Aplicaciones de la toxina botulínica en glándulas salivales / Application of botulinum toxin in salivary glands

Botulinum toxin is a neuromodulator produced by Clostridium botulinum, a gram-negative, anaerobic bacterium responsible for botulism. The clinical utility of botulinum toxin initially became evident in the treatment of strabismus. Subsequently, botulinum toxin has been used for a variety of other medical conditions such as muscular hyperactivity, including blepharospasm, hemifacial spasm, and cervical dystonia. In addition to its well-known applications, within the properties of botulinum toxin are those that make possible the treatment of various diseases affecting salivary glands and oral cavity. Recently there has been an important development in research and finding new applications in otolaryngology. Recent studies have demonstrated the advantages of botulinum toxin injected into the salivary glands of patients who present drooling, reducing the salivary flow and improving their quality of life. In the same way it has proven to be effective as a treatment of sialocele in patients with parotid gland surgery. In parotid and pharyngocutaneous fistula it has proven effective in reducing the salivary flow, facilitating the closure of the defect. Moreover, in patients with Frey’s syndrome it has been effective reducing symptoms and improving quality of life. It has also been histologically demonstrated its protective effect on the glandular damage in patients undergoing radiotherapy.

BAFF: Una citoquina reguladora de linfocitos B implicada en autoinmunidad y cáncer linfoide / BAFF: A regulatory cytokine of B lymphocytes involved in autoimmunity and lymphoid cancer

BAFF (B cell activating factor belonging to the TNF family) is a cytokine implicated in the survival and maturation of peripheral B lymphocytes and T and B cell activation. BAFF binds to three different receptors: TACI, BCMA and BAFF-R, whose expression is restricted to B and T lymphocytes. BAFF and BAFF-R-deficient mice show a dramatic loss of peripheral B lymphocytes and a severely reduced immune response. In contrast, an enhanced BAFF expression leads to B cell hyperplasia and autoimmunity in mice. In vivo, administration of soluble decoy receptors for BAFF effectively decreases disease progression in various autoimmune mouse models. These evidences render BAFF as a potentially new therapeutic target. Elevated BAFF levels have been detected in the serum of patients with autoimmune diseases, such as Systemic Lupus Erythematosus, rheumatoid arthitis, Sjõgren's syndrome, lymphoid cancers and HIV infection. In addition to BAFF receptors, malignant B cells abnormally express BAFF, which attenuates apoptosis through both autocrine and paracrine pathways. The data suggest that an increase in the expression of BAFF induces an enhanced B and T cell activation and the survival of pathologically active B cells. In this article, we review and discuss the participation of BAFF and its receptors in the immune response and its involvement in immunodeficiency, autoimmunity, infections and lymphoid cancers as well as the currently investigated therapies using BAFF antagonists in the treatment of these diseases.