Validation of inducible basophil biomarkers: Time, temperature and transportation.

BACKGROUND: The short stability window of several hours from blood collection to measuring basophil activation has limited the use of flow cytometry-based basophil activation assays in clinical settings. We examine if it is possible to extend this window to 1 day allowing for shipment of samples between laboratories. Several options exist for reporting the results including reporting all the measured values directly, calculating ratios and reporting a single value covering all measured results. Each of these options have different stability and value to the physician. METHODS: Whole blood samples from peanut allergic patients were stimulated with four different peanut concentrations at Day 0, Day 1, and Day 2. Samples were stored under temperature-controlled conditions. Flow cytometry was used to analyze the samples. The basophil activation and degranulation were measured as percentage of positive CD63 basophils and CD203c MFI fold change. Shipped samples were transported under ambient conditions. RESULTS: The results show that CD63 is a stable marker at Day 1. The CD203c ratio decreases significantly at Day 1. Calculating the CD63/IgE ratio proves to be more stable than CD63 alone. The most stable readouts are the semi-quantitative results and the trajectory of the dose response curve. Finally, we confirmed that the stability can be extended to samples shipped overnight to the laboratory. CONCLUSIONS: It is possible to extend the stability of the basophil activation assay to 1 day for samples stored at 18-25°C as well as samples shipped under ambient conditions as long as the temperature is within the 2-37°C range.

A pilot study of omalizumab in eosinophilic esophagitis.

Eosinophilic disorders of the gastrointestinal tract are an emerging subset of immune pathologies within the spectrum of allergic inflammation. Eosinophilic Esophagitis (EoE), once considered a rare disease, is increasing in incidence, with a rate of over 1 in 10,000 in the US, for unknown reasons. The clinical management of EoE is challenging, thus there is an urgent need for understanding the etiology and pathophysiology of this eosinophilic disease to develop better therapeutic approaches. In this open label, single arm, unblinded study, we evaluated the effects of an anti-IgE treatment, omalizumab, on local inflammation in the esophagus and clinical correlates in patients with EoE. Omalizumab was administered for 12 weeks to 15 subjects with long standing EoE. There were no serious side effects from the treatment. Esophageal tissue inflammation was assessed both before and after therapy. After 3 months on omalizumab, although tissue Immunoglobulin E (IgE) levels were significantly reduced in all but two of the subjects, we found that full remission of EoE, which is defined as histologic and clinical improvement only in 33% of the patients. The decrease in tryptase-positive cells and eosinophils correlated significantly with the clinical outcome as measured by improvement in endoscopy and symptom scores, respectively. Omalizumab-induced remission of EoE was limited to subjects with low peripheral blood absolute eosinophil counts. These findings demonstrate that in a subset of EoE patients, IgE plays a role in the pathophysiology of the disease and that anti-IgE therapy with omalizumab may result in disease remission. Since this study is open label there is the potential for bias, hence the need for a larger double blind placebo controlled study. The data presented in this pilot study provides a foundation for proper patient selection to maximize clinical efficacy.

Intravenous anti-IL-13 mAb QAX576 for the treatment of eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic allergic disease with limited treatment options. OBJECTIVE: We evaluated QAX576, an mAb against IL-13, in the treatment of patients with EoE. METHODS: Patients (18-50 years) with proton pump inhibitor-resistant esophageal eosinophilia received intravenous QAX576 (6 mg/kg) or placebo (2:1) at weeks 0, 4, and 8 and were followed for 6 months. The primary end point was the responder rate for a greater than 75% decrease in peak eosinophil counts at week 12. Efficacy was to be declared if the lower 90% confidence limit for the proportion of responders on QAX576 was 35% or greater. Secondary end points included changes in esophageal eosinophil counts, symptoms assessed by questionnaire scores, and quantification of a series of biomarkers. RESULTS: Twenty-three patients completed the study up to week 12, and 18 continued to the end of the study. For the proximal and distal esophageal biopsies combined, the responder rate was 12.5% (90% confidence limit, 1% to 43%) with placebo, compared to 40.0% (90% confidence limit, 22% to 61%) with QAX576. Although the primary end point was not met, the mean esophageal eosinophil count decreased by 60% with QAX576 versus an increase of 23% with placebo (P = .004), and the decrease was sustained up to 6 months. There was a trend for improved symptoms, particularly dysphagia. QAX576 improved expression of EoE-relevant esophageal transcripts, including eotaxin-3, periostin, and markers of mast cells and barrier function, for up to 6 months after treatment. QAX576 was well tolerated. CONCLUSIONS: QAX576 significantly improved intraepithelial esophageal eosinophil counts and dysregulated esophageal disease-related transcripts in adults with EoE in a sustained manner.

Clinical presentation of pyloric stenosis: the change is in our hands.

BACKGROUND: Hypertrophic pyloric stenosis classically presents as projectile vomiting during the third to fourth week of life, associated with good appetite. Additional classical presenting findings include palpation of the pyloric tumor, described as olive-shaped; a visible gastric peristaltic wave after feeding; and hypochloremic, hypokalemic metabolic alkalosis. It was recently claimed that this presentation has changed due to the easier access to gastrointestinal imaging. OBJECTIVE: To validate this contention and discuss possible reasons. METHODS: We conducted a retrospective chart review of all patients who underwent pyloromyotomy for HPS between 1990 and 2000. Only patients with confirmed HPS at the time of surgery were included. We also performed a comprehensive review of older studies for comparison. RESULTS: Seventy patients underwent pyloromyotomy over the 10 year period. Overall, 81% of patients were male infants and the mean age at diagnosis was 40 days. The mean duration of symptoms was 8 days. A firstborn child was noted in 43% of the cases. The classical symptom of projectile vomiting was absent in one-third of the patients, a pyloric tumor was not palpated in one-half of the cases, bicarbonate was higher than 28 mEq/L in 20%, and a pH of above 7.45 was present in 25% of patients. Hypochloremia was noted in about one-third. We found a good correlation between ultrasonographic width and length of the pylorus and the intraoperative findings. Pylorus length +/- 24 mm correlated with significantly longer duration of symptoms. When compared with previous studies, the main findings were not significantly different; namely, mean age at diagnosis, percentage of male gender, and duration to diagnosis. The decrease in the number of pyloric tumors palpated paralleled the increase in the use of upper gastrointestinal series and ultrasonography in particular. CONCLUSIONS: The clinical presentation of HPS has not actually changed despite the easier accessibility of GI imaging studies. However, the one significant change is the low percentage of pyloric tumors palpated, probably due to declining clinical skills accompanied by earlier utilization of imaging studies. The use of imaging and laboratory studies did not change the age at diagnosis but may have shortened the time for diagnosis and reduced the postoperative stay. Imaging and laboratory studies may be helpful for the subgroup with a non-classical clinical presentation.

Acute appendicitis presenting as secretory diarrhea.

A 12-year-old girl presented with lower abdominal pain, nonbilious vomiting, and a severe secretory diarrhea. Infectious and noninfectious etiologies were ruled out, and she was found to have perforated acute appendicitis. It is essential to consider acute appendicitis in the differential diagnosis for secretory diarrhea and abdominal pain in the pediatric population.