Variations in the serum levels of soluble CD23, nitric oxide and IgE across the spectrum of American cutaneous leishmaniasis

Serum IgE levels and the expression of low affinity receptor for IgE (FcepsilonRII/CD23) are increased in cutaneous leishmaniasis. The ligation of CD23 receptor by IgE-anti-IgE immune complexes results in nitric oxide (NO) production, which is a critical leishmanicidal factor. Human monocytes/macrophages express FcepsilonRII/CD23 after activation with IFN-gamma and IL-4. In the present study, we assessed the relationship between NO, total and Leishmania-specific IgE and soluble CD23 across the clinical spectrum of American cutaneous leishmaniasis (ACL). Sixty-nine ACL patients and 22 endemic controls were studied. NO concentration was estimated using the Greiss method. Soluble CD23, total IgE and anti-Leishmania IgE levels were measured using ELISA. Soluble CD23 was increased in the four patient groups (0.001 < P < 0.05) compared by the Mann-Whitney test to healthy subjects, particularly in mucocutaneous leishmaniasis (MCL) and diffuse cutaneous leishmaniasis, (DCL) patients. Total IgE levels were higher in ACL patients (P < 0.0001). Anti-Leishmania IgE showed a similar tendency, where MCL and DCL patients had greater levels. All patients groups, except intermediate or chronic cutaneous leishmaniasis (ICL) patients, showed elevated levels of NO2-/NO3- compared to healthy individuals (0.001 < P < 0.01). Interestingly, ICL patients did not produce significant levels of NO2-/NO3-. ACL patients showed a significant positive correlation between soluble CD23 and anti-Leishmania IgE. DCL patients showed a positive correlation between both parameters. Overall results suggest that sCD23, IgE and NO may play different roles across the ACL spectrum. (C) 2003 Elsevier B.V. All rights reserved.