Spontaneous resolution of hypereosinophilic syndrome in an infant without treatment.

We report on a 4-month-old boy with hypereosinophilic syndrome (HES) and spontaneous progressive resolution without treatment. Differential diagnosis excluded myeloproliferative, lymphocytic, familiar, associated, and overlap HES. The final diagnosis was undefined HES. Repeated measurements of blood eosinophil counts, monitoring of clonal T cells, and observation of skin lesions and organ involvement were carefully performed as an outpatient.

El eosinofilo / Eosinofilo

los eosinófilos son una minoría de los leucocitos de sangre periférica y su presencia en los tejidos se limita principalmente a los sistemas gastrointestinal, respiratorio y genitourinario. Entre sus principales funciones se encuentran; la generación de mediadores inflamatorios, la defensa del huésped y el remodelamiento tisular. En ciertas entidades patológicas estas células pueden acumularse selectivamente en la sangre periférica o en algún tejido corporal, originando alteraciones importantes. Existen múltiples condiciones en las cuales se presenta eosinofilia, entre ellas se destacan especialmente ciertas patologías alérgicas, enfermedades malignas, el rechazo de trasplantes, la hipersensibilidad a medicamentos y las infecciones parasitarias. Establecer un diagnóstico acertado a cada paciente requiere de una detallada evaluación clínica y de la utilización de pruebas de laboratorio más específicas de acuerdo con las condiciones del paciente. Palabras clave: eosinófilo, alergia, asma, dermatitis, helmintiasis, enfermedad maligna. Vanegas-Arroyave N, Campuzano-Maya, G. El eosinófilo. Medicina & Laboratorio 2005; 11: 311-319.Módulo 4 (Hematología), número 8. Editora Médica Colombiana S.A., 2005

Immunostimulatory DNA sequences inhibit IL-5, eosinophilic inflammation, and airway hyperresponsiveness in mice.

We have used a mouse model of allergen-induced airway hyperresponsiveness to demonstrate that immunostimulatory DNA sequences (ISS) containing a CpG DNA motif significantly inhibit airway eosinophilia and reduce responsiveness to inhaled methacholine. ISS not only inhibited eosinophilia of the airway (by 93%) and lung parenchyma (91%), but also significantly inhibited blood eosinophilia (86%), suggesting that ISS was exerting a significant effect on the bone marrow production of eosinophils. The inhibition of the bone marrow production of eosinophils by 58% was associated with a significant inhibition of T cell-derived cytokine generation (IL-5, granulocyte-macrophage CSF, and IL-3). ISS exerted this inhibitory effect on T cell cytokine production indirectly by stimulating monocytes/macrophages and NK cells to generate IL-12 and IFNs. The onset of the ISS effect on reducing the number of tissue eosinophils was both immediate (within 1 day of administration) and sustained (lasted 6 days), and was not due to ISS directly inducing eosinophil apoptosis. ISS was effective in inhibiting eosinophilic airway inflammation when administered either systemically (i.p.), or mucosally (i.e., intranasally or intratracheally). Interestingly, a single dose of ISS inhibited airway eosinophilia as effectively as daily injections of corticosteroids for 7 days. Moreover, while both ISS and corticosteroids inhibited IL-5 generation, only ISS was able to induce allergen-specific IFN-gamma production and redirect the immune system toward a Th1 response. Thus, systemic or mucosal administration of ISS before allergen exposure could provide a novel form of active immunotherapy in allergic diseases.

[Genetic control of hypereosinophilias]. / Le controle genetique des hypereosinophilies.

Polynuclear eosinophils play a major role in host defense against infectious diseases and especially helminthiasis. Onset of hypereosinophilia can be attributed to two mechanisms which can occur separately or in combination. The first mechanism involves enhancement of medullary production and differentiation of eosinophils. The second is prolonged life span of eosinophils. Response to eosinophils depends on various cytokines including IL-5, IL-4, IL-3 and GM-CSF. Since it contains the genes coding for these cytokines, the 5q31-q33 region of chromosome 5 is the focus of study on genetic control of human hypereosinophilia. The goal of these studies is to allow screening of subjects predisposed to helminthic infection and to deregulation of immune responses that may lead to atopy and various types systemic inflammatory diseases.