Specific IgE toward Allergenic Molecules Is a New Prognostic Marker in Patients with Sézary Syndrome

Background: Sézary syndrome (SS) is the aggressive leukemic form of cutaneous T cell lymphoma characterized by erythroderma, the presence of a malignant circulating T memory cells with skin homing potential, and the ability to produce a variety of Th2 soluble factors, such as IL-4 and IL-5. We measured total and specific IgE in SS patients as a further parameter of a Th2-skewed immune system, and studied their clinical impact. Methods: Specific IgE production in a cohort of 55 SS patients was evaluated by the molecule-based ISAC microarray system. We then evaluated survival times and the hazard ratios in this cohort by Kaplan-Meier and Cox methods. Results: Twenty-four (43.6%) SS patients had specific IgE to both environmental and food allergens. For survival analysis, patients found positive to at least one allergen were defined as IgE+. By comparing IgE+ versus IgE– we found a significant difference in the median survival times, 2.9 versus 8.9 years (p < 0.001). Conversely, no survival difference could be observed when total IgE levels were considered. IgE+ patients had higher levels of CD60+CD49–CD4+ T cells, which also represent another worse prognostic index recently identified. Conclusion: SS patients had specific IgE to both environmental and food allergens. IgE+ SS patients had a significant lower survival rate. High levels of CD60–CD49+CD4+ T cells associated with an IgE– phenotype allow the identification of a restricted group of long survivor SS patients. Therefore, specific measurement of IgE seems to be useful in discriminating survival.