Atopic diseases of childhood

Cysteinyl-leukotrienes and their receptors in asthma and other inflammatory diseases: critical update and emerging trends

Cysteinyl-leukotrienes (cysteinyl-LTs), that is, LTC4, LTD4, and LTE4, trigger contractile and inflammatory responses through the specific interaction with G protein-coupled receptors (GPCRs) belonging to the purine receptor cluster of the rhodopsin family, and identified as CysLT receptors (CysLTRs). Cysteinyl-LTs have a clear role in pathophysiological conditions such as asthma and allergic rhinitis (AR), and have been implicated in other inflammatory conditions including cardiovascular diseases, cancer, atopic dermatitis, and urticaria. Molecular cloning of human CysLT1R and CysLT2R subtypes has confirmed most of the previous pharmacological characterization and identified distinct expression patterns only partially overlapping. Interestingly, recent data provide evidence for the immunomodulation of CysLTR expression, the existence of additional receptor subtypes, and of an intracellular pool of CysLTRs that may have roles different from those of plasma membrane receptors. Furthermore, genetic variants have been identified for the CysLTRs that may interact to confer risk for atopy. Finally, a crosstalk between the cysteinyl-LT and the purine systems is being delineated. This review will summarize and attempt to integrate recent data derived from studies on the molecular pharmacology and pharmacogenetics of CysLTRs, and will consider the therapeutic opportunities arising from the new roles suggested for cysteinyl-LTs and their receptors.

Rhinosinusitis

Rhinosinusitis is one of the most common health care complaints in this country. The burden on affected individuals in terms of decreased productivity, absenteeism from the workplace, and diminished quality of life, when added to the cost of care and the growing public health menace of antibiotic-resistant bacteria, makes rhinosinusitis a serious disease that warrants precise diagnosis and effective therapy. Technologic innovations in endoscopy and imaging have improved understanding of sinus pathophysiology, but diagnosis remains clinical and treatment empiric. Recognized pitfalls in acute rhinosinusitis management are injudicious use of antibiotics and antihistamines. Chronic rhinosinusitis is a complex, multifactorial disorder, not simply an infectious disease. In many patients, noninfectious inflammation and structural problems play an important role. Medical management should include an intranasal corticosteroid in addition to an appropriate antibiotic. Otolaryngology referral is indicated for complications of acute infection, immunocompromised patients, nasal polyps, and chronic rhinosinusitis having substantial effect on quality of life. Modern surgical principles that focus on obstructive pathology in the OMC region are efficacious but rarely curative. Developments in the fields of immunology, molecular biology, and genetics will lead to more effective treatment options.