Karen S. Hsu Blatman

Desensitizations for Chemotherapy and Monoclonal Antibodies: Indications and Outcomes

Acute infusion reactions to both chemotherapeutic agents and humanized monoclonal antibodies can occur, which may limit therapeutic options for treatment of malignancies and chronic inflammatory diseases. Many of these acute infusion reactions are consistent with a type I hypersensitivity reaction, including anaphylaxis. If a patient experiences a significant acute infusion reaction, often the recommendation is to discontinue the medication and find an alternative agent. However, the “second-line” agent may be more toxic or inferior. If the reaction is likely a type I or type IV hypersensitivity reaction, one option is to undergo desensitization to the offending drug. Drug desensitization is the process of readministering a needed drug in incremental doses over hours or days until a full therapeutic dose is tolerated. This article will review the current literature on indications and outcomes for drug desensitization in the management of allergy to either chemotherapeutic agents or monoclonal antibodies.

Mo1843 Mast Cell Densities on Esophageal Mucosal Biopsies Were Higher in Eosinophilic Esophagitis Versus Proton Pump Inhibitor-Responsive Esophageal Eosinophilia in Adults

Background: Eosinophilic esophagitis (EoE) is a chronic inflammatory condition which causes esophageal remodeling and stricture formation over time. Aim: To explore the natural course of symptoms, endoscopic findings to include stricture development, and histology in EoE patients. Methods: EoE adult patients (age > 18 years) were prospectively enrolled from databases of two medical centers (Walter Reed and Mayo Clinic Jacksonville). All EoE patients were diagnosed per recent consensus guidelines. All patients completed index and follow-up symptom surveys. Endoscopic features (rings, furrows, plaques, strictures) and histology from index and follow-up endoscopies were recorded. Disease behavior was classified as inflammatory if endoscopic findings demonstrated furrows or white plaques and classified as fibrostenotic if endoscopic findings included rings or strictures. Results: 165 EoE patients were identified, mean age 42 ± 14 years; 88.5% Caucasian and 70% male. Median (range) duration of symptoms prior to EoE diagnosis was 66 months (0.1-425). Median follow-up time was 19.2 months (0.9-120). At index, the majority (124/165, 75%) presented with fibrostenotic EoE and 25% (41/165) presented with inflammatory disease. Patients who presented with a stricture had a significantly longer duration of symptoms prior to diagnosis (130 vs 86 months, p=0.011). Patients with fibrostenotic features had more food allergies than those with inflammatory disease (23.4% vs. 4.9%, p=0.010); otherwise, other allergic conditions were similar. At index endoscopy, significantly more patients with fibrostenotic disease had dense proximal eosinophilia (>15 eos/hpf) than patients with inflammatory disease (81.1% vs. 64.3%, p=0.015), but were similar in degree of distal eosinophilia (86.4% vs. 85.3%, p=0.415). Over time, disease behavior remained unchanged in the majority (87.3%, 144/165) of patients. Of the 41 patients presenting with inflammatory disease, 21 patients (51%) developed fibrostenotic features with 15 of these developing a stricture at follow-up endoscopy. Patients who developed fibrostenosis had more dense eosinophilia on biopsies (proximal 68.4% vs. 20.0%, p=0.015; distal 68.2% vs. 36.8%, p=0.049) than those who maintained inflammatory features. The majority of patients (68%) reported improved symptoms over time regardless of their disease behavior. Conclusions: The majority of patients with EoE present with or develop fibrostenotic disease. Duration of symptoms was significantly greater in patients presenting with stricture. Dense proximal esophageal eosinophilia is associated with the presence of fibrostenosic disease and higher levels of eosinophilia may predict transformation from inflammatory to fibrostenotic disease.