pyrophosphate and Arthritis--Gouty

Microcrystalline arthropathies of the wrist include three main forms of microcrystalline pathology: gout, chondrocalcinosis and apatite calcifications. Gout of the wrist is now rare and may be missed, particularly in its chronic form, occasionally associated with tophi and large, often asymmetrical erosions on the X-rays. Chondrocalcinosis is frequent and easy to diagnose in the wrist and may be responsible for a very typical arthropathy predominantly involving the radiocarpal joint, while the frequency and specificity of scapho-trapezoid involvement are controversial. Apatite deposits in the wrist involve various tendons and ligaments, especially the tendon of flexor carpi ulnaris, but may also be responsible for intra-articular pathology.

Topics: Apatites; Arthritis, Gouty; Carpal Bones; Chondrocalcinosis; Diphosphates; Humans; Joint Loose Bodies; Radiography; Wrist Joint

"Small" (between 75-98% of crystals less than or equal to 10 microns) and "large" (between 81-93% of crystals greater than 10 microns) size fractions of monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate triclinic (CPPD) crystals were incubated with human neutrophils and crystal induced neutrophil cytolysis monitored by measuring the release of lactate dehydrogenase. "Small" size fractions of MSUM and CPPD gave higher percent lysis values than "large" crystals. The binding of high density lipoproteins (HDL) and low density lipoproteins (LDL) to the crystals was quantitated. HDL and LDL bound in significant amounts to both CPPD and MSUM and strongly inhibited CPPD and MSUM induced neutrophil cytolysis. We propose that HDL and LDL bound to MSUM and CPPD may play important roles in the regulation of gouty inflammation.

Topics: Apolipoproteins; Arthritis, Gouty; Calcium Pyrophosphate; Diphosphates; Humans; In Vitro Techniques; Lipoproteins, HDL; Lipoproteins, LDL; Neutrophils; Time Factors; Uric Acid