy testing was performed using standard guidelines and was considered positive if the wheal was ≥3 mm than negative control at 15 min post-exposure.6 Intradermal testing was not done. In addition, all volunteers, regardless of symptoms, underwent nasal challenge to the new mouse urine extract using the procedure described by Bousquet and colleagues.7 The starting point for the nasal challenge depended on the titrated skin test results and clinical symptoms to mice, as evaluated by the mouse symptom and exposure survey. Each challenge was 0.1mL of full strength mouse extract diluted with 0.9% NaCl beginning with glycerin control followed by increases in concentration of mouse allergen extract until a positive challenge or maximum dose (100 µg/mL) was reached. A positive challenge was determined by using a 13-point symptom score of sneezing, pruritis, rhinorrhea, nasal blockage and ocular symptoms.8 Each symptom was graded by the participant and accumulated to give a total score for each incremental challenge, including the glycerin control.9 The nasal challenge was considered positive if the subject had a non65 cumulative symptom score of ≥5. All participants tolerated the experiments well. The primary statistical objective was to compare the results of the titrated skin prick testing and nasal challenge of the new mouse urine extract. The sensitivity, specificity, positive predictive value and negative predictive value of the titrated skin prick test were calculated using 95% confidence intervals for each of these values by employing the Wilson score-test-based method for calculating confidence intervals for binomial probabilities and R (www.r-project.org) software. Qualitative reversed-phase liquid chromatography-tandem mass spectrometry analysis of the mouse urine extract revealed approximately 26 mouse urine proteins and a minute amount of albumin. In contrast, the commercial mouse epithelial extract contained more than 267 proteins including high amounts of albumin, diverse bioactive proteins including heat shock proteins and other poorly characterized proteins with only small quantities of mouse urine proteins. The mouse exposure and symptom survey was completed by 39 volunteers. These volunteers were exposed to mice on average 14 hours per week. Ninety two percent of participants (36/39) handled mice as laboratory workers. Self diagnosis of allergy to mouse and other aeroallergens based on nasal, ocular, respiratory and skin symptoms was reported by 23/39 (59%) and 29/39 individuals (74%), respectively. Thirty seven had interpretable skin prick testing (2 individuals had dermatographism). Among these 37 patients, 28 (76%) had a positive test with at least one aeroallergen, 13 (35%) with the mouse epithelial extract, and 9 (24%) with the mouse urine extract. Nasal challenge with the mouse urine extract was completed in 35 participants. Two volunteers were excluded from the study because they developed reaction to glycerin control either on skin testing or nasal challenge. Out of the 9 subjects with positive skin test to the mouse urine extract, 8 reported symptoms on the survey, and 7 were positive to nasal challenge using mouse urine extract. All subjects with negative mouse symptom questionnaires had negative nasal challenges. The sensitivity of the new mouse urine extract was 70% (7/10), specificity 92% (23/25), positive predictive value 78% (7/9), and negative predictive value 88% (23/26). The most important characteristics of allergen extracts used for diagnostic challenges and immunotherapy include chemical purity and predictable concentration of the specific antigen. We describe a new mouse urine extract that has a greater concentration of the major mouse allergen Mus m 1 and chemical purity than the commercially available mouse epithelial extract. The urine extract contains mostly mouse urine proteins, whereas the epithelial extract is a mixture of albumin, nonspecific proteins including heat shock proteins with a small amount of Mus m 1. However, despite the improved purity, the mouse urine extract did not demonstrate a clear improvement in diagnostic performance over the previously published data of the diagnostic performance of the mouse epithelial extract.4 Comparative performance is revealed in table 1. Table 1 Comparative Performance of Mouse Urine Extract to Mouse Epithelia Extract These results may suggest that Mus m 1 is not the only allergen causing clinical symptoms to mice. There are studies suggesting that serum albumin may also play an etiologic role in mouse allergy in humans.10 Serum albumin is abundantly present in the mouse epithelial extract. Perhaps, the optimal diagnostic method for mouse allergy should include testing with both Mus m 1 and albumin proteins. Importantly, it is also possible, that the reaction to the highly impure epithelial extract is mediated by both IgE and non-IgE mediated inflammatory pathways, thus only in part assessing a true allergic response to mouse. Thus, we describe a new mouse allergen extract containing pure and highly concentrated mouse urine protein that is suitable for diagnostic purposes in humans. Therefore, in our opinion, despite comparable diagnostic efficacy, the newly described urine extract could be superior to the epithelial extract as a diagnostic and research tool for mouse allergy in humans. Furthermore, if we assume that human allergy to mice is similar to cat and dog in which there is a dose dependent response to the major allergen in immunotherapy, then in the future this new extract could be used to develop desensitization methods based on dose of major allergen.11,12 This could give laboratory workers as well as children and adults with severe allergy and asthma to mice an option for relief that was previously never available.

Acute Rejection of a Kidney Transplant in a Patient With Common Variable Immunodeficiency: A Case Report

Common variable immunodeficiency is a primary immunodeficiency characterized by hypogammaglobulinemia and recurrent bacterial infections. We report a case of a 44-year-old male patient with end-stage renal disease and an established diagnosis of common variable immunodeficiency who underwent a living unrelated kidney transplant. He remained nearly infection free on maintenance immunoglobulin replacement. However, his posttransplant course was complicated by acute rejection that ultimately led to allograft loss. This case illustrates the challenge of transplantation in this patient population because of the delicate balance that must be achieved between maintaining adequate immunosuppression and minimizing the risk of infection.

Omalizumab Treatment for Prevention of Anaphylaxis

Opinion StatementRCTs utilizing a specific treatment followed by meta-analysis of multiple RCTs for the specific treatment are the cornerstone of evidence-based medicine. This approach provides key insights into the average response of a therapeutic agent in the selected patient population for the target disease. Generally speaking, a developing trend is more investigations of medical therapies aiming to describe individual patient variability; further, such investigations typically aim to discover and subsequently understand this variability based on biomarkers or even disease-specific genetic polymorphisms among patients. This research returns us to the examination room where we treat individual patients. Given the complexity of idiopathic anaphylaxis and the currently available literature, we believe the time is now to initiate treatment trials of omalizumab in patients not well controlled with prior standard therapy. The use of prolonged systemic steroids should be avoided in favor of a trial of omalizumab. We do not intend to minimize the importance of double-blind placebo-controlled trials. However, based on the full spectrum of current evidence, we do not want to be blinded at the present time by the absence of a published RCT specific to idiopathic anaphylaxis.