Inflammatory Compounds: Neuropeptide Substance Pand Cytokines

Inflammatory diseases represent one of the major causes of morbidity and mortality throughout the world and they affect the functions of several tissues. The pathophysiology of these diseases involves release of many pro-inflammatory mediators such as cytokines/chemokines, histamine, C3a, C5a (complement components), bradykinin, leukotrienes (LTC4, LTD4, LTE4), PAF, and substance P, in addition to anti-inflammatory molecules. Recently, it has been demonstrated that neuroimmune interactions are important in the initiation and progress of inflammatory processes. Substance P is an 11-amino acid neuropeptide that is released from nerve endings in many tissues. It acts via membrane-bound NK1 receptors (NK1R). Inflammatory and neuropeptides such as substance P stimulate the release of chemokines, in particular IL-8, a potent neutrophil chemoattractant. Expression of IL-8 is regulated mainly by the transcription factors NF-kappaB, activating protein-1. Substance P plays an important role in immunological and inflammatory states, and it is a mediator of tissue injury, asthma, arthritis, allergy and autoimmune diseases. In this article, our studies revisited the interrelationship between these two powerful inflammatory compounds: substance P and cytokines. These observations suggest that these inflammatory molecules may represent a potential therapeutic target to treat several inflammatory states.

Are drug provocation tests still necessary to test the safety of COX-2 inhibitors in patients with cross-reactive NSAID hypersensitivity?

BACKGROUND

COX-2 inhibitors are safe alternatives in patients with cross-reactive non-steroidal anti-inflammatory drug (NSAID) hypersensitivity. These drugs are recommended to these patients after negative drug provocation tests (DPTs). However, cumulative data on encouraging results about the safety of COX-2 inhibitors in the majority of these patients bring the idea as to whether a DPT is always mandatory for introducing these drugs in all patients with cross-reactive NSAID hypersensitivity.

OBJECTIVE

To document the safety of COX-2 inhibitors currently available and to check whether or not any factor predicts a positive response.

METHODS

This study included the retrospective analysis of cases with cross-reactive NSAID hypersensitivity who underwent DPTs with COX-2 inhibitors in order to find safe alternatives. DPTs were single-blinded and placebo controlled.

RESULTS

The study group consisted of 309 patients. COX-2 inhibitors were well tolerated in the majority of the patients [nimesulide: 91.9%; meloxicam: 90.2%; rofecoxib: 94.9%; and celecoxib: 94.9%)]. Twenty-five patients (30 provocations) reacted to COX-2 inhibitors. None of the factors were found be associated with positive response.

CONCLUSION

Our results suggest to follow the traditional DPT method to introduce COX-2 inhibitors for finding safe alternatives in all patients with cross-reactive NSAID hypersensitivity before prescription as uncertainty of any predictive factor for a positive response continues. However, these tests should be performed in hospital settings in which emergency equipment and experienced personnel are available.

Autism and immunity: revisited study

Autism spectrum disorder is of interest neurochemically because it represents a relatively homogeneous disorder with regard to disease development, abnormal cognitive development and intellectual development disturbance. A consistent finding in autistic children is a high number of mast cells and a high level of serotonin which is also found at elevated concentrations in the urine of autistic patients. In addition, a dysfunction of clinical conditions, such as gastrointestinal and immunological symptoms, is frequently noted in autistic children, however, IgE does not appear to be prevalent in these children but probably an increase of cytokines/chemokines produced by mast cells at an early age may play an important role. Therefore an immune hypothesis, involving also autoimmunity, is one possible pathogenetic mechanism in autism. In conclusion, mast cell activation could contribute to immune and neuroinflammatory abnormalities that are evident in patients with autism spectrum disorders.