Pain and microcrystalline arthritis.

Microcrystals are responsible for some of the most common and complex arthropathies which are often accompanied by intense, severe pain and inflammatory reactions. The main pathogens are crystals of monosodium urate (MSU), responsible for the gout, calcium pyrophosphate (CPP), which deposits also in various clinical forms of arthopathies, and basic calcium phosphate associated with osteoarthritis. In this context, the microcrystal arthritis is characterized by multiple, acute attacks followed by chronic pain, disability, impaired quality of life, and increased mortality. Given their chronic nature, they represent an ever more urgent public health problem. MSU and CPP crystals are also able to activate nociceptors. The pain in mycrocrystalline arthritis (MCA) is an expression of the inflammatory process. In the course of these diseases there is an abundant release of inflammatory molecules, including prostaglandins 2 and kinins. Interleukin-1 represents the most important cytokine released during the crystal-induced inflammatory process. Therefore, clinically, pain is the most important component of MCA, which lead to functional impairment and disability in a large proportion of the population. It is fundamental to diagnose these diseases as early as possible, and to this aim, to identify appropriate and specific targets for a timely therapeutic intervention.